Valve adaptation as a cause of disc opening reduction in mechanical heart valves: the case of the Lillehei-Kaster valve

At fluoroscopy a decreased disc motion in mechanical heart prostheses is often a sign of valve thrombosis. On occasion, however, despite an exhaustive diagnostic work-up, common causes of prosthetic valve thrombosis are not found. In these cases the valve disc abnormalities are thought to be due to functional changes. We here report our experience with 5 consecutive patients carrying the Lillehei-Kaster prosthesis who had this fluoroscopic finding that was lately attributed to "valve physiologic adaptation". The time of onset, differential diagnosis and clinical/hemodynamic impact of valve adaptation are discussed.