Mitral Valve Prolapse

Mitral valve prolapse 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. It rarely causes serious heart problems.

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 Section 3, Chapter 21) 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 Section 3, Chapter 29) because bacterial infection of the heart valve (infective endocarditis) is a risk, although a small one.