The aortic valve separates the left ventricle (the main pumping chamber of the heart) and the aorta, the main and largest artery in the body. The aortic valve normally consists of three leaflets.
When the heart contracts, the leaflets opens and the heart pushes blood through the valve to the aorta and then to the rest of the body. When the heart relaxes, the aortic valve closes and prevents the blood from leaking (regurgitating) back into the ventricle.
The valve may become narrowed (stenotic) resulting in the restriction blood flow. Some patients develop symptoms as a result of the abnormalities; these patients in general require surgery to repair or replace the valve.