Mitral valve stenosis

Overview

Mitral valve stenosis — sometimes called mitral stenosis — is a narrowing of the valve between the two left heart chambers. The narrowed valve reduces or blocks blood flow into the heart's main pumping chamber. The heart's main pumping chamber is the lower left heart chamber, also called the left ventricle.

Mitral valve stenosis can make you tired and short of breath. Other symptoms may include irregular heartbeats, dizziness, chest pain or coughing up blood. Some people don't notice symptoms.

Mitral valve stenosis can be caused by a complication of strep throat called rheumatic fever. Rheumatic fever is now rare in the United States.

Treatment for mitral valve stenosis may include medication or mitral valve repair or replacement surgery. Some people only need regular health checkups. Treatment depends on the severity of the condition and whether it's getting worse. Untreated, mitral valve stenosis can lead to serious heart complications.

Typical heart and heart with mitral valve stenosis

Mitral valve stenosis, shown in the heart on the right, is a condition in which the heart's mitral valve is narrowed. The valve doesn't open properly, blocking blood flow coming into the left ventricle, the main pumping chamber of the heart. A typical heart is shown on the left.

Symptoms

Mitral valve stenosis usually worsens slowly. You may not have any symptoms, or you may have mild ones for many years. Symptoms of mitral valve stenosis can occur at any age — even during childhood.

Symptoms of mitral valve stenosis include:

  • Shortness of breath, especially with activity or when you lie down
  • Fatigue, especially during increased activity
  • Swollen feet or legs
  • Sensations of a fast, fluttering or pounding heartbeat
  • Dizziness or fainting
  • Irregular heart sound, also called a heart murmur
  • Fluid buildup in the lungs
  • Irregular heart rhythms
  • Chest discomfort or chest pain
  • Coughing up blood

Mitral valve stenosis symptoms may appear or get worse when the heart rate increases, such as during exercise. Anything that puts stress on the body, including pregnancy or infections, may trigger symptoms.

When to see a doctor

Call your health care provider for an immediate appointment if you have chest pain, a fast, fluttering or pounding heartbeat, or shortness of breath during activity. Your provider might recommend that you visit a doctor trained in heart diseases. This type of care provider is called a cardiologist.

If you have been diagnosed with mitral valve stenosis but haven't had symptoms, ask your provider about how often you should have follow-up exams.

Causes

To understand the causes of mitral valve disease, it may be helpful to know how the heart typically works.

The mitral valve is one of four valves in the heart that keep blood flowing in the right direction. Each valve has flaps — called leaflets — that open and close once during each heartbeat. If a valve doesn't open or close properly, blood flow through the heart to the body can be reduced.

In mitral valve stenosis, the valve opening narrows. The heart now must work harder to force blood through the smaller valve opening. Blood flow between the upper left and lower left heart chambers may decrease.

Causes of mitral valve stenosis include:

  • Rheumatic fever. This complication of strep throat is the most common cause of mitral valve stenosis. When rheumatic fever damages the mitral valve, the condition is called rheumatic mitral valve disease. The valve disease symptoms may not be seen until years to decades after rheumatic fever.
  • Calcium deposits. As you age, calcium deposits can build up around the mitral valve. This can cause narrowing of the structures that support the mitral valve flaps. The condition is called mitral annular calcification, or MAC for short. Severe MAC can cause mitral stenosis symptoms. It's difficult to treat even with surgery. People with calcium around the mitral valve often have similar problems with the heart's aortic valve.
  • Radiation therapy. This is a treatment for certain types of cancer. Radiation to the chest area can sometimes cause the mitral valve to thicken and harden. The heart valve damage typically occurs 20 to 30 years after radiation therapy.
  • Heart problem present at birth, also called a congenital heart defect. Rarely, some babies are born with a narrowed mitral valve that causes problems over time.
  • Other health conditions. Lupus and other autoimmune conditions may rarely cause mitral valve stenosis.
The left and right atria and left and right ventricles

A typical heart has two upper and two lower chambers. The upper chambers, the right and left atria, receive incoming blood. The lower chambers, the more muscular right and left ventricles, pump blood out of the heart. The heart valves, which keep blood flowing in the right direction, are gates at the chamber openings.

Risk factors

Risk factors for mitral valve stenosis include:

  • Untreated strep infections. A history of untreated strep throat or rheumatic fever increases the risk of mitral valve stenosis. However, rheumatic fever is rare in the United States. But it's still a problem in developing nations.
  • Aging. Older adults are at increased risk of calcium buildup around the mitral valve.
  • Radiation therapy. Radiation causes changes in the mitral valve shape and structure. Rarely, people who receive radiation therapy to the chest area for certain types of cancer may develop mitral valve stenosis.
  • Illegal drug use. MDMA, short for 3,4-methylenedioxymethamphetamine and commonly called molly or ecstasy, increases the risk of mitral valve disease.
  • Use of certain medicines. Some migraine drugs contain a class of medicine called ergot alkaloids. Ergotamine is an example. Ergot alkaloids may rarely cause heart valve scarring that leads to mitral stenosis. Older weight-loss drugs that contained fenfluramine (Pondimin) or dexfenfluramine (Redux) also are linked to heart valve disease and other heart problems. Fen-phen is an example. It's no longer sold in the United States.

Complications

Untreated, mitral valve stenosis can lead to complications such as:

  • Irregular heartbeats. Irregular heartbeats are called arrhythmias. Mitral valve stenosis may cause an irregular and chaotic heart rhythm called atrial fibrillation. It's commonly known as AFib. AFib is a common complication of mitral stenosis. The risk increases with age and more-severe stenosis.
  • Blood clots. Irregular heartbeats linked to mitral valve stenosis can cause blood clots to form in the heart. If a blood clot from the heart travels to the brain, a stroke can occur.
  • High blood pressure in the lung arteries. The medical name for this condition is pulmonary hypertension. It can occur if a narrowed mitral valve slows or blocks blood flow. Decreased blood flow raises pressure in the lung arteries. The heart must work harder to pump blood through the lungs.
  • Right-sided heart failure. Changes in blood flow and high pressure in the lung arteries put a strain on the heart. The heart must work harder to pump blood to the right-sided heart chambers. The extra effort eventually causes the heart muscle to become weak and fail.

Prevention

Rheumatic fever is the most common cause of mitral valve stenosis. So the best way to prevent mitral valve stenosis is to prevent rheumatic fever. You can do this by making sure you and your children see a health care provider for sore throats. Untreated strep throat infections can develop into rheumatic fever. Strep throat is usually easily treated with antibiotics.

Diagnosis

To diagnosis mitral valve stenosis, your health care provider examines you and asks questions about your symptoms and medical history. You'll also be asked about your family's medical history.

The provider listens to your heart with a device called a stethoscope. Mitral valve stenosis often causes an irregular heart sound due to the narrowed opening. This is called a heart murmur. The provider also uses the stethoscope to listen to your lungs. Mitral valve stenosis can cause fluid buildup in the lungs. Your provider might call this congestion.

If you have symptoms of mitral valve stenosis, tests are done to examine the heart.

Tests

Imaging tests can check your heart health. Some can confirm mitral valve stenosis and help determine its cause. Test results can help your provider plan the best treatment for you.

Tests may include:

  • Echocardiogram. An echocardiogram can confirm mitral stenosis. Sound waves create images of the beating heart. The test can identify areas of poor blood flow and heart valve problems. It also can help determine the severity of mitral valve stenosis.

    In a standard echocardiogram — called a transthoracic echocardiogram — sound waves are directed at the heart using a wandlike device called a transducer. The device is pressed firmly against the skin on the chest area.

    If more-detailed images are needed, another type of echocardiogram may be done. This test is called a transesophageal echocardiogram. A wandlike device attached to the end of a tube is inserted down the throat and esophagus, which is closer to the heart and thus gives more-detailed imaging of the structures of the heart. The throat is numbed for this type of echocardiogram.

    If you are diagnosed with very severe mitral stenosis, you should get an echocardiogram every year. Those with less severe mitral stenosis need an echocardiogram about every 3 to 5 years. Ask your provider how often you'll need one.

  • Electrocardiogram. Also called an ECG or EKG, this quick and painless test measures the electrical activity of the heart. Sticky patches called electrodes are placed on the chest and sometimes the arms and legs. Wires connect the electrodes to a computer, which displays the test results. An ECG shows how fast or how slow the heart is beating. A health care provider can look for signal patterns to determine if there's an irregular heartbeat.
  • Chest X-ray. A chest X-ray shows the condition of the heart and lungs. It can tell whether the heart is enlarged, which can be a sign of certain types of heart valve disease.
  • Exercise stress tests. These tests often involve walking on a treadmill or riding a stationary bike while the heart is monitored. Exercise tests help show how the heart responds to physical activity and whether valve disease symptoms occur during exercise. If you can't exercise, you might be given medications that mimic the effect of exercise on your heart.
  • Cardiac CT. This test combines several X-ray images to provide a more detailed cross-sectional view of the heart and the heart valves. A cardiac CT is commonly done to evaluate mitral stenosis that isn't caused by rheumatic fever.
  • Cardiac MRI. This test uses magnetic fields and radio waves to create detailed images of the heart. A cardiac MRI might be done to determine the severity of mitral valve stenosis.
  • Cardiac catheterization. This test isn't often used to diagnose mitral stenosis, but it may be done if other tests aren't able to diagnose the condition or determine its severity. A long, thin flexible tube called a catheter is inserted in a blood vessel, usually in the groin or wrist. It's guided to the heart. Dye flows through the catheter to arteries in the heart. The dye helps the arteries show up more clearly on X-ray images and video.

Treatment

Staging

After testing confirms a diagnosis of mitral or other heart valve disease, your health care provider may tell you the stage of disease. Staging helps determine the most appropriate treatment.

The stage of heart valve disease depends on many things, including symptoms, disease severity, the structure of the valve or valves, and blood flow through the heart and lungs.

Heart valve disease is staged into four basic groups:

  • Stage A: At risk. Risk factors for heart valve disease are present.
  • Stage B: Progressive. Valve disease is mild or moderate. There are no heart valve symptoms.
  • Stage C: Asymptomatic severe. There are no heart valve symptoms, but the valve disease is severe.
  • Stage D: Symptomatic severe. Heart valve disease is severe and is causing symptoms.

A doctor trained in heart disease typically provides care for people with mitral valve stenosis. This type of provider is called a cardiologist.

If you have mild to moderate mitral valve stenosis with no symptoms, you might not need immediate treatment. Instead, you'll have regular checkups with your provider to see if your condition gets worse.

Treatments for mitral valve stenosis include medications, mitral valve repair or mitral valve replacement, or open-heart surgery.

Medications

Medications are used to reduce the symptoms of mitral valve stenosis.

Your provider might prescribe one or more of the following medications:

  • Diuretics to reduce fluid buildup in the lungs or other areas of the body.
  • Blood thinners, called anticoagulants, to help prevent blood clots if you have a certain irregular heart rhythm called atrial fibrillation.
  • Beta blockers, calcium channel blockers or other heart drugs to slow the heart rate.
  • Heart rhythm drugs to treat atrial fibrillation or other irregular heart rhythms. These types of drugs are called anti-arrhythmics.
  • Antibiotics to prevent a return of rheumatic fever if that's what damaged the mitral valve.

Surgery or other procedures

A diseased or damaged mitral valve might eventually need to be repaired or replaced, even if you don't have symptoms. If you need surgery for another heart condition, a surgeon might perform mitral valve repair or replacement at the same time.

Together you and your care provider can discuss the best treatment for you. Surgeries and procedures for mitral valve stenosis may include:

  • Balloon valvuloplasty. This procedure is done to repair a mitral valve with a narrowed opening. It uses a hollow, flexible tube called a catheter and a tiny balloon. The provider inserts the balloon-tipped catheter into an artery, usually in the groin. It's guided to the mitral valve. The balloon is inflated, widening the mitral valve opening. The balloon is deflated. Then the catheter and balloon are removed.

    Valvuloplasty might be done even if you don't have symptoms. But not everyone with mitral valve stenosis is a candidate for the procedure. Talk to your provider to decide whether it's an option for you.

    This procedure is a type of transcatheter intervention therapy. Other names for the procedure are mitral balloon valvotomy, percutaneous mitral balloon commissurotomy or percutaneous transvenous mitral commissurotomy.

  • Open-heart surgery to repair the valve. If a catheter procedure isn't an option, an open-heart surgery called open valvotomy may be done. The surgery also may be called surgical commissurotomy. It removes calcium deposits and other scar tissue blocking the mitral valve opening. The heart must be stopped to prevent bleeding in the chest area during this surgery. A heart-lung machine temporarily takes over the heart's job. The procedure may need to be repeated if mitral valve stenosis returns.
  • Mitral valve replacement. If the mitral valve can't be repaired, surgery may be done to replace the damaged valve. The damage valve is replaced with a mechanical one or a valve made from cow, pig or human heart tissue. A valve made from animal or human tissue is called a biological tissue valve.

    Biological tissue valves break down over time and may need to be replaced. People with mechanical valves need lifelong blood thinners to prevent blood clots. Together you and your health care provider should discuss the benefits and risks of each type of valve to choose the best option for you.

The outlook for people who have a procedure or surgery for mitral stenosis is generally good. But older age, poor health, and a lot of calcium buildup on or around the valves increase the risk of surgery complications. Long-term pulmonary hypertension may worsen the prognosis after valve surgery.

Lifestyle and home remedies

Lifestyle changes can help improve heart health. If you have mitral valve stenosis, your health care provider may recommend that you:

  • Eat a heart-healthy diet. Eat a variety of fruits and vegetables, low-fat or fat-free dairy products, poultry, fish, and whole grains. Avoid saturated and trans fat. Use less salt and sugar.
  • Limit salt. Salt in food and drinks may increase pressure on the heart. Avoid high-sodium foods. Don't add salt to food. Read food labels and ask for low-salt dishes when eating out.
  • Maintain a healthy weight. If you are overweight or have obesity, your health care provider might recommend that you lose weight. Ask your provider what a healthy weight is for you.
  • Don't smoke or use tobacco. If you smoke, quit. Ask your health care provider about resources to help you quit smoking. Joining a support group may be helpful.
  • Limit alcohol and other stimulants. Heavy alcohol use, caffeine, nicotine and other stimulants can cause the heart to beat faster. Stimulants can make irregular heart rhythms, also called arrhythmias, worse.
  • Ask about exercise. How long and hard you're able to exercise may depend on the severity of mitral valve stenosis and the intensity of exercise. Talk to your health care provider about the amount and type of exercise that's best for you, especially if you're considering competitive sports. People with severe mitral stenosis should not play competitive sports.
  • Get regular health checkups. Regular visits with a health care provider are important if you have mitral valve stenosis. You'll need an echocardiogram at least every year. If you frequently feel your heart pounding or beating fast, get medical help. Fast heart rhythms that aren't treated can quickly get worse in people with mitral valve stenosis.
  • Manage stress. Find ways to help manage stress, such as through relaxation activities, meditation, physical activity, and spending time with family and friends.
  • Practice good sleep habits. Poor sleep may increase the risk of heart disease and other chronic conditions. Adults should aim to get 7 to 9 hours of sleep daily. Kids often need more. Go to bed and wake at the same time every day, including on weekends. If you have trouble sleeping, talk to your provider about strategies that might help.

Pregnancy

If you have mitral valve stenosis and want to become pregnant, it's important to talk with a health care provider first. Pregnancy causes the heart to work harder. How a heart with mitral valve stenosis handles the extra work depends on the degree of valve narrowing and how well the heart pumps. If you are pregnant and have mitral valve stenosis, your care providers should closely monitor you. A health care provider can explain which medications are safe to take during pregnancy. You and your provider also can discuss whether a procedure is needed to treat a heart valve condition before pregnancy.

Preparing for an appointment

Your primary care provider may be the first to think you have mitral valve stenosis. After your first appointment, your provider may refer you to a cardiologist.

Here's some information to help you prepare for your appointment.

What you can do

  • Write down your symptoms and when they started.
  • List important medical information, including other health problems and any family history of heart disease.
  • List all the medicines you take, including those bought without a prescription. Include dosages.
  • Take a family member or friend to the appointment, if possible. Someone who goes with you may help you better remember any information.
  • Write down the questions to ask your care provider.

Questions to ask your health care provider at the first appointment include:

  • What is likely causing my symptoms?
  • Are there other possible causes for these symptoms?
  • What tests do I need?
  • Should I see a specialist?
  • Do I need to avoid any activities or change my diet before my cardiologist appointment?

Questions to ask if you are referred to a cardiologist include:

  • What is my diagnosis?
  • What treatment do you recommend?
  • What are the possible side effects of the medications you're recommending?
  • What will my recovery be like from the procedure you're recommending?
  • How will you monitor my health over time?
  • What is my risk of long-term complications from this condition?
  • What restrictions do I need to follow?
  • Will physical activity, including sex, increase my risk of complications?
  • What diet and lifestyle changes should I make?
  • I have these other health problems. How can I best manage them together?

It's important for you to understand your condition. Don't hesitate to ask other questions.

What to expect from your doctor

The health care provider who sees you for possible mitral valve stenosis may ask:

  • What are your symptoms?
  • When did your symptoms begin?
  • Do you always have symptoms, or do they come and go?
  • Do you have rapid, fluttering or pounding heartbeats?
  • Have you coughed up blood?
  • Does exercise or physical activity make your symptoms worse?
  • Do you have any family members with heart valve disease?
  • Have you had rheumatic fever?
  • Are you being treated or have you recently been treated for any other health conditions?
  • Do you or did you smoke? How much? When did you quit?
  • Do you use alcohol or caffeine? How much?
  • Are you planning to become pregnant in the future?

What you can do in the meantime

While you wait for your appointment, ask family members whether close relatives have heart disease. The symptoms of mitral valve stenosis are similar to other heart conditions. Some can occur in families. Knowing about your family's health history helps your care provider determine your diagnosis and treatment.

If exercise makes your symptoms worse, avoid it until you've seen your health care provider.

Last Updated Oct 7, 2022


© 2022 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. Terms of Use