Mitral valve prolapse (MVP) is a disorder in which the valve cusps bulge into the left atrium when the left ventricle contracts, sometimes allowing leakage (regurgitation) of blood into the atrium.
About 1 to 3% of people have mitral valve prolapse. The cause is usually redundancy of the valve tissue due to a hereditary weakness in the tissue of the valve (myxomatous degeneration). It causes serious heart problems only if the regurgitation becomes severe, infection of the valve occurs, or weak tissue ruptures.
Symptoms and Diagnosis
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 (see Diagnosis of Heart and Blood Vessel Disorders: Echocardiography and Other Ultrasound Procedures) enables doctors to view the prolapse and determine the severity of regurgitation if present.
Most people with mitral valve prolapse do not need treatment. If the heart is beating too fast, a beta-blocker may be taken to slow the heart rate and to reduce palpitations and other symptoms.
Last full review/revision March 2013 by Guy P. Armstrong