Incidence of and risk factors for bundle branch block in adults older than 40 years.
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 on the incidence and correlation of BBB to clinical factors have produced conflicting results. However, the incidence of BBB was strongly related to age. This study aimed to describe the incidence of and risk factors for BBB in Korea.


METHODS
In this study, 14,540 adults (male 6,573/female 7,967) > or = 40 years old received screening tests for general health between April and December 2000. Participants answered questionnaires and underwent examinations, which included blood pressure, electrocardiogram (ECG), total cholesterol and fasting glucose. The data analysis was performed using SPSS 10.0 for windows.


RESULTS
The incidences of complete right bundle branch block (CRBBB) were 1.5 and 2.9% in people older than 40 and 65 years, respectively. Approximately 38.0% of individuals with CRBBB were older than 65 years. The incidence of CRBBB was higher in men than women at all age groups was highest in those aged 75-79 years. Males, advancing age (> or = 65 years), hypertension and diabetes mellitus (DM) were associated with an increased risk of CRBBB. The incidences of complete left bundle branch block (LBBB) and bifascicular bundle branch block (BBBB) were 0.1 and 0.08% and 0.3 and 0.2% in those older than 40 and 65 years, respectively. Approximately 71.4 and 58.3% of individuals with LBBB and BBBB, respectively, were older than 65 years. Advancing age and cardiac disease were associated with an increased risk of LBBB. Advancing age was associated with an increased risk of BBBB. The most potent risk factor for BBB in this study was advancing age.


CONCLUSIONS
The incidences of BBB were 1.7 and 3.4% in those older than 40 and 65 years respectively. Bundle branch block correlates strongly with age, and is common in the older ages groups. These findings support the theory that bundle branch block is a marker of slowly progressing degenerative diseases.
Department of Internal Medicine, Pusan National University College of Medicine, Busan, Korea.
Joon Hoon
JH
Jeong
June Hong
JH
Kim
Yong Hyun
YH
Park
Dong Cheul
DC
Han
Ki Won
KW
Hwang
Dong Won
DW
Lee
Jun Hyok
JH
Oh
Sung Gook
SG
Song
Jeong Su
JS
Kim
Kook Jin
KJ
Chun
Taek Jong
TJ
Hong
Yung Woo
YW
Shin
D000328:Adult; D000367:Age Factors; D002037:Bundle-Branch Block / Q000453:epidemiology*; D005260:Female; D006331:Heart Diseases / Q000150:complications / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007723:Korea / Q000453:epidemiology; D008297:Male; D012307:Risk Factors; D012737:Sex Factors