Acute occlusion of a bileaflet mechanical mitral valve prosthesis resulting from external cardiac compression.

A 45-year-old woman with a history of rheumatic mitral disease underwent valve replacement. After surgery, the patient became hemodynamically unstable. A transesophageal echocardiogram showed an underfilled left ventricle with a clot impinging on the lateral aspect of the left ventricle and a malfunctioning mitral valve prosthesis. After evacuation of the clot in the operating room, the mitral valve prosthesis began functioning normally. The prosthesis malfunction resulted from external cardiac compression. This dynamic device malfunction was replicated when the surgeon compressed the lateral aspect of the heart. To our knowledge, this dynamic form of leaflet dysfunction from external compression has not been described. This case highlights the importance of closely evaluating prosthetic valve function in the setting of hemodynamic deterioration.