正常胎儿的心脏血流动力学研究

Research on cardiac hemodynamics among normal fetuses

目的研究中晚孕期正常胎儿心脏二、三尖瓣血流特点,并探讨不同孕期血流特点的演变规律,为先天性心脏病的筛查提供更多依据。方法 146例孕19～40 w正常胎儿选为研究对象,脉冲多普勒(PWD)测量二、三尖瓣血流E峰、A峰,计算E/A值,把三尖瓣血流为单峰的分为组1,双峰的分为组2,比较两组间心率的差异。组2中把孕20～28 w分为A组,28～40 w分为B组,对A、B两组间及组内E峰、A峰、E/A进行比较,并对各观察指标随孕周的变化分别进行直线相关分析。结果组1的平均心率比组2高,两组间有统计学差异。A、B两组间,二尖瓣血流E峰、三尖瓣血流E峰、A峰及两组房室瓣的E/A值,B组均比A组高。二尖瓣血流A峰,A、B两组间无差异。在A、B两组组内,两组房室瓣血流A峰均高于E峰,三尖瓣血流的E峰、A峰、E/A值均高于二尖瓣。两组房室瓣的E峰、A峰及E/A值均随孕周的增加而增加,但A峰随孕周改变变化较小。结论确定正常中晚孕期胎儿二、三尖瓣血流E峰、A峰、E/A值的正常值范围,研究其在不同孕期的演变规律,可为胎儿心功能不全、先天性心脏病的筛查提供参考指标。

Objective To study the mitral and tricuspid valves blood flow characteristics of normal fetuses in the middle and late duration of pregnancy, and to discuss the developing regularity of blood flow in different duration of pregnancy in order to provide more evidences for the screening of congenital cardiopathy. Methods 146 cases of fetuses in 19 - 40 w of pregnancy were selected as subjects. Pulsed wave Doppler （PWD） was used to detect the E and A peak velocities of the mitral and tricuspid valves blood flow. The ratio of E to A was calculated. The cases with the single - peak of tricuspid valves blood flow were selected as group 1, and those with the double - peaks were selected as group 2. Comparison was made in the difference of heart rate between the two groups. In group 2, the cases in 20 - 28 w of pregnancy were chosen as group A, and those in 28 - 40 w of pregnancy were chosen as group B. Comparison was made in E and A peak velocities and the ratio of E to A between group A and B and among the cases in group 2. Line analysis was made in the correlation between those indicators and the gestational week. Results The average heart rate of group 1 was higher than that of group 2. The E peak velocity of the mitral valves blood flow, the E and A peak velocities of the tricuspid valves blood flow, and the ratio of E to A peak of atrioventricular valve blood flow in group B were all higher than those in group A. There was no difference in the A peak velocity between the two groups. Among the cases of group A and B, the A peak velocity of atrioventricular valve blood flow was higher than the E peak velocity flow, and the E and A peak velocities and the E to A ratio of tricuspid valve blood flow were all higher than those values of mitral valve blood flow. In the two groups, the E and A peak velocities and E to A ratio of atrioventricular valve all became higher along with the increase of gestational week, but the changes along with the gestation in the A peak velocity were much fewer. Conclusion Determining the normal range of the E and A peak velocities and the E to A ratio of the mitral and tricuspid valves blood flow for the normal fetuses in the middle and late pregnancy and studying the changing regularity in different gestation can provide reference for the screening of the fetuses＇ cardiac insufficiency and congenital heart disease.