Growth of the internal diameters in the pulmonary arterial tree in infants and children.

To provide a better understanding of the operability of the pulmonary arteries in children with tetralogy of Fallot or with pulmonary atresia, we investigated the growth of the internal diameters of the pulmonary arterial tree in fresh postmortem hearts and great arteries of infants and children of ages up to 10 years after birth, who died from non-vascular diseases. Linear correlations were found between, on the one hand, the internal diameters of the pulmonary ostium, pulmonary trunk and left and right pulmonary artery and, on the other, body length. Based on an approach used in clinical studies we also determined the ratios between the internal diameter of the pulmonary arterial tree and the ascending aorta and also the ratios of the internal diameters of the descending aorta and the sum of the size of the left and right pulmonary arteries. Comparison of the data from the postmortem material with observations on the internal diameters measured with two dimensional (sector) echocardiography echo indicates that the latter may slightly underestimate the true diameters.