Space Dynamics and Data Analysis Department, Space Research Institute, Russian Academy of Sciences, Moscow 117997, Russia.
Prog Biophys Mol Biol. 2010 Sep;103(1):131-41. doi: 10.1016/j.pbiomolbio.2010.01.004. Epub 2010 Feb 11.
The underlying mechanisms of irregular cardiac rhythms are still poorly understood. Many experimental and modeling studies are aimed at identifying factors which cause cardiac arrhythmias. However, a lack of understanding of heart rhythm dynamical properties makes it difficult to uncover precise mechanisms of electrical instabilities, and hence to predict the onset of heart rhythm disorders. We review and compare the existing methods of studying cardiac dynamics, including restitution protocol (S1-S2), dynamic restitution protocol and multistability test protocol (S1-CI-S2). We focus on cardiac cell dynamics to elucidate regularities of heart rhythm. We demonstrate the advantages of our newly proposed systematic approach of analysis of cardiac cell dynamics using mammalian Luo Rudy 1991 and human ventricular Ten Tusscher 2006 single cell models under healthy and diseased conditions such as altered K(+) or Ca(2+) related currents. We investigate the role of ionic properties and the shape of an action potential on the nonlinear dynamics of electrical processes in periodically stimulated cardiac cells. We show the existence of multistability property for human ventricular cells. Moreover, the multistability is proposed to be an intrinsic property of cardiac cells, and is also suggested to be one of the mechanisms which could underlie the sudden triggering of life-threatening ventricular arrhythmias in the human heart.
心律失常的潜在机制仍未被充分理解。许多实验和建模研究旨在确定引起心律失常的因素。然而，由于对心脏节律动力学特性缺乏了解，很难揭示电不稳定性的确切机制，从而难以预测心律失常的发作。我们回顾并比较了现有的心脏动力学研究方法，包括恢复协议（S1-S2）、动态恢复协议和多稳定性测试协议（S1-CI-S2）。我们专注于心脏细胞动力学，以阐明心脏节律的规律。我们展示了使用哺乳动物 Luo Rudy 1991 和人类心室 Ten Tusscher 2006 单细胞模型在健康和疾病条件下（如改变的 K(+)或 Ca(2+)相关电流）分析心脏细胞动力学的新提出的系统方法的优势。我们研究了离子特性和动作电位形状对周期性刺激心脏细胞中电过程的非线性动力学的作用。我们展示了人类心室细胞存在多稳定性特性。此外，多稳定性被认为是心脏细胞的固有特性之一，也被认为是导致人类心脏危及生命的室性心律失常突然触发的机制之一。
