An integrative appraisal of mechano-electric feedback mechanisms in the heart.
An integrative appraisal of mechano-electric feedback mechanisms in the heart.
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DOI：
10.1016/j.pbiomolbio.2017.08.008
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发表时间：
2017-11
影响因子：
3.8
通讯作者：
Wall ST
中科院分区：
文献类型：
--
作者：
Timmermann V;Dejgaard LA;Haugaa KH;Edwards AG;Sundnes J;McCulloch AD;Wall ST
机械诱导的心脏电生理学改变被称为机械电反馈（MEF），并在心脏性能的电调节中发挥重要作用。机械应力和应变对电生理的影响已在各个层面进行了研究，但MEF在心律失常中的作用仍然知之甚少。在心脏的正常收缩期间，机械敏感过程是心脏活动的隐含组成部分。在异常的机械事件下，牵张激活机制可能导致电生理（EP）的局部或全局变化。虽然这些机制已被假设为参与机械引发的心律失常，这些机制的细节和它们的重要性仍然难以捉摸。我们使用细胞电生理学和肌节收缩动力学的耦合模型来评估拉伸机制的理论作用。使用单个心室肌细胞模型，我们首先研究了牵张激活电流（SAC）和牵张诱导的肌丝钙释放的潜在MEF贡献，以测试应变和纤维化如何改变细胞电生理学。对于研究的所有模型，单独的SAC不足以对牵张动作电位产生致心律失常的扰动。然而，当结合牵张诱导的肌丝钙释放时，动作电位可以缩短，这取决于应变的时间。该效应高度依赖于模型，犬心外膜EP模型最敏感。这些模型的结果表明，已知的机制的机械-电耦合在心肌细胞可能是足够的pro-mammic，但只有在组合和特定的应变模式。
Mechanically-induced alterations in cardiac electrophysiology are referred to as mechano-electric feedback (MEF), and play an important role in electrical regulation of cardiac performance. The influence of mechanical stress and strain on electrophysiology has been investigated at all levels, however the role of MEF in arrhythmia remains poorly understood. During the normal contraction of the heart, mechano-sensitive processes are an implicit component of cardiac activity. Under abnormal mechanical events, stretch-activated mechanisms may contribute to local or global changes in electrophysiology (EP). While such mechanisms have been hypothesised to be involved in mechanically-initiated arrhythmias, the details of these mechanisms and their importance remain elusive. We assess the theoretical role of stretch mechanisms using coupled models of cellular electrophysiology and sarcomere contraction dynamics. Using models of single ventricular myocytes, we first investigated the potential MEF contributions of stretch-activated currents (SAC), and stretch-induced myofilament calcium release, to test how strain and fibrosis may alter cellular electrophysiology. For all models investigated, SACs were alone not sufficient to create a pro-arrhythmic perturbation of the action potential with stretch. However, when combined with stretch-induced myofilament calcium release, the action potential could be shortened depending on the timing of the strain. This effect was highly model dependent, with a canine epicardial EP model being the most sensitive. These model results suggest that known mechanisms of mechano-electric coupling in cardiac myocyte may be sufficient to be pro-arrhythmic, but only in combination and under specific strain patterns.
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影响因子：
3.4
作者：
Maleckar, Mary M.;Greenstein, Joseph L.;Trayanova, Natalia A.
通讯作者：
Trayanova, Natalia A.
影响因子：
2.7
作者：
Kohl, P;Bollensdorff, C;Garny, A
通讯作者：
Garny, A
影响因子：
3.8
作者：
Chase, PB;Macpherson, JM;Daniel, TL
通讯作者：
Daniel, TL
DOI：
10.1002/cnm.2570
发表时间：
2013-12-01
影响因子：
2.1
作者：
de Oliveira, B. L.;Rocha, B. M.;Weber dos Santos, R.
通讯作者：
Weber dos Santos, R.
影响因子：
6.1
作者：
Healy, SN;McCulloch, AD
通讯作者：
McCulloch, AD