What is mitral valve regurgitation?

Mitral valve regurgitation is the backwards leakage of blood through the mitral valve each time the left ventricle contracts (check out the blog post on how the heart works to see where this is in the flow of blood). When the valve allows leakage backwards it means that the blood flows in two directions during heart muscle contraction. When this happens, some blood flows through the aortic valve, as it should, whilst some blood flows back into the atrium - which is should not.

The American Heart Association has a great video representation of mitral valve regurgitation here.

This leakage or regurgitation can increase blood volume and by therefore pressure in the atrium (where it has flowed back to). This increased pressure can in turn increase pressure in the veins which run from the lungs to the heart and if this is severe this can result in fluid build up in the lungs.


  • Mild cases of mitral regurgitation can be without symptoms.

  • More severe cases of mitral regurgitation can result in heart palpitations, particularly if the patient is lying on their left side.

  • Very severe cases can result in heart muscle enlargement to maintain forward flow of blood this can in turn lead to heart failure. In these cases symptoms can include shortness of breath, coughing, congestion around the heart and lungs and swelling of legs and feet.

Associated conditions:

Due to the backward leaking the left atrium often enlarges. This can in turn develop a rapid and disorganised motion of the heart - this is called atrial fibrillation. The heart's pump action then becomes less efficient. Atrial fibrillation can be associated with stroke and clots as the blood doesn't flow properly.


Treatment for mild cases of mitral regurgitation can include anticoagulation medication. However, more often than not surgery to replace or repair the valve is needed.

This article is intended to inform and give insight but not treat, diagnose or replace the advice of a doctor. Always seek medical advice with any questions regarding a medical condition.