Computer interpretation of Frank vectorcardiogram in normal infant: Longitudinal and cross-sectional observations from birth to 2 years of age.

Abstract

The evolution of the Frank vectorcardiogram (VCG) was studied from longitudinal observations (60 normal infants) and from cross-sectional observations (231 normal infants) from birth to two years of age. Age specific normal values for the Cartesian coordinates of 14 vectors including maximal QRS-T and timed vectors in the horizontal and frontal plane were determined with both methods of analysis. In longitudinally followed infants the most significant involution of right ventricular forces occurred between the newborn period and 7-14 weeks of age. These changes included disappearance of clockwise horizontal loop rotation and a leftward shift of maximal and terminal forces as well as a rightward shift of initial vectors. Longitudinal observations were useful for prediction of the normal Frank VCG in the 7 to 14-week-old infant from values observed in the newborn period and for prediction of the horizontal loop rotation throughout infancy. Cross-sectional data showed a wider range of normal values than longitudinal data in the same 7 to 14-week-old infants, but age specific normal values were well reflected between 4 and 24 months of age from cross-sectional data.