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首页> 外文期刊>American Journal of Physiology >Effects of Na(+) channel and cell coupling abnormalities on vulnerability to reentry: a simulation study.
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Effects of Na(+) channel and cell coupling abnormalities on vulnerability to reentry: a simulation study.

机译：Na（+）通道和细胞偶联异常对再入脆弱性的影响：模拟研究。

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The role of dynamic instabilities in the initiation of reentry in diseased (remodeled) hearts remains poorly explored. Using computer simulations, we studied the effects of altered Na(+) channel and cell coupling properties on the vulnerable window (VW) for reentry in simulated two-dimensional cardiac tissue with and without dynamic instabilities. We related the VW for reentry to effects on conduction velocity, action potential duration (APD), effective refractory period dispersion and restitution, and concordant and discordant APD alternans. We found the following: 1). reduced Na(+) current density and slowed recovery promoted postrepolarization refractoriness and enhanced concordant and discordant APD alternans, which increased the VW for reentry; 2). uniformly reduced cell coupling had little effect on cellular electrophysiological properties and the VW for reentry. However, randomly reduced cell coupling combined with decoupling promoted APD dispersion and alternans, which also increased the VW forreentry; 3). the combination of decreased Na(+) channel conductance, slowed Na(+) channel recovery, and cellular uncoupling synergistically increased the VW for reentry; and 4) the VW for reentry was greater when APD restitution slope was steep than when it was flat. In summary, altered Na(+) channel and cellular coupling properties increase vulnerability to reentrant arrhythmias. In remodeled hearts with altered Na(+) channel properties and cellular uncoupling, dynamic instabilities arising from electrical restitution exert important influences on the VW for reentry.
机译：动态不稳定性在患病（重塑）心脏再入的开始中的作用仍未得到很好的研究。使用计算机模拟，我们研究了改变的Na（+）通道和细胞耦合特性对具有和不具有动态不稳定性的模拟二维心脏组织中折返的脆弱窗口（VW）的影响。我们将可折返的大众汽车与传导速度，动作电位持续时间（APD），有效不应期分散和恢复以及一致和不一致APD交替变化的影响相关。我们发现以下内容：1）。 Na（+）电流密度的降低和恢复速度的降低促进了复极后的耐火度，增强了一致和不一致的APD交替，从而增加了折返的大众。 2）。均匀降低的细胞偶联对细胞电生理特性和再入大众的影响很小。然而，随机减少的细胞偶联结合去偶联促进了APD的分散和交替，这也增加了大众的肠胃蠕动。 3）。 Na（+）通道电导降低，Na（+）通道恢复减慢和细胞解偶联协同增加了再入的大众。 4）APD恢复坡度陡峭时再入的大众比平坦时更大。总之，改变的Na（+）通道和细胞偶联特性增加了折返性心律失常的易感性。在具有改变的Na（+）通道特性和细胞解偶联的重塑心脏中，由电恢复引起的动态不稳定性对VW的折返施加了重要影响。

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