Mathematical analysis of dynamics of cardiac memory and accommodation: theory and experiment.
Mathematical analysis of dynamics of cardiac memory and accommodation: theory and experiment.
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DOI：
10.1152/ajpheart.00351.2001
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发表时间：
2002-04
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影响因子：
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通讯作者：
Mari A. Watanabe;M. Koller
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文献类型：
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作者：
Mari A. Watanabe;M. Koller
减小动态恢复曲线的斜率，而不是传统的恢复曲线的斜率是反方向的。心脏记忆/调节是这种差异的基础。我们测量了8只狗的心外膜、心内膜和浦肯野组织的舒张间期（DI）和动作电位时程（APD）。连续100刺激序列，研究基本周期长度（BCL）之间的过渡范围从400到1,300毫秒。（DI，APD）对直接对齐线DI + APD = BCL（64/67）或振荡（3/67）。还测量了多达10个额外刺激对恢复曲线的移位效应。这些曲线用方程APD = alpha + beta exp（-DI/tau）拟合，其中alpha是渐近线，beta是下降，tau是时间常数。对extrastimuli的数量的参数的线性回归表明，过早和过成熟的刺激减少和增加α和β和增加和减少tau，分别。对将记忆视为恢复曲线的指数下降移位的数学模型的分析表明，预期振荡DI、APD具有大的DeltaBCL、陡峭的恢复斜率或增加的心脏调节。该模型解释了相移，并提出了一个共同的机制浦肯野和心肌电交替。
Decreasing the slope of the dynamic, but not conventional, restitution curves is antifibrillatory. Cardiac memory/accommodation underlies the difference. We measured diastolic interval (DI) and action potential duration (APD) in epicardial, endocardial, and Purkinje tissue from eight dogs. Consecutive 100-stimulus trains were given to study transitions between basic cycle lengths (BCL) ranging from 400 to 1,300 ms. (DI,APD) pairs aligned immediately on the line DI + APD = BCL (64/67) or oscillated (3/67). The shifting effect of up to 10 extrastimuli on restitution curves was also measured. These curves were fit with the equation APD = alpha + beta exp(-DI/tau), where alpha is asymptote, beta is drop, and tau is time constant. Linear regression of the parameters against the number of extrastimuli showed that premature and postmature stimuli decreased and increased alpha and beta and increased and decreased tau, respectively. Analysis of a mathematical model treating memory as an exponentially decreasing shift of restitution curves shows that oscillatory DI,APD is expected with large DeltaBCL, steep restitution slope, or increased cardiac accommodation. The model explains phase shifts and suggests a common mechanism for Purkinje and myocardial electrical alternans.