521The impact of genetic mutations on ventricular tachycardia substrate types and ablation outcome in patients with non ischemic cardiomyopathy

Abstract

Background: There are limited data on the prevalence of genetic mutations associated with malignant ventricular tachycardia (VT) in patients with non-ischemic cardiomyopathy (NICM) referred for VT ablation. In addition, the impact of pathogenic mutations on the arrhythmogenic substrate localization and ablation outcome has not yet been investigated.Methods: Eighty-nine patients (56±15years; 84% male, LV ejection fraction 38±13%) with NICM referred for ablation of recurrent sustained VT and a predominantly left sided arrhythmogenic substrate between 2008-2017 were included. All patients underwent electroanatomical voltage mapping (EAVM) and testing of 55 NICM-related genes using next generation sequencing. EAVM data were analyzed with regard to uni (<7.95mV) - and bipolar (<1.5mV) low-voltage areas with fragmented, double and late potentials in order to determine the scar-related substrate for VT. Patients were followed for VT recurrence and mortality. Patients with (likely) pathogenic mutations were compared to patients with either no mutations or with variants of unknown significance (VOUS).