Atrioventricular Flow Wave Patterns before and after Birth by Fetal Echocardiography

BACKGROUND 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. METHODS 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. RESULTS 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. CONCLUSION 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.