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.
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.
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.
Mitral valve stenosis is a lifelong disease, but symptoms may not happen for many years. 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.
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.
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.
You can make lifestyle changes to keep your heart healthy. Your doctor may advise you to:
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 may not happen for many years.
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.
Risk factors for mitral valve stenosis are:
Call 911 or other emergency services immediately if you have:
Call a doctor now if you have:
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 6 to 12 months if you have severe stenosis or every 3 to 5 years if you have mild to moderate stenosis.footnote 1
A stress echocardiogram may be done to see how your heart responds to exercise.
Electrocardiogram is used to measure the electrical activity in the heart. Small pads or patches 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 is repair or replacement of the mitral valve.
Your doctor will check many things to see when treatment is right for you and what type of treatment is right for you. These things include the severity of stenosis, the shape of your mitral valve, and whether you have symptoms.
If your stenosis is mild or moderate, 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 the symptoms you already have. If your stenosis is severe, your doctor may recommend valve repair or replacement.
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:
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.
Medicines might be used to prevent or treat complications of mitral valve stenosis. Usually they are also prescribed after surgery to repair or replace the valve.
Medicines used to prevent and treat complications include:
You may need surgery to repair or replace your mitral valve.
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. Your doctor will check many things including your health, the shape of your mitral valve, and whether you have symptoms.
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:
- Nishimura RA, et al. (2014). 2014 AHA/ACC guideline 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. Circulation, published online March 3, 2014. DOI: 10.1161/CIR.0000000000000031. Accessed May 1, 2014.
Current as of: January 10, 2022
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