Mitral Incompetence / Mitral regurgitation Mitral Incompetence/Mitral regurgitation (MR) or mitral insufficiency  is a disorder of the heart in which the mitral valve does not close properly when the heart pumps out blood. It is the abnormal leaking of blood from the left ventricle, through the mitral valve, and into the left atrium, when the left ventricle contracts, […]