Abstract 19979: Epicardial Delayed Potentials Guided Electrophysiological Study at Ventricular Outflow Tracts in Brugada Syndrome

Background: Risk stratification for VF with programmed electrical stimulation (PES) has not been established in Brugada syndrome. We measured epicardial delayed potentials (epi-DPs) at left and right ventricular outflow tracts (LVOT and RVOT), and examined the contribution to PES-induced and spontaneous VF. Methods and Results: Forty two cases with Brugada syndrome (41 male, 43±13 years, 17 symptomatic) underwent PES at high right atrium, RV apex, RVOT-endocardial and epicardial (via conus branch of right coronary artery) sites, and LVOT-epicardial site (via anterior inter-ventricular vein). Epi-DPs were defined as local conduction delay and fragmented ventricular waves at epicardial sites of OTs. For VF induction, the minimal coupling interval of extra stimuli was kept > 200 ms. (1) 16 of 42 cases (41%) showed PES-induced VF. Among them, 12 cases with epicardial sites-originated VF had epi-DPs, while 4 cases with endocardial sites-originated VF did not. In 26 cases without PES-induced VF, only two had...