What is mitral valve prolapse?
Mitral valve prolapse (MVP) is a heart valve condition marked by the displacement of an abnormally thickened mitral valve leaflet into the left atrium during systole. In its nonclassic form, MVP carries a low risk of complications. In severe cases of classic MVP, complications include mitral regurgitation, infective endocarditis, and - in rare circumstances - cardiac arrest
usually resulting in sudden death.
The mitral valve, so named because of its resemblance to a bishop's miter, is the heart valve that prevents the backflow of blood from the left ventricle into the left atrium. It is composed of two leaflets (one anterior, one posterior) that close when the left ventricle contracts.
Each leaflet is composed of three layers of tissue: the atrialis, fibrosa, and spongiosa. Patients with classic mitral valve prolapse have excess connective tissue that thickens the spongiosa and separates collagen bundles in the fibrosa. This weakens the leaflets and adjacent tissue, resulting in increased leaflet area and elongation of the chordae tendineae. Elongation of the chordae often causes rupture, and is commonly found in the chordae tendineae attached to the posterior leaflet. Advanced lesions, also commonly involving the posterior leaflet, lead to leaflet folding, inversion, and displacement toward the left atrium.
Prolapsed mitral valves are classified into several subtypes, based on leaflet thickness, concavity, and type of connection to the mitral annulus. Subtypes can be described as classic, nonclassic, symmetric, asymmetric, flail, or non-flail. Prolapse occurs when the mitral valve leaflets are displaced more than 2 mm above the mitral annulus high points. The condition can be further divided into classic and nonclassic subtypes based on the thickness of the mitral valve leaflets: up to 5 mm is considered nonclassic, while anything beyond 5 mm is considered classic MVP. Classical prolapse may be subdivided into symmetric and asymmetric, referring to the point at which leaflet tips join the mitral annulus. In symmetric coaptation, leaflet tips meet at a common point on the annulus. Asymmetric coaptation is marked by one leaflet displaced toward the atrium with respect to the other. Patients with asymmetric prolapse are prone to severe deterioration of the mitral valve, with the possible rupture of the chordae tendineae and the development of a flail leaflet. Asymmetric prolapse is further subdivided into flail and non-flail. Flail prolapse occurs when a leaflet tip turns outward, becoming concave toward the left atrium, causing the deterioration of the mitral valve. The severity of flail leaflet varies, ranging from tip eversion to chordal rupture. Dissociation of leaflet and chordae tendineae provides for unrestricted motion of the leaflet (hence "flail leaflet"). Thus patients with flail leaflets have a higher prevalence of mitral regurgitation than those with the non-flail subtype.
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.
More information on mitral valve diseases (mitral valve prolapse, mitral valve regurgitation, mitral stenosis)
What is mitral valve disease? - There are many diseases which affect the mitral valve and its supporting structures. The most common disorder of the mitral valve is the partial backflow.
What is mitral valve prolapse? - Mitral valve prolapse (MVP) is a heart valve condition marked by the displacement of a thickened mitral valve leaflet into the left atrium during systole.
What causes mitral valve prolapse? - The cause of mitral valve prolapse is unknown. It is more common in people with low body weight and low blood pressure.
What're the symptoms of mitral valve prolapse? - Symptoms of mitral valve prolapse include fatigue, palpitations, chest pain, anxiety, migraine headaches, and even stroke.
How is mitral valve prolapse diagnosed? - Mitral valve prolapse is diagnosed in the course of a physical examination. Echocardiography is useful in diagnosing a prolapsed mitral valve.
What're the treatments for mitral valve prolapse? - Most people with mitral valve prolapse (MVP) do not have symptoms or need treatment. Mitral valve prolapse can be treated with surgical replacement of the mitral valve.
What is mitral valve regurgitation? - Mitral valve regurgitation happens when some of the blood in your heart leaks from the left ventricle into the left atrium.
What causes mitral valve regurgitation? - The causes of primary mitral regurgitation include myxomatous degeneration of the mitral valve, ischemic heart disease, coronary artery disease.
What're the symptoms of mitral regurgitation? - The symptoms associated with mitral regurgitation are dependent on which phase of the disease process the individual is in.
What're the complications of mitral regurgitation? - Complications of mitral regurgitation include congestive heart failure, atrial fibrillation, blood clot, endocarditis.
How is mitral regurgitation diagnosed? - The diagnosis of mitral regurgitation usually employs imaging studies such as echocardiography or magnetic resonance angiography of the heart.
What're the treatments for mitral regurgitation? - The treatment of mitral regurgitation depends on the acuteness of the disease and whether there are associated signs of hemodynamic compromise.
What is mitral valve stenosis? - Mitral valve stenosis is a narrowing of the opening of the mitral valve in the heart. Stenosis of the mitral valve prevents the valve from opening normally.
What causes mitral stenosis? - Mitral stenosis is often caused by having had rheumatic fever. Rheumatic fever can cause an infection in the mitral valve.
What are the symptoms of mitral stenosis? - Symptoms of mitral stenosis include shortness of breath, fainting, dizziness or tiredness, chest pains (angina), chest infections.
How is mitral valve stenosis diagnosed? - Mitral valve stenosis is usually detected by a physician listening to heart sounds. The diagnosis of mitral stenosis is most easily made by echocardiography.
What're the treatments for mitral stenosis? - The treatment options for mitral stenosis include medical management, surgical replacement of the valve, and percutaneous balloon valvuloplasty.
Mitral valve repair and replacement - Mitral valve replacement surgery is open-heart surgery that is done while the patient is under general anesthesia.