非开胸法室壁瘤相关持续性单行性室性心动过速动物模型的建立

摘要

目的:探讨运用经皮球囊冠状动脉成形术(PTCA)球囊堵闭猪冠状动脉前降支(LAD)造成急性心肌梗死(AMI)后数周,形成左心室室壁瘤(LVA)并结合程序刺激方法,建立持续性单行性室性心动过速(SMVT)的非开胸动物模型.方法:中华实验小型猪7只,体质量(35 ±5)kg,运用PTCA球囊堵闭猪LAD形成AMI.存活猪在AMI后数周内行心室程序刺激诱发SMVT.术中及术后观察LAD、左心室造影及超声心动图改变,SMVT诱发、终止方式及SMVT周期变化.结果:5只猪证实左心室室壁瘤形成.术后4w对5只猪行程序刺激,诱发出11种SMVT,周长为(223.63 ±32.55)ms,且可被程序刺激和直流电复律终止.其中,7种SMVT为房室分离,4种SMVT为室房1∶1逆传；8种呈左束支传导阻滞,3种呈右束支传导阻滞.心电图演变过程与人体心肌梗死过程基本一致.结论:运用PTCA球囊堵闭LAD造成AMI后LVA形成,并通过程序刺激成功诱发SMVT.此种非开胸法建立室壁瘤相关持续性单行性室性心动过速动物模型成功率高.研究结果提示,折返可能是室壁瘤相关室性心律失常的电生理基础,为进一步研究治疗奠定了实验基础.%Objective:To develop a close-chest swine model of sustained monomorphic ventricular tachycardia (SMVT) after ventricular aneurysm induced by myocardial infarction ( MI) and to investigate induce method and successful rate of inducing ventricular tachycardia (VT) in experimental ventricular aneurysm model. Methods:7 swines that weighed (35 ±5)kg were studied. Each animal underwent a closed-chest procedure of induction of MI by temporary balloonocclusion of the left anteroir descending ( LAD) coronary artery. After a follow-up period of several weeks,SMVT was induced during programmed electrical stimulation using "clinical" stimulation protocol. During and after the operation, angiography, electrocardiogram was recorded. Echocardio-graphy were investigated to confirm the presence of ventricular aneurysm. Results :5 swines formed ventricular aneurysm. All survived animals underwent an electrophysiological study in 4 weeks after creation of experimental MI. 11VTs were terminated by ventricular programmed stimulation and cardioversion. The induced VTs had a mean cycle length of VT (223. 63 ± 32. 55) ms. Electrocardiogram prompted a similar process of MI between swine and human. Conclusion; A closed-chest swine model of aneurysm after AMI using balloon occlusion LAD is feasible and has a relatively high induction rate and a low mortality. Ventricular arrhythmia and reentrant cycle may be associated with aneurysm relative ventricular arrhythmia which is worthy of further study.