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 small amounts of blood into the atrium.

About 2 to 5% of people have mitral valve prolapse. The cause is redundancy of the valve tissue often from myxomatous degeneration, a hereditary connective tissue disorder that causes weakness in the tissue of the valve. It causes serious heart problems only if the regurgitation becomes severe, infection of the valve occurs, or myxomatous 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 Symptoms and 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.

Treatment

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.

If regurgitation is also present, antibiotics should be taken before surgical, dental, or medical procedures (see Which Procedures Require Preventive Antibiotics?) because bacterial infection of the heart valve (infective endocarditis) is a risk, although a small one.

Last full review/revision May 2006 by Paul H. Tanser, MD