Predictors of atrial tachyarrhythmias in subjects with type 1 ECG pattern of Brugada syndrome.

BACKGROUND: Previous studies have demonstrated a high incidence of atrial tachyarrhythmias (ATs) in patients with Brugada syndrome (BS). The present study aimed to investigate whether various 12-lead electrocardiogram (ECG) and electrophysiological parameters may help to differentiate subjects with a high probability to develop ATs.

METHODS AND RESULTS: The clinical records of 38 individuals (31 males, age 44.4 +/- 13.9) with spontaneous (n = 15) or ajmaline-induced (n = 23) type 1 ECG pattern of BS were analyzed. During a mean follow-up period of 4.6 +/- 2.2 years, nine subjects suffered ATs (24%). Six subjects displayed paroxysmal atrial fibrillation and three typical atrial flutter. Among the studied 12-lead ECG parameters, subjects with ATs exhibited increased values of P-wave duration in lead II, P-wave dispersion, PR interval in leads II, QRS duration in leads II and V(2), Tpeak-end interval in lead II, and Tpeak-end dispersion of the 12 leads in relation to those without ATs (P < 0.05). Among the assessed electrophysiological parameters, atrial-His (AH) and His-ventricular (HV) intervals were significantly prolonged in subjects with ATs (P < 0.05). Multiple Cox proportional hazards analysis revealed that P-wave duration in lead II, P-wave dispersion, Tpeak-end in lead II, Tpeak-end dispersion of the 12 leads, as well as AH and HV intervals are independent predictors of ATs in subjects with BS (P < 0.05). Cut-off point analysis showed that an HV interval>or=56 ms displayed the highest predictive ability (P < 0.01).

CONCLUSION: Our findings demonstrate that simple 12-lead ECG and electrophysiological parameters may easily be applied to identify high-risk subjects with BS ECG phenotype to develop ATs.