论文部分内容阅读
目的和方法：本文采用浮置式玻璃微电极记录心肌细胞跨膜动作电位（ＴＡＰ）技术，研究氯化铯（ＣｓＣｌ）诱发的在体家兔早期后除极（ＥＡＤ）和触发电活动（ＴＡ）以及复极离散化程度。结果：ＣｓＣｌ诱发高膜电位水平的ＥＡＤ的配对间期（ＣＩ）较长，其振幅和ＣＩ随刺激周期（ＣＬ）的增加而增加，此种ＥＡＤ及ＴＡ可导致室性早搏（ＶＰＢ）和多形性室速，ＥＡＤ的ＣＩ和ＶＰＢ的ＣＩ几乎相等（ｒ＝０．８９）。ＣｓＣｌ诱发低膜电位水平的ＥＡＤ的ＣＩ较短，其振幅和ＣＩ不随ＣＬ的改变而发生变化，此种ＥＡＤ及ＴＡ可导致短ＣＩ的插入性ＶＰＢ。ＣｓＣｌ还可增加心壁中的不同区域之间的复极离散化趋势，其原因是由于动作电位时程的差异的增加。结论：为ＣｓＣｌ导致的室性心动过速系由于心动过缓依赖性的ＥＡＤ及ＴＡ所致的学说提供了直接证据。明显的动作电位时程的差异可能在心动过速的维持过程中发挥作用。
Objective and Methods: In this study, we used floating glass microelectrode to record the transmembrane action potential (TAP) of cardiomyocytes in order to study the effects of CsCl-induced early post-depolarization (EAD) and triggered electrical activity (TA) As well as the degree of repolarization discretization. Results: The CI (CI) of EAD induced by CsCl at a high level of membrane potential was longer and its amplitude and CI increased with the increase of the stimulation period (CL). These EAD and TA could lead to premature ventricular contractions (VPB) and more The tachycardia, CI of CI and VPB of EAD were nearly equal (r = 0.89). CsCl-induced low membrane potential level of EAD CI is shorter, its amplitude and CI does not change with the change of CL, such EAD and TA can lead to short CI insertion VPB. CsCl may also increase the tendency of repolarization discrepancy between different regions of the heart wall due to the increase of the difference of the action potential duration. Conclusions: The direct evidence that CsCl-induced ventricular tachycardia is due to doctrine of bradycardia-dependent EAD and TA. Significant difference in action potential duration may play a role in the maintenance of tachycardia.