高位胸段硬膜外阻滞对心房颤动自主神经重构的影响

2017-01-07曹勇田晓燕张苒代玉川赵家琦安毅

中国循环杂志 2016年12期

关键词：手术

曹勇，田晓燕，张苒，代玉川，赵家琦，安毅

高位胸段硬膜外阻滞对心房颤动自主神经重构的影响

曹勇*，田晓燕，张苒，代玉川，赵家琦，安毅

目的：观察高位胸段硬膜外阻滞（HTEB）对长期右心耳快速起搏诱发心房颤动（房颤）犬心房自主神经重构的影响，并探讨心房肌神经生长因子（NGF）在心房自主神经重构中的作用。

心房颤动；自主神经重构;注射，硬膜外；利多卡因

Methods: AF model was established by consistent rapid atrial pacing for 6 weeks. 18 experimental dogs were randomly divided into 3 groups: Sham group, the dogs had no pacing while received normal saline injection; Control group, the dogs had pacing and normal saline injection; HTEB group, the dogs had pacing and 0.5% lidocaine injection for HTEB. n=6 in each group. Atrial myocardium collagen volume fraction (CVF) was examined by Masson staining; sprouting of NGF related protein 43 (GAP43) and tyrosine hydroxylase (TH) were assessed by immunohistochemistry; protein expressions of NGF, GAP43 and TH were measured by Western blot analysis.

Results: Compared with Sham group, HTEB group showed decreased CVF and sprouting of GAP43, TH, P＜0.05; reduced protein expressions of NGF, GAP43 and TH, P＜0.05-0.01. Compared with Sham group, HTEB group presented increased CVF and sprouting of GAP43, TH, P＜0.05-0.01; elevated protein expressions of NGF, GAP43 and TH, P＜0.05.

Conclusion: Long-term rapid atrial pacing induced AF dog had inhomogeneous sprouting of atrial myocardial nerve which may cause autonomic nerve remodeling; NGF played the important role in such process. HTEB could effectively inhibit NGF up-regulation and suppress the autonomic nerve remodeling in experimental dogs.

Key wordsAtrial fbrillation; Autonomic nerve remodeling; Injection, epidural; Lidocaine

(Chinese Circulation Journal, 2016,31:1219.)

心房颤动（房颤）的发生机制至今仍未明确，目前认为房颤是多种机制共同作用的结果。心房重构作为房颤的发生机制之一已经获得公认，房颤时心房重构主要包括：电重构、结构重构和收缩功能重构。新近研究表明，除上述三种重构外，房颤时心房还存在“自主神经重构”，主要表现为自主神经纤维的显著萌出及其不均一性分布[1]。“自主神经重构”可通过多种机制触发并维持房颤。因而，有人提出房颤发生的“自主神经机制”。另外，研究发现[2]，高位胸段硬膜外阻滞（HTEB）可通过抑制交感神经系统、血管紧张素系统过度激活，抑制凋亡和氧化应激，可用于治疗顽固性心绞痛和扩张型心肌病,提示HTEB可能通过多种途径影响房颤“自主神经重构”，抑制房颤的发生和维持。本研究旨在观察HTEB对房颤犬心房“自主神经重构”的影响，并探讨心房肌神经生长因子（NGF）在心房自主神经重构中的作用。