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 $0.7{\pm}0.1$ before birth to $1.0{\pm}0.3$ at postnatal 1 hour, $1.0{\pm}0.2$ at 1 week, and $1.5{\pm}1.0$ at 1 month. Tricuspid flow E/A ratio was $0.8{\pm}0.3$ before birth, $0.8{\pm}0.1$ at 1 hour, $0.8{\pm}0.2$ at 3 days, $0.9{\pm}1.0$ 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.