心房快速起搏对兔心房颤动心电生理的影响

Influence of rapid atrial pacing on the electrophysiological changes in rats with atrial fibrillation

目的探讨心房快速起搏对兔心房有效不应期(effective refractory period,ERP)和心肌组织场电位时程(field potential duration,FPdur)的影响。方法成年新西兰兔40只,以500次/min行快速起搏并测量ERP,根据起搏时间分为5组,0,4,8,12,24h组各8只。起搏结束时开胸取心,应用微电极阵列技术记录场电位形态及Fpdur,比较各组心房组织FPdur与ERP变化趋势。结果 8h组ERP缩短为(82.11±1.74)ms,24h组缩短至(80.09±2.18)ms,与0h组比较差异均有统计学意义(P<0.05);8h组FPdur延长为(121.18±3.55)ms,24h组延长至(85.91±5.4)ms,与0h组比较差异有统计学意义(P<0.05);R-R间期在起搏4h后缩短至最低,振幅在起搏后12h降至最低,搏动频率在起搏后4h降至最低,与0h组比较差异均有统计学意义(P<0.05)。结论心房颤动时心房ERP缩短,FPdur延长,微电极阵列技术可对心房颤动时的电重构提供准确电生理变化信息。

Objective To study the influence of rapid atrial pacing on effective refractory period（ERP） and the field potential duration（FPdur）.Methods Forty adult New Zealand rabbits were randomly divided into five groups according to the pacing time,0-hour（P0） group,4-hour（P4） group,8-hour（P8） group,12-hour（P12） up and 24-hour（P24） group,with 8 rabbits in each group,after being triggered the rapid atrial pacing by 500 beats/min and measured the ERP.The heart was taken out after pacing was over.The FPdur and the field potential form of the right atrium was mapped with the microelectrode arrays technique.The change tendency of the FPdur and the ERP was analysed and compared.Results ERP began to shorten to（82.11±1.74） ms in P8 group and to（80.09±2.18） ms in P24 group,which had a significant difference compared with that in P0 group（P0.05）.FPdur began to extend to（121.18±3.55） ms in P8 group and to（85.91±5.4） ms in P24 group,which had a significant difference compared with that in P0 group（P0.05）.R-R interval reduced to the minimum after in P4 group,the amplitude reduced to the minimum after in P12,and the frequency of the pacing pulse reduced to the minimum in P4 group,which had a significant difference compared with that in P0 group（P0.05）.Conclusion ERP shortens and FPdur extends during atrial fibrillation in rabbits.Microelectrode arrays technique can be used safely in studying electrical remodeling of atrial fibrillation and may provide accurate information of electrophysiological changes.