Abstract 20611: Prevention of Ventricular Fibrillation Episodes in Brugada Syndrome by Catheter Ablation over the Anterior Right Ventricular Epicardium
Background: We hypothesized that in Brugada syndrome (BrS) patients, the substrate site is the right ventricular outflow tract (RVOT); abnormal electrograms would be identified at this location, which would serve as the target site for catheter ablation.
Methods: We studied 9 symptomatic BrS patients (all males; mean age 39 years) who had multiple ICD discharges due to recurrent ventricular fibrillation (VF) episodes (4 ± 1.5 per month). Detailed epicardial and endocardial mapping of arrhythmogenic substrate of the right ventricle, as well as epicardial mapping of the left ventricle was performed during sinus rhythm. Electrophysiologic studies including programmed stimulation and radiofrequency ablations over the arrhythmogenic substrate sites were performed.
Results: All patients had typical Brugada ECG pattern and inducible ventricular tachycardia (VT)/VF; they were found to have unique abnormal low voltage (0.91+ 0.97mV), prolong-duration (130 + 45 msec) and fractionated late potentials (104+41 msec beyond QRS complex) clustering exclusively in the anterior aspect of the RVOT epicardium and not seen anywhere else. Ablation at these sites rendered VT/VF non-inducible (7 of 9 patients [78%]; p =0.0023) and normalization of the Brugada ECG pattern in 89% (P<0.001). Long-term outcomes (17± 6 months) were excellent, with no recurrent VT/VF in all patients off medication (except one patient on amiodarone).
Conclusions: Abnormal delayed depolarization over the anterior RVOT epicardium is the main underlying electrophysiologic mechanism in BrS patients. Ablation over this area of the RVOT results in normalization of the Brugada ECG pattern and prevents recurrent VT/VF episodes in BrS patients.
- © 2010 by American Heart Association, Inc.