Aneurysmal dilatation of the right ventricular outflow tract in infancy: severe form of Uhl's anomaly?

A previously unreported cardiovascular malformation is presented consisting of aneurysmal dilatation of the right ventricular outflow tract associated with a cardiomyopathy, a possible variant of Uhl's anomaly. The patient presented at 8 days of age with mild cyanosis and congestive failure. Cardiac catheterization revealed severe cardiomegaly associated with very poor pump function of both right and left ventricles. The present case is unique in showing 1) severe aneurysmal dilatation of the right ventricular outflow tract. 2) only partially absent right ventricular musculature documented before death by the pressure tracing and cineangiocardiograms, and 3) the first quantitation of both right and left ventricular size and function in this syndrome. A review of previous cases of Uhl's anomaly indicates that this case may represent a variant of that condition and that intrauterine myocarditis or myocardial infarct should be considered in regard to etiology.