The effect of pulmonary isolation on the initiation and sustenance of atrial fibrillation induced in left atrial, volume-load model

采用犬左心房容量负荷模型，研究肺隔离对心房颤动发生和维持的影响。在杂种犬左锁骨下动脉和左肺动脉之间进行分流。所有动物术后均出现严重心力衰竭。一些动物死于严重的心力衰竭。分流术后一周开始左心耳快速起搏。对存活4周的动物进行肺静脉标测，所有动物均出现持续性房颤。左房肌电周期短于右房肌电。周期长度在4周内逐渐缩短。心房颤动时的心房激动图显示来自左右肺上静脉的重复激动和至右心房的纤颤传导。采用双极射频消融器进行肺静脉隔离。在左房容量负荷模型中，除肺静脉的重复激活外，心房折返性激活或非肺静脉异常激活可能在房颤的维持中起作用。

Effect of pulmonary isolation on the initiation and sustenance of atrial fibrillation was studied in canine left atrial volume-load model. A shunt was made between the left subclavian artery and the left pulmonary artery in mongrel dogs. All the animals exhibited severe heart failure postoperatively. Some animals died of severe heart failure. Rapid pacing at the left atrial appendage was initiated one week after the shunt surgery. The animals survived for 4 weeks were subjected to the pulmonary vein mapping study.Continuous atrial fibrillation was observed in all animals. The cycle length of the left atrial electrograms was shorter than that of the right atrial electrograms. The cycle length progressively shortened during the 4 weeks. Atrial activation maps during atrial fibrillation showed repetitive activation originated from the right and left superior pulmonary veins and fibrillatory conduction to the right atrium. Pulmonary vein isolation was performed by means of bipolar radiofrequency ablation device. Atrial fibrillation was not terminated in any animals.In addition to the repetitive activation in the pulmonary veins, atrial reentrant activations or non-pulmonary vein abnormal activations might have played a role in the sustenance of atrial fibrillation in the left atrial volume-load model.