Abstract 11738: Epicardial Connections as an Etiology in Recalcitrant Tachyarrhythmias After Left Atrial Ablations in Patients With Persistent Atrial Fibrillation

Abstract

Introduction: Left atrial radio frequency ablation(RFA) for persistent atrial fibrillation(AF) and left atrial tachycardias(LAT) are often challenging due to the presence of epicardial connections(EC). Hypothesis: Mapping and subsequent ablation of epicardial connections using high density(HD) mapping and activation patterns leads to successful termination of persistent AF and LAT. Methods: We studied 40 patients who were found to have epicardial connections as determined by HD mapping, missing isochrones and activation patterns. All patients underwent antral ablation for pulmonary vein isolation (PVI). LAT were remapped using Advisor HD Grid catheter. Results: At baseline, the mean age and BMI was 74±6.4 and 33.5±5.8 respectively. Out of 40 patients with EC, 21 were associated with the Vein of Marshall (Figure 1), 4 were associated with Septo-pulmonary bundles(figure 2), 6 were associated with the Bachman Bundle(Figure 3) and 9 were associated with Septo-atrial bundles. Acutely, endocardial ablation opposite to the epicardial connection sites achieved success with PVI, Posterior Wall Isolation(PWI) and termination of LAT. Conclusions: EC significantly contributes to the failure of PVI, PWI and the reorganization of LAT. Rigorous mapping of the connecting bundles using HD mapping helps target the ablation sites for successful outcomes.