Determinants of sudden cardiac death in individuals with the electrocardiographic pattern of Brugada syndrome and no previous cardiac arrest

Background - Patients with Brugada syndrome who were resuscitated from an episode of ventricular fibrillation are at high risk for recurrent sudden death. There is general agreement about the therapeutic strategy for these patients. Conversely, the prognosis and approach in patients with a diagnostic ECG but without a previous history of sudden cardiac death is controversial. We analyzed a large cohort of patients with Brugada syndrome without previous cardiac arrest to understand the determinants of prognosis. Methods and Results - A total of 547 patients with an ECG diagnostic of Brugada syndrome and no previous cardiac arrest were studied. The mean age was 41 +/- 15 years, and 408 were male. The diagnostic ECG was present spontaneously in 391 patients. In the remaining 156 individuals, the abnormal ECG was noted only after the administration of an antiarrhythmic drug. One hundred twenty-four patients had suffered from at least 1 episode of syncope. During programmed ventricular stimulation, a sustained ventricular arrhythmia was induced in 163 of 408 patients. During a mean follow-up of 24 +/- 32 months, 45 patients (8%) suffered sudden death or documented ventricular fibrillation. Multivariate analysis identified the inducibility of a sustained ventricular arrhythmia ( P < 0.0001) and a history of syncope ( P < 0.01) as predictors of events. Logistic regression analysis showed that a patient with a spontaneously abnormal ECG, a previous history of syncope, and inducible sustained ventricular arrhythmias had a probability of 27.2% of suffering an event during follow-up. Conclusions - Individuals with Brugada syndrome and no previous cardiac arrest have a high risk of sudden death. Inducibility of ventricular arrhythmias and a previous history of syncope are markers of a poor prognosis.