Rapid evolution from "normal" left ventricular outflow tract to fatal subaortic stenosis in infancy.

Abstract
Serial clinical, echocardiographic, hemodynamic and angiocardiographic data support the conclusion that over 4 mo. severe discrete subaortic stenosis evolved from a previously angiocardiographically normal left ventricular outflow tract in a human infant who had a successful repair of thoracic aortic coarctation. A myocardial factor may play an important role in the change in form and function of some congenitally malformed hearts.