MITRAL VALVE REGURGITATION

Mitral valve prolapse is a common cause of a heart murmur caused by a “leaky” heart valve. Most cases of mitral valve prolapse are not serious and only need to be monitored.

Mitral valve prolapse is associated with many other symptoms and conditions. But experts aren’t sure that mitral valve prolapse is what causes them.

The mitral valve is a valve that lets blood flow from one chamber of the heart, the left atrium, to another called the left ventricle. In mitral valve prolapse, part of the mitral valve slips backward loosely into the chamber called the left atrium. This happens when the main heart muscle, called the left ventricle, squeezes during each heartbeat. Mitral valve prolapse differs from mitral valve stenosis. In mitral valve stenosis, the mitral valve is stiff and constricted.

In mitral valve prolapse, the valve slips backward due to the abnormal size of or damage to the mitral valve tissues. For most people with mitral valve prolapse, the cause is unknown.

Mitral valve prolapse can run in families. It can also be caused by conditions in which cartilage is abnormal (connective tissue disease). Nearly 8 million people in the U.S. have mitral valve prolapse.

Symptoms of Mitral Valve Prolapse

Most people with mitral valve prolapse have no symptoms. They also never experience any health problems due to mitral valve prolapse.

Chest pain is the most frequent symptom in people who have symptoms with mitral valve prolapse. The chest pain may be very bothersome and frightening, but it does not increase the risk of heart attack, death, or other heart problems.

Mitral valve prolapse is the most common cause of mitral regurgitation. That’s a condition in which some blood flows backward through the mitral valve with each heartbeat. Over years, moderate or severe mitral regurgitation can cause weakness of the heart muscle, known as congestive heart failure. Symptoms of congestive heart failure include:

• Shortness of breath with exertion

• Swelling in the legs and feet

• A racing or irregular heartbeat (arrhythmia)

• Dizziness or light headedness

• Difficulty breathing or shortness of breath, often when lying flat or during physical activity

• Fatigue

• Chest pain that’s not caused by a heart attack or coronary artery disease

WHEN TO SEE A PHYSICIAN

If you think you have any of the above symptoms, make an appointment with your physician.

Many other conditions cause the same symptoms as mitral valve prolapse, so only a visit to your physician can determine the cause of your symptoms. If you’re having chest pain and you’re unsure if it could be a heart attack, seek emergency care immediately.

If you’ve already been diagnosed with mitral valve prolapse, see your physician if your symptoms worsen.

Causes

When your heart is working properly, the mitral valve closes completely during contraction of the left ventricle and prevents blood from flowing back into your heart’s upper left chamber (left atrium).

But in some people with mitral valve prolapse, one or both of the mitral valve’s flaps (leaflets) have extra tissue bulging (prolapsing) like a parachute into the left atrium each time the heart contracts.

The bulging may keep the valve from closing tightly. When blood leaks backward through the valve, it’s called mitral valve regurgitation.

This may not cause problems if only a small amount of blood leaks back into the atrium. More-severe mitral valve regurgitation can cause symptoms such as shortness of breath, fatigue or lightheartedness.

Another name for mitral valve prolapse is click-murmur syndrome. When a physician 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:

• Barlow’s syndrome

• Floppy valve syndrome

• Billowing mitral valve syndrome

• Myxomatous mitral valve disease

Risk factors

Mitral valve prolapse can develop in any person at any age.

Serious symptoms of mitral valve prolapse tend to occur most often in men older than 50.

Mitral valve prolapse can run in families and may be linked to several other conditions, such as:

• Marfan syndrome

• Ehlers-Danlos syndrome

• Ebstein’s anomaly

• Muscular dystrophy

• Graves’ disease

• Scoliosis

Complications

Although most people with mitral valve prolapse never have problems, complications can occur. They may include:

• Mitral valve regurgitation. The most common complication is a condition in which the valve leaks blood back into the left atrium (mitral valve regurgitation).

Being male or having high blood pressure increases your risk of mitral valve regurgitation.

If regurgitation is severe, you may need an operation to replace the valve in order to prevent heart failure.

• Heart rhythm problems (arrhythmias). Irregular heart rhythms most commonly occur in the upper chambers of the heart. They may be bothersome, but aren’t usually life-threatening.

People with severe mitral valve regurgitation or severe deformity of their mitral valve are most at risk of having rhythm problems, which can affect blood flow through the heart.

• Heart valve infection (endocarditis). The inside of your heart is lined by a thin membrane called the endocardium. Endocarditis is an infection of this inner lining.

An abnormal mitral valve increases your chance of getting endocarditis from bacteria, which can further damage the mitral valve.

People at high risk of endocarditis may be prescribed antibiotics before certain dental and clinical procedures, to reduce the risk of infection.

Diagnosis

Examination of the patient reveals characteristic findings unique to mitral valve prolapse. Using a stethoscope, a clicking sound is heard soon after the ventricle begins to contract. This clicking is felt to reflect tightening of the abnormal valve leaflets against the pressure load of the left ventricle. If there is associated leakage (regurgitation) of blood through the abnormal valve opening, a “whooshing” sound (murmur) can be heard immediately following the clicking sound.

Echocardiography (ultrasound imaging of the heart) is the most useful test for mitral valve prolapse. Echocardiography can measure the severity of prolapse and the degree of mitral regurgitation. It can also detect areas of infection on the abnormal valves. Valve infection is called endocarditis and is a very rare, but potentially serious complication of mitral valve prolapse. Echocardiography can also evaluate the effect of prolapse and regurgitation on the functioning of the muscles of the ventricles.

Abnormally rapid or irregular heart rhythms can occur in patients with mitral valve prolapse, causing palpitations. A 24-hour Holter monitor is a device that takes a continuous recording of the patient’s heart rhythm as the patient carries on his/her daily activities. Abnormal rhythms occurring during the test period are captured and analyzed at a later date. If abnormal rhythms do not occur every day, the Holter recording may fail to capture the abnormal rhythms. These patients then can be fitted with a small “event-recorder” to be worn for up to several weeks. When the patient senses a palpitation, an event button can be pressed to record the heart rhythm prior to, during, and after the palpitations.

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 dosage, if any, as directed.