Predictive value of notched P wave for life-threatening arrhythmias in patients with Brugada syndrome: Insights from a multicenter prospective study

BACKGROUND Risk stratification for ventricular fibrillation (VF) in Brugada syndrome (BrS) remains a major clinical challenge. Atrial fibrillation is relatively common in BrS, suggesting that atrial conduction abnormalities may be related to arrhythmogenesis. A notched P wave on the surface electrocardiogram (ECG) reflects atrial conduction delay, but its prognostic significance for VF in BrS has not been fully established. OBJECTIVE To evaluate the association between notched P waves and life-threatening arrhythmic events in patients with BrS. METHODS We analyzed 510 patients with BrS (mean age, 51 ± 14 years; 95% men) enrolled in a prospective multicenter registry across 61 hospitals in Japan. Clinical and ECG parameters at enrollment were assessed, and patients were followed for cardiac events (VF, sustained ventricular tachycardia, or sudden cardiac death). RESULTS During a mean follow-up of 107 ± 62 months, 58 patients (11%) experienced cardiac events. Notched P waves were present in 52 patients (10%). Patients with notched P waves had a significantly higher incidence of cardiac events compared with those without (27% vs. 10%, p < 0.001). Kaplan-Meier analysis demonstrated lower event-free survival in patients with notched P waves (p < 0.001). In multivariable Cox regression, a notched P wave remained an independent predictor of cardiac events (hazard ratio: 2.63; 95% CI: 1.35-4.78; p = 0.006), along with a history of VF. CONCLUSIONS A notched P wave on a standard 12-lead ECG independently predicts life-threatening arrhythmias in BrS and may improve risk stratification by complementing conventional predictors.