Inexcitable right ventricle and bilateral bundle branch block in Uhl's disease.

Abstract

A 29 yr old female with Uhl''s anomaly developed complete atrioventricular (A-V) block. His bundle studies revealed block distal to the His bundle recording site with narrow QRS complexes. Right ventricular capture could not be obtained, and despite successful left ventricular epicardial pacing, the patient died. Autopsy revealed absence of myocardium in most areas of the right ventricle and the right side of the ventricular septum with a normal tricuspid valve. Conduction system examination revealed total destruction of both bundle branches. This is the 1st case where bilateral bundle branch block was present in Uhl''s anomaly. Narrow QRS complexes probably reflected the absence of right ventricular forces.