犬左上肺静脉电传导的特性  

The characters of electric conduction in canine left superior pulmonary veins

作　　者：刘雄涛[1] 郑强荪[1] 卢延生[1] 洪昌明[1] 何勇[1] 张录兴[1] 

机构地区：[1]第四军医大学唐都医院心内科,陕西西安710038

出　　处：《心脏杂志》2008年第4期417-419,427,共4页Chinese Heart Journal

基　　金：军队"十五"卫生科研基金项目资助(01MB126)

摘　　要：目的研究肺静脉电传导的特性,探讨肺静脉异位兴奋灶诱发心房纤颤的具体机制。方法选用25只犬,将自制的18导联环状标测电极置于左上肺静脉外膜上,从左心房、冠状窦远端、肺静脉远端采取S1S1、S1S2两种刺激方案,记录肺静脉18导联外膜标测电图。结果肺静脉内存在类文氏和类莫氏传导阻滞和肺静脉-左心房传导速度逐渐加快电生理现象,后一现象发生在房颤启动前,导致短配对间期或短长周期的心房激动;电活动从心房向肺静脉远端传导时肺静脉各个部位激动较一致,而电活动从肺静脉远端向心房传导时肺静脉各个部位激动不一致;肺房传导时间显著长于房肺传导时间[(46.6±14.4)msvs(17.8±9.3)ms,P<0.01]。结论正常肺静脉具有传导阻滞、传导延迟及各向异性传导的特性,有利于肺静脉内折返的形成;而肺静脉异位兴奋灶快速电活动使肺静脉和心房发生电重构,导致肺静脉-左心房传导速度逐渐加快,最终诱发出心房纤颤。AIM To study the characters of electric conduction in pulmonary veins and then to better understand the electrophysiological mechanism of focal atrial fibrillation （ FAF ） originating from the pulmonary veins. METHODS Twenty-two dogs were used in this study. We placed the annular measuring electrode in the adventitia of the left superior pulmonary veins, stimulated the left atria, distal of CS and distal pulmonary veins by S1S1 bursting stimulation and S1S2 program stimulation and recorded the mapping of pulmonary veins. RESULTS Three electrophysiological phenomena were found in the LSPV, conduction blocks： Wenckebach and Mobitz, and conduction acceleration which happened just before AF. Conduction acceleration triggered the short interval and short-long cycle of atrial activation and initiated AF. When electrical impulses propagated from LA to distal of PV, the different regions of PV agitated simultaneously. When electrical impulses propagated from distal of PV to LA, the different regions of PV did not agitate simultaneously. The conduction time from PV to LA was longer than the that fromLAtoPV[（46.6±14.4） msvs （17.8±9.3）ms, P〈0.01）. CONCLUSION The electrical conduction in PV includes conduction blocks, Conduction delay and different anisotropy conduction, which caused micro-reentry in the PV. Sustained rapid electric activity in PV can cause PV-LA conduction acceleration, which is the base of inducing AF, and thus more easily induce atrial fibrillation.

关 键 词：肺静脉 异位兴奋灶 局灶性心房颤动 电重构 

分 类 号：R541.75[医药卫生—心血管疾病]