Myxomatous Mitral Valve Chordae. II: Selective Elevation of Glycosaminoglycan Content
K. Jane Grande-Allen PhD, Brian P. Griffin MD, Anthony Calabro PhD, Norman B. Ratliff MD, Delos M. Cosgrove, III MD, Ivan Vesely PhD

The elongation and rupture of chordae in myxomatous mitral valves is the leading cause of leaflet prolapse and mitral regurgitation. The content of water, collagen, DNA, and glycosaminoglycans (GAGs) were measured in chordae from 45 myxomatous mitral valves and 12 control valves. When GAG quantities were normalized to wet weight, dry weight, and DNA, they were significantly greater in myxomatous chordae than in control chordae. In particular, the myxomatous chordae contained significantly more chondroitin/dermatan 6-sulfate after normalization for both tissue wet weight and dry weight. Myxomatous chordae also contained more water and less collagen than controls. The excess GAGs and water may account for the gelatinous consistency of myxomatous chordae.