Serial electrocardiograms recorded on one subject over a period of 42 years (1923-65).

A LONGITUDINAL STUDY OF THE RANGE OF NORMAL IN THE ELECTROCARDIOGRAM WAS CARRIED OUT, USING THE AUTHOR AS THE SUBJECT: 18 records were made in the course of 42 years (1923-1965). Only minor differences were demonstrated which are believed to represent differences in posture or in relation to meals, because the electrocardiograms were not recorded under standard basal conditions. The QRS was wider in the precordial than in the limb leads. The amplitude of T-waves varied within a range of 1-11.5 mv.