Mechanisms for discordant alternans
Mechanisms for discordant alternans
复制标题
DOI：
10.1046/j.1540-8167.2001.00196.x
复制
发表时间：
2001-02-01
影响因子：
2.7
通讯作者：
Karma, A
中科院分区：
文献类型：
--
作者：
Watanabe, MA;Fenton, FH;Karma, A
不一致的替代机制。简介：不一致的交替有可能比一致的交替产生更大的心电图 T 波交替，但其机制尚不清楚。方法和结果：我们通过动作电位传播模型的一维和二维模拟证明，由于高起搏频率下传导速度和动作电位持续时间恢复的相互作用或通过异位产生的舒张间隔的分散，不一致的交替可以通过两种机制之一在空间均匀的组织中自发形成。焦点。在由于第一种机制导致的不一致的交替中，具有相反相位的交替的边界标记区域远离刺激位点，向刺激位点移动并稳定。由于电紧张耦合导致的动作电位持续时间恢复曲线的动态分裂在这种稳定性中起着至关重要的作用。较大的组织和较快的起搏速率有利于多个边界，并且组织特性的不均匀性促进或抑制边界的形成。结论：电恢复特性的空间不均匀性不需要产生不一致的交替。
Discordant Altelrnans Mechanism. Introduction: Discordant alternans has the potential to produce larger alternans of the ECG T wave than concordant alternans, but its mechanism is unknown.Methods and Results: We demonstrate by one- and two-dimensional simulation of action potential propagation models that discordant alternans can form spontaneously in spatially homogeneous tissue through one of two mechanisms, due to the interaction of conduction velocity and action potential duration restitution at high pacing frequencies or through the dispersion of diastolic interval produced by ectopic foci. In discordant alternans due to the first mechanism, the boundaries marking regions of alternans with opposite phase arise far from the stimulus site, move toward the stimulus site, and stabilize. Dynamic splitting of action potential duration restitution curves due to electrotonic coupling plays a crucial role in this stability. Larger tissues and faster pacing rates are conducive to multiple boundaries, and inhomogeneities of tissue properties facilitate or inhibit formation of boundaries.Conclusion: Spatial inhomogeneities of electrical restitution properties are not required to produce discordant alternans.