钾扩散耦合引起的心脏中螺旋波的变化

Potassium diffusive coupling-induced the variation of spiral wave in cardiac tissues

在某些情况下,心肌细胞外的钾离子浓度是变化的,钾离子的横向扩散会导致细胞外钾离子的聚集和产生钾扩散耦合,用考虑钾扩散耦合的Luo-Rudy相I心脏模型研究了钾扩散耦合对螺旋波动力学的影响.数值模拟结果表明:当钾扩散耦合比较强时,钾扩散耦合使细胞外钾离子浓度先升高,然后做规则振荡,导致螺旋波做无规则漫游;观察到螺旋波的波臂宽度和频率随钾扩散耦合的强度增大而减小,这样,当钾扩散耦合足够强时,钾扩散耦合可以消除螺旋波和时空混沌.

In some cases, the extracellular concentration of potassium ions cannot be regarded as being constant. The potassium lateral diffusion leads to extracellular accumulation of potassium ions and the generation of potassium diffusive coupling. The effect of potassium diffusive coupling on spiral wave is investigated by using the Luo-Rudy phase I cardiac model with potassium diffusive coupling. The numerical results show that when the strength of potassium diffusive coupling is relatively strong, the potassium diffusive coupling makes extracellular potassium ion concentration rise first and then regularly oscillate, leading to the irregular meandering of spiral wave. It is observed that the width of spiral arm and the frequency of spiral wave decrease as the strength of potassium diffusive coupling increases. Thus, when the strength of the potassium diffusive coupling is strong enough, the potassium diffusive coupling can eliminate spiral wave and spatiotemporal chaos.