Intracardiac thrombus associated with resistance to activated protein C.

Formation of thrombus in the heart is a rare event in children. Genetic risk factors determined for thrombophilia with additional exogenous risk factors may, none the less, promote cardiac thrombosis. We report on a boy without predisposing cardiac disease, heterozygous for resistance to activated protein C, who developed multiple thrombuses attached to the mitral valve which led to recurrent arterial thromboembolism. In addition this patient showed enhanced levels of lipoprotein (a).