“…H a l l i d i e -S m i t h el al. [14] found in 29 patients, 27 of whom were treated surgically, a systolic pressure gradient below the pulmonary valve or high in the body of the right ventricle of more than 20 mm Hg in 12 cases. Three of these patients had hypertrophy of the infundibulum requiring resection, in the remaining 9 patients, however, the pressure gradient disappeared after closure of the ventricular septal defect and repair of the aortic insufficiency, suggesting it might have been caused by prolapse of an aortic leaflet and/or sinus into the infundibulum.…”