POSTER SESSION 3

EP Europace, Jun 2015

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POSTER SESSION 3

P817 Phenotypic profiling to determine individuals at risk for atrial fibrillation: A latent class clustering analysis of the PREVEND cohort M. Rienstra M. Rienstra B. Geelhoed B. Geelhoed J.E. Siland J.E. Siland R.A. Vermond R.A. Vermond P. Van Der Harst P. Van Der Harst H.L. Hillege H.L. Hillege I.C. Van Gelder I.C. Van Gelder University Medical Center Groningen, Cardiology , Groningen , Netherlands Abstract Introduction: The clinical and pathophysiological heterogeneity variety of risk factors predisposing to AF is large. Better understanding of the phenotypic heterogeneity of those at risk for AF may allow better risk prediction. Latent class clustering analyses may allow the identification of clusters of individuals that share similar risk factors (specific profile), instead of the traditional analysis of specific risk factors of AF. Methods: We determined the risk of AF using a hypothesis-free, latent class clustering approach, and compared the performance with a traditional risk-factor-based AF prediction model in the community-based PREVEND cohort. Results: The mean age of the 8,265 individuals was 49±13 years, and 49.8% were men. During 10-year follow-up, 250 (3%) individuals developed AF. We build a latent class model based of uncorrelated risk factors (Figure). The model with 6 distinct classes gave the optimum tradeoff between a high statistical likelihood and a low number of model parameters. The smallest class included 347, the largest 2590 individuals. All clusters had a specific profile (Figure). The incidence of AF varied; being 0.7% (class 1), 1.9% (class 2), 1.4% (class 3), 7.0% (class 4), 4.6% (class 5), and 15.0% (class 6; logrank p<0.001). Internal validation was done with parametric bootstrapping. The discrimination (C-statistic 0.805 vs 0.817, delta-C -0.012, p=0.18) and reclassification (IDI -0.013, p=0.008, NRI -0.013, p=0.73, and categoryless NRI -0.081, p=0.22) performance of the cluster-based model was comparable to the traditional risk-factor-based AF model. Conclusion: Despite the heterogeneity between individuals at risk for AF, latent class clustering produces mutually exclusive groups of individuals with AF risk factors, and is feasible and clinically valid. Figure P818 P wave duration/morphology and left atrial volume at computed tomography in patients without and with (paroxysmal or persistent) atrial fibrillation A. Cima A. Cima M. Brunelli M. Brunelli S. Raffa S. Raffa A. Grosse A. Grosse M. Frommhold M. Frommhold T. Daehne T. Daehne A. Madaffari A. Madaffari C. Lindemann C. Lindemann J.C. Geller J.C. Geller Zentralklinik Bad Berka, Arrhythmia and Electrophysiology Section, Division of Cardiology , Bad Berka , Germany Abstract Introduction: P wave duration of ≥120msec (left atrial enlargement, LAE) and/or advanced degree of interatrial block (IAB, biphasic +/- P waves in the inferior leads) are ECG parameters used to describe LA anatomical and electrical remodeling. Aim of this study was to describe the incidence of LAE and IAB in a large series of patients (pts) without, with paroxysmal or persistent atrial fibrillation (AF) and compare ECG findings with LA volume measured with computed tomography (CT). Methods: ECG (50mm/s) P wave duration (msec) and morphology (bimodal P wave, identified by 2 clearly separated peaks, biphasic p wave ≈ 50% of second component with opposite polarity) were analyzed within 3 days of a 64-slice dual source CT of the heart (Siemens, acquisition in sinus rhythm during ventricular diastole) in pts without, with paroxysmal or persistent AF, and LA volume was calculated (in ml, excluding the veins) and normalized for body surface area. Results: 305 pts [83 (27%) without (no) AF, 112 (37%) paroxysmal and 112 (36%) persistent AF, median age 60 (52, 68) years, 122 (40%) females, 40 (15, 79) months since first AF detection] were enrolled. P wave duration positively correlated with LA volume (Pearson 0.4961; P<.0001), and P wave duration [100 (100, 110) vs. 120 (110, 140) vs. 140 (130, 160) msec] and LA volume [41 (35, 52) vs. 54 (46, 63) vs. 67 (60, 79) ml/m2] were significantly different between no, paroxysmal and persistent AF (P<.0001). The No AF group had a significantly higher rate of positive P waves in lead I and II (82% vs. 37% vs. 32%, P<.0001) whereas the rate of +/- or +/flat P wave in lead III and aVF (12% vs. 25% vs. 33%, P=.0020) and of LAE (37% vs. 72% vs. 97%, P<.0001) was higher in both AF groups. A +/- P wave in V1 was more frequently seen in no and paroxysmal AF groups (76% vs. 85% vs. 69%, P=.0212). Conclusion: P wave duration positively correlates with LA volume. A progressive increase in LA Volume and rate of LAE at ECG is observed when pts without, with paroxysmal and persistent AF are compared. Presence of AF (particularly of its persistent form) is associated with higher rates of IAB due to compromised Bachmann bundle conduction. P819 Prediction of atrial arrhythmia after transcatheter closure of atrial septal defect J.K. Hwang J.K. Hwang 1 Samsung Medical Center, Cardiology department , Seoul , Korea, Republic of K.M. Park K.M. Park 1 Samsung Medical Center, Cardiology department , Seoul , Korea, Republic of S.J. Park S.J. Park 1 Samsung Medical Center, Cardiology department , Seoul , Korea, Republic of Y.K. On Y.K. On 1 Samsung Medical Center, Cardiology department , Seoul , Korea, Republic of J.S. Kim J.S. Kim 1 Samsung Medical Center, Cardiology department , Seoul , Korea, Republic of S.W. Park S.W. Park 1 Samsung Medical Center, Cardiology department , Seoul , Korea, Republic of I.S. Kang I.S. Kang 2 Samsung Medical Center, Pediatric department , Seoul , Korea, Republic of J.Y. Song J.Y. Song 2 Samsung Medical Center, Pediatric department , Seoul , Korea, Republic of J. Huh J. Huh 2 Samsung Medical Center, Pediatric department , Seoul , Korea, Republic of Abstract Purpose: Atrial arrhythmia is a well-known long term complication of atrial septal defects (ASD) in adults even after transcatheter closure. However, the predictors of occurrence of atrial arrhythmia are still unclear. Methods: We investigated 571 consecutive patients with ASD undergoing transcatheter closure from Jan. 2000 to Mar. 2014. Atrial arrhythmia was defined as atrial fibrillation (AF) and flutter (AFL), atrial tachycardia, and supraventricular tachycardia and it was assessed using 12-lead electrocardiogram or 24 hours ambulatory Holter monitors. Demographic, clinical, electrocardiographic and echocardiographic data were analyzed to predict occurrence of atrial arrhythmia after ASD closure. Results: The median age at ASD closure was 37 years (interquartile range: 18-48 years), and 404 (70.8%) were female. Before the index procedure, atrial arrhythmia was documented in 26 (4.6%) patients and the incidence was increased with age (p < 0.01). During the follow-up period (median: 1.3 years, interquartile range: 0.5-3.4 years), a total of 18 (3.2%) patients have developed new onset of atrial arrhythmia. The incidence of new onset atrial arrhythmia, however, was insignificantly different among the ages (p = 0.08). In multivariate analysis, transient AF/AFL during closure (OR: 8.57, 95% CI: 1.59-46.14, p = 0.01) were significantly related with new onset atrial arrhythmia after closure. Conclusions: Transient AF/AFL during closure may be predictive factors of occurrence of atrial arrhythmia. More intensive monitoring to detect occurrence of atrial arrhythmia is needed in this "at-risk" patients. P820 Clincial response predictors in patients undergoing Cardiac Resyncrhonization Therapy (CRT): 7 years follow up R. Ramirez Rodriguez R. Ramirez Rodriguez 1 Doctor Negrin's Hospital , Las Palmas G. C , Spain A.M. Ramirez Rodriguez A.M. Ramirez Rodriguez 2 Insular Hospital , Las Palmas G. C , Spain A. Delgado Espinosa A. Delgado Espinosa 1 Doctor Negrin's Hospital , Las Palmas G. C , Spain A. Medina Fernandez-Aceytuno A. Medina Fernandez-Aceytuno 1 Doctor Negrin's Hospital , Las Palmas G. C , Spain E. Hernandez Ortega E. Hernandez Ortega 1 Doctor Negrin's Hospital , Las Palmas G. C , Spain A. Garcia Quintana A. Garcia Quintana 1 Doctor Negrin's Hospital , Las Palmas G. C , Spain M. Blanco Nuez M. Blanco Nuez 1 Doctor Negrin's Hospital , Las Palmas G. C , Spain Abstract Introduction: Although results of large clinical trials support the role of Cardiac Resynchronization Therapy (CRT) as an important therapeutic option in heart failure (HF), 30% of individual patients do not improve clinically after CRT. Aim: To evaluate the factors associated with the clinical outcome of patients undergoing CRT (survival, cardiac remodling, responders rate). Methods: The study population consisted of 216 patients (75% men, mean age 69±05years). The underlying etiology of cardiomiopathy was ischaemic in 45% of patients. Upgrade 44 patients (20%). Definition of remodeling: LVEF improvement 5% or left ventricular end-systolic diameter (LVESD) reduction ≥10mm. Definition of non responder: Absence of improvement of NYHA functional class, hospitalization due to heart failure or death. Results: 46 patients (21%) died during follow up. 85 patients (40%) were hospitalized due to decompesated heart failure. 70% patients had a gradient of eyection fraction (EF) ≥5% and 36% a reduction of the gradient of LVESD. The survival have the electrode in lateral position (p≥0.021) and 127 patients had atrial fibrillation with a duration of QRS about 156mm (129-190). Conclusions: The patients with atrial fibrilation, broader QRS and non-remodeling were associted to a higher mortality. A lower basal LVEF and the coexistence of coronary artery disease were not associated to a worse prognosis. Multivariate Survival Predictors Effect Odds Ratio (95 confidence limits) p QRS≥170 1,855(1,078-3,192) 0.026 AF 1.976(1,143-3,416 <0.0015 No-remodeling 5,180(2,844-9,434) <0.001  Effect Odds Ratio (95 confidence limits) p QRS≥170 1,855(1,078-3,192) 0.026 AF 1.976(1,143-3,416 <0.0015 No-remodeling 5,180(2,844-9,434) <0.001  AF: Atrial fibrillation Multivariate Survival Predictors Effect Odds Ratio (95 confidence limits) p QRS≥170 1,855(1,078-3,192) 0.026 AF 1.976(1,143-3,416 <0.0015 No-remodeling 5,180(2,844-9,434) <0.001  Effect Odds Ratio (95 confidence limits) p QRS≥170 1,855(1,078-3,192) 0.026 AF 1.976(1,143-3,416 <0.0015 No-remodeling 5,180(2,844-9,434) <0.001  AF: Atrial fibrillation P821 Investigation of the frequency of spontaneous echo contrast and the predictors of left atrial appendage sludge or thrombus formation in patients with atrial fibrillation/flutter T. Onodera T. Onodera Shizuoka City Shizuoka Hospital , Shizuoka , Japan R. Nawada R. Nawada K. Murata K. Murata Y. Watanabe Y. Watanabe H. Sugiyama H. Sugiyama S. Kageyama S. Kageyama N. Hosoya N. Hosoya K. Kodama K. Kodama M. Ishida M. Ishida R. Takeuchi R. Takeuchi Abstract Purpose: Recently it is thought that left atrial appendage (LAA) sludge as well as thrombus causes thromboembolic events. The aim of this study was to estimate the frequency of spontaneous echo contrast (SEC) by transesophageal echocardiography (TEE) and to investigate the predictors of sludge or thrombus in patients with atrial fibrillation and/or flutter (AF/AFL). Methods: One hundred nine patients with AF/AFL who underwent TEE before pulmonary vein isolation (PVI) or electrical cardioversion for exclusion of LAA sludge or thrombus between January 2010 and December 2014 were retrospectively analyzed. Oral anticoagulant therapy was continued over one month before clinical examination. SEC was defined as dynamic, swirling and smoke-like echoes with optical gain setting during cardiac cycle, and sludge as dynamic gelatinous, precipitous echodensity without a discrete mass at LAA and main cavity during cardiac cycle (grade 3+ or 4+). Results: Mean age was 61±10 years and male was 86 (78.9%). Paroxysmal AF was 64 patients (58.7%), persistent AF was 37 (33.9%) and AFL was 8 (7.3%). Fifty patients (45.9%) were prescribed warfarin. SEC was indicated 14 patients (12.8%), and LAA sludge was 4 in 14 (3.7%). No LAA thrombus was documented. CHA2DS2-VASc score of 4 patients with sludge were 0, 2, 3 and 5, respectively. LAA emptying velocity was reduced in SEC group than non-SEC group (29.1±14.1cm/s vs 44.2±18.0cm/s, p=0.004). The SEC group was significantly different from non-SEC group as follows, 1)higher serum BNP level (174.0±100.9pg/ml vs 83.1±105.3pg/ml, p<0.001), 2)higher serum high-resolution CRP level (0.48±0.68mg/dl vs 0.13±0.27mg/dl, p=0.002), 3)higher serum fibrinogen level (292.7±49.9mg/dl vs 254.9±59.5mg/dl, p=0.046), 4)lower estimated GFR level (60.9±9.1mL/min/1.73m2 vs 69.1±14.4mL/min/1.73m2, p=0.040), 5)fewer patients with paroxysmal AF (6.3% vs 22.2%, p=0.020), 6)more patients with previous heart failure (38.5% vs 9.4%, p=0.012) and 7)poorly LAA contrast enhancement on acute-phase by ECG gated multidetector computed tomography (58.3% vs 5.6%, p<0.001). The LAA morphology and CHA2DS2-VASc score were no significant differences. Among 14 patients with SEC, the patients with sludge were enlarged left atrial volume index (107.1±9.3ml/m2 vs 84.3±7.7ml/m2, p=0.019) and all were used novel oral oral anticoagulants. Conclusion: TEE should undergo for investigation of sludge and thrombus in LAA when SEC was suspected in patients with AF/AFL before PVI or electrical cardioversion. The LAA sludge could not be excluded in spite of CHA2DS2-VASc score of 0. P822 Cardiovasal interconnections depending on Cystatin C in CHF patients with permanent atrial fibrillation J. Nikonova J. Nikonova Medical Academy , Perm , Russian Federation E. Polyanskaya E. Polyanskaya Y. Shilova Y. Shilova N. Koziolova N. Koziolova Abstract Aim: To estimate interconnections between cardiac remodeling and arterial wall parameters depending on renal filtration function according to Cystatin C in ischemic CHF patients with permanent atrial fibrillation Methods and Materials: 60 ischemic CHF and permanent AF patients were examined. Average age was 57,02±5,07 yrs. Average FC of stable angina was 2,51±0,38, average CHF FC was 2,61±0,26. Sphygmoplethismography using VaSera VS-1000 (Fucuda, Japan) was performed to evaluate shock-absorbing and conductive functions of arterial wall. To evaluate systolic function LV EF (Sympson) was estimated using echocardiography. Tissue Doppler imaging of mitral valve annular velocity during passive filling at the septal (septale e') and lateral (laterale e') mitral annulus was used to estimate diastolic function. To evaluate collagen matrix status TIMP-1 was analysed. All patients were divided into 2 groups based on cystatin C level. The 1st group included 25 patients with normal cystatin C level (average mean 783,2±86,5 ng/mL). The 2nd group consisted of 35 patients with elevated cystatin C (average mean 2068,7±223,4 ng/mL), (p<0,001). Results: Carotid-femoral pulse wave velocity (PWVcf) appeared to be significantly higher in the patients of the 1st group that is 11,07±7,06 m/s compared to the patients of the first group that is – 5,84±2,51 m/s (p=0.036). Between the groups significant differences in terms of CAVI1 (p=0.028) were detected. The patients of the first and of the second groups differed significantly in terms of aorta and carotid PWV: 6,72±3,02 vs 9,31±2,07 m/s (p=0.013) and 0,51±0,18 vs 0,72±0,49 m/s (p=0.023) respectively. LVMMI and LV EF did not differ reliably between the groups (p=0,076 N p=0,125, respectively). Septale e' apperaed reliably higher in 2nd group and consisted for 9,24+2,19 cm/sec; N 11,06+3,02 cm/sec (p=0,013), as well as Laterale e': 09,76+2,14 cm/sec and 11,30+1,93 cm/sec, respectively (p=0,005). Mean consisted of 9,37+2,05 cm/sec in 1st, and 11,04+2,08 cm/sec in 2nd group (p=0,003). Ratio E/e' appeared higher in 2nd group than in 1st, p<0,001. Also, reliable direct correlations between cystatin C and TIMP-1 (r=0,67, p=0,046), cystatin C and CAVI1 (r=0,76, p=0,032), cystatin C and PWVcf (r=0,56, p=0,002), cystatin C and Septale e' (r=0,53, p=0,011) were revealed. Conclusions: In ischemic CHF patients with permanent AF there is an elevation of stiffness of cardiovasal contour, which is showed in disorder of myocardial relaxation and increase in arterial wall stiffnes and decrease of its elasticity along with decrease of renal filtration function by Cystatin C. P823 Association between red blood cell distribution width and postoperative atrial fibrillation after cardiac surgery: a prospective observational study E. Apostolakis E. Apostolakis 3 University of Ioannina Medical School, Department of Cardiothoracic Surgery , Ioannina , Greece S. Siminelakis S. Siminelakis 3 University of Ioannina Medical School, Department of Cardiothoracic Surgery , Ioannina , Greece T. Liu T. Liu 2 2nd Hospital of Tianjin Medical University, Departmet of Cardiology , Tianjin , China, People's Republic of N. Sontis N. Sontis 1 University of Ioannina Medical School, Department of Cardiology , Ioannina , Greece P. Korantzopoulos P. Korantzopoulos 1 University of Ioannina Medical School, Department of Cardiology , Ioannina , Greece Abstract Purpose: Postoperative atrial fibrillation (POAF) is the most common complication after cardiac surgery with a significant impact on morbidity and mortality. Red blood cell distribution width (RDW) may reflect inflammation and oxidative stress and has been associated with AF. Our aim was to prospectively evaluate the potential association of RDW with POAF. Methods: 109 patients (79 men, age: 66.9±9.5 years) undergoing elective on-pump cardiac surgery were studied. Baseline demographic, clinical, echocardiographic, and laboratory parameters were carefully recorded. Conventional inflammatory indexes were also assessed. Multivariate analysis and ROC curve analysis for parameters associated with POAF was performed. Results: Forty four patients (44.4%) patients developed POAF. The multivariate logistic regression analysis showed that RDW was the only independent predictor of POAF (OR: 1.46; 95% CI: 1.078-1.994; p=0.015). The ROC curve analysis showed that the area under the curve was 0.70 (p=0.001). A RDW cut-off point of 13.35 was related to POAF with a sensitivity of 80% and a specificity of 60%. Conclusions: Baseline RDW levels are associated with the occurrence of POAF after elective cardiac surgery and seem to be a useful prognostic index in this setting. P824 No efficacy of antiarrhythmic drugs during the first 3-months after pulmonary vein isolation in patients with paroxysmal atrial fibrillation H. Okamura H. Okamura T. Noda T. Noda T. Aiba T. Aiba S. Kamakura S. Kamakura K. Kusano K. Kusano National Cerebral and Cardiovascular Center, Division of Cardiology , Suita , Japan K. Ishibashi K. Ishibashi I. Nakajima I. Nakajima M. Wada M. Wada K. Miyamoto K. Miyamoto S. Hirose S. Hirose Abstract Background: Pulmonary vein isolation (PVI) is an effective treatment for patients with paroxysmal atrial fibrillation (PAF). Several studies, however, reported that patient with early atrial fibrillation recurrence (EAFR) during the first 3-months after PVI had a higher rate of late AF recurrence (LAFR) than those without EAFR. The efficacy of antiarrhythmic drug (AAD) during blanking period (the first 3-months after PVI) for prevention of AF recurrence is unknown in patients undergoing PVI. Methods and Results: A total of 208 patients with PAF (151 males, age 65 ± 11 years, mean follow-up 483 ± 278 days) underwent their first PVI of AF in our institute. Eleven patients had congenital heart disease, 12 patients valve disease, 8 patients hypertrophic cardiomyopathy, 10 patients ischemic disease, and one patient dilated cardiomyopathy. We investigated the efficacy of AAD for AF prevention in patients with EAFR (98 patients, 66 with AAD [classIII 32, classI 34]) and those without EAFR (109 patients, 47 with AAD [classIII 20, classI 27]). There are no significant differences between patients with and without EAFR in left atrial dimension (40±6.5 vs 39±6.3 mm, respectively, p = 0.25) and left ventricular ejection fraction (58±7.8 vs 58±7.5 %, respectively, p = 0.80). Figure shows the freedom rate from LAFR in each patient population. There was no significant difference in LAFR between patients with and without AAD in each patient population. There was no significant difference in AF recurrence rate between two AADs in each patient population. Conclusions: AAD didn't have clinical significance for AF prevention regardless of EAFR after PVI. P825 Is CHA2DS2-VASc score predictive of long-term outcome of catheter ablation of atrial fibrillation evaluated with implantable ECG loop recorder? A. Vachulova A. Vachulova H. Cerna H. Cerna L. Urban L. Urban P. Hlivak P. Hlivak M. Svetlosak M. Svetlosak P. Margitfalvi P. Margitfalvi M. Sasov M. Sasov K. Gladisova K. Gladisova V. Bernat V. Bernat R. Hatala R. Hatala Clinic of Cardiology SZU and NUSCH a.s. , Bratislava , Slovak Republic Abstract Catheter ablation of atrial fibrillation (CAAF) is an effective interventional therapy for highly symptomatic patients with paroxysmal / persistent AF. This prospective study aimed to analyse the predictive value of CHA2DS2-VASc score on the outcome of CAAF. The outcome of the intervention was evaluated by means of an implantable ECG loop recorder and expressed as the overall AF burden in the post-ablation period (defined as the relative amount of time spent in AF). Patients and Methods: We retrospectively analysed 133 patients (108 males - 81%), mean age 55±9 years with paroxysmal/persistent AF who underwent CA AF during 2005-2013 and were monitored with an implantable ECG loop recorder (REVEAL XT, Medtronic Inc., USA). Complete pulmonary vein isolation was the endpoint of all procedures. The initial 3 months post CA AF were not included in the ECG follow-up (blanking period). Results: Mean overall AF burden prior to CA AF was 21.7 ± 17.9 %. During the 12 -15 months follow-up after CAAF it decreased to 5.1 ± 12.5% (p < 0.01). The maximal statistically significant AF burden reduction was observed 9 month after CAAF. The achieved reduction of AF burden was not related to the value of pre-ablation CHA2DS2-VASc score. Conclusions: Accumulation of risk factors as expressed in the CHA2DS2-VASc score reflects overall cardiovascular morbidity of the patient. Our analysis suggests that higher levels of baseline morbidity as expressed by higher CHA2DS2-VASc score are not predictive of reduced efficacy of catheter ablation of paroxysmal / persistent AF. Table 1 AF burden reduction after CA AF CHA2DS2-VASc score AF burden before CA AF (%) AF burden 12 -15 months after CA AF (%) Relative reduction of AF burden (%) P value 0 26.08 ± 19.6 6.11±11.4 76.6 p < 0.01 1 20.43± 17.3 5.45 ± 13.9 73.3 p < 0.01 2 27.96± 20.9 4.90 ± 14.3 82.47 p < 0.001 ≥3 15.39 ± 14.1 3.21 ±6.03 79.14 p < 0.01  CHA2DS2-VASc score AF burden before CA AF (%) AF burden 12 -15 months after CA AF (%) Relative reduction of AF burden (%) P value 0 26.08 ± 19.6 6.11±11.4 76.6 p < 0.01 1 20.43± 17.3 5.45 ± 13.9 73.3 p < 0.01 2 27.96± 20.9 4.90 ± 14.3 82.47 p < 0.001 ≥3 15.39 ± 14.1 3.21 ±6.03 79.14 p < 0.01  Table 1 AF burden reduction after CA AF CHA2DS2-VASc score AF burden before CA AF (%) AF burden 12 -15 months after CA AF (%) Relative reduction of AF burden (%) P value 0 26.08 ± 19.6 6.11±11.4 76.6 p < 0.01 1 20.43± 17.3 5.45 ± 13.9 73.3 p < 0.01 2 27.96± 20.9 4.90 ± 14.3 82.47 p < 0.001 ≥3 15.39 ± 14.1 3.21 ±6.03 79.14 p < 0.01  CHA2DS2-VASc score AF burden before CA AF (%) AF burden 12 -15 months after CA AF (%) Relative reduction of AF burden (%) P value 0 26.08 ± 19.6 6.11±11.4 76.6 p < 0.01 1 20.43± 17.3 5.45 ± 13.9 73.3 p < 0.01 2 27.96± 20.9 4.90 ± 14.3 82.47 p < 0.001 ≥3 15.39 ± 14.1 3.21 ±6.03 79.14 p < 0.01  P826 Non-fluoroscopic sensor-based catheter navigation in ablation of atrial fibrillation: a randomized comparison with electroanatomic standard procedures S. Rolf S. Rolf 1 University of Leipzig, Heart Center, Department of Electrophysiology , Leipzig , Germany K. Schoene K. Schoene 1 University of Leipzig, Heart Center, Department of Electrophysiology , Leipzig , Germany S. Richter S. Richter 1 University of Leipzig, Heart Center, Department of Electrophysiology , Leipzig , Germany C. Piorkowski C. Piorkowski 2 University of Dresden, Heart Center, Department of Electrophysiology , Dresden , Germany T. Gaspar T. Gaspar 2 University of Dresden, Heart Center, Department of Electrophysiology , Dresden , Germany Y. Huo Y. Huo 2 University of Dresden, Heart Center, Department of Electrophysiology , Dresden , Germany A. Arya A. Arya 1 University of Leipzig, Heart Center, Department of Electrophysiology , Leipzig , Germany A. Bollmann A. Bollmann 1 University of Leipzig, Heart Center, Department of Electrophysiology , Leipzig , Germany G. Hindricks G. Hindricks 1 University of Leipzig, Heart Center, Department of Electrophysiology , Leipzig , Germany P. Sommer P. Sommer 1 University of Leipzig, Heart Center, Department of Electrophysiology , Leipzig , Germany Abstract Purpose: A novel platform for nonfluorososcopic sensor tracking (NFST) within precorded x-ray loops has been introduced. Its application in the context of catheter ablation of atrial fibrillation (AF) indicated significant potential for reduction of fluoroscopy. Randomized comparisons with established electroanatomic technologies are lacking. Methods: Patients with AF were randomized into two groups before scheduled radiofrequency ablation: (1) catheter navigation using NFST together with established mapping systems and fluoroscopy, (2) control group with standard electroanatomic mapping system and fluoroscopy alone. Procedures were performed in the same lab by 2 experienced operators altogether. Moreover, the same strategies (circumferential pulmonary vein isolation followed by voltage mapping ± targeted substrate modification) and ablation catheters were applied. Results: A total of 80 patients (48 men, mean age 60 years, 44 patients with paroxysmal AF) were equally randomized into both groups. Clinical parameters between both groups were similar. Procedural parameters and 6-months follow-up data (from 52 patients so far) can be derived from table. Conclusion: Radiation exposure can be significantly reduced to a minimum by using the novel NFST technology in addition to standard AF ablation technologies, without negative consequences on procedure duration, complication rate, or clinical outcome. Abandonment of additional fluoroscopy use allowing for working without lead protections following transseptal puncture is possible. Procedural and Outcome Data  NFST group Control group p-value Fluoroscopy time (min) 3±3 14±6 <0.001 Fluoroscopy dose (Gycm2) 687±665 1899±1396 <0.001 Procedure duration (min) 136±43 138±38 0.84 Radiofrequency time (min) 38±16 39±19 0.80 Add. substrate modification 6 (15%) 9 (23%) 0.57 Periprocedural complications 0 (0%) 0 (0%) 1.00 Recurrent atrial tachycardias 8/30 (27%) 4/22 (18%) 0.53   NFST group Control group p-value Fluoroscopy time (min) 3±3 14±6 <0.001 Fluoroscopy dose (Gycm2) 687±665 1899±1396 <0.001 Procedure duration (min) 136±43 138±38 0.84 Radiofrequency time (min) 38±16 39±19 0.80 Add. substrate modification 6 (15%) 9 (23%) 0.57 Periprocedural complications 0 (0%) 0 (0%) 1.00 Recurrent atrial tachycardias 8/30 (27%) 4/22 (18%) 0.53  Procedural and Outcome Data  NFST group Control group p-value Fluoroscopy time (min) 3±3 14±6 <0.001 Fluoroscopy dose (Gycm2) 687±665 1899±1396 <0.001 Procedure duration (min) 136±43 138±38 0.84 Radiofrequency time (min) 38±16 39±19 0.80 Add. substrate modification 6 (15%) 9 (23%) 0.57 Periprocedural complications 0 (0%) 0 (0%) 1.00 Recurrent atrial tachycardias 8/30 (27%) 4/22 (18%) 0.53   NFST group Control group p-value Fluoroscopy time (min) 3±3 14±6 <0.001 Fluoroscopy dose (Gycm2) 687±665 1899±1396 <0.001 Procedure duration (min) 136±43 138±38 0.84 Radiofrequency time (min) 38±16 39±19 0.80 Add. substrate modification 6 (15%) 9 (23%) 0.57 Periprocedural complications 0 (0%) 0 (0%) 1.00 Recurrent atrial tachycardias 8/30 (27%) 4/22 (18%) 0.53  P827 Totally nonfluoroscopic atrial fibrillation ablation approach. Single centre experience E. Kropotkin E. Kropotkin E.A. Ivanitskiy E.A. Ivanitskiy Federal Centre of Cardiovascular Surgery , Krasnoyarsk , Russian Federation Abstract Purpose: To compare safety and effectiveness of routine fluoroscopic and nonfluoroscopic approach of catheter ablation of atrial fibrillation (AF). Method: totally nonfluoroscopic approach for atrial fibrillation ablation was developed in our center. 3D navigation system and catheter with contact force control capabilities were utilized for these purposes. Intracardiac echo (ICE) was used to visualize anatomy of the heart and catheters inside the cardiac chambers. Double transseptal punctures for Lasso guided ablation were performed under ICE control. Ablation parameters were the same for both groups (430, 29W, 60 sec. per point). We prospectively enrolled 230 patients who were randomized into two groups: 113 - to nonfluoro approach, 117 - to routine one. Mean procedure time of nonfluoroscopic 135+47 min., for routine 147+ 42 min. Results: Antral pulmonary vein isolation was achieved in 100% in the first group. In the second group 8 veins were isolated separately 6 - right sided, 2 left sided. One pericardial effusion in the first group was treated by pericardial drainage. One transient ischemic attack in the second group fully resolved within four days. Thrombous formation on catheters was revealed in four cases in the first group, in one case only system thrombolysis was utilized due to size of thrombotic mass on Lasso catheter. Conclusion: Totally nonfluoroscopic approach for catheter ablation of AF is safe and could be widely used to reduce detrimental effect of fluoroscopy on both physician and patient. Effectiveness and procedure duration were comparable for both groups. P828 Decrease in asymptomatic cerebral lesions during left atrial ablation due to improved workflow: a single center comparison M. Derndorfer M. Derndorfer 1 Elisabethinen University Teaching Hospital, Department of Cardiology , Linz , Austria E. Sigmund E. Sigmund 1 Elisabethinen University Teaching Hospital, Department of Cardiology , Linz , Austria S. Winter S. Winter 1 Elisabethinen University Teaching Hospital, Department of Cardiology , Linz , Austria W. Jauker W. Jauker 2 Elisabethinen University Teaching Hospital, Department of Radiology , Linz , Austria M. Gschwendtner M. Gschwendtner 2 Elisabethinen University Teaching Hospital, Department of Radiology , Linz , Austria J. Aichinger J. Aichinger 1 Elisabethinen University Teaching Hospital, Department of Cardiology , Linz , Austria H. Puererfellner H. Puererfellner 1 Elisabethinen University Teaching Hospital, Department of Cardiology , Linz , Austria M. Martinek M. Martinek 1 Elisabethinen University Teaching Hospital, Department of Cardiology , Linz , Austria Abstract Aims: Left atrial radiofrequency ablation during pulmonary vein isolation (PVI) has been associated with an increased risk of asymptomatic cerebral lesions. Uninterrupted oral anticoagulation (OAC) alone during procedures has not been able to completely prevent cerebral embolism. We compared silent cerebral lesions in a group with an improved workflow during PVI ("new protocol") to standard ablation ("standard"). For both groups uninterrupted OAC was obligatory. Cerebral lesions were assessed by pre- and post-procedural magnetic resonance imaging (MRI). Methods and results: A total of 220 consecutive patients (110 each group) with catheter ablation for paroxysmal or persistent atrial fibrillation were included. In standard procedures two initial boluses of i.v. unfractionated heparin (UFH) were administered: A first "small" bolus of 3.000 – 5.000 IU before transseptal puncture (TSP), and a second bolus to add up to 100 IU/kg body weight after TSP. The new protocol consisted of a "full" initial bolus of i.v. UFH (100 IU/kg body weight) after groin venous puncture to maximize anticoagulation during TSP and modified catheter management leaving blood backflow from transseptal sheaths during catheter insertion to prevent air-intake. Activated clotting time was 300 to 400 s in both groups (continuous i.v. UFH+boluses). Post-procedural MRI showed a trend to less cerebral lesions with the new protocol (standard: 12.7%, new protocol: 5.5%, p= 0.061, Fig. 1). No severe complications occured (death, haemopericardium, severe bleeding, neurological deficit) Conclusions: The new workflow-protocol during PVI shows a decrease in asymptomatic cerebral lesions. Whether this is an effect of the full-dose heparin protocol prior to TSP or due to modified catheter-handling should be point of further investigation. Fig.1 P829 Stiffening of the left atrium immediately after pulmonary vein isolation R. Pap R. Pap G. Agoston G. Agoston J. Szilagyi J. Szilagyi G. Bencsik G. Bencsik G. Klausz G. Klausz L. Saghy L. Saghy A. Varga A. Varga T. Forster T. Forster Albert Szent-Gyorgyi/Univ. of Szeged, Faculty Medical, 2nd Dpt of Internal Med. & Cardiology Center , Szeged , Hungary Abstract Introduction: The stiff left atrial (LA) syndrome is defined as symptomatic pulmonary hypertension secondary to reduced LA compliance and has recently been recognized as a complication of pulmonary vein isolation (PVI) for atrial fibrillation (AF). We investigated acute changes in LA stiffness immediately after PVI. Methods: Sixteen patients (5 female, age: 60±9 years) undergoing their first PVI for paroxysmal AF were included. Transthoracic echocardiography was carried out immediately before and after creation of wide, circumferential PVI lesions using irrigated, point-by-point radiofrequency ablation. Peak atrial longitudinal strain (PALS) and peak atrial contraction strain (PACS) of the LA, along with left ventricular diastolic function was assessed simultaneously with invasive LA pressure recording. Reservoir phase LA stiffness index was calculated as PALS / mean LA pressure. Results: Peak and mean LA pressure increased from before to immediately after PVI (from 16.6±10.0 to 21.0±9.4 mmHg, p=0.02 and from 6.0±5.5 to 8.2±5.1 mmHg, p=0.05, respectively). At the same time LA strain tended to decrease (PALS: from 15.2±4.7 to 13.3±4.3 %, p=0.08, PACS: from 8.5±2.9 to 6.0±2.9 %, p=0.01) and stiffness index increased (from 0.48±0.78 to 0.76±0.90, p=0.02). There was no change in left ventricular diastolic parameters. Conclusions: Left atrial catheter ablation to achieve PVI results in an immediate increase in LA stiffness, unrelated to left ventricular diastolic function. This may be a harbinger of later stiff LA syndrome. P830 Spatial relationship of focal impulses, rotors and low voltage zones in patients with persistent atrial fibrillation A. Schade A. Schade 1 Helios Clinic Erfurt, Electrophysiology , Erfurt , Germany P. Mueller P. Mueller 2 Heart and Vascular Hospital , Bad Neustadt/ Saale , Germany P. Halbfass P. Halbfass 2 Heart and Vascular Hospital , Bad Neustadt/ Saale , Germany M. Roos M. Roos 2 Heart and Vascular Hospital , Bad Neustadt/ Saale , Germany K. Nentwich K. Nentwich 2 Heart and Vascular Hospital , Bad Neustadt/ Saale , Germany G.A. Szoelloesi G.A. Szoelloesi 2 Heart and Vascular Hospital , Bad Neustadt/ Saale , Germany L.C. Costello-Boerrigter L.C. Costello-Boerrigter 1 Helios Clinic Erfurt, Electrophysiology , Erfurt , Germany T. Deneke T. Deneke 2 Heart and Vascular Hospital , Bad Neustadt/ Saale , Germany Abstract Introduction: Focal impulses and rotational activity have been related to occurrence and maintenance of AF and ablation of these sources leads to AF termination and prevention of recurrences. Atrial low voltage zones (LVZ) representing fibrosis are associated to a higher incidence and higher recurrence rates of AF. The aim of the study was to characterize the relation between focal and rotational sources of AF and atrial LVZ. Methods: In patients (pt) with persistent (pers) AF, focal impulses and rotors were mapped and ablated. Voltage map of both atria was done during AF (< 0.5 mV regarded as LVZ) using EnSite™ NavX™ (St. Jude). Endocardial source mapping using RhythmViewTM (Topera Inc) followed. Basket catheter was placed in complementary positions in case of insufficient LA or RA covering. Endocardial surface area of RA and LA, size and percentage of LVZ areas in RA and LA and the number and localization of sources were determined. Results: In the study, 24 pt undergoing their first ablation for pers AF (6/24 (25%) long pers, mean age 61 ±11 years, 17/24 (71%) male) were included. LVZ covered 13±12% of RA endocardial surface and 33 ±25% of LA endocardial surface. LA showed large LVZ (≥30%) in 12 of 21 pt (57%). Median number of sources per patient in RA was 1 [1-3], and 3 [1-4] in LA. Rate of RA rotors correlated with RA size (r= 0.513; p 0.018). In the RA only 1/37 (3% of) sources were located within a LVZ, whereas 5/37 (14%) were adjacent to a LVZ. Of the 37 RA sources 31 (83%) were found remote of LVZ. Of the 59 sources mapped in LA 23 (39%) were localized within LVZ, 12 (20%) adjacent to LVZ, and 24 (41%) remote of LVZ, 10 (17%) were detected within a typical circumferential PVI line. Altogether 16 (27%) of LA sources are not associated to LVZ or pulmonary veins. During ablation of rotors significant AF CL prolongation (at least 10%) was observed in 10/22 (45%) of patients. In two of the patients (9%) AF converted to a regular AT, and in one pt (5%) to sinus rhythm. Of the 11 cases of CL prolongation or AF termination 6 occurred during ablation in RA (55%) and 5 (45%) in LA. In most pt these sites (8 (73%)) were observed during ablation of sources remote of LVZ. Conclusions: LVZ are rare and small in RA, but common in LA of pers AF cases. RA sources have no relation to LVZs. In LA 2/3 of sources are located in or adjacent to LVZs or within PV. CL prolongation or regularization occurred mostly remote of PVs and LVZ in in the RA and LA. This finding suggests, that targeting focal impulses and rotors may focus on LA and RA areas different from PVI and LVZ. P831 Impact of esophageal temperature monitoring-guided ablation during pulmonary vein isolation on pulmonary vein reconnection M. Pedersen M. Pedersen K. Rajappan K. Rajappan M. Ginks M. Ginks Y. Bashir Y. Bashir T.R. Betts T.R. Betts Oxford University Hospitals NHS Trust , Oxford , United Kingdom M. Leo M. Leo Abstract Purpose: To investigate if esophageal temperature monitoring during pulmonary vein isolation, with temperature alerts leading to early termination of radiofrequency (RF) and/or reduction in power, prevents lesion durability and promotes acute and chronic pulmonary vein reconnection (PVR). Methods: At our institution the luminal esophageal temperature is continuously monitored during all AF ablations using the SensiTherm probe (St Jude Medical). There are 3 thermocouples that can be also visualised on the Velocity LA geometry. Any sites that cause a temperature rise of >39°C, with premature cessation of RF and/or reduction in power to 20-25W during wide area encirclement, are labelled on the geometry in a different colour from standard, complete and uninterrupted RF lesions (30-40W, minimum 15-20 seconds in a stable position). The study population consisted of all patients returning for a 1st redo ablation from November 2012 to May 2014. The sites of acute PVR at the time of the index procedure and chronic PVR at the time of the redo procedure (determined by multipolar catheter mapping) and the sites of successful re-isolation were labelled on the 3D geometry and compared with prior lesion markers for temperature alerts from the index procedure. Results: Fifty-four patients underwent redo procedures (36 male, age 68±8, 59% persistent AF). Forty-six PVs (21% of a total of 216 PVs) in 30 patients (56%) had at least one temperature alert during the index procedure. The median length of lesions causing alerts was 21 (16-26) mm for LPVs and 18 (15-25) mm for RPVs. The distribution of temperature alerts at the initial procedure was LSPV 24%, LIPV 33%, RSPV 13% and RIPV 31% (p=0.9). Despite the presence of temperature alerts, PV isolation was achieved in all PVs. Acute PVR, requiring further ablation at the index procedure, occurred in 23 PVs in 12 patients. Chronic PVR was seen in 103 PVs from 44 patients at the redo procedure. No correlation was found between temperature alerts at the index procedure and acute or chronic PVR in the associated PV (p=0.51 and p=0.27 respectively). Conclusions: Just over half of patients undergoing PV isolation will have an esophageal temperature alert. Reducing power and RF duration does not increase or decrease the incidence of subsequent PV reconnection. Esophageal temperature probe-guided ablation may therefore increase safety without compromising ablation efficacy. P832 Effect of arrhythmia burden and arrhythmia-related events on quality of life in patients undergoing ablation for atrial fibrillation: a substudy of the AMIO-CAT trial S. Darkner S. Darkner 1 Rigshospitalet - Copenhagen University Hospital, Heart Centre, Cardiac Catheterization Laboratory , Copenhagen , Denmark X. Chen X. Chen 1 Rigshospitalet - Copenhagen University Hospital, Heart Centre, Cardiac Catheterization Laboratory , Copenhagen , Denmark J. Hansen J. Hansen 2 Gentofte University Hospital , Copenhagen , Denmark S. Pehrson S. Pehrson 1 Rigshospitalet - Copenhagen University Hospital, Heart Centre, Cardiac Catheterization Laboratory , Copenhagen , Denmark A. Johannessen A. Johannessen 2 Gentofte University Hospital , Copenhagen , Denmark J.H. Svendsen J.H. Svendsen 1 Rigshospitalet - Copenhagen University Hospital, Heart Centre, Cardiac Catheterization Laboratory , Copenhagen , Denmark Abstract Background: Catheter ablation of atrial fibrillation (AF) aims to relieve patients' symptoms and improve quality of life (QoL). However, the effect of AF burden on QoL is still unresolved. In this substudy of the AMIO-CAT trial, we aimed to investigate the effect of arrhythmia burden and arrhythmia related events on QoL in patients undergoing catheter ablation for AF. Method: The AMIO-CAT trial randomised a total of 212 patients undergoing catheter ablation for paroxysmal (n=107) or persistent (n=105) AF to 8 weeks of post ablation oral amiodarone therapy or matched placebo in a double-blind design. Patients were followed for a total of 6 months post ablation. Three-day Holter-monitorings and QoL assessment by Short-Form Health Survey (SF-36) questionnaires were performed prior to ablation and at 6-8 weeks and 6 months post ablation. Results: Patients with higher percentage of AF burden had lower QoL scores at baseline, at 6-8 weeks and at 6 months post ablation and relative changes in AF burden from baseline were inversely correlated with changes in QoL scores throughout the study. Patients with AF-related hospitalizations or cardioversions within the 3-months blanking period and patients with documented recurrence at 6-months follow-up had significantly lower QoL compared to those without. Conclusion: Arrhythmia burden and relative changes in AF burden as measured by Holter monitoring were inversely associated with patients QoL scores. Moreover, arrhythmia-related events during blanking period and documented recurrence at 6-months follow-up were associated with lower QoL scores. This suggests that not necessarily complete AF-abolishment but even a reduction of arrhythmia burden by catheter ablation will improve QoL in patients with symptomatic paroxysmal or persistent AF. P833 Is combined ablation for paroxysmal atrial fibrillation using balloon cryoablation and radiofrequency ablation superior to either technique alone? Long-term follow up and cost analysis R. Ang R. Ang Clinical Research Unit, St Bartholomew's Hospital, London Clinical Research Unit, St Bartholomew's Hospital, London M. Finlay M. Finlay Clinical Research Unit, St Bartholomew's Hospital, London Clinical Research Unit, St Bartholomew's Hospital, London M. Dhinoja M. Dhinoja Clinical Research Unit, St Bartholomew's Hospital, London Clinical Research Unit, St Bartholomew's Hospital, London M. Earley M. Earley Clinical Research Unit, St Bartholomew's Hospital, London Clinical Research Unit, St Bartholomew's Hospital, London R. Schilling R. Schilling Clinical Research Unit, St Bartholomew's Hospital, London Clinical Research Unit, St Bartholomew's Hospital, London R. Hunter R. Hunter Clinical Research Unit, St Bartholomew's Hospital, London Clinical Research Unit, St Bartholomew's Hospital, London S. Sporton S. Sporton St Bartholomew's Hospital, Cardiology , London , United Kingdom Clinical Research Unit, St Bartholomew's Hospital, London Clinical Research Unit, St Bartholomew's Hospital, London A. Opel A. Opel Clinical Research Unit, St Bartholomew's Hospital, London Clinical Research Unit, St Bartholomew's Hospital, London M.A. Akhtar M.A. Akhtar Clinical Research Unit, St Bartholomew's Hospital, London Clinical Research Unit, St Bartholomew's Hospital, London S. Hadjivassilev S. Hadjivassilev Clinical Research Unit, St Bartholomew's Hospital, London Clinical Research Unit, St Bartholomew's Hospital, London Abstract Introduction: Our CRYO versus RF trial demonstrated that at 12 months, catheter ablation for paroxysmal atrial fibrillation (pAF) using balloon cryoablation (CRYO) had a higher single procedure success rate than radiofrequency ablation (RF) wide area circumferential ablation. A combined approach with RF and CRYO was superior to RF but not to CRYO alone. We present long-term follow up, together with a cost analysis. Methods: Patients with drug-refractory symptomatic pAF were randomly assigned to receive CRYO, RF or the combination of both. Repeat procedures were performed using RF. Follow up data to April 2014 were collected from electronic patient records. In addition, each patient received a telephone call to document further symptoms. Success was defined as freedom from symptomatic AF, off all antiarrhythmic drugs. Overall procedural cost was calculated as cost of index procedure+(% of patients requiring repeat procedure x cost of RF procedure). Data were analysed on an intention-to-treat basis. Results: 244 patients were included. Follow up ranged from 16 to 66 (median 39) months overall: 16 to 61 for CRYO (median 38), 17 to 66 (median 39) for RF and 17 to 57 (median 39) for combined. Please see table. * p=0.27 vs. RF alone ** p<0.01 vs. Combined *** p=0.025 vs. CRYO + p=1.00 vs. RF alone ++ p=0.37 vs. Combined +++ p=0.37 vs. CRYO Conclusions: Although a combined index procedure has a higher initial cost than either single procedure, this was offset by the fewer procedures and recurrences. Fewer total procedures were maintained by the CRYO group over the RF group, and the lowest overall cost was achieved by CRYO over the other two groups.  No. of patients Success after single procedure (%) Success at latest follow-up (%) Mean no. procedures per patient at latest follow-up Cost of index procedure (GBP) Overall procedural cost per patient(GBP) CRYO alone 81 52* 84+ 1.48 8615 12629 RF alone 81 42** 84++ 1.74 8362 14550 Combined 82 70*** 89+++ 1.21 11112 12868   No. of patients Success after single procedure (%) Success at latest follow-up (%) Mean no. procedures per patient at latest follow-up Cost of index procedure (GBP) Overall procedural cost per patient(GBP) CRYO alone 81 52* 84+ 1.48 8615 12629 RF alone 81 42** 84++ 1.74 8362 14550 Combined 82 70*** 89+++ 1.21 11112 12868  Success and cost of each treatment modality  No. of patients Success after single procedure (%) Success at latest follow-up (%) Mean no. procedures per patient at latest follow-up Cost of index procedure (GBP) Overall procedural cost per patient(GBP) CRYO alone 81 52* 84+ 1.48 8615 12629 RF alone 81 42** 84++ 1.74 8362 14550 Combined 82 70*** 89+++ 1.21 11112 12868   No. of patients Success after single procedure (%) Success at latest follow-up (%) Mean no. procedures per patient at latest follow-up Cost of index procedure (GBP) Overall procedural cost per patient(GBP) CRYO alone 81 52* 84+ 1.48 8615 12629 RF alone 81 42** 84++ 1.74 8362 14550 Combined 82 70*** 89+++ 1.21 11112 12868  Success and cost of each treatment modality P834 Catheter ablation for paroxysmal atrial fibrillation improves sleep-disordered breathing S. Mito S. Mito Y. Muraoka Y. Muraoka N. Shiode N. Shiode Akane Foundation Tsuchiya General Hospital , Hiroshima , Japan Abstract Introduction: Obstructive sleep apnea was shown to be independently associated with an increased risk of atrial fibrillation. We investigated the efficacy of ganglionated plexus (GP) ablation and circumferential pulmonary vein ablation in patients with sleep apnea syndrome (SAS) and paroxysmal atrial fibrillation (AF). Methods: A total of 25 patients (male/female=22/3, 68±8 years) with SAS who underwent RFCA for paroxysmal AF were studied. RF was delivered after all GP sites had been identified in the left atrium and after that extensive pulmonary vein isolation was performed in all patients. Polysomnography was also performed 1 day before and three to five days after RFCA to evaluate the effect of RFCA on sleep-disordered breathing in all patients. Results: RFCA was successfully performed in all patients. Heart rate variability parameters showed significant changes after RFCA (SDNN: baseline 121.3±35.1 ms, after RFCA 94.1±28.9 ms, P<0.01, rMSSD: baseline 44.2±34.3 ms, after RFCA 22.0±18.0 ms, P<0.01, HR: baseline 61.7±8.7, after RFCA 68.8±9.6, P<0.0001). At the same time, the apnea-hypopnea index (AHI) decreased significantly after RFCA (baseline 28.7±13.9, after RFCA 20.7±13.2, P<0.0001). Conclusion: RFCA for paroxysmal AF decreased AHI. Neural ablation may contribute to improve sleep-disordered breathing. P835 Catheter ablation of paroxysmal and persistent atrial fibrillation: long-term outcome of a pulmonary vein isolation-based strategy as index procedure B. Valente B. Valente T. Silva T. Silva A. Monteiro A. Monteiro R. Pimenta R. Pimenta A.S. Delgado A.S. Delgado R.C. Ferreira R.C. Ferreira Hospital Santa Marta, CHLC , Lisbon , Portugal M.M. Oliveira M.M. Oliveira M.N. Silva M.N. Silva P.S. Cunha P.S. Cunha A. Lousinha A. Lousinha Abstract Pulmonary veins (PV) isolation (PVI) has been accepted as the strategy of choice for ablation of paroxysmal atrial fibrillation (AF). However, around 25% of AF ablations are performed in patients (P) with persistent AF (PersAF). Moreover, the results of the different ablation approaches using extensive linear lesions for the treatment of PersAF remain controversial, with PVI being the cornerstone of the intervention procedure. Aim: to examine the long-term results of catheter ablation for paroxysmal (PAF) or PersAF using an antral PVI-based approach. Methods: 124P with PAF (group A, n=91; 58,2% men; 51,4±11 years) or PersAF (group B, n=33; 78,7% men; 51,3±12 years; mean duration of AF - 5 months), without other documented arrhythmias, submitted to PVI alone, with at least 12 months follow-up. Underlying heart diseases were present in 25,8% of the P (hypertension, dilated or hypertrophic cardiomyopathy, corrected congenital heart disease). Antral PVI ablation was guided by a circular multipolar catheter combined with 3D electroanatomic mapping (Ensite NavX or Carto) integrated with multislice CT imaging. Those cases without conversion to sinus rhythm (SR) after PVI proceeded to external electrical cardioversion. Results: left ventricular ejection fraction ranged between 26% and 60% (50±8%), the left atrium measured 45±8 mm (M-mode), with a volume of 100±35 ml (group A vs. group B, p=NS). All P were discharged in SR under antiarrhythmic drugs (AA). Anticoagulant therapy and AA were maintained for at least 6 months. The follow-up protocol included event recorders (1st month), repeated ECGs and Holter monitoring. There were no significant differences in clinical characteristics between groups. Procedure duration, fluoroscopy time and radiofrequency applications duration were 150±37 min, 24±9 min and 31±15 min, respectively for PAF, and 151±35 mn, 24,2±9,0 mn and 35±15 mn, respectively, for PersAF (PAF vs. PersAF, p=NS). There were 5 cardiac tamponades (4%). During the first 14 months, AF recurrences occurred in 13% of PAF cases and in 27% of PersAF P (p=0.05). There were 9 redos (10%) in group A and 4 (12%) in group B (p=NS). Conclusion: A simplified antral PVI-based strategy as index approach is associated with good outcomes in PAF and PersAF, but with superior long-term success rates in PAF. P836 Low vulnerability of the right phrenic nerve for electroporation ablation K.G.E.J. Neven K.G.E.J. Neven 1 University Medical Center Utrecht, Department of Cardiology , Utrecht , Netherlands V.J.H.M. Van Driel V.J.H.M. Van Driel 1 University Medical Center Utrecht, Department of Cardiology , Utrecht , Netherlands H. Van Wessel H. Van Wessel 1 University Medical Center Utrecht, Department of Cardiology , Utrecht , Netherlands A. Vink A. Vink 2 University Medical Center Utrecht, Department of Pathology , Utrecht , Netherlands P.A.F.M. Doevendans P.A.F.M. Doevendans 1 University Medical Center Utrecht, Department of Cardiology , Utrecht , Netherlands F.H.M. Wittkampf F.H.M. Wittkampf 1 University Medical Center Utrecht, Department of Cardiology , Utrecht , Netherlands Abstract Introduction: Circular irreversible electroporation is a novel, non-thermal ablation modality for pulmonary vein isolation. A single 200 J application can create a deep myocardial lesion. Acute and chronic effects of this new energy source on the right phrenic nerve (PN) are unknown. Methods: Nerve vulnerability to irreversible electroporation was studied in a porcine model. In 20 animals (60-75 kg), the course of the right PN was pacemapped inside the superior caval vein (SCV). In 19 of 20 animals, the PN could be captured along an 6-8 cm trajectory above the right atrial contour. In these animals, a single 200 J circular electroporation ablation was performed via a multipolar circular catheter in firm contact with the SCV wall (Fig. A). Results: Directly after ablation, the PN could be captured above the ablation level in 17 of 19 animals, and after maximally 30 minutes in all. Fifteen animals were restudied after 3 to 13 weeks and PN functionality was unaffected in all. Histological analysis in 5 animals, in which the application had been delivered in the muscular sleeve just above the right atrium, showed a transmural circular lesion (Fig. B). However, no lesion was found in the other animals, in which the application had been delivered in the fibrous section more cranial in the SCV. Conclusions: Data of this study suggest that circular electroporation ablation, at an energy level that can create deep myocardial lesions, spares the targeted right phrenic nerve, even when applied within a distance of 1 to 2 mm. The absence of any detectable lesion in the fibrous section of the SCV wall, cranial to the myocardial sleeve, suggests that connective tissue is not affected by electroporation ablation. P837 Visualization of electrophysiologically defined junction between the right atrium and the superior vena cava Y. Aizawa Y. Aizawa K. Fukuda K. Fukuda Keio University Hospital, Department of Cardiology , Tokyo , Japan N. Nishiyama N. Nishiyama S. Takatsuki S. Takatsuki K. Nakajima K. Nakajima S. Kashimura S. Kashimura Y. Katsumata Y. Katsumata T. Nishiyama T. Nishiyama T. Kimura T. Kimura K. Fukumoto K. Fukumoto Abstract Purpose: The electrical superior vena cava (SVC) isolation from the right atrium (RA) sometimes can be challenging because of the risks of phrenic nerve injury, SVC stenosis and sinus node dysfunction. To isolate SVC safely and efficiently, identification of the SVC-RA junction (VAJ) is crutial. We aimed to visualize the accurate position of VAJ on the 3D map using decremental conduction property of VAJ in patients with atrial fibrillation AF). Methods: This study consisted of 8 consecutive AF patients (7 males, age 57.6 ± 6.1 years). A 3D mapping catheter was located on the VAJ area during application of single extra-stimulus from the the right atrial appendage (RAA), to discriminate RA potentials and SVC potentials. The electrophysiological VAJ was defined as the most proximal points where the SVC potentials were recorded, which were tagged on the 3D mapping system around the VAJ. Radiofrequency (RF) application for SVC isolation was conducted at the SVC earliest activation site on VAJ. (Figure 1) Results: Around the VAJ, 16.5 ± 3.7 points were tagged on the 3D mapping system. The highest and the lowest VAJ points were located on anterior wall (8/8, 100%) and posterior wall (8/8, 100%), respectively. Difference in level between the highest and the lowest VAJ was 17.1 ± 7.5 mm. The successful SVC isolation was obtained in all patients without any complications. The total number of RF applications was 6.0 ± 3.0 per patient. Conclusions: The plane of electrophysiologically defined VAJ was not perpendicular to the body axis, but slunted. To recognize the precise location of the VAJ might contribute safe and efficacious SVC isolation. Figure 1 P838 Left atrial size is only one predictor for mid-term outcome after ablation of atrial fibrillation using second-generation cryoballoon A. Berkowitsch A. Berkowitsch E. Akkaya E. Akkaya D. Pajitnev D. Pajitnev H. Greiss H. Greiss N. Deubner N. Deubner S. Zaltsberg S. Zaltsberg H. Moellmann H. Moellmann H.F. Pitschner H.F. Pitschner T. Neumann T. Neumann M. Kuniss M. Kuniss Kerckhoff Heart and Thorax Center , Bad Nauheim , Germany Abstract Purpose: Factors predicting outcome after pulmonary vein isolation (PVI) with second-generation cryoballoon (CBA) have not been sufficiently investigated. The aim of this study was to evaluate the impact of several clinical and procedural parameters on outcome after PVI with CBA. Methods: Consecutive patients (pts) ablated in our institution with CBA since May 2012 were enrolled in the study. After a single transseptal access and PV angiography PVI was performed using a 28-mm CBA. Mapping of PV signals before, during, and after each cryo application was performed with a 3F lasso catheter. The procedural endpoint after PVI was defined as complete elimination of all fragmented signals at the PV antrum with verification of entrance and exit block. The primary endpoint of this study was the first documented recurrence of atrial fibrillation (AF), atrial tachycardia, or atrial flutter (>30 sec.). The impact of variables (gender, age, type of AF, history of AF, hypertension, LVEF, CHA2DS2-VASc-Score, common ostium, left atrial size, intra-procedural cardioversion, nadir temperature, number of applications and application time ) was investigated with univariate Cox regression analysis. All pts were followed prospectively with 7-day Holter ECG recordings every three months. Results: The study group consisted of 391 pts with following characteristics: 242 male, paroxysmal AF (PAF) 296(76.2%), median age (IQR)=60(53-66)y, LVEF 62 (59-62)%, history of AF 3.5(1.9-8.2) years, CHA2DS2-VASc-Score 1(1-2), hypertension 262(67.0%) pts, left atrial area (LA area) 19.6 (17.4-22.5) cm2. Common ostium was observed in 41 (10.5%) pts. Nadir temperature was -46 (-49/-43)/pat and number of application was 9 (8-10) /pat with application time 220 (180-240) sec. In 53 (13.6%) pts intra-procedural cardioversion was performed to restore sinus rhythm. After a median follow up of 14 (8/21) months the primary endpoint was reached in 50 of 391 pts (12.8%).There was no significant difference in clinical outcome between patients with PAF (258/296 (87.2%) pts free of recurrence) and persistent AF ((83/95) 87.4%), p=.743. Among all parameters analyzed only LA area was found to be predictive of outcome.The optimal cut-off point for LA area was defined at 23 cm2. Among 310 pts with LA area < 23 cm2 recurrences were noted in 33 (10.6%) vs. 17(21%) in 81 pts with increased LA area ≥23 cm2 (p=0.001), HR=2.27 (95% CI: 1.26-4.07)). Conclusions: PVI with CBA in patients with persistent AF seems to be as effective as in patients with PAF. lA area was revealed to be only one predictor of outcome after PVI with CBA in our cohort. P839 Impact of power on impedance drops with stable and unstable points under the same force-time integral in atrial fibrillation ablation L.B. Shi L.B. Shi W.Y.C. Wang W.Y.C. Wang P.S. Schuster P.S. Schuster B.A. Bortoli B.A. Bortoli S.L.Z. Sun S.L.Z. Sun P.I.H. Per Ivar P.I.H. Per Ivar E.S. Solheim E.S. Solheim O.L.O. Ohm O.L.O. Ohm C.J. Chen C.J. Chen Haukeland University Hospital, Department of Heart Disease , Bergen , Norway Abstract Purpose: Although the important role of force-time integral (FTI) and power for ablation effect of atrial fibrillation has been previously verified, the influence of catheter stability and how to compensate the impact of instability are still unclear. Methods: 418 ablation points were acquired from 22 patients with paroxysmal atrial fibrillation who underwent pulmonary vein isolation for the first time. The points were collected at the beginning of the procedure at separate sites to avoid a mutual effect. Radiofrequency energy was delivered for 60 s at each site. A Thermocool SmartTouch catheter was used for ablation, all data including power, contact force, ablation time and movement range of the catheter tip were recorded on a Carto 3 system. Based on the range of movement during ablation, the ablation points were grouped as stable (<6 mm in diameter, n=345) and unstable (6-12 mm, n=73). Ablation application was interrupted if the movement range was too large (>12mm). The unstable group was sub-classified by power . Impedance drop (ID) was used as a criterion for the measurement of ablation effect. The real-time IDs under various FTI (100-500g·s) were recorded for analysis. Results: IDs were lower in the unstable group compared to the stable group under the same FTI. There was no statistical difference among IDs under different FTI in the unstable group. In sub-groups of unstable points, IDs increased with increase of power but not with increase of FTI (Table). Conclusions: Ablation under an unstable catheter position is less effective than stable position with the same FTI. Increasing power, but not FTI, may compensate the influence of instability. Impacts of power and force-time integral (FTI) on impedance drops (in ohm) under unstable catheter position during atrial fibrillation ablation.  FTI 100 g·s FTI 200 g·s FTI 300 g·s FTI 400 g·s FTI 500 g·s Stable total 9.12±6.45 11.67±7.63 13.36±8.17 14.46±8.92 14.8±9.84 Unstable total 7.24±6.87 9.36±7.23* 10.47±6.00* 10.90±6.99** 11.19±6.93* Unstable 25W 4.45±5.71†† 5.62±6.26†† 7.56±5.47†† 7.20±5.75†† 6.35±5.72†† Unstable 30W 8.96±9.24# 9.97±7.47# 9.51±6.30† 9.36±7.65† 9.96±5.84† Unstable 35W 8.82±5.33 13.00±6.23‡ 13.92±4.61‡‡ 15.60±5.23‡‡ 17.24±3.62‡‡   FTI 100 g·s FTI 200 g·s FTI 300 g·s FTI 400 g·s FTI 500 g·s Stable total 9.12±6.45 11.67±7.63 13.36±8.17 14.46±8.92 14.8±9.84 Unstable total 7.24±6.87 9.36±7.23* 10.47±6.00* 10.90±6.99** 11.19±6.93* Unstable 25W 4.45±5.71†† 5.62±6.26†† 7.56±5.47†† 7.20±5.75†† 6.35±5.72†† Unstable 30W 8.96±9.24# 9.97±7.47# 9.51±6.30† 9.36±7.65† 9.96±5.84† Unstable 35W 8.82±5.33 13.00±6.23‡ 13.92±4.61‡‡ 15.60±5.23‡‡ 17.24±3.62‡‡  * P<0.05, ** P<0.01 compared to stable total. † P<0.05, †† P<0.01 compared to unstable 35W; # P<0.05 compared to unstable 25W. ‡ P<0.05, ‡‡ P<0.01 compared to FTI 100 g·s. &P<0.05 vs FTI100g·s, &&P<0.01 vs FTI100g·s  FTI 100 g·s FTI 200 g·s FTI 300 g·s FTI 400 g·s FTI 500 g·s Stable total 9.12±6.45 11.67±7.63 13.36±8.17 14.46±8.92 14.8±9.84 Unstable total 7.24±6.87 9.36±7.23* 10.47±6.00* 10.90±6.99** 11.19±6.93* Unstable 25W 4.45±5.71†† 5.62±6.26†† 7.56±5.47†† 7.20±5.75†† 6.35±5.72†† Unstable 30W 8.96±9.24# 9.97±7.47# 9.51±6.30† 9.36±7.65† 9.96±5.84† Unstable 35W 8.82±5.33 13.00±6.23‡ 13.92±4.61‡‡ 15.60±5.23‡‡ 17.24±3.62‡‡   FTI 100 g·s FTI 200 g·s FTI 300 g·s FTI 400 g·s FTI 500 g·s Stable total 9.12±6.45 11.67±7.63 13.36±8.17 14.46±8.92 14.8±9.84 Unstable total 7.24±6.87 9.36±7.23* 10.47±6.00* 10.90±6.99** 11.19±6.93* Unstable 25W 4.45±5.71†† 5.62±6.26†† 7.56±5.47†† 7.20±5.75†† 6.35±5.72†† Unstable 30W 8.96±9.24# 9.97±7.47# 9.51±6.30† 9.36±7.65† 9.96±5.84† Unstable 35W 8.82±5.33 13.00±6.23‡ 13.92±4.61‡‡ 15.60±5.23‡‡ 17.24±3.62‡‡  * P<0.05, ** P<0.01 compared to stable total. † P<0.05, †† P<0.01 compared to unstable 35W; # P<0.05 compared to unstable 25W. ‡ P<0.05, ‡‡ P<0.01 compared to FTI 100 g·s. &P<0.05 vs FTI100g·s, &&P<0.01 vs FTI100g·s P840 Head to head comparison between radiofrequency and second generation cryoballon catheter ablation for paroxismal atrial fibrillation. A prospective controlled study S. Ferretto S. Ferretto L. Leoni L. Leoni C. Dalla Valle C. Dalla Valle F. Migliore F. Migliore M. De Lazzari M. De Lazzari M. Siciliano M. Siciliano M. Silvano M. Silvano A. Zorzi A. Zorzi S. Iliceto S. Iliceto E. Bertaglia E. Bertaglia University Hospital of Padova, Cardiac, Vascular and Thoracic Science , Padua , Italy Abstract Background: Catheter ablation based on pulmonary veins (PV) isolation has proven to be a valid technique to treat atrial fibrillation (AF). Aims: To compare radiofrequency ablation (RF-A) and cryoablation (CRYO-A) for the treatment of paroxysmal AF with respect of safety, procedural and fluoroscopy times and mid term efficacy. Methods: 63 consecutive first procedures (33 CRYO-A and 30 RF-A) performed in our laboratory were analyzed. In RF-A a non fluoroscopic navigation system (CARTO™ 3, Biosense Webster Inc.) was used for the reconstruction of the left atrium maps. CRYO-A was performed using the second generation cryoballoon (Arctic Front Advance™, Medtronic Inc., 23 or 28 mm). The primary end-point was detection of any atrial tachyarrhythmias (AT) recurrence off antiarrhythmic therapy during the whole follow up. Results: The two groups resulted similar regarding age, male gender, and presence of structural heart disease. In CRYO-A procedural time resulted shorter (131.0±39.4 min vs 160.5±44.1 min; p=0.007), while fluoroscopy dose area product longer (188563.3±79604.7 mGy*cm2 vs 93895.9±10193.3 mGy*cm2; p<0.001). One groin hematomas for each group was observed. During a mean follow up of 434±236 days, AT relapses were detected in 27.3% CRYO-A patients and in 23.3% RF-A patients (p=0.72). No difference was observed in the event free survival curve (p=0.62). In the first three months after ablation a trend towards a higher recurrence rate in the RF-A was observed (16.7% vs 12.1%, p=0.60), while after this period recurrences were more frequent in the CRYO-A (15.1% vs 6.6%, p=0.28). Conclusion: RF-A and CRYO-A presented similar mid-term efficacy and safety in PV isolation for paroxysmal AF, with a trend towards a lower rate of early recurrences after CRYO-A. P842 Linear ablation of box isolation with biatrial isthmuses ablation as an initial therapy for the persistent and longstanding persistent atrial fibrillation S. Takatsuki S. Takatsuki T. Kimura T. Kimura N. Nishiyama N. Nishiyama K. Nakajima K. Nakajima A. Kunitomi A. Kunitomi S. Kashimura S. Kashimura K. Fukumoto K. Fukumoto Y. Tanimoto Y. Tanimoto Y. Aizawa Y. Aizawa K. Fukuda K. Fukuda Cardiology Department, Keio University Hospital , Tokyo, Japan , Japan Abstract Purpose: Ablation strategy has not been established for the persistent atrial fibrillation (PerAF) necessitating some substrate modification as well as pulmonary vein (PV) isolation. Box isolation created by linear lesions which isolated all 4 PVs and left atrial posterior wall simultaneously with or without biatrial isthmuses ablation were performed and whether it could affect arrhythmogenic substrate of the PerAF were investigated. Methods: Subjects consisted of 53 PerAF and longstanding-perAF patients. Before and after making box isolation, 3-dimensional map of complex fractionated atrial electrograms (CFAE) of the left atrium (LA) were created, then internal DC shock was applied to terminate AF. After cavotricuspid isthmus ablation, atrial burst stimulation with pacing interval from 300ms to 180ms was applied from 3 sites of LA, which was repeated after creation of mitral isthmus ablation. Results: The box isolation eliminated LA surface area of 62.5 ± 14.3 cm2 out of 175.9 ± 25.1cm2 and decreased LA CFAE area from 92.4 ± 31.7 cm2 to 68.3 ± 26.3 cm2, which could not terminate any of AF. AF or atrial tachycardia (AT) was induced in 62.5% of the patients after internal DC shock which was decreased to 32.5% after creation of conduction block on the mitral isthmus. Free of AF/AT recurrence was 37/53 (69.2%) with 6 month follow-up. Conclusions: Box isolation decreased arrhythmogenic substrate and appended mitral isthmus ablation suppressed acute AF/AT induction, resulting sufficient long-term success. Linear ablation approach was feasible and might be a strategy for perAF and longstanding perAF. P843 Less than two minutes, second generation cryoballoon applications achieves acute PVI in 79% without phrenic nerve palsy: preliminary results of the 1-2-3 study J.M. Van Opstal J.M. Van Opstal Medical Spectrum Twente, Cardiology , Enschede , Netherlands M.M.D. Molenaar M.M.D. Molenaar M.F. Scholten M.F. Scholten T. Hesselink T. Hesselink Y.J. Stevenhagen Y.J. Stevenhagen Abstract Purpose: In patients with paroxysmal atrial fibrillation (PAF), the second generation cryoballoon (Arctic Front Advance) significantly improves procedural outcome of pulmonary vein isolation (PVI) compared to the first-generation. However, this goes hand in hand with an increased risk of complications, especially phrenic nerve (PN) palsy (PNP). Considering the increased efficacy and risk of complications, the necessity and safety of the recommended two times 4-minutes cryotherapy per pulmonary vein (PV) might be questioned. The aim of the 1-2-3 study is to assess PVI after different freeze time cycles with the second generation cryoballoon. Methods: This prospective, single blinded study, includes patients with PAF, 4 PVs as assessed by a prior performed CT scan and a left atrial size <40cc/m2. Patients are randomised to two times 1,2 or 3 minutes of cryoballoon applications per vein. Time is started after the balloon temperature reaches the plateau phase of the freezing cycle. PVI is checked by the Achieve mapping catheter directly after each application and at the end of the procedure, also using adenosine. During applications of the right PVs the PN is constantly stimulated and excursion of the diaphragm is monitored manually. If no PVI can be achieved with the assigned cryotherapy duration of 1,2 and 3 minutes, more and/or longer applications are applied until PVI is successful. This is classified as primary unsuccessful PVI. Results: Until now 20 patients (age 55±8.1 years ) have been included. 7/20 patients were randomized to the 1 minute group, 7 and 6 respectively to the 2- and 3-minutes group. In all patients the 28 mm cryoballoon was used. In the 1 minute group 22/28 PVIs were primary successful, in the 2 minutes group 19/28 and in the 3 minutes group 17/24. The total mean application time per cryoapplication, from the start of cryotherapy, was respectively 114±14, 147±42 and 204±50 seconds in the different groups. With additional and/or longer applications, PVI could be achieved in all primary unsuccessful applications. In one patient the right inferior PV could not be isolated due to PNP after isolation of the right superior PV. In 8/26 right sided PVs in the 2- and 3 minutes group, applications had to be terminated prematurely due to loss of PN capture whereas no application had to be terminated untimely in the one minute group. All PNPs were (eventually) transient. Conclusion: Using the second generation cryoballoon two times 114±14 seconds of cryotherapy achieves 79% PVI without PNP. These preliminary results indicate that shorter initial cryoapplications might be considered. P844 Predictive value of atrial remodeling of atrial tachyarrhythmia recurrence after catheter ablation of atrial fibrillation during the long-term follow K. Ejima K. Ejima K. Kato K. Kato K. Arai K. Arai K. Fukushima K. Fukushima R. Henmi R. Henmi D. Yagishita D. Yagishita T. Manaka T. Manaka K. Ashihara K. Ashihara M. Shoda M. Shoda N. Hagiwara N. Hagiwara Tokyo Women's Medical University, Department of Cardiology , Tokyo , Japan Abstract Purpose: Both the left atrial volume index (LAVI) and estimated total atrial conduction time measured using tissue Doppler imaging of the atria (PA-TDI duration) are echocardiographic parameters reflecting atrial remodeling. The aim of this study was investigate their prognostic value for atrial tachyarrhythmia (ATA) recurrence after radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF). Methods and Results: We analyzed the data from 129 consecutive patients who underwent preprocedural transthoracic echocardiography in sinus rhythm and RFCA for AF. At a mean of 29±10 months after single sessions, 52 (40%) patients had ATA recurrences. The patients with ATA recurrences had a larger LAVI (p=0.014) and longer PA-TDI (p=0.007) than those without recurrences. Although the predictive accuracy of the LAVI cut-off value (>35.1ml/m2) and PA-TDI (>145.2ms) predicting a recurrence after RFCA estimated by an ROC curve were relatively low (AUC 0.63 and 0.64, respectively), the combined index (LAVI >35.1ml/m2 and PA-TDI >145.2ms) was the only independent predictor of recurrence after a single RFCA (HR 2.9, 95%CI 1.55-5.33, p=0.0011) in the multivariate Cox regression analysis. Although 29 patients (30%) required repeat procedures, 95 (97%) of 98 patients not falling into a combined index were free from any ATAs without antiarrhythmic drugs at a mean of 26±11 months. Conclusion: Atrial remodeling was a useful predictor of recurrence following ablation procedure in patients with AF. P846 AF ablation with the new circular, irrigated multipolar ablation catheter nMARQTM catheter: a single center experience M. Gwechenberger M. Gwechenberger B. Richter B. Richter M. Marx M. Marx C. Gangl C. Gangl H. Goessinger H. Goessinger Medical University of Vienna , Vienna , Austria Abstract Background: Pulmonary vein isolation (PVI) is the cornerstone in the treatment of atrial fibrillation (AF.) Novel catheters emerge in order to improve outcomes. We report the first 104 cases with the new circular, irrigated multipolar ablation catheter nMARQTM (Biosense Webster, CA, USA). Methods and Results: This study reports a single center, non-randomized study, which included 104 patients (64 male, mean age 66.3+10.3 years, paroxysmal AF 62.4%) treated with nMARQTM catheter for PVI. Fourty percent of the patients had a history of previous interventional PVI and 1.8 % underwent prior surgcial PVI. After transseptal puncture the nMARQTM catheter was used for ablation. Vein isolation was confirmed using the LASSO catheter. Atrial debulkment by the use of the nMARQTM catheter was added in persistent AF. The mean follow up was 6.9 +4.1 months. Freedom from atrial fibrillation after one single procedure was 67.6% in patients with paroxysmal AF and 41,5% in patients with persistent AF. The mean number of energy applications per patient was 14.9±5.3 and the mean duration was 9 min 41 sec± 4 min 12sec. Complications occurred in 3,7% including air embolism, groin hematoma requiring surgical intervention, AV fistula and esophageal ulcer in one patient each. Conclusions: In this single center study the use of the nMARQTM catheter led to satifactory short term success rates for both paroxysmal and persistent AF. The nMARQTM catheter can be used safely. P847 Successful endoscopic surgical ablation in patients with persistent atrial fibrillation is associated with recovery of atrial transport function C. Muneretto C. Muneretto 1 University of Brescia, Department of Cardiac Surgery , Brescia , Italy G. Bisleri G. Bisleri 1 University of Brescia, Department of Cardiac Surgery , Brescia , Italy F. Rosati F. Rosati 1 University of Brescia, Department of Cardiac Surgery , Brescia , Italy E. Gorga E. Gorga 2 University of Brescia, Department of Cardiology , Brescia , Italy A. Curnis A. Curnis 2 University of Brescia, Department of Cardiology , Brescia , Italy E. Chiari E. Chiari 2 University of Brescia, Department of Cardiology , Brescia , Italy Abstract Purpose: Minimally invasive surgical treatment of stand-alone atrial fibrillation has gained popularity over the past decade especially in presence of persistent atrial fibrillation. Nevertheless, there is paucity of data about the atrial transport function following successful restoration of sinus rhythm (SR) by means of a totally endoscopic, epicardial box lesion set. Methods: Among 53 patients with persistent AF and scheduled to undergo closed-chest, epicardial beating heart surgical ablation (box lesion set) with a radiofrequency device, a comprehensive echocardiographic assessment of the left atrial(LA) function was performed either pre-operatively (T0) and postoperatively at 6 months (T1) and 12 months (T2); the following parameters were evaluated: LVEF, LA diameter-area-volume, LA total - passive and active emptying fraction, A' wave, deceleration time. Only patients with stable sinus rhythm during the follow-up (n°=45) were included in the analysis in order to evaluate the impact of the box lesion set following SR restoration. Results: There was no considerable difference in the LVEF over the follow-up period (T0=60.9±4.6% vs T1=61.9±4.3% vs T2=62.3±6.2%; p=0.392); however, there was a significant reduction either in terms of LA diameter(T0=48.8±3.5% vs T1=44.2±3.6 mm vs T2=43±6.6 mm;p<0.001), LA area(T0=28.2±3.6 cm2 vs T1=24±3.9cm2 vs T2=23.6±3.2 cm2 ;p<0.001), LA maximal volume (T0=99.8±16.1 mL vs T1=84.2±18.6 mL vs vs T2=74.2±18.1 mL; p<0.001), LA minimum volume (T0=73±13 mL vs T1=52.3±14 mL vs T2=43.4±13.8 mL; p<0.001) with a considerable improvement also in deceleration time (T0=165.2.7±31.3 ms vs T1=190.8±41.2 ms vs T2=202.8±78.4 ms; p=0.004). Moreover, there was a recovery of atrial booster function as demonstrated by an active LA emptying fraction of (T0=0% vs T1=21.1±9.2% vs T2=23.9±10%; p<0.001 T1/T2 vs T0), a normalisation of A' value (T0=0 vs T1=6.7±2.6 vs T2=6.6±1.8; p<0.001 T1/T2 vs T0 ). Conclusions: Following successful surgical ablation with a box lesion set and stable restoration of sinus rhythm, a significant recovery of an effective atrial transport function was already detected at 6 months and maintained over the postoperative follow-up period up to 12 months. P848 Initial experience with a new image integration module designed for reducing radiation exposure during electrophysiological ablation procedures O. Cano Perez O. Cano Perez 1 Hospital Universitari i Politecnic La Fe, Instituto Investigacion Sanitaria La Fe , Valencia , Spain P. Alonso P. Alonso 1 Hospital Universitari i Politecnic La Fe, Instituto Investigacion Sanitaria La Fe , Valencia , Spain J. Osca J. Osca 2 Hospital Universitari i Politecnic La Fe , Valencia , Spain A. Andres A. Andres 1 Hospital Universitari i Politecnic La Fe, Instituto Investigacion Sanitaria La Fe , Valencia , Spain M.J. Sancho-Tello M.J. Sancho-Tello 2 Hospital Universitari i Politecnic La Fe , Valencia , Spain J. Olague J. Olague 2 Hospital Universitari i Politecnic La Fe , Valencia , Spain A. Salvador A. Salvador 2 Hospital Universitari i Politecnic La Fe , Valencia , Spain L. Martinez-Dolz L. Martinez-Dolz 2 Hospital Universitari i Politecnic La Fe , Valencia , Spain Abstract Purpose: Reduction of radiation exposure during cardiac arrhythmia ablation procedures is desirable. We sought to evaluate the utility of a new image integration module (CARTOUNIVU) in reducing fluoroscopy times and dosages during left atrial arrhythmia (LAA) and ventricular tachycardia (VT) ablation procedures. Methods: Consecutive patients undergoing LAA (n=28)/VT(n=13) ablation using the CARTOUNIVU module were included. Total fluoroscopy time, radiation dose (total dose area product [tDAP], effective dose [ED]) and procedure duration were evaluated. A retrospective cohort of patients who underwent LAA(n=16)/VT(n=8) ablation without the new image integration module served as control group. Results: The use of the new image integration module significantly reduced mean fluoroscopy time (5.2 min. [IQR 1.9;6.8] in LAA ablation UNIVU group vs. 28.2 min. [IQR 15.3;37.8] in the control group, P<0.001; 9.8 min. [IQR 4.5;13.1] vs. 25.5 min. [IQR 14.1;30.9] for VT ablation, P=0.013), tDAP (2088 cGy/cm2 [IQR 664;2911] vs. 5893 cGy/cm2 [IQR 3088;8483], P<0.001 for LAA ablation; 3917 cGy/cm2 [IQR 948;4217] vs. 12377 cGy/cm2 (IQR 3385;23157) for VT ablation patients, P=0.025) and ED (4.1 mSv [IQR 1;5.8] vs. 11.8 mSv [IQR 6.2;16.9] for LAA ablation patients, P<0.001; 7.8 mSv [IQR 1.9;8.4] vs. 24.7 mSv [IQR 6.8;46.3] for VT ablation patients, P=0.025). Procedure duration did not significantly changed (174±45 min vs. 197±36 min for LAA ablation, P=0.083; 201±51 min. vs. 201±63 min. for VT ablation, P=0.860). No serious adverse events related to the use of the CARTOUNIVU module occurred. Conclusions: The new image integration module significantly reduced total fluoroscopy time and mean radiation dose without influence in procedure duration during ablation of complex atrial and ventricular arrhythmias. Figure 1 P849 A novel tool for mapping multiple rhythms from a single mapping procedure L. Ptaszek L. Ptaszek 1 Massachusetts General Hospital, Cardiac Arrhythmia Service , Boston , United States of America B. Moon B. Moon 2 St. Jude Medical , Minneapolis , United States of America F. Sacher F. Sacher 3 Hospital Haut Leveque , Bordeaux-Pessac , France P. Jais P. Jais 3 Hospital Haut Leveque , Bordeaux-Pessac , France S. Mahapatra S. Mahapatra 2 St. Jude Medical , Minneapolis , United States of America M. Mansour M. Mansour 1 Massachusetts General Hospital, Cardiac Arrhythmia Service , Boston , United States of America Abstract Purpose: Mapping multiple rhythms typically requires iterative mapping, which can be time-consuming. The ability to quickly map secondary rhythms of interest from the primary map recording has the potential to decrease mapping and total procedure times, which could benefit individual patients and health economics. Methods: Manual and automated electroanatomical mapping was performed in the RV and LV of 5 swine using a 4-pole ablation catheter and new mapping software during sinus rhythm (40 maps). After each map was completed, 12-lead ECG morphology templates of ectopic PVCs were selected from recorded datasets. Automated construction of PVC conduction maps was then performed retrospectively (20 maps). Results: Combined RV and LV mean mapping times (±StDev) were 643 (±249), 408 (±118) and 36 seconds (±9) for Live-Manual (LMan), Live-Automated (LAuto) and Recorded-Automated (RAuto) mapping, respectively. Statistically significant reductions in mapping time were observed in the LMan to LAuto (P-value = 0.001) and LAuto to RAuto (P-value < 0.001) comparisons. Rapid automated "re-mapping" from the original mapping segment produced additional PVC maps in a mean of 6% (StDev 1.9) and 9% (StDev 0.01) of manual and automated mapping times, respectively (Figure). Conclusion: The ability to automatically create maps of additional rhythms in less than 10% of the time of creating a new map has the potential to shorten certain EP procedures. The data presented relate to ventricular mapping, but the same method could apply to atrial mapping, thus allowing for mapping secondary and spontaneous atrial arrhythmias in a fraction of the time possible with compared with methods used in practice today. Reduced mapping and procedure time may produce significant health economic gains. Figure P850 Catheter ablation of ventricular tachycardia in the presence of an old endocavitary thrombus: the role of intracardiac echocardigraphy P. Peichl P. Peichl D. Wichterle D. Wichterle R. Cihak R. Cihak B. Aldhoon B. Aldhoon J. Kautzner J. Kautzner IKEM , Prague , Czech Republic Abstract Introduction: Catheter ablation of ventricular tachycardia (VT) in patients (pts) with structural heart disease (SHD) is an effective treatment for prevention of arrhythmia recurrences. However, endocardial ablation may be challenging in the presence of the organized LV endocavitary thrombus. We aimed to analyze the results of VT ablation in the presence of old LV thrombus. Methods: Out of a total 235 consecutive pts undergoing VT ablation for SHD guided by intracardiac echocardiography (ICE, Accuson, Siemens), 8pts with detectable thrombus within the LV cavity were identified (3.4% of total population, mean age 68±8years). All pts underwent preprocedural transthoracic echocardiography to rule out the LV thrombus, however, in 6/8pts (75%) the thrombus was undetected and was revealed only by ICE. Results: All pts with old LV thrombus had postinfarction aneurysm. In all cases the thrombus was organized and oval in shape. The mean interval between the index myocardial infarction and ablation was 23±8years. The mean clinical VT cycle length was 370±182ms. The thrombus prevented assessment of endocardial electrograms within its area, however, catheter ablation was successfully performed in the vicinity of the thrombus. No procedure related complications were observed. All inducible VTs could be abolished in 75% of pts. During the follow up of 13±15months, only one patient had VT recurrence. Conclusions: ICE is superior to transthoracic echocardiography for detection of old endocavitary thrombi. These are typically present in pts with very long history of post-infarction LV aneurysm. In such cases, catheter ablation can be performed safely with a high success rate P852 Distinct and wide variations exist in the morphology of the cavo-tricuspid isthmus:utility of real-time intracardiac echocardiography M. Yokokawa M. Yokokawa T. Morishita T. Morishita K. Ishida K. Ishida K. Arakawa K. Arakawa H. Uzui H. Uzui K. Hisazaki K. Hisazaki K. Kaseno K. Kaseno N. Amaya N. Amaya D. Aoyama D. Aoyama H. Tada H. Tada University of Fukui , Fukui , Japan Abstract Background: Right atrial angiography (RAG) is useful for assessing the morphology of the cavo-tricuspid isthmus (CTI). However, it may overlook complicated CTI morphologies. A few studies have reported CTI ablation with intracardiac echocardiography (ICE). Methods: This study included 90 consecutive patients with atrial flutter. Before the ablation, the CTI morphology was assessed by both ICE (CartoSound®) and bidirectional RAG. The CTI morphology was categorized into 3 groups: flat (depth <2 mm), concave (depth >2 mm), and pouch (a flat part and pouchlike recess) morphologies. The relation between the CTI morphology and radiofrequency (RF) catheter ablation parameters was also examined. Results: In the ICE imaging, the CTI morphology could be clearly assessed. The CTI was flat in 23 (25%) patients, but apparently concave in another 38 (42%; Figure A). The remaining 29 (33%) had a distinct pouch (Figure B). The majority of the pouches were located from the middle to the IVC side of the CTI. The Eustachian ridge/valve (ER) was also apparent in 51 (57%) patients. In the bidirectional RAG, a pouch was detected in 21 (23%) patients and ER in 15 (17%), and was less than that of the CTI. A complete block line of the CTI was achieved in all patients without any complications. In patients with a pouch and/or ER, a complete CTI block line could be created by careful manipulation of the catheter at those portions. The morphological differences in the CTI did not statistically affect the procedure time, or total amount or duration of RF energy delivered. Conclusions: A considerable number of patients had a complicated CTI morphology with a pouch or ER. Real-time ICE was crucial for clarifying the morphological CTI variations and completing the CTI ablation effectively and safely. Figure P853 Waiting time after cavo-tricuspid isthmus ablation for typical atrial flutter and long term procedural success S. Marchandise S. Marchandise C. Scavee C. Scavee C. Barbraud C. Barbraud C. De Meester C. De Meester M.C. Gonzalez M.C. Gonzalez C. Goesaert C. Goesaert Y. Reis-Pinheiro Y. Reis-Pinheiro J.B. Le Polain De Waroux J.B. Le Polain De Waroux Cliniques Saint-Luc UCL, Cardiology , Brussels , Belgium Abstract Introduction: The aim of this study was to determine the rate of recurrent Atrial Flutter (AFl) and Atrial Fibrillation (AF) after isolated cavotricuspid isthmus (CTI) ablation and to evaluate the impact of a waiting period to search for early resumption of the CTI block on the long-term outcome. Method: Between January 2010 and December 2013, 319 consecutive patients (age: 67 ± 12 years; male: 78%) were referred to our center for typical AFl ablation. 155 patients underwent a conventional CTI ablation procedure with continuous re-evaluation of the CTI block during 25 minutes (WT+) while 164 were treated with no waiting period (WT-). All patients were regularly followed-up at 1, 3 and then every 6 months with a medical questionnaire and 24 hours Holter-ECG. Result: At baseline, demographic and electrophysiological parameters were similar in both groups. In all patients, a bidirectional block of conduction in the CTI was achieved. In the WT+ group, 10 patients (7%) presented a recovery across the CTI (time to recovery: 17 ± 7′) and were re-ablated at the end of the waiting period. After a median follow-up of 21 months (range: 1 to 51), the rate of recurrent AFl was significantly higher in the WT- group as compared to the WT+ group (11.6% (19/164) vs. 2.5% (4/155) respectively; p=0.007, figure 1). However, there are no significant difference in AF recurrence between the WT- and the WT+ groups (30% (45/155) vs. 32% (53/164), p=0.66). Among these patients with AFl. clinical recurrence, 4 were treated medically and 19 underwent a second ablation procedure. During Follow-up, ablation procedure occurred in 28 patients in the WT- group (16 AFl redo and 12 AF ablation) and in 10 patients form the WT+ group (3 AFl redo and 7 AF ablation). Conclusion: Waiting 25 minutes after CTI ablation to check for early resumption allows for decreasing significantly the rate of recurrent atrial flutter but have not influence on the risk of further episode of AF. P854 Success and limitation of epicardial VT ablation procedures in a large single centre cohort G.A. Szoelloesi G.A. Szoelloesi T. Deneke T. Deneke Heart Center Bad Neustadt, Electrphysiology , Bad Neustadt a.d. Saale , Germany M. Roos M. Roos A. Schade A. Schade K. Nentwich K. Nentwich J. Krug J. Krug P. Halbfass P. Halbfass P. Mueller P. Mueller Abstract Purpose: Epicardial ablation (EA) is one option to treat VT. Little is known about acute success rate and limitations of this procedure. Methods: From 01/2012 to 10/2014 patients (pts) undergoing EA were included. Epicardial access was gained with a subxyphoidal puncture in an anterior or posterior approach. Coronary vessels where visualized by angiography and, from October 2013 on, were integrated as fluoro images in the 3-D mapping system (CARTO Univu). Acute success rate, complications and limitations of the EA procedure were analysed. Results: A total of 50 EA out of 420 VT procedures were performed: 42/8 m/f (67+/-11y) for DCM (n=30), CAD (n=12) and other CM (n=8, 3/8 with previous non-coronary cardiac surgery). In 6% (n=3) after previous cardiac surgery an epicardial approach was not possible due to extensive adhesions. On the other hand, in 8% (n=4) the epicardial access was the only feasible access to the left ventricle due to double mechanical valve replacement (n=1), failed endovascular access to the left ventricle (n=1), thrombus in the left cardiac cavities (n=2). One procedure (2%) was stopped due to a relevant pericardial effusion after gaining epicardial access. Fifteen pts (28%) had an epicardial approach after failed previous endocardial ablation procedures (10 DCM, 2 ARVC, 1 CAD). The remaining 32 pts (70%) had a combined epicardial-/endocardial approach. Fluoroscopy and procedure time with and without Univu was 28+10.6 / 31+17.2min p=0.46 and 208+60.6 / 231+91.4min, p=0.32. In 30 pts (60%) VT was inducible prior to ablation. Non inducibility of any VT was achieved in 8 pts (16%) due to endocardial ablation, in 17 cases (34%) due to EA, and in 5 pts (10%) due to a combination of both ablation strategies. Three pts remained inducible for the clinical tachycardia. In the remaining 17 pts (34%) a substrate modification including abatement of all late potentials in low-voltage areas was pursued. Reason for failed complete epicardial abolishment of all late potential were the proximity of ablation to a coronary vessel in 4 (8%), phrenic nerve capture in 2 (4%) or an overlaying fat pat in the region of ablation in 2 (4%) pts. Conclusion: EA can safely be done with a low complication rate including pts after previous non-coronary cardiac surgery. Carto Univu had no impact on fluoroscopy or procedure time. The limitation for an epicardial access is given by anatomical circumstances and pericardial adhesions. Mainly for DCM a combined endo-/epicardial approach may be beneficial. In our collective the target for successful ablation was on the endocardium despite an EA approach in 16%. P855 Ablation of frequent pvc in primary prevention patients meeting criteria for icd implant. safety and appropriateness of withholding the implant D. Penela D. Penela 1 Arrhythmia section, Cardiology Dep. Thorax Institute. Hospital Clinic, Universitat de Barcelona , Barcelona , Spain J. Acosta J. Acosta 1 Arrhythmia section, Cardiology Dep. Thorax Institute. Hospital Clinic, Universitat de Barcelona , Barcelona , Spain L. Aguinaga L. Aguinaga 2 Sociedad Latinoamericana de Estimulación Cardíaca y Electrofisiología. , Argentina , Argentina L. Tercedor L. Tercedor 3 Hospital Universitario Virgen de las Nieves, Unidad de Arritmias, , Granada , Spain J. Fernandez-Armenta J. Fernandez-Armenta 1 Arrhythmia section, Cardiology Dep. Thorax Institute. Hospital Clinic, Universitat de Barcelona , Barcelona , Spain L. Mont L. Mont 1 Arrhythmia section, Cardiology Dep. Thorax Institute. Hospital Clinic, Universitat de Barcelona , Barcelona , Spain A. Berruezo A. Berruezo 1 Arrhythmia section, Cardiology Dep. Thorax Institute. Hospital Clinic, Universitat de Barcelona , Barcelona , Spain D. Andreu D. Andreu 1 Arrhythmia section, Cardiology Dep. Thorax Institute. Hospital Clinic, Universitat de Barcelona , Barcelona , Spain P. Sanchez P. Sanchez 1 Arrhythmia section, Cardiology Dep. Thorax Institute. Hospital Clinic, Universitat de Barcelona , Barcelona , Spain J. Brugada J. Brugada 1 Arrhythmia section, Cardiology Dep. Thorax Institute. Hospital Clinic, Universitat de Barcelona , Barcelona , Spain Abstract Introduction: Ablation of frequent premature ventricular complex (PVC) has shown to improve left ventricular ejection fraction (LVEF) in patients with LV dysfunction. The objective of this study is to evaluate if patients candidate for primary prevention (PP) implantable cardioverter-defibrilator (ICD) implant could remove this indication after PVC abolition. Methods: Sixty-two [29 (47%) men, 53±13 years old, 10 ischemic heart disease] consecutive patients with PP indication for ICD implant and frequent PVC underwent PVC ablation. ICD implant was withheld and indication was re-evaluated at 6 and 12 months after ablation. Results: LVEF progressively improved from 28±4% baseline to 41±11% and 42±12 % at 6 and 12 months respectively, (p<0.001). NYHA class improved during the follow-up from 2.3±0.5 baseline to 1.4±0.5 and 1.5±0.5 at 6 and 12 months respectively, (p<0.001). Thirty-nine (63%) patients removed the indication for PP-ICD implantation during the follow-up, 36 (92%) of them within the first 6 months. Baseline PVC burden and a sustained successful ablation were independent predictors for removing the indication of ICD implantation. A cut-off value of 17% PVC burden had a sensitivity of 95% and a specificity of 91% for removing ICD indication after ablation. No sudden cardiac deaths or malignant ventricular arrhythmias were observed. Conclusion: In patients with frequent PVC, ablation improves LVEF and allows removing the PP-ICD implant indication in the majority of them. To withhold the ICD implant and a 6 months revaluation for ICD indication after ablation seems to be a safe and appropriated strategy. P856 Contact force-guided versus contact force-blinded catheter ablation of typical atrial flutter: a prospective study S. Venier S. Venier J.G. Andrade J.G. Andrade M. Dubuc M. Dubuc K. Dyrda K. Dyrda P. Guerra P. Guerra P. Khairy P. Khairy B. Mondesert B. Mondesert L. Rivard L. Rivard B. Thibault B. Thibault L. Macle L. Macle Montreal Heart Institute, Electrophysiology , Montreal , Canada Abstract Purpose: Whether contact force (CF) sensing ablation technology is useful for CavoTricuspid Isthmus (CTI) ablation is unknown. We prospectively evaluated procedural parameters and outcomes of CF-Guided versus CF-Blinded CTI ablation for atrial flutter in our academic institution. Methods: Sixty-six consecutive patients (mean age 62±12 yrs) undergoing CTI ablation for atrial flutter were prospectively enrolled to CF-Blinded (n=30) or CF-Guided (n=36) groups. A ThermoCool SmartTouch catheter (power 25-35 W) was used in all. The procedural endpoint was bidirectional isthmus block following a 20-min waiting period. In the CF-Guided group, CF target range was 10-25g whereas in the CF-Blinded group, the operator was blinded to CF data. Post-hoc analyses of CF parameters were performed to evaluate the optimal CF. Results: The procedural endpoint was achieved in all patients. No major complications were seen. Total radiofrequency (RF) energy delivery required to achieve bidirectional block was significantly lower in the CF-Guided group compared to the CF-Blinded group (15.0±8.7 min vs 19.2±12.4 min, p=0.01). Fluoroscopy duration was 8.6±6.2 min in the CF-Guided group vs 15.5±7.4 min in the CF-Blinded group (p=0.02). Procedure duration was 83±42 min in the CF-Guided group vs to 94±37 min in the CF-Blinded group (p=0.60). Post-hoc analysis of all ablation procedures showed a significant correlation between CF and total RF delivery time (r2=0.17; p=0.01). Conclusions: CTI ablation for atrial flutter using CF-Guided is associated with a significant reduction in RF delivery and fluoroscopy times. A significant correlation between CF and total RF delivery time was observed. Correlation between CF and RF duration P857 Outcomes after multiple catheter ablations of ventricular tachycardia in patients with structural heart disease B. Dinov B. Dinov C. Stevanello C. Stevanello A. Bollmann A. Bollmann S. Rolf S. Rolf P. Sommer P. Sommer G. Hindricks G. Hindricks A. Arya A. Arya University of Leipzig, Heart Center, Department of Electrophysiology , Leipzig , Germany Abstract Purpose: Catheter ablation (CA) of ventricular tachycardia (VT) is increasingly being adopted as a treatment in patients with recurrent VT and structural heart disease (SHD). However, VT recurrences after CA are common and repeated CA may be necessary. The purpose of this study was to evaluate the efficacy and safety of repeated VT ablation procedures in patients with SHD. Methods: Out of 300 patients (87.3% male, mean age 65 ±12 years, mean ejection fraction 33% ± 11, ICM in 205 pts) ablated for sustained VT, 193 (64.3%) patients with VT recurrence were identified. Of them, 91 patients (30.3%) underwent ≥ 2 VT ablations, 29 (9.6%) ≥ 3 and 8 (2.7%) ≥ 4 procedures over a median follow-up of 21 months; IQR 11 -24. Results: Acute success was achieved in 77.3% of the patients ablated once, in 71.3% after the second CA, in 66.7% after the third CA, and in 88.9% after the fourth CA. Periprocedural complications occurred in 9 patients (9%) during the first CA, 4 patients (4.4%) during the second CA, 1 patients (3.4%) during the third CA, and in none during the fourth CA; p=NS. VT recurrence rates after each subsequent ablation was 64.3%, 61.7%, 62.5%, and 55.6%. No significant progression in ventricular impairment and coronary artery disease were observed at every new CA. The number of repeated CA was an independent predictor for cumulative VT recurrence with a HR=1.53; 95% CI 1.26-1.86; P<0.0001 for each new CA. Conclusion: Repeated VT ablations in patients with SHD had similar acute success and safety. However, the number of previous CA was associated with increased probability for cumulative VT recurrence. Alternative therapeutic strategies should be attempted in patients after multiple failed CA. P858 Ablation of tachyarrhythmias in early childehood L. Svintsova L. Svintsova 1 Federal State Budgetary Scientific Institution Research Institute for cardiology , Tomsk , Russian Federation I. Kovalev I. Kovalev 2 Research and Clinical Institute for Pediatrics at the Pirogov Russian National Research Medical Univ , Moscow , Russian Federation S. Krivolapov S. Krivolapov 1 Federal State Budgetary Scientific Institution Research Institute for cardiology , Tomsk , Russian Federation R. Batalov R. Batalov 1 Federal State Budgetary Scientific Institution Research Institute for cardiology , Tomsk , Russian Federation S. Popov S. Popov 1 Federal State Budgetary Scientific Institution Research Institute for cardiology , Tomsk , Russian Federation Abstract According to last consensus of experts, there is an age borderline of 5 years, after which radiofrequency ablation (RFA) becoming first line therapy in most tachyarrhythmias. We study safety and efficacy of RFA in children under 5 years old. Methods: From 2002 88 patients underwent RFA in age of five and under. There were 46 patients with WPW, 29 with atrial tachy, 8 with ventricular arrhythmias and 5 with AVNRT. Majority of patients were at age of 4-5 years and under 1 year old, 35 and 22 correspondingly. Ablation was performed after failure of medication. Signs of arrhythmogenic cardiomyopathy had 68% of patients. For EP-study and RFA were used one 5 Fr or 7Fr ablation catheter and one diagnostic catheter. Usually bifemoral access was used, but in some cases we also used transesophageal reference catheter. In 20 patients with atrial ectopy we used non-fluoroscopic navigation system that allows to minimize radiation exposure. Access to the left side of the heart was performed through PFO, otherwise in 8 patients it was femoral artery puncture and in 3 patients it was atrial septal puncture. RFA was performed with 55C with starting power 20W, in case of conduction system damage risk a starting power was 5-10 W. Results: First RFA procedure was effective in 78 patients (88,5%) but in 18 cases (23%) there was recurrence that was treated with 2nd procedure in all cases. There were still 3 cases of second recurrence in this group and third effective procedure was performed with good long term follow up. In 10 patients that was ineffective with first procedure in 6 cases there was a second procedure with good long term efficacy. That means that in general RFA was effective in 84 patients out of 88 - 95%. Intraprocedural complications were transient AV-conduction disturbances in 4 patients, transient right and left bundle branch block in 3 patients due to bumping. In one case with septal puncture there was asymptomatic hemopericardium. Reverse remodeling of arrhythmogenic cardiomyopathy in all patients. Conclusions: RFA is safe and effective approach for difficult heart rhythm disorders management when medication fails. There is higher recurrence rate possibly due to minimally effective power applied. It is important to have echo and cardiac surgery back up for management of possible complications. P859 Effect of Non-sustained ventricular tachycardias burden on electrical therapies among ICD patients with left ventricular dysfunction J. Jimenez-Candil J. Jimenez-Candil P. Perdiguero P. Perdiguero E. Garcia-Piney E. Garcia-Piney J. Morinigo J. Morinigo J. Hernandez Hernandez J. Hernandez Hernandez A. Martin A. Martin P.L. Sanchez P.L. Sanchez University Hospital of Salamanca , Salamanca , Spain Abstract Non-sustained ventricular tachycardias (NSVT) are frequently observed among ICD patients with left ventricular dysfunction (LVD). Whether NSVT are related to the type and response to ICD therapies is unknown. Objective: To evaluate prospectively the relationship between NSVT burden and electrical therapies due to monomorphic VT (MVT). Methods: 416 patients with LVD (LVEF < 50%) and standard indications for ICD without Cardiac Resynchronization Therapy were followed for 41±27 months after implant. ICD programming (detection and therapies) was standardized, including antitachycardia pacing (ATP) as first therapy for slow (CL <390 ms) and fast VT (CL: 250-320 ms). NSVT was defined as any VT of ≥5 beats which did not met the detection criteria occurring within the first 6 months after ICD implant. Results: A total of 250 patients (60%) presented at least one NSVT (median=2; interquartile range=0-7). We classified the patients into three groups according to the number of NSVT: no NSVT (n=166, group 1); 1-5 NSVT (n=130, group 2) and >5 NSVT (n=120; group 3). The cumulative incidence of appropriate therapy due to monomorphic VT (MVT) was: 28%, 44% and 66% in groups 1, 2 and 3, respectively (p<0.001; log-rank test). During the follow-up, 1441 MVTs were recorded in 183 patients (primary prevention: 55%; LVEF: 31±8; ischemic etiology: 65%). ATP was effective in 1063 (74%), 16 were slowed but not terminated by ATP and 362 (25%) MVTs required at least one shock (SH) to be terminated. The adjusted mean ATP effectiveness per patient was 74% (95% CI: 69-79), Generalized Equation Estimating Method (GEEM). ATP was more effective in patients with >5 NSVT: 70% (59-82, group 1), vs. 66% (54-77, group 2) vs. 82% (76-89, group 3); p=0.02 (groups 1-2 vs. 3), GEEM. As a consequence, the proportion of MVT terminated with SH was significantly lower in patients with >5 NSVT: 30% (18-40) vs. 33% (22-42) vs. 16% (10-22); p=0.01 (GEEM). Although the mean of MVTs per patient increased with the number of NSVT (5 vs. 7 vs. 10; p=0.06 for trend) the mean of SH did not (1.1 vs. 1.4 vs. 1.5; p=0.6 for trend). Conclusions: 1-Among ICD patients with LVD, the burden of NSVT within the six months after implant is associated with an increase in the incidence of appropriate therapies due to MVT. 2- However, since the ATP effectiveness is higher in patients having more NSVT, these individuals have a lower proportion of MVT terminated with SH and a similar promethium of SH per patient. 3- Among patients with >5 NSVT, a significant proportion of MVT could be self-terminating. P860 Primary prevention in ischemic cardiomyopathy in Brazil: should we really do this? G. Peixoto G. Peixoto M.S. Rocha M.S. Rocha S.F. Siqueira S.F. Siqueira M.M. Lensi M.M. Lensi S.A.D. Nishioka S.A.D. Nishioka R.A. Teixeira R.A. Teixeira W.A. Hueb W.A. Hueb L.A. Machado Cesar L.A. Machado Cesar R. Costa R. Costa M. Martinelli M. Martinelli Heart Institute (InCor) - University of Sao Paulo Faculty of Medicine (FMUSP) , Sao Paulo , Brazil Abstract Purpose: Patients with ischemic cardiomyopathy and low left ventricular ejection fraction (LVEF) are at risk of arrhythmia related to sudden cardiac death (SCD). Implantable cardioverter defibrillator (ICD) is beneficial in reducing mortality; however, the public health system in Brazil does not support primary prevention. The aim of this study was to determine the incidence of SCD in patients with ischemic cardiomyopathy from a tertiary hospital in Brazil to speculate the number needed to treat (NNT) if they had been treated with an ICD. Methods: This is an analysis of the Revision (Registry of Ischemic Ventricular Dysfunction) study, which is a prospective observational study, including patients with chronic coronary artery disease (CAD) and LVEF ≤35%, followed in a tertiary hospital. Results: Between August 2010 to January 2014 we included 508 patients. Mean age was 65.7±11.0 years, 75.9% were men, atrial fibrillation was present in 9.9% of patients, left bundle branch block in 14.8% and the mean LVEF was 0.29±0.05. Hypertension, diabetes and renal disease were present in 86.8%, 53.2%, and 51.7%, respectively. During a mean follow-up of 19.0±9.7 months, there were 80 deaths, five due to SCD. Four patients underwent an ICD implantation for secondary prevention. If these four patients had not been resuscitated, it would be nine SCD (1.8% of the total population) and the total mortality would be 16.5% (84/508). Therefore, an ICD for primary prevention would save nine lives and the total mortality would reduce to 14.7% (75/508). This represents an absolute risk reduction of 1.8%, yielding a NNT of 55 in 19 months of follow-up. Conclusions: Compared to the previous studies of primary prevention (MADIT II and SCD-Heft), the cohort of ischemic cardiomyopathy with low LFEV from a tertiary hospital in Brazil presents a higher NNT. P861 Newly detected atrial arrhythmic episodes in single lead ICD with atrial sensor and early clinical interventions triggered by remote monitoring V. Calzolari V. Calzolari 1 Hospital Santa Maria di Ca Foncello, Division of Cardiology , Treviso , Italy M. Crosato M. Crosato 1 Hospital Santa Maria di Ca Foncello, Division of Cardiology , Treviso , Italy L. De Mattia L. De Mattia 1 Hospital Santa Maria di Ca Foncello, Division of Cardiology , Treviso , Italy P. Squasi P. Squasi 1 Hospital Santa Maria di Ca Foncello, Division of Cardiology , Treviso , Italy M. Mastropietro M. Mastropietro 1 Hospital Santa Maria di Ca Foncello, Division of Cardiology , Treviso , Italy A. Tronchin A. Tronchin 2 Biotronik Italia , Milano , Italy D. Giacopelli D. Giacopelli 2 Biotronik Italia , Milano , Italy Z. Olivari Z. Olivari 1 Hospital Santa Maria di Ca Foncello, Division of Cardiology , Treviso , Italy Abstract Purpose: To retrospectively evaluate either the detection and the management of atrial high rate episodes in patients without history of atrial tachyarrhythmias implanted with a single lead implantable cardioverter defibrillator (ICD) able of atrial sensing. Methods: From July 2010 to November 2014, 29 patients (mean age 60.3 ± 10.1 years, 96% males) with no documented atrial arrhythmic episodes and with no symptoms attributable to them were implanted with a single lead ICD with atrial sensor (DX system, Biotronik). The indication was primary prevention for 24 (83%) and secondary one for 5 (17%); the mean left ejection fraction was 34 [range: 25-65] %. β-blockers, antiplatelet drugs, diuretics, ACE inhibitors, antiarrhythmic drugs, and anticoagulants were present in 93%, 86%, 83%, 69%, 14%, and 7% of the patients therapies respectively. The median follow up period was 21.2 months [IQR 12.4-34.3]. A per-patient analysis of the atrial high rate episodes and of the resulting clinical interventions was performed. Results: The mean atrial sensing of the DX system was 4.6 ± 2.6 mV. Atrial high rate episodes detected by the devices occurred in 5 (17.2%) patients. Among them four patients were asymptomatic. The mean ventricular response during the arrhythmic episodes was 91.6 [range: 50 - 135] bpm. In three patients phone contact was performed only, with no further action. Two patients had an unscheduled ambulatory visit; antiarrhythmic and anticoagulant drugs were introduced in their therapy. The mean duration of the arrhythmic episodes in the four subjects who had a single event was 9.4 [range: 1 - 29] hours. The remaining patient experienced several episodes with increasing extent until persistent atrial arrhythmia. The reaction time to the remote alerts was < 24 hours in the 40% of the cases and between 24 and 48 hours in the 60%. Conclusions: The addition of an atrial sensor in the single lead ICD may unmask asymptomatic atrial arrhythmic episodes; and together with remote monitoring it may allow prompt patients management. Controlled studies are needed to evaluate if such early reactions may improve patient's clinical outcome. P862 The impact of age on clinical outcomes patients with primary prevention ICD/CRT-Ds A. Yue A. Yue P.R. Roberts P.R. Roberts P.J. Roderick P.J. Roderick J.M. Morgan J.M. Morgan University Hospital Southampton NHS Foundation Trust , Southampton , United Kingdom D.G. Wilson D.G. Wilson H.M. Zeljko H.M. Zeljko G. Leventopoulos G. Leventopoulos Abstract Purpose: To evaluate the impact of increasing age on the clinical outcomes from primary prevention ICD/CRT-D population. Methods: Patients with ICD /CRT-D devices implants primary prevention indications were identified from a retrospective analysis of a single centre ICD database (Medtronic Paceart system 3rd edition) from 1st January 2006 to 1st November 2014. Clinical outcomes defined as: survival to follow up with no therapy (T1), death prior to follow up with no therapy (T2), delivery of appropriate (life-prolonging) therapy with survival to follow up (T3) and delivery of appropriate (life-prolonging) therapy with death prior to follow up (T4). Patients were categorised in to deciles (D) of age according to their age at device implant or replacement (60-69.9 years (D1), 70-79.9 years (D2) and >80 years old (D3)). Life prolonging therapy was defined any ATP/shock delivered for a ventricular arrhythmia with cycle 300ms or less (≥200 beats per minute). Results: In total 349 primary prevention cases were analysed (D1=128, D2=174, D3=47) Overall, 85.7% were male, 73.8% were of ischaemic aetiology and 19.7% generator exchange. Median follow up time was 31.3 months for D1, 41.6 months for D2 and 28.6 months for D3. No significant differences between groups was observed for device type with 65.3% CRT-D. As deciles increased T1 decreased significantly (71.9% versus 58.1% for D1 versus D2 (p=0.019) and 71.9% versus 53.2% for D1 versus D3 P=0.03) and T2 increased 9.4% versus 13.2 for D1 versus D2 (P=0.4) and 9.4% versus 21.3% for D1 versus D3 p=0.04). However as deciles increased, there was no significant difference in the proportion of those who received potentially life-prolonging therapy, 10.9% versus 12.1% for D1 versus D2 (p=0.9) and 10.9% versus 10.6% for D1 versus D3 (p=0.95). Furthermore, the risk of dying for those who received potentially life-prolonging therapy increases with age, from the D1 to D2 (HR 1.353 95% CI 0.748-2.4447 P=0.317) and from D1 to D3 (HR 2.415 95% CI 1.156-5.043 P=0.19). The mean time to survival of survival after potentially life prolonging therapy was 23.3 months for D1, 39.2 months for D2 and 16.9 months for D3. Conclusion: Increasing age does not reduce the proportion of patients receiving potentially appropriate therapy for primary prevention of sudden cardiac death. Increasing age is associated with a significant increase in the proportion of patients who die without receiving life-prolonging therapy prior to follow up. These data are useful for improving clinical decision making in elderly patients who meet primary prevention ICD implant criteria. P863 Defibrillator patients should not be denied a peaceful death A. Kinch Westerdahl A. Kinch Westerdahl 1 Karolinska Institute, Danderyd Hospital, Department of Clinical Sciences , Stockholm , Sweden R.S. Sutton R.S. Sutton 2 Imperial College London , London , United Kingdom V.F. Frykman V.F. Frykman 1 Karolinska Institute, Danderyd Hospital, Department of Clinical Sciences , Stockholm , Sweden Abstract Aim: To investigate end of life in ICD patients, with respect to location of death; duration between Do-not-resuscitate-orders (DNR) and deactivation of Implantable Cardioverter Defibrillator (ICD) therapy or DNR and time of death. Methods and Results: A descriptive analysis of 65 deceased ICD patients, all whom had a written DNR-order before death, is presented. The majority (86%) was treated in hospitals, mainly (63%) university hospitals, and many (33%) in cardiology wards. Despite DNR-order, ICD shock therapy was active in 51% of all patients. In those with therapy deactivated at death, therapy deactivation was carried out 2 days or more after DNR-order in more than a third (38%). The time from DNR decision to death in patients with therapy active had a median of 4 days (IQR 1-38). During the last 24h of life 24% of the patients experienced shock treatment. Conclusions: The majority of ICD patients with a DNR-order were treated in university hospitals. More than half still had shock treatment active at time of death with a median of 4 days or more between decision of DNR and death. Patients with therapy deactivated, 2 days or more elapsed in more than a third from the DNR decision to deactivate therapy, exposing patients to a high risk of painful shocks before death. Table 1. ICD therapy programmed ON or OFF in different locations (n=65) Table 1 ICD Therapy All n=65 Medicine* n=25 Cardiology n= 16 Geriatrics n= 4 Surgical n=3 Hospice (4) Nursing Home (4)n=8 Home (8)Not known (1)n=9 ICD ON 24h 42(65) 15(60) 12(75) 2(50) 3(100) 5(63) 5(56) ICD ON 1h 33(51) 10(40) 9(56) 2(50) 2(67) 5(63) 5(56) ICD OFF 1h 28(43) 13(52) 5(32) 2(50) 1(33) 3(38) 4(44) Magnet 4(6) 2(8) 2(13) 0 0 0 0 Shock† 10(24) 5(33) 2(13) 1(25) 1(33) 1(13) 0§  ICD Therapy All n=65 Medicine* n=25 Cardiology n= 16 Geriatrics n= 4 Surgical n=3 Hospice (4) Nursing Home (4)n=8 Home (8)Not known (1)n=9 ICD ON 24h 42(65) 15(60) 12(75) 2(50) 3(100) 5(63) 5(56) ICD ON 1h 33(51) 10(40) 9(56) 2(50) 2(67) 5(63) 5(56) ICD OFF 1h 28(43) 13(52) 5(32) 2(50) 1(33) 3(38) 4(44) Magnet 4(6) 2(8) 2(13) 0 0 0 0 Shock† 10(24) 5(33) 2(13) 1(25) 1(33) 1(13) 0§  Table 1 ICD Therapy All n=65 Medicine* n=25 Cardiology n= 16 Geriatrics n= 4 Surgical n=3 Hospice (4) Nursing Home (4)n=8 Home (8)Not known (1)n=9 ICD ON 24h 42(65) 15(60) 12(75) 2(50) 3(100) 5(63) 5(56) ICD ON 1h 33(51) 10(40) 9(56) 2(50) 2(67) 5(63) 5(56) ICD OFF 1h 28(43) 13(52) 5(32) 2(50) 1(33) 3(38) 4(44) Magnet 4(6) 2(8) 2(13) 0 0 0 0 Shock† 10(24) 5(33) 2(13) 1(25) 1(33) 1(13) 0§  ICD Therapy All n=65 Medicine* n=25 Cardiology n= 16 Geriatrics n= 4 Surgical n=3 Hospice (4) Nursing Home (4)n=8 Home (8)Not known (1)n=9 ICD ON 24h 42(65) 15(60) 12(75) 2(50) 3(100) 5(63) 5(56) ICD ON 1h 33(51) 10(40) 9(56) 2(50) 2(67) 5(63) 5(56) ICD OFF 1h 28(43) 13(52) 5(32) 2(50) 1(33) 3(38) 4(44) Magnet 4(6) 2(8) 2(13) 0 0 0 0 Shock† 10(24) 5(33) 2(13) 1(25) 1(33) 1(13) 0§  P865 The subcutaneous implantable cardioverter-defibrillator: first single-center experience with concomitant implantable pulse generators J. Kuschyk J. Kuschyk K. Stach K. Stach E. Tulumen E. Tulumen B. Rudic B. Rudic V. Liebe V. Liebe R. Schimpf R. Schimpf M. Borggrefe M. Borggrefe S. Roeger S. Roeger University Medical Center Mannheim, 1st Medical Department , Mannheim , Germany Abstract Background: Subcutaneous implantable cardioverter-defibrillator (S-ICD) is a device for antiarrhythmic therapy with no intravascular leads. The S-ICD does not have pacing functions. We describe the technical feasibility of combining the S-ICD with other implantable pulse generators (IPGs), including pacemakers with trans-venous or epicardial electrodes. For the first time, we describe how S-ICD can also co-work successfully with cardiac contractility modulation (CCM) and with vagus nerve stimulation (VNS). Methods: Between 7/2011 and 11/2014 six patients had S-ICD in combination with CCM, three patients with single-chamber pacemakers with trans-venous or epicardial pacing electrodes received S-ICD, and one S-ICD patient received VNS. In all patients intraoperative S-ICD testing, crosstalk tests and postoperative ergometer testing were performed. Results: In all 10 patients device implantations were successfully performed without complications. S-ICD therapy was shown to be technically feasible with concomitant IPGs including CCM, pacemaker and VNS. Mean follow up was nearly 17 months (in CCM 5 cases had up to 35 months of follow-up, mean 20.4 months). S-ICD testing and crosstalk check before and during exercise enable successful programming of the S-ICD for proper functioning with concomitant IPG. None of the devices had to be permanently inactivated and no patient received inadequate shock. Conclusions: In select patients, S-ICD can be combined with a pacemaker. Combination of a S-ICD with CCM and with VNS may be practical for reducing the number of trans-vascular leads. S-ICD appeared safe with CCM over a long follow-up period. Additional reports on S- ICD co-work with IPGs are warranted. P866 Defibrillation testing for right-sided implantable cardioverter-defibrillators (ICD) S. Venier S. Venier P. Khairy P. Khairy M. Dubuc M. Dubuc K. Dyrda K. Dyrda P. Guerra P. Guerra L. Rivard L. Rivard D. Roy D. Roy M. Talajic M. Talajic L. Macle L. Macle B. Thibault B. Thibault Montreal Heart Institute, Electrophysiology , Montreal , Canada Abstract Purpose: For standard left-sided ICDs, defibrillation testing (DT) by ventricular fibrillation induction was recently shown not to improve ICD shock efficacy or reduce mortality. It remains to be determined whether these results can be extrapolated to right-sided ICDs. Methods: We assessed the prevalence of failed DT and the association between DT, shock efficacy, and survival in a retrospective cohort of patients with right-sided ICDs implanted between July 2004 and July 2014. Results: A total of 176 patients, age 63±13 years, 74% male were included. The average left ventricular ejection fraction (LVEF) was 32±13%, with ischemic cardiomyopathy in 52%. ICDs (VVI 44%; DDD 19%; CRT 37%) were implanted for primary prevention in 52%. DT was performed in 124 (70%) patients, 32 (25%) of whom failed their first shock at 24±5 J. The only factor independently associated with test failure was a lower LVEF [OR 0.95, 95% CI (0.92-0.99)]. At 43±32 months of follow-up, 6 patients had appropriate ICD shocks, 2 of whom had failed DTs at implant. Only 1 shock failure was observed during follow-up, occurring in a patient who failed DT at implant (he subsequently survived). DT was not predictive of shock efficacy. Overall survival rates were similar in patients with or without DT (p=0.57) and whether or not the first DT shock was successful (p=0.77). Conclusion: The first attempt at DT fails in a high proportion (25%) of right-sided implants. Nevertheless, DT failure and lack of DT were not associated with future shock efficacy or overall survival. These results challenge the pertinence of routine DT in patients with right-sided ICDs and underscore the need for a randomized prospective controlled trial. Survival probability DT vs NoDT P867 Electromagnetic interference between smartphones and current cardiac implantable electronic devices: rare but present C. Lennerz C. Lennerz 1 German Heart Center, Clinic for Heart and Circulatory Diseases , Munich , Germany H. Pavaci H. Pavaci 2 Hospital Landshut-Achdorf, Department of Internal Medicine I, Cardiology , Landshut-Achdorf , Germany C. Grebmer C. Grebmer 1 German Heart Center, Clinic for Heart and Circulatory Diseases , Munich , Germany H. Vrazic H. Vrazic 3 University Hospital Dubrava, Department of Internal Medicine, Cardiology , Zagreb , Croatia V. Semmler V. Semmler 1 German Heart Center, Clinic for Heart and Circulatory Diseases , Munich , Germany M. Kottmaier M. Kottmaier 1 German Heart Center, Clinic for Heart and Circulatory Diseases , Munich , Germany M. Kornmayer M. Kornmayer 1 German Heart Center, Clinic for Heart and Circulatory Diseases , Munich , Germany G. Von Olshausen G. Von Olshausen 1 German Heart Center, Clinic for Heart and Circulatory Diseases , Munich , Germany I. Deisenhofer I. Deisenhofer 1 German Heart Center, Clinic for Heart and Circulatory Diseases , Munich , Germany C. Kolb C. Kolb 1 German Heart Center, Clinic for Heart and Circulatory Diseases , Munich , Germany Abstract Purpose: Patients with cardiac implantable electronic devices (CIED) are advised to keep a safety distance between conventional mobile phones and their CIED as electromagnetic interference (EMI) may occur. This recommendation is derived from pacemaker studies performed more than a decade ago. The aim of the study is to assess potential EMI between modern smartphones applying the current mobile network standards (GMS, UMTS, LTE) and modern CIED including ICD- and CRT-systems. Methods: All patients visiting the outpatient clinic were eligible for this prospective, cross sectional study. The only exclusion criteria were lead malfunction or battery depletion. After CIED interrogation, the base rate or the atrio-ventricular delay was adjusted to achieve permanent ventricular pacing and shock function was disabled in ICDs. All other CIED parameters were left unchanged. Then all participants were exposed to the electromagnetic field of three commercially available smartphones (Samsung Galaxy 3, Nokia Lumia, HTC One XL). After placing the smartphones directly over the CIED the smartphones connected to a basis mobile network station especially installed for this study. This specific basis ensured that each of the smartphones went through a standardized protocol which included the entire calling process (connecting, ringing, talking), the alternation between all current network standards (GMS, UMTS, LTE where applicable), the operation at maximal transmission power (standard mode) or the modulation of the transmission power in a 50Hz tact (50Hz mode). During all tests a 6 lead ECG was continuously recorded and investigated for potential sensing and pacing abnormalities. CIEDs re-interrogations after the tests were evaluated for a potential re-programming and stored electrograms for inappropriate tachycardia detection. Results: A total of 308 CIED recipients (103 pacemakers, 103 ICDs, 66 CRTs) were included in the study. Through the variation of smartphones, network standards and transmission power modes more than 4000 tests on EMI were performed. One out of 308 patients (0.3%) was affected by EMI caused by smartphones. In this patient ventricular oversensing and atrial oversensing occurred when the MRI compatible ICD was exposed to Nokia or HTC smartphones operating at GSM and UMTS. There was no evidence of EMI using the LTE standard for testing. Conclusions: EMI between smartphones and CIEDs is an infrequent event with a prevalence of 0.3 %. The recommendation of a safety distance between smartphones is warranted to be maintained. MRI-compatible CIEDs are not protected from EMI caused by smartphones. P868 Pacemaker replacement in nonagenarians: procedural safety and long-term follow-up A. Godot A. Godot D. Feneon D. Feneon A. Behaghel A. Behaghel N. Behar N. Behar A. Le Helloco A. Le Helloco P. Mabo P. Mabo J.C. Daubert J.C. Daubert C. Leclercq C. Leclercq R.P. Martins R.P. Martins University Hospital of Rennes - Hospital Pontchaillou, Department of Cardiology and Vascular Disease , Rennes , France Abstract Purpose: The rate of pacemaker (PM) implantations is continuously growing. Given that life-expectancy of the population is projected to increase, a large number of elderly patients is expected to be implanted in the future. Since PM batteries can last as long as 8-10 years, an increasing number of PM recipients will require replacement of their devices while being nonagenarians. We aimed at analyzing the short and long-term outcome after PM replacement in nonagenarians. Methods: Patients aged ≥90 yo referred to a tertiary centre for PM replacement from January 2004 to July 2014 were retrospectively included. The primary clinical endpoint was total mortality. Secondary endpoints included early and delayed-procedure related complications, and predictive risk factors of total mortality. Results: 62 patients were included (93.3±2.9yo at the time of PM replacement). Duration of the procedures was 35.7±17.2 min. Mean hospital stay was 2.2±1.1 days. One patient died from a peri-operative complication. During the follow-up, 37 patients (59.7%) died. Survival rates were 84.2% (95%CI:71.8-91.5%), 66.9% (95%CI:51.8-78.2%) and 22.7% (95%CI:10.6-37.7%) after 1, 2 and 5 years, respectively. Atrial fibrillation (OR 2.44, 95%CI:1.07-5.58) and non-physiological pacing, i.e. VVI pacing in patients in sinus rhythm (OR 2.52, 95%CI:1.12-5.65) were independent predictors of mortality. Conclusions: PM replacement in nonagenarians is a safe and straightforward procedure. These data suggest that procedures can securely be performed in this old and frail population, patients living for a median time of 30 months after the replacement. Atrial fibrillation and non-physiological pacing were independent predictors of mortality. P869 Determining the safety of magnetic resonance imaging in cardiac pacemaker patients, results from the Infinite MRI study V.F. Van Dijk V.F. Van Dijk 1 St Antonius Hospital, Department of Cardiology , Nieuwegein , Netherlands P.P.H.M. Delnoy P.P.H.M. Delnoy 2 Isala Clinics , Zwolle , Netherlands J.J.J. Smit J.J.J. Smit 2 Isala Clinics , Zwolle , Netherlands A.R. Ramdat Missier A.R. Ramdat Missier 2 Isala Clinics , Zwolle , Netherlands A. Elvan A. Elvan 2 Isala Clinics , Zwolle , Netherlands H.W. Van Es H.W. Van Es 3 St Antonius Hospital , Nieuwegein , Netherlands B.J.W.M. Rensing B.J.W.M. Rensing 1 St Antonius Hospital, Department of Cardiology , Nieuwegein , Netherlands L.V.A. Boersma L.V.A. Boersma 1 St Antonius Hospital, Department of Cardiology , Nieuwegein , Netherlands Abstract Purpose: Magnetic Resonance Imaging (MRI) is considered a growing clinical need in many patients with cardiac devices. In the past, pacemakers (PM) had been considered a contraindication to MRI. New generations of MRI conditional pacing systems have been deemed safe if a set of specific conditions for the radiology parameters, device settings and patient conditions are verified during the scan. INFINITE-MRI is a prospective study designed to collect data on the ImageReady System when undergoing an MRI scan under the labeled conditions of use. Methods: All enrolled patients, with the ImageReady MR Conditional Pacing System implanted, underwent an MRI scan with device interrogation and lead measurements done within one hour before and after the scan. Enrolled subjects were required to undergo one follow-up visit within 1 month afer the MRI visit. Results: There were no adverse effects related to the pacemaker or the MRI scan in the study. Lead measurements taken at MRI visit within a narrow timeframe pre and post scan, did not show any clinical relevant change that could indicate an effect of the MRI scan on the device or at the lead-tissue interface(table). Conclusions: The INFINITE MRI study documented safety of the ImageReady MR conditional pacing system in the MRI environment by showing no adverse events related to device or MRI scan. Lead measurements Lead Measurement  Pre-MRI Measurement Post-MRI Measurement One Month Follow-up Measurement Change in Measurements Post-Pre Change in Measurements 1m-Pre  N 14 14 14 14 14 RA Amplitude (mV) Mean ± SD 4.60 ± 1.88 4.16 ± 1.77 4.94 ± 2.29 -0.44 ± 1.73 0.34 ± 1.30  P-Value    0.36 0.34 RA Impedance (ohms) Mean ± SD 472.0 ± 50.2 434.1 ± 39.6 469.4 ± 47.1 -37.9 ± 20.1 -2.6 ± 34.3  P-Value    < 0.001 0.78 RA Threshold (V) Mean ± SD 0.56 ± 0.22 0.53 ± 0.19 0.65 ± 0.18 -0.03 ± 0.11 0.09 ± 0.16  P-Value    0.46 0.053 RV Amplitude (mV) Mean ± SD 16.53 ± 4.45 17.40 ± 4.39 16.14 ± 4.83 0.47 ± 2.09 -0.65 ± 2.61  P-Value    0.41 0.39 RV Impedance (ohms) Mean ± SD 537.9 ± 68.1 517.3 ± 64.6 523.1 ± 65.9 -20.7 ± 16.0 -14.8 ± 17.9  P-Value    < 0.001 0.005 RV Threshold (V) Mean ± SD 0.47 ± 0.11 0.48 ± 0.16 0.54 ± 0.12 0.01 ± 0.13 0.08 ± 0.07  P-Value    0.71 < 0.001  Lead Measurement  Pre-MRI Measurement Post-MRI Measurement One Month Follow-up Measurement Change in Measurements Post-Pre Change in Measurements 1m-Pre  N 14 14 14 14 14 RA Amplitude (mV) Mean ± SD 4.60 ± 1.88 4.16 ± 1.77 4.94 ± 2.29 -0.44 ± 1.73 0.34 ± 1.30  P-Value    0.36 0.34 RA Impedance (ohms) Mean ± SD 472.0 ± 50.2 434.1 ± 39.6 469.4 ± 47.1 -37.9 ± 20.1 -2.6 ± 34.3  P-Value    < 0.001 0.78 RA Threshold (V) Mean ± SD 0.56 ± 0.22 0.53 ± 0.19 0.65 ± 0.18 -0.03 ± 0.11 0.09 ± 0.16  P-Value    0.46 0.053 RV Amplitude (mV) Mean ± SD 16.53 ± 4.45 17.40 ± 4.39 16.14 ± 4.83 0.47 ± 2.09 -0.65 ± 2.61  P-Value    0.41 0.39 RV Impedance (ohms) Mean ± SD 537.9 ± 68.1 517.3 ± 64.6 523.1 ± 65.9 -20.7 ± 16.0 -14.8 ± 17.9  P-Value    < 0.001 0.005 RV Threshold (V) Mean ± SD 0.47 ± 0.11 0.48 ± 0.16 0.54 ± 0.12 0.01 ± 0.13 0.08 ± 0.07  P-Value    0.71 < 0.001  Lead measurements Lead Measurement  Pre-MRI Measurement Post-MRI Measurement One Month Follow-up Measurement Change in Measurements Post-Pre Change in Measurements 1m-Pre  N 14 14 14 14 14 RA Amplitude (mV) Mean ± SD 4.60 ± 1.88 4.16 ± 1.77 4.94 ± 2.29 -0.44 ± 1.73 0.34 ± 1.30  P-Value    0.36 0.34 RA Impedance (ohms) Mean ± SD 472.0 ± 50.2 434.1 ± 39.6 469.4 ± 47.1 -37.9 ± 20.1 -2.6 ± 34.3  P-Value    < 0.001 0.78 RA Threshold (V) Mean ± SD 0.56 ± 0.22 0.53 ± 0.19 0.65 ± 0.18 -0.03 ± 0.11 0.09 ± 0.16  P-Value    0.46 0.053 RV Amplitude (mV) Mean ± SD 16.53 ± 4.45 17.40 ± 4.39 16.14 ± 4.83 0.47 ± 2.09 -0.65 ± 2.61  P-Value    0.41 0.39 RV Impedance (ohms) Mean ± SD 537.9 ± 68.1 517.3 ± 64.6 523.1 ± 65.9 -20.7 ± 16.0 -14.8 ± 17.9  P-Value    < 0.001 0.005 RV Threshold (V) Mean ± SD 0.47 ± 0.11 0.48 ± 0.16 0.54 ± 0.12 0.01 ± 0.13 0.08 ± 0.07  P-Value    0.71 < 0.001  Lead Measurement  Pre-MRI Measurement Post-MRI Measurement One Month Follow-up Measurement Change in Measurements Post-Pre Change in Measurements 1m-Pre  N 14 14 14 14 14 RA Amplitude (mV) Mean ± SD 4.60 ± 1.88 4.16 ± 1.77 4.94 ± 2.29 -0.44 ± 1.73 0.34 ± 1.30  P-Value    0.36 0.34 RA Impedance (ohms) Mean ± SD 472.0 ± 50.2 434.1 ± 39.6 469.4 ± 47.1 -37.9 ± 20.1 -2.6 ± 34.3  P-Value    < 0.001 0.78 RA Threshold (V) Mean ± SD 0.56 ± 0.22 0.53 ± 0.19 0.65 ± 0.18 -0.03 ± 0.11 0.09 ± 0.16  P-Value    0.46 0.053 RV Amplitude (mV) Mean ± SD 16.53 ± 4.45 17.40 ± 4.39 16.14 ± 4.83 0.47 ± 2.09 -0.65 ± 2.61  P-Value    0.41 0.39 RV Impedance (ohms) Mean ± SD 537.9 ± 68.1 517.3 ± 64.6 523.1 ± 65.9 -20.7 ± 16.0 -14.8 ± 17.9  P-Value    < 0.001 0.005 RV Threshold (V) Mean ± SD 0.47 ± 0.11 0.48 ± 0.16 0.54 ± 0.12 0.01 ± 0.13 0.08 ± 0.07  P-Value    0.71 < 0.001  P870 The evaluation of tricuspid regurgitation following implantation of right ventricular septal and apex pacing leads by 3D echocardiography T. Hirai T. Hirai T. Nakagomi T. Nakagomi K. Mamiya K. Mamiya K. Okamoto K. Okamoto K. Iwase K. Iwase M. Niwa M. Niwa K. Miki K. Miki N. Suzuki N. Suzuki T. Tanaka T. Tanaka Okazaki City Hospital , Okazaki , Japan Abstract Background: Right ventricular leads used with implantable cardiac pacemakers or defibrillators are reportedly a risk factor for tricuspid regurgitation (TR). TR caused by a right ventricular lead is usually managed through follow-up care until the condition becomes severe, and surgical outcomes are unfavorable. Although, with conventional 2D echocardiography, it is difficult to depict the link between a lead and the tricuspid valve, 3D echocardiography allows more detailed examination to be performed, resulting in the publication of many studies. However, the link between a right ventricular septal pacing lead and the tricuspid valve has not been investigated. Purpose: We examined position of the right ventricular septal pacing lead passing through the tricuspid valve and the severity of TR using 3D echocardiography and compared with the right ventricular apex pacing. Methods: The subjects were 71 patients aged ≤80 years managed at our pacemaker clinic. The right ventricular septal pacing group was 49 (RVS) and the apex pacing group was 22 (RVA). In all patents, 3D echocardiographic images were acquired. Results: In the RVS group and RVA group, the mean age was 72.1±4.4/71.2±4.1 years; mean duration of follow-up, 45.6±25.8 /154.6±35.3 months; and mean ejection fraction, 62.4±8.1%/61.2±6.5%, respectively. In the RVS group, the position of the pacing lead passing through the tricuspid valve, as depicted by 3D echocardiography, was the anterior-septal commissure in 23 cases, central part of tricuspid valve in 10, posterior-septal commissure and central part in 10 and anterior-posterior commissure in 6 in the RVS group. In the RVA group, the position was the anterior-posterior commissure in 10 cases, central part of tricuspid valve in 10, anterior-septal commissure in 4 and posterior-septal commissure in 1. TR severity was trivial in 22/10 cases, mild in 25/7, mild-to-moderate in 2/3, moderate in 0/2, severe in 0/0. In the RVS group, none had over moderate TR. Discussion: In this study, the right ventricular septal pacing lead was inserted through the anterior and central part of the tricuspid valve in many of our cases compared with apex pacing, and none had over moderate TR. This would suggest a small impact of right ventricular septal pacing on TR. Further research with a larger sample size and longer follow-up is warranted. P871 Activation of coagulation cascade in patients with implantable devices M. Sepsi M. Sepsi 1 University Hospital Brno, Faculty of Medicine, Department of Internal Medicine and Cardiology , Brno , Czech Republic P. Scheer P. Scheer 2 Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences Brno, Department of Physiology , Brno , Czech Republic G. Chlupova G. Chlupova 3 University Hospital Brno, Department of Clinical Hematology , Brno , Czech Republic T. Novakova T. Novakova 1 University Hospital Brno, Faculty of Medicine, Department of Internal Medicine and Cardiology , Brno , Czech Republic J. Spinar J. Spinar 1 University Hospital Brno, Faculty of Medicine, Department of Internal Medicine and Cardiology , Brno , Czech Republic Abstract Aim of the study is to verify whether presence of implanted electrode leads to the change of markers of haemocoagulation. Methods: Patients implanted at our Department with pacemaker (PM) or implantable cardioverter defibrillator (ICD) were included in the study. Before implantation we assessed basic coagulation parameters together with D-dimers (DD), soluble fibrin monomers (SFM) and Thrombin generation assay (TGA). The same parameters were assesed in one month after implantation. Because selected parameters exhibit inter-individual variability, we followed changes over 1 month. Results: From 1.9.2013 till 30.11.2014 we included 342 patients in our study. In further analysis we included 264 patients with unchanged medication before and 1 month after implantation. 181 males, 83 females, age 71 (54 -87), medication: no specific anticoagulation or antithrombotic medication were present in 82 pts (31.1%) , acetylsalicylic acid (ASA) in 91 pts (34.5%). Vitamin K Antagonists (VKA) in 64 pts (24.2%) and other medications in 27 pts (10.2%). Fibrinogen remained in all groups unchanged. D-dimers: there was significant increase in DD in patients treated with ASA (0.6 to 1.1) and in group with no medication (0.5 to 0,9), the DD in patients treated with VKA (0.4 to 0.4) and other medications (0.4 to 0.9) remained unchanged. Soluble fibrin monomers 1 month after implantation were higher in group treated with ASA (1.4 to 4, p=<0,001) and in group with no medication (1.6 to 3.1, p=0,19), in other groups remained SFM unchanged. TGA - thrombin generation was significantly lower in VKA group (TGA AUC changed from 1235.7 to 559.5, p <0,001), in group with no medication was TGA - AUC changed (1896.3 to 1807.7, p=0,011), but in ASA group there was no significant change (1865.9 to 1849.4, p=0,439). Conclusion: In patients after implantation of electrode treated with acetylsalicylic acid or no specific medications, there is increasing in haematological markers of thrombi formation. In patients treated with vitamin K antagonist, markers of thrombi formation remains unchanged. P872 Long-term follow-up of transvenous cardiac pacing in children: single-center experience in 161 patients B. Kircanski B. Kircanski N. Radovanovic N. Radovanovic P. Stojanov P. Stojanov Clinical Center of Serbia, Pacemaker Center , Belgrade , Serbia Abstract Purpose: The purpose of this study was to show that cephalic vein cutdown technique for endovenous lead implantation in children is reliable technique with low complication incidence and could be used as technique of choice for pacemaker lead implantation even in the smallest children. Methods: The study included 161 children with endovenous antibradycardia pacemakers. Implantations were performed from December 1986 to December 2012. The preferred lead implantation technique was cephalic vein cutdown. If the lead implantation was not possible using this technique, we used external jugular vein preparation, axillary vein puncture and finally subclavian vein puncture technique (using this order of preference). When making this order, we were guided by the facts that preparation technique means less surgical trauma and also that axillary vein puncture is better than subclavian vein puncture if we want to avoid lead damaging by costo-clavicular pincer. In children weighing ≤10kg, cephalic, subclavian and axillary vein diameters were measured by ultrasound prior to implantation. Measured diameters were used to make a choice of the surgical technique. First follow-up visit was 1 month after implantation and after that on each 6 months. Results: One (0.6%) AAI, 5(3.1%) VDD, 35(21.8%) DDD, 120(74,5%) VVI pacemakers were implanted. Indications for pacing were complete AV block in 154(95.7%), sinus node disfunction in 6 (3.7%) children and trifascicular block with syncope in 1(0.6%) child. Mean age at implantation was 6.0 years (1 day – 15.0 years). Forty-three children were ≤10kg in weight at implantation – mean 6.14kg (2.25 – 9.9kg). There were 196 leads implanted on first implantation and 182 (92,9%) of them were implanted using cephalic vein cutdown, 6(3.1%) through prepared external jugular vein, 7 (3.6%) using axillary vein puncture and 1(0.5%) using subclavian vein puncture. Mean follow-up was 9.8 years (3 days – 25.1 years). Only 12 (7.5%) complications were detected – 9 of them were lead complications (2 lead dislodgements, 2 exit blocks, 1 insulator damage, 4 lead fractures), 1 pocket infection, 1 pocket decubitus and 1 cardiac perforation. Partial thrombosis of subclavian vein was detected in 21 (13.0%) children with lumen narrowing up to 30% in 19 of them and 50% to 60% in other 2 children. Conclusion: Low complication incidence during long-term follow-up confirms that cephalic vein cutdown technique for endovenous lead implantation is also feasible and reliable in this specific group of patients, not only in adults where is already considered as the technique of choice. P873 Acute transitory atrio ventricular blockage in African; consider sickle cell anemia P.H. Gacon P.H. Gacon University of Bourgogne, service de cardiologie clinique et interventionelle , DIJON , France Abstract Background: Even though sickle cell disease has a high prevalence amongst the black race and despite its well known potential of microinfarction, there have been only a few reports regarding the acute myocardial damage during vaso-occlusive crisis. The risk of atrio ventricularblock during these crises has never been described in a large survey. Patients and results: Ten patients (six men and four women, mean age 39 years old) were hospitalized for an acute atrio ventricular block. Thepatients were all African or Caribbean natives. Three patients were found with a heterozygous phenotype for hemoglobin S (sickle trait) and sevenwere found with a homozygous phenotype. The most common symptoms were asthenia (10 cases), shortness of breath (8 cases) and acute coronarysyndrome (1 case) (syncope was not reported). Four patients had a second degree atrio ventricular block and six patients had third degree block.The treatment involved bed rest, intravenous hydration, and pain relief with opiates prevention of endocarditis and pneumococcal vaccination . All the cases of atrio ventricular block were only transitoryand none of the patients underwent a pacemaker implantation. P874 Undecided about getting a pacemaker? Take one for a test drive M. Giudici M. Giudici University of Iowa, Cardiology , Iowa City , United States of America Abstract Background: Bradycardia due to sinus or AV nodal disease is commonly a slowly progressive problem over many years. Symptoms are often minimized or felt to be due to aging. Some patients, and even implanters, are ambivalent about proceeding with pacemaker implantation where there may not be clear evidence of benefit. We offer these patients a 2-3 week "test-drive" to allow them to assess the potential benefits of permanent pacemaker implantation. Methods: Over a 45-month period, six patients (3M/3F, aged 40-82 yrs) with sinus bradycardia-4, slow conduction of atrial fibrillation-1, and Mobitz 1 2nd degree AV block-1 underwent percutaneous placement of permanent pacing lead(s) via a subclavian approach into the right atrium-4, right ventricular septum-1, or both-1. The lead(s) was then attached to a non-sterile permanent pacemaker which was sewn to the skin and an occlusive dressing was applied. The device was then programmed to a rate-responsive mode at appropriate heart rates for each patient. After 2-3 weeks, the devices were removed. Results: All six patients subsequently chose to undergo permanent pacemaker placement. There were no complications associated with the initial implantation procedure, the trial period, or device removal. Conclusions: In bradycardic patients who are undecided about pacemaker implantation, a 2-3 week trial with a percutaneously-placed temporary permanent pacemaker allow the patient to experience the clinical impact of pacing therapy and may aid in their decision whether to proceed with the permanent implant. P875 Effect of heart rate on the intrinsic and the ventricular-paced QRS duration I. Chiladakis I. Chiladakis A. Kalogeropoulos A. Kalogeropoulos F. Zagkli F. Zagkli K. Chouchoulis K. Chouchoulis University Hospital , Patras , Greece Abstract Background: The QRS duration may be affected by pacing-induced changes in heart rate. We evaluated the effect of heart rate on the intrinsic and the ventricular-paced QRS duration in implanted device recipients with normal or reduced left ventricular ejection fraction (EF). Methods: We studied 239 outpatients with preserved intrinsic ventricular activation and normal (n=92) or reduced (n=147) EF who had the right ventricular lead positioned in apex (RVA) or in mid-septum (RVS). Patients were stratified according to their underlying EF as well as to their baseline narrow or wide QRS complex. The QRS duration was measured at baseline and during atrial-based pacing at 100 beats/min with long or short atrioventricular delay to ensure intrinsic or ventricular-paced QRS activation. Results: At baseline, patients with normal EF compared to those with reduced EF had shorter intrinsic both narrow and wide QRS (P<0.05), whereas ventricular pacing increased the QRS duration in both normal and reduced EF patients with either narrow or wide QRS (P<0.001). The increase in heart rate shortened the intrinsic QRS only in patients with normal EF, and further increased the ventricular-paced QRS duration particularly in patients with reduced EF and either narrow or wide QRS (P<0.001), irrespective of RVA or RVS pacing (P<0.01); ROC curves demonstrated that following heart rate increase, assessment of intrinsic or ventricular-paced ΔQRS may be useful to predict patients with reduced EF. Conclusion: Heart rate increase is associated with further QRS prolongation in patients with reduced EF, regardless of the baseline intrinsic QRS duration as well as of the right ventricular RVA or RVS pacing site. P876 Electromechanical characterization of left ventricular pacing vectors in CRT L. Lambrakos L. Lambrakos 1 Columbia University Medical Center , New York , United States of America E. Bunting E. Bunting 2 Columbia University , New York , United States of America H. Garan H. Garan 1 Columbia University Medical Center , New York , United States of America E. Konofagou E. Konofagou 2 Columbia University , New York , United States of America Abstract Purpose: Recent advancements in CRT pacing lead technology allowing for the implementation of multiple pacing vectors have created an avenue for "patient-specific" CRT optimization. Concurrently, alternative measures of dyssynchrony to assess CRT response are being investigated. One such technique, electromechanical wave imaging (EWI) is an ultrasound-based method that noninvasively estimates cardiac strains at high spatial (< 1mm) and temporal (2000 Hz) resolutions simultaneously. EWI strains can then be used to generate electromechanical activation maps, which have been validated in simulations, animal models, and patients. Methods: CRT patients (n=8) were recruited during their routine device interrogations at Columbia University Medical Center. High framerate ultrasound acquisitions were obtained for each patient in the apical 4- and 2-chamber views in native rhythm and under a variety of pacing protocols, including unipolar, bipolar, and extended bipolar pacing vectors. 12-lead ECG measurements were taken for each pacing configuration following the ultrasound acquisition. Inter-frame strains were estimated from the acquired radiofrequency data for the entire view over a full cardiac cycle. Electromechanical activation times for each point in the tissue were automatically calculated from the strain images using a zero-crossing detection algorithm. A quantitative parameter, lateral wall activation time (LWAT), was computed using the average activation time of the lateral wall in the 4-chamber view. Results: Compared to healthy controls, heart failure patients in native rhythm showed delayed electromechanical activation in the lateral wall, exhibited by a 50.0±20.0 ms increase in LWAT. Selection of pacing vector was also shown to have an impact on the electromechanical activation LWAT within individual patients. Changing the pacing configuration resulted in an average LWAT difference of 27.0±13.2 ms per patient. Furthermore, qualitative analysis of EWI activation maps indicated that distinct spatial and temporal patterns of LV activation were obtained using different pacing vectors. Conclusions: EWI was hereby shown to be capable of imaging the electromechanical activation sequences of CRT patients, including differences that arise when the pacing vector is changed. As such, this study has demonstrated the importance of the LV pacing vector in determining the electromechanical activation sequence. Thus, pacing vector selection will be an interesting area of future study, especially if improvements in clinical end-points can be reached, and may suggest new approaches for CRT monitoring and follow-up. P877 Feature-tracking cardiovascular magnetic resonance to predict response following cardiac resynchronisation therapy R.J. Taylor R.J. Taylor 1 Centre for Cardiovascular Sciences, University of Birmingham, Queen Elizabeth Hospital. , Birmingham , United Kingdom F. Umar F. Umar 1 Centre for Cardiovascular Sciences, University of Birmingham, Queen Elizabeth Hospital. , Birmingham , United Kingdom E.L.S. Lin E.L.S. Lin 1 Centre for Cardiovascular Sciences, University of Birmingham, Queen Elizabeth Hospital. , Birmingham , United Kingdom G. Mankaryous G. Mankaryous 1 Centre for Cardiovascular Sciences, University of Birmingham, Queen Elizabeth Hospital. , Birmingham , United Kingdom B. Stegemann B. Stegemann 2 Bakken Research Center, Medtronic Inc. , Maastricht , Netherlands F. Leyva F. Leyva 1 Centre for Cardiovascular Sciences, University of Birmingham, Queen Elizabeth Hospital. , Birmingham , United Kingdom Abstract Purpose: A panoply of studies have explored the inter- and intra-ventricular mechanical dyssynchrony in relation to response to cardiac resynchronization therapy (CRT). Feature tracking cardiovascular magnetic resonance (FT-CMR), the CMR equivalent of speckle-tracking in echocardiography, allows rapid, semi-automatic assessment of wall motion. We hypothesised that dyssynchrony measures derived from a pre-implant FT-CMR predict response to CRT. Methods: 124 consecutive CRT recipients (age: 67.4 ± 11.2 yrs [mean ±SD]; LVEF: 22.8 ± 9.6% ) underwent pre-implant dyssynchrony assessment for quantification of SD of the time to peak strain (SDT2P), the circumferential uniformity ratio estimate (CURE) and a radial uniformity ratio estimate (RURE). For CURE and RURE, 0 denotes complete dyssynchrony and 1 denotes perfect synchrony. Symptomatic response was defined as freedom from heart failure admissions, improvement by ≥1 NHYA class or by ≥25% increase in 6-min walking distance. A left ventricular (LV) reverse remodeling response was defined as a ≥15% reduction in LVESV at 3 months. Results: SDT2P was higher in symptomatic responders (17% vs. 13%, p = 0.049). As shown in the figure, however, SDT2P, CURE or RURE failed to predict symptomatic or echocardiographic response to CRT. SDT2P was a weak predictor of symptomatic response (ROC: 0.65, 95% C.I. 0.55-0.77; p= 0.007). Conclusions: CURE and RURE, derived from FT-CMR, do not predict response to CRT. ROC's for dyssynchrony parameters P878 Agreement analysis between QuickOpt and echocardiographic-based methods in optimizating cardiac resynchronization therapy devices A. Adel Mohamed Elamragy A. Adel Mohamed Elamragy R.H. Deyab R.H. Deyab H.H. Rizk H.H. Rizk A.M. Abdelwahab A.M. Abdelwahab Cairo University , Cairo , Egypt Abstract Introduction: There is no consensus on the technique of cardiac resynchronization therapy (CRT) optimization of atrioventricular (A-V) and interventricular (V-V) delays. Echocardiography-based optimization (Echo-Opt) -using tissue synchronization imaging modality- is time-consuming and requires experience. The aim of this study was to evaluate the agreement between 2 methods of CRT optimization; QuickOpt (an algorithm-based method) and Echo-Opt. Methods: This prospective crossover study was done on 20 consecutive patients during routine follow up in a University hospital; randomized into 2 groups. Group A and B patients were optimized using QuickOpt and Echo-Opt methods respectively then crossover was done in the next visit. Agreement analysis for continuous variables (optimal A-V delays) was assessed by intraclass correlation coefficient (ICC) and plotting a graph of differences in A-V delay between the 2 methods against their means. Agreement analysis of ordinal data (optimal V-V delays) was done using weighted kappa method. Results: Median time of optimization was significantly lower in QuickOpt compared to Echo-Opt (1.3 vs 26 minutes, p<0.0001). There was a significant learning curve in the Echo-Opt method; optimization time was reduced 0.48 minutes with every subsequent study (95% CI: 0.108-0.865, p= 0.015). There was no agreement between both methods in optimal A-V delays (ICC: 0.26, 95% CI: -0.09 to 0.6) or optimal V-V delays (weighted kappa = 0.16). Conclusion: This was the first study to perform agreement analysis between two different methods of CRT optimization. There was no agreement in optimal A-V and V-V delays using QuickOpt and Echo-Opt. Quick Opt was much faster while Echo-Opt required experience and showed a significant learning curve. Agreement between QuickOpt & Echo-Opt P879 A simple score for predicting CRT-Response based on data from a Multicentric Registry R.A. Providencia R.A. Providencia 1 Clinic Pasteur of Toulouse , Toulouse , France E. Marijon E. Marijon 2 Hôpital Européen Georges Pompidou, Université Paris Descartes , Paris , France A. Bouzeman A. Bouzeman 1 Clinic Pasteur of Toulouse , Toulouse , France P. Defaye P. Defaye 3 University Hospital of Grenoble , Grenoble , France C. Leclercq C. Leclercq 4 Hospital Pontchaillou of Rennes , Rennes , France L. Fauchier L. Fauchier 5 University Hospital of Tours , Tours , France O. Piot O. Piot 6 Centre Cardiologique du Nord (CCN) , Paris , France D. Klug D. Klug 7 CHRU Lille , Lille , France N. Sadoul N. Sadoul 8 University Hospital of Brabois , Nancy , France S. Boveda S. Boveda 1 Clinic Pasteur of Toulouse , Toulouse , France Abstract Introduction: Cardiac resynchronization therapy (CRT) has emerged as a highly effective treatment option in patients with advanced heart failure. Unfortunately, almost tone third of patients do not have any benefit from this therapy. We aimed to derive a CRT response score based on simple clinical and widely validated predictors of response in order to improve the selection of patients for this intervention. Methods: All consecutive patients implanted with a CRT plus defibrillator in a multi-centric national registry were included. Clinical independent predictors of a favourable response to CRT (either clinical or echocardiographic) were assessed. A risk score was created based on the relative odds ratio of each of the variables. The likelihood of CRT response in the different stages was assessed. Results: Among the 1011 patients implanted with a de novo CRT-D, 75.8% were responders. Independent and significant predictors of CRT response in the first 6 months on multivariate logistic regression were: female gender (OR=2.08), New York Heart Association class ≤III (OR=2.71), left ventricle ejection fraction ≥ 25% (OR=1.75), QRS duration ≥ 150ms (OR=1.70) and estimated glomerular filtration rate > 60ml/min (OR=2.01). All predictors were assigned 1 point. The chances of CRT response progressively increased according to the assigned score: 46.7%, 47.9%, 65.9%, 77.7%, 89.5% and 93.9%, respectively from 0 to 5 points. Patients were divided in 3 groups according to the likelihood of response: low (0 or 1 points) 47.7%, intermediate (2 or 3 points) 73.0% and high (4 to 6) 90.0% probability of response to CRT. Likelihood of survival at 6 years was approximately 35% in low response, 60% in intermediate and 80% in the high response group (P log rank <0.001). This score was also a moderate discriminator of patients dying in the first year after the implant. Conclusion: A simple and hypothetically widely used score for optimization of patient selection for CRT therapy was derived from our registry. Association between CRT response and 5 years survival is also suggested from our data. Prospective validation of this score in further populations before its introduction in routine clinical practice is still necessary. P880 targeting the latest activated region is the best strategy for optimizing response to CRT: fact or fiction? M. Pluijmert M. Pluijmert 1 Cardiovascular Research Institute Maastricht (CARIM), Biomedical Engineering , Maastricht , Netherlands J. Lumens J. Lumens 1 Cardiovascular Research Institute Maastricht (CARIM), Biomedical Engineering , Maastricht , Netherlands P. Bovendeerd P. Bovendeerd 2 Eindhoven University of Technology, Biomedical Engineering , Eindhoven , Netherlands K. Vernooy K. Vernooy 3 Maastricht University Medical Centre (MUMC), Cardiology , Maastricht , Netherlands T. Delhaas T. Delhaas 1 Cardiovascular Research Institute Maastricht (CARIM), Biomedical Engineering , Maastricht , Netherlands F. Prinzen F. Prinzen 4 Cardiovascular Research Institute Maastricht (CARIM), Physiology , Maastricht , Netherlands Abstract Cardiac resynchronization therapy (CRT) benefits patients with chronic heart failure and left bundle branch block (LBBB). Position of the left ventricular (LV) pacing lead is considered an important determinant of CRT response, but the underlying mechanism is not completely understood. We used a finite element (FE) model of biventricular (BiV) electro-mechanics to investigate how LV lead position influences hemodynamic response to CRT. Local myocardial activation time (AT) was computed by solving the Eikonal-diffusion equation. Complete LBBB (LBBBc) was simulated by defining Purkinje exit points only at the right ventricular (RV) endocardium, while incomplete LBBB (LBBBi) was simulated by adding one exit point on the posterior LV endocardium. Both cases had a different location of the latest activated region (LAR) during baseline. CRT was simulated as BiV pacing, a fixed-point stimulation in the RV apex combined with stimulation from one of 16 different epicardial LV free wall (LVfw) locations (figure). Computed AT patterns served as input for mechanical simulation of pump function. CRT response was defined as % change in LV dp/dtmax relative to LBBB. Total activation time was 174 ms during LBBBc, and 144 ms during LBBBi. For LBBBc simulation, response to CRT showed a good, but not perfect correlation with AT during baseline of the paced region (panel A), while there was no such correlation for LBBBi simulation (panel B). For both LBBBc and LBBBi, largest response to CRT was obtained when the LV lead was located so that the intra LV dyssynchrony, defined as the difference between mean LVfw AT and mean septal AT, was minimal (panel C). Acute hemodynamic response to BiV pacing is highly determined by resynchronization of activation in the LV. This is not necessarily achieved by pacing the LAR. P881 Effect of stem cell therapy on electrical and mechanical activation in heart failure patients F. Maffessanti F. Maffessanti 1 Universitá della Svizzera italiana, Institute of Computational Science, Center for Computational Medicine in Cardiology , Lugano , Switzerland D. Suerder D. Suerder 2 Cardiocentro Ticino, Division of Cardiology , Lugano , Switzerland W. Kroon W. Kroon 1 Universitá della Svizzera italiana, Institute of Computational Science, Center for Computational Medicine in Cardiology , Lugano , Switzerland M. Potse M. Potse 1 Universitá della Svizzera italiana, Institute of Computational Science, Center for Computational Medicine in Cardiology , Lugano , Switzerland F. Regoli F. Regoli 2 Cardiocentro Ticino, Division of Cardiology , Lugano , Switzerland R. Murzilli R. Murzilli 2 Cardiocentro Ticino, Division of Cardiology , Lugano , Switzerland T. Moccetti T. Moccetti 2 Cardiocentro Ticino, Division of Cardiology , Lugano , Switzerland F.W. Prinzen F.W. Prinzen 3 Cardiovascular Research Institute Maastricht (CARIM), Department of Physiology , Maastricht , Netherlands R. Krause R. Krause 1 Universitá della Svizzera italiana, Institute of Computational Science, Center for Computational Medicine in Cardiology , Lugano , Switzerland A. Auricchio A. Auricchio 2 Cardiocentro Ticino, Division of Cardiology , Lugano , Switzerland Abstract Purpose: We aimed at evaluating the effects of autologous bone marrow mononuclear cell (BMMC) transplantation on electromechanical (EM) coupling in heart failure (HF) patients. Methods: Left ventricular electroanatomical contact maps of 8 patients undergoing 3D mapping using a system targeted for delivery were analyzed. Electroanatomical mapping was performed immediately before and 6 months after BMMC treatment. At each catheter location, unipolar voltages UEG (1kHz) and electrode position (100Hz) were recorded for 2500 ms. Custom software was used to obtain maps of depolarization (TDep) time, activation recovery interval (ARI), time to onset (TOns) and peak of shortening (TPS), local linear shortening (LLS), and EM delay between activation and onset (EMDOns) or peak of shortening (EMDPeak). Dyssynchrony Δ was defined as the time interval between the earliest and latest events. End-diastolic (EDV) and end-systolic volumes (ESV), and ejection fraction (EF) were also computed. The effect of BMMC transplantation was evaluated using a linear mixed model, including the follow-up time step as a fixed factor, while the different patient and the anatomical location of the recording (in terms of AHA segment) were entered as random factors to account for the inter-patient variability and the different spatial distribution of recording locations. Results: Analysis was feasible in all cases. Measurements were taken in 201±71 locations/session. No significant changes were observed for EDV (Median, [Range]; Pre=264ml [127,350] vs Post=270ml [127,393], p=0.80, Wilcoxon test), ESV (206ml [58,264] vs 213ml [78,286], p=0.96), EF (25% [16,54] vs 26% [19,48], p=0.57), ΔTDep (80ms [52,125] vs 91ms [55,129], p=0.65), ΔTOns (143ms [67,265] vs 147ms [126,207], p=0.38) and ΔTPS (147ms [126,207] vs 136ms [100,227], p=0.57). Effects of BMMC (Table): compared to baseline, 6-month voltages were slightly lower, EM delays increased, ARI shortened, Tons and TPS times were delayed while LLS improved. Conclusions: At 6-month follow-up BMCC had no measurable effect on electrical and mechanical activation. Effect of BMMC therapy Variable UEG (mV) ARI (ms) TOns (ms) TPS (ms) EMDOns EMDPeak (ms) LLS (%) Effect -0.3* -10* +13* +18* +13* +18* -1* Pre BMMC 7.9 [7.4,8.3] 350 [342,358] 77 [70,85] 380 [372,387] 82 [77,88] 384 [378,392] -9 [-10,-8] Post BMMC 7.6 [7.1,8.0] 340 [332,348] 90 [82,97] 398 [390,405] 96 [90,101] 403 [396,410] -10 [-11,-9]  Variable UEG (mV) ARI (ms) TOns (ms) TPS (ms) EMDOns EMDPeak (ms) LLS (%) Effect -0.3* -10* +13* +18* +13* +18* -1* Pre BMMC 7.9 [7.4,8.3] 350 [342,358] 77 [70,85] 380 [372,387] 82 [77,88] 384 [378,392] -9 [-10,-8] Post BMMC 7.6 [7.1,8.0] 340 [332,348] 90 [82,97] 398 [390,405] 96 [90,101] 403 [396,410] -10 [-11,-9]  Contrast on Pre BBMC. Values reported as marginal means [95% CI]; *:p<0.01 Effect of BMMC therapy Variable UEG (mV) ARI (ms) TOns (ms) TPS (ms) EMDOns EMDPeak (ms) LLS (%) Effect -0.3* -10* +13* +18* +13* +18* -1* Pre BMMC 7.9 [7.4,8.3] 350 [342,358] 77 [70,85] 380 [372,387] 82 [77,88] 384 [378,392] -9 [-10,-8] Post BMMC 7.6 [7.1,8.0] 340 [332,348] 90 [82,97] 398 [390,405] 96 [90,101] 403 [396,410] -10 [-11,-9]  Variable UEG (mV) ARI (ms) TOns (ms) TPS (ms) EMDOns EMDPeak (ms) LLS (%) Effect -0.3* -10* +13* +18* +13* +18* -1* Pre BMMC 7.9 [7.4,8.3] 350 [342,358] 77 [70,85] 380 [372,387] 82 [77,88] 384 [378,392] -9 [-10,-8] Post BMMC 7.6 [7.1,8.0] 340 [332,348] 90 [82,97] 398 [390,405] 96 [90,101] 403 [396,410] -10 [-11,-9]  Contrast on Pre BBMC. Values reported as marginal means [95% CI]; *:p<0.01 P882 Effects of cardiac resynchronization therapy on functional capacity and neurocognitive profile, a possible role on the slowing of frailty development M. Nesti M. Nesti S. Fumagalli S. Fumagalli L. Pandolfini L. Pandolfini M. Beltrami M. Beltrami G. Ricciardi G. Ricciardi P. Pieragnoli P. Pieragnoli L. Padeletti L. Padeletti Careggi University Hospital (AOUC), Arrhythmology , Florence , Italy Abstract Introduction: Cardiac resynchronization therapy (CRT) proved to significantly reduce hospitalization and mortality in severely diseased heart failure (HF) patients. Despite growing knowledge on the effects of CRT, some physio-pathological implications of this important form of therapy are to be clarified. Aim of this study was to evaluate the influence of CRT on functional and cognitive profile trajectories, which are closely associated with frailty development. Methods: All consecutive patients who received a CRT-P or CRT-D device between June and December 2013 in three Italian centers were enrolled in the study. At baseline and at the 6-month evaluation, functional profile was evaluated with the Short Physical Performance Battery (SPPB), a tool exploring strength, endurance and balance, highly predictive of incident disability and mortality. Cognitive profile was assessed with the Mini-Mental State Examination (MMSE) and with the Trail Making Test (TMT) A and B, which also explore executive functioning. Results: We enrolled 52 consecutive patients (age: 68+10 years, age >75 years: 26.6%; men: 73%) with severely depressed systolic function (LVEF: 28+5%; coronary artery disease: 44%) and optimized medical therapy (ACE-I/ARB: 89%, beta-blockers: 83%). At the 6-month evaluation, mortality was 3.8% (N=2/52) with a proportion of responders to CRT of 61%. LVEF significantly increased (35+7 vs. 28+5%, p<0.0001), while LV end-systolic diameter (48+8 vs. 56+9 mm, p<0.0001) and NYHA Class (1.8+0.7 vs. 2.5+0.6, p<0.0001) reduced. SPPB improved both in its overall score (10.2+2.4 vs. 9.1+2.7, p=0.012) and in scores exploring walking speed (3.5+0.8 vs. 3.1+1.2, p=0.005) and endurance (3.1+1.1 vs. 2.7+1.1, p=0.015). These changes matched with a better cognitive profile, as expressed by a higher MMSE score (27.3+3.0 vs. 26.2+4.6, p=0.009). Times to complete TMT A and TMT B did not change at the follow-up. Conclusions: CRT, through a great improvement in cardiac conditions, significantly ameliorates functional capacity and neurocognitive profile of patients after only 6 months from device implantation. Specifically designed clinical trials are needed to confirm these findings, which suggest a possible action of CRT on the slowing of HF progression from severe disability to death. P883 Triple-site ventricular (TRIV) pacing is superior to conventional biventricular pacing: a prospective observational trial with minimum invasive hemodynamic assessment M. Nobre Menezes M. Nobre Menezes P. Marques P. Marques G. Lima Da Silva G. Lima Da Silva A. Bernardes A. Bernardes A. Magalhaes A. Magalhaes N. Cortez Dias N. Cortez Dias L. Carpinteiro L. Carpinteiro J. De Sousa J. De Sousa F.J. Pinto F.J. Pinto Hospital Lisbon North, Hospital Santa Maria , Lisbon , Portugal Abstract Introduction: Multi-site pacing and multi-point pacing are emerging as new methods of cardiac ressynchronization (CRT). Their efficacy and indications, however, have been scarcely studied so far. The optimal method of ressynchronization also remains unknown. We aim to compare triple site ventricular (TRIV) pacing to conventional biventricular (BiV) pacing. Methods: Prospective observational study of patients with permanent atrial fibrillation with ejection fraction < 40% undergoing CRT implantation. All patients had 3 leads implanted. Two right ventricle (RV) leads were implanted, one in the apex and other in the outflow tract septal wall (RVOT). A left ventricle (LV) lead was implanted in the coronary sinus as usual in a conventional CRT. Within 1 month after implantation, all patients underwent minimally invasive hemodynamic assessment using the Vigileo Flotrac (Edwards Lifesciences) for the determination of cardiac output in each pacing configuration: triple site pacing (TRIV), RV apex-LV, or RVOT-LV. Mean QRS and echocardiogram ejection fraction (using the Simpson biplane method) were also analysed for each configuration. Results: We included 33 patients, 92% male, 73 ± 11 years old. Mean cardiac output and mean QRS width measurements in the three different pacing configurations are showed in table 1. Cardiac output was significantly higher and the QRS width shorter in the TRIV configuration in comparison with both BiV configurations. Mean ejection fraction was 29% with TRIV and 28% with both BiV configurations (p=ns). Conclusion: TRIV pacing is hemodinamically superior to conventional BiV pacing, producing higher cardiac output and shorter QRS duration in patients with atrial fibrillation, LV dysfunction and CRT indication. The echocardiography ejection fraction was not accurate in detecting differences between pacing configurations. Hemodynamic and ECG results  TRIV RVA-LV RVOT-LV P-value TRIV vs. RVA-LV TRIV vs. RVOT-LV RVA-LV vs. RVOT-LV Cardiac Output (L/min) 4,82 ± 1,03 4,67 ± 0,93 4,70 ± 0,93 <0,001 =0,001 NS QRS width (msecs) 122 ± 17,2 147 ± 18 143 ± 24,6 <0,001 <0,001 NS   TRIV RVA-LV RVOT-LV P-value TRIV vs. RVA-LV TRIV vs. RVOT-LV RVA-LV vs. RVOT-LV Cardiac Output (L/min) 4,82 ± 1,03 4,67 ± 0,93 4,70 ± 0,93 <0,001 =0,001 NS QRS width (msecs) 122 ± 17,2 147 ± 18 143 ± 24,6 <0,001 <0,001 NS  Hemodynamic and ECG results Hemodynamic and ECG results  TRIV RVA-LV RVOT-LV P-value TRIV vs. RVA-LV TRIV vs. RVOT-LV RVA-LV vs. RVOT-LV Cardiac Output (L/min) 4,82 ± 1,03 4,67 ± 0,93 4,70 ± 0,93 <0,001 =0,001 NS QRS width (msecs) 122 ± 17,2 147 ± 18 143 ± 24,6 <0,001 <0,001 NS   TRIV RVA-LV RVOT-LV P-value TRIV vs. RVA-LV TRIV vs. RVOT-LV RVA-LV vs. RVOT-LV Cardiac Output (L/min) 4,82 ± 1,03 4,67 ± 0,93 4,70 ± 0,93 <0,001 =0,001 NS QRS width (msecs) 122 ± 17,2 147 ± 18 143 ± 24,6 <0,001 <0,001 NS  Hemodynamic and ECG results P884 Clinical response and reverse remodeling after cardiac resynchronisation therapy in patients with right ventricular dysfunction P. Pinto-Teixeira P. Pinto-Teixeira M. Oliveira M. Oliveira A. Galrinho A. Galrinho P. Cunha P. Cunha L. Branco L. Branco J. Feliciano J. Feliciano R. Pimenta R. Pimenta A. Lousinha A. Lousinha M. Nogueira-Silva M. Nogueira-Silva R. Ferreira R. Ferreira Hospital Santa Marta, Department of Cardiology , Lisbon , Portugal Abstract Purpose: Right ventricular (RV) dysfunction is accepted as a marker of unfavourable prognosis in patients (P) with heart failure (HF). Few data are available on the impact of cardiac resynchronisation therapy (CRT) in P with impairment of RV function. The aim of this study is to evaluate the response to CRT in P with biventricular systolic dysfunction. Methods: From 258 consecutive P who underwent CRT implantation, we identified those with baseline tricuspid annular plane systolic excursion (TAPSE) ≤ 14mm and at least 1 year follow-up. We compared clinical and echocardiographic parameters, which were assessed before, and 6 to 12 months after CRT implantation. We considered clinical response as sustained improvement of at least one NYHA class; left ventricular (LV) reverse remodeling as improvement of LV ejection fraction (LVEF) > 10%, associated with reduction in LV end-diastolic diameter (LVEDD) > 10%; and super-response as an improvement to LVEF > 45% . Results: 26 P with TAPSE ≤ 14mm (63.3±9.6 years, 80% male, 42% ischemic cardiomyopathy, pre-CRT wQRS 182.4±39.8 ms, NYHA class 2.96±0.35) were analyzed during a median follow-up time of 448 days. LVEF improved significantly after CRT (from 24.4±7.3% to 33.2±9.2%; p<0.001), as well as LVEDD (from 73.6±6.6mm to 70.5±7.6mm; p>0.001) and LVESD (from 59.4±8.7mm to 53.7±10.2mm; p=0.015). Accordingly, TAPSE also showed significant increase after CRT (from 12.0±0.4mm to 16.2±0.7mm; p<0.001). Clinical response occurred in 18P (69%), LV reverse remodeling in 11 (42%) and super-response in 6 (23%). During the follow-up time, 1 admission due to HF and 5 deaths of cardiac cause occurred, all of them in non-responders to CRT. Conclusions: Most P with baseline LV and RV systolic dysfunction benefit from CRT, with significant improvement occurring in both LVEF and TAPSE. In P with biventricular dysfunction, response rates to CRT are similar to those reported in the literature for P with isolated LV dysfunction. P885 Incidence and predictors of subclavian vein obstruction following biventricular ICD implantation: a contrast venography study O. Beton O. Beton 1 Cumhuriyet University, Cardiology , Sivas , Turkey E. Saricam E. Saricam 2 Cag Hospital, Cardiology , Ankara , Turkey Z. Kucuksu Z. Kucuksu 3 Mengucek Gazi Training and Research Hospital, Cardiology , Erzincan , Turkey M. Yaman M. Yaman 4 Samsun Education and Research Hospital, Cardiology , Samsun , Turkey A. Zorlu A. Zorlu 1 Cumhuriyet University, Cardiology , Sivas , Turkey H. Kaya H. Kaya 1 Cumhuriyet University, Cardiology , Sivas , Turkey H. Yucel H. Yucel 1 Cumhuriyet University, Cardiology , Sivas , Turkey M.B. Yilmaz M.B. Yilmaz 1 Cumhuriyet University, Cardiology , Sivas , Turkey I. Tandogan I. Tandogan 5 Gozde Academy Hospital, Cardiology , Malatya , Turkey Abstract Aim: The number of biventricular implantable cardioverter defibrillator (Biv-ICD) implantations, as well as follow-up procedures such as generator exchange and lead revision are increased. Venous obstruction becomes a significant challenge in lead revision procedure. The data about the incidence of subclavian venous (SCV) obstruction after Biv-ICD implantation is very limited. The aim of this study was to determine the incidence and predictors of venous obstruction after Biv-ICD implantation. Methods: One hundred and thirteen consecutive patients admitted for their first/second elective Biv-ICD generator replacement and/or lead revision were included. Left SCV puncture method for all three leads implantation was inclusion criteria. All patients underwent left arm contrast venography and the images were analyzed by two attending cardiologists. Venous obstruction was classified as moderate stenosis (50-75% diameter reduction), severe stenosis (>75%) or total occlusion. We assessed clinical risk factors (such as DM, HT, hyperlipidemia, body mass index), co-existing diseases (COPD, peripheral arterial diseases), underlying disease for Biv-ICD implantation, laboratory parameters, models of implanted device and leads, previous history of lead revision, previous history of lead extraction procedure with special extraction devices, clinical symptoms, baseline rhythm, history of antiplatelet/anticoagulant therapy and total lead duration. Results: All leads were placed for an average of 42.7±18.9 months. All patients had dual shocking coil ICD leads. SCV obstruction of various degrees was found in 79% of the patients. Complete occlusion was found in 26%, severe stenosis in 33% and moderate stenosis in 20% of the patients. The incidence of venous obstruction was increased in patients with a previous history of lead revision (71%) and previous history of lead extraction procedure with special extraction devices (100%). Previous history of lead revision and previous history of lead extraction procedure with special extraction devices were significantly related with total occlusion (r=0.64, p<0.001 and r=0.84, p<0.001, respectively). Anticoagulation therapy during and after treatment had statistically strong negative correlation with total occlusion (r= -0.91, p<0.001). Conclusion: This study demonstrated that subclavian vein obstruction occurs relatively frequently after Biv-ICD implantation. Patients with previous history of lead revision and previous history of lead extraction procedure had increased risk for total occlusion. Anticoagulation therapy may help to prevent total occlusion of SCV. P886 Lead to lead mutual connection during extraction with strong connecting tissue scar -interaprocedurally recognised technical problem and its significance A. Kutarski A. Kutarski 1 Medical University of Lublin, Department of Cardiology , Lublin , Poland M. Polewczyk M. Polewczyk 2 District Hospital , Kielce , Poland A.M. Polewczyk A.M. Polewczyk 2 District Hospital , Kielce , Poland A. Polewczyk A. Polewczyk 3 Swietokrzyskie Cardiology Center, II Cardiology Clinic , Kielce , Poland Abstract Strong mutual lead-to-lead connection(L-LC) may impede transvenous lead extraction(TLE). The goal: The analysis of L-LC frequency and its impact on TLE scenario. Materials and methods: We retrospectively analyzed 1767 TLE procedures(2945 extracted leads). Results are presented in the table. Comment: L-LC occurs realtively rarely(4,6% TLE procedures). It is observed in superior vena cava(45%), right atrium(40%), right ventricle(15%). It is frequently accompanied by other technical problems and finally decreases slightly effectiveness of procedure (more major complications and procedure related death, lower percentage of full radiological and procedural success. Operating room stay-in time (whole procedure duration) is longer. Conclusions: L-LC occurs in more complex, difficult procedures and seems to be linked with stronger(after years)tissue adherence forces. This phenomenon should be known to every TLE operator. Results Lead to lead strong scar connection and difficulties of TLE Patient / system / procedure information NO Yes t / X2 P** Number of patients 1677 90 - - Patient’s age (SD) 64,6±16,0 66,12±13,43 0,8846 0,38 Sex (% of male patients) 1020(60,82%) 50(55,56%) 0,9922 0,3 General infection (LDE) 472(28,15%) 21(23,33%) 0,9833 0,3 Local pocket infection 199(11,87%) 13(14,44%) 0,5377 0,47 Non-infective indications 967(57,66%) 56(62,22%) 0,7285 0,39 Number of leads in heart before lead extraction (SD) 1,96±0,79 2,49±0,74 6,2196 0,001 Too long loops or long loop in right atrium or ventricle 100(5,96%) 14(15,56%) 13,023 0,001 Number of procedures before lead extraction 1,85±1,13 2,5±1,38 5,2516 0,001 Mean leads body dwelling time 82,25±62,55 123,81±69,77 6,1032 0,001 Both (R&L) chest side lead extraction 23(1,37%) 8(8,89%) 28,005 0,001 Major complications 23(1,37%) 6(6,67%) 14,836 0,001 Other technical problems during TLE 117(6,98%) 37(41,11%) 125,09 0,001 Full radiological success 1602(95,53%) 80(88,89%) 8,225 0,005 Full Clinical success 1648(98,27%) 84(93,33%) 10,725 0,001 Full procedural success 1601(95,47%) 80(88,89%) 7,9853 0,006 Procedure related death 3(0,18%) 3(3,33%) 25,116 0,001 Operating room stay-in time (whole procedure duration) (minutes) 106,98±44,06 137,1±53,21 6,2462 0,001  Lead to lead strong scar connection and difficulties of TLE Patient / system / procedure information NO Yes t / X2 P** Number of patients 1677 90 - - Patient’s age (SD) 64,6±16,0 66,12±13,43 0,8846 0,38 Sex (% of male patients) 1020(60,82%) 50(55,56%) 0,9922 0,3 General infection (LDE) 472(28,15%) 21(23,33%) 0,9833 0,3 Local pocket infection 199(11,87%) 13(14,44%) 0,5377 0,47 Non-infective indications 967(57,66%) 56(62,22%) 0,7285 0,39 Number of leads in heart before lead extraction (SD) 1,96±0,79 2,49±0,74 6,2196 0,001 Too long loops or long loop in right atrium or ventricle 100(5,96%) 14(15,56%) 13,023 0,001 Number of procedures before lead extraction 1,85±1,13 2,5±1,38 5,2516 0,001 Mean leads body dwelling time 82,25±62,55 123,81±69,77 6,1032 0,001 Both (R&L) chest side lead extraction 23(1,37%) 8(8,89%) 28,005 0,001 Major complications 23(1,37%) 6(6,67%) 14,836 0,001 Other technical problems during TLE 117(6,98%) 37(41,11%) 125,09 0,001 Full radiological success 1602(95,53%) 80(88,89%) 8,225 0,005 Full Clinical success 1648(98,27%) 84(93,33%) 10,725 0,001 Full procedural success 1601(95,47%) 80(88,89%) 7,9853 0,006 Procedure related death 3(0,18%) 3(3,33%) 25,116 0,001 Operating room stay-in time (whole procedure duration) (minutes) 106,98±44,06 137,1±53,21 6,2462 0,001  Results Lead to lead strong scar connection and difficulties of TLE Patient / system / procedure information NO Yes t / X2 P** Number of patients 1677 90 - - Patient’s age (SD) 64,6±16,0 66,12±13,43 0,8846 0,38 Sex (% of male patients) 1020(60,82%) 50(55,56%) 0,9922 0,3 General infection (LDE) 472(28,15%) 21(23,33%) 0,9833 0,3 Local pocket infection 199(11,87%) 13(14,44%) 0,5377 0,47 Non-infective indications 967(57,66%) 56(62,22%) 0,7285 0,39 Number of leads in heart before lead extraction (SD) 1,96±0,79 2,49±0,74 6,2196 0,001 Too long loops or long loop in right atrium or ventricle 100(5,96%) 14(15,56%) 13,023 0,001 Number of procedures before lead extraction 1,85±1,13 2,5±1,38 5,2516 0,001 Mean leads body dwelling time 82,25±62,55 123,81±69,77 6,1032 0,001 Both (R&L) chest side lead extraction 23(1,37%) 8(8,89%) 28,005 0,001 Major complications 23(1,37%) 6(6,67%) 14,836 0,001 Other technical problems during TLE 117(6,98%) 37(41,11%) 125,09 0,001 Full radiological success 1602(95,53%) 80(88,89%) 8,225 0,005 Full Clinical success 1648(98,27%) 84(93,33%) 10,725 0,001 Full procedural success 1601(95,47%) 80(88,89%) 7,9853 0,006 Procedure related death 3(0,18%) 3(3,33%) 25,116 0,001 Operating room stay-in time (whole procedure duration) (minutes) 106,98±44,06 137,1±53,21 6,2462 0,001  Lead to lead strong scar connection and difficulties of TLE Patient / system / procedure information NO Yes t / X2 P** Number of patients 1677 90 - - Patient’s age (SD) 64,6±16,0 66,12±13,43 0,8846 0,38 Sex (% of male patients) 1020(60,82%) 50(55,56%) 0,9922 0,3 General infection (LDE) 472(28,15%) 21(23,33%) 0,9833 0,3 Local pocket infection 199(11,87%) 13(14,44%) 0,5377 0,47 Non-infective indications 967(57,66%) 56(62,22%) 0,7285 0,39 Number of leads in heart before lead extraction (SD) 1,96±0,79 2,49±0,74 6,2196 0,001 Too long loops or long loop in right atrium or ventricle 100(5,96%) 14(15,56%) 13,023 0,001 Number of procedures before lead extraction 1,85±1,13 2,5±1,38 5,2516 0,001 Mean leads body dwelling time 82,25±62,55 123,81±69,77 6,1032 0,001 Both (R&L) chest side lead extraction 23(1,37%) 8(8,89%) 28,005 0,001 Major complications 23(1,37%) 6(6,67%) 14,836 0,001 Other technical problems during TLE 117(6,98%) 37(41,11%) 125,09 0,001 Full radiological success 1602(95,53%) 80(88,89%) 8,225 0,005 Full Clinical success 1648(98,27%) 84(93,33%) 10,725 0,001 Full procedural success 1601(95,47%) 80(88,89%) 7,9853 0,006 Procedure related death 3(0,18%) 3(3,33%) 25,116 0,001 Operating room stay-in time (whole procedure duration) (minutes) 106,98±44,06 137,1±53,21 6,2462 0,001  P887 Complete extraction of abdominal pacing and ICD leads- A unique case series G. Ganesha Babu G. Ganesha Babu V. Cobb V. Cobb S. Ahsan S. Ahsan R. Providencia R. Providencia V. Posdziech V. Posdziech A. Chow A. Chow University College Hospital, Electrophysiology , London , United Kingdom Abstract Introduction: Abdominal pacing/ICDs generators are now rarely implanted, owing to the smaller sized pectoral units. They were typically inserted by the surgeons under the rectus muscle and the leads are tunnelled from the abdominal site to left infraclavicular area and the leads are then inserted transvenously through a subclavian or axillary vein approach. It is extremely rare that these systems need to be extracted and there are no published data on the techniques or outcomes. The procedure poses different risks and technique difficulties compared to standard lead extraction procedures. Methods: Retrospective case record analyses of extractions were undertaken over last 10 year period in single high volume centre. Results: A total of 280 lead extraction cases have been performed over the last 10 years. A total of 5 of these cases were extraction for abdominal ICDs comprising only 1.8 % of extractions. All procedures were performed under general anaesthesia. The mean age was 51.4 yrs, 4/5 ( 80%) were female. Indications and demographics are shown in the table. Two separate incisions were needed to access the generator, connectors and to remove the endovascular portions of the leads. The abdominal portion of the leads were dissected free and pulled through to the shoulder. Laser extraction was then used to remove the intravascular portions of the leads. All 5 patients had successful complete removal of the leads and generators and re-implantation of new pectoral devices with no complications. Conclusions: Abdominal pacing/ICD lead extractions are rare and pose unique technical challenges but can be safely and successfully removed by a combination of simple traction, dissection and laser extraction tools. Demographic N Percentage General Anesthesia 5 100% Female 4 80% ICD 4 80% Pacemaker 1 20% Lead system failure 4 80% RV Perforation 1 20% Paediatric implant 1 20% Free Floating SVC coil present 4 80%  Demographic N Percentage General Anesthesia 5 100% Female 4 80% ICD 4 80% Pacemaker 1 20% Lead system failure 4 80% RV Perforation 1 20% Paediatric implant 1 20% Free Floating SVC coil present 4 80%  Demographic N Percentage General Anesthesia 5 100% Female 4 80% ICD 4 80% Pacemaker 1 20% Lead system failure 4 80% RV Perforation 1 20% Paediatric implant 1 20% Free Floating SVC coil present 4 80%  Demographic N Percentage General Anesthesia 5 100% Female 4 80% ICD 4 80% Pacemaker 1 20% Lead system failure 4 80% RV Perforation 1 20% Paediatric implant 1 20% Free Floating SVC coil present 4 80%  P888 Transvenous extraction of very old (over 20-year-old) leads using mechanical systems - effectiveness and safety A. Zabek A. Zabek 1 Department of Electrocardiology, John Paul II Hospital in Krakow , Krakow , Poland K. Boczar K. Boczar 1 Department of Electrocardiology, John Paul II Hospital in Krakow , Krakow , Poland K. Haberka K. Haberka 1 Department of Electrocardiology, John Paul II Hospital in Krakow , Krakow , Poland M. Debski M. Debski 1 Department of Electrocardiology, John Paul II Hospital in Krakow , Krakow , Poland R. Pfitzner R. Pfitzner 2 Jagiellonian University, John Paul II Hospital, Dept of Cardiovascular Surgery & Transplantology , Krakow , Poland J. Lelakowski J. Lelakowski 3 Jagiellonian University Medical College, John Paul II Hospital in Krakow, Department of Electrocardiology , Krakow , Poland B. Malecka B. Malecka 3 Jagiellonian University Medical College, John Paul II Hospital in Krakow, Department of Electrocardiology , Krakow , Poland Abstract Purpose: To analyse the effectiveness and safety of transvenous lead extraction (TLE) of leads older than 20 years using mechanical systems. Methods: The study included 242 pts, mean age 67.2±12.3 years, 85 female, qualified to TLE. Patients were divided in two groups: A – 13 pts, 14 leads extracted with dwell time ≥ 240 months (also 10 lead extracted with dwell-time <240 monts); B - 229 pts, 332 leads extracted. Results: Pts in both groups did not differ in terms of age, gender, NYHA functional class, left ventricle ejection fraction (LVEF) and indications to TLE. In group A patients had more device-related procedures performed in the past and more unipolar leads compared to group B. In all patients from group A the complete success was achieved and neither major or minor complications were observed. In group A femoral access and Evolution sheaths were utilized more frequently and the procedure time was longer. Conclusions: This study shows that extraction of leads older than 20 years seems to be comparably safe and effective to extraction of younger leads. On the other hand, it requires longer fluoroscopy time and frequent utilization of advanced tools. Results Parameter Group A Group B P value Age of patients (years±SD) 66.7±8.3 67.2±12.5 P=0.5439 Female gender [n, %] 7 (53.8%) 78 (34.1%) P=0.2481 Number of extracted leads 24 332 - Age of extracted leads (months±SD) 214.9±105.0 70.9±45.8 P<0.0001 Complete success [n, %] 13 (100.0%) 220 (96.1%) P=0.7669 Clinical success [n, %] 0 (0.0%) 5 (2.2%) Failure [n, %] 0 (0.0%) 4 (1.7%) No complication [n, %] 13 (100.0%) 217 (94.7%) P=0.6988 Minor complication [n, %] 0 (0.0%) 7 (3.1%) Major complication [n, %] 0 (0.0%) 5 (2.2%) Simple traction [n, %] 3 (12.5%) 85 (25.6%) P=0.0013 Telescopic sheats [n, %] 17 (70.8%) 239 (72.0%) Evolution mechanical system [n, %] 3 (12.5%) 5 (1.5%) Femoral access [n, %] 1 (4.2%) 3 (0.9%) Total flouroscopy time (min±SD) 45.9±14.0 5.8±9.6 P<0.0001  Parameter Group A Group B P value Age of patients (years±SD) 66.7±8.3 67.2±12.5 P=0.5439 Female gender [n, %] 7 (53.8%) 78 (34.1%) P=0.2481 Number of extracted leads 24 332 - Age of extracted leads (months±SD) 214.9±105.0 70.9±45.8 P<0.0001 Complete success [n, %] 13 (100.0%) 220 (96.1%) P=0.7669 Clinical success [n, %] 0 (0.0%) 5 (2.2%) Failure [n, %] 0 (0.0%) 4 (1.7%) No complication [n, %] 13 (100.0%) 217 (94.7%) P=0.6988 Minor complication [n, %] 0 (0.0%) 7 (3.1%) Major complication [n, %] 0 (0.0%) 5 (2.2%) Simple traction [n, %] 3 (12.5%) 85 (25.6%) P=0.0013 Telescopic sheats [n, %] 17 (70.8%) 239 (72.0%) Evolution mechanical system [n, %] 3 (12.5%) 5 (1.5%) Femoral access [n, %] 1 (4.2%) 3 (0.9%) Total flouroscopy time (min±SD) 45.9±14.0 5.8±9.6 P<0.0001  Results Parameter Group A Group B P value Age of patients (years±SD) 66.7±8.3 67.2±12.5 P=0.5439 Female gender [n, %] 7 (53.8%) 78 (34.1%) P=0.2481 Number of extracted leads 24 332 - Age of extracted leads (months±SD) 214.9±105.0 70.9±45.8 P<0.0001 Complete success [n, %] 13 (100.0%) 220 (96.1%) P=0.7669 Clinical success [n, %] 0 (0.0%) 5 (2.2%) Failure [n, %] 0 (0.0%) 4 (1.7%) No complication [n, %] 13 (100.0%) 217 (94.7%) P=0.6988 Minor complication [n, %] 0 (0.0%) 7 (3.1%) Major complication [n, %] 0 (0.0%) 5 (2.2%) Simple traction [n, %] 3 (12.5%) 85 (25.6%) P=0.0013 Telescopic sheats [n, %] 17 (70.8%) 239 (72.0%) Evolution mechanical system [n, %] 3 (12.5%) 5 (1.5%) Femoral access [n, %] 1 (4.2%) 3 (0.9%) Total flouroscopy time (min±SD) 45.9±14.0 5.8±9.6 P<0.0001  Parameter Group A Group B P value Age of patients (years±SD) 66.7±8.3 67.2±12.5 P=0.5439 Female gender [n, %] 7 (53.8%) 78 (34.1%) P=0.2481 Number of extracted leads 24 332 - Age of extracted leads (months±SD) 214.9±105.0 70.9±45.8 P<0.0001 Complete success [n, %] 13 (100.0%) 220 (96.1%) P=0.7669 Clinical success [n, %] 0 (0.0%) 5 (2.2%) Failure [n, %] 0 (0.0%) 4 (1.7%) No complication [n, %] 13 (100.0%) 217 (94.7%) P=0.6988 Minor complication [n, %] 0 (0.0%) 7 (3.1%) Major complication [n, %] 0 (0.0%) 5 (2.2%) Simple traction [n, %] 3 (12.5%) 85 (25.6%) P=0.0013 Telescopic sheats [n, %] 17 (70.8%) 239 (72.0%) Evolution mechanical system [n, %] 3 (12.5%) 5 (1.5%) Femoral access [n, %] 1 (4.2%) 3 (0.9%) Total flouroscopy time (min±SD) 45.9±14.0 5.8±9.6 P<0.0001  P889 Early repolarization in unexplained syncope S. Loebe S. Loebe J. Kornej J. Kornej A. Arya A. Arya H. Hindricks H. Hindricks A. Bollmann A. Bollmann D. Husser D. Husser University of Leipzig, Heart Center, Department of Electrophysiology , Leipzig , Germany Abstract Background: Early repolarization (ER) is characterized by J-point elevation in the anterolateral or inferior leads of the 12-lead electrocardiogram. It has been associated with increased risk for idiopathic ventricular fibrillation and mortality. However, its prevalence in syncope of different etiologies is unknown and was evaluated in this study. Methods: The study sample comprised 170 consecutive patients with vasovagal syncope (positive tilt table response and a representative history, group 1, n=59) or syncope that remained unexplained after complete work-up (group 2, n=111). ER was defined as an elevation of the QRS-ST junction of at least 0.1 mV from baseline in at least two adjacent inferior (II, III, aVF) or anterolateral (I, aVL, V4 – V6) leads. Results: Age, gender, heart rate, PQ interval and QRS duration were similar between groups but QTc interval was shorter in group 2 compared with group 1 (378±26 vs. 395±25 ms, p<.001). ER was more frequently observed in group 2 than in group 1 (22.5 vs. 6.8 %, p=.032). ER in inferior leads was more prevalent in group 2 (17.1 vs 3.4 %, p=.01) while ER in anterolateral leads was similar between group. The type of ER was identical in both groups, i.e. slurring was observed in 80 % and notching in 20 %. The ST-Segment after ER was horizontal/ descending in 0% in group 1 matched with 13.5% (p=0.002) in group 2. Conclusion: Early repolarization in inferior leads and with an horizontal/ descending ST-Segment is more frequently found in subjects with unexplained syncope than in subjects with vasovagal syncope. This finding may be linked with worse prognosis of unexplained syncope but further studies are warranted to assess its prognostic and therapeutic implications. P890 The role of QT intervals in prognosis of syncope of unknown origin A. Fotoglidis A. Fotoglidis C. Papadopoulos C. Papadopoulos N. Fragakis N. Fragakis E. Pagourelias E. Pagourelias D. Tanos D. Tanos V. Skeberis V. Skeberis P. Kyriakou P. Kyriakou V. Vassilikos V. Vassilikos Aristotle University of Thessaloniki, 3rd Cardiology Department , Thessaloniki , Greece Abstract Background: Its known that prolonged Tpeak-to-Tend interval(TpTe) is associated with increased risk of mortality in patients with cardiac diseases such as coronary artery disease(CAD), long QT syndromes and hypertrophic cardiomyopathy and that increased QT dispersion(QTdisp) is a major risk factor for torsades de pointes tachycardia. The aim of the study was to evaluate the role of QT intervals in prediction of new syncopal spells during one year after initial assessment of patients with syncope of unknown origin(SUO). Method: During a two year period 85 patients with SUO evaluated. Demographic characteristics recorded and specific diagnostic protocol used. QT minimum, QT maximum, QTpeak(in lead with QTmax), QT dispersion,QT corrected(in lead with QTmax),TpTe(in lead with QTmax) and TpTe dispersion(TpTedisp) measured. Patients were followed for a mean period of one year. Results: 85 patients with mean age 56±20, 32 women(38,8%) and 53 men(61,2%) enrolled. 67 out of 85(78,8%) had not structural heart disease. QT intervals measured and mean values calculated : mean QTmax 411±47ms, mean QTmin 362±40 ms, mean QTpeak 324± 43 ms, mean QTdisp 49±17ms, mean QTc 428±35ms, mean TpTe 87±18 ms and mean TpTedisp 36±11ms. It was detected that TpTe was sex related, more prolonged in men (91 vs 82 p 0,027) and QTpeak was age related, more prolonged in age above 65 years(339 vs 314 p 0,01). Moreover,patients with CAD had prolonged QTmax(447 vs 402 p 0,009), QT min(393 vs 354 p 0,009), QTpeak(355 vs 316 p 0,008) and QTc(455 vs 421 p 0,007). During one year mean follow up 14 patients(16,5%) had at least one syncopal episode. In order to evaluate the predictive role of QT intervals in recurrence of syncopal spells cut-off values calculated : QTmax >390ms [sensibility(sens) 71%-specificity(spec) 69%], QT min > 350ms(sens 71%-spec 62%), QT peak >315 ms(sens 79%-spec 56%), QTdisp >36,5ms(sens 86%-spec 89%), QTc >416,5ms(sens 71,4%-spec 56%), TpTe >75ms(sens 71% -spec 85%), TpTedisp >25ms(sens 64% - spec 85%), with an area under ROC curve of 57%, 58%, 63%, 45%, 56%, 40%, 39% respectively. It was also detected that CAD or age above 65 year had significant negative predictive value (86,6% and 87% respectively) in relapse of syncopal episodes. Conclusions: In our study QT intervals could poorly predict the reappearance of syncopal spells. However,it was detected that patients with CAD or age older than 65 are more susceptible to QT intervals variabilities and that the absence of such risk factors reduces the recurrence rate of syncope. Consequently,those patients need thorough diagnostic assessment and frequent reappraisal. P891 Right ventricular diastolic dysfunction in children with WPW syndrome: invasive hemodynamic study I.A. Khamnagadaev I.A. Khamnagadaev 1 Research Clinical Institute of pediatrics, arrhythmology department , Moscow , Russian Federation S.A. Termosesov S.A. Termosesov 1 Research Clinical Institute of pediatrics, arrhythmology department , Moscow , Russian Federation M.A. Shkolnikova M.A. Shkolnikova 1 Research Clinical Institute of pediatrics, arrhythmology department , Moscow , Russian Federation L.S. Kokov L.S. Kokov 2 The Sklifosovsky Research Institute for Emergency Medicine , Moscow , Russian Federation Y. Volkova Y. Volkova 1 Research Clinical Institute of pediatrics, arrhythmology department , Moscow , Russian Federation R.S. Garipov R.S. Garipov 1 Research Clinical Institute of pediatrics, arrhythmology department , Moscow , Russian Federation I.L. Ilich I.L. Ilich 1 Research Clinical Institute of pediatrics, arrhythmology department , Moscow , Russian Federation Abstract Purpose: To evaluate the impact of ventricular pre-excitation on right ventricular (RV) diastolic function in children with Wolff-Parkinson-Wight syndrome (WPW). Methods: In 2003-2014, 1350 children aged 1 to 17 yo with WPW received catheter ablation (RCA) of accessories pathways (AP) in one catheterization laboratory. 70 of them (35 females) were included into the study. Main group – 47 pts with WPW (21 asymptomatic WPW). Control group – 23 pts with atrioventricular nodal re-entrant tachycardia. ECG, 24-hour Holter monitoring and echocardiography were performed before and 3 days after interventional procedure. Invasive right ventricular pressure was recorded immediately before and 40 minutes after RCA. First negative derivate (max) and time constant (T) of RV pressure fall were calculated. Those data have been included into logistic regression model. Regression coefficients, odds ratio and probability of RV diastolic function disturbance depending on localization of AP were calculated. Results: RV diastolic function was impaired in 23 (49%) pts in main group before interventional treatment. There were no RV diastolic dysfunctions after RCA in all cases. Disturbance of RV diastolic function was not found in control group before and after RCA in all pts. The probability (P) of RV diastolic function disturbance has been calculated using regression model. In pts with right-side AP P was 0.9, in pasaseptal – 0.7, in left-side – 0.1 (p<0.05). There was no significant difference in RV diastolic function in symptomatic and asymptomatic WPW. Conclusion: Abnormal ventricular excitation via AP causes RV diastolic dysfunction in WPW. Probability of RV diastolic function disturbance in right-side AP higher than in pasaseptal AP. Left-side AP associated with low risk of RV diastolic dysfunction. Ventricular pre-excitation via AP causes the same RV diastolic function in symptomatic and asymptomatic WPW. P892 Acute right ventricular apex pacing with an altered activation pattern reduces electrical parameters but does not modify torsade de pointes incidence in the anesthetized chronic complete AV-block dog M.A. Vos M.A. Vos University Medical Center Utrecht, Department of Medical Physiology , Utrecht , Netherlands H.D.M. Beekman H.D.M. Beekman T.R.G. Stams T.R.G. Stams V.J.A. Bourgonje V.J.A. Bourgonje A. Oros A. Oros S.C. Wijers S.C. Wijers A. Bossu A. Bossu R. Varkevisser R. Varkevisser A. Dunnink A. Dunnink Abstract Purpose: Complete AV-block leads to bradycardia and an uncontrolled altered ventricular activation pattern of the idioventricular rhythm: IVR, which is most often originating in the left ventricle (LV). The ensuing ventricular remodelling reduces repolarization reserve, is region specific (early vs. late activated areas), and enhances susceptibility for dofetilide induced Torsade de Pointes (TdP) arrhythmias, which often occur in the later activated regions. Administration of anaesthesia and dofetilide further increase the cycle length (CL) and sometimes shift the focus of the IVR. To control the latter effects, we paced the hearts acutely from the right ventricular apex (RVA) at 1000 ms CL and investigated the electrophysiological and arrhythmic consequences. Methods: 54 anaesthetised (pentobarbital+isoflurane) dogs with remodeled hearts (> 3 weeks AV-block) were challenged with dofetilide (0.025 mg/kg/5min): 32 animals in IVR and 22 RVA paced. ECG, endocardial LV and RV monophasic action potential durations (MAPd) were recorded. Results: CL of the IVR dogs was 1283±282 ms and the rhythm originated from the LV in 27/32 animals. LVMAPd, spatial (ΔMAPd = LV - RVMAPd) and temporal dispersion of repolarization (STV_LV) were larger in IVR (table 1). Despite these baseline differences TdP inducibility remained similar, 59% (19/32) vs. 64% (14/22). Dofetilide increased CL of the IVR dogs to 1432±320 ms while the relative increase of LVMAPd and STV_LV were similar in both groups although absolute values remained larger in IVR (table 1). In contrast, the relative increase in ΔMAPd was nearly twice as high in the RVA paced dogs and thereby reaching similar absolute values as IVR (table 1). TdP remained originating from the late(r) activated region in IVR. Conclusion: Acute RVA pacing does not affect TdP outcome or origin. The lower absolute repolarization values in RVA paced dogs are most likely due to the higher heart rate. However, ΔMAPd is the only electrical parameter increasing to the same magnitude suggesting the importance of spatial dispersion of repolarization for development of TdP. Table 1: Electrophysiological data  IVR_BL IVR_DOF % Increase RVA paced_BL RVA paced_DOF % Increase LVMAPd 303±51 475±114º 57 257±29* 404±80º* 57 STV_LV 1.3±0.6 3.5±1.3º 167 0.9±0.4* 2.2±1.7º* 139 ΔMAPd 40±27 93±64º 134 21±23* 70±54º 237   IVR_BL IVR_DOF % Increase RVA paced_BL RVA paced_DOF % Increase LVMAPd 303±51 475±114º 57 257±29* 404±80º* 57 STV_LV 1.3±0.6 3.5±1.3º 167 0.9±0.4* 2.2±1.7º* 139 ΔMAPd 40±27 93±64º 134 21±23* 70±54º 237  BL, baseline; DOF, dofetilide; ° p<0.05 (DOF vs BL); * p<0.05 (RVA vs IVR) Table 1: Electrophysiological data  IVR_BL IVR_DOF % Increase RVA paced_BL RVA paced_DOF % Increase LVMAPd 303±51 475±114º 57 257±29* 404±80º* 57 STV_LV 1.3±0.6 3.5±1.3º 167 0.9±0.4* 2.2±1.7º* 139 ΔMAPd 40±27 93±64º 134 21±23* 70±54º 237   IVR_BL IVR_DOF % Increase RVA paced_BL RVA paced_DOF % Increase LVMAPd 303±51 475±114º 57 257±29* 404±80º* 57 STV_LV 1.3±0.6 3.5±1.3º 167 0.9±0.4* 2.2±1.7º* 139 ΔMAPd 40±27 93±64º 134 21±23* 70±54º 237  BL, baseline; DOF, dofetilide; ° p<0.05 (DOF vs BL); * p<0.05 (RVA vs IVR) P893 Expression of miRNAs and morphological changes in myocardium of patients with atrial fibrillation A.S.H. Revishvili A.S.H. Revishvili Bakoulev Center for Cardiovascular Surgery RAMS , Moscow , Russian Federation V.A. Vaskovskiy V.A. Vaskovskiy V.S. Rudomanova V.S. Rudomanova A.G. Ibragimova A.G. Ibragimova T.V. Sukhacheva T.V. Sukhacheva M.V. Eremeeva M.V. Eremeeva Abstract Introduction: It is discussed that miRNAs are potent mediators of atrial remodeling. AF is accompanied by the development of fibrosis, lipomatosis, hypertrophy of myocardium and atrial dilatation.We decided to find out how these processes are associated with the expression of miRNAs. Methods: The level of 9 miRNA (mir1, 133a/b, 208a/b, 499, 195, 29, 21) expression was studied in left atrial appendage (LAA) myocardium of patients (age 55,1±9,4 years) with paroxysmal (PAF, n=11), persistent (PsAF, n=20), long-standing atrial fibrillation (LSAF, n=23) and patients in the control group with sinus rhythm (SR, n=12) (age 50,3±13,6 years). We used the intraoperative myocardial LAA biopsy obtained during RF maze procedure or aortic valve replacement in patients with SR without AF. The degree of interstitial fibrosis(%), lipomatosis, isolated atrial amyloidosis (IAA) we determined semiquantitatively and cardiomyocyte hypertrophy were assessed by morphometry methods.The level of expression of miRNA was evaluated by RT-PCR. Statistical analysis was made using non-parametric Mann-Whitney U test and Spearman correlation (p<0,05). Results: The screening of 9 miRNAs revealed increased expression in PAF patients (mir208a), in PsAF patients (mir1, 208a) and LSAF patients (mir208a, 208b) compared with the SR group (p<0,05), and miRNAs upregulation in LSAF patients (mir1, 133b, 499, 29a) compared with PsAF patients (p<0,05). Correlation analysis showed miRNAs involvement in atrial structural remodeling in patients with different forms of AF.In PAF patients miRNAs upregulation correlated with increased interstitial fibrosis (mir133b), lipomatosis (mir208a, 133b), IAA (mir208a/b, 133a, 499, 195, 1, 29a, 21) and cardiomyocyte hypertrophy (mir208b) (p<0,05). In PsAF patients miRNAs expression correlated with interstitial fibrosis (mir208a, 133a) and dilatation of the mitral (mir208b) and tricuspid (mir133a) valve rings (p<0,05). In LSAF patients expression of mir208b was associated with an increase of the left atrial size and a number of miRNAs were involved in the regulation of interstitial fibrosis (mir208a, 195, 499, 29a), mitral valve ring dilatation (mir499) and inversely correlated with IAA (mir499, 21)(p<0,05). Conclusions: A number of miRNAs(mir208a/b, 133a, 499, 21) were involved in the regulation of atrial structural remodeling (fibrosis, lipomatosis, IAA, cardiomyocyte hypertrophy) in patients with AF. P894 Spectrum of long qt gene mutations in the republic of ireland A. Green A. Green 4 Our Lady's Children's Hospital, Crumlin, National Centre for Medical Genetics , Dublin , Ireland S.A. Lynch S.A. Lynch 4 Our Lady's Children's Hospital, Crumlin, National Centre for Medical Genetics , Dublin , Ireland C. Mcgorrian C. Mcgorrian 1 Mater Misericordiae University Hospital , Cardiology , Dublin , Ireland D. Ward D. Ward 3 Adelaide & Meath Hospital , Dublin , Ireland J.O. O'neill J.O. O'neill 2 Connolly/Mater Hospitals/RCSI , Dublin , Ireland B. Noonan B. Noonan 1 Mater Misericordiae University Hospital , Cardiology , Dublin , Ireland S. Touhy S. Touhy 1 Mater Misericordiae University Hospital , Cardiology , Dublin , Ireland D.P. Moran D.P. Moran 1 Mater Misericordiae University Hospital , Cardiology , Dublin , Ireland W. Reardon W. Reardon 4 Our Lady's Children's Hospital, Crumlin, National Centre for Medical Genetics , Dublin , Ireland J. Galvin J. Galvin 1 Mater Misericordiae University Hospital , Cardiology , Dublin , Ireland Abstract Aims: Using the iGene database of genetic mutations in the National Centre for Medical Genetics (NCMG), we sought to describe the prevalence of positively identified LQTS gene mutations in those patient sent for analysis of KCNQ1, KCNH2, SCN5A, KCNE1 and KCNE2 genes. We also sought to describe the relative incidence of each positively identified gene mutation to gain an insight into the prevalence of the different LQTS mutations within the Irish population. Methods: A retrospective review of all patient and family files referred for LQTS gene analysis in the National Centre for Medical Genetics was performed, and the relevant genetic information was entered into a database. The specific gene mutations analyzed for each patient were recorded, as well as the amino acid change coded for by that mutation, as well as the region that the mutation correlated to. Data collection was performed over a 14 month period from July 2012 to the end of September 2013. Results: Of the 424 samples analyzed, 180 (42.45%) tested positive for an LQTS gene mutation. 64 patients tested positive for a KCNQ1 gene mutation (35.6%), 63 patients tested positive for a KCNH2 gene mutation (35%), 36 patients tested positive for an SCN5A gene mutation (20%), 17 patients tested positive for a KCNE1 gene mutation (9.4%) and 4 patients tested positive for a KCNE2 gene mutation (2.2%). Conclusions: These results suggest an over-representation of SCN5A and KCNE2 mutations when compared to the previously described spectrum of LQTS gene mutations in the five most common LQTS genes in a European and North American cohort. Pie chart of genotypes identified P895 Cardiomyopathies associated with mutations in SCN5A gene E. Zaklyazminskaya E. Zaklyazminskaya 1 B.V. Petrovsky Russian Scientific Center of Surgery of the Russian Academy of Medical Sciences , Moscow , Russian Federation A. Revishvili A. Revishvili 2 Bakoulev Center for Cardiovascular Surgery RAMS , Moscow , Russian Federation I. Pronicheva I. Pronicheva 2 Bakoulev Center for Cardiovascular Surgery RAMS , Moscow , Russian Federation A. Shestak A. Shestak 1 B.V. Petrovsky Russian Scientific Center of Surgery of the Russian Academy of Medical Sciences , Moscow , Russian Federation S. Dzemeshkevich S. Dzemeshkevich 1 B.V. Petrovsky Russian Scientific Center of Surgery of the Russian Academy of Medical Sciences , Moscow , Russian Federation Abstract The SCN5A gene encodes the alpha subunit of the Nav1.5 sodium channel, which is responsible for the inward sodium current (INa). Genetic alterations in the SCN5A gene may affect the structure, function or level of expression of the Nav1.5 sodium channel. These diverse and often functionally opposite alterations of cardiomyocyte electrical excitability result in various cardiac arrhythmias, and all of them are often associated with a structurally normal heart. It was recently demonstrated that the phenotypic expression of SCN5A genetic mutations could be expanded from electrical disorders with an apparently normal heart to cardiomyopathies. Currently, more than 10 mutations in the SCN5A gene have been described which lead to the development of DCM and/or atrial cardiomyopthy in conjunction with a wide range of cardiac arrhythmias and conduction disorders. We did perform DNA diagnostics for primary arrhythmias since 1998 year, and 232 unrelated families underwent molecular genetic testing, including direct Sanger sequencing of SCN5A gene. Twenty-one mutations in 22 unrelated families in SCN5A gene were found, one proband have carried two mutations in two SCN5A alleles inherited from both parents. Detailed clinical and instrumental examinations including ECG, EchoCG, cardiac MRI, and neurological examination were performed for SCN5A mutation carriers (probands) regardless of underlying diagnosis of primary arrhythmia. The screening had revealed 4 patients (18%) with undoubted structural cardiac remodeling (Table 1). Conclusion: It seems that the prevalence of different variants of cardiac remodeling in SCN5A-mutations carriers is higher than previously thought. A detailed understanding of all the phases (molecular, cellular, organ) of myocardial remodeling in patients with SCN5A mutations is required to select the most effective strategies for personalized therapy based on existing treatments. Cardiopathies in SCN5A-mutation carriers Mutation Age, y.o. Gender Primary diagnosis Cardiomyopathy p.I388F 32 F PVC ARVC p.E446K 54 M CCD Dilated cardiomyopathy p.S1431R+ p.A572D 16 F SSS Cardiac hypertrophy p.P2005A 20 F LQTS, VF, SCD Cardiac hypertrophy  Mutation Age, y.o. Gender Primary diagnosis Cardiomyopathy p.I388F 32 F PVC ARVC p.E446K 54 M CCD Dilated cardiomyopathy p.S1431R+ p.A572D 16 F SSS Cardiac hypertrophy p.P2005A 20 F LQTS, VF, SCD Cardiac hypertrophy  Cardiopathies in SCN5A-mutation carriers Mutation Age, y.o. Gender Primary diagnosis Cardiomyopathy p.I388F 32 F PVC ARVC p.E446K 54 M CCD Dilated cardiomyopathy p.S1431R+ p.A572D 16 F SSS Cardiac hypertrophy p.P2005A 20 F LQTS, VF, SCD Cardiac hypertrophy  Mutation Age, y.o. Gender Primary diagnosis Cardiomyopathy p.I388F 32 F PVC ARVC p.E446K 54 M CCD Dilated cardiomyopathy p.S1431R+ p.A572D 16 F SSS Cardiac hypertrophy p.P2005A 20 F LQTS, VF, SCD Cardiac hypertrophy  P896 Xanthine oxidase inhibitor prevents atrial fibrillation susceptibility by inhibition of oxidative CaMKII in Dahl salt-sensitive rats D.Z. Xu D.Z. Xu N. Murakoshi N. Murakoshi T. Kimura T. Kimura K. Tajiri K. Tajiri A. Nogami A. Nogami K. Aonuma K. Aonuma Cardiovascular division, Institute of Clinical Medicine, Graduate School of Comprehensive Human Scie , Tsukuba , Japan Abstract Background: Beneficial effects of xanthine oxidase inhibition on heart failure have been reported in both experimental and clinical studies. However, the effects of the reagents for atrial fibrillation (AF) remain to be fully elucidated. We investigated the effects of a novel xanthine oxidase inhibitor febuxostat on AF compared to allopurinol in rat model. Methods: Four-week-old Dahl salt-sensitive rats were fed to either 0.3% (low-salt) NaCl or 8% (high-salt) NaCl diet. High-salt diet rats were divided into 3 groups: orally administered to vehicle (8%-control), febuxostat (5mg/kg/day) (8%-febuxostat), or allopurinol (50mg/kg/day) (8%-allopurinol). After 8-weeks of diet, cardiac function was analyzed by echocardiography, and AF induction study was performed through transvenous catheter. The gene and protein expression and histologic findings were compared between 4 groups. Results: AF duration was significantly prolonged in 8%-control compared with 0.3%-control, and significantly suppressed in both 8%-febsostat and 8%-allopurinol (0.3%C; 5.8±3.5 sec, 8%C; 33.9±23.7 sec, 8%F; 15.0±14.1 sec, 8%A; 20.1±11.9 sec: P<0.05). Atrial expressions of calcium-handling-related genes and protein, CaMKII (oxidative CaMKII), RyR2 (Ser2814-RyR2) and SERCA-2a (phosphor-SERCA2a), were significantly elevated in 8%-control, and were significantly reduced in 8%-Febuxostat. The immunohistochemistry study shows abnormal distribution of connexin 40 in 8%-control rats, but it was improved by treatment with both febuxostat and allopurinol. Conclusion: Febuxostat can reduce hypertension-related increase in AF vulnerability by alternation of Ca2+ handling pathway. P897 Results of clinical testing of a cloud computing based ambulatory ecg monitoring and arrhythmia detection system I. Crozier I. Crozier D. Hooks D. Hooks M. Daly M. Daly I. Melton I. Melton C. Cruickshank C. Cruickshank K. Morgan K. Morgan L. Minarsch L. Minarsch Christchurch Hospital, Electrophysiology and Cardiology , Christchurch , New Zealand Abstract Introduction: Current ambulatory arrhythmia detection systems suffer from high overhead costs related to both maintenance of local computational resource and technician input. Cloud computing offers off-site, scalable, data storage and analysis, at low cost. In this study, we conducted a first-in-human trial of a novel cloud-based arrhythmia detection system (MoMe™, Infobionic, Lowell, MA), capable of transmitting surface ECG data to cloud servers for extended periods of ambulatory monitoring. This system has a web and iPad interface to both enroll and review monitoring data. Methods: Forty consecutive patients (21 males, 19 females, and ages 18 - 80) with diagnosed primary arrhythmias including atrial fibrillation (11), supraventricular tachycardia (8), paroxysmal atrial fibrillation (5), ventricular ectopy (3), sinus node dysfunction (2), and inappropriate sinus tachycardia (2) were enrolled. Patients were fitted with the device, consisting of 4 body-surface electrodes connected to a recording unit capable of continuous ECG capture and symptom annotation via a press-button feature. Data was transmitted from the device via Bluetooth® to a Smart Phone and subsequently uploaded to the cloud on the 3G commercial cellular network. Custom software analyzed transmitted data in the cloud for occurrence of arrhythmia. Results: Patients were successfully monitored for 14-30 day periods, with no significant adverse events. Event notification function was confirmed in all patients. Heart rhythm was successfully captured by the device and extracted by automated rhythm analysis in 39/40 cases. Primary arrhythmia events were confirmed within a first pass of cloud computing in the initial 72 hours on monitoring for all patients. Conclusions: We have demonstrated clinical feasibility of a cloud computing based ECG ambulatory monitoring system. The system holds promise in reducing overhead costs, and streamlining the clinician-computer interactions, required with standard Holter and Event monitoring systems. Use of the application using the iPad report interface which supports Holter, event monitoring and Mobile Cardiac Telemetry (MCT) should be evaluated in the near future. P898 Clinical and electrophysiological characteristics of children with chronic sinus tachycardia I. Vinogradova I. Vinogradova 1 St-Petersburg State Medical Pediatric University, Pediatric , Saint-Petersburg , Russian Federation T. Kruchina T. Kruchina 2 Federal Almazov Medical Research Centre , Saint-Petersburg , Russian Federation A. Adrianov A. Adrianov 1 St-Petersburg State Medical Pediatric University, Pediatric , Saint-Petersburg , Russian Federation O. Gordeev O. Gordeev 3 St-Petersburg Clinical Hospital 31 , Saint-Petersburg , Russian Federation D. Egorov D. Egorov 4 Saint-Petersburg State Medical University named I.P.Pavlov , Saint-Petersburg , Russian Federation Abstract Purpose: The aim of the study was to identify clinical and electrophysiological characteristics of children with chronic sinus tachycardia. Methods: 525 children with supraventricular tachycardia (SVT) were examined with chronic sinus tachycardia diagnosed in 23 children (10 boys and 13 girls). Mean age to the moment of the examination was 2,8±3,4 (3-17) years. Average duration of arrhythmia was 1,9±2,4 (0-8) years. Autonomic tone was estimated in all of the children. Examination included ECG, 24-hour Holter monitor, echocardiogram, treadmill test, transesophageal pacing study and pharmacologic autonomic blockade. Results: Chronic sinus tachycardia amounted to 4,4% among all SVT in children. Mean age of sinus tachycardia manifestation in boys was 12,1±3,6 (7-17) years, in girls – 10,2±4,0 (3-16) years. 77,3% of children had some complains: 47,8% had palpitations, 17% had physical exercises intolerance, and 12,5% of children had a history of syncope. In 22,7% arrythmia was asymptomatic and was found accidentally. On the ECG average heart rate amounted to 112,4±9,9 (100-133) bpm and exceeded upper normal age-dependent limit (more 98‰). On the 24-hour Holter monitor mean diurnal heart rate exceeded upper age-dependent limit, but nocturnal mean heart rate was normal. Autonomic tone was normal in 47,8% of children, sympatotonic in 43,5% of children, and vagotonic in 8,7% of children. On the echocardiograms left ventricular dilatation was found in 1 child only, and 28,6% of patients had mitral valve prolapse in combination with left ventricular abnormal chords. In transesophageal pacing study average sinus node recovery time (SNRT) was 741,3±120,1 (535-1000) ms, average corrected SNRT was 255,8±103,2 (73-450) ms; average maximal AV node conduction rate was 208,8±23,6 (180-280) impulses per minute. Accelerated AV node conduction (≥200 impulses per minute) was found in 12 children. 8 children underwent pharmacologic autonomic blockade during transesophageal pacing study (1% sol. obsidani 0,2 mg/kg IV+0,1% sol.atropini sulfatis 0,04 mg/kg IV). Two groups of children were formed after this trial: in 50% of children intrinsic heart rate was elevated and maximal AV conduction rate was less than 200 impulses per minute; in another half of the group intrinsic heart rate was normal and AV conduction was accelerated. Conclusions: Chronic sinus tachycardia accounts for 4,4% among all SVT in children; in 50% chronic sinus tachycardia is due to accelerated sinus node automacity and in 50% it is due to increased sympathetic impact on the regulation of the sinus node activity. P899 The value of anticardiac antibodies and cardiovascular magnetic resonance findings and in patients with dilated cardiomyopathy and conduction disturbances with structurally normal heart E.E. Efremov E.E. Efremov N.A. Mironova N.A. Mironova Russian Cardiology Research Center , Moscow , Russian Federation E.M. Gupalo E.M. Gupalo O.V. Stukalova O.V. Stukalova T.A. Malkina T.A. Malkina T.V. Sharf T.V. Sharf Abstract Purpose: To evaluate the the level of circulating autoantibodies and cardiovascular magnetic resonance (CMR) data in dilated cardiomyopathy (DCM) patients (pts) with ventricular arrhythmias and pts with conduction disturbances and structurally normal heart (CD). Methods: 27 pts with CD and structurally normal heart (11 male, mean age 40.7±11.4) and 35 pts with DCM (16 male, mean age 39.5±11.3) underwent Holter ECG monitoring with subsequent CMR with assessment of myocardial edema (ME), early gadolinium enhancement (EGE) and late gadolinium enhancement (LGE) with additional evaluation of gray zone. In serum of all pts persistence of autoantibodies to beta1-adrenergic receptor (β1-AAbs) and M2 muscarinic receptor (M2-AAbs) was evaluated. Results: CMR showed signs of ME in 14 (40%) DCM pts, EGE was positive in 10 pts (28.6%). The most frequent finding in DCM pts was LGE – in 15 pts (43%) (the volume of core zone was 22.8[16.95;51.1] cm3, the volume of gray zone was 38.3[10.15;88.8] cm3). Only 11 pts (31.4%) matched CMR criteria of inflammation (≥2 criteria) 27 (77%) of DCM pts have shown elevated level of IgGβ1-AAbs. LGE positive pts were characterized by higher number of ventricular premature complexes (VPC) (3643 [255;8500] vs 659 [64;2403] p=0.04) and higher level of β1-AAbs IgG (1.16 [0.71;2.05] vs 0.69 [0.54;0.93], p=0.019). None of CD pts revealed LGE at CMR. 5 (18.5%) of them had ME, 9 (33.3%) were EGE positive, 3 (11.1%) of them had 2 positive CMR criteria. 12 (44.4)% CD pts revealed enhanced level of IgM to M2-AAbs, while in DCM group it was positive only in 8 (34.8%) of pts. The titer of M2-AAbs was higher in CD group than in DCM pts (0.68[0.49;1.24] vs 0.55[0.43;0.86], p=0.04). β1-AAbs (IgG) were detected in serum of 68.6% of DCM pts and 31.4% pts were M2-AAbs (IgG) positive. The amount of β1-AAbs in DCM pts correlated with number of non-sustained ventricular tachycardia (VT), total amount of VPC, an d volume of myocardium with LGE (both core and gray zones) (r=0.71, 0.47, 0.61, 0.62 respectively). Conclusion: 77% DCM pts revealed enhanced level of IgG to β1-AAbs which correlates with total amount of VPC, number of VT and volume of myocardium with LGE. The level of IgM to M2-AAbs was elevated in 44.4% of CD pts. 11.1% of CD pts had 2 positive CMR criteria. The presence of IgM to M2-AAbs and CMR data might indicate the inflammatory etiology of conduction disturbances in pts with structurally normal heart. P900 Do ectopic supraventricular premature beats predict early new onset AF after CABG? A. Yaksh A. Yaksh 1 Erasmus Medical Center, Department of Cardiology , Rotterdam , Netherlands C. Kik C. Kik 2 Erasmus Medical Center, Cardiothoracic surgery , Rotterdam , Netherlands E.A.H. Lanters E.A.H. Lanters 1 Erasmus Medical Center, Department of Cardiology , Rotterdam , Netherlands U. Chigharoe U. Chigharoe 1 Erasmus Medical Center, Department of Cardiology , Rotterdam , Netherlands P. Knops P. Knops 1 Erasmus Medical Center, Department of Cardiology , Rotterdam , Netherlands M.J.B. Van Ettinger M.J.B. Van Ettinger 1 Erasmus Medical Center, Department of Cardiology , Rotterdam , Netherlands M.C.J. De Wijs M.C.J. De Wijs 1 Erasmus Medical Center, Department of Cardiology , Rotterdam , Netherlands P. Van De Kemp P. Van De Kemp 1 Erasmus Medical Center, Department of Cardiology , Rotterdam , Netherlands A.J.J.C. Bogers A.J.J.C. Bogers 2 Erasmus Medical Center, Cardiothoracic surgery , Rotterdam , Netherlands N.M.S. De Groot N.M.S. De Groot 1 Erasmus Medical Center, Department of Cardiology , Rotterdam , Netherlands Abstract Purpose: Early new-onset postoperative atrial fibrillation (PoAF) occurs frequently after CABG, but the exact mechanism is unknown. In the general population, frequent supraventricular premature beats (SVPB) are associated with AF. Whether SVPBs also play a role in development of PoAF is unknown. This study examines the frequency and burden of postoperative supraventricular ectopic beats (SVEBs) (SVPBs, SV-couplets/runs) in patients after CABG in relation to PoAF. Methods: Patients (N=105, 83 male, 66±9years) undergoing CABG were included. Postoperative continuous rhythms were recorded and semi-automatically analysed in multichannel Holter scanning software SynescopeTM (Sorin Group). SVEBs were defined as SVPBs (≥25% shorting of SVPB's cycle length (CL) compared to the average CL of the two preceding beats), couplets or runs (containing ≥3 beats and during <30 sec). PoAF was defined as episodes lasting ≥30 sec. SVPBs prematurity index (PI%) was assessed by dividing its CL to the averaged CL of the 2 preceding beats. SVPBs burden was obtained by dividing the sum of all SVPB by the total number of beats. The burden of couplets and runs was defined as the total duration of all couplets/runs divided by the recording time. The top 10th and 25th percentile of SVEBs characteristics were used to predict PoAF. Results: 42583846 beats recorded in 8231 hours were analysed. SVPBs, SV-couplets/runs and PoAF occurred in respectively 100%, 90%, 81% and 28% of the patients. Patients with PoAF had a significantly higher frequency and burden of SVEBs compared to patients without PoAF (Table 1). Using the SVEBs cut-off values PoAF could be predicted by SVPBs≥57/hour (OR:6.4), ≥1196/day (OR:8.4), SVPB burden≥1.2% (OR:6.1), SV-run≥0.2/hour (OR:5.1), ≥5/day (OR:4.7) and SV-run burden≥0.2% (OR:9.7). Conclusion: SVEBs occur in the majority of patients after CABG, whereas PoAF develops in 28%. Independent risk factors for development of PoAF were the frequency and burden of SVPBs and SV-runs. Hence, these parameters could be used to identify patients at risk for PoAF and allows preventive measures to be taken.  No PoAF PoAF P-value SVPB per day/burden (‰) 178/0.02 540/0.09 0.01/0.00 SV-couplet per day/burden (‰) 22/0.02 45/0.05 0.09/0.05 SV-run per day/burden (‰) 6/0.2 34/0.9 0.02   No PoAF PoAF P-value SVPB per day/burden (‰) 178/0.02 540/0.09 0.01/0.00 SV-couplet per day/burden (‰) 22/0.02 45/0.05 0.09/0.05 SV-run per day/burden (‰) 6/0.2 34/0.9 0.02   No PoAF PoAF P-value SVPB per day/burden (‰) 178/0.02 540/0.09 0.01/0.00 SV-couplet per day/burden (‰) 22/0.02 45/0.05 0.09/0.05 SV-run per day/burden (‰) 6/0.2 34/0.9 0.02   No PoAF PoAF P-value SVPB per day/burden (‰) 178/0.02 540/0.09 0.01/0.00 SV-couplet per day/burden (‰) 22/0.02 45/0.05 0.09/0.05 SV-run per day/burden (‰) 6/0.2 34/0.9 0.02  P901 Influence of electrode placement on localization of accessory pathway in patients with WPW syndrome Y.H. Kim Y.H. Kim J. Kim J. Kim Asan Medical Center, University of Ulsan College of Medicine , Seoul , Korea, Republic of S.H. Moon S.H. Moon Y.R. Kim Y.R. Kim J.P. Yun J.P. Yun J.H. Kwon J.H. Kwon M.S. Kim M.S. Kim U. Jo U. Jo G.B. Nam G.B. Nam K.J. Choi K.J. Choi Abstract Background: Vertical displacement of electrode V1 and V2 alters R/S ratio and anterior displacement of the arm leads results in the changes of R-wave amplitude. Incorrect electrode placement may alter the predictability of localization of accessory pathway (AP) in patients with Wolf-Parkinson-White (WPW) syndrome. Methods: We retrospectively analyzed 1228 surface ECGs from outpatient clinics (OPD-ECG) and electrophysiologic procedures (EPS-ECG) in 314 patients with supraventricular tachycardia (SVT: atrioventricular nodal tachycardia, atrioventricular tachycardia, typical atrial flutter) and 68 patients with WPW syndrome from 01/01/2012 to 31/12/ 2012. After the correction of lead placements by internal training session, we prospectively evaluated a total 450 ECGs in 150 patients with SVT and 27 patients with WPW syndrome between 01/04/2013 and 30/09/2013. Results: Fifty six (17.8%) of 314 SVT patients (age 49±18 years; 45.5% male) showed different R/S ratio in precordial leads and/or axis deviation in arm leads between the OPD-ECG and the EPS-ECG in 2012, while the error rate was siginificantly decreased to 19 (10.7%) of 158 SVT patietns in 2013 (P=0.037). In WPW syndrome, 17 (25.0%) of 68 patients showed the differences of R/S ratio and frontal axis in 2012, thereafter the careful electrode positioning, only 2 (7.4%) of 27 patients showed the differences of R/S ratio in precordial leads and the axis deviation in arm leads (P=0.085). Conclusion: Incorrect electrode placement is clinically common and alters the predictability of AP localization in patients with WPW syndrome. These deviations may potentially misdirect ablation of AP in patients with WPW. Careful positioning of electrodes is critical for better localizations of AP during electrophysiologic procedures. Examples of surface ECG in WPW P902 Description of extrasystoles in healthy pediatric subjects C. Bautista C. Bautista G. Sarquella Brugada G. Sarquella Brugada S. Cesar S. Cesar L. Marzo L. Marzo A. Berruezo A. Berruezo J. Brugada J. Brugada University Hospital Sant Joan de Deu , Esplugues de Llobregat , Spain Abstract The purpose of the study is to describe the morphology and origin of isolated extrasystoles found in healthy children. We have included 156 subjects, aged 1 month – 18 yo, who showed extrasystoles in their ECG. Subjects with underlying disease were excluded. Localization of site of the premature beats origin has been done using the QRS morphology on surface ECG. Results: Most of extrasystoles have a ventricular origin (84%) and a slight male preponderance (1.2 male: 1 female). There are no significant differences between age and origin of the premature beat. They originate in more than 1 area of the heart but are most common in the outflow tract area. Nearly 80% of premature beats originate form the right ventricular outflow tract that present with a distinct ECG pattern of left bundle branch block and inferior axis. Other common outflow tract sites include left ventricular outflow tract, the aortic sinuses of Valsalva, the area of aorto-mitral continuity or the superior basal septum near the His bundle. They all manifest an early precordial R-wave transition. Fascicular ventricular premature beats are very rare. Conclusion: Ventricular premature beats are more frequent than supraventricular extrabeats in children. Most of them can be classified to have an RVOT origin. It is important to distinguish these from those related to arrhythmogenic right ventricular cardiomyopathy because of different prognosis. Despite many morphological similarities, those originating in the LVOT can be accurately identified. P903 Arrhythmogenic right ventricular cardiomyopathy with epsilon waves in peripheral and precordial leads F. Candelmo F. Candelmo F. Rotondi F. Rotondi F. Alfano F. Alfano F. Manganelli F. Manganelli T. Lanzillo T. Lanzillo G. Amoroso G. Amoroso A. Caccavale A. Caccavale E. Ragno E. Ragno M.R. Pagliuca M.R. Pagliuca Department of Cardiology and Cardiovascular Surgery , Avellino , Italy Abstract A 43-year-old woman with a medical history of severe arrhythmogenic right ventricular cardiomyopathy (ARVC) was admitted to our hospital with symptoms of congestive heart failure. The patient had an implantable cardioverter defibrillator and was registered on the heart transplant waiting list. Standard 12-lead electrocardiogram (S-ECG) revealed sinus rhythm with heart rate of 40 bpm, PR = 200 ms, right frontal axis deviation, incomplete right bundle branch block, QTc interval prolongation (QT interval 0.600 msec; QTc interval 0.49 msec), T-waves inversion in V1–V6 and in I, II and aVF and small "epsilon waves" (EW) in the right precordial leads (Fig 1a). However, EW were clearly visible also in the peripheral leads, by quadrupling the sensitivity of the record (40 mm/mV) (Fig 1b). EW are low-amplitude waves localised between the end of the QRS complex and the beginning of the ST segment. EW are caused by postexcitation of the right ventricular myocardium and are considered a major diagnostic criteria for ARVC . The reported ECG prevalence of EW in ARVC ranges from 4% to 29%. They are usually seen only in leads V1 through V3. In our view, it is possible that detection of EW also in the limb leads, with a S-ECG, could be related to a severe and extensive involvement of the right ventricle. Our report suggest that the detection rate of EW in other leads beyond "classical leads" V1-V3 may be improved simply by increasing the sensitivity of S-ECG. epsilon waves P904 Repolarisation abnormalities in patients with alternant hemiplegia: a peculiar ECG for a rare entity G. Sarquella Brugada G. Sarquella Brugada C. Fons C. Fons S. Cesar S. Cesar J. Campistol J. Campistol L. Marzo L. Marzo C. Bautista C. Bautista J. Brugada J. Brugada University Hospital Sant Joan de Deu , Esplugues de Llobregat , Spain Abstract Alternant hemiplegia is a systemic channelopathy presenting with episodes of paresia or transient hemiplegia in different territories after intense emotions or stress. Genetic disorder has been identified by mutations in Na/K ATPase. Sudden death of unknown cause has been described in some cases. We decided to perform ECG to all patients followed in our National Reference Unit for neuromuscular diseases. Methods: all patients affected with alternant hemiplegia with known mutation in ATP1A3. Surface 12-lead ECG and echocardiography is performed in all cases. Results: 16 patients in the whole cohort of all national territory. We could obtain ECG of 11 of them. Out of these, 8 presented with T wave inversion in inferior leads and in right and septal precordial leads without QT interval prolongation. In one case, ventricular extrasystole with intraventricular delay is observed. Echocardiography excluded hypertrophy, dyskinesia, signs of fibrosis or structural disease. Conclusions: Alternant hemiplegia in a very rare disease associated with sudden death. Up to date, no characteristic ECG findings had been described. In our series, we observe a common ECG pattern in these patients that could be related to episodes of sudden death. Further studies are needed. P905 Clinical usefulness of baroreflex sensitivity test in the detection of cardiovascular autonomic neuropathy in patients with type 2 diabetes mellitus E. Borowik E. Borowik W. Grabowicz W. Grabowicz A. Lubinski A. Lubinski University Clinical Hospital Military Memorial Medical Academy – Central Veterans' Hospital , Department of Interventional Cardiology and Heart Rhythm Disorders , Lodz , Poland Abstract Introduction: Cardiovascular autonomic neuropathy (CAN) is one of the most common chronic complications of diabetes. It is defined as an impaired control of the cardiovascular system by the autonomic nervous system. The gold standard in detecting it is the Ewing test suite. The usefulness of other methods is still a subject of research. Goal: The goal of this study was to assess the clinical usefulness of baroreflex sensitivity (BRS) test in the detection of CAN in patients with type 2 diabetes mellitus. Material and Methods: The study included diabetic patients: 24 with CAN, diagnosed through the Ewing tests (the mean age 58±7 years, BMI 33.6±5 kg*m-2, HbA1c% 8.3±3, duration of diabetes 13.3±7 years), and 24 without CAN (56±8 years, BMI 32.2±5 kg*m-2, HbA1c% 9.1±2, 9.3±9 years, respectively). The control group consisted of 12 patients without diabetes, homogeneous regarding gender and age. BRS was assessed in the supine (L-BRS), and in the standing position (S-BRS). Results: L-BRS was lower in the group with CAN vs the non-CAN group (6.2±4 vs 9.6±4 ms/mmHg; p=0,009); S-BRS respectively (4.4±3 vs 6.9±4 ms/mmHg; p=0.02). BRS well differentiates patients with and without polyneuropathy. The highest sensitivity of L-BRS and S-BRS for detecting CAN is by cutoff ≤7ms/mmHg. Conclusions: The study confirms the value of baroreflex sensitivity in the early detection of CAN among patients with type 2 diabetes. We recommended cutoff points for BRS to detect CAN among patients with type 2 diabetes mellitus. P906 Cardiac sodium shannel variants are differentially tuned via tyrosine phosphorylation S.M. Iqbal S.M. Iqbal R. Lemmens-Gruber R. Lemmens-Gruber University of Vienna, Department of Pharmacology and Toxicology , Vienna , Austria Abstract Purpose: Post translational modifications such as, the process of phosphorylation and de-phosphorylation are known to finely modulate biophysical kinetics of voltage gated ion channels. During translational process alternative splicing of cardiac sodium channel NaV1.5 generate two major splice variants, characterized by the presence (Q-pre) or absence (Q-del) of glutamine at position 1077. Q-del accounts for 65%, while Q-pre accounts for 35% of total NaV1.5 population in human heart. It is reported that Fyn kinase a member of src-family tyrosine kinases is co-localized with NaV1.5 at adherens junctions in human heart and interacts with hH1 variant of NaV1.5 by phosphorylating tyrosine residue at position 1495. So, in present study we aimed to explore the involvement of potential tyrosine residue present at position 1495, in modulation of two major splice variants of NaV1.5 by Fyn kinase. Methods: HEK-293 cells were transiently transfected with either Q-del or Q-pre splice variants with or without Fyn kinase catalytically active (FynKa), Fyn kinase catalytically dead (FynKd) and FynKa+PP2 (src-family kinase blocker). Activation and inactivation kinetics of both splice variants were measured with patch clamp experiments by using whole cell configuration. A point mutation was introduced in both splice variants where tyrosine at position 1495 was replaced with phenylalanine and again activation and inactivation kinetics of mutant channel were measured by expressing either with FynKa, FynKd or with FynKa+PP2. Results: Half maximal activation and inactivation values from electrophysiological recordings indicate that fast inactivation of both splice variants were differentially modulated by Fyn kinase while activation remained unaffected. In Q-del there was hyperpolarizing shift of about 9mV, while in Q-pre there was depolarizing shift of about 8mV in inactivation curve. This shift in inactivation was reversed back when both splice variants were expressed with FynKd or with FynKa+PP2. Again mutant splice variant of NaV1.5 were differentially modulated by Fyn kinase where shift in inactivation was completely removed in Q-preY1495F mutant, but in case of Q-delY1495F hyperpolarizing shift in inactivation was reduced to 5mV. Conclusion: We can conclude from experimental evidence that NaV1.5 splice variants are differentially modulated by Fyn kinase, while tyrosine at position 1495 plays a critical role in modulation by completely removing the shift in Q-pre splice variant, but in Q-del it indicates potential involvement of other tyrosine residues in modulation. P907 Risk factors, incidence and efficacy of pharmacotherapy of ventricular arrhythmias and its impact on clinical outcomes in patients with acute coronary syndrome O. Kalejs O. Kalejs A. Maca A. Maca I. Zakke I. Zakke K. Trusinskis K. Trusinskis M. Zabunova M. Zabunova I. Mintale I. Mintale S. Jegere S. Jegere V. Stirna V. Stirna A. Erglis A. Erglis P.Stradins University Hospital, Latvian Center of Cardiology , Riga , Latvia Abstract Background: Life threatening ventricular arrhythmias (LTVA) are rare acute coronary syndrome (ACS) complication but with a significantly high mortality rate. At the moment, there are no defined risk factors of LTVA. Assess the rate of LTVA in patients with ACS and its types (ACS with ST segment elevations (ACS STEMI) and ACS without ST segment elevation (ACS NSTEMI)), the impact of the treatment on the rate of LTVA, as well as assessing the possible risk factors for the development of LTVA and its impact on clinical outcomes. Methods: Data from Latvian Acute Coronary syndrome register and data from patients, who have been hospitalized in Latvian Centre of Cardiology in the years 2011 – 2013. Descriptive statistical methods were used. Results: LTVA rate – ACS 4.2%; ACS STEMI 9.5%, ACS NSTEMI 2.0%. In ACS STEMI patients undergoing primary percutaneous coronary intervention (PPCI), LTVA rate is 12.3%, but in patients with fibrinolysis – 9.5% (p=0.95). Intrahospital mortality rate was higher in patient group with LTVA 28% vs 4.7% in patients without LTVA, p<0.001; ACS STEMI 28.4% vs. 7.6%, p<0.001; ACS NSTEMI 27% vs. 3.6%, p<0.001. In the group of patients who didn't have LTVA, there was a higher rate of arterial hypertension (AH) diagnosis (69,6% vs.49%, p<0.001), previous PCI (22.1% vs.12.9%, p=0.036), congestive heart failure (CHF) (35.2% vs.20.4%, p=0.004), previous use of beta adrenergic blockers (BAB) (27.2% vs.16.1%, p=0.020), angiotensin converting enzyme inhibitors (ACEI) (24.5% vs. 14,0%, p=0.022), use of statins (14.2% vs. 6.5%, p=0.035) before ACS. The risk factors of LTVA – higher Troponin I (92.39 vs. 14.60 ng/ml, p<0.001) and CK-MB fraction (204.10 vs. 25.80 ng/ml, p<0.00) maximal values, higher CK-MB fraction value in the first blood test after hospitalization (6.20 vs.4.60 ng/ml, p=0.056), lower left ventricular ejection fraction (45 vs.50%, p=0.001). Conclusions: LTVA are related to a significantly higher intrahospital mortality rates. There is a higher incidence of LTVA in patients with ACS STEMI. An early treatment of statins, BAB and aspirin decreases the risk of LTVA. The use of BAB, ACEI and statins before the onset of ACS possibly reduces the risk of LTVA. Patients who have data of previous AH, PCI and CHF show a less frequent development of LTVA. Most significant risk factors of LTVA are ACS STEMI, elevated Troponin I and CK-MB fraction maximal values, a higher CK-MB fraction level in the first blood test after hospitalization, as well as a decrease of the left ventricular ejection fraction P908 The prevalence of arrhythmias and conduction disorders in children with congenital heart disease undergone cardiac surgery correction A. Adrianov A. Adrianov A.V. Adrianov A.V. Adrianov L. Teslinova L. Teslinova I. Vinogradova I. Vinogradova Saint-Petersburg state university, Saint-Petersburg State Medical Pediatric University , Saint-Petersburg , Russian Federation Abstract The aim of the study is to analyze the incidence of arrhythmias and conduction disorders in children with congenital heart disease (CHD) undergone cardiac surgery correction. Methods: Complex clinical expert examination, analysis of experts' documentation, evaluation of clinical and functional disorders and level of disabilities for different types of CHD complicated with arrhythmias and conduction disorders. Characteristics of the clinical material. 57 children with CHD that undergone cardiac surgery correction were examined. In 33 children (57.8%) we revealed a variety of rhythm and conduction disturbances after the surgery interventions were performed in short-term or long-term postoperative period, including 17 (48.5%) boys and 16 (51.5%) girls. On average children were 9,4±3,8 years old (from 1 to 17 years old). The onset of an arrhythmia or a conduction disorder was in 1,5 to 4,2 years after the intervention (mean time 0,8+2,3 yeas). The CHD which were met are: enrichment of the pulmonary circulation – 24%, enrichment of the pulmonary circulation with cyanosis – 26%, reduction of pulmonary blood flow with cyanosis – 31%, stable hemodynamic of pulmonary circulation -19%. Daily monitoring of ECG was performed for 17 children (51.5%), 10 children (30.3%) were hospitalized and received appropriate examination and treatment for arrhythmia. Results: The conduction disorders we met were: sinus node dysfunction - 11 patients, total AV block - 2 patients, 1-2 degree AV block – 7 patients, intraventricular blocks – 9 patients, combined arrhythmias: 1 child. Two children with total AV block got a pacemaker implanted. Conclusion: It was found that 57.8% of children during the period of 1.5 to 4.2 years after surgical correction of their CHD develop arrhythmias or conduction disorders that require medication or surgical treatment. Identification of arrhythmias and conduction disorders, of course, may affect the determination of disability duration, rehabilitation forecast and rehabilitation potential. P909 Effects of worsening renal function on fibrin clot structure in atrial fibrillation patients receiving warfarin Y.C. Lau Y.C. Lau 1 University of Birmingham, University of Birmingham Centre for Cardiovascular Sciences , Birmingham , United Kingdom Q. Xiong Q. Xiong 2 Second Affiliated Hospital of Nanchang University , Nanchang , China, People's Republic of A. Blann A. Blann 1 University of Birmingham, University of Birmingham Centre for Cardiovascular Sciences , Birmingham , United Kingdom G.Y.H. Lip G.Y.H. Lip 1 University of Birmingham, University of Birmingham Centre for Cardiovascular Sciences , Birmingham , United Kingdom Abstract Introduction: Chronic kidney disease (CKD) is common amongst atrial fibrillation (AF) patients. While warfarin remains the mainstay treatment in stroke prevention in AF, the level of protection conferred against thrombosis is commonly counter-balanced by an increased bleeding risk among those with progressively worse renal function. This is possibly due to changes in fibrin clot structure. Coagulation and clot lysis can be assessed by Thrombelastography(TEG), fibrinolysis and turbidimetric assay. Methods: Blood samples from 153 AF patients with renal dysfunction, treated with warfarin, were collected and analysed by TEG, fibrinolysis and turbidimetric assay. Basic demographics and renal profile (inclusive of CKD status, Glomerular Filtraion Rate[GFR] and creatinine level) were also collected. Renal dysfunction is categorised into mild CKD(GFR 60 to >90) and moderate-severe CKD (GFR <60). All results are analysed by statistical methods involving t-test and Mann-Whitney test. Results: Using TEG, similar R-time was seen between moderate-severe and mild CKD subjects (7.05 minutes vs 7.58 minutes, p = 0.269). However, moderate-severe CKD is associated with shorter k-time (1.85 minutes vs 2.12 minutes, p = 0.018) and steeper α-angle (65.2° vs 61.5°, p = 0.027). A tendency towards formation of clot with larger maximum amplitude (MA) was observed (67.4 mm vs 64.2 mm, p = 0.076). However, there is no difference in percentage of clot-autolysis at 60 minutes. Turbidimetric assay confirmed the anticoagulation effect of warfarin with similar lag-time. Nevertheless, moderate-severe CKD is associated with greater rate of fibrin clot formation (RCF) (20.8 vs 16.2, p = 0.047). Fibrinolysis assay also showed steeper slope of fibrin clot lysis in moderate-severe CKD subjects (55.7 vs 41.5, p<0.0001) and a tendency for prolonged time to lyse 50% of fibrin clot (206 seconds vs 195 seconds, p = 0.095). Conclusions: Worsening renal function (with decreasing GFR and increasing creatinine level) is associated in increased thrombotic potential, as shown by altered coagulation with reduced time taken for conversion of fibrinogen to fibrin monomer (reduced k-time), steeper α-angle and increased rate of fibrin clot formation. This will explain the persistent increased incidence of stroke and systemic embolism among CKD patient with AF, despite adequate anticoagulation. As the resultant fibrin clot formed appears to be abnormal, with thicker fibres which are more sensitive to fibrin clot lysis, this will also explain the increased incidences of haemorrhage in anticoagulated subjects with renal dysfunction. P910 Left atrial appendage occluder for stroke prevention - the institut Jantung Negara (The national heart institute of Malaysia) watchman registry Z. Muhammad Z. Muhammad S. Khalea S. Khalea A. Hussein A. Hussein Z. Ali Z. Ali N. Mohd Saad N. Mohd Saad K.W. Koh K.W. Koh G.S. Tay G.S. Tay R. Rebo R. Rebo R. Omar R. Omar National Heart Institute, Cardiology , Kuala Lumpur , Malaysia Abstract Background: The safety and efficacy of left atrial appendage (Watchman) occluder device for patient not suitable for life long oral anticoagulants (OACs) for stroke prevention has been well established in recent clinical trials. Patients from Asia Pacific regions are not well represented in the current pool of data. Could the current evidence for Watchman therapy be translated in a real world experience? Objective: We sought to characterize the safety and efficacy outcomes of a single center experience with the Watchman device. Methodology: We conducted a prospective registry from July 2010 to August 2014. A total of 127 patients with non-valvular atrial fibrillation and CHA2DS2VASc score of at least 2 were screened. Inclusion criteria for implantation were: prior bleeding (33.0%), high risk of bleeding (27.0%), erratic INR (22.6%), and, poor compliance with medication (13.0%),and. Patients were followed up with a trans esophageal echocardiogram (TEE) at 45 days, 180 days and 360 days. All the safety and efficacy data were collected in our hospital's database. Results: A total of 115 (90.6%) suitable patients had successful implantation of the LAA occluder. The mean age was 68.1+11.8 years with mean left ventricle ejection fraction of 56.3+11.7%. There were 60 (59.4%) males, mean CHA2DS2VASc score of 4 and HASBLED score of 2.9. Most of patients were on OACs (72.3%) and dual antiplatelet therapy (11.9%) prior the implantation of the device. Majority of the patients were implanted with LAA occluder size 27mm (32.2%) and 24mm (24.3%). Majority (66.6%) were prescribed OACs post implant, followed by Double Anti Platelet in 29.8%. There was no incidence of pericardial effusion, however 2 (1.9%) patients developed non-major gastrointestinal bleed within 7 days of procedure. Complete endothelialization of LAA occluder was achieved in 97.3% of patients at 45 days, 97.8% at 180 days and 96.7% at 360 days with 94.5%, 91.9% and 96.0% of patients had oral anticoagulation withdrawn respectively. At 12 months follow-up, one patient (0.86%) had a stroke, none had systemic embolism and 7 patients (6.1%) had a cardiovascular or unexplained death. Conclusion: To date we have the biggest registry data for Watchman implant in the Asia Pacific region. The outcomes of our LAA occluder registry showed a comparatively safe and effective alternative therapy in preventing embolic events among non-valvular AF patients. P911 ICD therapies in the era of remote monitoring : follow-up of 881 patients with a very low rate of inappropriate therapies J.J. Ndjessan J.J. Ndjessan F. Dujenet F. Dujenet P. Defaye P. Defaye University Hospital of Grenoble , Grenoble , France P. Jacon P. Jacon N. Pellet N. Pellet A. Martin A. Martin H. Rekik H. Rekik Abstract Purpose: Remote monitoring (RM) is now accepted as a safe alternative to standard follow-up (FU) for ICD but little is known about rate of therapies in this population in real life. Methods: We analyzed the long term arrhythmic events and device-related outcomes of patients (pts) equipped with ICD/CRT-D and remote monitoring FU in our institution from 2008 to 2015. Pts were equipped with Boston (49%), Medtronic (39%), St Jude Medical (11%), Biotronik (3%) and Sorin (2%) RM systems. FU started after hospital discharge. Automatic FU with RM was performed every 3 months, with at least one standard FU (sFU)/year. In emergency cases, pts were invited for in-hospital control visits. ICD/CRT-D were programmed with 2 zones (VT zone >180 bpm / VF zone >220 bpm). All RM alerts and related EGMs as well as the reasons for therapies were reviewed by two physicians. Results: 881 pts (82% male, 64±11 y.o.) were enrolled. 49% had ischemic cardiomyopathy, 35% dilated cardiomyopathy, 38% previous history of AF, 64% were primary prevention ICD. CRT-D (46%) and dual chamber (43%) ICD were mainly represented, single chamber ICD 11%. During a FU period of 34±15 months, we noted 21±15 automatic RM FU and 2±2 sFU visits/patient. 110 pts died during FU (cardiac death 36%). 115 pts (13%) had major alerts: 53 ICD lead dysfunctions, 47 batteries depletions, 9 electrical storms, 6 therapies off. Among the 259 pts (29%) with minor alerts, 172 referred to AF, with for 76 pts early detection of unknown AF resulting in therapy modifications. Other minor alerts referred mainly to CRT (loss in biventricular pacing in 138 pts, high LV lead impedance in 6 pts). Appropriate therapies (app) occurred in 204 pts (23%): 376 app shocks occurred in 97 pts (11%), and 5684 app ATPs in 184 pts (21%). Inappropriate therapies occurred in 41 pts (5%). 74 inappropriate shocks occurred in 29 pts (3%) and were mainly due to supraventricular tachycardia (AF 52%, atrial tachycardia 10%, sinus tachycardia 14%, lead dysfunction 10%, T over sensing 7%, electromagnetic interference 3%). 285 inappropriate ATPs occurred in 26 pts (3%), due to AF in 50% of cases. Conclusion: In a large single center observational study, RM has demonstrated to be an effective method of FU for ICD recipients. Early diagnoses of AF or lead failure allow rapid management of patients and are associated with a very low rate of inappropriate shocks. P912 Patterns of newly detected atrial fibrillation and antithrombotic treatment in Europe (GLORIA-AF Phase II) G.Y.H. Lip G.Y.H. Lip 1 University of Birmingham, Professor of Cardiovascular Medicine, Centre for Cardiovascular Sciences , Birmingham , United Kingdom H.C. Diener H.C. Diener 2 University Hospital Essen, University Duisburg-Essen, Department of Neurology, , Essen , Germany S.J. Dubner S.J. Dubner 3 Clinic and Maternity Suizo Argentina , Buenos Aires , Argentina J.L. Halperin J.L. Halperin 4 Mount Sinai School of Medicine , New York , United States of America C.S. Ma C.S. Ma 5 Beijing Anzhen Hospital, Cardiology Department, Atrial Fibrillation Center , Beijing , China, People's Republic of K.J. Rothman K.J. Rothman 6 RTI Health Solutions , Research Triangle Park , United States of America K. Zint K. Zint 7 Boehringer Ingelheim GmbH, Corporate Department Global Epidemiology , Ingelheim , Germany A. Elsaesser A. Elsaesser 8 Boehringer Ingelheim Corporation, Clinical Trial Portfolio , Burlington , Canada C. Teutsch C. Teutsch 9 Boehringer Ingelheim Pharma GmbH & Co. KG, Medicine TA Cardiology , Ingelheim , Germany M.V. Huisman M.V. Huisman 10 Leiden University Medical Center , Leiden , Netherlands Abstract Purpose: Anticoagulants (vitamin K antagonists [VKAs] or non-VKA oral anticoagulants [NOACs]) are recommended for patients with non-valvular atrial fibrillation (AF) and additional risk factors for stroke, regardless of the AF pattern. We assessed antithrombotic treatment in relation to AF pattern and stroke risk in routine care in Europe. Methods: Patients with newly identified AF and stroke risk (CHA2DS2VASc score ≥1) were enrolled in the global GLORIA-AF Registry Program and data on initial antithrombotic therapy were collected. This cross-sectional analysis presents treatment according to AF type and stroke risk. Results: A total of 4,703 patients were enrolled in Europe between Nov 2011 and Feb 2014. Median age: 73 years, 47.2% were female, 72.7% had hypertension, 21.3% diabetes mellitus, and 88.4% had a high stroke risk (CHA2DS2VASc scores ≥2). AF was paroxysmal in 45.4% (n = 2134), persistent in 38.8% (n = 1827), and permanent in 15.7% (n = 740). Of the patients with high stroke risk and paroxysmal AF, 88.8% (n = 1670) were treated with oral anticoagulants as compared to 93.0% (n = 2116) of high-risk patients with persistent/permanent AF. In patients with moderate stroke risk (male and CHA2DS2VASc =1) and paroxysmal or persistent/permanent AF, 81.6% (n = 168) and 88.5% (n = 231) received oral anticoagulation, respectively. The figure shows the initial antithrombotic therapy by AF type and stroke risk. Conclusions: In the first years of NOAC availability in Europe a high proportion of patients with moderate or high stroke risk received appropriate oral anticoagulation. Antithrombotic practices did not fully reflect guideline recommendations as overall patients with permanent or persistent AF more often received oral anticoagulation as compared to patients with paroxysmal AF. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email:


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POSTER SESSION 3, EP Europace, 2015, iii108-iii131, DOI: 10.1093/europace/euv166