Abstract：
Previous echocardiographic studies were mainly focused on preterm infants and early fetal-to-neonatal transition period, whereas little is known about changes in the parameters of the right ventricular (RV) function after 72 h of life. Our aim was to quantitatively characterize potential changes in RV function by echocardiography in healthy term newborns between the third and the seventh day of life. We conducted a prospective observational study in 35 full-term newborns, in whom we performed echocardiographic examinations on the third and the seventh day of life. We assessed RV function, output and afterload and found a significant increase in all tissue Doppler velocities as well as in RV longitudinal strain, a higher mean RV outflow tract velocity time integral and lower myocardial performance index (MPI\'), whereas the tricuspid annular plane systolic excursion, RV filling pattern, and RV outflow tract acceleration time were not significantly different between the third and the seventh day of life. Conclusions: Increased RV systolic and diastolic myocardial velocities, cardiac output and longitudinal deformation and decreased RV MPI\' between the third and the seventh day of life point to a reduction of RV afterload and adaptive myocardial maturation in term newborns during this period. Moreover, PW-TDI and 2D speckle-tracking echocardiography seem to be more sensitive for evaluating RV function in comparison with M-mode echocardiography and pulsed-wave Doppler analysis of RV filling.
摘要：
以前的超声心动图研究主要集中在早产儿和早期胎儿到新生儿过渡期，而对生命72小时后右心室（RV）功能参数的变化知之甚少。我们的目的是通过超声心动图定量表征健康足月新生儿在生命的第3天至第7天之间的RV功能的潜在变化。我们在35名足月新生儿中进行了一项前瞻性观察研究，我们在生命的第三天和第七天进行了超声心动图检查。我们评估了RV功能，输出和后负荷，并发现所有组织多普勒速度以及RV纵向应变显着增加，较高的平均RV流出道速度时间积分和较低的心肌性能指数(MPI)，而三尖瓣环平面收缩期偏移，RV填充模式，和RV流出道加速时间在第3天和第7天之间没有显著差异。结论：RV收缩期和舒张期心肌速度增加，在生命的第3天和第7天之间，心输出量和纵向变形以及RVMPI下降表明在此期间足月新生儿的RV后负荷和适应性心肌成熟减少。此外，与M型超声心动图和RV充盈的脉冲多普勒分析相比，PW-TDI和2D斑点追踪超声心动图似乎对评估RV功能更敏感。
