多普勒超声对正常胎儿心脏机械性PR间期的临床研究

目的探讨多普勒超声对正常胎儿心脏机械性运动PR间期的检测方法。方法将受检胎儿300例分为早、中、晚孕3组，在标准胎儿左心室流人道及流出道切面上，运用彩色多普勒引导脉冲多普勒取样容积记录左心室流人道及流出道血流频谱，测量从舒张期二尖瓣A峰起始至收缩期主动脉射血起始的心房剑心窀的传导时间（PR问期），并同时测量收缩期主动脉射血起始至二尖瓣A峰开始的时间（VA间期）。结果胎儿孕周、心率、PR间期、VA间期的数值均呈正态分布，300例胎儿的平均孕周为（21．33±9．55）周，平均心率（152．34±10．83）次／min，平均PR间期（105．63±13．35）ms，平均VA间期（283．294±23．57）ms。不同孕期组间的孕周、胎儿心率、PR间期、VA间期的差异均有统计学意义（P=0．000），经SNK—q检验显示不同孕期组间两两差异均有统计学意义（P〈0．01）。结论应用多普勒超卢测量PR间期和VA间期方法简便，图像清晰且重复性好，该方法可对胎儿I度房室传导阻滞捉供诊断信息，并可对胎儿房室传导阻滞的防治和预后提供依据。

The clinical study of color Doppler ultrasonography on machnical P-R interval of healthy fetal heart

Objective To explore the healthy fetal heart with Doppler ultrasonography method of measuring P-R interval of machnical motion of Methods A total of 300 tested fetuses were classified into three groups： the first, second and third trimester. In standarded section of left fetal ventricular inflow and outflow tract, pulsed Doppler sampling unit was placed under the guidance of color Doppler to record the flow spectra in left ventricular inflow and outflow tract. Atrioventricular conduction time from the beginning of the A peak of mitral valve in diastole to the beginning of aorta ejection in contraction were measured, and the interval from the beginning of atria ejection to the beginning of the A peak of mitral valve was measured. Results The parameters of gestational weeks, heart rates, PR interval and VA interval of fetuses were normally distributed. The average gestation lasted 21.33 ± 9.55 week, the average heart rate was 152.34 ±10.83 bpm, the average PR interval was 105.63 ±13.35 ms and the average VA interval was 283.29 ± 23.57 ms. The significant differences were found in the parameters among the three different trimesters of pregnancy. The significant differences were found between every two different trimesters of pregnancy by SNK-q test as well. Conclusions The Doppler ultrasonography is convenient, clear and high reproducible method to measure P-R and VA interval, which may provide a diagnosis standard for fetal First-degree heart block and diagnostic evidence for prevention and judgement of fetal atrioventricular block.