Analysis and imaging of arrhythmia electrophysiological phenomena in the heart by modeling and experimental investigation of them

本研究将计算机模拟技术应用于分析心律失常发生时心脏兴奋波的传播及相关现象，研制了一套心肌细胞膜动作电位测量系统。然后，进行了以下研究，以比较实验产生的螺旋再入观测结果和模拟结果。(1)心肌动作电位模型的模拟和心脏兴奋传播的可视化：本研究采用LR(Luo-Rudy)模型将一个心肌单位用微分方程式表示，并用超级计算机进行心律失常的模拟。其次，我们基于螺旋波理论再现了心脏兴奋的传播过程，并成功地对其传播进行了可视化。c.研制了心肌动作电位光学标测系统，并研究了整个心脏对电…的反应通过对光信号的分析获得更多的刺激：我们研制了一套高分辨率的光学标测系统，用两台高速摄像机对用电压敏感染料di-4-ANEPPS染色的日本大白兔心脏的膜动作电位进行了广泛的观察。利用该系统对光信号进行分析，可以详细地研究整个心脏对电刺激的响应。(3)以兔心脏灌流为材料，分析螺旋折返动力学与动作电位的关系及抗心律失常药物作用的研究：利用光学标测系统，从兴奋旋转动力学、动作电位波形变化及抗心律失常药物作用的角度，对二维标本的螺旋折返进行了研究。结果表明，螺旋折返的动力学特性与波头和激励尾部的相互作用、心肌结构的各向异性等因素有关。较少

In the present study we applied techniques of computer simulation to analyzing propagation of cardiac excitation wave at the occurrence of arrhythmia and its related phenomena and developed a system for measuring action potential of myocardial cell membrane. Then, the following investigations were conducted in order to compare observation results of spiral reentry generated by experiments with results of the simulation. (1) Simulation by using a model of myocardial action potential and visualization of propagation of cardiac excitation : In this study, one myocardial unit was expressed by the differential equation by using LR(Luo-Rudy) model and the simulation of arrhythmias was performed with a supercomputer. Secondly, we reproduced the propagation of cardiac excitation based on the theory of spiral wave and succeeded in visualization of the propagation.c Development of a optical mapping system of myocardial action potential and investigation of responses of a whole heart to electric … More stimuli by analyzes of optical signals : We developed a high-resolution optical mapping system with two high-speed video digital cameras to observe widely membrane action potential of a heart of a Japanese white rabbit which was dyed using the voltage sensitive dye di-4-ANEPPS. The responses of the whole heart to the electric stimuh can be investigated in detail by the analyzes of optical signals with the system. (3) Analysis of the relationship between dynamics of spiral reentry and the action potential using the perfused rabbit heart as materials and investigation of function of anti-arrhythmic drugs : By using the optical mapping system, the spiral reentry of two-dimensional specimen of the perfused rabbit heart is investigated from the viewpoint of dynamics of excitation rotation and changes in the wave shape of action potential and the function of anti-arrhythmic drugs. As the results, it was revealed that the dynamics of the spiral reentry was associated with interaction of the wave fronts and the tails of excitation, anisotropy of myocardial structure and so on. Less