Heikhmakhtiar Aulia Khamas, Tekle Abrha Abebe, Lim Ki Moo
School of Computing, Telkom University, Bandung, Indonesia.
Research Center of Human Centric Engineering, Telkom University, Bandung, Indonesia.
Front Physiol. 2021 Jun 3;12:644473. doi: 10.3389/fphys.2021.644473. eCollection 2021.
Myocardial fibrosis is an integral component of most forms of heart failure. Clinical and computational studies have reported that spatial fibrosis pattern and fibrosis amount play a significant role in ventricular arrhythmogenicity. This study investigated the effect of the spatial distribution of fibrosis and fibrosis amount on the electrophysiology and mechanical performance of the human ventricles. Seventy-five fibrosis distributions comprising diffuse, patchy, and compact fibrosis types that contain 10-50% fibrosis amount were generated. The spatial fibrosis distribution was quantified using the fibrosis entropy (FE) metric. Electrical simulations under reentry conditions induced using the S1-S2 protocol were conducted to investigate the fibrosis arrhythmogenicity. We also performed mechanical simulations to examine the influence of the fibrosis amount and the spatial distribution of fibrosis on the pumping efficacy of the LV. We observed that the mean FE of the compact type is the largest among the three types. The electrical simulation results revealed that the ventricular arrhythmogenicity of diffuse fibrosis depends on the fibrosis amount and marginally on the spatial distribution of fibrosis. Meanwhile, the ventricular arrhythmogenicity of the compact and patchy fibrosis pattern is more reliant on the spatial distribution of fibrosis than on the fibrosis amount. The average number of phase singularities (PSs) in the compact fibrosis pattern was the highest among the three patterns of fibrosis. The diffuse type of fibrosis has the lowest average number of PSs than that in the patchy and compact fibrosis. The reduction in the stroke volume (SV) showed high influence from the electrical instabilities induced by the fibrosis amount and pattern. The compact fibrosis exhibited the lowest SV among the three patterns except in the 40% fibrosis amount. In conclusion, the fibrosis pattern is as crucial as the fibrosis amount for sustaining and aggravating ventricular arrhythmogenesis.
心肌纤维化是大多数心力衰竭形式的一个重要组成部分。临床和计算研究报告称，空间纤维化模式和纤维化量在心室致心律失常性中起着重要作用。本研究调查了纤维化的空间分布和纤维化量对人体心室电生理和力学性能的影响。生成了75种纤维化分布，包括弥漫性、斑片状和致密性纤维化类型，纤维化量为10%-50%。使用纤维化熵（FE）指标对空间纤维化分布进行量化。采用S1-S2方案在折返条件下进行电模拟，以研究纤维化的致心律失常性。我们还进行了力学模拟，以检查纤维化量和纤维化的空间分布对左心室泵血效率的影响。我们观察到，致密型的平均FE在三种类型中最大。电模拟结果表明，弥漫性纤维化的心室致心律失常性取决于纤维化量，而在一定程度上取决于纤维化的空间分布。同时，致密性和斑片状纤维化模式的心室致心律失常性更依赖于纤维化的空间分布，而不是纤维化量。在三种纤维化模式中，致密性纤维化模式的平均相奇点（PSs）数量最高。弥漫性纤维化类型的平均PSs数量低于斑片状和致密性纤维化。每搏输出量（SV）的降低显示出受纤维化量和模式引起的电不稳定性的高度影响。除纤维化量为40%外，致密性纤维化在三种模式中表现出最低的SV。总之，纤维化模式与纤维化量在维持和加重心室心律失常发生方面同样重要。
