A 63-year-old woman who had undergone aortic valve replacement (AVR) with a 22-mm Medtronic Hall valve in May 1994 was admitted to the authors' hospital in June 2006 with epigastric pain and nausea. She presented with sudden precipitous deterioration of hemodynamics under high-dose catecholamines, but this improved in ca. 10 min. Valve motion was observed with fluoroscopy for a brief period as prosthetic valve dysfunction was suspected. After 10 min, transient insufficiency in closure of the prosthetic valve was revealed. The patient was diagnosed with prosthetic valve malfunction and referred for an urgent operation. At surgery, pannus was identified at the left ventricular aspect of the prosthetic valve in the aortic position, and this directly restricted leaflet movement during the closing phase. The leaflet movement showed no consistent pattern, but normal movement and half-closure occurred regularly to generate a phenomenon in which alternating normal hemodynamics and low-output syndrome was observed. The patient underwent AVR with a 17-mm St. Jude Medical Regent valve, and was discharged without any complications.