The Utility of Notched P-Wave on the Occurrence of Ventricular Fibrillation in Patients With Brugada Syndrome.

Background: Risk stratification for ventricular fibrillation (VF) in patients with Brugada syndrome (BrS) remains a significant clinical challenge. Atrial fibrillation (AF) is relatively common in BrS, suggesting arrhythmogenic abnormalities in both the atria and ventricles. The purpose of this study was to investigate the relationship between P-waveforms and VF occurrence in patients with BrS.

Method: Eighty-two patients with BrS were retrospectively evaluated and classified into two groups based on the occurrence of VF during the overall clinical course: VF occurrence (n = 34) and VF nonoccurrence (n = 48). The relationship between VF occurrence and parameters on 12-lead electrocardiogram (ECG) at the initial visit, prior to any drug administration, was analyzed.

Results: During a median follow-up of 75.0 months, VF occurred in 23 patients, including 19 recurrent and four new cases. Multivariable logistic regression identified notched P-wave as an independent risk factor for VF occurrence in all models (odds ratios 6.45-8.45; all p < 0.01). Depending on the model, symptomatic BrS, early repolarization pattern, and fragmented QRS were also independently associated with VF. Kaplan-Meier analysis showed a significantly lower incidence of VF in patients with BrS who have neither a history of VF nor a notched P-wave (p < 0.0001).

Conclusions: Notched P-wave on 12-lead ECG is a significant risk factor for the occurrence of VF in patients with BrS. Notched P-wave in patients with BrS may indicate the presence of an underlying arrhythmogenic substrate predisposing to VF.