Mitral Valve Prolapse

Mitral Valve Prolapse Overview

Mitral valve prolapse (MVP) is also called click-murmur syndrome, floppy mitral valve syndrome, and Barlow syndrome after the doctor who first described MVP.

The mitral valve is one of 4 valves in the heart. It opens and closes to control blood flow between the heart's left atrium and the left ventricle. The mitral valve has 2 flaps, or "leaflets."

In mitral valve prolapse, one or both leaflets of the valve are too large, or the chordae tendinea (the strings attached to the underside of the leaflets, connected to the ventricular wall) are too long (redundant), resulting in uneven closure of the valve during each heartbeat. Because of uneven closure of the leaflets, the valve bulges back, or "prolapses," into the left atrium like a parachute. When this happens, a very small amount of blood may leak through, moving backward from the ventricle to the atrium.

The valve still works well, and the heart pumps normally. Prolapse does not cause damage to the heart over time. Only 2% of people have other structural heart problems along with mitral valve prolapse.

Previously called the most common heart valve abnormality, mitral valve prolapse was thought to have affected 5-20% of the general population, mainly women. Now with newer, wiser echocardiographic criteria, it is thought to affect only 2-3% of the general population, and it is most often diagnosed in people aged 20-40 years.

Mitral Valve Prolapse Causes

For most people, the cause for mitral valve prolapse is unknown.

  • Some people may inherit the condition, especially those associated withconnective tissue disorders like Marfan's syndrome. Marfan's syndrome is an inherited disorder of connective tissue that causes abnormally long limbs, loose joints, and bulges (aneurysms) in the aorta, the main artery from the heart. 
  • Up to 40% of people have dysautonomia, an imbalance of the autonomic nervous system. This is the part of the nervous system that controlsinvoluntary body functions such as breathing and the beating of the heart. This may lead to a large number of symptoms that seem serious to the person with the symptoms but are usually not serious (that is, they are not heart conditions).
Mitral Valve Prolapse Symptoms

About 60% of people with mitral valve prolapse have no symptoms. A stressful situation, such as childbirth, job change, or viral illness, can bring on symptoms that may include the following:

  • Irregular heartbeat or palpitations, especially while lying on the left side 
  • Chest pain - Sharp, dull, or pressing, lasting from a few seconds to several hours, usually not related to myocardialischemia (that is, not a threatened heart attack
  • Fatigue and weakness, even after little exertion 
  • Dizziness 
  • Light-headedness when rising from a chair or a bed 
  • Shortness of breath 
  • Low energy level, often misdiagnosed aschronic fatigue syndrome

The numerous symptoms of dysautonomia include the following:

People will also have symptoms related to associated illnesses, such as Marfan's syndrome or hyperthyroidism (increased thyroid hormone).

 

When to Seek Medical Care

Call the health care provider if symptoms persist or are recurrent, such as chest pains that come and go, palpitations, or light-headedness.

Once mitral valve prolapse has been diagnosed, call the health care provider if symptoms worsen or do not go away or if symptoms ofcongestive heart failure such as leg swelling or shortness of breath occur. This means the mitral valve is seriously leaking backward into the left atrium (mitral insufficiency).

People who have heart murmurs should consult a health care provider regarding use ofantibiotics to prevent heart valve infection during minor surgical procedures or dental work.

Women who think they are pregnant must call their health care providers.

Go to a hospital emergency department if any of the following occur:

  • Symptoms of heart failure suddenly worsen. 
  • Symptoms include evidence of a heart rhythm disorder, such as dizziness, blackout, or fainting spell, or a continuing and uncomfortable feeling that the heart is fluttering or racing. 
  • Chest pain does not go away.

 

 

Exams and Tests

If typical symptoms of mitral valve prolapse are present, the primary care provider or an emergency department physician will suspect a heart problem.

  • The health care provider will ask questions about symptoms, overall medical condition, lifestyle, and medications. 
  • The physical examination may or may not reveal signs that suggest mitral valve prolapse, such as a "click" with each heartbeat or a heart murmur that can be heard when the health care provider listens to the chest while a person is in multiple positions. The midsystolic click and latesystolic murmur are very position- and heart volume -dependent, so they are possible to miss if the person is only examined when lying face upward.
Diagnostic tests help rule out serious heart disease by evaluating how the heart is pumping and how well the valves are working. These tests are noninvasive, painless, and quick. The following tests are most common: 

  • Electrocardiogram (ECG): ECG records the rhythm and the electrical activity of the heart from a variety of angles. This information is very helpful in diagnosing a variety of heart problems, such as cardiac arrhythmias, heart attack, or thickening of the heart muscle
  • Echocardiogram (ECHO): ECHO uses sound waves (ultrasound) to provide a moving picture of the heart on a video screen. ECHO shows the motion of all the cardiac valves and whether the mitral valve flops backward when it closes. ECHO is usually sufficient to establish a diagnosis of mitral valve prolapse, but in some cases, it can miss the condition. The echo will also quantitate the degree of abnormality, including any significant leaky mitral valve or mitral insufficiency. If associated conditions are present, like Marfan's syndrome, these will also be diagnosed or excluded. 
  • Ambulatory ECG: A device called a Holter monitor records heart rhythms and electrical activity over an extended period, usually 24 hours. The person has this device attached to his chest while going about his usual activities. A diary of the person's activities are kept during the recording period so any abnormalities seen on the ECG can be linked with what the person was doing and feeling at the time. This test may be recommended if the person is having dizziness, light-headedness, fainting spells, or palpitations.
  • Stress ECG: This test is similar to a regular ECG except it shows the heart's response to stress, usually exercise. With ECG electrodes attached, the person walks on a treadmill or rides a stationary bike. Most people with symptoms, especially chest pain or signs of rhythm disturbances, should undergo the stress test since most patients have benign results that can be very reassuring.

 

Mitral Valve Prolapse Treatment

Mitral valve prolapse usually requires no specific treatment, except reassurance, since most people do not have serious underlying heart disease. Rather, care focuses on minor changes a person can make that may prevent symptoms.

  • The condition usually requires no activity restrictions, but the person should avoid competitive sports if he has a definite click and murmur of significant mitral insufficiency. Most people have minimal, if any, mitral insufficiency. 
  • There are no special restrictions on diet. 
  • Caffeine, alcohol, and stimulant intake should be limited if heart irregularities are present. 
  • Maintain normal fluid intake. Dehydrationcan provoke MVP.

If a woman is pregnant, she should tell herobstetrician or midwife that she has mitral valve prolapse.

  • Most women with mitral valve prolapse require no specific precautions. 
  • A woman may require antibiotics if she needs a urinary catheter or has an infection at the time of delivery and has a heart murmur of mitral insufficiency.

 

Medical Treatment

Usually a person needs no medications for mitral valve prolapse, just a strong dose of reassurance.

  • If a person has unusual heart rhythms, such as palpitations, she may need treatment with beta-blockers. 
  • To help prevent a heart valve infection, a person may need preventive antibiotics before certain dental or surgical procedures if she has a murmur of mitral insufficiency.

 

Surgery

On rare occasions, worsening valve leakage or extreme prolapse may require surgery to repair the valve. Improvements in heart surgery in the past 10 years have shown less need for mitral valve replacement with an artificial valve. 

 

Next Steps Follow-up

A person with mitral valve prolapse should see a health care provider for a follow-up exam every 2-3 years, including a clinical evaluation and possibly an ECHO test to assess whether blood leakage is worsening. 

 

Outlook

Mitral valve prolapse is usually a harmless disorder that does not lead to a heart attack and does not prevent a person from having a normal, active life. The condition does triggersome possible complications, but overall risk for them is very low. These complications include the following:

  • Cardiac arrhythmias: These are usually only benign premature beats that need no drug treatment. Occasionally, they can have sustained supraventricular tachycardianeeding further, more definitive, medicaltherapy. Sudden cardiac arrest due to aventricular tachycardia, which is life threatening, is very rarely reported. 
  • Worsening mitral regurgitation/insufficiency (backward blood flow) from either worsening prolapse or rupture of a heart muscle or tendon 
  • Congestive heart failure, due to the mitral regurgitation 
  • Stroke from a blood clot reaching the brainfrom the heart 
  • Inflammation of inner portions of the heart valves, called endocarditis

 

 

Multimedia

Media file 1: An ECG is obtained from a woman with mitral valve prolapse.
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Media type: Photo

Media file 2: A 2-dimensional ECG showing the rear mitral valve leaflet sinking into the left atrium.
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Media type: ECG

Media file 3: A 2-dimensional ECG viewed parallel to the sternum shows the rear mitral valve leaflet bulging back into the left atrium during a heart contraction.
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Media type: ECG

Media file 4: A 2-dimensional ECG in short axis view showing the rear mitral leaflet sinking back.
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Media type: ECG

 

Synonyms and Keywords

Barlow syndrome, Barlow's syndrome, click-murmur syndrome, dysautonomia, floppy mitral valve syndrome, heart valve disorder, mitral valve prolapse, MVP, heart valve abnormality, left atrium, left ventricle, heart valve, irregular heartbeat, palpitations, chest pain, congestive heart failure, heart valve infection, heart rhythm disorder, electrocardiogram, ECG, echocardiogram, ECHO, echo

 

Medical Treatment

Usually a person needs no medications for mitral valve prolapse, just a strong dose of reassurance.

  • If a person has unusual heart rhythms, such as palpitations, she may need treatment with beta-blockers. 
  • To help prevent a heart valve infection, a person may need preventive antibiotics before certain dental or surgical procedures if she has a murmur of mitral insufficiency
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