Ablation of idiopathic ventricular arrhythmias from the right ventricular apex

Idiopathic ventricular arrhythmias (VAs) from the right ventricle (RV) are well-described, but limited data exist regarding those from the RV apex.

The purpose of this study was to define the electrocardiographic (ECG) characteristics and ablation outcomes of RV apical VAs, including premature ventricular contractions (PVCs) and ventricular tachycardia.

Patients undergoing catheter ablation for RV apical VAs at 3 centers were retrospectively analyzed. VAs from the moderator band, papillary muscles, or associated with significant structural heart disease were excluded. Clinical characteristics, ECG features, procedural details, and follow-up data were assessed.

12 patients were included (4 (33%) with PVCs, 7 (58%) with monomorphic ventricular tachycardia, and 1 (8%) with PVCs triggering ventricular fibrillation). All VAs exhibited a left bundle branch block pattern with a left superior axis and negative concordance. The mean QRS duration was 167 ± 14 ms. Nine patients (75%) underwent a single ablation procedure, 2 (17%) required 1 repeat procedure, and 1 (8%) required 2. Endocardial ablation was effective in 8 patients (67%), with 4 (33%) requiring endocardial and epicardial ablation. After a median follow-up of 57 months (interquartile range 12-74 months) in 11 patients, 10 (91%) remained free of recurrence (7 by rhythm monitoring and 3 by symptom resolution). 1 patient (9%) required antiarrhythmic therapy for recurrence; all others remained off therapy. One implantable cardioverter-defibrillator was extracted after successful ablation. Of the 2 patients with suspected PVC-induced cardiomyopathy, 1 fully recovered and 1 progressed to heart failure requiring transplantation, despite normal cardiac magnetic resonance imaging and PVC suppression.

RV apical VAs demonstrate a distinctive ECG morphology that aids localization. Catheter ablation is effective but may require an epicardial approach.