Clinical Differences in Japanese Patients Between Brugada Syndrome and Arrhythmogenic Right Ventricular Cardiomyopathy With Long-Term Follow-Up.

Some Brugada syndrome (BrS) patients have been suspected of being in the initial state of arrhythmogenic right ventricular cardiomyopathy (ARVC). This study aimed to clarify the electrocardiographic (ECG) and clinical differences between BrS and ARVC in long-term follow-up (mean 11.9 ± 6.3 years). A total of 50 BrS and 65 ARVC patients with fatal ventricular tachyarrhythmia (VTA) were evaluated according to the revised Task Force Criteria for ARVC. Based on the current diagnostic criteria concerning electrocardiographic, repolarization abnormality was positive in 2.0% and 2.6% of BrS patients at baseline and follow-up, and depolarization abnormality was positive in 6.0% and 12.8% of BrS patients at baseline and follow-up, respectively. At baseline, none of the BrS patients were definitively diagnosed with ARVC. Considering patients' lives since birth, Kaplan-Meier analysis revealed that age at first VTA attack showed the same tendency between the groups (BrS: mean 42.2 ± 12.5 years old vs ARVC: mean 44.8 ± 13.7 years old, log-rank p = 0.123). Moreover, the incidence of VTA recurrence was similar between the groups during follow-up (log-rank p = 0.906). Incidence of sustained monomorphic ventricular tachycardia was significantly higher in ARVC than in BrS whereas the opposite was true for ventricular fibrillation (log-rank p <0.001 and p <0.001, respectively). None of the diagnoses of BrS patients were changed to ARVC during follow-up. During long-term follow-up, although age at first VTA attack and VTA recurrence were similar, BrS consistently exhibited features that differed from those of ARVC.