Mitral valve regurgitation (MR) develops when the mitral
valve (also called the atrioventricular valve) fails to close properly and
blood leaks back into the upper pumping chamber (left atrium). Although mild
cases of MR result in few problems, more severe and chronic cases eventually
weaken the heart and can result in
heart failure.
Medical therapy can delay
or minimize MR, but in some cases surgery is needed to replace the mitral
valve. Few people with
mitral valve prolapse (MVP) develop MR, and the
majority of MR cases that result from MVP are considered mild.
Symptoms of mitral valve regurgitation include:
- Fatigue or weakness.
- Shortness of
breath at rest or with exertion.
- Trouble breathing at
night.
- Fainting or blacking out.
- Fluid buildup in the
legs and feet (edema).
- Lightheadedness.
- Irregular
heart rhythms (such as
atrial fibrillation).
- A cough, possibly
producing white or pink mucus.
Rare complications of mitral valve regurgitation caused by
MVP include:
- Bacterial infection of the lining of the heart
(bacterial
endocarditis).
- Irregular or rapid heart
rhythms (arrhythmias).
- The formation of small blood clots (emboli)
that travel to the brain, where they may cause minor temporary interruption of
blood flow to an area of the brain (transient ischemic attack, or TIA) or a
stroke.
Some related problems may include:
- Atrial fibrillation, as the left upper
heart chamber (left atrium) enlarges.
- Heart failure, if mitral valve regurgitation is
moderate to severe. This can develop because the lower left heart chamber (left
ventricle) does not function properly.
- High blood pressure in the
lungs (pulmonary hypertension).
MR may also occur with mitral valve stenosis, a condition
that develops when the mitral valve fails to open as wide as it should.
There is also a slightly increased chance of sudden death in people with
MVP, although why this happens is not clear. It rarely occurs and is likely to
be caused by arrhythmias.