What is mitral valve prolapse (MVP)?

Mitral valve prolapse occurs when two mitral valve leaflets do not come together properly. When the two leaflets don’t come together and meet, blood then leaks backwards. This leak can be mild but can progress to severe leakage, at which point it may need to be fixed. Mitral valve prolapse that is mild is common, particularly in young or middle-aged women, but only becomes severe leakage in a small percentage of people.
Mitral (MI-tral) valve prolapse (MVP) is a condition in which one of the heart's valves, the mitral valve, doesn't work properly. The flaps of the valve are "floppy" and don't close tightly.
Much of the time, MVP doesn't cause any problems. Rarely, blood can leak the wrong way through the floppy valve, which may cause shortness of breath, palpitations (strong or rapid heartbeats), chest pain, and other symptoms.
In MVP, when the left ventricle contracts, one or both flaps of the mitral valve flop or bulge back (prolapse) into the left atrium. This can prevent the valve from forming a tight seal.
As a result, blood may flow backward from the ventricle into the atrium. The backflow of blood is called regurgitation (re-GUR-ji-TA-shun).
Backflow doesn't occur in all cases of MVP. In fact, most people who have MVP don't have backflow and never have any symptoms or complications. In these people, even though the valve flaps prolapse, the valve still can form a tight seal.
When backflow does occur, it can cause symptoms and complications such as shortness of breath, arrhythmias (ah-RITH-me-ahs), or chest pain. Arrhythmias are problems with the rate or rhythm of the heartbeat.
This answer from the National Heart, Lung and Blood Institute has been reviewed and/or edited by Dr. William D. Knopf.
My image of mitral valve prolapse (MVP) is analogous to an umbrella with redundant cloth. It creates floppiness. MVP occurs in approximately ten percent of the world population and is usually benign. The non-redundant covered valve opens then closes with a watertight seal with no leak or backwash of blood into the left atrial chamber. In MVP the redundant covering causes the valve to billow backwards and thus often clicks and breaks the water seal, causing the mitral regurgitation leak that is heard as a blood flow noise called a murmur. MVP is detectable on physical exam and by echocardiogram, a cardiac ultrasound procedure. Fewer than 25 percent of patients with MVP at any given time experience symptoms. Symptoms may include atypical chest pain that is often non-cardiac, shortness of breath and palpitations.
Mitral valve prolapse is one of the most common valvular abnormalities that affects our heart. The mitral valve is actually made up of two leaflets – think of them as flaps – of tissue.  These leaflets, or valves, sit between the left atrium and the left ventricle.  The left atrium is the chamber that receives oxygenated blood back from our lungs and the left ventricle is the pumping chamber that pumps blood to our body. The mitral valve opens to allow the oxygenated blood to flow into the left ventricular pumping chamber during the filling period of the heart’s cycle – a time called diastole.  Then as the heart contracts to send blood to the body, a portion of the cardiac cycle called systole, the valve should shut tight so that all the blood is pumped out to the body and none of the blood leaks back into the receiving chamber - the left atrium. Mitral valve prolapse is a condition where one or both leaflets are actually too long and potentially too thick, so that when they should be closing properly, they actually billow or prolapse back into the left atrium leaking blood into that atrium - a condition called mitral regurgitation.  You could think of this as if you had too much sail for the mast of a sailboat.  Therefore, with mitral valve prolapse, there is an inherited abnormality of the leaflets and their supporting structures – fine, delicate cord-like strands, called chordae, that leads to the improper sealing of the valve and, hence, the valve leaks the blood back into the receiving chamber.  Over time, this can not only raise the pressure in the lungs, but can lead to enlargement and decrease in the pumping action of the heart.  In severe cases of mitral valve prolapse and mitral regurgitation patients may need to be considered for surgical repair of their valve.     
Mitral valve prolapse is a genetic condition effecting the integrity of the mitral valve tissue.  It is a common diagnosis and effects approximately 20 million Americans, but only a small percentage ever get symptomatic enough to require surgery to fix this leaking valve. 

The mitral valve is located between the heart’s left atrium and left ventricle, which is the main pumping chamber that sends blood to the body. The most common mitral valve problem is leaking, or prolapse. For example, when a person tries to climb stairs, the heart pumps blood harder, but in the case of a leaking mitral valve, half the blood leaks back into the chamber. This makes the heart inefficient.

A patient might have shortness of breath and/or retain water. During a physical examination, a physician would hear a heart murmur and likely order an echocardiogram.

The most common valve problem is mitral valve prolapse (the name mitral, by the way, comes from the shape of the pope's hat with two leaves, called the miter), in which the valve between the left atrium and left ventricle doesn't slam closed fully.

Picture the valve as a sail. Normally it should be caught by the wind and snapped into place, but in mitral valve prolapse the sail is a little too big, or its ropes too long, and instead it rattles in the wind, closing kind of sloppily and letting some of the wind (that is, the blood) get past. That faulty process irritates the nerves in the atrium, which in turn can cause palpitations, sweating, and panic attacks.

Fifteen percent of women are diagnosed with mitral valve prolapse. Although men also have abnormal valves, the syndrome of anxiety attacks, sweating, and fast heart rates associated with these floppy valves is usually found in young women. It can be treated with drugs called beta blockers, but most folks end up outgrowing the condition.

Mitral Valve Prolapse
YOU: The Owner's Manual, Updated and Expanded Edition: An Insider's Guide to the Body that Will Make You Healthier and Younger

More About this Book

YOU: The Owner's Manual, Updated and Expanded Edition: An Insider's Guide to the Body that Will Make You Healthier and Younger

Between your full-length mirror and high-school biology class, you probably think you know a lot about the human body. While it's true that we live in an age when we're as obsessed with our bodies as...
This condition, which is also referred to as the floppy mitral valve syndrome, is very common, especially among women. In fact, many experts consider it a variation of normal function rather than a disease per se. Mitral valve prolapse is characterized by failure of a mitral valve leaflet to close properly. This makes a characteristic clicking sound that a doctor can usually hear. The floppy valve also may allow a backflow of some of the blood that normally should pass through the valve to the left ventricle.

Most of the time the condition is benign and entirely asymptomatic. In other instances, it can cause a variety of rather vague symptoms, including palpitations, chest pain, easy fatigue, feelings of breathlessness, and perhaps fainting. In rare cases, the person may develop serious cardiac arrhythmias.
Mitral valve prolapse is the most common heart problem. With this problem, the mitral valve bulges slightly back into the left atrium when it closes. This may allow a tiny amount of blood to leak backward. Minor symptoms such as minor chest pain or palpitations may occur. Mitral valve prolapse is usually not serious. It may be present from birth or may develop later in life.

This common condition (affects about 1-2% of the population) can be caused by Barlow's disease, which is an abnormality in the structure of the leaflets of the valves. It can also occur as an occasional consequence of aging, as the leaflets become less elastic. People with certain connective tissue diseases experience fibroelastic deficiency, a condition that affects valve function.

MVP causes the leaflets of the mitral valve to flop back into the left atrium with each heartbeat.

Mitral valve prolapse is a condition in which the two valve flaps of the mitral valve do not close smoothly or evenly. When the heart pumps (contracts) part of one or both flaps collapse backward into the left atrium. In some cases, the prolapsed valve lets a small amount of blood leak backward through the valve, which may cause a heart murmur.

Continue Learning about Heart Disease

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.