Liu Xudong, Sun Lin, Chen Jugang, Jin Yingying, Liu Qing, Xia Zhongnan, Wang Liang, Li Jingjie
Department of Cardiology, The First Affiliated Hospital of Harbin Medical University, Heilongjiang Province, Harbin city, PR China.
Department of Cardiology, The First Affiliated Hospital of Xingxiang Medical University, Henan Province, Xinxiang city, PR China.
PLoS One. 2017 Jul 21;12(7):e0181322. doi: 10.1371/journal.pone.0181322. eCollection 2017.
Modulation of the autonomic nervous system (ANS) has already been demonstrated to display antiarrhythmic effects in patients and animals with MI. In this study, we investigated whether local cardiac denervation has any beneficial effects on ventricular electrical stability and cardiac function in the chronic phase of MI.
Twenty-one anesthetized dogs were randomly assigned into the sham-operated, MI and MI-ablation groups, respectively. Four weeks after local cardiac denervation, LSG stimulation was used to induce VPCs and VAs. The ventricular fibrillation threshold (VFT) and the incidence of inducible VPCs were measured with electrophysiological protocol. Cardiac innervation was determined with immunohistochemical staining of growth associated protein-43 (GAP43) and tyrosine hydroxylase (TH). The global cardiac and regional ventricular function was evaluated with doppler echocardiography in this study.
Four weeks after operation, the incidence of inducible VPC and VF in MI-ablation group were significantly reduced compared to the MI dogs (p<0.05). Moreover, local cardiac denervation significantly improved VFT in the infarcted border zone (p<0.05). The densities of GAP43 and TH-positive nerve fibers in the infarcted border zone in the MI-ablation group were lower than those in the MI group (p<0.05). However, the local cardiac denervation did not significantly improve cardiac function in the chronic phase of MI, determined by the left ventricle diameter (LV), left atrial diameter (LA), ejection fraction (EF).
Summarily, in the chronic phase of MI, local cardiac denervation reduces the ventricular electrical instability, and attenuates spatial heterogeneity of sympathetic nerve reconstruction. Our study suggests that this methodology might decrease malignant ventricular arrhythmia in chronic MI, and has a great potential for clinical application.
自主神经系统（ANS）的调节已被证明在心肌梗死患者和动物中具有抗心律失常作用。在本研究中，我们调查了局部心脏去神经支配对心肌梗死慢性期心室电稳定性和心脏功能是否有任何有益影响。
21只麻醉犬被随机分为假手术组、心肌梗死组和心肌梗死消融组。局部心脏去神经支配4周后，使用左星状神经节（LSG）刺激诱发室性早搏（VPCs）和室性心律失常（VAs）。采用电生理方案测量心室颤动阈值（VFT）和可诱导VPCs的发生率。通过生长相关蛋白-43（GAP43）和酪氨酸羟化酶（TH）的免疫组织化学染色确定心脏神经支配情况。本研究采用多普勒超声心动图评估整体心脏和局部心室功能。
术后4周，与心肌梗死犬相比，心肌梗死消融组可诱导VPC和室颤的发生率显著降低（p<0.05）。此外，局部心脏去神经支配显著改善了梗死边缘区的VFT（p<0.05）。心肌梗死消融组梗死边缘区GAP43和TH阳性神经纤维密度低于心肌梗死组（p<0.05）。然而，通过左心室直径（LV）、左心房直径（LA）、射血分数（EF）确定，局部心脏去神经支配在心肌梗死慢性期并未显著改善心脏功能。
总之，在心肌梗死慢性期，局部心脏去神经支配可降低心室电不稳定性，并减弱交感神经重建的空间异质性。我们的研究表明，这种方法可能会减少慢性心肌梗死中的恶性室性心律失常，具有很大的临床应用潜力。
