Change in cardiac diastolic function in neonates.

In this study we used Doppler echocardiography to examine changes in ventricular diastolic function in neonates. Echocardiograms were performed in 25 healthy neonates at 1-6 days (2.7+/-1.6 days) and at 25-35 days (29.4+/-3.3 days) after birth. Ventricular inflow velocity curves were recorded using the pulsed-Doppler method. Peak velocities (peak E, A). mean velocities (mean E, A), times (time E, A), and diastolic velocity-time integrals (area E, A) were measured during both early ventricular filling and atrial systole. The acceleration time of the wave during early ventricular filling was also measured. Peak E and A and mean E and A in both ventricles increased at 1 month after birth. Acceleration times in both ventricles were shortened. The ratio of area E to A in both ventricles and of peak E to A in the left ventricle did not change at 1 month after birth. Only the ratio of peak E to A in the right ventricle increased. The ratio of peak E to (area E + area A), which is thought to be a load-independent index, increased in both ventricles. The authors concluded that ventricular relaxation appears to increase in both ventricles, 1 month after birth, and that changes in diastolic function occur even in neonates.