患者男、65岁,因“发作性胸闷、气短伴大汗5天”入院。入院后经心电图、超声心动图、心肌酶、肌钙蛋白等检查,诊断为冠心病、急性下壁心肌梗死、三度房室阻滞、心功能Ⅳ级。因心动过缓行临时心脏起搏术,起搏参数:R波感知灵敏度2.5mV, Male patient, 65 years old, because of “paroxysmal chest tightness, shortness of breath with sweating 5 days ” admission. After admission by electrocardiogram, echocardiography, myocardial enzymes, troponin and other tests, diagnosis of coronary heart disease, acute inferior wall myocardial infarction, third degree atrioventricular block, cardiac function Ⅳ. Temporary cardiac pacing due to bradycardia, pacing parameters: R wave sensing sensitivity of 2.5mV,