ELECTROPHYSIOLOGIC PROPERTIES OF ISOLATED PREPARATIONS OF HUMAN ATRIAL MYOCARDIUM
ELECTROPHYSIOLOGIC PROPERTIES OF ISOLATED PREPARATIONS OF HUMAN ATRIAL MYOCARDIUM
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DOI：
10.1161/01.res.30.3.293
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发表时间：
1972-01-01
影响因子：
20.1
通讯作者：
HOFFMAN, BF
中科院分区：
文献类型：
--
作者：
GELBAND, H;BUSH, HL;HOFFMAN, BF
本文应用细胞内微电极技术对22例心脏直视手术后右心房组织标本进行了心房电生理特性的研究。两种类型的纤维被确定：第一个具有典型的心房收缩细胞的电特性，第二个心房专门的纤维。自动性只在后一种类型的细胞中发展。在36根特化心房纤维中，静息膜电位为-86 ± 5 mv（mean ±SD），跨膜动作电位振幅为102 ± 12 mv，跨膜动作电位超调为16 ± 4 mv。在49个收缩性纤维穿刺中获得了类似的结果。收缩性纤维的传导速度为0.28-0.33 m/sec，特化心房纤维的传导速度为0.41-0.45 m/sec。动作电位时程的专门心房纤维之间的200和1000毫秒的基本周期长度呈线性关系。在周期长度大于1000毫秒的动作电位时程的增加不再是线性的。当细胞外[K+]增加10倍时，特化心房纤维的静息膜电位降低58 mV。这种下降发生在一个线性的方式[K+]高于5 mM。这些实验提供了参考价值，为今后的研究处理与人类心房组织的电生理。
The electrophysiologic properties of human atrium were studied with intracellular microelectrodes in 22 preparations of human right atrial tissue obtained at the time of corrective open heart surgery. Two types of fibers were identified: the first had electrical characteristics typical of atrial contractile cells and the second those of atrial specialized fibers. Automaticity developed only in the latter type of cell. In 36 impalements of specialized atrial fibers, resting membrane potential was -86 ± 5 mv (mean ±SD), transmembrane action potential amplitude was 102 ± 12 mv, transmembrane action potential overshoot was 16 ± 4 mv. Similar results were obtained in 49 impalements of contractile fibers. Conduction velocity measured 0.28-0.33 m/sec in contractile fibers and 0.41-0.45 m/sec in specialized atrial fibers. Action potential duration of specialized atrial fibers was linearly related to the basic cycle length between 200 and 1000 msec. At cycle lengths greater than 1000 msec the increase in action potential duration was no longer linear. There was a decrease of 58 mv in resting membrane potential of specialized atrial fibers when exposed to a tenfold increase in extracellular [K+]. This decrease occurred in a linear fashion in [K+] above 5 mM. These experiments provide reference values for future studies dealing with electrophysiology of human atrial tissue.