中文摘要：

目的前期研究已证实刺激Marshall韧带（LOM）远段（含交感神经成分）会导致室性心律，人常的发生。本研究拟在氯化铯（CsCl）诱导的获得性长QT综合征犬模型中探讨选择性消融LOM远段对窒性心律失常的影响。方法第1部分：8只成年健康雄性犬，在消融前后分别刺激LOM远段和左侧星状神经节（LSG），记录血压和心室有效不应期（ERP）的变化。第2部分：将24只犬随机分为3组，每组8只：1组，静注CsCl构建长QT模型；2组，静注CsCl同时刺激星状神经节；3组，消融LOM后静注CsCl同时刺激星状神经节。比较各组问早期后除极（EAD）幅度、室性心律失常的频率和CsCl诱发心动过速的浓度阈值。结果第1部分中，消融前刺激LOM远段和LSG均引起血压升高和心室ERP缩短，但消融后血压升高和ERP缩短的幅度较消融前显著减小。第2部分中，与1组相比，2组的室性心律失常的发生频率和EAD幅度均显著增加，3组无显著增加。此外，2组中CsCl诱发室性心动过速的阈值（0．625mmol／kg）显著低于1组（1．000mmol／kg，P〈0．05）和3组（1．000mmol／kg，P〈0．05）。结论消融LOM远段能够抑制获得性长QT综合征模型室性心律失常的发生，而其抗心律失常的可能机制为阻断了LSG与心室之间的交感神经通路。

英文摘要：

Objective Previous studies have demonstrated that selective stimulation of sympathetic el- ements of ligament of Marshall（LOM） ,the distal segment of LOM that extends towards the left superior pulmo- nary vein（ LOMtspv ）, might induce ventricular arrhythmia（VA）. The present study aimed to investigate the effect of selective ablation of LOMLsPv on VA. Methods In protocol 1,the blood pressure （BP） and ventricular effective refractory period（ERP） change as response to LOMLsPV stimulation and left stellate ganglion（LSG） stimulation were measured before and after LOMtspv ablation in 8 anesthetized dogs.In protocol 2,24 dogs were randomly divided into group 1 （ received CsC1 alone, n = 8 ） , group 2 （ CsCI combined with LSG stimulation, n = 8 ） and group 3 （ CsC1 combined with LSG stimulation after LOMLsPv ablation, n = 8 ）. Early after-depolarization （EAD） amplitude, VA prevalence and the tachycardia threshold（ measured according to the dose of CsC1 ad- ministered）were compared among the three groups. Results In protocol 1, both LOMLsPV stimulation and LSG stimulation significantly increased BP and shortened ventricular ERP, both of which were significantly at- tenuated by LOMLsPV ablation. In protocol 2, compared with group 1, the prevalence of VA and EAD ampli- tudes were significantly augmented in group 2 and were maintained at a comparable level in group 3. Fur- thermore, the tachycardia threshold in group 2（0.625 mmol/kg）was significantly lower than that noted in group 1 and group 3 （ both 1.000 mmol/kg, P〈0.05 ）. Conclusion LOMLspv ablation reduces the prevalence of VA induced by CsCl in combination with LSG stimulation in acquired long QT model, and the antiarrhythmic effect may involve the hlockade of the sympathetic conduit between LSG and ventricles.