Role of signal-averaged electrocardiograms in arrhythmic risk stratification of patients with Brugada syndrome: A prospective study

Abstract

Arrhythmic risk stratification in patients with Brugada syndrome remains controversial. Several recent reports have highlighted the possible role of late potential (LP) on the signal-averaged electrocardiogram (SAECG) as a noninvasive risk stratification tool in Brugada syndrome, but further prospective study is required before its general applicability. The purpose of this study was to investigate the role of LP in arrhythmic risk stratification of Brugada syndrome patients. Forty-three patients with Brugada syndrome were enrolled and divided into a symptomatic group (group A, n = 24) and an asymptomatic group (group B, n = 19). SAECG was performed to analyze the characteristics of LP in all subjects. The prospective study was conducted to observe the occurrence of arrhythmic events. LP was positive in 22 (91.7%) of 24 patients in the symptomatic group and in 7 (36.8%) of 19 patients in the asymptomatic group. During mean follow-up of 33.8 +/- 9.0 months, the incidence rate of arrhythmic events was 72.4% (21/29) in LP-positive [LP(+)] patients compared with 14.3% (2/14) in LP-negative [LP(-)] patients. Multivariate Cox proportional hazard analyses revealed that the presence of LP had the most significant hazard ratio of 10.9 (95% confidence interval 1.1-104.3, P = .038), with sensitivity of 95.7%, specificity 65.0%, positive predictive value 75.9%, negative predictive value 92.9%, and predictive accuracy 81.4%. Kaplan-Meier curves plotted for event-free survival according to LP showed a significant difference between LP(+) and LP(-) patients (log rank, P = .003). The results of this study support the role of LP detected by SAECG in arrhythmic risk stratification of Brugada syndrome patients.