Mucoid Degeneration of Heart Valves: "Blue Valve Syndrome"

This paper is a report of a patient who had mucinous degeneration of the mitral valve which caused mitral insufficiency and congestive heart failure. There was no history of syphilis or bacterial endocarditis and no evidence of Marfan's syndrome. Gross and microscopic examination of the valve at surgery revealed mucoid degeneration. The literature concerning this valvular abnormality is reviewed. Cardiac valves afflicted with this lesion are found at surgery to be dilated with prominent thinning of the cusps and valve leaflets without intense fibrosis or calcification. Examination of sections discloses pools of a mucoid substance without intense inflammation, fibrosis, or calcification. Special stains such as alcian blue demonstrate increased mucopolysaccharides within the valves. This abnormality may be responsible for valvular insufficiency simulating rheumatic disease in significant numbers of patients. This lesion deserves consideration in the differential diagnosis of valvular insufficiency, especially when the etiology is obscure.