Normal ranges of modified axial lead system electrocardiogram parameters.

Methods Two hundred and sixty-five normal male and female subjects whose ages ranged from 4 to 8o years were studied. Their age distribution stratified in three groups, up to I4 years, I5 to 29 years, 30 years and over, is shown in Table I. Each patient was assessed as normal on the basis of physical, radiological, and conventional 12 lead electrocardiographic examination. Three lead electrocardiograms were tape-recorded using standard FM techniques and replayed to a PDP-8 computer for analogue to