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

本研究应用计算机模拟技术分析心律失常发生时心电兴奋波的传播及其相关现象，并研制了一套测量心肌细胞膜动作电位的系统。然后，为了将实验产生的螺旋再入观测结果与仿真结果进行对比，进行了以下研究。(1)心肌动作电位模型模拟及心电兴奋传播可视化：本研究采用LR（Luo-Rudy）模型，用微分方程表示一个心肌单元，用超级计算机模拟心律失常。其次，我们基于螺旋波理论再现了心脏兴奋的传播过程，并成功地实现了传播过程的可视化。c心肌动作电位光学成像系统的研制和全心对电刺激反应的研究采用电压敏感染料di-4-ANEPPS对日本大白兔心脏进行染色，研制了一套高分辨率光学成像系统，用于观察大范围膜动作电位。通过对光信号的分析，可以详细地研究整个心脏对电刺激的响应。(3)以灌注兔心脏为材料，分析螺旋再入动力学与动作电位的关系，探讨抗心律失常药物的作用：利用光学作图系统，从激发旋转动力学、动作电位波形变化和抗心律失常药物的作用等角度，研究灌注兔心脏二维标本的螺旋再入。结果表明，螺旋再入动力学与激振波前与波尾的相互作用、心肌结构的各向异性等有关。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