腔内右心房直接快速起搏建立犬急性房颤模型的研究

摘要

目的 探讨腔内右心房直接快速起搏建立犬急性房颤模型的可行性.方法 成年健康中华田园犬12只,随机分为2组:假手术组(Sham,S)、起搏组(Pacing,P).实验2组均通过股静脉穿刺直接放置起搏电极至右心房,S组不起搏,P组给予600次/min的快速右心房起搏10h.每小时测量心房有效不应期(Atrial effective refractory period,AERP)时限及Burst刺激诱发心房颤动(Atrial fibrillation,AF)的频率及持续时间.实验结束后开胸取右心房组织,HE染色观察心肌结构变化.结果 实验结束后,与S组比较,P组AERP平均缩短(18.83±3.65ms),差异有统计学意义(P<0.01);S组与P组诱发AF的总次数及频率分别为[14(2.3%)]vs.[128(21.3%)],差异有统计学意义(P<0.01);S组与P组诱发AF的时间分别为(53.66±23.97)s vs.(1763.66±441.23)s,差异有统计学意义(P<0.01).HE染色:S组右心房心肌细胞排列整齐,P组心肌细胞排列紊乱、间质增生明显、轻度纤维增生并见少量炎症细胞浸润.结论 经腔内右心房直接快速起搏建立犬急性房颤模型成功率高,重复性好,是建立动物急性AF模型的有效方法.%Objective To investigate the feasibility of establishing acute atrial fibrillation model in dogs by direct rapid pacing of intracavitary right atrium. Methods 12 adult healthy Chinese pastoral dogs were randomly divided into two groups:sham-operated group( Sham,S) and pacing group( Pacing,P) . Pacing electrodes were placed directly to the right atrium by femoral vein puncture in both groups. Group S did not receive pacing,while group P was given 600 times /min fast right atrial pacing for 10h. The duration of atrial effective refractory period(AERP)and the frequency and duration of atrial fibrillation(AF)induced by Burst stimulation were measured every hour. At the end of the experiment,the tissue of right atrium was taken by thoracotomy to ob-serve the changes of myocardial structure by HE staining. Results After the experiment,compared with group S,the average short-ening of AERP in group P was(18. 83 ± 3. 65ms),and the difference was statistically significant(P<0. 01);The total number and frequency of AF induction in group S and group P were[14(2. 3%)]vs. [128(21. 3%)]respectively,statistically significant(P<0. 01);The time of AF induction in group S and group P were(53. 66 ± 23. 97)s vs. (1763. 66 ± 441. 23)s respectively,statistical-ly significant(P<0. 01). HE staining:the right atrial cardiomyocytes in group S were arranged neatly,while in group P,the ar-rangement of cardiac myocytes was disordered,interstitial hyperplasia was obvious,mild fibrous hyperplasia and a small amount of inflammatory cell infiltration was observed. Conclusion The model of acute atrial fibrillation in dogs established by direct rapid pacing of intracavitary right atrium has high success rate and good reproducibility,which is an effective method to establish animal acute AF model.