Stroke volume effect of changing arterial input impedance over selected frequency ranges.
Stroke volume effect of changing arterial input impedance over selected frequency ranges.
复制标题
在选定的频率范围内改变动脉输入阻抗对每搏输出量的影响。
DOI：
10.1152/ajpheart.1985.248.4.h477
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
Sagawa,K
中科院分区：
文献类型：
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作者：
Sunagawa,K;Maughan,WL;Sagawa,K
我们研究了在三个选定的频率范围内改变动脉输入阻抗对9只离体犬左心室每搏输出量（SV）的影响。输入阻抗用三元件Windkessel模型（即，电阻、特性阻抗和顺应性），并用伺服控制的加载系统施加在心室上。在恒定的舒张末期容积[33.1 +/- 1.5（SE）ml]下，我们在低频范围内改变后负荷阻抗的模量（低于0.13 Hz），通过改变电阻，在过渡频率范围内（其中阻抗模量从总电阻减小到特性阻抗），并且通过改变特性阻抗在高频范围（高于2.0Hz）上进行。将每个阻抗分量从对照改变为对照的50%和200%。随着低频阻抗模量的增加，SV敏感地从16.1 +/- 0.7降至7.4 +/- 0.5 ml。然而，在过渡频率范围（从11.2 +/- 0.6到12.3 +/- 0.7 ml）和高频范围（从11.9 +/- 0.6到11.6 +/- 0.7 ml）内，SV对阻抗模量的相同百分比增加相对不敏感。在这些频率范围内，SV对阻抗模量增加和减少的平均相对灵敏度为1.2：0.12：0.04。我们的结论是，在低频率范围内的阻抗模量是，到目前为止，比那些在过渡和高频率范围内的SV更重要的决定因素。
We investigated the effect of changing arterial input impedance over three selected frequency ranges on stroke volume (SV) in nine isolated canine left ventricles. The input impedance was simulated with a three-element Windkessel model (i.e., resistance, characteristic impedance, and compliance) and was imposed on the ventricles with a servo-controlled loading system. Under a constant end-diastolic volume [33.1 +/- 1.5 (SE) ml], we changed the modulus of the afterloaded impedance over a low frequency range (below 0.13 Hz) by changing the resistance, over a transitional frequency range (in which the impedance modulus decreases from total resistance to characteristic impedance) by changing the compliance, and over a high frequency range (above 2.0 Hz) by changing the characteristic impedance. Each of the impedance components was changed from control to 50 and 200% of control. SV sensitively decreased from 16.1 +/- 0.7 to 7.4 +/- 0.5 ml in response to the increase in the low-frequency impedance modulus. SV was relatively insensitive, however, to the same percent increase in the impedance modulus over the transitional frequency range (from 11.2 +/- 0.6 to 12.3 +/- 0.7 ml) and over the high frequency range (from 11.9 +/- 0.6 to 11.6 +/- 0.7 ml). The average relative sensitivities of SV to the increase and decrease in impedance moduli in these frequency ranges were 1.2:0.12:0.04. We conclude that the modulus of impedance in the low frequency range is, by far, a more important determinant of SV than those in the transitional and high frequency ranges.