FLUCTUATIONS IN INTERBEAT INTERVAL IN RHYTHMIC HEART-CELL CLUSTERS - ROLE OF MEMBRANE VOLTAGE NOISE
FLUCTUATIONS IN INTERBEAT INTERVAL IN RHYTHMIC HEART-CELL CLUSTERS - ROLE OF MEMBRANE VOLTAGE NOISE
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DOI：
10.1016/s0006-3495(79)85187-5
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发表时间：
1979-01-01
影响因子：
3.4
通讯作者：
DEHAAN, RL
中科院分区：
文献类型：
--
作者：
CLAY, JR;DEHAAN, RL
Small clusters of ventricular cells prepared from 7 day chick heart maintain spontaneous, stationary, rhythmic beating in culture for many hours. For clusters containing 1-125 cells, mean interbeat interval .**GRAPHIC**. is 0.45 .+-. 0.08 s and is independent of cell number (N), whereas the coefficient of variation of IBI (C) is proportional to N-1/2. Because membrane voltage noise in such clusters would also be expected to vary as N-1/2, a model relating fluctuation in IBI (.sigma.IBI) to voltage noise (.sigma.v) is proposed. A simplified model consisting of random voltage fluctuations superimposed upon a linear pacemaker depolarization of slope a is used to analyze the N-dependent shape of the IBI histogram. Vales of .sigma.v derived from the relation .sigma.IBI = .sigma.v/a, or calculated from the skewness of the measured IBI histograms, both agree well with those extrapolated from steady-state noise recorded from resting heart-cell aggregates.
