猪慢性缺血心肌内注射PcDNA_(3.1)VEGF_(165)对心电稳定性的影响

Effect of PcDNA_(3.1) VEGF_(165) Injected Into Chronic Ischemic Myocardium on the Ventricular Electrical Stability in Pig.

探讨猪慢性缺血心肌内注射PcDNA3 .1VEGF165(血管内皮生长因子 )后 ,在心肌血供改善的基础上 ,缺血心肌的电稳定性能否随缺血的改善而有所改善。用Ameroid收缩环制备猪慢性心肌缺血模型 ,在其右室心尖部及流出道行心内程序电刺激 ,检测室性心动过速 (VT)、心室颤动 (VF)的诱发率 ,并测定左室室壁运动功能和心肌血管密度 ,比较VEGF基因治疗组与病理对照组间的差异。结果 :在对照组 10例中 ,2例诱发出单形性持续性VT ,2例诱发出多形性VT(持续 10s左右转为VF) ,2例诱发出VF ,恶性心律失常诱发率 6 0 %。治疗组 12例中 ,1例诱发出VF ,1例诱发出多形性VT(持续数秒后转为VF) ,恶性心律失常诱发率 17%。基因治疗组缺血区室壁运动和心肌血管密度明显优于病理对照组 ,两组间存在显著差异。结论 :慢性缺血心肌内注射PcDNA3 .1VEGF165基因不仅可增加心肌供血、改善心肌功能 ,而且可能在此基础上提高心电稳定性 。

Department of Cardiology,Tongji Hospital,Tongji Medical College,Huazhong University of Science and Technology,Wuhan 430022,ChinaTo compare the electrical stability of ischemic ventricular myocardium in pigs with or without PcDNA 3.1 VEGF 165 local treatment.The Ameroid constriction rings were placed on the LCX to induce chronic coronary stenosis in 22 pigs.Among them 12 pigs,with PcDNA 3.1 VEGF 165 injected directly into ventricular ischemic area,designed as gene therapy group,10 pigs treated as control group.Multi step programmed electrical stimulation were performed in right ventricular apex and outflow tract in all pigs.The incidence of VT and VF,capillary density and contractility of the ischemic zone were compared between the gene therapy group and control group.In the control group( n =10),mono morphic sustained ventricular tachycardia(VT) were induced in 2 pigs,poly morphic VT were induced and turn to ventricular fibrillation(VF) after several seconds in 2 pigs,VF were induced in 2 pigs,no VF or VT appeared in other 4 pigs at the endpoint of the programmed electrical stimulation,the incidence of malignance arrhythmia was 60%.In the gene therapy group( n =12),VF was induced in 1 pig,poly morphic VT was induced in 1 pig,the incidence of malignance arrhythmia was 17%.The difference of the incidence between the two groups are significant( P <0.01).Meanwhile,the capillary proliferation and contractility of the ischemic zone in gene therapy group were also significantly better than that in control group( P <0.01).PcDNA 3.1 VEGF 165 gene injected directly into ventricular ischemic zone not only improve the capillary density and contractility of the ischemic myocardium but also improve the ventricular electrical stability,and thus may decrease the incidence of VT and VF in coronary heart desease.