Left Heart Anomalies: Aortic Stenosis, Hypoplastic Left Heart Syndrome, Shone's Complex

Obstructions of the left ventricular outflow can be classified on the basis of the site of the obstruction into valvular, subvalvular, and supravalvular stenosis [1,2]. The single variant consistently detected in the fetus is the valvular one (about two-thirds of cases) [2]; in this case, the valvular ring is often of normal size, and the stenosis is the result of the valvular dysplasia.