Mitral regurgitation

Mitral insufficiency
Mitral regurgitation (schematic drawing) During systole, contraction of the left ventricle causes abnormal backflow (arrow) into the left atrium. 1 Mitral valve 2 Left Ventricle 3 Left Atrium 4 Aorta
Classification and external resources
Specialty	Cardiology
ICD-10	I05.1, I34.0, Q23.3
ICD-9-CM	394.1, 424.0, 746.6
DiseasesDB	8275
MedlinePlus	000176
eMedicine	emerg/314
MeSH	D008944
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Mitral insufficiency (MI), mitral regurgitation 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. MI is the most common form of valvular heart disease.

The symptoms associated with MI are dependent on which phase of the disease process the individual is in. Individuals with acute MI are typically severely symptomatic and will have the signs and symptoms of acute decompensated congestive heart failure (i.e. shortness of breath, pulmonary edema, orthopnea, and paroxysmal nocturnal dyspnea), as well as symptoms of cardiogenic shock (i.e., shortness of breath at rest). Cardiovascular collapse with shock (cardiogenic shock) may be seen in individuals with acute MI due to papillary muscle rupture, rupture of a chorda tendinea or infective endocarditis of the mitral valve.

Individuals with chronic compensated MI may be asymptomatic for long periods of time, with a normal exercise tolerance and no evidence of heart failure. Over time, however, there may be decompensation and patients can develop volume overload (congestive heart failure). Symptoms of entry into a decompensated phase may include fatigue, shortness of breath particularly on exertion, and leg swelling. Also there may be development of an irregular heart rhythm known as atrial fibrillation.

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