Mitral valve prolapse is a heart problem in which the valve that separates the left upper and lower chambers of the heart does not close properly.

The heart's mitral valve helps blood on the left side of the heart flow in one direction. It closes to keep blood from moving backwards when the heart beats (contracts).

Mitral valve prolapse is the term used when the valve does not close properly. It can be caused by many different things. In most cases, it is harmless and patients usually do not know they have the problem. As much as 10% of the population has some minor, insignificant form of mitral valve prolapse, but it does not generally affect lifestyle.

In a small number of cases, the prolapse can cause blood to leak backwards. This is called mitral regurgitation. This needs to be treated with medication or surgery.

Mitral valves that are structurally abnormal can raise the risk for bacterial infection.

Some forms of mitral valve prolapse seem to be passed down through families (inherited). Mitral valve prolapse has been associated with Marfan syndrome (a disorder present from birth) and Graves disease.

Many people with mitral valve prolapse are thin women who may have minor chest wall deformities, scoliosis, or other disorders.

Some people with mitral valve prolapse may also have a hole in their heart called an atrial septal defect.

• Sensation of feeling the heart beat (palpitations)
• Chest pain (not caused by coronary artery disease or a heart attack)
• Hard to breath after activity
• Fatigue
• Cough
• Shortness of breath when lying flat (orthopnea)

The doctor will perform a physical exam and use a stethoscope to listen to your heart and lungs. The doctor may feel a thrill (vibration) over the heart, and hear a heart murmur ("mid-systolic click"). The murmur gets louder when you stand up.

Blood pressure is usually normal.

The following tests may be used to diagnose mitral valve prolapse pr a leaky mitral valve:

• Echocardiogram
• Color-flow Doppler examination
• Cardiac catheterization
• Chest x-ray
• ECG (may show arrhythmias such as atrial fibrillation)
• Chest MRI
• CT scan of the chest

Most of the time, there are no (or few) symptoms, and treatment is not needed.

If you have severe mitral valve prolapse, you may need to stay in the hospital. Surgery to repair or replace the valve may be needed if you have severe mitral regurgitation or your symptoms get worse.

Antibiotics are given if there is a bacterial infection or risk of one.

Other drugs that may be prescribed are listed below:

• Anti-arrhythmics drugs help control irregular heart beats.
• Vasodilators dilate (widen) blood vessels, which makes it easier for the heart to work.
• Digitalis is used to strengthen the heartbeat.
• Diuretics (water pills) help remove excess fluid in the lungs.
• Propranolol is given for palpitations or chest pain.
• Anticoagulants (blood thinners) help prevent blood clots in persons who also have atrial fibrillation.

Mitral valve prolapse should not adversely affect your lifestyle. If the leaky valve becomes severe, your outlook may be similar to mitral regurgitation from any other cause.

Most of the time, the condition is harmless and does not cause symptoms. Symptoms that do occur can be treated and controlled with medicine or surgery. However, some irregular heart beats (arrhythmias) associated with mitral valve prolapse can be deadly.

• Endocarditis -- valve infection
• Severe leaky mitral valve (regurgitation)
• Stroke
• Clots to other areas
• Irregular heart beats (arrhythmias), including atrial fibrillation

Call your health care provider if you have increasing amounts of chest discomfort, palpitations, or fainting spells. Also alert your health care provider if you have any long-term illnesses with fevers.

You can't usually prevent mitral valve prolapse, but you can prevent certain complications. Tell your health care providers, including your dentist, if you have a history of heart disease or heart valve problems.

American College of Cardiology/American Heart Association: 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). J Am Coll Cardiol. 2006; 48:1-148.

Salem DN, Stein PD, Al-Ahmad A, et al. Antithrombotic therapy in valvular heart disease -- native and prosthetic: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest. 2004 Sep;126(3 Suppl):457S-82S.

Karchmer AW. Infective Endocarditis. In: Libby P, Bonow RO, Mann DL, Zipes DP, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine, 8th ed. St. Louis, Mo: WB Saunders; 2007: chap. 63.