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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，观察了10只杂种犬左心房容积和心房电生理的变化。犬通过左开胸行左锁骨下动脉至肺动脉分流手术。分流术后1周开始左心房快速起搏，周期长度为100ma。所有动物均表现出进行性左心房扩张并发展为严重的心力衰竭。10例患者中有3例在术后早期死亡，1例出现起搏衰竭。其余6只动物进行分析。在起搏1周后短暂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，所有动物在起搏后4周发生持续性心房颤动（bbb10分钟）。双耳心房颤动的间隔时间逐渐缩短，左耳心房颤动的间隔时间总是短于右耳。持续性心房颤动的心外膜测图显示，右上肺静脉和左上肺静脉向右心房同时出现重复激活，并伴有进行性传导延迟。大容量负荷的LA可能引起肺静脉的重复激活和心房心肌的电重构，并进一步促进心房颤动的持续。这种与容量负荷型心房纤颤相关的持续性心房纤颤临床相关模型将有助于检查心房纤颤的电生理和非药物治疗的效果。