Elimination of Local Abnormal Ventricular Activities

TLDR

Catheter ablation of ventricular tachycardia is effective, yet the optimal endpoint for substrate modification remains unclear due to limitations of noninducibility. The study hypothesizes that eliminating local abnormal ventricular activities during sinus rhythm or pacing can serve as an effective endpoint for VT ablation. Seventy patients with structural ventricular disease underwent high‑density endocardial and epicardial mapping, and ablation targeted LAVA using an irrigated‑tip catheter via transseptal, retrograde aortic, or subxiphoid approaches. LAVA were present in 95.7% of patients, successfully eliminated in 70.1%, and their removal independently predicted a lower risk of recurrent VT or death (HR 0.49) and improved long‑term survival.

Abstract

Catheter ablation of ventricular tachycardia (VT) is effective and particularly useful in patients with frequent defibrillator interventions. Various substrate modification techniques have been described for unmappable or hemodynamically intolerable VT. Noninducibility is the most frequently used end point but is associated with significant limitations, so the optimal end point remains unclear. We hypothesized that elimination of local abnormal ventricular activities (LAVAs) during sinus rhythm or ventricular pacing would be a useful and effective end point for substrate-based VT ablation. As an adjunct to this strategy, we used a new high-density mapping catheter and frequently used epicardial mapping.Seventy patients (age, 67±11 years; 7 female) with VT and structurally abnormal ventricle(s) were prospectively enrolled. Conventional mapping was performed in sinus rhythm in all, and a high-density Pentaray mapping catheter was used in the endocardium (n=35) and epicardially. LAVAs were recorded in 67 patients (95.7%; 95% confidence interval, 89.2-98.9). Catheter ablation was performed targeting LAVA with an irrigated-tip catheter placed endocardially via a transseptal or retrograde aortic approach or epicardially via the subxiphoid approach. LAVAs were successfully abolished or dissociated in 47 of 67 patients (70.1%; 95% confidence interval, 58.7-80.1). In multivariate analysis, LAVA elimination was independently associated with a reduction in recurrent VT or death (hazard ratio, 0.49; 95% confidence interval, 0.26-0.95; P=0.035) during long-term follow-up (median, 22 months).LAVAs can be identified in most patients with scar-related VT. Elimination of LAVAs is feasible and safe and is associated with superior survival free from recurrent VT.