[Fixed subvalvular aortic stenosis. Monodimensional echocardiographic findings].

19 patients affected by discrete subvalvular aortic stenosis were studied by M-mode echocardiography. The diagnosis was confirmed by cardiac catheterism and angiocardiography and by anatomic evidence in operative room. The most frequent echocardiographic pattern was the abnormal protosystolic movement of aortic valve leaflets, that was found in all the patients. A discrete linear echo in the outflow tract of the left ventricle was observed in almost half of the cases. In 40% of the cases the left ventricular outflow tract was narrowed. The relations between these echocardiographic patterns and the anatomical kinds of discrete subaortic stenosis are discussed. No correlations were found between echocardiographic patterns and severity of the subaortic stenosis.