Mitral regurgitation causes


 * Associate Editor-In-Chief: Mohammed A. Sbeih, M.D. [mailto:msbeih@perfuse.org]; ; Varun Kumar, M.B.B.S.; Lakshmi Gopalakrishnan, M.B.B.S.

Overview
Mitral regurgitation is due to either perforation or prolapse of the leaflets, dilation of the mitral annulus or rupture of the papillary muscles or chordae tendineae. There are several phases of mitral regurgitation (acute, chronic compensated, and chronic decompensated).

Mechanical Basis of Mitral Regurgitation
The mechanical basis underlying mitral regurgitation includes the following:


 * Anterior mitral leaflet prolapse
 * Posterior mitral leaflet prolapse
 * Bileaflet prolapse
 * Restricted mitral leaflets
 * Apical tethering
 * Papillary muscle rupture
 * Ischemic papillary muscle rupture
 * Mitral leaflet perforation
 * Rupture or tear of the chordae tendineae
 * Dilation of the mitral annulus
 * "Functional MR" due to dilation of the heart itself

Acute Mitral Regurgitation

 * Heart attack or acute MI: Dysfunction or injury to the mitral valve following a heart attack. Papillary muscle rupture or dysfunction that is associated with ST elevation myocardial infarction.
 * Endocarditis: The infaction may cause perforation of the leaflet, erosion of the surrounding structures, or a vagetation may not permit the leaflets to coapt.
 * Trauma

Chronic Mitral Regurgitation

 * Mitral valve prolapse: This disorder now accounts for 45% of cases of mitral regurgitation in the Western world.
 * Ischemic heart disease / Coronary artery disease: This can be due to either papillary muscle dysfunction or left ventricular dilation and functional mitral regurgitation.  Ischemia is responsible for 3% to 25% of MR cases.
 * Rheumatic heart disease: In the past, this was the most common cause of MR in the Western world. In developing countries, rheumatic heart disease remains the most common cause.

Complete Differential Diagnosis of the Causes of Mitral Regurgitation
(By organ system)

Differential Diagnosis of the Causes of Acute Mitral Regurgitation
In alphabetical order:


 * Balloon valvuloplasty of the mitral valve
 * Infective endocarditis
 * Papillary muscle rupture
 * ST elevation myocardial infarction
 * Trauma with disruption of the chordae tendineae

Differential Diagnosis of the Causes of Chronic Mitral Regurgitation
In alphabetical order:


 * Atrial septal defect (Ostium primum)
 * Ankylosing spondylitis
 * Aortic insufficiency
 * Autosomal recessive conditions
 * Cabergoline
 * Collagen vascular diseases
 * Contractural arachnodactyly
 * Dilatation of the left ventricle
 * Dilated cardiomyopathy
 * Ehlers-danlos syndrome
 * Endocarditis
 * Endocardial cushion defect
 * Endomyocardial fibrosis
 * Fabry disease
 * Fenfluramine
 * Functional mitral regurgitation due to left ventricular dilation
 * Heart tumors
 * Hypertension
 * Hypertrophic obstructive cardiomyopathy (HOCM)
 * Ischemic heart disease (Coronary artery disease)
 * Marfan's syndrome
 * Methysergide
 * Mitral valve prolapse
 * Osteogenesis imperfecta
 * Pergolide
 * Polychondritis
 * Polycystic kidney disease-adult (autosomal dominant type)
 * Pseudoxanthoma elasticum
 * Rheumatic heart disease
 * Rheumatoid disease
 * Systemic lupus erythematosus (SLE)
 * Syphilis
 * Takotsubo cardiomyopathy
 * Turner syndrome
 * X-linked inherited conditions such as fabry disease