Doppler echocardiographic evaluation of right and left ventricular diastolic function in normal neonates

Abstract

Doppler echocardiograms of the tricuspid and mitral valves were recorded along with the electrocardiogram and respiration in 22 normal full-term neonates. A computer-interfaced digitizer pad was utilized to measure the following: peak E and A velocities (cm/s); E and A areas (the components of the total velocity-time integral in the early passive period of ventricular filling [E] and the late active period of atrial emptying [A], respectively) and the 1/3 area fraction (or the proportion of filling in the first 1/3 of diastole).All of the variables of right (tricuspid) versus left (mitral) ventricular filling were significantly different on the 1st day of life. Respective values were peak E velocity (cm/s) 44.6 ± 10.0 (tricuspid) versus 53.2 ± 9.3 (mitral), p < 0.01 peak E/A ratio 0.84 ± 0.14 versus 1.15 ± 0.17, p < 0.0001; E/total area 0.58 ± 0.07 versus 0.63 ± 0.05, p < 0.0005; area ratio 1.05 ± 0.23 versus 1.63 ± 0.40, p < 0.0001; 1/3 area fraction 0.31 ± 0.04 versus 0.41 ± 0.04, p < 0.0001; peak A velocity (cm/s) 53.0 ± 8.4 versus 47.6 ±5.8, p s< 0.05 and A/total area 0.57 ± 0.09 versus 0.41 ± 0.09, p s< 0.001; the mean heart rate (beats/min) was not significantly different: 121 ± 8 versus 120 ± 7. Most of the variables remained significantly different on the 2nd day of life, but the level of significance was the same or less for all measurements.Doppler-determined diastolic function in neonates is significantly different for the right and left ventricle, particularly on the 1st day of life. The pattern of right ventricular diastolic function is characterized by a reduction in early passive filling, with a greater dependence on atrial contraction for right ventricular filling. These changes may reflect reduced right ventricular compliance as a result of intrauterine dominance.