Jellema W T, Imholz B P, Oosting H, Wesseling K H, van Lieshout J J
Department of Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands.
Clin Auton Res. 1999 Aug;9(4):185-92. doi: 10.1007/BF02330482.
The aim of this study was to compare beat-to-beat changes in stroke volume (SV) estimated by two different pressure wave analysis techniques during orthostatic stress testing: pulse contour analysis and Modelflow, i.e., simulation of a three-element model of aortic input impedance.
A reduction in SV was introduced in eight healthy young men (mean age, 25; range, 19-32 y) by a 30-minute head-up tilt maneuver. Intrabrachial and noninvasive finger pressure were monitored simultaneously. Beat-to-beat changes in SV were estimated from intrabrachial pressure by pulse contour analysis and Modelflow. In addition, the relative differences in Modelflow SV obtained from intrabrachial pressure and noninvasive finger pressure were assessed.
Beat-to-beat changes in Modelflow SV from intrabrachial pressure were comparable with pulse contour measures. The relative difference between the two methods amounted to 0.1+/-1% (mean +/- SEM) and was not dependent on the duration of tilt. The difference between Modelflow applied to intrabrachial pressure and finger pressure amounted to -2.7+/-1.3% (p = 0.04). This difference was not dependent on the duration of tilt or level of arterial pressure.
Based on different mathematical models of the human arterial system, pulse contour and Modelflow compute similar changes in SV from intrabrachial pressure during orthostatic stress testing in young healthy men. The magnitude of the difference in SV derived from intrabrachial and finger pressure may vary among subjects; Modelflow SV from noninvasive finger pressure tracks fast and brisk changes in SV derived from intrabrachial pressure.
本研究旨在比较在体位性应激测试期间，通过两种不同的压力波分析技术估计的每搏输出量（SV）的逐搏变化：脉搏轮廓分析和模型流，即主动脉输入阻抗的三元模型模拟。
通过30分钟的头高位倾斜动作，使8名健康年轻男性（平均年龄25岁；范围19 - 32岁）的SV降低。同时监测肱内压和无创手指压力。通过脉搏轮廓分析和模型流从肱内压估计SV的逐搏变化。此外，评估从肱内压和无创手指压力获得的模型流SV的相对差异。
从肱内压获得的模型流SV的逐搏变化与脉搏轮廓测量结果相当。两种方法之间的相对差异为0.1±1%（平均值±标准误），且不依赖于倾斜持续时间。应用于肱内压和手指压力的模型流之间的差异为 - 2.7±1.3%（p = 0.04）。这种差异不依赖于倾斜持续时间或动脉压水平。
基于人体动脉系统的不同数学模型，在年轻健康男性的体位性应激测试期间，脉搏轮廓和模型流从肱内压计算出的SV变化相似。从肱内压和手指压力得出的SV差异大小可能因个体而异；来自无创手指压力的模型流SV能够追踪来自肱内压的SV的快速变化。
