To date, no reference values have been provided for right and left atrial filling in normal children. The aim of our study, therefore, was to characterize measurements of superior caval, hepatic, and pulmonary venous flow using Doppler echocardiography in a large group of normal children to reflect the effects of age, body mass index, sex, heart rate and respiration.
Doppler echocardiographic examinations of the superior caval, hepatic and pulmonary veins were performed during inspiration and expiration in 72 healthy children with a mean age of 6.73 ± 5.10 years. The subjects were segregated into four age groups, namely infants <2 years, preschool children between the ages of 2 and 7 years, children of school age between 7 and 11 years, and adolescents older than 11 years.
Age has significant effect on the systolic and reverse atrial flows within the superior caval vein (p < 0.05). No change in the Doppler velocities was observed related to body mass index or sex. All peak systolic velocities decreased significantly during expiration (p < 0.05). This decrease was most prominent in the hepatic vein (26%), but less remarkable in the superior caval vein (5.7%) and the pulmonary veins (3.9%). During expiration, the peak diastolic flow in the superior caval and the hepatic veins decreased, while the reverse atrial flow in the hepatic vein increased (p < 0.05). Pulmonary venous velocities were similar in all age groups (p > 0.05). Except for the systolic pulmonary venous velocities, these parameters were not influenced by respiration (p > 0.05). The diastolic time, the interval between reverse atrial flow and ventricular systole reflected by the R wave on the electrocardiogram, and the interval between ventricular systole and diastolic flow, were negatively correlated with heart rate (p < 0.05; r = −0.35, −0.85, and −0.8 respectively), and positively correlated with age (p < 0.05; r = 0.3, 0.8, and 0.7 respectively). They were not influenced by respiration.
Our study provides data of the patterns and the normal ranges of velocities of superior caval, hepatic, and pulmonary venous flow in a series of normal children. The results can now be used for comparison with the patterns found in the setting of disease.