PO-05-035 FASCICULAR SUBSTRATE MODIFICATION TO TREAT HUMAN VENTRICULAR FIBRILLATION: A MULTICENTER STUDY

Abstract

Purkinje fibers play an important role in initiation and maintenance of ventricular fibrillation (VF). Fascicular substrate modification approaches have been suggested to treat recurrent VF in isolated case reports and small case series. To investigate the outcomes of catheter-based fascicular substrate modification to treat recurrent VF. Out of 2,212 consecutive patients with ventricular arrhythmia undergoing catheter ablation at our centers, 18 (0.81%) underwent fascicular substrate modification by targeting with short (<20 s) RF lesions in the most distal segment of the Purkinje fibers as identified with high-density mapping during sinus rhythm. Demographic, clinical, and follow-up characteristics were prospectively collected in our institutional database. A total of 18 patients (mean age: 56±3.8 years, female: 4, 22%) were included in the study. Of those, 11 (61.1%) had idiopathic VF (normal heart VF), 3 (16.7%) had non-ischemic cardiomyopathy and 4 (22.2%) had mixed cardiomyopathy. Average LVEF was 42.5%. Patients had failed ≥2 antiarrhythmic drugs pre-ablation. At baseline, all patients had inducible VF and non-inducibility of VF at the end of the procedure was achieved in 16 (88.9%) patients. In select patients, remapping revealed elimination of the targeted Purkinje potentials. At the end of the procedure, no patient demonstrated new evidence of fascicular block or bundle branch block. VF initiation and final lesion sets are shown in figure 1. There were no procedure-related complications. After a median follow-up of 24 months, 16 (88.9%) patients were arrhythmia-free on- or off-drugs; 11/11 (100%) patients with normal heart VF vs 5/7 (71.4%) with underlying cardiomyopathy (p=0.06). Catheter ablation of human VF with distal fascicular substrate modification is feasible, safe and appears highly effective with high rates of acute VF non-inducibility and long-term freedom from recurrent VF.