Mechanism of Atrial Fibrillation Induced in the Left Atrial Volume-load Model

左心房容量负荷模型诱发心房颤动的机制

基本信息

批准号：
13671411
负责人：
NITTA Takashi
金额：
$ 2.24万
依托单位：
Nippon Medical School
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13671411/
关键词：
atrial fibrillation left atrium volume load pulmonary vein 電気生理高頻度刺激

项目摘要

A new experimental model for atrial fibrillation was established and serial changes in the left atrial volume and atrial electrophysiologies were examined in 10 mongrel canines. The canines underwent a left subclavian artery to pulmonary artery shunt surgery through a left thoracotomy. Left atrial rapid pacing at a cycle length of 100 ma was started 1 week after the shunt surgery.All the animals exhibited progressive dilatation of the left atrium and developed severe heart failure. Three of 10 died in the early postoperative days and 1 developed pacing failure. Remaining 6 animals were subjected to the analysis.A brief period of repetitive activations were observed after a temporal suspension of the rapid pacing one week after the pacing. The duration of repetitive activation prolonged over time and all the animals developed persistent atrial fibrillation (>10 minutes) 4 weeks after the pacing. Atrial fibrillation intervals recorded at both atrial appendages were progressively shortened and the interval in the left atrial appendage was always shorter than at the right appendage. Epicardial mapping of the persistent atrial fibrillation revealed concurrent repetitive activations arising from the right and left superior pulmonary veins that conducted toward the right atrium with progressive conduction delay.A volume load of the LA may provoke repetitive activations in the pulmonary veins and electrical remodeling of the atrial myocardium, and further facilitate the perpetuation of atrial fibrillation. This clinically relevant model of persistent AF associated with a Volume-loaded LA would be useful in examining the electrophysiology of AF and the effects of non-pharmacological therapies.

建立了新的心房颤动实验模型，并检查了 10 只杂种犬的左心房体积和心房电生理的一系列变化。这些犬科动物通过左胸廓切开术接受了左锁骨下动脉至肺动脉分流手术。分流手术后1周开始左心房快速起搏，周期长度为100ma。所有动物均表现出左心房进行性扩张并出现严重心力衰竭。 10 人中有 3 人在术后早期死亡，1 人出现起搏失败。其余6只动物接受分析。起搏一周后暂时暂停快速起搏后观察到短暂的重复激活。重复激活的持续时间随着时间的推移而延长，并且所有动物在起搏后 4 周出现持续性心房颤动（>10 分钟）。两个心耳记录的房颤间隔逐渐缩短，左心耳的间隔总是短于右心耳的间隔。持续性心房颤动的心外膜标测显示，左右上肺静脉并发重复激活，这些激活向右心房传导，并伴有渐进性传导延迟。左心房的容量负荷可能会引起肺静脉的重复激活和肺静脉的电重塑。心房肌，进一步促进心房颤动的持续存在。这种与容量负荷 LA 相关的持续性 AF 的临床相关模型将有助于检查 AF 的电生理学和非药物治疗的效果。