Mielke G, Benda N
Department of Obstetrics and Gynecology, University of Tuebingen, Tuebingen, Germany.
Circulation. 2001 Mar 27;103(12):1662-8. doi: 10.1161/01.cir.103.12.1662.
The objectives of this study were to establish reference ranges for left and right cardiac output and to investigate blood flow distribution through the foramen ovale, ductus arteriosus, and pulmonary bed in human fetuses.
A prospective study was performed in 222 normal fetuses from 13 to 41 weeks of gestation with high-resolution color Doppler ultrasound. Cardiac output and ductal flow were calculated by use of vessel diameter and the time-velocity integral. Pulmonary blood flow was expressed as the difference between right cardiac output and ductal flow. Foramen ovale flow was estimated as the difference between pulmonary flow and left cardiac output. Gestational age-specific reference ranges are given for left, right, and biventricular output and volume of ductal blood flow, showing an exponential increase with gestational age. Median ratio of right to left cardiac output was 1.42 and was not associated with gestational age. Right cardiac output was 59% and left cardiac output was 41% of biventricular cardiac output. Median biventricular cardiac output was estimated to be 425 mL. min(-1). kg(-1) fetal weight. Ductal blood flow was 46%, estimated pulmonary flow was 11%, and estimated foramen ovale flow was 33% of biventricular output.
The study establishes reference ranges for fetal cardiac output and offers insights into the central blood flow distribution in human fetuses from 13 weeks to term. There is a clear right heart dominance. The estimated ratio of pulmonary blood flow to cardiac output is higher than in fetal lamb studies.
本研究的目的是建立左右心输出量的参考范围，并研究人类胎儿卵圆孔、动脉导管和肺床的血流分布。
对222例孕13至41周的正常胎儿进行前瞻性研究，采用高分辨率彩色多普勒超声。通过血管直径和时间-速度积分计算心输出量和导管血流。肺血流量表示为右心输出量与导管血流的差值。卵圆孔血流估计为肺血流量与左心输出量的差值。给出了不同孕周的左、右和双心室输出量以及导管血流量的参考范围，显示其随孕周呈指数增加。右心输出量与左心输出量的中位数比值为1.42，与孕周无关。右心输出量占双心室心输出量的59%，左心输出量占41%。双心室心输出量中位数估计为425 mL·min⁻¹·kg⁻¹胎儿体重。导管血流量占双心室输出量的46%，估计肺血流量占11%，估计卵圆孔血流量占33%。
本研究建立了胎儿心输出量的参考范围，并深入了解了孕13周直至足月的人类胎儿的中心血流分布。存在明显的右心优势。估计的肺血流量与心输出量的比值高于胎羊研究中的比值。
