title: Pulmonary embolism - therapeutic dilemma.
mesh_terms: D002986:Clinical Trials as Topic; D006493:Heparin / Q000008:administration & dosage; D006801:Humans; D011655:Pulmonary Embolism / Q000188:drug therapy* / Q000517:prevention & control; D011897:Random Allocation
chemical_list: D006493:Heparin