Mitral valve prolapse (MVP) is a common condition in which the mitral valve between the left upper chamber (left atrium) and left lower chamber (left ventricle) of the heart does not function properly. In most people, mitral valve prolapse does not cause any symptoms, usually does not cause any health problems, and does not require treatment.

In mitral valve prolapse, the valve flaps bulge (prolapse) upward into the left atrium rather than closing smoothly as the heart contracts. In rare cases, blood may leak backward through the prolapsed valve into the atrium. This condition is called mitral valve regurgitation.

For most people with mitral valve prolapse, the effect on the heart is minor, and there are no symptoms. People who have severe mitral valve regurgitation as a complication of mitral valve prolapse may develop symptoms of heart failure, which include shortness of breath, fluid buildup (edema), and fatigue.

Some people who have more significant changes in the structure of the valve or those who have mitral valve regurgitation may be at higher risk of a heart infection (endocarditis), heart failure, and abnormal heartbeats. In these people, antibiotics may be prescribed before certain procedures (such as dental work) to help prevent endocarditis.