Prognostic and clinical significance of newly acquired complete right bundle branch block in Japan Airline pilots.

Objective The purpose of this study was to evaluate the prognostic and clinical significance of newly acquired complete right bundle branch block (CRBBB) in airline pilots. Patients This study included pilots with acquired CRBBB, identified from a group of over 2, 700 Japan Airline pilots. When the pilots applied for employment, a past medical history, physical examination, electrocardiogram, and chest radiograph were obtained. The pilots with ECG abnormality including CRBBB were not included in the study because of hiring requirements. Results Thirty-six pilots with CRBBB were identified between 1983 and 2002. All pilots with CRBBB were evaluated for the presence of ischemic heart disease by treadmill exercise testing, echocardiogram and exercise thallium scintigraphy. Twelve individuals underwent coronary angiography. The mean age of pilots was 44.4 ±5.8 years. The mean observation period was 10.9±5.7 years. For each of the 36 study subjects, Holter electrocardiogram and echocardiogram were obtained every 6 months after the CRBBB was detected. Exercise stress testing was performed every year. Exercise thallium scintigraphy was performed every 2 years to detect ischemic heart disease. During the observation period, two pilots stopped flying temporarily because of frequent ventricular premature beats and one pilot stopped flying permanentaly because of atrial fibrillation. During the follow-up period, no cardiovascular events were observed in pilots with CRBBB who had no underlying ischemic heart disease. Conclusion Acquired CRBBB does not confer a poor prognosis, particularly in young men working as a pilot if there is no evidence of ischemia on exercise stress testing, echocardiography and exercise thallium scintigraphy.(Internal Medicine 42: 21-24, 2003)