Regression of infundibular hypertrophy after pulmonary valvulotomy without myocardial resection.

In the period 1965-1979, 26 patients underwent valvulotomy for congenital pulmonary valve stenosis without ventricular septal defect. Infundibular stenosis was additionally present in 14 of the patients, 12 children and 2 adults, but myocardial resection in the infundibular area was not performed. During the first postoperative year the right ventricular outflow tract underwent normalization in the 12 children and the right ventricular systolic pressure normalized in all 14 patients. No relationship could be demonstrated between the R wave in the precordial lead V1 and the systolic pressure in the right ventricle, the gradient to the pulmonary artery or the extent of subvalvular hypertrophy.