Mitral valve prolapse is an abnormal bulging of the mitral valve when the heart contracts (squeezes).
The mitral valve is 1 of 4 valves in the heart. It is located between the upper left heart chamber (left atrium) and lower left heart chamber (left ventricle). The mitral valve has 2 flaps, called leaflets, which open and close like a door with each heartbeat and normally let blood flow in just 1 direction through the heart.
If one or both of the leaflets bulge backwards into the atrium, the valve may not always close completely. When it does not close all the way, the valve may sometimes leak, letting small amounts of blood flow backward in your heart.
A defect in the mitral valve can cause the bulging and keep the leaflets from closing well, but often it is not known why or how the prolapse occurs. Many people have mitral valve prolapse, but it is usually mild and causes no problems. It is common in adults with otherwise normal hearts. It also occurs in people with rare, inherited diseases of connective tissue, such as Marfan syndrome or Ehlers-Danlos syndrome. Their skin and other body tissues are abnormally elastic.
Most people have no symptoms. However, sometimes you may have brief periods of a rapid heartbeat or skipped beats (arrhythmia). You may especially notice these changes in your heart rhythm when you are physically active, for example, exercising. If you have these symptoms, tell your healthcare provider.
Often mitral valve prolapse is discovered during a routine physical exam, when your healthcare provider listens to your heart with a stethoscope. When your heart muscle contracts, stretched valve leaflets create a "click" sound that your healthcare provider can hear. If the valve leaks, your provider can hear a murmur. Your provider may ask you to stand, sit, lie down, or squat during your exam so he or she can better hear the faint sounds.
An echocardiogram, which is an ultrasound of the heart, is the best way to diagnose mitral valve prolapse. The picture made by the sound waves shows the prolapse, any thickening of the valve leaflets, and any leakage of blood through the prolapsed valve. An echocardiogram can show if you have badly thickened and stretched valve leaflets, which may mean you have a higher risk of serious problems.
Most people with mitral valve prolapse don't need treatment because the prolapse is not causing any serious problems.
Some people feel discomfort from changes in their heart rhythm. Drugs such as beta blockers may be helpful.
In rare cases of severe mitral valve prolapse, the valve may leak more and more over time. Your healthcare provider will keep checking your heart with echocardiograms and may give you medicine if your heart rate is fast or irregular. In very rare cases it may be necessary to have surgery to repair the mitral valve.
You may keep feeling these abnormal heart rhythms from time to time. However, most of these arrhythmias are not harmful or life threatening.
Rarely, leakage caused by the prolapse is severe enough to cause more serious heart problems. More blood may leak backward through the valve. This leakage is called mitral regurgitation. It usually gets worse with time and is more common in men with mitral valve prolapse and in people with high blood pressure. The leakage may become bad enough to require heart valve replacement surgery, but this is unusual. If you have mitral valve prolapse with significant mitral regurgitation, you have a slightly higher risk of stroke.
