**3.7 Aortic stenosis**

Aortic stenosis (AS) may be to congenital or acquired, and the congenital form could be above (supra), below (subvalvular) or at the valve level. A supravalvular is a rare form of long and tubular narrowing is associated with, (William's Syndrome) hypercalcemia, mental retardation, and peripheral pulmonic stenosis. Subvalvular stenosis may be caused by the septum extending into the outflow tract, a cylindrical constriction of the outflow tract or, in hypertrophic cardiomyopathy the obstruction caused by the anterior movement of the mitral valve leaflets. In some patients, this is present only at diminished ventricular (LV) volumes recreated in the echocardiography laboratory by Valsalva cause aortic regurgitation [32].
