About mitral valve prolapse
What is mitral valve prolapse?
What is mitral valve prolapse?
Mitral valve prolapse (also known as "click murmur syndrome" and "Barlow's syndrome") is the most common heart valve abnormality. The condition is slightly more prevalent in women than in men. The mitral valve is one of the four heart valves. A normal mitral valve consists of two thin leaflets, located between the left atrium and the left ventricle of the heart. Mitral valve leaflets, shaped like parachutes, are attached to the inner wall of the left ventricle by a series of strings called "chordae." When the ventricles contract, the mitral valve leaflets close snugly and prevent the backflow of blood from the left ventricle into the left atrium. When the ventricles relax, the valves open to allow oxygenated blood from the lungs to fill the left ventricle.
In patients with mitral valve prolapse, the mitral apparatus (valve leaflets and chordae) becomes affected by a process called myxomatous degeneration. In myxomatous degeneration, the structural protein collagen forms abnormally and causes thickening, enlargement, and redundancy of the leaflets and chordae. Blood normally flows through the mitral valve from the left upper chamber (left atrium) to the left lower chamber (left ventricle) of the heart. When the ventricles contract, the redundant leaflets prolapse (flop backwards) into the left atrium, sometimes allowing leakage of blood through the valve opening (mitral regurgitation) back into the left atrium. When severe, mitral regurgitation can lead to heart failure and abnormal heart rhythms. Most patients are totally unaware of the prolapsing of the mitral valve. Others may experience a number of symptoms discussed below.
The mitral valve prolapse (MVP) syndrome has a strong hereditary tendency, although the exact cause is unknown. Affected family members are often tall, thin, with long arms and fingers, and straight backs. It is seen most commonly in women from 20 to 40 years old, but also occurs in men.
What are the symptoms for mitral valve prolapse?
Although mitral valve prolapse is usually a lifelong disorder, many people with this condition never have symptoms. When diagnosed, people may be surprised to learn that they have a heart condition.
When signs and symptoms do occur, it may be because blood is leaking backward through the valve (regurgitation). Mitral valve prolapse symptoms can vary widely from one person to another. They tend to be mild and develop gradually. Symptoms may include:
- A racing or Irregular heartbeat (arrhythmia)
- Dizziness or Lightheadedness
- 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 doctor
If you think you have any of the above symptoms, make an appointment with your doctor.
Many other conditions cause the same symptoms as mitral valve prolapse, so only a visit to your doctor 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 medical care immediately.
If you've already been diagnosed with mitral valve prolapse, see your doctor if your symptoms worsen.
What are the causes for mitral valve prolapse?
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 lightheadedness.
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:
- Barlow's syndrome
- Floppy valve syndrome
- Billowing mitral valve syndrome
- Myxomatous mitral valve disease
What are the treatments for mitral valve prolapse?
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.
What are the risk factors for mitral valve prolapse?
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