Epicardial Substrate Ablation in Gene-Negative Brugada Syndrome

BACKGROUND: Epicardial ablation for Brugada syndrome targeting abnormal right ventricular outflow tract (RVOT) substrate with local abnormal ventricular activity (LAVA) demonstrated efficacy in European trials but remains uncommon in the United States. CASE SUMMARY: A 51-year-old man with type II Brugada pattern, febrile syncope, inducible ventricular fibrillation, and negative genetic testing declined implantable cardiac-defibrillator implantation. Electroanatomic mapping revealed local abnormal ventricular activation in the RVOT epicardium. Procainamide provoked type I Brugada pattern and prolongation of local RVOT activation. Radiofrequency ablation eliminated LAVA and normalized the electrocardiogram. DISCUSSION: Dynamic correlation of accentuated LAVA with procainamide provocation of type I Brugada pattern implicates delayed depolarization as the mechanism for pseudo-ST-segment changes in Brugada syndrome.