Relationship of Premature Systoles to Coronary Heart Disease and Sudden Death in the Tecumseh Epidemiologic Study

Electrocardiograms were recorded on 5,129 persons aged 16 and over in Tecumseh, Mich. Premature systoles occurred in 264 individuals (5.1%); they were ventricular in 70% and supraventricular in 30%. The prevalence of both supraventricular and ventricular premature systoles increases with age. They occur more often in men than women. Ventricular premature systoles were correlated with coronary heart disease. Among persons over 30 years of age, 158 per 1,000 (26/165) of those with ventricular premature systoles had manifest coronary heart disease as compared with 50 per 1,000 (173/3,459) without premature systoles (P < 0.05). During a 6-year period 45 persons died suddenly (within 1 hr of onset of symptoms); 10 (22%) demonstrated ventricular premature systoles long before the fatal attack. Of 165 persons over age 30 with ventricular premature systoles, 10 died suddenly (61 per 1,000) compared with 35 of 3,459 (10 per 1,000) without this finding (P < 0.01). Supraventricular premature systoles are not associated with higher prevalence of coronary heart disease or increased risk of sudden death. The increased prevalence of coronary heart disease and incidence of sudden death in persons with antecedent ventricular premature systoles are independent of several known coronary risk factors—that is, blood pressure, serum cholesterol, relative weight, glucose tolerance, and smoking habits.