Causes and risk factors of Mitral Regurgitation

There are various causes of inadequate closure of the mitral valve.

In general, there are two types of mitral regurgitation:

• Primary (degenerative) In this case there is a problem with the valve itself. In most cases, it is due to a degeneration of the valve that causes one of the chordae tendineae to rupture, leading to a prolapse in one of the leaflets. In other cases, the valve tissue may be excessive and not close properly (as in myxomatous degeneration of the valve, which is also called Barlow's disease in extreme cases). Other less common diseases that can cause primary regurgitation are infections (endocarditis), congenital valve defects (valve abnormalities present from birth) and rheumatic involvement, among others.
• Secondary (functional) The valve itself is normal, but it is not able to function normally due to a problem with the chambers (left atrium, left ventricle) between which it is located. This usually occurs if the left ventricle dilates or has been affected by a myocardial infarction. This makes the damaged area of ​​the heart muscle pull on the papillary muscle and the chordae, preventing the valve from closing properly. It can also appear due to dilation of the mitral annulus of the left atrium.