Heparin-associated thrombocytopenia with thrombosis presenting as large thrombi in the aorta.

H eparin-associated thrombocytopenia with thrombosis (HAlT) is an uncommon but serious complication of heparin therapy and may be fatal if not diagnosed promptly I I . 2]. It is characterized by a sudden decrease in platelet count, usually between 6 and I 2 days after initial exposure to heparin. with thrombosis of arteries. veins, or both I 1-31. The mortality and morbidity rates from this condition are high and may be decreased by early diagnosis [3, 4J. This diagnosis requires a high index of suspicion and the knowledge that the condition exists. We report a patient with heparin-associated thrombocytopenia with massive thrombosis in the ascending aorta and aortic arch, in whom the radiographic findings were misinterpreted as being caused by trauma.