Atrioventricular Flow Wave Patterns before and after Birth by Fetal Echocardiography

Doppler echocardiographic measurements of both valves during intrauterine life can be used to calculate peak early filling velocity (E)/late peak atrial filling velocity (A) ratio as a single index of diastolic performance. The purposes of this study were to estimate the changes in atrioventricular valve flow from gestational age 37-40 weeks to 1 month of postnatal life and to clarify the difference in right and left ventricular diastolic filling patterns.

Atrioventricular flow waves were analyzed in 24 full-term pregnant women by fetal echocardiography. Postnatal follow-up studies were performed at 1 hour, 6 hours, 24 hours, 3 days, 1 week and 1 month. In each time point, pulsed Doppler echocardiography was used to interrogate Doppler waveform of E velocity, A velocity, total area under the curve (time velocity integral) and heart rate.

Mitral E/A ratio significantly increased from 0.7 ± 0.1 before birth to 1.0 ± 0.3 at postnatal 1 hour, 1.0 ± 0.2 at 1 week, and 1.5 ± 1.0 at 1 month. Tricuspid flow E/A ratio was 0.8 ± 0.3 before birth, 0.8 ± 0.1 at 1 hour, 0.8 ± 0.2 at 3 days, 0.9 ± 1.0 at 1 month. Time velocity integral of tricuspid flow was significantly higher than that of mitral flow before birth, but there was no difference after birth.

The dominance of mitral A wave before birth was changed very quickly after birth to the dominance of E wave, but the dominance of tricuspid A wave was maintained at 1 month. Diastolic function and compliance of mitral valve were better than those of the tricuspid valve after birth.