Primitive ventricle with acquired subpulmonary stenosis.

The course and natural history of two children aged 1 yr and 5 yr with primitive ventricle with outlet chamber and normally related great arteries are described. They initially presented as ventricular septal defect with increased pulmonary blood flow and subsequently developed 'cyanotic attacks', chronic cyanosis and diminished pulmonary flow by acquiring subpulmonary obstruction of the bulboventricular foramen. Both had successful surgical treatment utilizing their own normal pulmonary valves by connecting the right atrium to the right ventricular outflow, with a Dacron conduit in one, and in the other by detaching the pulmonary artery and valve from the rudimentary outflow chamber and anastomosing it directly to the right atrial appendage. Changing morphology and its effect on function are discussed.