Diameters of the orifices of the aorta and pulmonary trunk in normal children--an angiocardiographic study.

The diameters of the orifices of the pulmonary trunk and aorta were measured from cineangiocardiographic films in 35 children (mean age 7 years and 6 months, mean height 124.3 cm) without heart disease. Measurements were obtained in the lateral projection in early systole. Calipers and a micrometer were used and the values were expressed to the nearest 0.5 mm. The measured size of the intracardiac catheter was used for calibration. The mean ratio of the squared diameters of the orifices was 1.22:1 (SD 0.17). The diameter of the orifice of the pulmonary trunk/100 cm of body height (14.0 +/- 2.0 mm) was greater than that of the aortic (12.7 +/- 2.0 mm) (P less than 0.01). Significant linear correlation was found between the diameter of the orifice of the pulmonary trunk and body height (r = 0.71, P less than 0.001), weight (r = 0.67, P less than 0.001), and surface area (r = 0.70, P less than 0.001). Similar correlations were found for measurements of the aortic orifice and body height (r = 0.70, P less than 0.001), weight (r = 0.71, P less than 0.001), and surface area (r = 0.71, P less than 0.001), and between the diameters of the two orifices themselves (r = 0.91, P less than 0.001). Body weight is more affected than body height in various types of congenital heart disease. The relationship of the sizes of the orifices of the pulmonary trunk and aorta to body height may therefore be more applicable than their relation to body weight and surface area.