Liang Cuiping, Wang Kuanquan, Li Qince, Zhang Henggui
Annu Int Conf IEEE Eng Med Biol Soc. 2019 Jul;2019:305-308. doi: 10.1109/EMBC.2019.8856915.
Sudden cardiac death (SCD) is mainly induced by ventricular arrhythmia, especially among patients with myocardial infarction (MI). Previous studies have shown that ventricular tachycardia and fibrillation are thought to be caused by re-entrant waves of excitation. Although in heterogeneous tissue, the traditional vulnerable window of unidirectional block and the vulnerable window when bidirectional propagation was initiated could coexist, little studies are based on effects of infarcted areas on both vulnerable windows.
The electrophysiology remodeling was based on TP06 model in the present study. In simulation of two-dimension (2D) ideal models, excitation wave conduction in ventricular tissue was simulated under three different types of stimulus. 2D ideal models of ventricular tissue were constructed as loop areas in the center of a square tissue with the resolution of 600×600 grid points and cell size of 0.35mm. Simulation results showed that the traditional vulnerable window when unidirectional propagation was initiated was consistent no matter where the position of stimulus is and how long and how wide the size of the infarcted area is. However, the vulnerable window when bidirectional propagation was initiated varies in different conditions.
The traditional vulnerable window could not reflect the role of the infarcted area on arrhythmogenesis. The vulnerable window when bidirectional propagation was initiated increases with the increasement of the width and the length of the infarcted area with the appropriate position of the stimulus, which could help us to conclude the arrhythmogenesis according to the size of infarcted areas.
心脏性猝死（SCD）主要由室性心律失常诱发，尤其是在心肌梗死（MI）患者中。既往研究表明，室性心动过速和颤动被认为是由折返性兴奋波引起的。尽管在异质性组织中，传统的单向阻滞易损窗口和双向传播开始时的易损窗口可能共存，但基于梗死区域对这两个易损窗口影响的研究较少。
本研究基于TP06模型进行电生理重塑。在二维（2D）理想模型模拟中，在三种不同类型的刺激下模拟心室组织中的兴奋波传导。将心室组织的二维理想模型构建为正方形组织中心的环形区域，分辨率为600×600个网格点，细胞大小为0.35mm。模拟结果表明，无论刺激位置如何以及梗死区域的大小和长宽如何，单向传播开始时的传统易损窗口都是一致的。然而，双向传播开始时的易损窗口在不同条件下有所不同。
传统易损窗口无法反映梗死区域在心律失常发生中的作用。在刺激位置合适的情况下，双向传播开始时的易损窗口随着梗死区域宽度和长度的增加而增大，这有助于我们根据梗死区域大小推断心律失常的发生机制。
