The prevalence, incidence and prognostic value of the Brugada-type electrocardiogram - A population-based study of four decades

OBJECTIVES We sought to demonstrate the prevalence, incidence and prognosti c value of the Brugada-type electrocardiogram (ECG) in a general population . BACKGROUND The Brugada syndrome is characterized by evidence of right bundl e branch block and ST segment elevation in the right precordial leads, as w ell as sudden death caused by ventricular fibrillation. However, the natura l history of the Brugada-type ECG remains unclear. METHODS We investigated 4,788 subjects (1,956 men and 2,832 women) who were < 50 years old in 1958 and had undergone biennial health examinations, inc luding electrocardiography, through 1999. The Brugada-type ECG was defined as a terminal r ' wave in lead V-1 and ST segment elevation greater than or equal to0.1 mV in leads V-1 and V-2. Unexpected death was defined as sudde n death or unexplained accidental death. RESULTS There were a total of 32 Brugada-type ECG cases; the prevalence and incidence were 146.2 in 100,000 persons and 14.2 persons per 100,000 perso n-years, respectively. The incidence was nine times higher among men than w omen, and the average age at presentation was 45 +/- 10.5 years. The Brugad a-type ECG appeared intermittently in most cases and was found in 26% of su bjects who died unexpectedly. Cox survival analysis revealed that mortality from unexpected death was significantly higher in subjects with a Brugada- type ECG than in control subjects (p < 0.01). Unexpected deaths were more f requent among subjects with the Brugada-type ECG who had a history of synco pe (p < 0.05). CONCLUSIONS The Brugada-type ECG is not a very rare condition in the adult Japanese population. Subjects with a Brugada-type ECG have an increased ris k of unexpected death. (C) 2001 by the American College of Cardiology.