The Study Of The Preventive And Therapeutic Effects Of Fastigial Nucleus Stimulation On Atrial Fibrillation In Dogs

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 groupsâ‘ AF group: 5 dogs were treated with the stimulus of electricity to CVN and burst stimulation to atrium;â‘¡FNS 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;â‘¢sham 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.