The electrical restitution curve revisited: Steep or flat slope - Which is better?
The electrical restitution curve revisited: Steep or flat slope - Which is better?
复制标题
DOI：
10.1046/j.1540.8167.90303.x
复制
发表时间：
2003-10-01
影响因子：
2.7
通讯作者：
Franz, MR
中科院分区：
文献类型：
--
作者：
Franz, MR
电气维修电恢复曲线（ERC）传统上描述了动作电位时程（APD）的恢复作为心搏间期或更准确地说是舒张间期的函数（131）。在建模研究中经常被忽视，正常心室ERC是三相的，在最短DI时开始陡峭的初始恢复，短暂下降，最后逐渐上升到长DI时达到的平台期。最近的研究提出，通过药物干预降低ERC的斜率是有利的，因为这可能会降低电交替和室颤的可能性。本综述讨论了ERC的平坦与陡峭斜率的利弊，并提请注意证明（生理）陡峭斜率而不是平坦斜率是对抗心律失常的更好设计的机制。五个潜在的机制进行了讨论，这使得一个不同的解释的影响的斜率对mammogenicity。最重要的似乎是APD的生理率适应性缩短，通过DI的相互延长，允许随后的APD更快地从陡峭的初始ERC阶段移动到平坦阶段。不太陡的初始ERC相位将延长向更完全恢复的APD的过渡，并且事实上，可能使电交替永久化。正常心肌的三相ERC时间过程不能用单指数或单离子通道恢复动力学来解释或拟合。一个简单的三离子模型的建议，可能有助于解释ERC的形状在不同的复极水平，并将APD恢复的角度与细胞内钙循环和收缩力的恢复。
Electrical Restitution. The electrical restitution curve (ERC) traditionally describes the recovery of action potential duration (APD) as a function of the interbeat interval or, more correctly, the diastolic interval (131). Often overlooked in modeling studies, the normal ventricular ERC is triphasic, starting with a steep initial recovery at the shortest DIs, a transient decline, and a final asymptotic rise to a plateau phase reached at long DIs. Recent studies have proposed that it would be advantageous to lower the slope of the ERC by drug intervention, as this might reduce the potential for electrical alternans and ventricular fibrillation. This review discusses the pros and cons of a flat versus steep slope of the ERC and draws attention to mechanisms that justify the (physiologically) steep slope, rather than a flat slope, as a better design against arrhythmias. Five potential mechanisms are discussed, which allows for a different interpretation of the effect of the slope on arrhythmogenicity. The most important appears to be the physiologic rate adaptive shortening of APD that, by reciprocal lengthening of the DI, allows the subsequent APD to move more quickly from the steep initial ERC phase onto the flat phase. A less steep initial ERC phase would protract the transition toward more fully recovered APD and, in fact, may perpetuate electrical alternans. The triphasic ERC time course in normal myocardium cannot be explained by or fitted to single exponentials or single ion channel recovery kinetics. A simple tri-ionic model is suggested that may help explain the shape of the ERC at various repolarization levels and place APD recovery into perspective with intracellular calcium recycling and recovery of contractile force.