Activation sequence as a key factor in spatio-temporal optimization of myocardial function.
Activation sequence as a key factor in spatio-temporal optimization of myocardial function.
复制标题
激活序列是心肌功能时空优化的关键因素。
DOI：
10.1098/rsta.2006.1777
复制
发表时间：
2006
期刊：
影响因子：
--
通讯作者：
Markhasin,VS
中科院分区：
文献类型：
--
作者：
Solovyova,O;Katsnelson,LB;Konovalov,P;Lookin,O;Moskvin,AS;Protsenko,YuL;Vikulova,N;Kohl,P;Markhasin,VS
使用心肌组织的一维模型，实现为运动学上串联连接的虚拟心室肌段的链，我们研究了激励序列在心脏功能的时空组织中的作用。每个模型元素都由经过充分验证的心脏机电活动数学模型表示。我们发现，均匀的链，由相同的元素组成，响应于非同时刺激的生成复杂的时空异质性元素变形。这些都伴随着建立显着的梯度在局部机电性能的元素（动作电位持续时间的异质性，Ca2+瞬态特性和肌浆网Ca2+负载）。在异质链，模拟快速和缓慢的收缩心肌细胞从不同的透壁层的元素组成，我们发现，只有激活序列的刺激较慢的元素之前，较快的系统的机电功能，这是实验证实的优化。基于所获得的结果，我们假设，在不同的心室层的心肌细胞的激活顺序是心肌的时空组织的关键因素之一。此外，激活序列和心肌内在电机械特性的区域差异必须匹配，以优化心肌功能。
Using one-dimensional models of myocardial tissue, implemented as chains of virtual ventricular muscle segments that are kinematically connected in series, we studied the role of the excitation sequence in spatio-temporal organization of cardiac function. Each model element was represented by a well-verified mathematical model of cardiac electro-mechanical activity. We found that homogeneous chains, consisting of identical elements, respond to non-simultaneous stimulation by generation of complex spatio-temporal heterogeneities in element deformation. These are accompanied by the establishment of marked gradients in local electro-mechanical properties of the elements (heterogeneity in action potential duration, Ca2+transient characteristics and sarcoplasmic reticulum Ca2+loading). In heterogeneous chains, composed of elements simulating fast and slow contracting cardiomyocytes from different transmural layers, we found that only activation sequences where stimulation of the slower elements preceded that of faster ones gave rise to optimization of the system's electro-mechanical function, which was confirmed experimentally. Based on the results obtained, we hypothesize that the sequence of activation of cardiomyocytes in different ventricular layers is one of the key factors of spatio-temporal organization of myocardium. Moreover, activation sequence and regional differences in intrinsic electro-mechanical properties of cardiac muscle must be matched in order to optimize myocardial function.