B-AB22-01 UTILITY OF PROLONGED DURATION ENDOCARDIAL ABLATION FOR SUCCESSFULLY TARGETING CHALLENGING VENTRICULAR ARRHYTHMIAS ORIGINATING FROM THE LEFT VENTRICULAR SUMMIT REGION

Abstract

Catheter ablation (CA) of ventricular arrhythmias (VAs) originating from the left ventricular summit (LVS) region can be challenging. Different mapping and ablation strategies have been utilized to target these VAs. We sought to explore whether prolonged duration (PD) radiofrequency ablation (RFA) from adjacent endocardial locations can improve CA outcomes of LVS VAs. Patients undergoing CA of LVS VAs from 01/2016-12/2019 were included. Standard RFA approach involved incremental power titration (20-45W) over 60-120 seconds with irrigated tip catheter to achieve 10% impedance drop. In cases where VAs could not be suppressed with standard RFA or had late suppression, lesion application was extended beyond 120 seconds (PD; for 3-5 minutes). Procedural success was defined as complete suppression of targeted VA ≥30 min post ablation We also analyzed clinical and ECG characteristics (see Table) to identify any predictors for patients requiring standard versus PD RFA. One hundred and two patients (60±14 years, 61% male) were included (standard RFA in 80 and PD RFA in 38). Procedural success was achieved in 54 patients with standard and 32 patients with PD RFA (68% vs. 84%; p=0.05). Two pericardial effusions occurred (1 in each group). Patients in whom standard RFA was successful had better LV function (see Table) and were more likely to have R/S ratio >1 in lead I (63% versus 34% for PD RFA; p value=0.05). Prolonged duration RFA from adjacent endocardial locations is a safe and effective technique for successfully targeting challenging LVS VAs that fail standard RFA.