与Cibenzoline转复山羊持续性心房颤动相关的电生理现象分析

The electrophysiological phenomena associated with Cibenzoline-induced termination of atrial fibrillation in the goat

目的 :在持续性心房颤动 (房颤 )山羊模型上 ,分析 类抗心律失常药 Cibenzoline使房颤转复为窦性心律时出现的电生理现象 ,探讨房颤转复的机制。方法 :给 7只山羊的左心房游离壁、左心耳、Bachmann氏束 ( BB)、右心耳及右心房游离壁缝合心外膜电极。用自动房颤刺激器维持房颤 ,待房颤持续 4周后 ,静脉滴注 Cibenzoline( 0 .1mg·kg-1· min-1 ) ,直至房颤终止。分析房颤转复前单极电图的形态特点、房颤周长 ( AFCL)的变化 ,并通过测量房颤周长的标准差 ( AFCLSD) ,分析心房激动均一性变化。结果 :在房颤转复前最后 2次心搏的平均 AFCL有跳跃性延长( P<0 .0 5 ) ,正常电位的百分率显著增加 ( P<0 .0 5 )。房颤转复前最后 1个 AFCLSD在除 BB外的心房各部位内明显缩小 ( P<0 .0 5 ) ,在整个心房内的变化不显著。结论 :在房颤转复前的最后 2次激动 ,房颤波激动的规律性明显增加 ,支持

AIM:To investigate the electrophysiological phenomena associated with atrial fibrillation(AF) cardioversion by Cibenzoline in the goat,and try to explore the mechanism of AF termination by class I durgs. METHODS:Seven goats were chronically instrumented with epicardial electrodes in left atrium(LA),left atrial appendage(LAA),Bachmann's bundle(BB),right atrial appendage(RA) and right atrium(RA). Persistent AF was induced by an automatic atrial fibrillator. After AF persisted for 4 weeks,Cibenzoline(0.1 mg·kg -1 ·min -1 ) was infused until AF terminated. The percentage of normal potentials and AF cycle length (AFCL) in the last 30 beats before cardioversion were evaluated. The standard deviation of AFCL(AFCL SD ) in the last 10 beats were compared intrarregionally and interregionally.RESULTS:Compared with previous beats,in the last 2 AF beats there were dramatic prolongation of AFCLs and increase of narmal potentials( P <0.05). Except for BB,the standard deviation of the last AFCL dectreased regionally( P <0.05),but there was no significant change interrgionally( P >0.05). CONCLUSION:In the last 2 beats before cardioversion,the activation of AF wavelets became highly organized,which may support the hypothesis that the termination of AF by class I drugs is caused by prolonging the excitable period.