Definition
Aortic stenosis (AS) is a narrowing of the aortic valve in the heart. This valve is located between the left ventricle (lower pumping chamber) and the aorta. The aorta is the largest artery in the body. It transports blood from the heart throughout the body. The aortic valve has three cusps, or flaps, that control the direction and flow of the blood. Aortic stenosis causes obstruction or blockage of blood flow through this valve.
