Medical Definition of Aortic stenosis
Aortic stenosis: Narrowing (stenosis) of the aortic valve, the valve between the left ventricle of the heart and the aorta. This narrowing impedes the delivery of blood to the body through the aorta and makes the heart work harder. The need for surgery depends on the degree of stenosis. A procedure called balloon valvuloplasty has been used in some cases of aortic stenosis.