|Budget Amount *help
¥3,500,000 (Direct Cost : ¥3,500,000)
Fiscal Year 1998 : ¥400,000 (Direct Cost : ¥400,000)
Fiscal Year 1997 : ¥3,100,000 (Direct Cost : ¥3,100,000)
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.
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.
The 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