title: Clinical significance of exercise-induced bundle branch block.
abstract: To evaluate the diagnostic significance and long-term follow-up data of patients with exercise-induced bundle branch block (BBB), 10,176 consecutive patients' exercise test data were reviewed and 50 patients found to have exercise-induced BBB. Clinical, exercise test and arteriographic data were analyzed along with follow-up data during a mean of 43 months. Of the 50 patients, 37 had exercise-induced left BBB and 13 had exercise-induced right BBB. Significant coronary artery disease (CAD) was diagnosed in 26 of 37 patients (70%) with exercise-induced left BBB and in all 13 patients (100%) with exercise-induced right BBB. In patients who underwent coronary arteriography, data demonstrated a high prevalence of proximal left anterior descending disease (17 of 20, 85%). Follow-up data revealed that exercise-induced BBB was associated with a 36% (18 of 50) incidence of coronary events, including 16 patients who underwent coronary artery bypass grafting and 2 hospitalized for congestive heart failure. Results indicated that exercise-induced BBB was infrequent and occurred primarily in association with CAD, had a high prevalence of proximal left anterior CAD, infrequently had similar onset and offset heart rates, was reproducible and associated with a greater incidence of coronary artery bypass grafting than had been previously reported, although the incidence of cardiac events was similar to those investigations.
authors.affiliation: Division of Cardiology, Creighton University Medical School, Omaha, Nebraska.
authors.forename: M A
authors.initials: MA
authors.lastname: Williams
authors.forename: D J
authors.initials: DJ
authors.lastname: Esterbrooks
authors.forename: C K
authors.initials: CK
authors.lastname: Nair
authors.forename: M M
authors.initials: MM
authors.lastname: Sailors
authors.forename: M H
authors.initials: MH
authors.lastname: Sketch
mesh_terms: D000328:Adult; D000368:Aged; D002037:Bundle-Branch Block / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D017023:Coronary Angiography; D003327:Coronary Disease / Q000150:complications / Q000000981:diagnostic imaging; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D005082:Physical Exertion