Myxomatous mitral valve disease

Abstract

Myxomatous mitral valve disease (MMVD) of the atrioventricular (AV) valves is characterized by the accumulation of glycosaminoglycans (myxamtous proliferation) and fibrosis of the valve leaflets and tendinous chordae. The condition has been given many names, including endocardiosis, chronic degenerative valvular disease, chronic valvular disease, chronic valvular fibrosis and acquired mitral or tricuspid regurgitation or insufficiency. The valvular degeneration leads to insufficient coaption of the valve leaflet, valvular regurgitation and, in some animals, eventually to congestive heart failure (CHF). The condition most commonly involves the mitral valve with or without involvement of the tricuspid valve. Isolated tricuspid myxomatous degeneration occurs but is less common. Likewise, myxomatous changes occur infrequently on the semilunar valves (especially the aortic) but are rarely of clinical importance. The chapter looks at Aetiology; Epidemiology and inheritance; Pathophysiology; Clinical signs; Diagnostic approach; Treatment; and Prognosis.