Heart failure is a condition in which the heart is not able to generate adequate blood output to meet the body's metabolic demands. The patient with CHF usually presents with complaints of a progressive decline in the ability to perform activities. Fluid accumulation leading to edema in the extremities and weight gain is also typical.

Cardiac enlargement usually develops in congestive heart failure. Enlargement of the heart frequently results in dilatation of the mitral valve opening (termed annulus). The dilated mitral annulus causes the mitral valve leaflets to pull apart allowing mitral regurgitation. Mitral regurgitation wastes cardiac energy, produces an increased volume load on the heart and is responsible for a progressive deterioration in cardiac performance.