Definition of Mitral insufficiency

Mitral insufficiency: A malfunction of the mitral valve that permits the backflow of blood (regurgitation) from the left ventricle into the left atrium. Most mitral insufficiency is mild and requires no treatment. When severe, however, treatment with medications and sometimes surgery is necessary.

Source: MedTerms™ Medical Dictionary
http://www.medterms.com/script/main/art.asp?articlekey=4407
Last Editorial Review: 3/19/2012