FAA Office of Aerospace Medicine
Civil Aerospace Medical Institute
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AVIATION MEDICINE REPORTS

Report No: DOT/FAA/AM-90/7

Title and Subtitle: Right Bundle Branch Block as a Risk Factor for Subsequent Cardiac Events

Report Date: August 1990

Authors: Hudson, L.S., Booze, C.F. and Davis, A.W.

Abstract: The identification of risk factors for adverse cardiac events is valuable to the certification of airmen. This study examines the importance of right bundle branch block (RBBB) as a risk factor for myocardial infarction (MI), atherosclerotic heart disease (ASHD) and coronary heart disease (CHD). Using a non-concurrent prospective design, 433 Class I airmen between the ages of 35 and 60 years who had an RBBB on their electrocardiogram (ECG) in 1970 were matched to 338 control Class I airmen who had no abnormalities on their 1970 ECG. Using the longitudinal database maintained by the Federal Aviation Administration (FAA), the medical records of these airmen were screened for MI, ASHD, and CHD through the end of 1985. Questionnaires were sent to airmen with incomplete data on the computerized database. The first occurrence of any of these outcomes was considered an adverse cardiac event. In the case group, 24 cardiac events occurred (3.93/1,000 person-years) compared with 9 events in the control group (1.87/ 1,000 person-years). The relative risk was 2.012 with 957O confidence intervals of .994 to 4.484. The ChiSquare for independence was 3.85 1 df, p0.05. The findings suggest an increased risk of adverse cardiac events but are of borderline statistical significance.

Key Words: Aeromedical certification, Right bundle branch block, Myocardial infarction, Coronary heart disease

No. of Pages: 8