Prevalence of early repolarization pattern in inferolateral leads in patients with Brugada syndrome

Abstract

Background: Recent data have shown a high incidence of the early repolarization pattern confined in inferolateral leads in patients with idiopathic ventricular fibrillation.

Objectives: The purpose of the present study was to investigate the prevalence and the prognostic significance of the early repolarization pattern in inferolateral leads in patients with Brugada syndrome.

Methods: Clinical, genetic, and electrophysiologic data from 290 individuals (223 males, mean age 48.3 +/- 14.2 years) with a spontaneous or drug-induced type 1 electrocardiogram (ECG) pattern of Brugada syndrome and structurally normal hearts were analyzed. Twelve-lead ECGs were evaluated for the presence of early repolarization pattern, which was defined as J-point elevation of at least 0.1 mV from baseline in at least two inferior or lateral leads. Follow-up data were obtained for all subjects.

Results: An early repolarization pattern manifested as notched or slurred J-point elevation mainly in lateral leads was observed in 35 subjects (12%). The prevalence of the early repolarization pattern was significantly higher in male subjects (P = .004). During a mean follow-up period of 44.9 +/- 27.5 months, 22 subjects (8%) displayed an arrhythmic event including sudden cardiac death. There were no significant differences regarding spontaneous ECG type of Brugada syndrome, symptoms, family history of sudden cardiac death, and positive genetic test between subjects with and without the early repolarization pattern. The presence of early repolarization pattern was not associated with arrhythmic events during follow-up (Hazard ratio [HR] 1.090; 95% confidence interval 0.349-3.403; P = .882).

Conclusion: The early repolarization pattern in inferolateral leads is not an uncommon finding in Brugada syndrome. In our population, the early repolarization features were not associated with a worse outcome in subjects with Brugada syndrome.