Methods 48 cases of the first AMI were divided into two groups: ischemic preconditioning(IP) group with angina within 24 hours before AMI onset, control group without angina.

• 方法：48例首发急性心肌梗死患者根据心梗前24小时内有无心绞痛发作分为缺血预适应组和对照组，分别观察心梗面积、心肌酶峰值、心功能状况及严重并发症。