The most common heart valve abnormality is called Mitral Valve Prolapse (MVP), which affects between 5 percent and 20 percent of the population. It is more commonly found in women than men and can go undetected for years, as symptoms usually do not occur until adolescence or even adulthood. MVP is most commonly diagnosed among patients between the ages of 20 and 40.
What is it?
MVP is a condition of the mitral valve, a two-flapped heart valve between the left atrium and left ventricle. In MVP, one or both of the valve flaps are too large, and the mitral valve does not close evenly with each heartbeat. Because of this imperfect closing, the valve itself slightly balloons back into the left atrium, sometimes causing what is known as a "click." With the flap there may sometimes be a slight backward leaking of blood (regurgitation) as well, resulting in a heart murmur.
MVP seems to be an inherited disorder, although the precise genes are not known. If proper precautions are taken (see below) it will not affect life expectancy, and generally has no impact on normal activities.
What are the symptoms?
Approximately 60 percent of individuals with MVP never exhibit any symptoms. Generally, a stressful situation (childbirth, change in job situation, viral illness) brings on symptoms that ordinarily would not be present. Some of these symptoms include:
- Irregular heartbeat or palpitations, particularly when lying on the left side.
Tachycardia, increased heartbeats or pounding of the chest, often after exertion.
Nonspecific chest pain lasting from a few seconds to several hours, occurring at rest rather than during exertion.
Panic attack, a sudden feeling of anxiety or doom.
Fatigue and weakness, even after slight exertion (including minor housework); sometimes misdiagnosed as chronic fatigue syndrome.
Migraine headaches, resulting from abnormal nervous system control of blood flow.
As noted above, many people with MVP never exhibit any of the above symptoms. The condition can be detected during a routine checkup with a simple stethoscope. After the ventricle begins to contract, a clicking sound can be heard - the sound of the abnormal valve fighting the pressure of the left ventricle. The diagnosis can be confirmed with an echocardiogram or cardiac echo; the echocardiogram also can determine the level of severity of the prolapse and the degree of regurgitation.
Most patients can be monitored simply, with a follow-up checkup every few years. Patients with pronounced regurgitation problems (blood leaking backward) may be monitored more closely.
What are the risks and problems associated with MVP?
Just as many MVP patients exhibit no symptoms, very few patients ever experience any complications arising from this syndrome. Rare complications include chest pain (angina pectoris) and irregular heart beat (arrhythmia), both of which can be treated with medication. Another rare complication involves formation of blood clots on the valve, making an MVP patient vulnerable to strokes; this problem requires treatment with an anticoagulant (blood thinner) medication.
The most common and serious MVP-related problem, endocarditis, involves bacterial infection of the mitral valve. Although it can be fatal if left untreated, endocarditis can be easily prevented. MVP patients are most commonly vulnerable to introduction of bacteria into the bloodstream (and endocarditis) when they are undergoing certain medical procedures, particularly dental work or minor surgery. Because of this, patients should inform their doctor or dentist that they have MVP, and be given antibiotic prophylaxis (preventive treatment) before the procedure.
When does a patient require antibiotics?
The American Heart Association (AHA) has issued recommendations for surgical and dental treatments in patients who have MVP and other heart disorders. The use of antibiotics is important for preventing bacterial endocarditis, a rare but potentially fatal infection that causes inflammation of the heart's valves, or its inner lining. The use of antibiotics for individuals who have MVP has been somewhat controversial.
The AHA guidelines suggest that for many procedures, most MVP patients do not need antibiotics; antibiotics are only required for those individuals who have valve leakage (mitral regurgitation) either detected as a heart murmur or through an ultrasound, or people with greatly thickened valve tissues.
The rare exception
Although most MVP patients do very well with the treatments and preventive measures outlined above, there is sometimes need for heart surgery to either repair or replace the mitral valve. This occurs only among patients who experience severe mitral regurgitation, which can result in progressive heart enlargement, and ultimately, heart failure.
Surgeons are more likely to perform corrective surgery rather than replace the valve with an artificial one, mainly because the introduction of an artificial valve requires lifelong use of blood thinners to prevent clotting. If a patient is found to have regurgitation problems, surgery is recommended and performed at as young an age as possible, reducing the risk of further damage to the heart.
What is Mitral Valve Prolapse?, National Society for Mitral Valve Prolapse and Dysautonomia.