Underdeveloped right ventricle and pulmonary stenosis ∗

Abstract

There is a poorly documented cyanotic congenital malformation in which moderate underdevelopment of the right ventricle and hypoplasia of the tricuspid valve ring occur in association with pulmonary stenosis. Four patients with this malformation had characteristic signs which allow the diagnosis to be made on clinical grounds. Although they presented some findings consistent with severe pulmonary stenosis, in no case was there more than a slight right ventricular lift; the electrocardiogram showed little or no evidence of right ventricular hypertrophy; and in 3 cases splitting of the second heart sound behaved paradoxically with respiration. Cardiac catheterization data before and after correction of the malformation indicate that the right-to-left shunt at atrial level is caused by the abnormal filling resistance of the small right ventricle. The condition can be effectively treated by pulmonary valvotomy with cardiopulmonary bypass, excision of trabeculation in the right ventricle, and closure of the interatrial communication.