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Mitral Valve Stenosis - Overview


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 camera.gif.

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 camera.gif.

See a picture of a normal mitral valve camera.gif.

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?

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:

  • Shortness of breath even when you have not been very active or when you are resting.
  • Feeling very tired or weak.
  • Pounding of the heart (palpitations).

Call your doctor if your symptoms get worse or you have new symptoms.

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