We present a case of a patient with calcific mitral valve stenosis and plasmatic hypercoagulability. Using thrombelastography, the patient was determined to have an abnormally large velocity of plasma thrombus growth and strength with reduced vulnerability to lysis. Critically, increased carboxyhemoglobin concentration (2.4 %) was present, likely secondary to hemolysis from mitral stenosis and engagement of systemic heme oxygenase. It was determined that the patient's plasmatic hypercoagulability was in part due to carboxyhemefibrinogen formation and iron-enhancement of coagulation via two thrombelastographic methods. In conclusion, future investigation of the involvement of both carbon monoxide and iron mediated hypercoagulability in the setting of stenotic valve disease is warranted.

Summary: Serial echocardiographic findings in a patientwith an Omniscience mitral prosthesis presenting progressive perivalvular pannus ingrowth are described. The first echocardiographic study was camed out one year after prosthesis implantation and showed decreased prosthetic opening velocity. As prosthetic thrombosis was suspected, hemodynamic study was performed, which proved normal. The patient remained in functional grade I1 for a year and a half prior to the onset of progressive dyspnea and dizzy spells. Echocardiogram was thus repeated and revealed the presence of multiple dense echoes behind the prosthetic disc. Three months after this last study, the patient presented acute pulmonary edema and reduction of disc excursion and opening and closing velocities. Hemodynamic study suggested prosthetic obstruction. Surgery revealed the presence of perivalvular pannus trapping the prosthetic disc. The prosthesis was subsequently replaced by a Bjork-Sorin. This case emphasizes the usefulness of echocardiography in the early detection of perivalvular pannus ingrowth revealing prosthetic mobility anomalies, even before hemodynamic changes occur.