What is the cause of mitral regurgitation?

The mitral valve is located between the left atrium (LA) and the left ventricle (LV). In normal circulation, oxygenated blood comes from the lungs into the LA, Whe the LA contracts, the blood goes...

In the past, rheumatic fever was the most common cause of mitral valve insufficiency. However, the increased use of antibiotics for strep throat has made rheumatic fever rare in developed countries.

Mitral valve stenosis in adults, for example, is rarely congenital and is usually acquired, either a result of having rheumatic fever as a child or developing calcium obstruction in the valve later...

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Aortic regurgitation occasionally causes shortness of breath during normal activity. In serious cases, it causes the left ventricle of the heart to enlarge and may eventually lead to heart failure.