Winberg P, Jansson M, Marions L, Lundell B P
Department of Paediatrics, Karolinska Institute, Sachs' Children's Hospital, Stockholm, Sweden.
Arch Dis Child. 1989 Oct;64(10 Spec No):1374-8. doi: 10.1136/adc.64.10_spec_no.1374.
Left ventricular output was measured non-invasively at predefined time intervals from less than 15 minutes to 72 hours after birth in 16 infants who had been born at full term. The blood flow velocity in the ascending aorta was measured by a range gated Doppler technique and multiplied by the cross sectional diameter measured by cross sectional and M mode echocardiography. Left ventricular output remained high in the first two hours, 235-243 ml/min/kg, despite a 10% decrease in heart rate. The fall in heart rate was compensated for by a 15% increase in stroke volume. Between 2 and 24 hours there was a significant fall in mean (SD) left ventricular output to 187 (35) ml/min/kg caused mainly by a reduction in stroke volume. The fall in left ventricle output after two hours may reflect an adaptation to the decreased demand on the left ventricle as the ductus constricts.
对16名足月出生的婴儿在出生后不到15分钟至72小时的预定时间间隔内进行了无创左心室输出量测量。采用距离选通多普勒技术测量升主动脉内的血流速度，并乘以通过横截面和M型超声心动图测量的横截面直径。尽管心率下降了10%，但在前两小时左心室输出量仍保持较高水平，为235 - 243毫升/分钟/千克。心率下降通过每搏输出量增加15%得到补偿。在2至24小时之间，平均（标准差）左心室输出量显著下降至187（35）毫升/分钟/千克，主要原因是每搏输出量减少。两小时后左心室输出量下降可能反映了随着动脉导管收缩，左心室需求减少后的适应性变化。
