心肌透壁缺血时心脏表面心电图ST段位移的仿真研究

A COMPUTER SIMULATION OF EPICARDIAL ST SEGMENT SHIFT INMYOCARDIAL TRANSMURAL ISCHAEMIA

利用心肌的双域模型计算机模拟了不同区域心肌透壁缺血时ＳＴ 段位移在心脏表面的分布，发现心脏表面ＳＴ 段位移的分布式样和缺血区域大小有关，一个小面积的透壁缺血在缺血区上出现均匀分布的ＳＴ 段上升， 而在心脏表面的其他部位上几乎没有出现ＳＴ 段下降； 一个大面积的缺血像左降支或左旋支区域的缺血， ＳＴ 段位移在心脏表面的左侧区出现了一个偶极子式的分布，在缺血区为ＳＴ 段上升， 在正常区为ＳＴ 段下降， 并且其幅度随远离缺血边界而减小； 同时发现透壁缺血时的ＳＴ 段下降是缺血电流源的不可分割的一部分。 比较了这些模拟结果和在动物实验中所观察到的ＳＴ 段位移的变化，从而分析了本文得到的结论在临床上定位心肌缺血的指导意义。

The paper describes a computer simulation of epicardial ST segment shift in myocardial transmural ischaemia. Epicardial ST distribution was found to be related with the size of ischaemic region. Ischaemia of a small region produced localised ST elevation over ischaemic region with little ST depression elsewhere on the epicardium. Ischaemia of a large region such as that in either the LAD or LCX territory produced a strong dipole of ST changes on the epicardium over the left lateral region, with ST elevation on the ischaemic region and ST depression on the nonischaemic region. ST depression in transmural ischaemia was generated with ST elevation and was an integral part of the current source. These simulation results correlated well with animal experimental results. Therefore the bidomain model is successful in modelling the ST potentials. It provides useful guidance for localising ischaemia using ST segment shift in clinic.