1 Departments of Pediatrics, Case Western Reserve School of Medicine, Cleveland, Ohio, and The Milton S. Hershey Medical Center, Hershey, Pennsylvania, and the Department of Internal Medicine, Mt. Sinai Hospital of Cleveland, Cleveland, Ohio
Ectopic foci associated with aberrant intraventicular conduction (AIVC) may either be ventricular foci or supraventricular foci. The electrocardiogram may not help in this differentiation. Knowledge of the site of origin is essential to determine appropriate therapy for patients who develop sustained tachycardias and may be of prognostic value in those who have frequent premature contractions. To determine the site of the ectopic focus, His bundle electrograms were performed in seven children whose conventional ECGs showed arrhythmias with frequent premature ectopic beats and runs of bigeminy with AIVC. In two patients the focus was in the supraventricular area while the other five had a ventricular focus. Incomplete right bundle branch block was noted in one patient with a supraventricular focus but complete bundle branch block occurred in both patients with both ventricular and supraventricular foci.
Submitted on May 16, 1975