Clinical Significance of J Wave in Patients with Brugada Syndrome

Background: Clinical significance of J wave, one of early repolarization characteristics, in Brugada syndrome, remains to be elucidated. In this study, we examined the clinical significance of J wave in clinical symptoms and VF inducibility determined by electrophysiological study in patients with Brugada syndrome. Method and Results: We performed VF induction test in 30 consecutive patients who were suspected as Brugada syndrome with type 1 ECG appearance (male/female, 29/1; averaged age, 48±11[SD] years old). Among the 30 patients, 24 were diagnosed as Brugada syndrome. In these 24 patients, 14 were symptomatic and the remaining 10 were asymptomatic. J wave was observed in 7 out of the 24 patients with Brugada syndrome (29% of Brugada syndrome). In contrast, none of the 6 patients with negative VF induction test had J wave. Moreover, among the 24 patients of Brugada syndrome, J wave was observed in only 1 case out of the asymptomatic 10 cases (10% of asymptomatic Brugada syndrome), whereas it was observed in 6 out of the 14 symptomatic patients (42% of symptomatic Brugada syndrome). Conclusions: These results indicate that J wave could have some clinical implications for both clinical symptoms and VF inducibility in patients with Brugada syndrome, suggesting that J wave reflects the arrhythmogenic substrates and the clinical phenotype in Brugada syndrome.