基于精细解剖结构的左心室心肌缺血仿真

Simulation of left ventricular ischemia based on anatomically detailed geometry

为解释心肌缺血诱发心律失常的机理,基于精细的人体心脏解剖数据,构建了一个整合的人体心室组织模型,并模拟了心肌缺血对折返波的影响.在处理无通量边界问题上,采用相场法来自动处理复杂的边界条件.通过增加缺血区域内细胞外钾离子浓度值,模拟了心肌缺血环境下折返波的传播过程.实验结果表明,折返波会随着缺血程度的改变而变化.随着缺血程度的增加,折返波越来越不稳定,甚至会发生断裂现象.缺血组织的心肌细胞动作电位也将发生改变,导致动作电位的空间不一致性.

Based on the anatomically detailed geometry of human heart, an integrated human ventricle model is proposed to simulate the reentrant wave propagation for studying the generation mechanism of arrhythmia caused by myocardial isehemia. To deal with the no-flux boundary conditions, the phase-field method is adopted to automatically handle the complicated boundary conditions. Through increasing the concentration of extracellular K^＋ in the ischemic region, reentrant spiral wave dynamics under different ischemic conditions is simulated. Experimental results show that the degree of myocardial isehemia would have an important influence on the behavior of wave propagation. With the increasing of myocardial ischemia, the reentrant wave would become more and more instable, which eventually leads to breakup. Although the reentrant wave can pass through the ischemic region, the behavior of action potentials of myocardial cells in the ischemic region would be different from the normal behavior, and the inconsistency of action potentials in space is the intrinsic reason for the emergence of arrhythmia.