Mitral valve prolapse

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Mitral valve prolapse


Definition


Mitral valve prolapse (MVP) is a common heart disorder. It occurs when the valve between your heart's left upper chamber (left atrium) and the left lower chamber (left ventricle) doesn't close properly. When the left ventricle contracts, the valve's leaflets bulge (prolapse) upward or back into the atrium. Mitral valve prolapse sometimes leads to blood leaking backward into the left atrium, a condition called mitral valve regurgitation.
Mitral valve prolapse affects slightly more than 2 percent of adults in the United States. Men and women appear to develop MVP in similar numbers.
In most people, mitral valve prolapse is harmless and doesn't require treatment or changes in lifestyle. It also doesn't shorten your life expectancy. In some people with mitral valve prolapse, however, the progression of the disease requires treatment.

Symptoms


Although mitral valve prolapse is a lifelong disorder, many people with this condition never have symptoms. When diagnosed, people may be surprised to learn that they have a heart abnormality.
When signs and symptoms do occur with mitral valve prolapse, it's typically because blood is leaking backward through the valve (regurgitation). Symptoms can vary widely from one person to another. They tend to be mild, develop gradually and may include:

Causes


The mitral valve separates the two chambers (atrium and ventricle) of the left side of the heart. In mitral valve prolapse, the leaflets of the mitral valve bulge (prolapse) into the left atrium like a parachute during the heart's contraction. Thus, some blood may leak back into the atrium from the ventricle.



When your heart is working properly, the mitral valve closes during contraction of the left ventricle to prevent blood from flowing back into your heart's upper left chamber (left atrium). But in some people with MVP, the mitral valve malfunctions. In these people, the mitral valve leaflets are abnormal with extra tissue, bulging (prolapsing) like a parachute into their left atrium each time the heart contracts. The bulging may keep the valve from closing tightly. This may not cause problems if only a small amount of blood leaks back into the atrium. When blood leaks backwards through the valve, it's called mitral regurgitation (MR). MR can cause symptoms.
Another name for mitral valve prolapse is click-murmur syndrome. When a doctor listens to your heart using a stethoscope, he or she may hear a clicking sound as the valve's leaflets billow out, followed by a murmur resulting from blood flowing back into the atrium. Other names to describe mitral valve prolapse include:[/b]

Mitral valve prolapse can be inherited, with the disorder frequently running in families. People with Marfan syndrome as well as those with connective tissue disorders have an increased risk of MVP. Other conditions that are sometimes linked to mitral valve prolapse include Ehlers-Danlos syndrome, adult polycystic kidney disease and Ebstein's anomaly.
If you have mitral valve prolapse, the flaps of your mitral valve may be oversized or thickened. People with MVP are often thin and have curvature of the spine (scoliosis) or they may have defects in the bones of their chest wall.

When to seek medical advice

If you develop what may appear to be symptoms of mitral valve prolapse, contact your doctor. Many other conditions cause the same symptoms as mitral valve prolapse, so only an examination by your doctor can confirm a diagnosis. If you've already been diagnosed with this disorder, see your doctor if your symptoms worsen.

Tests and diagnosis

Doctors may diagnose mitral valve prolapse at any age. Your doctor is most likely to detect mitral valve prolapse during a routine examination of your heart using a stethoscope. If mitral valve prolapse is present, he or she may hear abnormal sounds, such as a characteristic clicking noise that suggests mitral valve prolapse. If there's significant mitral regurgitation, then your doctor will also hear a heart murmur.
An echocardiogram is usually done to confirm the diagnosis. An echocardiogram is a noninvasive, ultrasound evaluation of your heart. This test uses high-frequency sound waves to create images of your heart and its structures, including the mitral valve itself and the flow of blood through it. The amount of leakage (regurgitation) can be measured.
In some cases, you may need to undergo additional tests to provide more details about your heart's valves and help in the diagnosis, including ruling out other conditions of the heart.
If you have mitral valve regurgitation but don't have symptoms, your doctor may suggest you return for examinations to monitor your condition every three to five years. The need for follow-up will be based on the details of your case, including the amount of leakage. If, however, you have severe regurgitation, your doctor may suggest surgery to repair your valve.

Complications



Although most people with mitral valve prolapse never have problems, complications can occur. Complications tend to occur in middle-aged or older adults. They may include:

Treatments and drugs

Most people with mitral valve prolapse, particularly people without symptoms, don't require treatment.
If you develop symptoms, your doctor might prescribe certain medications to treat MVP-related chest pain, heart rhythm abnormalities or other complications. Some medications you might be prescribed include:

Surgical treatment for mitral valve prolapse
Though most people with mitral valve prolapse don't need surgery, your doctor may suggest surgery if you have severe mitral valve regurgitation with or without symptoms. The risk of severe mitral regurgitation is enlargement of your heart's main pumping chamber (the left ventricle). This can eventually weaken your heart, preventing it from effectively pumping blood. If regurgitation goes on too long your heart may be too weak for surgery.
If your doctor suggests surgery, there are two main options, repair or replacement of the mitral valve.

Current guidelines from the American Heart Association indicate repairing, rather than replacing, your mitral valve is usually the best option for most people with MVP who need surgery. The success of mitral valve repair depends on the expertise of the surgeon. Valve repair or replacement operations are best done by surgeons experienced in doing them.
Mitral valve repair or replacement requires open heart surgery, done under general anesthesia. Through an incision, usually through your breastbone (sternum), your heart is exposed and connected to a heart-lung machine that assumes your breathing and blood circulation functions during the procedure. Your surgeon then replaces or repairs the valve. After the operation, you'll spend one or more days in an intensive care unit, where your heart function and general recovery are closely monitored. Less invasive ways of repairing or replacing the mitral valve are also being studied, but these procedures aren't widely available yet.
Depending on your age and risk factors for coronary artery disease, your doctor may recommend cardiac catheterization and coronary angiograms before surgery. During a cardiac catheterization, a long, thin, flexible plastic tube (catheter) is inserted into your body. Dye is injected into the blood vessels of your heart. The dye is visible by X-ray machine. The machine rapidly takes a series of X-ray images (angiograms), offering a detailed look at your heart arteries to determine if you need coronary artery bypass at the same time as your valve surgery. Pressures in the heart's chambers may be measured, particularly if there is any concern about high blood pressure in the lung arteries (pulmonary hypertension) that might influence the decision to proceed with surgery.
Antibiotics seldom recommended
Doctors used to recommend that some people with mitral valve prolapse take antibiotics before certain dental or medical procedures to prevent endocarditis, but not anymore. In 2007, the American Heart Association issued new guidelines saying, in part, antibiotics are no longer necessary in most cases for someone with mitral valve regurgitation or mitral valve prolapse.
This doesn't mean it's not important to take good care of your teeth through brushing and flossing. There is some concern that infections in your mouth from poor oral hygiene might increase the risk of germs entering your bloodstream. In addition to brushing and flossing, regular dental exams — at least yearly — are an important part of maintaining good oral health.
Still, if you've been told to take antibiotics before any procedures in the past, check with your doctor to see how these new recommendations apply to you.
Precautions during pregnancy
If you're pregnant and have mitral valve prolapse, your chances of a successful, uncomplicated pregnancy are good. Even so, doctors sometimes recommend antibiotics during childbirth if there's a risk of an infection that could affect the mitral valve.

Prevention

You can't prevent mitral valve prolapse. However, you can lower your chances of developing the complications associated with it by making sure you take your medications, if any, as directed. Also, remember to let your doctor or dentist know you have mitral valve prolapse so that they can evaluate whether you need antibiotics to help prevent infections of your heart valve.

Lifestyle and home remedies
Most people with mitral valve prolapse lead normal, productive and symptom-free lives. Doctors generally won't recommend restrictions on your lifestyle or any limitations on your personal exercise or dietary program.

By Mayo Clinic Staff
Jan. 24, 2008