Murmurs of the heart

Health News,  April, 1991  

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The additional tests may include chest X-rays and detailed electrocardiograms - heart wave patterns obtained by placing electrodes on the chest (a painless test). If there is any evidence of a significant murmur the person will be referred to a cardiologist for further assessment. The cardiologist may use a variety of clinical tests to examine heart function such as having the person breathe in and out while checking the heart, also testing its action during positional changes, after sit-ups, when going from squatting to standing, during leg lifts and handgrip exercises to determine whether and how a heart murmur should be treated.

Mitral valve prolapse - one of the commonest heart murmurs

Mitral valve prolapse (MVP) also known as the "click-murmnur syndrome" (after the sounds heard through the stethoscope), or a "floppy valve," is one of the commonest causes of a heart murmur in young adults, especially women. No one knows why, but about four per cent of adults have a click, often accompanied by a late systolic murmur where there's some looseness in the leaflets of the mitral valve and its supports The mitral valve separates the heart's left atrium and left ventricle - preventing blood from flowing backwards as the left ventricle contracts and pumps blood to the rest of the body. First recognized in the 1960s, MVP was originally thought to be a harmless and very common condition but has since been more accurately defined. At almost any workplace or social gathering someone now seems to have a heart murmur due to MVP. This sudden flurry of heart murmurs isn't an epidemic but simply means that a probably ancient quirk of nature is more often recognized. In the past, MVP was attributed mainly to some illness, particularly rheumatic fever. But this theory is now discounted since many people who've never had rheumatic fever have a mitral valve murmur that's not due to a diseased valve but simply one that billows as the heart contracts. Ideally its flaps shut tightly to form a taut seal. But if the mitral valve is slightly floppy and doesn't shut completely its flaps or leaflets may billow (prolapse) as it closes, causing a click. If the valve billows enough to prevent proper closure, there will be an accompanying murmur (hiss or vibration).

MVP murmurs tend to run in families and may be an inherited trait. Studies suggest that they are most common in slim, tall women with "model-type" figures, long arms and a flattish ribcage. Mild mitral valve prolapse isn't usually serious but a loud murmur may be accompanied by significant symptoms and, in serious cases, there may be degeneration or loss of elasticity (myxomatosis) of the mitral valve leaflets. However, a prolapsed mitral valve does not generally worsen, usually posing no medical problem other than a possibly increased vulnerability to heart infections. MVP is sometimes linked to connective tissue disorders and can occur in the severely malnourished or women with anorexia nervosa (eating disorders).