Mitral Valve Stenosis
What is mitral valve stenosis?
Mitral valve stenosis is a heart problem in which the mitral valve doesn't open as wide as it should. The valve becomes stiff or scarred, or the valve flaps become partially joined together.
See a picture of mitral valve stenosis .
Mitral valve stenosis can lead to heart failure ; a stroke; an infection in the heart ( endocarditis ); or a fast, slow, or uneven heartbeat ( arrhythmia ). Fortunately, mitral valve stenosis can be treated.
Mitral valve stenosis is not common in developed countries such as the United States, Canada, and western Europe.
How does the mitral valve work?
Your heart has four chambers and four valves. The valves have flaps, or leaflets. The flaps open and close to keep blood flowing in the proper direction through your heart.
The mitral valve connects the heart's upper left chamber (left atrium) to the lower left chamber (left ventricle). When the heart pumps, blood forces the flaps open, and blood flows from the left atrium to the left ventricle. Between heartbeats, the flaps close tightly so that blood does not leak backward through the valve.
With mitral valve stenosis, not as much blood can flow into the left ventricle. More blood stays in the left atrium, and blood may back up into the lungs.
See a picture of the heart and its chambers, valves, and blood flow .
See a picture of a normal mitral valve .
What causes mitral valve stenosis?
Nearly all cases of mitral valve stenosis are caused by rheumatic fever . This fever results from an untreated strep infection, most often strep throat . But many people who have mitral valve stenosis don't realize that they had rheumatic fever.
What are the symptoms?
Symptoms usually don't develop until 10 to 20 years after stenosis starts, and they may take as long as 40 years to develop.
When symptoms first appear, they usually are mild. You may only have a few symptoms, even if your mitral valve is very narrow. An early symptom is shortness of breath when you are active. This shortness of breath may seem normal to you.
Symptoms later in the disease may include:
Call your doctor if your symptoms get worse or you have new symptoms.
How is mitral valve stenosis diagnosed?
Mitral valve stenosis may not be diagnosed until you've had the disease for some time. If you don't have symptoms, the first clue might be a heart murmur your doctor hears during a routine checkup.
Your doctor will ask you questions about your past health and do a physical exam. If your doctor thinks you might have the disease, he or she may do more tests. These may include:
These tests also help your doctor find what caused the stenosis and how severe it is.
How is it treated?
Treatment depends on how severe the disease and your symptoms are.
You will likely need regular echocardiograms so your doctor can check for any changes in your mitral valve and heart.
If your stenosis is mild, you'll probably be able to do your usual activities, get mild exercise, and play some sports. But if your stenosis is moderate or severe, you may need to avoid intense exercise. But your doctor can help you choose an activity or exercise that is safe for you.
You may need to limit sodium in your diet.
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Frequently Asked Questions
Nearly all cases of mitral valve stenosis are caused by rheumatic fever, which can follow an untreated strep throat infection. But many people who have mitral valve stenosis don't realize that they had rheumatic fever.
Other less common causes include:
Although mitral valve stenosis is a lifelong disease, symptoms usually take 10 to 20 years to develop and can take as long as 40 years. After you develop symptoms, they may not become severe for up to 10 years. 1
Early symptoms are often mild. In the later stages, the left atrium may become damaged, causing more severe symptoms.
Symptoms of mitral valve stenosis include:
Other less common symptoms include:
You may not have any symptoms unless you exercise, are stressed, are pregnant, or have an infection or an irregular heartbeat. Or you may have only a few symptoms, no matter how bad your stenosis is.
What Increases Your Risk
Risk factors for mitral valve stenosis are:
When to Call a Doctor
Call 911 or other emergency services immediately if you have:
Call a doctor immediately if you have:
Who to see
Health professionals who can evaluate symptoms and order further tests as needed include:
A cardiovascular surgeon may do surgical repair or replacement of heart valves.
Exams and Tests
Mitral valve stenosis often has no symptoms in its early stages. It may not be diagnosed until you've had the disease for some time. One or more complications may lead to its diagnosis.
The first sign of mitral valve stenosis could be a heart murmur that your doctor hears during a routine checkup.
A review of your medical history and a physical exam can help your doctor find out if you have mitral valve stenosis. Your doctor also can use them to plan your treatment.
Your doctor will ask about your lifestyle, activity level, and family health history . Your doctor will want to know about your symptoms. He or she will ask if you have ever had:
During the physical exam, the doctor will:
An echocardiogram is used to find out if you have mitral valve stenosis and to see how bad it is. Your doctor can check your heart valve and take pictures of your heart.
In transesophageal echocardiography , a device is inserted down your throat and into your esophagus to make pictures of your heart. This may be done if your doctor wants to see a different view of your heart.
You will likely have regular echocardiograms so your doctor can keep track of any changes in your condition. Your doctor may recommend an echocardiogram every year if you have severe stenosis, every 1 to 2 years if you have moderate stenosis, or every 3 to 5 years if you have mild stenosis. 1
Electrocardiogram is used to measure the electrical activity in the heart. Small metal discs called electrodes are attached to your chest, arms, and legs. The electrodes are connected to a machine that translates the electrical activity into line tracings on paper. Your doctor looks at the tracings to check for problems.
A chest X-ray may show evidence of mitral valve stenosis. The test may show enlargement of the upper left heart chamber (left atrium) or the pulmonary arteries . Calcium deposits on the heart valves sometimes may be seen, especially if the buildup is severe.
Cardiac catheterization is usually done before any surgery for mitral valve stenosis to evaluate your heart, the degree of stenosis, and the health of your coronary arteries. Knowing the condition of the coronary arteries may affect later treatment decisions for stenosis.
Treatment of mitral valve stenosis depends on how bad your symptoms are.
Stenosis without symptoms
If you don't yet have symptoms or you have mild, stable symptoms, your doctor may only watch your condition with regular echocardiograms . Your doctor will want you to call if you notice symptoms or if you have a change in symptoms you already have.
Stenosis with symptoms
If you develop symptoms, your doctor may prescribe medicine that lowers your blood pressure and reduces fluid buildup. For more information, see Medications.
Repair or replace the mitral valve
If your stenosis gets worse, your doctor might suggest repairing or replacing your mitral valve.
Repairing the valve can be done by:
Mitral valve replacement surgery replaces the damaged valve with a new valve.
For more information, see Surgery.
Mitral valve stenosis can be an easy condition to overlook in its mild form. But as it gets worse, it often has serious complications. These are serious problems that need treatment.
The most common complications are:
Other complications include:
Living With Mitral Valve Stenosis
Long-term mitral valve stenosis can cause serious heart damage. But you can help yourself live fully by working with your doctor and having a healthy lifestyle.
Talk to your doctor about how often you need to be examined. You will likely have regular echocardiograms so your doctor can keep track of any changes in your condition. How often you get the test depends on how bad your stenosis is.
Call your doctor if your symptoms get worse or you have new symptoms. For more information, see When to Call a Doctor.
Exercise with care
Ask your doctor what level of exercise is safe for you. Exercise helps keep your heart and body healthy. But when you have mitral valve stenosis, exercise can put extra strain on your heart and cause symptoms like fluid buildup in your lungs. So exercise with care and be aware of any symptoms like shortness of breath. If you don't exercise, talk to your doctor before you start.
If your stenosis is mild and you don't have symptoms, your doctor may encourage you to do low-level aerobic exercise.
If your stenosis is moderate or severe and you have symptoms, you should avoid strenuous activity. You may be able to do low-level activities to help keep your heart healthy.
People who have severe stenosis may need to be cautious about their level of physical activity. You may be able to do certain types of exercise that won't strain your heart.
Limit your sodium
Depending on how bad your symptoms are, your doctor may advise you to limit sodium . If you consume too much sodium, it will cause your body to retain excess fluid. Excess fluid in the body will cause swelling, trouble breathing, fatigue, and other side effects.
Cutting back on sodium usually includes avoiding foods such as potato chips, pretzels, processed meats and cheeses, canned soups, and fast foods.
When you shop for groceries, check labels carefully for hidden sodium.
Medicines are often used to relieve the symptoms and prevent complications of mitral valve stenosis. Usually they are also prescribed after surgery to repair or replace the valve.
Diuretics ("water pills") reduce fluid buildup and related swelling. They may also lower blood pressure in the upper left heart chamber (left atrium) and relieve breathing problems.
Medicines used to treat complications include:
You may need surgery to repair or replace your mitral valve if medicines don't control your symptoms or if your doctor thinks that you need more treatment.
Deciding whether you need surgery and if so, when, depends on the severity of your disease, the possibility that it will get worse, and the risks of surgery.
For more information about the decision to repair or replace a mitral valve, see Mitral Valve Stenosis: Repair or Replace the Valve?
You may have one of the following procedures to repair the valve:
Mitral valve replacement surgery might be done if the valve is damaged beyond repair. This surgery is typically an open-heart surgery using a heart-lung bypass machine.
If you have valve replacement surgery, a mechanical or tissue valve will be used to replace your heart valve. Before you have surgery, you and your doctor will decide which type of valve is right for you. To help with this decision, see:
Other Places To Get Help
Last Revised: November 18, 2011
Bonow RO, et al. (2008). 2008 Focused update incorporated into the ACC/AHA 2006 Guidelines for the management of patients with valvular heart disease: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing committee to revise the 1998 Guidelines for the management of patients with valvular heart disease). Circulation, 118(15): e523–e661.
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