Tetralogy of Fallot with discrete fibrous subaortic stenosis.

This is the first reported case of discrete fibrous subaortic stenosis in tetralogy of Fallot. Transaortic excision of the subaortic membrane was readily accomplished. To detect this and other forms of left ventricular outflow-tract obstruction in tetralogy of Fallot before surgery, routine selective left ventriculography is advocated.