Pulmonary blood velocity profile variability in open-chest dogs: influence of acutely altered hemodynamic states on profiles, and influence of profiles on the accuracy of techniques for cardiac output determination.
Pulmonary blood velocity profile variability in open-chest dogs: influence of acutely altered hemodynamic states on profiles, and influence of profiles on the accuracy of techniques for cardiac output determination.
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开胸狗的肺血速度曲线变异性：血流动力学状态急剧改变对曲线的影响，以及曲线对心输出量测定技术准确性的影响。
DOI：
10.1007/bf02058992
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发表时间：
1988
影响因子：
1.5
通讯作者：
Wilcox,BR
中科院分区：
文献类型：
--
作者：
Lucas,CL;Henry,GW;Ferreiro,JI;Ha,B;Keagy,BA;Wilcox,BR
临床研究的重点是寻找可用于定量肺血流和/或肺压力的无创肺血流速度测量的特征，其结果的不准确性通常归因于血流模式的可变性。为了确定体内动物模型在不同血流动力学状态下的血流模式可变性，使用20 mhz脉冲多普勒针探头记录了17只狗的主要肺动脉血流速度波形，沿前后壁方向轴每隔2mm记录一次。对照数据是在动物接受改变流量（心房水平分流）和压力（10% o2吸入）状态之前获得的。计算整个心动周期的瞬时速度曲线。肺血流的估计是在假设肺动脉的椭圆模型下得到的，该模型允许根据沿轴的测量值计算横断面上所有点的速度。将基于模型的估计值与实测值和以传统方式获得的估计值（即中心线速度与横截面积的乘积）进行比较。结果清楚地表明，即使在控制状态下，动物间也存在明显的差异。在收缩期晚期和舒张期早期观察到血管后半部分的反向流动，随着肺动脉压的升高而变得更加明显。相对于中线流速，肺血流升高倾向于增加沿前壁的最大流速。两种心输出量的估计结果都不一致准确（基于模型的方法r=0.77，面积乘以中心速度法r=0.80）。这项研究的发现强调了波形特征对采样地点的依赖性，受试者间的很大程度的可变性，以及需要大或多样本量来测定肺血流，这有助于澄清临床医生观察到的不一致，并表明未来的动物模型工作将有助于更好地理解人类肺速度波形的决定因素。
Clinical investigations focused on finding characteristics of noninvasively obtained measurements of pulmonary blood velocity that can be used to quantitate pulmonary blood flow and/or pulmonary pressure have often yielded results whose imprecision has been attributed to flow pattern variability. To determine flow pattern variability in an in vivo animal model in varying hemodynamic states, main pulmonary artery blood velocity waveforms were recorded in 17 dogs at 2-mm intervals along an anterior to posterior wall-oriented axis using a 20-MHz pulsed Doppler needle probe. Control data were obtained before the animals were subjected to altered flow (atrial level shunts) and pressure (10% O2inhalation) states. Instantaneous velocity profiles were computed throughout the cardiac cycle. Estimates of pulmonary blood flow were obtained assuming an elliptical model of the pulmonary artery which allowed computation of velocity at all points in the cross section, based on the measured values along the axis. Model-based estimates were compared to measured values and estimates obtained in the traditional fashion, i.e., the product of centerline velocity and cross-sectional area. Results clearly showed marked interanimal variability, even in control states. Reverse flow in the posterior half of the vessel, which tended to become more pronounced with increased pulmonary artery pressure, was observed during late systole and early diastole. Elevated pulmonary blood flow tended to increase the maximum velocities along the anterior wall relative to midline velocities. Neither estimate of cardiac output yielded consistently accurate results (r=0.77 for model-based method,r=0.80 for area times central velocity method). Findings of this study, which highlight the dependency of waveform characteristics on sampling site, the large degree of intersubject variability, and the need for large or multiple sample volumes for pulmonary blood flow determination, help clarify inconsistencies observed by clinicians and suggest that future work with animal models will facilitate a greater understanding of the determinants of human pulmonary velocity waveforms.