Prevalence and Clinical Impact of Early Repolarization Pattern and QRS-Fragmentation in High-Risk Patients With Brugada Syndrome

BACKGROUND: The phenotypic heterogeneity of Brugada syndrome (BrS) can lead some patients to show an additional inferolateral early repolarization pattern (ERP), or fragmented QRS (f-QRS). The aim of the study was to investigate the prevalence and clinical impact of f-QRS, ERP or combined f-QRS/ERP in high-risk patients with BrS.Methods and Results:Patients with spontaneous or drug-induced BrS and an indication to receive an implantable cardioverter-defibrillator (ICD) were considered eligible for this study. From 1992 to 2012, a total of 176 consecutive patients with BrS underwent ICD implantation. Among them, 48 subjects (27.3%) presented with additional depolarization and/or repolarization abnormalities. f-QRS was found in 29 (16.5%), ERP in 15 (8.5%), and combined f-QRS/ERP in 4 patients (2.3%). After a mean follow-up of 95.2±51.9 months, spontaneous sustained ventricular arrhythmias were documented in 8 patients (16.7%). No significant difference was found in the rate of appropriate shocks between patients presenting with f-QRS or ERP and those without abnormalities. Patients with both f-QRS and ERP had a significantly higher rate of appropriate shocks (HR: 4.1; 95% CI: 1.1-19.7; P=0.04).

CONCLUSIONS: Fragmented QRS and ERP are common ECG findings in high-risk BrS patients, occurring in up to 27% of cases. When combined, f-QRS and ERP confer a higher risk of appropriate ICD interventions during a very long-term follow-up.