Electrophysiological Characteristics and Ablation Outcomes in Patients With Catecholaminergic Polymorphic Ventricular
Lishui Shen1,2, Shangyu Liu1,3, Feng Hu4
1Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases Chinese Academy of Medical Sciences and Peking Union Medical College Beijing China.
Background:
Catheter ablation of premature ventricular contractions (PVCs) that trigger polymorphic ventricular tachycardia (PVT) or ventricular fibrillation has been reported as a novel therapy to reduce the syncope events in patients with catecholaminergic PVT, whereas the long-term ablation outcome and its value in improving exercise-induced ventricular arrhythmias remain unclear.
Methods And Results:
Fourteen consecutive selected patients with catecholaminergic PVT (mean±SD age, 16±6 years; 43% male patients) treated with maximum β-blockers with no possibility of adding flecainide were prospectively enrolled for catheter ablation. The primary end point was syncope recurrence, and the secondary end point was the reduction of the ventricular arrhythmia score during exercise testing. Twenty-six PVT/ventricular fibrillation-triggering PVCs were identified for ablation. The trigger beats arose from the left ventricle in 50% of the cases and from both ventricles in 36% of the cases. Purkinje potentials were observed at 27% of the targets. After a mean follow-up of 49 months after ablation, 8 (57%) patients were free from syncope recurrence. Ablation of trigger beat significantly reduced the syncope frequency (mean±SD, 4.3±1.6 to 0.5±0.8 events per year; P<0.001) and improved the ventricular arrhythmia scores at the 3-month (5 [range, 3-6] to 1.5 [range, 0-5]; P=0.002) and 12-month (5 [range, 3-6] to 2 [range, 0-5]; P=0.014) follow-ups. The induction of nontriggering PVCs postablation was closely associated with syncope recurrence (hazard ratio, 6.8 [95% CI, 1.3-35.5]; P=0.026).
Conclusions:
Catheter ablation of PVT/ventricular fibrillation-triggering PVCs in patients with catecholaminergic PVT who cannot receive flecainide treatment seems to be a safe and feasible adjunctive treatment that may reduce the syncope burden and improve exercise-related ventricular arrhythmias. Induction of nontriggering PVCs after ablation is associated with a higher risk of syncope recurrence.
Insights
Catheter ablation effectively reduced syncope and improved exercise-induced arrhythmias in patients with catecholaminergic polymorphic ventricular tachycardia (CPVT). However, non-triggering PVCs post-ablation indicate a higher risk of syncope recurrence.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Interventions
Background:
- Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare genetic disorder characterized by exercise-induced ventricular arrhythmias.
- Catheter ablation of premature ventricular contractions (PVCs) triggering polymorphic ventricular tachycardia (PVT) or ventricular fibrillation is a novel approach for CPVT.
- Long-term outcomes and efficacy in improving exercise-induced arrhythmias require further investigation.
Purpose of the Study:
- To evaluate the long-term outcomes of catheter ablation in patients with CPVT.
- To assess the impact of ablation on syncope recurrence and exercise-induced ventricular arrhythmias.
- To identify predictors of syncope recurrence after ablation.
Main Methods:
- Prospective enrollment of 14 consecutive CPVT patients treated with maximum beta-blockers and ineligible for flecainide.
- Catheter ablation targeting PVCs that trigger PVT/ventricular fibrillation.
- Primary endpoint: syncope recurrence; Secondary endpoint: reduction of ventricular arrhythmia score during exercise testing.
- Mean follow-up of 49 months.
Main Results:
- 57% of patients were free from syncope recurrence after a mean follow-up of 49 months.
- Ablation significantly reduced syncope frequency (4.3 to 0.5 events/year) and improved exercise-induced ventricular arrhythmia scores.
- Induction of non-triggering PVCs post-ablation was associated with a higher risk of syncope recurrence (HR 6.8).
Conclusions:
- Catheter ablation is a safe and feasible adjunctive treatment for CPVT patients ineligible for flecainide.
- Ablation can reduce syncope burden and improve exercise-related ventricular arrhythmias.
- Post-ablation non-triggering PVCs predict syncope recurrence, highlighting the need for continued monitoring.
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