Lewis (1925) stated that delay in the passage of the impulse down a bundle branch could alter materially the form of the electrocardiogram. Wilson (1940) defined incomplete bundle branch block as due to a conduction defect that merely retards the passage of the impulse through one of the main bundle branches, and stated that it gives rise to electrocardiograms which are " transitional, both as ...

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. ...