Mitral insufficiency(MI), also known as mitral regurgitation(MR) , or mitral incompetence is a form of valvular heart disease in which the mitral valve does not close properly when the heart pumps out blood. It is the abnormal leaking of blood backwards from the left ventricle, through the mitral valve, into the left atrium, when the left ventricle contracts, i.e. there is regurgitation of blood back into the left atrium. Mitral insufficiency is the most common form of valvular heart disease.
