Abstract
BACKGROUND: Pannus formation may disturb the leaflet movement of the prosthetic valve. CASE PRESENTATION: A 61-year-old woman presented with exertional dyspnea. She had undergone mitral valve replacement with a bioprosthetic valve 31 years ago, which was replaced with a tilting disc valve 22 years ago. The present laboratory findings revealed hemolytic anemia. Echocardiography showed an increased mean pressure gradient through the mitral valve and moderate to severe regurgitation around the minor orifice of the tilting disc valve. She therefore underwent a third operation. Pannus formation was found on the prosthetic valve ring, but it did not obliterate the prosthetic valve orifice. After removing the valve, the posterior wall of the left ventricle was seen to be associated with thickened endocardium. A bileaflet valve was implanted. Postoperative echocardiography showed that the implanted valve functioned well. CONCLUSIONS: Nonstructural dysfunction of the mechanical heart valve might occur long after operation. These changes are particularly observed with a tilting disc valve.