A15-4 New insight into neurocardiogenic syncope: brain oxygenation and electroencephalography monitoring

EP Europace, Dec 2003

Szufladowicz, E., Kozluk, E., Dobrogowska-Kunicka, J., Zbiec, A., Maniewski, R., Walczak, F.

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A15-4 New insight into neurocardiogenic syncope: brain oxygenation and electroencephalography monitoring

0 B. Verheyden , F. Beckers, F. Kubben, K. Vandorpe, T. Reybrouck, H. Ector, A.E. Aubert. Dept 1 E. Szufladowicz', E. Kozluk', .I. Dobrogowska-Kunicka', A. Zbi& , R. Maniewskiz, F. Walczak' 2 J.L. Newton , P.T. Donaldson, SW. Parry , R.A. Kenny, C.M. Morris. Cardiovascular Investigation Unit, Royal Victoria Injirmary , Newcastle , & School 3 National Institute 4 H. Evrengul', H. Evrengulz, V T&i', D. Dursunogluz. 'DI: Behcet &Sick Children Is Hospital , Division ity) as an index of cerebrovascular resistance. Data are presented as m e a n & SD. Results: In the 13 tilt-positive patients (68%), EEG alterations during the prodromic and the syncopal phase were different a m o n g cardioinhibitory, mixed and vasodepressive types. No EEG alterations in tilt-negative patients. TCD demonstrated a significant PI increase at the onset of prodromic symptoms in comparison with baseline (2.01&0.94 vs. 0.77&0.20, p<O.OOl, paired-sample t-test). No TCD alterations in tilt-negative patients. Furthermore, the percentage change in PI with respect to baseline was signiiicantly higher in cardioinhibitory types (254&51%, 5 patients) than in mixed and vasodepressive ones (101&22%, 8 patients) @<O.OOl, independent-sample t-test). Conclusions: Our data show that the degree of cerebral vasoconshiction at the onset of prodromic symptoms changes with the positivity type of tilt test. W e suggest that the amount of sympathetic activation, (as hypothesized by Levine during graded Lower Body Negative Pressure in healthy humans), may cause the degree of cerebral vasoconshiction in N M S patients. Therefore the sympathetic modulation of cerebral vasoconshiction may be a turning point for the explanation of N M S pathophysiology. - I Al 5 3 ANGIOTENSIN-CONVERTING ENZYME INSERTION/DELETION POLYMORPHISM DIAGNOSED VASOVAGAL SYNCOPE AND TILT Vasovagal syncope (WS) is a common cause of syncope characterised by hypotension with or without bradycardia that results in cerebral hypoperfusion and resultant collapse with loss of consciousness. VVS is a disease that clusters in families and recent studies by OUTgroup suggest that VVS may have a significant heritable component (Xs:lOSO) (Newton et al., CAR 2003). Salt supplementation appears to improve orthostatic tolerance and increases baroreceptor sensitivity in patients with VVS and hence polymorphisms of the angiotensin-converting enzyme (ACE, DCPI) would be a plausible potential candidate for regulating some of the features of the disease. The aim of this study was to examine the frequency of the ACE insertion/deletion polymorphism in a large cohort of well-character&d patients with a definite diagnosis of VVS. DNA was collected prospectively from 165 unrelated patients attending the Cardiovascular Investigation Unit who had VVS diagnosed on the basis of an abnormal haemodymmic response during head up tilt in conjunction with symptom reproduction. Overall there was no significant difference in the distribution of the ACE insertion or deletion gene frequencies in cases compared to a large (>6000 subjects) national control population. Cases controls: This study suggests that polymorphisms of ACE alone are not associated with VVS. Further studies are planned to clarify the genotype/phenotype relationship in VVS and examine other candidate genes. I Al 5 4 N E W INSIGHT INTO NEUROCARDIOGENIC BRAIN OXYGENATION AND ELECTROENCEPHALOGRAPHY MONITORING SYNCOPE: Introduction: Near-infrared spectroscopy (NIRS) measure brain oxygenation (hemoglobin-HbO, Deoxygenated-Hb, total-HbT), eeg indicates disturbances of brain electrical activity. Aim of study: To present changes in NIRS and eeg during neurocardiogenic syncope (NS). Material and method: Study group 54 patients with history of syncope. 54 tilt tests (33 female, m e a n age 33 -1-18 years): Neurocardiogenic synape occurred in 42 pts. Control group 37 healthy volunteers (22 female, m e a n ag(30& 12). Neurocardiogenic syncope didn’t occurred in control group. Results: Control group- EEG didn’t change during tilt test in any patient. NIRS during m e a n time of 7 minutes after changing to up-right position we were observed in all pts. slow decrease of HbO curve with corresponding increase of Hb curve. This drop range between 10.15% (mean 11%) from the basal lines and stay stable to the end of the test. Study group In pts. with NS changes in NIRS proceed changes in blood pressure and heart rate (2,1&2,7 minutes). W e observed 3 types of curves: 1. Similar corresponding drop of HbO and HbT (10 pts); 2. Drop of HbO without decrease of HbT (5 pts); 3. Mixed (27 pts). Hb level increased 0,9&1,7 min. after HbO dropped. EEG in pts. with NS we observed slowing down of eeg activity (theta>delta) in 29 pts. with further suppression in 6 pts. No changes in eeg were in 7 pts. Conclusions: 1. During NS typical changes in brain NIRS monitoring proceed changes in heart rate, blood pressure and syncope. 2. Changes in eeg occur simultaneously with syncope. 3. The most deep changes in eeg are observed in cardiodepressive type of NS. 4. In some pts. changes in NIRS and eeg are present in prolong time after NS while pts. are already conscious and having normal heart rate and blood pressure. I Al 5 5 AUTONOMIC CARDIOVASCULAR RESPONSES TO ORTHOSTATIC STRESS IN VASO-VAGAL SYNCOPE PATIENTS: EFFECTS OF TILT TRAINING Introduction: The purpose of this pilot study is to evaluate the influence of tilt training in vasovagal syncope (VVS) patients on autonomic balance using indices of heart rate and blood pressure variability (HRV and BPV) and baroreflex sensitivity (BRS). Methods: 23 subjects (13 females and 10 males) consisting of a control group (N=lO, aged 23&5 ys), a patient group (N=5, aged 38&9 yrs) and a training group (N=S, aged 33&5 yrs) performed the Westminster tilt test protocol. The training group consisted of VVS-patients that were enrolled in a tilt-training program @ehveen 3 and 12 sessions). The tilt test was positive in 3 subjects from the training group and in all subjects of the patient group. Continuous ECG and blood pressure were recorded simultaneously. Low frequency (LF: 0.04-0.15 Hz) and high frequency (HF: 0.16-0.4 Hz) powers in heart rate and blood pressure were calculated for 3 tilt phases: supine rest (10 min), 10 minutes after tilt and 5 minutes recovery. BRS was assessedusing the sequencemethod. Results: Results did not show any difference between male and female subjects. Both HF and LF powers of HRV were higher in the control group compared to the patient group. In the control group LF power of BPV was increased after tilt compared to supine rest whereas in the patient group LF power of BPV remained unchanged. BRS tended to be higher at supine rest in the control group compared to the patient group (NS) and decreased signficandy after tilt only in the control group (P<O.O5). BRS in the training group tended to increase (NS) with increasing tilt sessions. Conclusion: Cardiac autonomic control and vammotor sympathetic reflex activity is suggested to be impaired in VVS-patients. Low BRS at supine rest is proposed to be a predictor of increased risk for VVS. Tilt training showed a general reconditioning of dynamic cardiovascular regulation in VVS-patients. SPECTRAL AND TIME DOMAIN RATE VARIABILITY DURING TABLE TESTING IN CHILDREN MEDIATED SYNCOPE ANALYSES OF HEART HEAD-UPRIGHT TILT WITH NEURALLY Denizli, Neurocardiac syncape (NS) is a common cause of syncope in children. The mechanism, though related to abnormalities in autonomic function, has not been fully elucidated, particularly in pediatric patients. This study assessedthe heart rate variability (HRV) response to head-upright tilt table test (HUT) in children with NS and normal volunteers. Spectral and time domain analysis of HRV was used to assesschanges in autonomic function in 27 children (9 male, m e a n age 12.3&1.6 years) with a history of at least one episode of syncope and positive passive HUT and 27 age-matched normal volunteers with negative passive HUT before and during postural tilt and to attempt to relate such changes to specific types of haemodynamic response to tilt. Frequency domain measurements of the high (HF) and low (LF) frequency bands and the ratio LF/ HF were derived from bolter recordings, computed by Fast Fourier Analysis for 5 min intervals. Time domain measurements of the SDNN, SDNNI, SDANN, RMSSD and triangular index were derived from 24 hours bolter recordings. There were no significant differences between clinical characteristics, time domain and basal frequency domain parameters of the groups. M e a n values of LF and LF/HF ratio were increased and HF was decreased signiiicantly in response to tilting in both patient and control groups. M e a n values of LF and LF/HF ratio were higher and HF was lower compared to controls immediately after tilting. LF and LF/HF ratio showed a statistically significant decrease and a significant increase in HF during syncope in patients. The three subgroups of patients had similar patterns of changes in autonomic activity. The results of this study show that syncopal patients have a different pattern of response to the tilting test although the basal autonomic function was similar compared to the controls. The syncopal patients have exaggerated response to the tilting

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Szufladowicz, E., Kozluk, E., Dobrogowska-Kunicka, J., Zbiec, A., Maniewski, R., Walczak, F.. A15-4 New insight into neurocardiogenic syncope: brain oxygenation and electroencephalography monitoring, EP Europace, 2003, B23, DOI: 10.1016/eupace/4.Supplement_2.B23-a