Left bundle branch block and coronary artery disease.

This study tries the concept that left bundle-branch block (LBBB) connotes coronary artery disease (CAD). The findings indicate that prior studies both supporting of and in contradiction to the premise of a positive correlation have been biased by pre-selection of the patients reviewed. The data indicate, therefore, that LBBB is related to multiple entities. The major categories are CAD and/or hypertension myocardiopathy and aortic valvular disease. In addition, LBBB may develop during the acute phase of myocardial infarction. Its existence as a wholly benign entity has been documented as well. Further, this study adds still another group with LBBB. Six of the nine LBBB patients were female. Five of these, in spite of typical anginal histories, had no arteriographically demonstrable CAD. The absence of disease was surprising and the incidence of women with LBBB was greater than anticipated, thus providing some basis for suggesting that these women may be representative of still another group with LBBB. Further, this study supports the findings of Lewis et al by confirming an association between LBBB and a statistically shorter LCA mainstem (p less than 0.001).