Relationship of the dimension of cardiac structures to body size: an echocardiographic study in normal infants and children

Normalization of the dimensions of cardiac structures to the size of the bo dy, using so-called Z scores, is becoming increasingly common in the manage ment of infants and children with congenital heart disease. Current publish ed nomograms for the ascertainment of Z scores for cardiac structures in ch ildhood are based largely on normal data obtained in formalin-fixed hearts. Since decisions concerning management are frequently based on the findings of cross-sectional echocardiograms, the dimensions of 15 cardiac structure s were measured using cross-sectional echocardiography in 125 normal infant s and children. Regression equations were derived relating cardiac dimensio ns to the size of the body. The expression of size with the highest correla tion to cardiac dimensions was body surface area. Nomograms were then devel oped from which the Z score of a cardiac structure could be estimated from a knowledge of the body surface area and the echocardiographically derived measurement.