目的　采用动物实验方法 ,探讨心肌缺血预处理 (MIP)对急性心肌梗死 (AMI)后QT间期离散度 (QTd)变化的影响。方法　观察AMI组 (A组 )与MIP组 (B组 )新西兰兔在AMI后的QTd ,并行心内电生理检查诱发室性心动过速 (VT) ,对两组的指标进行比较 ,同时设置假手术组 (C组 )作对照。结果　 3组手术前QTd比较著差异无显著性 (P 0 0 5 ) ;C组手术前后比较差异亦无显著性 (P 0 0 5 ) ;B组MIP前QTd与A组比较差异无显著性(P >0 0 5 ) ,在AMI后 ,B组QTd明显小于A组 (P <0 0 0 1)。结论　在AMI的家兔模型 ,B组QTd及诱发VT的发生率显著低于A组 ,提示MIP可以少AMI的QTd变化及室性心律失常发生。 Objective To investigate the effect of myocardial ischemic preconditioning (MIP) on QTd after acute myocardial infarction (AMI) by animal experiments. Methods The QTd of AMI group (A group) and MIP group (B group) after AMI were observed. The ventricular tachycardia (VT) was induced by intracardiac electrophysiological examination, and the indexes of the two groups were compared. At the same time, Surgical group (C group) as a control. Results There was no significant difference in QTd between the three groups before surgery (P 0 0 5). There was no significant difference between before and after surgery in C group (P 0 0 5) P> 0.05). After AMI, QTd in group B was significantly lower than that in group A (P <0.01). Conclusion In the rabbit model of AMI, the incidence of QTd and VT in group B was significantly lower than that in group A, suggesting that MIP could reduce the QTd of AMI and cause ventricular arrhythmia.