In India, the prevalence of mitral valve prolapse (MVP) — when the valve between the heart’s upper and lower left chambers does not close properly — is between 3 and 16 per cent. This more or less reflects the international figure. It is slightly commoner in women, in whom it is likely to be less severe. The person does not even realise that he or she has a heart problem.

Most of the time, MVP patients do not have any symptoms. Sometimes, while listening to the heart with a stethoscope, the doctor may hear clicks and murmurs — the reason it is also called the click-murmur syndrome. This may lead to a request for some tests and evaluation.

Others may experience a fast, distressing, irregular heartbeat, especially in anxiety-causing or distressing situations. This may be associated with dizziness, feeling faint, difficulty in breathing and vague chest pain. There may be a fluttering feeling in the heart and a few extra thumps. When these symptoms occur in young women, they can be mistaken for hysteria. Exertion may precipitate symptoms in men. They are, therefore, more likely to be taken seriously and be medically evaluated.

Now master health check-ups, insurance and employee health evaluation are in vogue. MVP is picked up accidentally during these routine check-ups, or during anaesthesia evaluation for surgery.

The mitral valve is a bicuspid valve with two leaflets between the left atrium and left ventricle. They prevent the backflow of blood when the heart contracts. To work efficiently, the two leaflets of the valve have to close tightly.

The exact reason for mitral valve prolapse is not known. It may be that patients are born with leaflets that are too long, floppy or loose. These tend to buckle while closing. Sometimes they actually prolapse backwards, preventing the tight sealing of the blood flow tract.

This condition is usually congenital, which means that the person is born with it. It tends to run in families. It can be associated with other genetic disorders such as polycystic kidneys, brittle bones or Marfans syndrome and Ehlers–Danlos syndrome. If these conditions are present, the person should be evaluated for co-existing MVP.
MVP can occur later in life even if the valves were normal at birth. This can be due to myocardial infarction, rheumatic heart disease, hypertrophic cardiomyopathy or severe hyperthyroidism.

If MVP is suspected, a chest X-ray will help determine if the heart is enlarged. An echocardiogram will show the extent of the prolapse. An ECG will determine if there are rhythm abnormalities. A treadmill test, cardiac MRI or catheterisation may also be needed.

If the prolapse becomes severe, blood may leak in the heart. This can cause its function to deteriorate and result in heart failure. The malfunctioning valve can serve as a nidus for a severe bacterial infection called subacute bacterial endocarditis. The heart rhythm can become erratic and irregular. This can cause blood clots to form and get dislodged to various parts of the body.

Most people with MVP do not require aggressive treatment. They need to be followed up regularly. Cardiac arrhythmias and a fast heart rate are treated with beta-blocking drugs. Regular aspirin may be required to prevent blood clots. Heart failure may require diuretics. Later, if the prolapse is severe, surgery may be required.
The majority of people with MVP can lead a normal life with no restrictions on diet, exercise or lifestyle. Regular check-ups, however, are needed.

The writer is a paediatrician with a family practice at Vellore and the author of Staying Healthy in Modern India. If you have any questions on health issues please write to yourhealthgm@yahoo.co.in