Comparison Study Of Fetal Heart Conduction Time Intervals By Quantitative Tissue Velocity Imaging And Pulse Doppler Echocardiography

Objective:To assess the values of quantitative tissue velocity imaging in studying normal fetal heart conduction time intervals.Methods:Totally 78 fetuses between 17 and 41 week's gestation underwent detailed echocardiograms.Atrio-ventricular conduction time interval(AV) and the time interval from onset of ventricular contraction to the onset of atrial contraction of next cardiac cycle(VA) were measured by quantitative tissue velocity imaging(QTVI) and pulse Doppler(PD) echocardiography.Results:QTVI-AV was(119.44±7.00) ms(95%CI 117.86～121.01ms).QTVI-VA was 298.58±22.17 ms(95%CI 292.85～303.06 ms).PD-AV was 121.88±8.05 ms(95%CI 120.07～123.70ms).PD-VA was 295.58±22.17ms(95%CI 290.58～300.58 ms).2-tailed T test revealed no systematic difference between the 2 approaches used to measure AV and VA.Gestational age and AV intervals were positively correlated with all imaging modalities,and significantly negatively correlated with fetal heart rate.Conclusions:This study established the normal values of fetal heart conduction time intervals.The usage of QTVI in fetal heart conductional time intervals has important potential clinical utility in assessing fetal arrhythmia.