RELATING EXTRACELLULAR POTENTIALS AND THEIR DERIVATIVES TO ANISOTROPIC PROPAGATION AT A MICROSCOPIC LEVEL IN HUMAN CARDIAC-MUSCLE - EVIDENCE FOR ELECTRICAL UNCOUPLING OF SIDE-TO-SIDE FIBER-CONNECTIONS WITH INCREASING AGE
RELATING EXTRACELLULAR POTENTIALS AND THEIR DERIVATIVES TO ANISOTROPIC PROPAGATION AT A MICROSCOPIC LEVEL IN HUMAN CARDIAC-MUSCLE - EVIDENCE FOR ELECTRICAL UNCOUPLING OF SIDE-TO-SIDE FIBER-CONNECTIONS WITH INCREASING AGE
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DOI：
10.1161/01.res.58.3.356
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发表时间：
1986-03-01
影响因子：
20.1
通讯作者：
DOLBER, PC
中科院分区：
文献类型：
--
作者：
SPACH, MS;DOLBER, PC
阐明导致折返的心脏传导紊乱的机制将需要在微观尺寸尺度（< 200 μ m）上解析多维传播的细节。在实践中，这需要对细胞外和跨膜动作电位进行综合分析。本文的目的是证明细胞外波形的时间导数和潜在的动作电位之间的关系，在这个小尺寸尺度上的各向异性传播的实验分析，并将这些关系应用于不同年龄的人心房肌。细胞外波形及其衍生物的变化从一个光滑的轮廓在横向传播的年轻的准备复杂的多相波形在较老的准备。主要的问题是估计在旧的制备中产生复杂波形的小纤维群的大小和位置。我们发现的衍生工具，区分源（束）的大小从源的距离测量站点的差异。细胞外波形及其衍生物的差异表明，随着年龄的增长，小群体纤维之间的侧到侧连接存在电解偶联。这些变化产生了一个突出的曲折过程中的横向传播在微观水平，这反过来又占了波形的复杂性增加。波形的差异也与广泛的胶原间隔的发展，分离小的纤维群。与年龄相关的“有效"横向传导速度降低到非常慢的传导范围（< 0.08 m/sec）的电生理后果，这使得折返可能发生在具有正常细胞电生理特性的心肌小区域。
Elucidation of the mechanisms of cardiac conduction disturbances leading to reentry will require resolution of the details of multidimensional propagation at a microscopic size scale (< 200 .mu.m). In practice, this will necessitate the combined analysis of extracellular and transmembrane action potentials. The purpose of this paper is to demonstrate the relationships between the time derivatives of the extracellular waveforms and the underlying action potentials in the experimental analysis of anisotropic propagation at this small size scale, and apply these relationships to human atrial muscle at different ages. The extracellular waveforms and their derivatives changed from a smooth contour during transverse propagation in young preparations to complex polyphasic waveforms in the older preparations. The major problem was to estimate the size and location of small groups of fibers that generated the complex waveforms in the older preparations. We found dissimilarities in the derivatives that distinguished source (bundle) size from the distance of the source to the measurement site. The differences in the extracellular waveforms and their derivatives indicated that there was electrical uncoupling of the side-to-side connections between small groups of fibers with aging. These changes produced a prominent zigzag course of transverse propagation at a microscopic level which, in turn, accounted for the increased complexity of the waveforms. The waveform differences also correlated with the development of extensive collagenous septa that separated small groups of fibers. The electrophysiological consequence with an age-related decrease in the ''effective'' transverse conduction velocities to the range of the very slow conduction (< 0.08 m/sec) which makes it possible for reentry to occur in small regions of cardiac muscle with normal cellular electrophysiological properties.