Sinus bradycardia st changes are two diagnoses of electrocardiogram, sinus bradycardia should be correctly called sinus bradycardia, refers to the sinus heart rate is lower than 60 beats / min; st segment changes refers to the performance of myocardial repolarization abnormality caused by various reasons. 1. Sinus bradycardia: Normal human heart rhythm should be sinus rhythm, heart rate in 60~100 times/minute, less than 60 times/minute sinus rhythm is called sinus bradycardia. 2.St segment change: st segment change refers to the performance of myocardial repolarization abnormality caused by a variety of reasons, there are many reasons, the most common is myocardial ischemia, in addition to cardiomyopathy, myocarditis, valvular disease, pericarditis, electrolyte disorders, cerebral vascular disease, etc., so the clinical diagnosis needs to be combined with other clinical information, such as blood sampling results and imaging data. If there are ECG abnormalities, please go to regular hospitals, doctors will combine clinical symptoms and various data to make professional judgment, do not blindly use drugs to avoid delaying the condition.