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Mitral Valve Prolapse

Also called: Billowing Mitral Cusp Syndrome, J.B. Barlow Syndrome, MVP, Floppy Valve Syndrome, Barlow Syndrome, Systolic Click Murmur Syndrome

- Summary
- About mitral valve prolapse
- Signs and symptoms
- Diagnosis methods
- Treatment options
- Questions for your doctor

Reviewed By:
Abdou Elhendy, MD, PhD, FACC, FAHA
Sumit Verma, M.D., FACC
Stephen D. Shappell, M.D., FACC, FCCP, FACP

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About mitral valve prolapse (MVP)

The mitral valve rests between the upper and lower chambers on the left side of the heart (the left atrium and left ventricle, respectively). The valve has two flaps that are connected to the heart muscle by cords called chordae tendineae.

In normal circulation, the mitral valve billows open to allow blood to flow from the left atrium to the left ventricle, where it is pumped out to the rest of the body through the aorta. In some cases, however, the flaps of the mitral valve or the chordae are abnormally formed, causing the valve to close incorrectly. This condition is known as mitral valve prolapse, or literally “the slipping of the mitral valve from its usual position in relation to other parts.”

MVP is the most common congenital heart valve abnormality in the United States. In the past, it was thought to affect from 5 to 15 percent of the population. However, researchers now believe that many of these individuals did not have MVP. Instead they had a bulging valve flap due to other conditions, such as a small heart or dehydration. With new criteria for diagnosing MVP, the National Heart, Blood, and Lung Institute estimates that less than 3 percent of the U.S. population actually have MVP.

In the vast majority of cases, mitral valve prolapse is benign, even if occasional symptoms are present. In fact, researchers have sometimes had difficulty assigning symptoms to mitral valve prolapse. Various studies have identified a wide range of symptoms that appear in people with mitral valve prolapse, such as chest pain or breathlessness. However, there is no consensus that these symptoms were actually caused by the prolapse or occurred by coincidence. Thus, mitral valve syndrome is a condition in which a variety of non-specific symptoms may be present, but may or may not be due to the prolapse.

Physicians may classify mitral valve prolapse in three categories:

Primary, or MVP that occurs on its own, for no apparent reason. In some individuals, it is accompanied by skeletal abnormalities (straight-back syndrome). It may also be inherited as familial mitral valve prolapse.
Secondary, or MVP that is associated with another disease, including Marfan syndrome, Ehlers-Danlos syndrome, polycystic kidney disease and others. The structural abnormalities in the mitral valve are the same with primary and secondary prolapse.
Functional, or MVP that is caused when an anatomically normal mitral valve is affected by abnormalities within the heart structure. This may occur in patients with hypertrophic cardiomyopathy.

Although most cases of mitral valve prolapse do not cause serious medical problems, the condition should be monitored. MVP is associated with more serious cardiac complications, including infective endocarditis, mitral valve regurgitation, arrhythmias and sudden cardiac death. Some research has also suggested that mitral valve prolapse is associated with transient ischemic attacks, or a temporary lack of blood flow to the brain that causes stroke symptoms. Although several studies have suggested a connection, other studies have not, and the link remains inconclusive.