Robson S C, Murray A, Peart I, Heads A, Hunter S
Department of Paediatric Cardiology, Freeman Hospital, Newcastle upon Tyne.
Br Heart J. 1988 Jun;59(6):680-4. doi: 10.1136/hrt.59.6.680.
The variability of Doppler echocardiographic estimation of cardiac output at the aortic orifice was investigated in eight healthy subjects. Cross sectional echocardiograms of the aortic orifice and aortic Doppler velocities were recorded and measured by four echocardiographers. Between subject variability was significantly larger than within subject variability for all variables. Variability owing to different echocardiographers and different measurement times was small compared with total variability. Coefficients of variation for aortic annular diameter, aortic velocity integral, and heart rate were 4.1%, 6.4%, and 5.0% respectively. The coefficient of variation for cardiac output was 8.8% and the 95% confidence interval for measurement of cardiac output by the Doppler method was 4.45 to 6.35 l/min. One echocardiographer reanalysed all the recordings and the results showed that recording the echocardiograms introduces a significantly larger source of error than measuring them. Thus serial measurements of cardiac output by the Doppler method can be performed with acceptable reproducibility; this indicates that the technique can be accurately applied in clinical practice.
对8名健康受试者进行了研究，以探讨经主动脉口的多普勒超声心动图心输出量估计值的变异性。4名超声心动图医师记录并测量了主动脉口的横截面超声心动图和主动脉多普勒速度。所有变量的受试者间变异性显著大于受试者内变异性。与总变异性相比，不同超声心动图医师和不同测量时间导致的变异性较小。主动脉环直径、主动脉速度积分和心率的变异系数分别为4.1%、6.4%和5.0%。心输出量的变异系数为8.8%，多普勒法测量心输出量的95%置信区间为4.45至6.35升/分钟。一名超声心动图医师重新分析了所有记录，结果显示，记录超声心动图引入的误差源比测量它们时大得多。因此，采用多普勒法连续测量心输出量具有可接受的重复性；这表明该技术可在临床实践中准确应用。
