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Mitral Valve Stenosis

  • Definition

    In mitral valve stenosis, the mitral valve leaflets are fused together by scar tissue, gradually narrowing the valve and slowing the flow of blood from the left atrium to the left ventricle.


    For blood to circulate effectively through the heart, each of four heart valves must be functioning properly. In mitral valve stenosis, the valve becomes stiff, and can no longer open and shut freely. It may also be leaky (mitral regurgitation or insufficiency), allowing some blood to flow backwards.

    To overcompensate for these problems, the heart is forced to work harder, which can enlarge and weaken it. An abnormally functioning valve also can lead to a heart infection or the formation of blood clots that can cause heart attack and strokes.


    rheumatic fever in childhood is by far the most common cause of mitral stenosis in adulthood. It can damage the heart valve and cause scarring, which results in problems later in life, usually in young adulthood.

    More rarely, mitral stenosis can occur from congenital heart disease or from calcium deposits that accumulate over years.


    Symptoms of mitral valve stenosis include shortness of breath with effort or when lying flat, exhaustion, and palpitations. Symptoms can be mild or severe.

    Some patients may be unaware of mitral valve stenosis until a physician detects the problem during a routine examination. Others are plagued by an increasing inability to perform normal activities. More often, symptoms first appear with exercise, stress or infection, all of which place extra stress on the heart.

    With time, if the condition deteriorates, symptoms worsen. A patient can also develop atrial fibrillation (an irregular heart beat).


    Diagnosis is based on the medical history including symptoms, existence of a characteristic murmur upon examination of the heart, and echocardiography (an ultrasound study of the heart valves and muscle).


    Treatment of mitral stenosis depends on factors that include the patient's symptoms, severity of the stenosis, and health of the patient.

    Surgical repair of mitral valve stenosis is called commissurotomy. This usually involves open heart surgery in which the surgeon tries to separate the fused leaflets either manually or with a surgical knife. In some cases, the valve may need to be replaced in another type of open heart surgery.

    Catheterization techniques can be used to widen heart valves that are stenotic (narrowed) and limit blood flow.

    Percutaneous balloon valvuloplasty (percutaneous means "through the skin" [with a catheter], valvulo means "related to the valve," plasty means "shaping"), is a procedure in which one or two balloons mounted on catheters are guided into the heart through blood vessels in the groin, positioned through the stenotic valve, and then inflated. This procedure enlarges the opening through the valve and improves blood flow.

    As with any heart catheterization procedure, there are potential risks, in addition to the increased chance of causing further damage to the valve structure with manipulation of the balloon. However, the hospital stay is usually shorter with valvuloplasty than with open-heart valve operations.

    Mitral balloon valvuloplasty may not be appropriate if there is too much calcium buildup on the valve or if it is already allowing blood to leak backward (mitral regurgitation). It is also not performed if there is a blood clot in one of the heart chambers, because of the risk of dislodging it. Under these circumstances, the valve must be replaced.


    What tests need to be done to diagnose the condition?

    What are the procedures of the tests and are there any risks or complications?

    What condition are the valves in?

    How serious is the condition?

    What are the chances of complications developing?

    Should a specialist be consulted?

    What treatment will you be recommending?

    Will you be prescribing any medication? What are the side effects?

    Will surgery at some point be necessary or helpful?

    How is the surgical procedure performed?

    How successful is the procedure?