1st Department of Medicine, Cardiology, Angiology, Pneumology, Intensive Care, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany.
Clin Cardiol. 2010 Feb;33(2):E8-14. doi: 10.1002/clc.20612.
USCOM, a novel continuous wave Doppler (CWD) device, has been introduced for noninvasive determination of cardiac output (CO). The present study aimed to compare the accuracy and reproducibility of the new device, using cardiovascular magnetic resonance imaging (CMR) as the noninvasive gold standard.
The CO of 56 consecutive patients was prospectively determined by CWD either before or after CMR imaging. The CWD probe was placed in the suprasternal or supraclavicular notch aiming at the aortic valve. Valid CWD signals could be obtained in 45 patients yielding a CO of 5.3+/-1.1 L/min (range, 3.0-7.5 L/min) by CMR and 4.7+/-1.1 L/min by CWD (2.5-8.0 L/min, P = .004), respectively. CWD measurements showed an acceptable agreement with CMR (bias: 0.6+/-1.1 L/min) and a high reproducibility (bias: 0.1+/-0.4 L/min). Higher CO and body mass index (BMI) were identified as sources of inaccuracy in univariate analysis. By multivariate analysis, only CO(CMR) was found to be independently associated with larger variation. Estimated diameters of the left ventricular outflow tract (LVOT), a prerequisite for CO measurement by CWD, correlated only weakly with those measured by CMR.
Continuous wave Doppler is a feasible technique for measuring cardiac function. Although the overall agreement with CMR was acceptable, CWD showed a trend to underestimate CO. The estimated LVOT diameter by CWD is likely to be an important source of error. Nevertheless, the CWD device could be of clinical use especially for detection of intraindividual hemodynamic changes since a high reproducibility could be demonstrated.
USCOM 是一种新型连续波多普勒（CWD）设备，已被引入用于无创性心输出量（CO）的测定。本研究旨在使用心血管磁共振成像（CMR）作为非侵入性金标准来比较新设备的准确性和可重复性。
连续 56 例患者前瞻性地通过 CWD 或 CMR 成像前或后确定 CO。CWD 探头置于胸骨上或锁骨上切迹处，旨在主动脉瓣。在 45 例患者中获得了有效的 CWD 信号，CMR 测量的 CO 为 5.3+/-1.1 L/min（范围 3.0-7.5 L/min），CWD 为 4.7+/-1.1 L/min（2.5-8.0 L/min，P =.004）。CWD 测量与 CMR 具有可接受的一致性（偏差：0.6+/-1.1 L/min），并且具有较高的可重复性（偏差：0.1+/-0.4 L/min）。在单变量分析中，较高的 CO 和体重指数（BMI）被确定为不准确的原因。在多变量分析中，仅 CMR 心输出量（CO）被发现与较大的变异性独立相关。CWD 测量 CO 的左心室流出道（LVOT）的估计直径仅与 CMR 测量的直径弱相关。
连续波多普勒是测量心功能的可行技术。尽管与 CMR 的总体一致性可接受，但 CWD 显示出低估 CO 的趋势。CWD 测量的 LVOT 直径可能是一个重要的误差源。然而，CWD 设备可能具有临床用途，特别是用于检测个体内的血流动力学变化，因为可以证明其具有较高的可重复性。
