[Exercise-induced left bundle branch block in treadmill exercise test: clinical significance and prognosis].
Exercise induced left bundle branch block (LBBB) is poorly understood. We investigated its clinical characteristics and prognosis. The records of 3,459 consecutive patients who underwent treadmill exercise testing were reviewed. Exercise induced LBBB was identified in 6 patients (0.17%). Three out of six patients had underlying cardiac disease; two had coronary artery disease and one dilated cardiomyopathy. Three out of five had redistribution on Tl-201 myocardial scintigraphy. In one of these three patients, however, coronary angiography demonstrated no significant narrowings. Tl-201 myocardial scintigraphy in patients with exercise induced LBBB may be undetermined for coronary artery disease. During follow-up, one of six patients had depressed left ventricular function and was diagnosed as having dilated cardiomyopathy. It is thus obvious that exercise induced LBBB without a specific underlying heart disease should be followed up carefully.
Aoki
T
T
Division of Cardiology, Yamada Red Cross Hospital.
Nishikawa
H
H
Motoyasu
M
M
Shimizu
Y
Y
Ono
N
N
Unno
M
M
Kakuta
Y
Y
Konishi
T
T
Nakano
T
T
D000368:Aged; D002037:Bundle-Branch Block / Q000175:diagnosis* / Q000209:etiology; D002312:Cardiomyopathy, Hypertrophic / Q000150:complications; D003324:Coronary Artery Disease / Q000150:complications; D005080:Exercise Test; D005260:Female; D006801:Humans; D008875:Middle Aged; D011379:Prognosis; D015899:Tomography, Emission-Computed, Single-Photon