B-PO02-127 OUTCOMES OF CATHETER ABLATION OF VENTRICULAR ARRHYTHMIAS ORIGINATING FROM A LEFT VENTRICULAR FALSE TENDON

Abstract

Left ventricular false tendons (LV-FT) are chord-like fibromuscular structures that cross the LV cavity and attach between the septum, papillary muscles (PM), or the free wall. Ventricular arrhythmias (VAs) arising from LV-FT have been described in isolated case reports, but data on larger cohorts of patients are insufficient. We investigated the prevalence, electrophysiologic features and outcomes of catheter ablation of LV-FT VAs. We screened 3719 patients undergoing ablation of VAs at our institution between January 2011 and August 2020. Diagnosis of LV-FT origin of the VA was based on detailed activation/pace-mapping guided by intracardiac echocardiography (ICE). A total of 16 (0.4%) patients (age 60±15 years, LVEF 38±16%) with LV-FT VAs were identified. Of these, 9 (56%) had focal PVC/VT from the LV-FT and 7 (44%) scar-related monomorphic VT with critical circuit elements involving the LV-FT. The most common anatomical locations of the LV-FT were between the posteromedial PM and LV septum, between the anterolateral and posteromedial PM and between the LV apex and the mid-septum. Purkinje potentials in sinus rhythm were recorded on the LV-FT at the VA target site in only 1 case. Acute ablation success was achieved in 15 (94%) patients (Figure). After a median follow-up of 1.5 years, the targeted LV-FT VA recurred in 4 (31%). The LV-FT can be a rare site of origin of focal VAs or may contain critical circuit elements of scar-related VTs. Mapping and catheter ablation guided by ICE is successful in eliminating LV-FT VAs in most cases.