犬心房神经丛消融对靶心房肌组织超微结构的远期影响

Long-term effects of canine atrial nerve plexus ablation on the ultrastructure of target atrial muscle tissue

目的观察犬心房神经丛消融区靶心房组织超微结构的远期改变,试图为解释临床心房颤动患者远期复发寻求潜在的新线索。方法32只杂种犬随机分为神经丛消融组(n=24)和假手术组(组1,n=8)。神经丛消融组行心脏右上神经丛和右下神经丛消融,术后随机分为3个亚组(2~4组)分别观察1、6、12个月。造模结束后,取靶心房组织利用透射电镜观察靶心房肌组织超微结构的变化。结果消融后1个月,靶心房肌细胞超微结构出现显著异常改变,且这种变化持续到消融后12个月。此外,心肌间质胶原沉积程度随时间延长而增加。结论心房神经丛消融引起的心房去神经化,可引起靶心房组织超微结构的长期损伤及心肌纤维化,此可能为临床解释射频消融术后心房颤动远期复发提供某种潜在的新线索。

Objective To observe the long-term changes in the ultrastructure of the target atrial tissue in the canine atrial plexus ablation zone,and tries to find potential new clues to explain the long-term recurrence of patients with clinical atrial fibrillation.Methods Thirty-two mongrel dogs were randomly divided into ganglionaged plexi(GP)ablation group(n=24)and sham-operated group(group 1,n=8).The GP ablation group was subjected under anterior right ganglionated plexi and inferior right ganglionated plexi ablationand was randomly divided into three subgroups(groups 2-4),which were observed for 1,6 and 12 months after ablation,respectively.Ultrastructural analysis of the target atrial tissue was conducted using an electron microscope.Results Significant ultrastructural abnormalities wasobserved in the myocardial cells of the target tissue at 1 month after ablation,and these abnormalities did not resolve until 12 months after ablation.However,the extent of myocardial interstitial collagen deposition increased over time.Conclusion This study suggests that atrial denervation caused by atrial nerve plexus ablation can cause long-term damage to the ultrastructure of the target atrial tissue and myocardial fibrosis,which may provide some potential new clues for clinical interpretation of the long-term recurrence of atrial fibrillation after radiofrequency ablation.