The effect of age on the electrocardiogram

Abstract

There are significant electrocardiographic age trends in adult healthy populations from the third to the fifth decade in QRS and T amplitudes (decrease with age) and direction (left axis shift with age) in conventional electrocardiographic leads, which flatten out after age 50. The decrease of amplitudes is more pronounced in men than in women. Age trends of intervals are absent or small. However, the incidence of premature supraventricular and ventricular beats increases with age. Overweight accelerates the age trends. Diagnostic implications are discussed, particularly for recognition of left ventricular hypertrophy. Magnitudes and directions of maximal spatial QRS and T vectors show age trends similar to comparable conventional electrocardiographic items. Initial spatial 20 msec vectors also decrease with age; therefore, “poor progression of the R wave in the anterior chest leads”, often interpreted as compatible with anterior wall myocardial infarction, is a normal age trend. In the majority of studies, the effect of age is more pronounced in populations with high prevalence of coronary artery disease than in populations with low incidence. Coronary artery disease, as long as the resting electrocardiogram is normal, accelerates the age trends. The frequency of ischemic response to exercise is greater, with more pronounced age trends, in populations with high prevalance of coronary artery disease. It is concluded that the electrocardiographic age trends in asymptomatic populations are to a large extent due to latent coronary artery disease.