The most common cause in people younger than 70 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 Overview of Heart Valve Disorders Heart valves regulate the flow of blood through the heart's four chambers—two small, round upper chambers (atria) and two larger, cone-shaped lower chambers (ventricles). Each ventricle has... read more .)
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 Aortic Regurgitation Aortic regurgitation is leakage of blood back through the aortic valve each time the left ventricle relaxes. Aortic regurgitation is due to deterioration of the aortic valve and the surrounding... read more ) 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 Heart Failure (HF) Heart failure is a disorder in which the heart is unable to keep up with the demands of the body, leading to reduced blood flow, back-up (congestion) of blood in the veins and lungs, and/or... read more . The abnormal aortic valve can rarely become infected (infective endocarditis Infective Endocarditis Infective endocarditis is an infection of the lining of the heart (endocardium) and usually also of the heart valves. Infective endocarditis occurs when bacteria enter the bloodstream and travel... read more ).
Causes of Aortic Stenosis
In North America and Western Europe, aortic stenosis is mainly a disease of older people—the result of scarring and calcium accumulation (calcification) in the valve cusps. In such cases, aortic stenosis becomes evident after age 60 but does not usually cause symptoms until age 70 or 80.
Aortic stenosis may also result from rheumatic fever Rheumatic Fever Rheumatic fever is inflammation of the joints, heart, skin, and nervous system, resulting from a complication of untreated streptococcal infection of the throat. This condition is a reaction... read more contracted in childhood. Rheumatic fever is the most common cause in regions where antibiotics are not widely used.
In people under 70, the most common cause is a birth defect Overview of Heart Defects About one in 100 babies is born with a heart defect. Some are severe, but many are not. Defects may involve abnormal formation of the heart's walls or valves or of the blood vessels that enter... read more , such as a valve with only two cusps Bicuspid Aortic Valve A bicuspid aortic valve is an aortic valve that has 2 cusps (leaflets) instead of the normal 3. The aortic valve is the valve that opens with each heartbeat to allow blood to flow from the heart... read more instead of the usual three or a valve with an abnormal funnel shape. The narrowed aortic valve opening may not be a problem during infancy, but problems occur as a person grows. The valve opening remains the same size, but the heart grows and enlarges further as it tries to pump increasing amounts of blood through the small valve opening. Over the years, the opening of a defective valve often becomes stiff and narrow because calcium accumulates.
Symptoms of Aortic Stenosis
People who develop aortic stenosis as a result of a birth defect may not develop symptoms until adulthood.
Chest tightness (angina Angina Angina is temporary chest pain or a sensation of pressure that occurs while the heart muscle is not receiving enough oxygen. A person with angina usually has discomfort or pressure beneath the... read more ) may occur during exertion. The symptoms go away with several minutes of rest. People with heart failure Heart Failure (HF) Heart failure is a disorder in which the heart is unable to keep up with the demands of the body, leading to reduced blood flow, back-up (congestion) of blood in the veins and lungs, and/or... read more develop fatigue and shortness of breath during exertion.
People who have severe aortic stenosis may faint during exertion because blood pressure may fall suddenly. Fainting usually occurs without any warning symptoms (such as dizziness or light-headedness).
Diagnosis of Aortic Stenosis
Doctors usually base the diagnosis on a characteristic heart murmur heard through a stethoscope and on results of echocardiography Echocardiography and Other Ultrasound Procedures Ultrasonography uses high-frequency (ultrasound) waves bounced off internal structures to produce a moving image. It uses no x-rays. Ultrasonography of the heart (echocardiography) is one of... read more . Echocardiography is the best procedure for assessing the severity of aortic stenosis (by measuring how small the valve opening is) and the function of the left ventricle.
For people who have aortic stenosis but do not have symptoms, doctors often do a stress test Stress Testing Stressing the heart (by exercise or by use of stimulant drugs to make the heart beat faster and more forcibly) can help identify coronary artery disease. In coronary artery disease, blood flow... read more . People who experience angina, shortness of breath, or faintness during the stress test are at risk of complications and may need treatment.
If the stress test is abnormal or if the person develops symptoms, cardiac catheterization Cardiac catheterization Cardiac catheterization and coronary angiography are minimally invasive methods of studying the heart and the blood vessels that supply the heart (coronary arteries) without doing surgery. These... read more is necessary to determine whether the person also has coronary artery disease Overview of Coronary Artery Disease (CAD) Coronary artery disease is a condition in which the blood supply to the heart muscle is partially or completely blocked. The heart muscle needs a constant supply of oxygen-rich blood. The coronary... read more . Cardiac catheterization Cardiac catheterization Cardiac catheterization and coronary angiography are minimally invasive methods of studying the heart and the blood vessels that supply the heart (coronary arteries) without doing surgery. These... read more is often done when surgery is planned to replace an aortic valve so that doctors can identify coronary artery disease that could also be treated during the heart surgery.
Treatment of Aortic Stenosis
Adults who have aortic stenosis but no symptoms should see their doctor regularly and should avoid overly stressful exercise. Echocardiography Echocardiography and Other Ultrasound Procedures Ultrasonography uses high-frequency (ultrasound) waves bounced off internal structures to produce a moving image. It uses no x-rays. Ultrasonography of the heart (echocardiography) is one of... read more is done periodically, at intervals determined by the severity of the stenosis, to monitor heart and valve function.
Before surgery, heart failure is treated with diuretics (see table Some Drugs Used to Treat Heart Failure Some Drugs Used to Treat Heart Failure ). Treating angina is often difficult because nitroglycerin, which is used to treat angina in people who have coronary artery disease, can rarely cause dangerously low blood pressure and worsen the angina in people with aortic stenosis.
Sometimes, in children and young adults who were born with a defective valve, the valve can be stretched open using a procedure called balloon valvotomy. In this procedure, a catheter with a balloon on the tip is threaded through a vein or artery into the heart (cardiac catheterization Cardiac catheterization Cardiac catheterization and coronary angiography are minimally invasive methods of studying the heart and the blood vessels that supply the heart (coronary arteries) without doing surgery. These... read more ). Once across the valve, the balloon is inflated, separating the valve cusps.
In people who have aortic stenosis that causes any symptoms (particularly shortness of breath on exertion, angina, or fainting), or if the left ventricle begins to fail, then the aortic valve is replaced. Replacement of the abnormal valve is the best treatment for nearly everyone, and the prognosis after valve replacement is excellent. Aortic valve replacement was traditionally done via open-heart surgery.
Increasingly, older people can have their valve replaced through a catheter threaded up the femoral artery in a procedure called transcatheter aortic valve implantation (TAVI). TAVI is generally better than medical therapy and similar to surgical valve replacement for these people.
People with an artificial valve must take antibiotics before a surgical, dental, or medical procedure (see table Examples of Procedures That Require Preventive Antibiotics Examples of Procedures That Require Preventive Antibiotics in the United States* ) to reduce the risk of an infection on the valve (infective endocarditis).
The following is an English-language resource that may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
American Heart Association: Heart Valve Disease: Provides comprehensive information on diagnosis and treatment of diseases of the heart valves