Mitral insufficiency Mitral insufficiency Mitral regurgitation (MR), Mitral insufficiency (abbreviation MI best avoided because it is more commonly used in lieu of myocardial infarction), or mitral incompetence 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 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. MR is the most common form of valvular heart disease. The symptoms associated with MR are dependent on
Mitral valve away from the free margin. This disposition has important effects on systolic stress distribution physiology The mitral annulus is a fibrous ring that is attached to the mitral valve leaflets. Unlike prosthetic valves, it is not continuous. The mitral annulus is saddle shaped and changes in shape throughout the cardiac cycle. The annulus contracts and reduces its surface area during systole to help provide complete closure of the leaflets. Expansion of the annulus can result in leaftlets that do not join soundly together, leading to functional mitral regurgitation. The normal diameter of the mitral annulus is , and the circumference