HEART RATE: A PREDICTOR OF EARLY MORTALITY IN PATIENTS WITH MYOCARDIAL INFARCTION

A number of epidemiologic studies have reported a positive relationship between heart rate, cardiovascular disease and mortality. To examine the correlation between heart rate and mortality after acute myocardial infarction (AMI), 2147 patients hospitalized in coronary care units in Isfahan were investigated in a cross-sectional study. Their heart rate was measured according to an electrocardiograph obtained during the 2nd, 5th and final days of hospitalization, and all patients were followed for cardiovascular mortality. The means of3 measurements were divided into four fractions. A strong positive relationship between heart rate and cardiovascular mortality was obtained. Confounding variables such as age, sex, type of infarction and drugs were adjusted by regression models. The nonlinear regression relationship was due primarily to a sharp increase in mortality in the highest quartile of heart rate. We conclude that although sinus tachycardia can be considered as a predictive independent risk factor for mortality after AMI, further longitudinal studies are required.