Ahmad M, Blomqvist C G, Mullins C B, Willerson J T
Aviat Space Environ Med. 1977 Jun;48(6):512-5.
The purpose of this study was to characterize the response of the human left ventricle to lower body negative pressure (LBNP) and to delineate the relation between left ventricular function and hemodynamic response. Ventricular function curves relating stroke volume to end-diastolic volum were obtained in 12 normal men. Volume data were derived from echocardiographic measurements of left ventricular end-systolic and end-diastolic diameters at rest and during LBNP at -40 mm Hg. End-diastolic volume decreased by 19% (p less than 0.01) and stroke volume by 22% (p less than 0.05). There were no significant changes in heart rate, arterial blood pressure, or end-systolic volume. Thus, moderate levels of LBNP significantly reduce preload and stroke volume, i.e. produce a Starling effect, without affecting contractile state. The absence of significant changes in heart rate and arterial blood pressure in the presence of a significant reduction in stroke volume is consistent with an increase in systemic peripheral resistance medicated by low-pressure baroreceptors.
本研究的目的是描述人体左心室对下体负压（LBNP）的反应特征，并阐明左心室功能与血流动力学反应之间的关系。在12名正常男性中获得了将每搏输出量与舒张末期容积相关联的心室功能曲线。容积数据来自于静息状态及-40mmHg下体负压时左心室收缩末期和舒张末期直径的超声心动图测量。舒张末期容积下降了19%（p<0.01），每搏输出量下降了22%（p<0.05）。心率、动脉血压或收缩末期容积无显著变化。因此，中度水平的下体负压显著降低前负荷和每搏输出量，即产生斯塔林效应，而不影响收缩状态。在每搏输出量显著降低的情况下心率和动脉血压无显著变化，这与低压压力感受器介导的全身外周阻力增加是一致的。
