Objective:To explore the effect of intravenous thrombolysis in patients with acute ST segment elevation myocardial infarction (STEAMI) caused by acute occlusion of venous bridging vessels.Methods:The clinical data of a patient with acute STEMI caused by acute occlusion of venous bridge in the North China University of Science and Technology Affiliated Hospital in 2019 was retrospectively analyzed.A 58-year-old male patient underwent coronary artery bypass grafting (CABG) 12 years ago.He was re-admitted to the hospital due to acute inferior ST-segment elevation myocardial infarction for 4 hours.He was given Immediately aspirin 0.3 g chewed, ticagrelor 180 mg orally, heparin 4000 U intravenous injection.Next, he was given 50 mg of recombinant prourokinase intravenous thrombolysis.The successful thrombolysis was judged by observing the relief of chest pain symptoms, the ST segment of ECG falling down and the moving of myocardial enzyme peak.Coronary angiography was performed to observe the pathological changes of coronary artery and Bridge in situ, and further treatment strategies were formulated.Cardiac ultrasound examination was performed to understand the structure and function of the heart.The patients were followed up for 1 year to observe whether there were angina pectoris and cardiovascular events.Results:Thrombolytic therapy was successful at 1 hour.Coronary angiography was performed on the 8th day after acute inferior STEMI.The culprit vessel was ascending aorta great saphenous vein right coronary artery.The whole course was diffuse lesions with a large number of thrombus shadows.In situ, the left main coronary artery was diffuse 60% stenosis, the ostia of anterior descending branch and right coronary artery were completely occluded, and the proximal part of circumflex artery was completely occluded.The patients were given intensive antithrombotic therapy for 14 days, and he got better and was discharged.On the 41st day after acute STEMI, coronary angiography was reexamined.Thrombus shadow in aorta great saphenous vein right coronary artery disappeared.Echocardiography showed that left ventricular diastolic diameter was 53 mm and ejection fraction was 55%.The patient was given improved lifestyle and intensive drug treatment.One year after myocardial infarction, the patient had no angina pectoris and was competent for daily work and life.Conclusion:For patients more than 10 years after CABG, with chronic occlusion of coronary artery in situ, when acute STEMI caused by venous bridge occlusion, intravenous thrombolytic therapy is in line with the principle of early reperfusion treatment and has a good prognosis.