Prognosis of subjects with Brugada-type electrocardiogram in a population of middle-aged Japanese diagnosed during a health examination.

There is controversy about the clinical significance of an incidental finding of a Brugada-type electrocardiogram (ECG) pattern. To assess the prognosis of subjects with a diagnosis of a Brugada-type ECG pattern during a health examination, 13,904 subjects (mean age 58 +/- 10 years) who had the annual health examination including an ECG offered to adult citizens of Moriguchi City, Osaka, Japan, in 1997 were studied. A Brugada-type ECG pattern was found in 98 subjects, and 37 subjects had type 1. During a mean follow-up of 7.8 +/- 1.6 years, there were 4 deaths (4.1%) and 1 cardiovascular death (1.0%) in subjects with a Brugada-type ECG pattern, whereas there were 612 deaths (4.4%) and 142 cardiovascular deaths (1.0%) in those without. One cardiovascular death in a subject with a Brugada-type ECG pattern was sudden death. Unadjusted proportional hazards regression analyses showed that Brugada-type ECG pattern was not associated with either all-cause (hazard ratio [HR] 0.90, 95% confidence interval [CI] 0.34 to 2.41) or cardiovascular mortality (HR 0.97, 95% CI 0.14 to 6.93). After adjustment for cardiovascular risk factors, Brugada-type ECG pattern had no association with either all-cause (HR 0.77, 95% CI 0.29 to 2.07) or cardiovascular mortality (HR 1.01, 95% CI 0.14 to 7.31). In conclusion, Brugada-type ECG patterns diagnosed during a health examination in a middle-aged population had a low risk of sudden death and were not associated with increased risk of either cardiovascular or all-cause mortality.