Skyline Family Practice
Mitral valve prolapse is frequently diagnosed in healthy people and is, for the most part, harmless. Most people suffer no symptoms whatsoever from mitral valve prolapse. Estimates are that 1 in 10 to 1 in 20 individuals has mitral valve prolapse. It is also called floppy valve syndrome, Barlow's or Reid-Barlow's syndrome, ballooning mitral valve, midsystolic-click-late systolic murmur syndrome, or click murmur syndrome.
Mitral valve prolapse can be present from birth or develop at any age. It occurs in both men and women, but is more common in women. Mitral valve prolapse is one of the most frequently made cardiac diagnoses in the United States.
Although in general healthy hearts are structurally similar, like other parts of the body, there are individual variations. The heart's valves work to maintain the flow of blood in one direction, ensuring proper circulation. The mitral valve controls the flow of blood into the left ventricle. Normally when the left ventricle contracts the mitral valve closes and blood flows out through the aortic valve. In mitral valve prolapse the shape or dimensions of the leaflets of the valve are not ideal; they may be too large and fail to close properly or balloon out, hence the term "prolapse." When the valve leaflets flap, a clicking sound may be heard. Sometimes the prolapsing of the mitral valve allows a slight flow of blood back into the left atrium, which is called "mitral regurgitation," and this may cause a sound called a murmur. Some people with mitral valve prolapse have both a click and a murmur and some have only a click. Many have no unusual heart sounds at all; those who do may have clicks and murmurs which come and go.
Mitral valve prolapse is commonly diagnosed by listening to the sounds that the heart makes or occasionally is discovered through echocardiographic tests. Sometimes once a physician has heard the characteristic sounds of mitral valve prolapse through a stethoscope, other tests may be ordered. Echocardiography is a common and painless test which uses sound waves of a very high frequency which travel through the layers of the skin and muscle to produce an image of the heart which can be seen on a screen. In this sense it is a technique similar to radar or sonar imaging.
The vast majority of people with mitral valve prolapse have no discomfort whatsoever. Most are surprised to learn that their heart is functioning in any way abnormally. Some individuals report mild and common symptoms such as shortness of breath, dizziness, and either "skipping" or "racing" of the heart. More rarely chest pain is reported. However, these are symptoms which may or may not be related to the mitral valve prolapse.
In most cases no treatment is needed. For a small proportion of individuals with mitral valve prolapse, beta blockers or other drugs are used to control specific symptoms. Serious problems are rare, can easily be diagnosed and if necessary, treated surgically.
The overwhelming majority of people with mitral valve prolapse are free of symptoms and never develop any noteworthy problems. However, it is important to understand that in some cases mitral regurgitation, that is, the flow of blood back into the left atrium, can occur. Where mitral regurgitation has been diagnosed, there is an increased risk of acquiring bacterial endocarditis, an infection in the lining of the heart. To prevent bacterial endocarditis many physicians and dentists prescribe antibiotics before certain surgical or dental procedures.
It may seem that mitral valve prolapse is becoming more common but actually it has probably always been around and was simply less well recognized. For instance, some historians cite the observation of "soldier's heart" made by Dr. J.M. Dacosta during the Civil War as the first description of mitral valve prolapse. Contemporary understanding of this condition advanced, however, with the work in 1966 of Dr. J.B. Barlow in South Africa when he related the characteristic sounds to the specific anatomical characteristics of the leaflets in mitral valve prolapse. More precise identification became possible as increasingly sophisticated diagnostic tools were available.
The increased visibility of this disorder has also come from one-time or cross-sectional studies of healthy people as well as longitudinal studies which follow individuals over years such as the Framingham Study where routine tests have shown that it is commonly present. No one knew quite how common, and unnoticed, mitral valve prolapse was until 1976 when researchers examined 100 presumably healthy young students at a woman's school. Their finding, that it occurred frequently and that as many as 1 in 10 have mitral valve prolapse, was then underscored by findings from the Framingham study in 1983, as well as by reports from other research.
The overwhelming majority of people with mitral valve prolapse are free of symptoms and never develop any noteworthy problems. Whether or not there is any discomfort, health care providers should be notified of the existence of mitral valve prolapse so that recommendations can be made about the advisability of using antibiotics to protect against bacterial endocarditis.
U.S. Department of Health and Human Services
Public Health Service
National Institutes of Health
National Heart, Lung, and Blood Institute
[Rees AM (ed):Phoenix, Oryx Press, 1995, pp 200-201.]
Unless otherwise noted: this document was originated by, reviewed and/or edited by Tripp Bradd, MD
current revision/review: 8/26/2008