非开胸法建立持续性单形性室性心动过速动物模型的研究

The Study of a Close-chest Pig Model of Sustained Monomorphic Ventri cular Tachycardia After Myocardial Infarction.

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造成急性心肌梗死 (AMI)后数周建立持续性单形性室性心动过速 (VT)的非开胸法动物模型的方法。猪 1 3只 ,体重 30± 5kg ,运用PTCA球囊堵闭猪左前降支(LAD)形成AMI。存活猪在AMI后数周内进行心室程序电刺激诱发持续性单形性VT ,观察VT诱发、终止的方式及VT诱发的时间窗等。结果 :9/ 1 3只猪形成AMI,经左心室造影及心脏超声检查证实左室心尖、前间隔、左室前壁室壁瘤形成。术后 2～ 2 0周内 9只猪接受平均 1～ 2次电生理检查 ,运用程序电刺激方法 ,8只猪共成功诱发出 1 6种单形性持续性VT ,1只猪仅诱发出非持续性短阵VT。VT周长为 2 54± 65ms ,持续时间 1 8± 1 6min,最长达 62min。程序电刺激和直流电复律可终止VT ,1 0种VT表现为室房分离 ,6种VT室房均为 1∶1逆传 ;9种呈左束支阻滞型 ,7种呈右束支阻滞型。结论 :运用PTCA球囊堵闭冠状动脉造成MI后室壁瘤形成 ,通过程序电刺激的方法可成功建立持续性单形性VT非开胸动物模型 ,成功率较高 ,VT诱发的时间窗长。

To develop a close chest pig model of sustained monomorphic ventricular t achycardia(SMVT) after myocardial infarction(MI) and to investigate induce metho d an d successful rate of inducing ventricular tachycardia(VT) in experimental MI mod el,thirteen pigs that weighed 30±5 kg were studied.Each animal underwent a clos ed chest procedure of induction of MI by temporary balloon occlusion of the lef t anteroir descending (LAD) coronary artery.After a follow up period of several weeks,SMVT was induced during programmed electrical stimulation using 'clinica l' stimulation protocol.Results:Nine of thirteen pigs underwent successful indu ction of acute MI and aneurysm.Four of thirteen pigs died of ventricular fibrill ation .All survived animals underwent an electrophysiological study between 2～20 week s after creation of experimental MI.Nine survived pigs were given 1～2 times ele ctrophysiologic study.Sixteen episodes of SMVT were induced in 8 pigs.Non susta ined VT was induced in 1 pigs.The induced VTs had a mean cycle length of VT 254 ±65 ms.The episodes of VT lasted from 30 seconds to 62 min (average 18±16 min) .VTs were terminated by ventricular programmed stimulation and cardioversion.Atr ioventricular (AV) dissociation were observed in 10 of 16 VTs and 1∶1 VA conduc tion were found in 6 of 16.Conclusion:A closed chest pig model of aneurysm afte r AMI using balloon occlusion LAD is feasible and has a relatively high ind uction rate and a low mortality.SMVT of animal model can be induced by programme d stimulation in a relative long period.[ Chinese Journal of Cardiac Pacing an d Electrophysiology, 2003,17(1):52～56]