Objective To investigate the effects of early intervention by metoprolol injection on heart rate(HR), blood pressure(BP) , the product of HR and SBP (HRxSBP) and heart rate variability(HRV) in patients with acute coronary syndrome (ACS).

• 目的 研究急性冠状动脉综合征(ACS)早期应用美托洛尔注射液对患者心率、血压、心率血压乘积及心率变异性(HRV)的影响。