Electrocardiographic findings in patients with complete atrioventricular block.

Abstract

The review and analysis of the ecg tracings of 57 patients with complete A-V [atrio-ventricular] block studied over a five-year period indicate that 45 patients (79%) had a bilateral bundle-branch block, which includes 3 stages. The 1st is characterized by the presence of a bundle-branch block; in the 2nd the bundle-branch block is complicated by a 1st- and/or 2nd-degree A-V block; and in the 3rd stage both bundle-branches are blocked and a subsidiary ventricular pacemaker (with aberrant ventricular complexes) drives the ventricles. Five patients (9%) had an acquired A-V block situated above the bifurcation. In only 5 patients was myocardial infarction considered to be the cause of the A-V block. In the 7 patients (12%) with congenital A-V block, the interruption of the conduction system was situated above the bifurcation. Clinically, these patients were quite distinct from the other groups.