Degenerative mitral valve regurgitation: understanding basic concepts and new developments.

Chronic degenerative mitral regurgitation is the most common valvular disease in the United States. The objective of this review article is to impart a balanced understanding of the basic concepts and new developments in assessment and management of patients with severe degenerative mitral regurgitation. Etiologic, epidemiologic, pathologic, and physiopathologic concepts are discussed, as well as the importance of surgical mitral valve repair as the current gold standard treatment. Research efforts in "decoding" the natural history and prognosis of patients with severe degenerative mitral regurgitation have produced important insights into the surgical timing of patients with asymptomatic mitral regurgitation, and the concept of early restorative surgery has emerged.