The Effect of Aging on Intervals, Axis, Heart Position, and Transitional Zone of Electrocardiogram

Author analysed ECG records of conventional 12 leads of 240 healthy persons (120 males and 120 females of 15-90 years of age) to evaluate the cardiac changes with advancing age and following results were obtained;

1. P-R intervals were not changed significantly with advancing age. The QT, Q-aT, Q-aU, and Q-U intervals were prolonged with advancing age and they were marked in male than female.

2. Mean QRS axis were shifted to the left with advancing age and these were more distinct in male than female. Mean P axis and mean T axis were not changed appreciably with advancing age.

3. The incidences of ECG position of vertical and semivertical heart position were decrease with advancing age and intermediate, horizontal and semihorizontal heart position were increased with advancing age.

4. The transitional zone of precordial leads were not changed with advancing age.