Quantitative Frank vectorcardiograms of normal children and a comparison to those of patients with atrial defects

Frank VCG's were subjected to detailed quantitative analysis for a large group of normal children, and a tabulation of normal values is presented. The values are based on examination of the vectors in the form of x, y, and z components. For children with secundum atrial septal defects, statistically significant differences from normal children were found throughout most of the QRS. From these measurements it was determined that easily measurable scalar lead variables Sx, Ry, and Sz were highly discriminating between the two categories, and an arbitrary method was defined for placement of an individual patient's vector into either the ASD or the normal category. The results indicate that application of such statistical methods, which do not require a computer, may be useful in differentiating diagnostic categories on an individual patient basis.