Chair of Gynecology and Obstetrics, Faculty of Medicine, Jagiellonian University Medical College, Cracow, Poland.
Ultrasound Laboratory, ARS MEDICA Specialist Gynecology and Obstetrics Clinic, Tarnow, Poland.
J Ultrasound Med. 2024 Jul;43(7):1319-1331. doi: 10.1002/jum.16456. Epub 2024 Apr 3.
The aim of the study was to compare left ventricle stroke volume in healthy, eutrophic fetuses in the 2nd and 3rd trimesters evaluated using the velocity time integral and aortic annulus area with left ventricular stroke volume measured using Simpson's single-plane rule and to determine the discrepancy equation.
The study included 354 fetuses. In each fetus, during the same examination, simultaneous assessment of stroke volume was performed by pulsed-wave Doppler using the product of the velocity time integral and aortic annulus area and by the fetalHQ® software using Simpson's single-plane rule. The Mann-Whitney U test was used to compare the "product-derived" stroke volume and stroke volume using fetalHQ® software values in the 2nd and 3rd trimesters separately. The agreement between the two methods were verified using Bland-Altman analysis. A linear regression model was used to obtain the discrepancy equation.
In the 2nd trimester, the mean percentage difference between both the techniques showed that the stroke volume values determined using pulsed-wave Doppler were, on average, 88% higher than the stroke volume values determined using fetalHQ®. The upper limit of agreement between the compared techniques was approximately 146% and the lower limit of agreement was equal to 29.6%. In the 3rd trimester, the results indicated that the stroke volume values determined using pulsed-wave Doppler were, on average, 76% higher than the stroke volume values determined using fetalHQ®. The upper limit of agreement between the compared techniques was approximately 129% and the lower limit of agreement was 23%. Based on the results of the linear regression models, discrepancy formulas of the stroke volume values were obtained. The equations to calculate the predicted mean and standard deviations were used to compute the reference intervals for the mean, 5th and 95th centiles.
The calculation of left ventricular stroke volume using pulsed Doppler has higher result in relation to stroke volume determined using Simpson's rule significantly. The aortic annulus area showed a higher correlation regarding stroke volume than the velocity time integral in both the 2nd and 3rd trimesters. Stroke volume increased with the increase in aortic annulus area, whereas the velocity time integral remained relatively constant. The retrospective analysis of the collected material enabled the determination of the discrepancy equation.
本研究旨在比较健康、匀称胎儿在第 2 至 3 孕期中通过速度时间积分和主动脉瓣环面积计算左心室每搏量与通过 Simpson 单平面法测量左心室每搏量的差异，并确定差异方程。
该研究纳入了 354 名胎儿。在每例胎儿中，在同一检查中，通过脉冲波多普勒同时评估每搏量，使用速度时间积分和主动脉瓣环面积的乘积以及使用胎儿 HQ®软件通过 Simpson 单平面法进行评估。分别在第 2 和第 3 孕期中使用 Mann-Whitney U 检验比较“乘积法”和胎儿 HQ®软件计算得出的每搏量值。使用 Bland-Altman 分析验证两种方法之间的一致性。使用线性回归模型获得差异方程。
在第 2 孕期，两种技术之间的平均百分比差异表明，通过脉冲波多普勒确定的每搏量值平均比通过胎儿 HQ®软件确定的每搏量值高 88%。比较技术之间的上限差异约为 146%，下限差异等于 29.6%。在第 3 孕期，结果表明，通过脉冲波多普勒确定的每搏量值平均比通过胎儿 HQ®软件确定的每搏量值高 76%。比较技术之间的上限差异约为 129%，下限差异为 23%。基于线性回归模型的结果，获得了每搏量值的差异公式。使用预测平均值和标准差的公式计算了平均值、第 5 百分位数和第 95 百分位数的参考区间。
使用脉冲多普勒计算左心室每搏量的结果明显高于使用 Simpson 法则计算的每搏量。在第 2 和第 3 孕期中，主动脉瓣环面积与每搏量的相关性均高于速度时间积分。每搏量随着主动脉瓣环面积的增加而增加，而速度时间积分则相对保持不变。对收集材料的回顾性分析使得能够确定差异方程。
