The thrombus on the heart can not be dissolved may be because the thrombus for the old thrombus, if the new myocardial infarction, timely treatment, can be eliminated through thrombolysis thrombus. 1. Old thrombus: because old thrombus has undergone fibrosis, thrombolysis not only won’t dissolve it, but also may lead to the risk of bleeding, so the old thrombus on the heart can’t be dissolved; patients with old thrombus are often given antiplatelet aggregation, lipid regulation and cardioprotective treatment to prevent acute myocardial infarction from reoccurring. 2. New thrombus: usually cardiac thrombolytic therapy is the first choice of treatment in hospitals without the qualification of percutaneous coronary intervention; if the patient has sudden severe chest tightness, chest pain or accompanied by gastrointestinal discomfort, etc., he/she should seek medical treatment in time; for the diagnosed acute myocardial infarction within 12 hours of the onset of the disease, thrombolytic therapy can be performed after the assessment of the doctor to exclude contraindications. The effect of thrombolysis, i.e., whether the thrombus will melt away, varies according to the patient’s condition and the individual’s physique; it is necessary to carry out the next treatment under the guidance of a physician.