Recently, we had a patient who was fitted with a temporary pacemaker that resulted in deep vein thrombosis of the lower extremities. He was cured by prompt thrombolytic therapy. So I studied the related knowledge. Summarize: 1, lower extremity DVT symptoms are insidious, 80% of the patients have no clinical manifestations, the main symptoms of lower extremity pain, swelling and activity limitation, common signs of lower extremity edema, edema is severe when the skin color bruising, and the state of the thrombus site (affected veins), the formation of the speed and extent of the relevant. 2, lower extremity DVT caused by pulmonary embolism PE is a silent killer, PE patients with a very high rate of sudden death, 43% of the patients in the onset of sudden death within 2 hours, of which 10% within 1 hour of sudden death, 36% of the sudden death in 2 to 24 hours, 1 month after the onset of the death of the case only accounted for 21%. 3.Anti-thrombotic treatment is recommended for patients receiving surgical operations (general surgery, gynecology, orthopedic surgery, obesity treatment and coronary artery bypass grafting and other major surgeries) or other interventional operations. 4, preventive measures: in the neighboring limbs or pelvic veins around the operation should be light, to avoid endothelial damage, avoid postoperative pillows under the calf to affect the calf deep venous return; encourage the patient’s feet and toes often active activities, and will be more deep breathing and coughing movements, as far as possible, early out of bed activities; if necessary, lower limbs wear medical elasticity long, socks, especially for the elderly patients with cancer or heart disease in the thoracic cavity abdominal cavity or pelvic cavity is greater than the After surgery, femur fracture, after and postpartum Women pay more attention. 5, anticoagulant drugs: intravenous shock anticoagulation therapy, heparin dosage of 60 ~ 70 U/kg, usage: 12 ~ 15 U/kg / h, intravenous drip, so that part of the activation time of plasminogen (APTT) up to 50 ~ 70 s, withdrawal of the drug should be gradually discontinued to avoid rebound thrombosis and ischemic events.