论文标题:小脑顶核电刺激对犬心房颤动防治作用的研究
The Study of the Preventive and Therapeutic Effects of Fastigial Nucleus Stimulation on Atrial Fibrillation in Dogs
论文作者
论文导师 张晓刚,论文学位 硕士,论文专业 内科学
论文单位 重庆医科大学,点击次数 84,论文页数 56页File Size6632K
2007-05-01论文网 http://www.lw23.com/lunwen_861480332/
fastigial nucleus stimulation;;vagus nervus;;atrial fibrillation;; atrial remodeling;;dog
目的:探讨小脑顶核仿生波电刺激对心房颤动的防治作用。 方法: (1)采用颈部迷走神经干仿生波刺激+经食道心房猝发刺激建立狗心房颤动的动物模型,用小脑顶核仿生波电刺激的方法来观察其对该动物模型的改善作用。(2)将14只狗随机分为①房颤组(AF组)(n=5):采用仿生波电刺激迷走神经+经食道心房猝发刺激,诱发心房颤动;②小脑顶核刺激组(FNS组)(n=5):在诱发房颤前预先给予小脑顶核仿生波电刺激1小时,然后采用颈部迷走神经干仿生波刺激+经食道心房猝发刺激,诱发心房颤动。连续21天,然后将狗处死。③对照组(Sham组)(n=4):只在颈部埋植电极以及在实验中食道电极猝发刺激,不进行迷走刺激;(3)观察各组房颤诱发次数变化;房颤持续时间的变化;左房容积及射血分数变化;左心房肌细胞胶原纤维含量的改变;左心房肌细胞超微结构改变。 结果:(1)迷走神经刺激+基础刺激成功建立房颤犬动物模型。(2)小脑顶核电刺激可明显降低犬实验性房颤的发生率,及明显降低房颤持续时间(P<0.05)。(3)FNS对左房容积及射血分数的影响:AF组与sham组比较,左房容积增大,射血分数明显减小,差异具有显著性(P<0.05)。FNS组与AF组比较,左房容积减小,射血分数增大,差异具有显著性(P<0.05)。(4)FNS对左心房肌细胞胶原纤维含量的影响:AF组与Sham组比较,左心房肌细胞胶原纤维含量明显增加,差异具有统计学意义(P<0.05);FNS组与AF组比较,左心房肌细胞胶原纤维含量减少,差异具有统计学意义(P<0.05)。(5)FNS对左心房肌细胞超微结构影响:AF组与Sham组比较,AF组肌原纤维排列紊乱,有肌丝溶解现象。线粒体数量明显增多,丛状聚集,并出现空泡、溶解现象,肌原纤维之间线粒体少见,线粒体变长,大小不一。FNS组与AF组比较,上述结构紊乱有所改善。 结论:(1)迷走神经刺激+基础刺激制备房颤动物模型的方法,成功率高、重复性好、模型稳定。该法成功建立房颤动物模型还提示自主神经功能紊乱参与了房颤的发生。(2)小脑顶核仿生电刺激可明显降低犬实验性房颤的发生率,以及明显降低房颤持续时间。(3)小脑顶核仿生电刺激可改善实验性房颤犬心房的重构;可减轻实验性房颤犬左房心肌细胞超微结构的破坏;可减轻实验性房颤犬左房心肌组织中胶原纤维的增生。
OBJECTIVE: To evaluate the preventive and therapeutic effects of the fastigial nucleus stimulation (FNS) on atrial fibrillation(AF). METHODS:(1)AF canine model was established by stimulating the dog’s cervical vagus nerve(CVN) with biological electric current, and stimulating the cardiac atrium by esophagus with burst stimulation, the effects of FNS on AF were observed. (2)14 dogs were randomly divided into three groups①AF group: 5 dogs were treated with the stimulus of electricity to CVN and burst stimulation to atrium;②FNS group: one hour after being pretreated with the FNS the 5 dogs were treated with the stimulus of electricity to vagus nerve and atrium to induce AF for 21 days, and then the dogs were sacrificed;③sham group: 4 dogs were implanted with electrodes into cervical part and treated with burst stimulation from esophagus electrodes, without cervical vagal stimulation(.3)The frequency and the duration of AF, the left atrium volume and the LAEF, and changes of collagen fibers and ultramicrostructure of the left atrium were observed. RESULTS: (1)AF canine model was set up successfully by cervical vagus nerve stimulation and burst stimulation; (2)The influence of FNS on AF:The frequency of AF in FNS group was significantly reduced compared with the AF group. (3)The effect of FNS on left atrium volume and LAEF:Compared with the sham group, left atrium volume in AF group was augmented and LAEF was decreased (p<0.05); left atrium volume of the FNS group was diminished and LAEF was increased compared with the AF group (p<0.05). (4)The effect of FNS on collagen fibers of left atrium: The amount of collagen fibers in left atrium of the AF group was more than that of the sham group(p<0.05),while the amount of the FNS group was less than that of the AF group(p<0.05). (5)The effect of FNS on the ultramicrostructure of left atrium:Compared with the sham group, the left atrium muscle fibril in the AF group arranged disorderly with partially dissolved myofilament; at the same time, the quantity of mitochondria increased: the mitochondria aggregated clusteredly with vacuolus, prolonged shape and various size, while the quantity of mitochondria among the muscle fibrils were decreased; meanwhile, all of that mentioned above in the FNS group were partly improved. CONCLUSION: (1)the method of establishing animal model by cervical vagus nerve stimulation and burst stimulation was easy to achieve and repeat. The successfully establishment of the AF animal model indicated that functional disorder of autonomic nerve had been involved in the generation of AF. (2)FNS could significantly reduce the occurrence and the duration of experimental AF. (3)FNS could ameliorate the auricular reconstruction of experimental AF dogs, lessen the ultrastructural demolishing of atria sinistrum cells, and inhibite the accrementition of collagen fibers in the myocardium tissue of atria sinistrum.
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