高频刺激右心耳引起家兔慢性心房颤动

目的 探讨以高频率起搏刺激右心耳建立家兔慢性心房颤动模型的方法.方法 20只家兔随机分为实验组及对照组,对照组为假手术组.植入起搏电极但不起搏;实验组10只家兔予开胸植入双极电极并予以(800次/min)刺激右心耳30d,4h/d,术后定期监测起搏、心房颤动的发生情况,同时测定起搏前及房颤发生后心房有效不应期(AERP)的变化.结果 实验组均完成了实验,术后第7d,7只(70%),兔发生了房颤,2周时共有8只(80%)发生了房颤并能稳定维持(与对照组比较,P<0.01),30 d时仍示房颤,其余2只兔至30d时仍呈起搏心律;对照组则未发生任何心律失常情况.AERP缩短,AERP频率适应不良,与基础状态相比有显著意义.结论 长期高频率起搏刺激家兔右心耳是建立慢性房颤模型的有效方法.

Establishment of a rabbit chronic atrial fibrillation model with long - term rapid atrial stimulation

Objective To investigate the possibility of establishing a chronic atrial fibrillation model with long - term rapid atrial stimulation(800 beats/min), which was performed in rabbits in vivo.Methods Rabbits were received electrical stimulation through bipolar atrial epicardial lead by surgical technique,RAP 800bpm was used to induce AF,20 rabbits were randomly divided into 2 groups :(1)control group(n=10): electrode was implanted but no pacing;(2)experimental group (n =10):a right intercostal thoracotomy was performed and the pericardium was opened to expose the heart and a bipolar steel-wire pacing electrode was fixed on the epicardium of the right atria in 10 rabbits.Then the rapid pulse generator was connected with the outlet of the electrode and rapid atrial pacing (800 bpm,4 hours/day)was initiated and continued for 30 days.Electrocardiogram (ECG) was monitored and recorded on day 1,3,5,7,14,21 and 30.The atrial effective refractory period (AERP) was measured before pacing and at the time of fibrillation.Results On day 14,atrial fibrillation was developed in 8 rabbits (80%)and sustained at least till to day 30 (P<0.01).There was no atrial fibrillation occurred in control group. The ventricular rate of atrial fibrillation was fast initially(P<0.05)and decreased gradually later (P<0.05).The AERP was shortened and the rate adaptation of AERP was lost when atrial fibrillation occurred.Conclusion Long - term interrupted rapid right atria stimulating is an effective method in the establishment of a chronic atrial fibrillation model in rabbits.