Congenital mitral valve malformation
Congenital mitral valve malformations can cause mitral stenosis and / or insufficiency. Fisher reported two cases of congenital mitral valve malformations in 1902, and more cases have been reported since the 1960s. Congenital mitral valve malformations are often associated with atrioventricular tube malformations, aortic dislocations, single ventricle, atrial septal defect, ventricular septal defect, left ventricular outflow tract or aortic outlet narrowing, aortic constriction, tetralogy of Fallot, etc. Congenital cardiovascular disease is present. Congenital mitral valve malformations alone are rare and account for only 0.6% of autopsy materials for congenital cardiovascular disease. It accounts for 0.21 to 0.42% of clinical cases. The mitral valve is composed of annulus, leaflets, chordae, papillary muscle and left atrium wall. Any one or several structural abnormalities can produce congenital mitral valve malformations. In most cases, multiple components are abnormally developed, resulting in narrowing of the left atrioventricular blood flow channel.