heart and blood vessel disorders
Aortic Stenosis
Introduction
Aortic stenosis is a narrowing of the aortic valve opening that blocks (obstructs) blood flow from the left ventricle to the aorta. The most common cause in people younger than 70 years is a birth defect that affects the valve. In people over 70, the most common cause is thickening of the valve cusps (aortic sclerosis). People may have chest tightness, feel short of breath, or faint. Doctors usually base the diagnosis on a characteristic heart murmur heard through a stethoscope and on results of echocardiography. People see their doctors regularly so their condition can be monitored, and people with symptoms may undergo replacement of the valve. (See also Overview of Heart Valve Disorders and the video The aortic valve is in the opening between the left ventricle and the aorta. The aortic valve opens as the left ventricle contracts to pump blood into the aorta. If a disorder causes the valve flaps to become thick and stiff, the valve opening is narrowed (stenosis). Sometimes the stiffened valve also fails to close completely and blood from the aorta leaks back through the aortic valve into the heart ( Aortic Regurgitation ) each time the left ventricle relaxes. In aortic stenosis, the muscular wall of the left ventricle usually becomes thicker as the ventricle works harder to pump blood through the narrowed valve opening into the aorta. The thickened heart muscle requires an increasing supply of blood from the coronary arteries, and sometimes, especially during exercise, the blood supply does not meet the needs of the heart muscle. The insufficient blood supply can cause chest tightness, fainting, and sometimes sudden death. The heart muscle may also begin to weaken, leading to Heart Failure (HF) . The abnormal aortic valve can rarely become infected ( 