[Echocardiography determination of the diameter of the heart and great vessels near the heart and their quotients in the newborn infant and infant].

110 infants aged from one to 384 days without cardiovascular diseases were examined by two-dimensional echocardiography. Their body weights were 2.4 to 10 kg. Using mechanical, angular scanheads of 7.5 and 5.0 MHz, the parasternal long and short axes views, the apical long axis view, the suprasternal long and short axes views and the subxiphoidal position was searched. Long axis and short axis of the left ventricle were measured at end-diastole and at end-systole. Aorta, pulmonary artery trunk, left and right pulmonary arteries and the roots of both coronary arteries were measured off-line at end-diastole. To confirm the measurements a) vertical and horizontal diameters of orthogonal transected vessels were measured, b) some vessel diameters were measured in different views and c) 10 infants were examined by two independent observers. The result of this inter-observer examination had an agreement of 77% in the 370 measurements and an inter-observer variability of 2.4%. The measured diameters were linearily related to body weight and BSA in this age group. Also, the calculated areas and volumes of the left ventricle related linearily to body weight and BSA. To simplify the estimation of left ventricular volume a formula was derived id est: Volume of left ventricle = 9.15 x greatest short axis x greatest long axis -20. The following quotients are independent from age, body weight, height, and BSA: Pulmonary artery root/aortic root, pulmonary artery bifurcation/aortic root, pulmonary artery bifurcation/-root, left atrium/aortic root.(ABSTRACT TRUNCATED AT 250 WORDS)