左侧星状神经节化学消融对犬急性心肌梗死后室性心律失常的影响

Effect of Chemical Ablation of Left Stellate Ganglion on Ventricular Arrhythmias after Acute Myocardial Infarction in Dogs

目的观察左侧星状神经节(LSG)内微量注射树脂胶毒素(RTX)对犬急性心肌梗死(AMI)后室性心律失常(VAs)的影响。方法28只成年雄性比格犬随机分成对照组(8只)、AM1组(11只)和LSC化学消融组(RTX组,9只)。RTX组犬LSG内做量注射RTX,AMI组和对照组LSG内微量注射不含RTX的溶剂。微量注射RTX或溶剂1h后,RTX组和AMI组通过结扎冠状动脉左前降支建立AMI模型,对照组只分离穿线,不结扎冠状动脉。记录结扎冠状动脉后1hVAs发生情况,随后测量心室有效不应期(ERP)和动作电位时程(APD),对照组于相应时间点测量。通过不同的电压刺激LSC观察犬血压变化来评估LSG功能。结果LSG内注射RTX可显著抑制AMI后VAs发生。与对照组比较,RTX微量注射显著延长心室ERP和APD。与对照组比较,AMI增加LSG神经功能,降低左心室缺血区域的ERP和APD,增加ERP离散度及APD离散度,而LSG内注射RTX可抑制这些变化。结论LSG内微量注射RTX化学消融LSC中表达TRPV-1/TH的交感神经纤维能显著抑制LSG功能,改善AMI后心脏电生理不稳定性,以减少AM1后VAs。

Objective To observe the effect of microinjection of resiniferatoxin(RTX)in left stellate ganglion(LSG)on ventricular arrhythmia(VAs)after acute myocardial infarction(AMI)in dogs.Methods Twenty-eight anesthetized beagles were assigned to the control group(n=8),AMI group(n=11)and left stellate ganglion(LSG)chemical ablation group(RTX group,n=9)in a random manner.The LSG of the RTX group was given a micro injection of RTX,while the AMI group and control group were given a micro injection of LSG without RTX.After the micro injection for 1 hour,the RTX group and AMI group established AMI models by ligating the left anterior descending branch of the coronary artery,while the control group only separated and threaded the coronary artery without ligation.V As were analyzed by continuous ECG recorded for 1 hour;Subsequently,measures of ventricular effective refractory(ERP),monophasic action potentials(MAP)and action potential duration(APD)were assessed.The control group was detected at corresponding time points.LSG function was evaluated by stimulating the LSG at different voltages and observing the changes in blood pressure.Results RTX injection into LSG can significantly inhibit the AMI-induced VAs.Compared with control group,RTX extended the ventricular ERP and APD.Compared with control group,AMI enhances the LSG function,reduce the ischemia area of ERP and the APD,increase ERP dispersion and APD dispersion,while RTX injection in LSG inhibited these changes.Conclusion Chemical ablation of TRPV-1/TH positive sympathetic neurons induced by RTX LSG microinjection could suppress LSG function and improve cardiac electrophysiology instability to protect against AMI-induced VAs.