缺血预适应对兔急性心肌梗死早期心电图改变的影响

The Effects of Ischemic Preconditioning on Electrocardiogram Changes in the Early Stage of Acute Myocardial Infarction in Rabbits

目的通过兔缺血预适应模型,观察缺血预适应(IPC)对兔急性心肌梗死早期心电图改变及梗死面积的影响。方法 40只大耳白兔随机等分为IPC组和非IPC,分别制造缺血预适应模型和急性心肌梗死模型。(1)对比分析两组缺血期:T波改变、ST段改变、R波振幅、缺血性J波、心律失常和梗死面积。(2)对比分析IPC组组内第一次预适应与三次预适应后缺血期前4项指标改变。结果(1)IPC组较非IPC组:T波增高幅度降低[缺血后40秒(0.40±0.11)mV vs(0.46±0.12)mV,P<0.05];J波发生率显著降低(0 vs 35%,P<0.01);室速、室颤发生率显著降低(分别为10.5%vs 30%和0 vs 15%,均P<0.05);心肌梗死面积减少[(30.8±6.6)%vs(35.3±6.9)%,P<0.05]。(2)IPC组组内三次预适应后缺血期比较第一次预适应缺血期:T波增高幅度降低[缺血后40 s(0.40±0.1)mV vs(0.46±0.1)mV,P<0.05];,波发生率显著降低(0 vs 25%,P<0.01)。结论心肌缺血预适应可以降低急性心肌缺血早期T波改变振幅,减少J波发生率、减少恶性室性心律失常,缩小梗死面积,保护缺血心肌。

Objective To observe the effects of ischemic preconditioning(IPC) on electrocardiogram(ECG) changes and infarction area in the early stage of acute myocardial infarction in rabbits.Methods 40 white rabbits were randomly divided into 2 groups,the IPC group and the non-IPC(infarction) group.ECG changes were observed in the ischemic stage in IPC group(after the third preconditioning) and the non-IPC group,and respectively after the first and the third preconditioning in the IPC group,which included the amplitude changes of T wave and R wave and the ST segment deviation,and the occurrence of J wave and arrhythmia.Meanwhile,the infraction area was also measured in each group and each period above mentioned.Results 1.The amplitude change of T wave decreased more significantly in IPC group than in non-IPC group[40 s ischemia(0.40 ±0.11) mV vs(0.46 ± 0.12) mV,P < 0.05],and after the third preconditioning than after the first preconditioning[40 s ischemia(0.40 ± 0.1) mV vs(0.46 ± 0.1) mV,P <0.05];2.The occurrence of J wave was significantly lower in IPC group than in non-IPC group(0 vs35%,P <0.01);and after the preconditioning than during the preconditioning in IPC group(0 vs 25%,P <0.01);3.The occurrence of malignant ventricular arrhythmia(ventricular tachycardia and ventricular fibrillation) was significantly lower in IPC group than in non-IPC group(P <0.05);4.The infarction area diminished significantly in IPC group than in non-IPC group[(30.8 ± 6.6)%vs(35.3 ±6.9)%,P<0.05].Conclusions The amplitude change decrease of T wave was preserved and the occurrence of J wave and the malignant ventricular arrhythmia was lowered by ischemic preconditioning in the early stage of myocardial ischemia;The infarction area was diminished by ischemic preconditioning in the early stage of myocardial ischemia.