Effect of age on the heart electrical phenomena, left ventricular wall thickness and blood pressure in men.

The effect of age on the maximal spatial QRS vector (MSQRSV) in the Frank lead system was correlated with th posterior left ventricular wall thickness (PLVWT), the interventricular septum thickness (IVST) determined by echocardiography, and with blood pressure in 300 normal men, distributed by age groups (20-29, 30-39, 40-60). With advancing age, a significant decrease of MSQRSV accompanied by a significant increase of PLVWT was observed while the increase of IVST and of blood pressures with age were found non significant. It was concluded that: 1. blood pressure is not the sole determinant of hypertrophy; 2. myocardial hypertrophy is not the sole determinant of cardiac voltage increase; 3. there is some degree of myocardial sclerosis in healthy people aged over 40-60 years; 4. in left ventricular hypertrophy the left ventricular muscular mass cannot be accurately predicted from the heart electrical phenomena; 5. the results obtained were in agreement with those of authors describing different aspects of normal Frank ECG and vectorcardiogram (VCG) in subjects under and over 40-50 years of age; 6. the variability of the degree of age influence on normal ECG from one country to another could explain the different diagnostic criteria for the same cardiac disease in computerized programs.