Intracardiac thrombosis diagnosed by echocardiography in childhood: predisposing and etiological factors.

Eleven cases of intracardiac thrombi caused by different factors including protein-C deficiency are presented for discussion of the etiology and predisposing factors of intracardiac thrombi during infancy and childhood, and to stress the importance of protein-C deficiency as an etiological factor. Thrombi were localised in the left heart in five patients and right heart in five patients. One patient had both-sided thrombi. Four of our patients had dilated cardiomyopathy, one had mitral valve hypoplasia, and one had pulmonary valvar stenosis as the predisposing factors for thrombus formation. In three patients whose cardiac anatomies were completely normal, we determined protein-C deficiency as an etiological factor of thrombus formation. One of these had congenital protein-C deficiency and the other two had acquired temporary protein-C deficiency due to sepsis. In conclusion we recommend that protein-C deficiency should be investigated as an etiological factor in all cases of intracardiac thrombi irrespective of whether or not another predisposing factor is identified.