Aortic valve stenosis

December 31, 2014

Synonyms

Overview

Aortic valve stenosis (or aortic stenosis) occurs when the heart's aortic valve narrows. This narrowing prevents the valve from opening fully, which obstructs blood flow from your heart into your aorta and onward to the rest of your body.

When the aortic valve is obstructed, your heart needs to work harder to pump blood to your body. Eventually, this extra work limits the amount of blood it can pump and may weaken your heart muscle.

Symptoms

Aortic valve stenosis ranges from mild to severe. Aortic valve stenosis signs and symptoms generally develop when narrowing of the valve is severe and can include:

Chest pain (angina) or tightness
Feeling faint or fainting with exertion
Shortness of breath, especially with exertion
Fatigue, especially during times of increased activity
Heart palpitations - sensations of a rapid, fluttering heartbeat
Heart murmur

The heart-weakening effects of aortic valve stenosis may lead to heart failure. Heart failure signs and symptoms include fatigue, shortness of breath, and swollen ankles and feet.

Causes

Aortic valve stenosis is narrowing of the aortic valve. Many things can narrow this passageway between your heart and aorta. Causes of aortic valve stenosis include:

Congenital heart defect:

The aortic valve consists of three tightly fitting, triangular-shaped flaps of tissue called leaflets. Some children are born with an aortic valve that has only one (unicuspid), two (bicuspid) or four (quadricuspid) leaflets — not three. This deformity may not cause any problems until adulthood, at which time the valve may begin to narrow or leak and may need to be repaired or replaced.

Having a congenitally abnormal aortic valve requires regular evaluation by a doctor to watch for signs of valve problems. In most cases, doctors don't know why a heart valve fails to develop properly, so it isn't something you could have prevented.

Calcium buildup on the valve:

With age, heart valves may accumulate deposits of calcium (aortic valve calcification). Calcium is a mineral found in your blood. As blood repeatedly flows over the aortic valve, deposits of calcium can accumulate on the valve's leaflets. These deposits may never cause any problems. These calcium deposits aren't linked to taking calcium tablets or drinking calcium-fortified drinks.

However, in some people — particularly those with a congenitally abnormal aortic valve, such as a bicuspid aortic valve — calcium deposits result in stiffening of the leaflets of the valve. This stiffening narrows the aortic valve and can occur at a younger age. However, aortic valve stenosis that is related to increasing age and the buildup of calcium deposits on the aortic valve is most common in men older than 65 and women older than 75.

Rheumatic fever:

A complication of strep throat infection, rheumatic fever may result in scar tissue forming on the aortic valve. Scar tissue alone can narrow the aortic valve and lead to aortic valve stenosis. Scar tissue can also create a rough surface on which calcium deposits can collect, contributing to aortic valve stenosis later in life.

Rheumatic fever may damage more than one heart valve, and in more than one way. A damaged heart valve may not open fully or close fully - or both. While rheumatic fever is rare in the United States, some older adults had rheumatic fever as children.

Prevention

Some possible ways to prevent aortic valve stenosis include:

Taking steps to prevent rheumatic fever:

You can do this by making sure you see your doctor when you have a sore throat. Untreated strep throat can develop into rheumatic fever. Fortunately, strep throat can usually be easily treated with antibiotics. Rheumatic fever is more common in children and young adults.

Addressing risk factors for coronary artery disease:

These include high blood pressure, obesity and high cholesterol levels. These factors may be linked to aortic valve stenosis, so it's a good idea to keep your weight, blood pressure and cholesterol levels under control if you have aortic valve stenosis.

Taking care of your teeth and gums:

There may be a link between infected gums (gingivitis) and infected heart tissue (endocarditis). Inflammation of heart tissue caused by infection can narrow arteries and aggravate aortic valve stenosis.

Diagnosis

Physical examination:

As part of a routine physical exam, your doctor uses a stethoscope to listen to your heart. He or she is listening for, among other things, an abnormal heart sound (heart murmur).

Echocardiogram:

This test uses sound waves to produce an image of your heart. This is the primary test your doctor may use to diagnose your condition if he or she suspects you have a heart valve condition. In an echocardiogram, sound waves are directed at your heart from a wandlike device (transducer) held on your chest. The sound waves bounce off your heart and are reflected back through your chest wall and processed electronically to provide video images of your heart.

An echocardiogram helps your doctor closely examine the heart and heart valves to check for any problems or abnormalities. This test helps your doctor to diagnose aortic valve stenosis, evaluate the severity of your condition and determine the most appropriate treatment for your condition. An echocardiogram will also be used to monitor your condition over time.

In some cases, your doctor may insert a tube with a transducer attached to it and guide it down your throat into your esophagus (transesophageal echocardiogram) while you are sedated. This type of echocardiogram may offer more detailed images of your heart.

Electrocardiogram (ECG):

In this test, patches with wires (electrodes) are attached to your skin to measure the electrical impulses given off by your heart. Impulses are recorded as waves displayed on a monitor or printed on paper. An ECG can provide clues about whether the left ventricle is thickened or enlarged, a problem which can occur with aortic valve stenosis.

Chest X-ray:

An X-ray image of your chest allows your doctor to check the size and shape of your heart to determine whether the left ventricle is enlarged — a possible indicator of aortic valve stenosis.

A chest X-ray can also reveal calcium deposits on the aortic valve. In addition, a chest X-ray helps your doctor check the condition of your lungs. Aortic valve stenosis may lead to blood and fluid backing up in your lungs, which causes congestion that may be visible on an X-ray.

Cardiac catheterization:

Your doctor may order this procedure if noninvasive tests haven't provided enough information to firmly diagnose the type or severity of your heart condition. In this procedure, your doctor threads a thin tube (catheter) through an artery in your arm or groin and guides it to an artery in your heart.

Doctors may inject a dye through the catheter, which helps your arteries become visible on an X-ray (coronary angiogram). This test helps show any blockages in arteries to your heart that can coexist with aortic valve stenosis that may need surgical treatment along with aortic valve stenosis.

Exercise tests:

In exercise tests, you exercise to increase your heart rate and make your heart work harder. If you have severe aortic valve stenosis but aren't experiencing symptoms, your doctor may order exercise tests to evaluate how your heart responds to exertion (exercise) and to measure your tolerance for activity.

Computerized tomography (CT) scan:

A CT scan uses a series of X-rays to create detailed images of your heart and heart valves. Doctors may use this test to measure the size of your aorta and look at your aortic valve more closely. Sometimes doctors may inject a dye into your blood vessels to show the blood flow (CT angiography).

Magnetic resonance imaging (MRI):

An MRI uses powerful magnets and radio waves to create detailed images of your heart and heart valves. Doctors may inject a dye into your blood vessels to highlight the heart and blood vessels in images (magnetic resonance angiography). Doctors may use this test to measure the size of your aorta.

Prognosis

The prognosis for aortic valve stenosis depends on the severity of the disease. With surgical repair, the disease is curable. Patients suffering mild stenosis can usually lead a normal life; a minority of the patients progress to severe disease. Anyone with moderate stenosis should avoid vigorous physical activity. Most of these patients end up suffering some kind of coronary heart disease over a 10 year period. Because it is a progressive disease, moderate and severe stenosis will be treated ultimately with surgery. Severe disease, if left untreated, leads to death within 2 to 4 years once the symptoms start.

Treatment

Medications

No medications can reverse aortic valve stenosis. However, your doctor may prescribe certain medications to help your symptoms, such as ones to reduce fluid accumulation, to slow your heart rate or to control heart rhythm disturbances associated with aortic valve stenosis. Lowering blood pressure may prevent or slow the development of aortic stenosis. Ask your doctor if you need to lower your blood pressure with medications.

Procedures

You may need valve repair or replacement to treat aortic valve stenosis. Although less invasive approaches are possible in some cases, surgery is the primary treatment for this condition.

Therapies to repair or replace the aortic valve include:

Balloon valvuloplasty.

Occasionally, balloon valvuloplasty is an option. Balloon valvuloplasty uses a soft, thin tube (catheter) tipped with a balloon.

A doctor guides the catheter through a blood vessel in your groin to your heart and into your narrowed aortic valve. Once in position, a balloon at the tip of the catheter is inflated. The balloon pushes open the aortic valve and stretches the valve opening, improving blood flow. The balloon is then deflated, and the catheter with the balloon is guided back out of your body.

Balloon valvuloplasty may relieve aortic valve stenosis and its symptoms, especially in infants and children. However, in adults, the valve tends to narrow again even after initial success. For these reasons, doctors rarely use balloon valvuloplasty today to treat aortic valve stenosis in adults, except in people who are too sick to undergo surgery or are waiting for a transcatheter aortic valve replacement.

Aortic valve replacement.

This is the primary surgical treatment for severe aortic valve stenosis. Your surgeon removes the narrowed aortic valve and replaces it with a mechanical valve or a tissue valve. This procedure is generally performed during open-heart surgery.

Mechanical valves, made from metal, are durable, but they carry the risk of blood clots forming on or near the valve. If you receive a mechanical valve, you'll need to take an anticoagulant medication, such as warfarin (Coumadin), for life to prevent blood clots.

Tissue valves — which may come from a pig, cow or human deceased donor — often eventually narrow over the years and need to be replaced. Another type of tissue valve replacement that uses your own pulmonary valve (autograft) is sometimes possible but less likely in an older person. Your doctor can discuss the risks and benefits of each type of heart valve with you. Aortic valve replacement can relieve aortic valve stenosis and its symptoms.

Transcatheter aortic valve replacement (TAVR).

Aortic valve replacement, the most common treatment for aortic valve stenosis, has traditionally been performed with open-heart surgery.

A less invasive approach — transcatheter aortic valve replacement — involves replacing the aortic valve with a prosthetic valve via the femoral artery in your leg (transfemoral) or the left ventricular apex of your heart (transapical).

In TAVR, doctors insert a catheter with a balloon at the tip in an artery in your leg or in a small incision in your chest and guide it to your heart and into your aortic valve. A balloon at the tip of the catheter, which has a folded valve around it, is then inflated. This pushes open the aortic valve and stretches the valve opening and expands the folded valve into the aortic valve. Doctors then deflate the balloon and guide the catheter with the balloon back out of your body. Alternatively, a self-expanding valve may be inserted into the aortic valve, and a balloon then isn't used.

In some cases, a valve can be inserted via a catheter into a tissue replacement valve that needs to be replaced (valve-in-valve procedure).

TAVR is usually reserved for individuals with severe aortic valve stenosis who are at increased risk of complications from aortic valve surgery. This procedure can relieve severe aortic valve stenosis and its symptoms in those who are at increased risk of complications from aortic valve surgery. TAVR has a higher risk of stroke and vascular complications than aortic valve replacement surgery. The technique is relatively new and is evolving quickly, and there are newer valves and indications occurring frequently. TAVR is sometimes referred to as transcatheter aortic valve implantation (TAVI).

Surgical valvuloplasty.

In rare cases, surgical repair may be a more effective option than balloon valvuloplasty, such as in infants born with an aortic valve in which the leaflets of the valve are fused together. Using traditional surgical tools, a cardiac surgeon operates on the valve and separates these leaflets to reduce stenosis and improve blood flow.

Aortic valve stenosis can be treated effectively with surgery. However, you'll need regular follow-up appointments with your doctor to check for any changes in your condition. You may still be at risk of irregular heart rhythms even after you've been treated for aortic valve stenosis. You may need to take medications to lower that risk. If your heart has become weakened from aortic valve stenosis, you may need medications to treat heart failure.