Snapshot A 23-year-old girl presents to the emergency room with shortness of breath, pleuritic chest pain, and hemoptysis. She is found to be tachycardic; her pulse is 102/min. She has a history of DVTs requiring heparin at age 20. However, she has not been on any maintenance therapy. Clinical suspicion for a pulmonary embolism is high, and a chest spiral CT scan is ordered. The CT shows a saddle embolism. Heparin is started immediately. Introduction Pathogenesis login to view 7 more bullets Genetics login to view 1 more bullet Risk factors login to view 3 more bullets Presentation Symptoms/physical exam login to view 4 more bullets Evaluation Normal PT, PTT, and thrombin time Reduces the increase in PTT following heparin administration Heparin cofactor assay, an antithrombin functional assay login to view 1 more bullet Differential Diagnosis HIT Protein C/S deficiency Factor V Leiden mutation Treatment For acute thrombosis login to view 1 more bullet For maintenance therapy login to view 1 more bullet Medical therapy login to view 2 more bullets Prognosis, Prevention, and Complications Prognosis login to view 2 more bullets Prevention login to view 3 more bullets Complications login to view 1 more bullet