Usefulness of catheter ablation for atrial fivrillation

我们尝试用导管消融在心房形成类似迷宫的线性病变，以恢复慢性心房颤动的窦性心律。将电极插入心房内的颈静脉固定，并在颈部植入高频起搏器以诱发持续性心房颤动。持续间隔刺激5s，持续2~4周，制成持续性房颤犬。射频能量以Amazr导管(7F，四极(7 mm线圈，电极间距1.25 mm)，60度热控)作为消融导管，持续60s。采用美敦力公司生产的ATACKER作为高频发生器。分别对右心房和左心房进行线性消融。结果：1.Amazr导管消融病变：电极两端消融病变较宽，且侵袭深度加深，消融病变随电极中心位置的增大而减轻。Cathet…对于心房颤动，采用逐点消融的方法进行消融，使导管逐渐移动。实验初期尝试了上腔静脉-下腔静脉、下腔静脉-三尖瓣、房间隔-右房游离壁-三尖瓣的线性损毁，消融后诱发房颤。因此，右心房的线状病变判断其对高频刺激所致持续性房颤的疗效不是很好。然后，分离左房肺静脉周长和肺静脉周围区域进行消融。但消融后仍可诱发心房颤动。心内膜侧无血栓形成，也可识别出跨壁损伤的部位，并证实其安全性。然而，很难线性地使跨壁损伤成为电传导中断所必需的，而且心内膜侧正常保留的位置也被识别出来。讨论心外膜侧在心跳下可能无法获得充分的病变，即使是以线性病变准备为目的的导管也是如此。导管消融迷宫手术难度较大。较少

We tried to form linear lesion at atrium like MAZE operation using catheter ablation to restore sinus rhythm from chronic atrial fibrillation experimentally. The electrode was fixed from the jugular vein in atrium by insertion, and the high-frequent pacemaker was implanted in the cervix in order to induce persistent atria fibrillation. Keeping interval stimulation of the 5 seconds for the 2-4 week made the persistent atrial fibrillation dog. RF energy was delivered for 60 seconds using the Amazr catheter of 7F, quadrupoles (7mm coil, 1.25mm distance between electrodes) in the thermal control of 60 degrees as a catheter for the ablation. Atacker made by Medtronic Co. was used as a high frequency generator. The linear ablation was performed to the right atrium and left atrium side.1. Ablation lesion by the Amazr catheter.The ablation lesion was wide in the double end of the electrode, and the invasion depth deepened, and the ablation lesion was reduced with the electrode center.2. Cathet … More er ablation for atrial fibrillation.The linear lesion was made by the point-by-point method in which the catheter gradually moved. Though the linear lesion of superior vena cava-inferior vena cava, inferior vena cava-tricuspid valve, atrial septum-right atrium free wall-tricuspid valve was tried in the experiment initial stage, the atrial fibrillation was induced after the ablation. Therefore, the linear lesion in the right atrium side judged that it was not very effective in persistent atrial fibrillation induced by the high-frequent stimulation. Then, the ablation in which left atrial pulmonary vein circumference and region surrounded in the pulmonary vein were isolated was performed. However, the atrium fibrillation was still induced after the ablation. There was no thrombogenesis in the endocardium side and the position where the transmural lesion was obtained was also recognized, and the safety was confirmed. However, it was difficult to linearly make the transmural lesion necessary for the disruption of the electrical conduction, and the position where the endocardium side normally remained was also recognized.3. DiscussionThe sufficient lesion might not be obtained under the heartbeat from the epicardium side, even if it is a catheter made with the linear lesion preparation purpose. The MAZE operation by catheter ablation seemed to be difficult. Less