CHANGES IN TRANSMITRAL AND PULMONARY VENOUS FLOW PATTERNS IN THE FIRST DAY OF LIFE

The purpose of this study was to see the relationship between changes in pulmonary venous flow velocities and those in transmitral flow velo cities during the first day of life. A serial Doppler echocardiography was performed in 24 normal neonates at 2, 12, and 24 hours of age. Th e size of the ductus arteriosus was 4.3 +/- 0.5 mm at 2 hours and 2.1 +/- 0.7 mm at 12 hours, and closed in 21 of 24 neonates at 24 hours. T he peak systolic pulmonary venous flow (peak S), peak diastolic pulmon ary venous flow (peak D), peak D/S, peak velocity at early diastolic f illing (peak E), and peak E/A, which were high at 2 hours, decreased s ignificantly at 12 hours but remained constant thereafter. The size of the ductus arteriosus was found to be correlated with peak S, peak D, and peak D/S. There was a direct correlation between peaks E and D (r : 0.64, p < 0.01) as well as a direct correlation between peaks E/A an d D/S (r: 0.36, p < 0.05). These results indicate that the diastolic p ulmonary venous flow is determined by the same factors that influence the transmitral flow. These waveforms may reflect the increase in pulm onary circulatory volume by left-to-right shunting through the ductus arteriosus. (C) 1995 John Wiley and Sons, Inc.