title: Change of short-term memory effect in acute ischemic ventricular myocardium: a computational study.
abstract: The ionic mechanism of change in short-term memory (STM) during acute myocardial ischemia has not been well understood. In this paper, an advanced guinea pig ventricular model developed by Luo and Rudy was used to investigate STM property of ischemic ventricular myocardium. STM response was calculated by testing the time to reach steady-state action potential duration (APD) after an abrupt shortening of basic cycling length (BCL) in the pacing protocol. Electrical restitution curves (RCs), which can simultaneously visualize multiple aspects of APD restitution and STM, were obtained from dynamic and local S1S2 restitution portrait (RP), which consist of a longer interval stimulus (S1) and a shorter interval stimulus (S2). The angle between dynamic RC and local S1S2 RC reflects the amount of STM. Our results indicated that compared with control (normal) condition, time constant of STM response in the ischemic condition decreased significantly. Meanwhile the angle which reflects STM amount is less in ischemic model than that in control model. By tracking the effect of ischemia on intracellular ion concentration and membrane currents, we declared that changes in membrane currents caused by ischemia exert subtle influences on STM; it is only the decline of intracellular calcium concentration that give rise to the most decrement of STM.
authors: Key Laboratory of Biomedical Information Engineering of Education Ministry, Institute of Biomedical Analytical Technology and Instrumentation, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China; School of Biomedical Engineering, Capital Medical University, Beijing 100069, China.
authors: Xi
authors: X
authors: Mei
authors: Key Laboratory of Biomedical Information Engineering of Education Ministry, Institute of Biomedical Analytical Technology and Instrumentation, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China.
authors: Jing
authors: J
authors: Wang
authors: Key Laboratory of Biomedical Information Engineering of Education Ministry, Institute of Biomedical Analytical Technology and Instrumentation, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China; State Key Laboratory of Power Equipment and Electrical Insulation, School of Electrical Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
authors: Hong
authors: H
authors: Zhang
authors: School of Biomedical Engineering, Capital Medical University, Beijing 100069, China. Electronic address: zcliu@ccmu.edu.cn.
authors: Zhi-cheng
authors: ZC
authors: Liu
authors: Key Laboratory of Biomedical Information Engineering of Education Ministry, Institute of Biomedical Analytical Technology and Instrumentation, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China. Electronic address: zxzhang@mail.xjtu.edu.cn.
authors: Zhen-xi
authors: ZX
authors: Zhang
mesh_terms: D000200:Action Potentials; D000818:Animals; D004195:Disease Models, Animal; D006168:Guinea Pigs; D006352:Heart Ventricles / Q000503:physiopathology*; D007473:Ion Channels / Q000502:physiology; D008955:Models, Cardiovascular; D017202:Myocardial Ischemia / Q000503:physiopathology*; D009994:Osmolar Concentration
chemical_list: D007473:Ion Channels
keywords: Computer modeling; Ionic mechanism; Myocardial ischemia; Short-term memory