Impact of High Thoracic Epidural Blockade on Autonomic Nerve Remodeling in Experimental Dogs With Atrial Fibrillation / 中国循环杂志

ABSTRACT

Objective: To observe the impact of high thoracic epidural blockade (HTEB) on atrial autonomic nerve remodeling in dogs with atrial ifbrillation (AF) induced by long-term rapid right atrial appendage pacing and to explore the effect of nerve growth factor (NGF) on atrial autonomic nerve remodeling. 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 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.