Catheter ablation of symptomatic idiopathic ventricular arrhythmias
Neth Heart J
Catheter ablation of symptomatic idiopathic ventricular arrhythmias
A. W. G. J. Oomen 0 1
L. R. C. Dekker 0 1
A. Meijer 0 1
0 Catharina Hospital , Eindhoven , The Netherlands
1 A. W. G. J. Oomen
Aims This study was designed to gain insight into the patient characteristics, results and possible complications of ablation procedures for symptomatic idiopathic premature ventricular complexes (PVC) and idiopathic ventricular tachycardia (VT). Methods Data were collected from all patients who underwent radiofrequency catheter ablation for symptomatic PVCs and idiopathic VT in the Catharina Hospital between 1 January 2011 and 31 December 2015. The procedural endpoint was elimination or non-inducibility of the clinical arrhythmia. Successful sustained ablation was defined as the persistent elimination of at least 80% of the PVCs or the absence of VTs at follow-up. In case of suspected PVC-induced cardiomyopathy, the systolic left ventricular function was reassessed 3 months post procedure. Results Our cohort consisted of 131 patients who underwent one or more ablation procedures; 99 because of symptomatic premature ventricular complexes, 32 because of idiopathic VT. In total 147 procedures were performed. The procedural ablation success rate was 89%. Successful sustained ablation rate was 82%. Eighteen (13.2%) patients had suspected PVC-induced cardiomyopathy. In 15 of them (83%), successful sustained ablation was achieved and the left ventricular ejection fraction improved from a mean of 39% (±8.8) to 55.4% (±8.1). Most arrhythmias originated from the right ventricular outflow tract (60%) or aortic cusps (13%). Complications included three tamponades. Conclusion Catheter ablation therapy for idiopathic ventricular arrhythmias is very effective with a sustained success rate of 82%. In patients with PVC-induced cardiomyopathy, it leads to improvement of systolic left ventricular function. However, risk for complications is not negligible, even in experienced hands.
Catheter; Ablation; Idiopathic; Premature; Ventricular; Tachycardia
● Catheter ablation for symptomatic premature ventricular
beats and idiopathic ventricular tachycardia is very
● In case of PVC-induced cardiomyopathy, the systolic LV
function will improve after a successful catheter ablation.
● The complication rate of catheter ablation for the
abovementioned indications is, however, not negligible.
● Doctors should be aware of this treatment option in case
of frequent PVCs or idiopathic VT, especially in patients
with LV dysfunction.
Premature ventricular complexes (PVCs) and ventricular
tachycardia (VT) occurring in the absence of structural
heart disease are referred to as idiopathic ventricular
arrhythmias. Frequent PVCs occur in 1–4% of the general
]. Usually these PVCs do not cause symptoms
and patients without structural heart disease have a good
]. However, some patients can be highly
]. Furthermore, in the last decade, it has been
increasingly recognised that frequent PVCs can lead to
reduced systolic left ventricular (LV) function (PVC-induced
cardiomyopathy) . Idiopathic VT accounts for
approximately 10% of all VT diagnoses [
]. Idiopathic ventricular
arrhythmias occur in specific locations of the heart and the
causative mechanisms can be triggered activity, re-entry or
Medication is often used as the first-line option to
suppress these idiopathic ventricular arrhythmias. This therapy
is, however, often limited by lack of efficacy or not tolerated
because of side effects [
Radiofrequency ablation of PVCs and idiopathic VT
has evolved as a safe and effective treatment for
symptomatic idiopathic PVCs/VT or PVC-induced
cardiomyopathy. According to the 2015 European Society of
Cardiology guidelines, catheter ablation is recommended in
patients with symptomatic right ventricular outflow tract
(RVOT) PVC/idiopathic VT after failed or not preferred
antiarrhythmic medical therapy or if RVOT PVCs contribute
to reduced LV ejection fraction (LVEF) (Class I, level of
evidence B). In case of symptomatic PVCs/VT originating
from the LVOT, aortic cusp or epicardium, catheter ablation
should be considered after failed antiarrhythmic medical
therapy (Class IIa, level of evidence B) [
In this study, we present the patient characteristics,
results and complications of catheter ablation procedures for
symptomatic idiopathic PVCs and idiopathic VT in a single
This is a single-centre, observational study among
consecutive patients who underwent a catheter ablation
procedure because of symptomatic idiopathic PVCs or VT
between 1 January 2011 and 31 December 2015. Patients
were highly symptomatic and/or had presumed
PVC-induced cardiomyopathy. Patients were not included if they
were scheduled for an ablation but did not actually
undergo this procedure. Patients were older than 18 years, able
to read and sign informed consent. All patients underwent
screening for structural heart disease prior to the ablation
procedure. Patients with ischaemic heart disease,
significant valvular disease, genetic or infiltrative cardiomyopathy
were excluded from this database. The volume and
function of the right ventricle were examined and ECGs were
scrutinised to exclude any possible patients with
arrhythmogenic right ventricular cardiomyopathy (ARVC).
Significant coronary artery disease had to be ruled out by cardiac
angiography or stress testing in all patients.
LV function and PVC burden
Patients underwent a routine pre-procedural work-up by
determining LV function and PVC burden. LV function was
assessed by echocardiography using the Simpson formula
or by MRI. When both techniques were used, we selected
MRI ejection fraction. An LVEF below 51% was
Also, Holter monitoring was performed at baseline to
assess the PVC burden. This was done 3 months
pre-procedure. PVC burden was defined as the number of PVCs as
percentage of the total beats per 24 h.
All antiarrhythmic drugs were withdrawn at least 5
halflives prior to the procedure except for amiodarone. All
studies were performed by one of two experienced
operators. PVCs or VTs were mapped using activation mapping
if they occurred frequently or pace mapping if they were
not frequent. If few or no PVCs were observed at baseline,
programmed ventricular stimulation was performed with
intravenous administration of isoproterenol to induce PVCs
or VT. Mapping and ablation was guided by the CARTO
electro-anatomic mapping system (Biosense Webster,
DiamondBar, CA, USA) using a 3.5 mm irrigated-tip
ablation catheter. From April 2012 on, contact-force ablation
catheters were used. For left-sided procedures, systemic
heparinisation was used to maintain an activated clotting
time of 300–350 s. After ablation, patients were monitored
for at least 30 min to ensure successful ablation.
Procedural ablation success (PAS) was defined as elimination or
non-inducibility of the clinical arrhythmia. One focus was
treated in each procedure. After an effective ablation, all
antiarrhythmic drugs were discontinued.
Patients were routinely seen in the outpatient clinic
3 months after the procedure. Holter monitoring was
repeated then in the majority of patients. Successful sustained
ablation (SSA) was defined as the persistent elimination of
at least 80% of the PVC burden or the absence of VTs. In
patients in whom Holter recording was not available post
ablation, absence of complaints was considered successful
In case of LV dysfunction, assessment of LV function
was also repeated after 3 months. PVC-induced
cardiomyopathy was defined as a systolic LVEF of below 51% which
improved after successful ablation.
Continuous variables are presented as the mean ± standard
deviation. PVC burdens are presented as the median and
interquartile range due to their skewed distribution.
Categorical variables are presented as total number and
percentages. To compare two variables a paired t-test or Wilcoxon
signed-rank test was used. Proportions were compared
In total 131 consecutive patients (mean age: 51 years) were
included. Most patients were female (64%). All patients
were symptomatic, had LV dysfunction or both. Ninety-nine
patients (76%) had frequent PVCs, 32 patients (24%)
presented with idiopathic VT. They underwent in total 147
ablation procedures. In one ablation procedure, the epicardium
was targeted while all other procedures were endocardial
In 30 patients (23%), the ablation procedure was the
firstline treatment. Drug treatments before the ablation
procedure are shown in Tab. 1. Eight patients (6%) had already
undergone a catheter ablation procedure for idiopathic VT
or PVCs before 2011. These procedures were not recorded
in this database.
Procedural ablation success was achieved in 131 of the
147 ablation procedures (89%) (Tab. 2). In 10 procedures
(7%) procedural ablation success was not accomplished, in
6 procedures (4%) this was unclear, mainly because of lack
of PVCs at the start of the procedure.
A single procedure was performed in 118 patients. In
11 patients, a second procedure was needed while there
were 2 patients in whom a third and a fourth procedure
were performed, respectively. The mean follow-up was
10.5 months (±7.3). Successful sustained ablation was
achieved in 108 patients (82%).
Holter registration both pre-and post-ablation was
available in 90 of 99 patients with PVCs. The
pre-procedural median PVC burden per 24 h in these patients was
15.5% (interquartile range 9–30). In patients with systolic
LV dysfunction, the PVC burden was 25.5%
(interquartile range 12–33). The median PVC burden after one or
more ablation procedures was 0.14% (interquartile range
0.01–1.1). This decrease in PVC burden is significant
(p = 0.001). The median burden at follow-up in patients
with procedures with any procedural ablation success or
successful sustained ablation was 0.1% (interquartile range
0.01–0.8) and 0.05% (interquartile range 0.01–0.3),
respectively (Fig. 1).
In 13 patients, one or more redo procedures (in total 16)
were performed. In 8 patients (9 redo procedures), the same
region was targeted as during the previous procedure. In 4
of those patients, a lack of PVCs was reported during the
first catheter ablation. In 3 patients (3 redo procedures), the
site of origin was found to be located in the aortic cusp
while during a previous procedure the RVOT was targeted.
after 1 or more ablation procedures
patients with any procedural success
patients with SSA
Left posterior fascicle
One patient underwent 3 redo procedures with eventually
a successful endo-epicardial ablation. PVCs that differed
from the previously ablated PVCs were found in 1 patient
(1 redo procedure).
The vast majority of PVCs and VT originated from the
RVOT (88 procedures, 60%) with significantly less
arrhythmias originating from the aortic cusps (19 procedures, 13%)
and other parts of the heart such as the LV outflow tract,
Purkinje fibres, epicardium or mitral valve annulus (Fig. 2).
In patients with LV dysfunction, RVOT (n = 7, 39%) and
aortic cusps (n = 7, 39%) constituted the most prevalent sites
of origin (Fig. 3). This difference in distribution is not
significant (p = 0.317).
There was no significant difference in successful
sustained ablation with respect to the origin of the PVCs/
idiopathic VT (p = 0.451). Contact-force ablation catheters
were used in the majority of procedures (88%) with no
statistical difference (p = 0.322) in the procedural outcome
between the use of contact-force catheters and non-contact
Eighteen patients had LV dysfunction. The mean systolic
LV function in those patients was 39% (±8.8). In 15
patients (83%) successful sustained ablation was achieved and
in all those patients the LV function recovered. The
systolic LV function in patients with pre-existent impaired LV
function improved significantly to a mean of 55.4% (±8.1)
(p = 0.001) after one or more ablation procedures (Fig. 4).
In the patients without successful sustained ablation, the LV
function did not change.
Fig. 4 LVEF before and after
one or more ablation procedures
for PVCs in case of left
ventricular dysfunction. Full lines
show the LVEF for patients with
sustained successful ablation
(SSA), dashed lines show the
LVEF for patients without SSA
LVEF before ablation procedure
LVEF after SSA
Of note is that the mean heart rate in the patients with
LV dysfunction before (69 beats/min, ±7) and after ablation
(70 beats/min, ±7) was not significantly different.
Complications occurred in 5 patients (3.8%): 3
tamponades of which 2 were drained percutaneously and 1
surgically, 1 with abdominal bleeding which was managed
conservatively and 1 third-degree atrioventricular (AV) block
requiring implantation of a permanent pacemaker. There
were no fatal complications. Both the abdominal bleeding
and the third-degree AV block were caused by using a
noncontact force ablation catheter.
Two of the tamponades occurred while ablating a focus
in the RVOT using a contact force catheter (one because of
a steam pop). The other tamponade occurred using a
noncontact force catheter ablating a focus at the mitral annulus.
The present study shows a high success rate for catheter
ablation for symptomatic idiopathic ventricular arrhythmias
with a procedural success rate of 89% and a sustained
successful ablation rate of 82%. The percentage of successful
sustained ablations in patients with LV dysfunction was
83% in our series. Importantly in all patients with LV
dysfunction and successful sustained ablation, the LV function
improved. The risk of complications is low though not
negligible, even in experienced hands.
Our results are in accordance with earlier reports in the
literature. Over the last years several studies on ablation
for symptomatic idiopathic PVCs/VT have been published
with success rates of over 80% and low complication rates
4, 7, 9, 10
]. Results of PVC ablation in patients with LV
dysfunction are also good. A meta-analysis showed
longterm success rates of up to 80% in the majority of included
studies and a relatively low risk of complications (no more
than 8%) .
What this study adds to the aforementioned reports is
that it includes a sizable real-life cohort of patients covering
a long period of 5 years. Most other studies are smaller and
focused solely on RVOT arrhythmias. Studies that report
the results of catheter ablation of idiopathic PVCs/VTs from
other origins are sparse and the majority included fewer
patients. This study included all-comers and was not restricted
to a certain site of origin of the arrhythmia. Therefore, it
gives relevant insights into real-life practice of catheter
ablation of idiopathic ventricular arrhythmias.
Successful ablation was associated with improvements
in LV function and LV dimensions, both in our study and
in the literature [
4, 10, 12, 13
]. The improvement in LV
function presumably has prognostic consequences. This
improvement is not only true for patients with PVC-induced
cardiomyopathy but also for patients with ‘PVC worsened’
]. In other words; the improvement
of LV function after successful ablation of frequent PVCs
may be independent of the presence of structural heart
The underlying mechanism of PVC-induced
cardiomyopathy is uncertain. Ventricular dyssynchrony and
irregularity are potential causes. One of the initial hypotheses
was that PVC-induced cardiomyopathy was a
tachycardiainduced cardiomyopathy. However, in this study, the mean
heart frequency in the patients with improved LV function
was not significantly different before and after ablation. The
heart rate during the pre-procedure Holter registrations may
have been influenced by the use of antiarrhythmic drugs
while all Holter registrations following ablation procedures
were performed in patients off any antiarrhythmic drugs.
It is also not entirely clear yet how to identify those
patients with LV dysfunction who will benefit from PVC
ablation. Patients with wider PVC complexes, higher PVC
burdens (from 10%) and a longer duration of symptoms
might benefit more. Some studies suggest that PVCs from
the right ventricle carry more risk to develop LV
dysfunction but these findings could not be confirmed in larger
11, 16, 17
The ventricular outflow tracts are the most common
origins of idiopathic PVC/VT [
]. Also in our series, the
majority of our patients presented with outflow tract
arrhythmias. Remarkable is the difference in distribution of
sites of origin between patients with normal versus
diminished LV function. Due to the spread and the relatively low
numbers, this is not significantly different but it is
something worth investigating further.
In our study, complications occurred in 5 patients, with
tamponade in 3 of them. This relatively high percentage
of tamponade may be due to the learning curve and the
fragility of the RVOT. There was no significant difference
in the risk of tamponades between contact force versus
noncontact force ablation catheters. It is important to note that
there were no fatal complications and that the percentage
of complications is in line with other studies. For example,
Valk et al. reported 4% haemodynamically important
pericardial effusions after 82 ablations of idiopathic PVCs and
VTs in the outflow tracts using non-contact force ablation
Steam pops occur infrequently in ventricular ablation. In
a series of over 4,000 ablation lesions, steam pops occurred
in 62 lesions (1.5%). Larger falls in impedance and higher
maximum energy are associated with pops [
The mean follow-up in this study was 10.5 months which
may be relatively short. We cannot exclude recurrences
occurring after the follow-up period. There are no guidelines
about how long the follow-up should be. However, given
that this treatment is solely intended to reduce symptoms
and is a curative treatment in patients without structural
heart disease, we feel there is no need for longer follow-up
in those patients.
Several limitations are worth noting. This was a
single-centre study with one of two experienced operators performing
the ablation procedures. Outcomes may therefore differ in
other centres with lower volumes. Due to the study design
patients were not included, and therefore not reported, in
this study if no PVCs or VTs were seen or inducible during
the procedure. There is no uniformly accepted definition of
successful sustained ablation. Therefore, results may differ
in other studies using another definition of this endpoint.
Defining success by at least 80% reduction of PVCs after
the ablation procedure was introduced previously by Penela
et al. [
]. As this procedure is primarily aimed at
reducing symptoms, we added the absence of symptoms to this
Another limitation is that Holter follow-up data were not
available for all patients. Nonetheless, we think that also the
subjective results in patients without Holter follow-up are
important because the ablation procedure is primarily aimed
at reducing symptoms.
In most procedures, a contact-force ablation catheter was
used. Although we did not find any statistical differences in
outcome with the different types of ablation catheters, it is
not unimaginable that there would be a difference if more
non-contact force catheters had been used.
We tried our best to exclude patients with structural heart
disease. However, the diagnosis of ARVC only relies
partially on imaging and ECG criteria. Therefore, although
unlikely, we cannot entirely exclude the possibility that
some patients with ARVC may have been included in this
Finally, in 2 patients with LV dysfunction, the ablation
was not successful. In those patients, the LV function did
not change after the procedure. We cannot exclude dilated
cardiomyopathy that was not related to frequent PVCs in
Although this is a retrospective study with its inherent
limitations, we studied consecutive patients representing
a real-world cohort of patients who are candidates for
ablation according the current guidelines. We therefore think
that our findings are valuable for current everyday practice.
In this study we demonstrated that catheter ablation is an
effective and relatively safe treatment for patients with
symptomatic frequent PVCs or idiopathic VT. Furthermore,
patients with LV dysfunction due to the arrhythmia can be
cured by successful catheter ablation. This presumably has
prognostic consequences for these patients. It is therefore
important that doctors are aware of this treatment option
in case of frequent PVCs or idiopathic VT, especially in
patients with LV dysfunction.
Acknowledgements The authors thank M. van ’t Veer for his
contribution to the statistical analysis.
Conflict of interest A.W.G.J. Oomen, L.R.C. Dekker and A. Meijer
declare that they have no competing interests.
Open Access This article is distributed under the terms of the
Creative Commons Attribution 4.0 International License (http://
creativecommons.org/licenses/by/4.0/), which permits unrestricted
use, distribution, and reproduction in any medium, provided you give
appropriate credit to the original author(s) and the source, provide a
link to the Creative Commons license, and indicate if changes were
1. Kostis JB , McCrone K , Moreyra AE , et al. Premature ventricular complexes in the absence of identifiable heart disease . Circulation . 1981 ; 63 : 1351 - 6 .
2. Kennedy HL , Whitlock JA , Sprague MK , et al. Long-term followup of asymptomatic healthy subjects with frequent and complex ventricular ectopy . N Engl J Med . 1985 ; 312 : 193 - 7 .
3. Van Huls van Taxis CF , Piers SR , de Riva SM. Fatigue as presenting symptom and a high burden of premature ventricular contractions are independently associated with increased ventricular wall stress in patients with normal left ventricular function . Circ Arrhythm Electrophysiol . 2015 ; 8 : 1452 - 9 .
4. Bogun F , Crawford T , Reich S , et al. Radiofrequency ablation of frequent, idiopathic premature ventricular complexes: comparison with a control group without intervention . Heart Rhythm . 2007 ; 4 : 863 - 7 .
5. Calvo N , Jongbloed M , Zeppenfeld K. Radiofrequency catheter ablation of idiopathic right ventricular outflow tract arrhythmias . Indian Pacing Electrophysiol J . 2013 ; 13 : 14 - 33 .
6. Lerman BB , Stein KM , Markowitz SM . Mechanisms of idiopathic ventricular tachycardia . J Cardiovasc Electrophysiol . 1997 ; 8 : 571 - 83 .
7. Ling Z , Liu Z , Su L , et al. Radiofrequency ablation versus antiarrhythmic medication for treatment of ventricular premature beats from the right ventricular outflow tract: prospective randomized study . Circ Arrhythm Electrophysiol . 2014 ; 7 : 237 - 43 .
8. Priori SG , Blomström-Lundqvist C , Mazzanti A , et al. ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death . Eur Heart J . 2015 ; 36 : 2793 - 867 .
9. Adams JC , Srivathsan K , Shen WK . Advances in management of premature ventricular contractions . J Interv Card Electrophysiol . 2012 ; 35 : 137 - 49 .
10. Lamba JL , Redfearn DP , Michael KA , Simpson CS , Abdollah H , Baranchuk A . Radiofrequency catheter ablation for the treatment of idiopathic premature ventricular contractions originating from the right ventricular outflow tract: a systematic review and metaanalysis . Pacing Clin Electrophysiol . 2014 ; 37 : 73 - 8 .
11. Zang M , Zhang T , Mao J , Zhou S , He B . Beneficial effects of catheter ablation of frequent premature ventricular complexes on left ventricular function . Heart . 2014 ; 100 : 787 - 93 .
12. Yokokawa M , Good E , Crawford T , et al. Recovery from left ventricular dysfunction after ablation of frequent premature ventricular complexes . Heart Rhythm . 2013 ; 10 : 172 - 5 .
13. Wijnmaalen AP , Delgado V , Schalij MJ , et al. Beneficial effects of catheter ablation on left ventricular and right ventricular function in patients with frequent premature ventricular contractions and preserved ejection fraction . Heart . 2010 ; 96 : 1275 - 80 .
14. Penela D , Van Huls Van Taxis C , Aguinaga L , et al. Neurohormonal, structural, and functional recovery pattern after premature ventricular complex ablation is independent of structural heart disease status in patients with depressed left ventricular ejection fraction: a prospective multicenter study . J Am Coll Cardiol . 2013 ; 62 : 1195 - 202 .
15. El Kadri M , Yokokawa M , Labounty T , et al. Effect of ablation of frequent premature ventricular complexes on left ventricular function in patients with nonischemic cardiomyopathy . Heart Rhythm . 2015 ; 12 : 706 - 13 .
16. Del Carpio Munoz F , Syed FF , Noheria A , et al. Characteristics of premature ventricular complexes as correlates of reduced left ventricular systolic function: study of the burden, duration, coupling interval, morphology and site of origin of PVCs . J Cardiovasc Electrophysiol . 2011 ; 22 : 791 - 8 .
17. Baman TS , Lange DC , Ilg KJ , et al. Relationship between burden of premature ventricular complexes and left ventricular function . Heart Rhythm . 2010 ; 7 : 865 - 9 .
18. Valk SD , de Groot NM , Szili-Torok T , et al. Clinical characteristics and acute results of catheter ablation for outflow tract ventricular tachycardia or premature beats . J Interv Card Electrophysiol . 2012 ; 35 : 301 - 9 .
19. Seiler J , Roberts-Thomson KC , Raymond JM , et al. Steam pops during irrigated radiofrequency ablation: feasibility of impedance monitoring for prevention . Heart Rhythm . 2008 ; 5 : 1411 - 6 .