Studies on thromboplastic and fibrinolytic activities of valvular tissue in rheumatic valvular disease.

While rheumatic valvular disease (RVD) is known to develop subsequent to rheumatic carditis, we examined whether in addition to the inflammatory and repair process, thromboplastic and fibrinolytic activities of the valvular tissue play a contributory role in the pathogenesis of RVD. Both activities were higher in resected valves from RVD cases than in the controls. Tissue thromboplastin was localized in the valvular endothelium and the subendothelial connective tissue. Tissue fibrinolytic activity was prevalent in the small blood vessels of RVD valves, while it was lower on the surface of RVD valves than in the controls. High thromboplastic and low fibrinolytic activity in the surface layer of RVD valves may accelerate the deposition of thrombi, thereby inducing valvular thickening.