There are several causes for leaky heart valves. Birth defects can deform them. Infections can scar them. Heart attacks can damage them, and the mechanics of an enlarged heart can stretch out the opening so that the valve is no longer large enough to work effectively.
- Rheumatic fever —infectious diseases of several kinds can afflict the inside of the heart, leading to scarring of the heart’s valves. Rheumatic fever used to be a common cause of mitral valve damage but is seen infrequently today in the United States.
- Heart attack —inadequate blood supply to the heart can weaken the small muscles that hold the mitral valve in place, causing it to leak.
- Congenital deformity—several different types of congenital heart defects distort the mitral valve.
- Heart muscle disease—not only infections, but many other types of disease can weaken the heart muscle, stretching out the mitral valve ring so that the valve no longer closes. Among these causes are alcohol, certain drugs, radiation , muscular dystrophies, malnutrition, cancer , and a long list of inflammatory and metabolic disorders.
- Mitral valve prolapse—abnormal closure of the valve with protrusion of a leaflet tip backward into the left atrium, causing it to leak. This may me congenital or acquired.
The following factors increase your chance of developing mitral regurgitation. If you have any of these risk factors, tell your doctor:
- A history of rheumatic fever or other serious infectious disease
- Inflammatory diseases such as lupus and rheumatoid arthritis
- Storage diseases such as hemochromatosis and glycogen storage disease
- Heart disease
- Muscle disease
- Radiation exposure
- Exposure to certain drugs (eg, lithium, sulfonamides, cancer chemotherapy , phenothiazines)