Risk stratification of ventricular fibrillation in patients with symptomatic Brugada syndrome using pharmacological tests

BACKGROUND: Brugada syndrome (BrS), which is characterized by J-point elevation in right precordial leads of a 12-lead electrocardiogram, is associated with the occurrence of ventricular fibrillation (VF). However, risk stratification of VF in patients with BrS remains challenging. OBJECTIVE: The aim of this study was to identify a risk predictor of VF in patients with BrS using pharmacological tests. METHODS: Twenty-one consecutive patients with BrS and a history of documented spontaneous VF (n = 16) or syncope presumed to be caused by lethal ventricular arrhythmia (n = 5) were enrolled. J-wave changes in response to intravenous verapamil, propranolol, and pilsicainide were separately assessed. RESULTS: During the median follow-up period of 86.0 months, 8 patients had VF recurrence (recurrence group) and 13 patients did not have VF recurrence (non-recurrence group). Intravenous propranolol injection induced significant J-wave augmentation (i.e., increase in amplitude >0.1 mV) in the inferior and/or lateral leads in the recurrence group compared to the non-recurrence group (p = .048 and p = .015, respectively). Kaplan-Meier analysis revealed that VF recurrence is significantly higher in patients with BrS and J-wave augmentation due to intravenous propranolol than in patients without J-wave augmentation (p = .014). CONCLUSION: The study results show that propranolol-induced J-wave augmentation is involved in the risk of VF in patients with BrS. The results suggest that early repolarization patterns in response to pharmacological tests may be useful for risk stratification of VF in patients with symptomatic BrS.