Left Bundle Branch Block

Abstract

Coronary angiography, cine left ventriculography, and the cardiovascular hemodynamics of 24 patients with left bundle branch block were studied. Seven patients were found to have significant coronary artery disease, always severe. Five had cardiomyopathy and seven had valvular disease. Only those with coronary artery disease or cardiomyopathy had abnormal left ventricular contraction patterns. The onset of left ventricular contraction was delayed in the patients with left bundle branch block, but the period of isovolumic contraction was normal in those without severe underlying disease. Left axis deviation in addition to left bundle branch block did not imply more frequent coronary atherosclerosis.