Prognostic significance of early repolarization in inferolateral leads in Brugada patients with documented ventricular fibrillation: A novel risk factor for Brugada syndrome with ventricular fibrillation

Background Little is known about the clinical and prognostic impact of early repolarization (ER) on patients with Brugada syndrome (BrS), especially those with documented ventricular fibrillation (VF). Objective To investigate the prevalence and prognostic significance of ER in inferolateral leads in patients with BrS and documented VF. Methods We investigated 10 different 12-lead electrocardiograms (ECGs) recorded on different days to identify the presence of ER, which was defined as J-point elevation ≥0.1 mV in inferior (II, III, aVF) or lateral leads (I, aVL, V₄-V₆), in 49 individuals (46 men; age 46 ± 13 years) with a type 1 ECG of BrS and previous history of VF. Results ER was observed persistently (in all ECGs) in 15 patients (31%; P group), intermittently (in at least one but not in all ECGs) in 16 patients (33%; I group), and not observed in 18 patients (37%; N group), yielding an overall ER incidence of 63% (31/49). During the follow-up period (7.7 years), recurrence of VF was documented in all 15 patients (100%) in the P group, and less in 12 patients (75%) in the I group and in 8 patients (44%) in the N group. The P group showed a worse prognosis than N group (P =.0001) by Kaplan-Meier analysis. Either persistent or intermittent ER in an inferolateral lead was an independent predictor of fatal arrhythmic events (hazard ratio 4.88, 95% confidence interval 2.02-12.7, P =.0004; and hazard ratio 2.50, 95% confidence interval 1.03-6.43, P =.043, respectively). Conclusion The prevalence of ER in inferolateral leads was high and an especially persistent form of ER was associated with a worse outcome in BrS patients with documented VF.