Dual-Sided Ablation Strategy for the Moderator Band in Refractory Premature Ventricular Contraction Triggered Ventricular Fibrillation

Background:
Premature ventricular contractions (PVCs)–triggered ventricular fibrillation (VF) can originate from the moderator band (MB). Ablation can be challenging, particularly when culprit PVCs are absent during the procedure, and the complex anatomy of the MB may result in incomplete lesion formation and arrhythmia recurrence.

Subjective:
to evaluate the feasibility and clinical outcomes of an empirical anatomy-guided dual-Sided ablation strategy (Figure 1) targeting the MB in patients with refractory PVC-triggered VF.

Methods:
This retrospective study included patients with recurrent, drug-refractory, PVC-triggered VF originating from the MB, as identified by electrocardiographic findings and prior ablation procedures. In the absence of inducible PVCs or VF, or an identifiable arrhythmogenic substrate, an empirical dual-sided ablation was performed along the superior and inferior aspects of the MB. Lesion sets were delivered from opposing sides of the structure to achieve more complete elimination of the arrhythmogenic trigger.

Results:
Six patients were included. No patient exhibited inducible PVCs or ventricular arrhythmias during the electrophysiological study, and no discrete arrhythmogenic substrate was identified. Dual-sided MB ablation was successfully completed in all patients. After ablation, the mean right ventricular free-wall activation delay was 12 ± 5 ms. No procedural complications occurred, and no changes in electrocardiographic or echocardiographic parameters were observed. During a median follow-up of 26.5 months (IQR 17.0–31.0), no VF recurrences or VF-related hospitalizations were observed.

Conclusion:
In patients with MB-triggered VF-storm or recurrent VF, empirical dual-sided ablation of the MB may provide durable arrhythmia suppression even when PVCs are not inducible during the procedure.