Four-leaflet pulmonary valve in the setting of hypoplastic left heart syndrome.

The association of hypoplastic left heart syndrome with pulmonary valvular abnormalities such as dysplasia, stenosis, or insufficiency is rare and not well defined in the literature. We report a rare case of hypoplastic left heart syndrome with a thickened four-leaflet, four-sinus pulmonary valve. After stage I palliation, this neo-aortic valve developed clinically significant insufficiency in the setting of increased pulmonary blood flow.