Lou Qing, Efimov Igor R
Washington University, St. Louis, MO 63130 USA.
Annu Int Conf IEEE Eng Med Biol Soc. 2009;2009:4527-30. doi: 10.1109/IEMBS.2009.5334102.
The aim of this study is to examine how structural discontinuity and functional remodeling changes the susceptibility to alternans of action potential duration (APD) in a rabbit model of chronic myocardial infarction (MI). Optical mapping experiments using voltage-sensitive dyes were performed in 14 rabbit hearts. We found that (1) APD alternans starts at a significantly slower pacing rate in hearts with MI (n = 7) than in normal hearts (n = 7), with the original sites of alternans of APD located in the infarct region and infarct adjacent regions. (2) Alternans of activation cycle length (CL) precedes the occurrence of spatially discordant alternans of APD, with the regions of activation CL alternans located in the infarct adjacent regions. Based on these results, we conclude that susceptibility to alternans are significantly enhanced in this rabbit model of chronic MI, and the enhancement is strongly correlated to structural and functional heterogeneity imposed by the infarction.
本研究的目的是在慢性心肌梗死（MI）兔模型中，研究结构不连续和功能重塑如何改变动作电位时程（APD）对交替性变化的易感性。使用电压敏感染料对14只兔心脏进行了光学标测实验。我们发现：（1）与正常心脏（n = 7）相比，MI心脏（n = 7）中APD交替性变化起始时的起搏频率明显更低，APD交替性变化的原始部位位于梗死区域和梗死相邻区域。（2）激活周期长度（CL）的交替性变化先于APD的空间不一致性交替性变化出现，激活CL交替性变化的区域位于梗死相邻区域。基于这些结果，我们得出结论，在该慢性MI兔模型中，对交替性变化的易感性显著增强，且这种增强与梗死引起的结构和功能异质性密切相关。
