Arterial viscoelasticity: role in the dependency of pulse wave velocity on heart rate in conduit arteries
Arterial viscoelasticity: role in the dependency of pulse wave velocity on heart rate in conduit arteries
复制标题
动脉粘弹性：导管动脉中脉搏波速度对心率的依赖性的作用
DOI：
10.1152/ajpheart.00849.2016
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发表时间：
2017-06-01
影响因子：
4.8
通讯作者：
Avolio, Alberto P.
中科院分区：
文献类型：
--
作者：
Xiao, Hanguang;Tan, Isabella;Avolio, Alberto P.
实验研究表明，大动脉的硬度与急性心率（HR）的变化有关。然而，这种人力资源依赖所固有的潜在机制尚未得到很好的确立。本研究旨在探讨HR对动脉硬度影响的粘弹性机制。采用人体动脉树的多节段传输线模型，在每个节段中加入分数阶粘弹性分量，研究不同分数阶粘弹性参数（alpha）对主动脉弓-股动脉脉波速度（afPWV）对HR的依赖性的影响。心率变化范围为60 ~ 100次/min，平均流速为100 ml/s。在时域和频域分别采用交切法（afPWV(Tan)）和传递函数相速度法（afPWVTF）计算PWV。PWV与HR呈显著正相关，α >= 0.6；当α = 0.6、0.8和1时，心率相关的afPWVTan变化分别为0.01 +/- 0.02、0.07 +/- 0.04和0.22 +/- 0.09 m/s / 5次/min；心率相关的afPWV（TF）变化分别为每5次/分0.02 +/- 0.01、0.12 +/- 0.00和0.34 +/- 0.01 m/s。这跨越了先前的生理学研究的范围，其中发现PWV对HR的依赖性在0.08至0.10 m/s / 5次/分钟之间。因此，动脉壁的粘弹性可能有助于大动脉刚度随HR变化的机制。需要进行生理学研究来证实这一机制。新的和值得注意的是，本研究使用传输线模型来阐明动脉粘弹性在脉搏波速度对心率的依赖性中的作用。该模型使用分数粘弹性概念，为动脉血流动力学提供了新的见解。本研究也提供了一种评估脉搏波速度与心率相关性的临床表现的方法。
Experimental investigations have established that the stiffness of large arteries has a dependency on acute heart rate (HR) changes. However, the possible underlying mechanisms inherent in this HR dependency have not been well established. This study aimed to explore a plausible viscoelastic mechanism by which HR exerts an influence on arterial stiffness. A multisegment transmission line model of the human arterial tree incorporating fractional viscoelastic components in each segment was used to investigate the effect of varying fractional order parameter (alpha) of viscoelasticity on the dependence of aortic arch to femoral artery pulse wave velocity (afPWV) on HR. HR was varied from 60 to 100 beats/min at a fixed mean flow of 100 ml/s. PWV was calculated by intersecting tangent method (afPWV(Tan)) and by phase velocity from the transfer function (afPWVTF) in the time and frequency domain, respectively. PWV was significantly and positively associated with HR for alpha >= 0.6; for alpha = 0.6, 0.8, and 1, HR-dependent changes in afPWVTan were 0.01 +/- 0.02, 0.07 +/- 0.04, and 0.22 +/- 0.09 m/s per 5 beats/min; HR-dependent changes in afPWV(TF) were 0.02 +/- 0.01, 0.12 +/- 0.00, and 0.34 +/- 0.01 m/s per 5 beats/min, respectively. This crosses the range of previous physiological studies where the dependence of PWV on HR was found to be between 0.08 and 0.10 m/s per 5 beats/min. Therefore, viscoelasticity of the arterial wall could contribute to mechanisms through which large artery stiffness changes with changing HR. Physiological studies are required to confirm this mechanism.NEW & NOTEWORTHY This study used a transmission line model to elucidate the role of arterial viscoelasticity in the dependency of pulse wave velocity on heart rate. The model uses fractional viscoelasticity concepts, which provided novel insights into arterial hemodynamics. This study also provides a means of assessing the clinical manifestation of the association of pulse wave velocity and heart rate.