An unusual electrocardiographic pattern of left ventricular endocardial pacing

Pacemaker stimulation of the left ventricle is expected to yield a pattern of complete right bundle branch block, however, unusual patterns have been reported. The present report is a case of an unusual electrocardiographic pattern from left ventricular endocardial pacing in a patient with an atrial septal defect and acute myocarditis complicated by complete degree atrioventricular block.