猪急性心肌梗死模型建立中心律失常的防治体会

目的：总结猪急性心肌梗死模型建立过程中心律失常的发生特点及防治方法.方法：选择健康雌性家猪14只,3～5月龄,体重25～40 kg.随机分为2组：实验组（n＝8）行缺血预适应处理,依次扩张球囊阻断前向血流1 min、2 min、5 min,每次间隔60 s,然后扩张60 min,扩张压力为2 atm.在建立模型过程中,心率＞150次/min时即静脉推注美托洛尔5 mg.对照组（n＝6）不行缺血预适应处理,直接扩张球囊阻断前向血流60 min,扩张压力为2 atm,静脉不推注美托洛尔.2组动物发生室性早搏后均静脉推注利多卡因,发生室性心动过速、室颤后均行直流电复律.建立模型前、后行心电图检查,术中行心电监护.结果：2组动物在建模过程中均有室性心律失常发生,实验组6只发生室早（75.0%）,4只发生室速（50.0%）,3只发生室颤（37.5%）,无一只死亡,建模成功率为100%.对照组4只发生室早（66.7%）,4只发生室速（66.7%）,6只发生室颤（100%）,死亡2只（33.3%）,建模成功率为66.7%.实验组3只发生再灌注心律失常（37.5%）,对照组6只发生再灌注心律失常（100%）,2组比较差异有统计学意义（P＜0.05）.实验组动物较对照组动物缺血性心律失常发生晚（P＜0.05）.实验组动物直流电转复成功率高于对照组.结论：缺血预适应、静脉推注美托洛尔可以有效地减少急性心肌梗死建模过程中心律失常的发生,提高建模成功率.

Prevention and treatment of arrhythmia during the setting up of myocardial infarction model in swine

Objective: To observe the incidence of arrhythmia during the establishment of myocardial infarction model in swine and to find the ways of prevention. Methods: Fourteen pigs aged 3 to 5 months and weighed 25 kg to 40 kg were divided into two groups randomly. Artery was blocked 1 min, 2 min, 5 min by turns, interval 60 seconds everytime as a way of ischemic preconditioning in study group (n=8). Then the balloon was inflated with 2 atm to occlude the LAD for 60 mins. And metoprolol was given when heart rate was over 150 bpm. The balloon was inflated with 2 atm to occluded the LAD for 60 mins without ischemic preconditioning in control group (n=6). ECG and blood pressure were monitored during the process. Results: The incidence of premature ventricular beat happened in 6 animals in study group (75%) and in 4 animals in control group (66.7%); ventricular tachycardial happened in 4 animals in study group (50%) and in 4 animals in control group (66.7%); ventricular fibrillation happened in 3 animals in study group (37.5%) and in 6 animals in control group (100%). Tweleve animals setted up the acute myocardial infarction model successfully while 2 died of fibrillation in control group. Ten animals were confirmed as anterior septal AMI and four was confirmed as widespread anterior AMI by ECG. Conclusion: By ischemic preconditioning and medical therapy, the arrhythmia during the setting up of myocardial infarction model in swine can be prevented effectively.