[Isolation right ventricular hypoplasia: report of two cases].

Two cases of the hypoplastic right ventricle are reported. Patient 1: A five-year-old boy underwent cardiac catheterization 13 days after birth which revealed that the end-diastolic volume in the right ventricle was 2 ml. It was 20 ml at the age of two years and 40 ml at five years. Thus, the right ventricular hypoplasia lessened with increasing age. Neither pulmonary nor tricuspid valvular malformation was present. Patient 2: A four-month-old boy received two-dimensional echocardiographic examination at the age of two days which revealed: 1) a small right ventricle in the apical four-chamber view, 2) a half-moon-shaped right ventricle in the subxyphoid short-axis view at the level of the great arteries, and 3) normal positioning of the septal leaflet of the tricuspid valve. Pulsed Doppler echocardiography revealed normal blood flow patterns, immediately above the pulmonary valve and below the tricuspid valve. Cardiac catheterization at the age of three months indicated isolated right ventricular hypoplasia, a diverticulum of the right ventricle, and dilated cardiomyopathy. The patient died of congestive heart failure at the age of four months. Autopsy confirmed the above diagnoses.