BACKGROUND: Brugada syndrome is the purported mechanism for sudden unexplained death syndrome, also known in the Philippine vernacular as bangungut. The Brugada electrocardiogram (ECG) pattern, which is the most useful marker of this condition, is found in 2% of Filipinos, most of whom are asymptomatic. There is a knowledge gap on the clinical outcome for individuals with asymptomatic Brugada pattern. Previous data show conflicting results.
OBJECTIVES: To determine the five-year cardiac event rate for individuals with the Brugada ECG pattern in the Life Course Study in Cardiovascular Disease Epidemiology (LIFECARE) cohort.
METHODOLOGY: This is a substudy of LIFECARE, a community-based cohort among apparently healthy individuals 20 to 50 years of age, initially conducted in 2009 to 2010.In our previous study, ECG tracings of 3,072 participants were reviewed, and 163 (5.3%) were identified to have any Brugada pattern. Six of the 163 were nonsurvivors. In this present study, a cardiac event questionnaire was administered to the survivors and a sudden unexplained death questionnaire was administered to the nearest of kin of the six nonsurvivors approximately five years after ECG identification. The outcome determined is the occurrence of any cardiac event (i.e., sudden death, syncope, presyncope, seizure, and nonfatal cardiac arrest).
RESULTS: Of the 163 patients with any Brugada ECG pattern at baseline, 12 (7.4%) had a cardiac event. Eleven of these 12 were asymptomatic on initial ECG diagnosis; five had sudden unexplained deaths; and seven had syncope, presyncope, or nonfatal cardiac arrest. Six of the seven were asymptomatic prior to the ECG diagnosis of a Brugada pattern. All victims of sudden death, as well as majority of those with cardiac events, had a type 2 pattern. Of the 163 participants, seven had a family history of sudden death.
CONCLUSION: Cardiac events, including sudden unexplained death, occurred commonly among initially asymptomatic Filipinos with the Brugada type 2 ECG pattern. This gives significant implications on our approach to apparently healthy individuals with an incidental Brugada pattern on ECG.