Incidence of and risk factors for bundle branch block in screening test for 40 years and older adults

Jeong, Joon Hoon

Abstract

BACKGROUND: In the general population, the incidence of bundle branch block (BBB) is relatively low, and its effects on long-term prognosis have not been established. Previous studies of incidence and correlation to clinical factors have produced conflicting results. But, the incidence of BBB was strongly related to age. This study aimed to describe the incidence of and risk factors for BBB in Korean.
METHODS
In this study, 14,540 adults (M/F=6,573/7,967) >or=40 years old were received screening test for general health between April 2000 and December 2000. Participants answered questionnaires and underwent examinations that included blood pressure, electrocardiogram (ECG), total cholesterol, and fasting glucose. Data analysis was done by database statistics (dBSTAT) for windows program.
RESULTS
The incidence of complete right bundle branch block (CRBBB) was 1.5% in people older than 40 years and 2.9% in those older than 65 years. Approximately 38.0% of individuals with CRBBB were older than 65 years. The incidence of CRBBB is higher at all age group in men than in women. Also, the incidence of CRBBB is most highest in aged 75~79 years. Male, advancing age ( >or=65 years), hypertension, and diabetes mellitus (DM) were associated with an increased risk of CRBBB. The incidence of complete left bundle branch block (LBBB) and bifascicular bundle branch block (BBBB) were 0.1%, 0.08% in people older than 40 years and 0.3%, 0.2% in those older than 65 years, respectively. Approximately 71.4%, 58.3% of individuals with LBBB and BBBB were older than 65 years, respectively. Advancing age ( >or=65 years) and myocardial infarction (MI) were associated with an increased risk of LBBB and BBBB. The most potent risk factor of BBB was advancing age in this study.
CONCLUSION
The incidence of BBB was 1.7% in those older than 40 years and 3.4% in those older than 65 years. Approximately 89.3% of individuals with BBB were CRBBB. The incidence of CRBBB is 1.5-fold in men than in women. The most potent risk factor of BBB was advancing age.