The relationship of the U wave to the 10-year incidence of myocardial infarction.

The relationship between the baseline electrocardiogram and 10-year incidence of myocardial infarction was examined in a cohort of 1013 men. The men were participants in the Normative Aging Study, a longitudinal study of aging initiated in 1963 at the Veterans Administration Outpatient Clinic in Boston, Massachusetts. Absence of the U wave among these men yielded a relative risk estimate of myocardial infarction of 2.7 as compared to men with a U wave present (95% confidence interval, 1.4-5.2). This association persisted when standard coronary risk factors (cholesterol, blood pressure, and cigarette smoking) were taken into consideration in a multivariate analysis. The results support the conclusion that an abnormality in the electrocardiogram considered to be of little importance indicates an increased risk of myocardial infarction independent of known coronary risk factors.