Mitral Valve Prolapse (MVP)
(See also Overview of Heart Valve Disorders.)
Mitral valve prolapse is a disorder in which the valve flaps (cusps) bulge into the left atrium when the left ventricle contracts, sometimes allowing leakage (regurgitation) of blood into the atrium.
Mitral valve prolapse is sometimes caused by weakness in the tissue of the valve.
Most people have no symptoms, but some people have chest pain, a rapid pulse, awareness of heartbeats, migraine headaches, fatigue, and dizziness.
Doctors make the diagnosis after hearing a characteristic clicking sound through a stethoscope placed over the heart and confirm the diagnosis with echocardiography.
Most people do not need treatment.
The mitral valve is in the opening between the left atrium and the left ventricle. The mitral valve opens to allow blood from the left atrium to fill the left ventricle and closes as the left ventricle contracts to pump blood into the aorta. Prolapse means that the valve flaps bulge back into the left atrium when the left ventricle contracts. With prolapse, blood sometimes leaks (regurgitates) back into the atrium (see also Mitral Regurgitation).
About 1 to 3% of people have mitral valve prolapse. It causes serious heart problems only if the regurgitation becomes severe, infection of the valve occurs (see Infective Endocarditis), or weak tissue ruptures.
The cause is usually excessive lengthening of the valve tissue due to a weakness in the tissue of the valve (myxomatous degeneration). Myxomatous degeneration is genetic. Other disorders that seem to increase the risk of mitral valve prolapse include rheumatic heart disease, Marfan syndrome, and Ehlers-Danlos syndrome.
Most people with mitral valve prolapse have no symptoms. Others have symptoms that are difficult to explain on the basis of the mechanical problem alone. These symptoms include chest pain, a rapid pulse, palpitations (awareness of heartbeats), migraine headaches, fatigue, and dizziness. In some people, blood pressure may fall below normal when they stand up (a disorder called orthostatic hypotension).
Doctors diagnose mitral valve prolapse after hearing the characteristic clicking sound through a stethoscope. Regurgitation is diagnosed if a murmur is heard when the left ventricle contracts. Echocardiography enables doctors to view the prolapse and determine the severity of regurgitation if present.