Further Observations on the Aberrant Electrocardiogram Associated With Sclerosis of the Atrioventricular Bundle Branches and Their Terminal Arborizations

In a previous paper¹we reported the clinical observations on twenty-two cases in which aberrant electrocardiograms were obtained, attributing the abnormal type of the ventricular complex to a temporary or permanent defect in conductivity of the branches of the atrioventricular bundle. As characterizing the essential difference between the aberrant electrocardiogram and the normal type, we emphasized the prolongation of the P-R interval beyond 0.20 second; the increase in the duration of the QRS interval beyond 0.10 second, particularly when it constitutes more than one third of the duration of the entire complex; the deflection of the T-wave in a direction opposite to that of the prominent initial deflections, with frequent conspicuous exaggeration of its amplitude; the relatively increased amplitude of the initial deflections of the ventricular complex in an opposite direction in Leads I and III, often markedly notched, and finally, the tendency of these deflections to assume a diphasic