犬急性阈上迷走神经刺激介导型心房纤颤模型心房重构的变化

Atrial remodeling in canine with acute suprathreshold vagal stimulation mediated atrial fibrillation

目的对比2种非瓣膜病变急性房颤模型中心房肌电生理、结构指标、神经指标的变化,了解最佳模拟急性房颤模型心房重构的方法。方法 13只比格犬,随机分为2组,GroupI为心房快速起搏(rapid atria pacing,RAP)6h组,GroupII为RAP+迷走神经刺激(vagal nerve stimulation,VNS)6h组,2组均在1、3、6h后给予测量心房肌单相动作电位(monophasic action potential,MAP)、房颤诱发率;实验结束后取标本测量2组马松染色(MASSON染色)、糖原染色(PAS染色)、神经指标的变化。结果 2组心房肌MAP随着心房快速起搏时间的延长,出现振幅减小、时限缩短的趋势。2组房颤诱发率以GroupII为高。2组心房糖原染色、神经丛中酪氨酸羟化酶(Tyrosine hydroxylase,TH)和胆碱乙酰转氨酶(Choline acetyl transaminase,CHAT)染色和定量差异均有统计学意义(P均<0.05)。结论阈上迷走神经刺激的介入加剧心房重构的恶化,使用心房快速起搏+迷走神经刺激建立的房颤模型成功率高、周期短、重复性强,同时也为研究迷走神经在房颤发病及治疗中的地位和作用提供了重要的研究基础。

Objective To compare the changes of atrial remodeling values in the two types of acute atrial fibrillation（AF）models and thereby discuss the best models to imitate acute AF.Methods Thirteen adult Beagles were randomly allotted to two groups,Group I（n =6）underwent 6 hrapid atrial pacing（RAP）only;Group II（n =7）underwent 6 hvagal nerve stimulation（VNS）plus RAP.Monophasic action potential（MAP）,AF induction rate and other remodeling values were assessed.Results The MAP of atrial muscle extended along with the time,action potential duration（APD）occurred and there was a significant tendency of APD90 shrinking.Nevertheless,the inducing rate of AF in the Group II interference was higher in these two groups.Abnormal results were found in the two groups of atrial glycogen staining,tyrosine hydroxylase（TH）and choline acetyl transaminase（CHAT）staining and quantitative analysis of ganglionic plexus.Conclusion The AF model established on the basis of VNS＋RAP is more reliable with high success rate and strong repeatability.At the same time,for the study of the vagal nerve in the role of the pathogenesis and treatment of AF,it provides important studying foundation.