Intravascular hemolysis associated with porcine mitral valve calcification in children.

Intravascular hemolysis was present in 5 of 16 children who underwent porcine valve replacement. Each patient had an abnormal blood smear pattern and reticulocytosis and one or more biochemical changes indicative of hemolysis. In all five patients, the porcine valve was calcified. Cardiac catheterization demonstrated severe mitral stenosis and minimal mitral insufficiency in each of the patients with intravascular hemolysis. The presence of hemolysis is indicative of valve dysfunction.