Patients that are proficient in administering their own injection with dalteparin will be evaluated every other day by the physician investigator. On days of home injection, the study nurse will call the patient to check on the patient's status and to remind the patient of his/her daily injection. Patients will undergo a physical examination every other day by the physician investigator directed towards the clinically affected areas until a therapeutic response (INR 2-3) on oral warfarin has been achieved or the patient's clinical condition warrants modification of therapy with or without hospitalization. Patients will remain on study for a minimum of 5 days with at least 1 day of therapeutic oral anticoagulation.