Abstract 15371: Clinical Impact of the Number of Extrastimuli and Minimal Coupling Interval in Programmed Electrical Stimulation in Patients with Brugada Syndrome
Methods: PES was conducted from 2 right ventricular sites with a maximum of 3 ventricular extrastimuli in consecutive 102 Brugada syndrome patients (98 men, age 46±12 years old, 26 with ventricular fibrillation(VF), 40 with syncope, and 40 asymptomatic). Minimal coupling interval of extrastimulus was 180 msec. The induction of VA was defined as an induction of ventricular fibrillation (VF) or non-sustained polymorphic ventricular tachycardia (>15 beats). Patients with VA induced by sigle or double extrastimuli were assigned to Group-A, and by triple extrastimuli to Group-B. Prognosis of patients was compared among procedures of PES and clinical subgroups.
Results: VA was induced in 74 patients (VF in 64, and PVT in 10), in 4 by single extrastimulus, 37 by double extrastimuli, and 33 by triple extrastimuli. During 82±48 months of follow-up, 22 patients had lethal arrhythmic events (AE; VF or sustained ventricular tachyarrhythmia). Although the total inducibility of VA was not associated with increased risk of AE (16/74 vs 6/28, log-rank P=0.78), patients in Group-A had worse prognosis than those in Group-B (14/41 vs 2/33, log-rank P=0.003). Kaplan-Meier analysis in patients without previous VF also showed that Group-A had poorer outcome than Group-B (7/30 vs 0/25, log-rank P=0.011). In asymptomatic patients, only 1 of Group-A developed AE. Though VA was induced easier by extrastimuli with coupling interval ≥ 200 msec in Group-A than in Group-B (19/40 vs 25/31, P=0.01), the prognosis was not different between patients with and without induced VA by longer coupling interval (8/44: <200msec vs 8/30: ≥ 200 msec, log-rank P=0.40).
Conclusions: The number of extrastimuli (single and double paired / triple paired) by PES was related to prognosis of patients with Brugada syndrome. Our data indicated that the easier inducibility can be a predictor of poor outcome.
- © 2010 by American Heart Association, Inc.