[Age-related changes of electrocardiographic wave].

Magnetocardiograms (MCGs) were recorded by means of a second-derivative SQUID (superconducting quantum interference device) magnetometer in 150 normal subjects (25-34 years old, 30 cases; 35-44 years old, 30 cases; 45-54 years old, 30 cases; 55-64 years old, 30 cases; 65-74 years old, 30 cases) to investigate whether cardiac current would change with age. Based on these MCG records at 36 points on the anterior chest wall, isomagnetic maps during QRS wave were constructed, and dipole moments was calculated mathematically. The amplitude of RV5 and SV1 + RV5 in ECG were larger in 65-74-year-old women compared to those in women of other ages, and SV1 + RV5 was smaller in 45-74-year-old men compared to those in 25-44-year-old men. However, dipole moments deduced from MCG did not differ with age. These results suggest that age-related changes in the amplitude of QRS wave in ECG do not affect the change in electromotive force with aging.