Electrocardiographic Findings Among the Adult Population of a Total Natural Community, Tecumseh, Michigan

Electrocardiograms were recorded from 2,449 men and 2,689 women past 16 years of age, 85 per cent of the adult population of Tecumseh, Michigan. The tracings were classified according to the system of Blackburn and associates and the various categories are tabulated and discussed. Abnormal Q waves and certain "nonspecific" changes such as left axis deviation, high-amplitude R waves, ST-segment depression, T-wave inversion, first-degree atrioventricular block, complete intraventricular block, and arrhythmias increased in frequency with age. Hypertension and hyperglycemia occurred with significant frequency among persons with some of these changes. It seems likely that such "nonspecific" electrocardiographic abnormalities are frequently signs of coronary or hypertensive heart disease. The mean amplitudes of QRS complexes of men less than 50 years of age were greater than those of women. Such sex differences should be taken into account in the interpretation of clinical electrocardiograms. Further examinations and surveillance of the participants of this study are expected to clarify the significance of the electrocardiographic features discussed and the relationships between such features and other physiologic variables.