Mitral valve prolapse, also known as click-murmur syndrome, Barlow's syndrome, balloon mitral valve, or floppy valve syndrome, is the bulging of one or both of the mitral valve flaps (leaflets) into the left atrium during the contraction of the heart. One or both of the flaps may not close properly, allowing the blood to leak backward (regurgitation). This regurgitation may result in a murmur (abnormal sound in the heart due to turbulent blood flow). Mitral regurgitation (backward flow of blood), if present at all, is generally mild.
It is estimated that mitral valve prolapse occurs in less than 3 percent of the population.
The mitral valve is located between the left atrium and the left ventricle and is composed of two flaps. Normally the flaps are held tightly closed during left ventricular contraction (systole) by the chordae tendineae (small tendon "cords" that connect the flaps to the muscles of the heart). In MVP, the flaps enlarge and stretch inward toward the left atrium, sometimes "snapping" during systole, and may allow some backflow of blood into the left atrium (regurgitation).
The cause of MVP is unknown, but is thought to be linked to heredity. Primary and secondary forms of MVP are described below.
Mitral valve prolapse may not cause any symptoms. The following are the most common symptoms of MVP. However, each individual may experience symptoms differently. Symptoms may vary depending on the degree of prolapse present and may include:
Depending on the severity of the leak into the left atrium during systole (mitral regurgitation), the left atrium and/or left ventricle may become enlarged, leading to symptoms of heart failure. These symptoms include weakness, fatigue, and shortness of breath.
The symptoms of mitral valve prolapse may resemble other medical conditions or problems. Always consult your physician for a diagnosis.
Persons with MVP often have no symptoms and detection of a click or murmur may be discovered during a routine examination.
MVP may be detected by listening with a stethoscope revealing a "click" (created by the stretched flaps snapping against each other during contraction) and/or a murmur. The murmur is caused by some of the blood leaking back into the left atrium. The click or murmur may be the only clinical sign.
In addition to a complete medical history and physical examination, diagnostic procedures for MVP may include any, or a combination, of the following:
In some situations where symptoms are more severe, additional diagnostic procedures may be performed. Additional procedures may include:
Specific treatment for mitral valve prolapse will be determined by your physician based on:
Treatment is not usually necessary as MVP is rarely a serious condition. Regular checkups with a physician are advised.
Persons with rhythm disturbances may need to be treated with beta blockers or other medications to control tachycardias (fast heart rhythms). In most cases, limiting stimulants such as caffeine and cigarettes is all that is needed to control symptoms.
If atrial fibrillation or severe left atrial enlargement is present, treatment with an anticoagulant may be recommended. This can be in the form of aspirin or warfarin (Coumadin®) therapy.
For the person with symptoms of dizziness or fainting, maintaining adequate hydration (fluid volume in the blood vessels) with liberal salt and fluid intake is important. Support stockings may be beneficial.
If severe mitral regurgitation resulting from a floppy mitral leaflet, rupture of the chordae tendineae, or extreme lengthening of the valve should occur, surgical repair may be indicated.
This condition is usually harmless and does not shorten life expectancy. Healthy lifestyle behaviors and regular exercise are encouraged.
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