Contribution of electrocardiograms, serum enzymes and history of chest pain to the diagnosis of acute myocardial infarction--a community-based register study in North Karelia, Finland, 1972-1981.

The contribution of electrocardiograms, serum enzymes and history of chest pain to the diagnosis of acute myocardial infarction (AMI) was examined in a series of 3123 persons with a definite acute myocardial infarction registered in a community-based myocardial infarction register study in North Karelia, eastern Finland in 1972-1981. Criteria for chest pain history, serum enzyme and electrocardiographic findings were those used in the WHO co-ordinated myocardial infarction register studies. The history of chest pain typical of AMI was obtained in approximately 90% of both men and women in all age groups. Among persons with first AMI, the proportion of unequivocal ECG changes was higher among men than in women and declined with age in both sexes (81.8% in men 20-44 years of age, 47.8% in men 75 years of age or more; 61.7% in women 20-54 years of age and 45-6% in women 75 years of age or more) and lower among persons with recurrent AMI, but even among them it decreased with age. The proportion of serum enzyme elevations was approximately 90% in all subgroups. The results of the present study reconfirm that the contribution of elevated serum enzymes is particularly important in patients with recurrent acute myocardial infarction and old age. Elevated serum enzymes should receive greater attention in surveillance studies aiming to detect trends in AMI incidence in populations.