正常胎儿肺静脉血流多普勒频谱分析及其临床意义

Analysis of pulmonary venous flow pattern in normal fetus by Doppler echocardiography

目的研究正常胎儿肺静脉血流频谱及其血流参数的正常参考范围.方法应用彩色多普勒超声诊断系统检测233例20～40孕周的正常胎儿的肺静脉血流频谱,测量其血流参数:心室收缩期峰值速度(S)、心室舒张期峰值速度(D)、心房收缩期速度(A)、时间速度积分(TVI),计算S/D、静脉峰值速度指数(PVI)、静脉搏动指数(PI).结果正常胎儿典型肺静脉血流频谱为三相波型:心室收缩期波峰、心室舒张期波峰及心房收缩期波谷, 前向血流持续整个心动周期.S、D、A及TVI 与胎龄呈良好的正相关,PVI、PI与胎龄呈良好的负相关,S/D与胎龄无明显相关关系.结论胎儿肺静脉血流频谱的产生主要由于左房与肺静脉之间的压差引起,左心房压力的改变有可能影响肺静脉血流频谱.胎儿肺静脉血流频谱及血流参数S、D、TVI 、PVI、 PI与孕周有良好的相关性.

Objective To describe the normal pulmonary venous blood flow velocity waveform and to establish reference ranges for fetus. Methods Two hundred and thirty-three normal singleton pregnancies between 20 and 40 weeks′ gestation were examined by Doppler echocardiography. In 209 fetuses, peak systolic velocity(S), peak diastolic velocity(D), end-diastolic velocity(A),and time velocity integral (TVI), S/D, pulsatility index for veins(PI), peak velocity index for veins (PVI) were calculated. Results The normal Doppler flow velocity waveform of the fetal pulmonary venous showed a pulsatile forward flow, consisting of a first peak during ventricular systole(S), a second peak during the early diastolic filling of the ventricular(D) and a minimum during atrial contraction(A). With advancing gestation, a significant increase in S,D,A,TVI was observed, whereas PVI,PI decreased significantly, S/D remained constant. Conclusions The fetal pulmonary venous flow velocity waveform patter is mainly affected by the left atrial pressure. The indexes change with advancing gestation.