PREVALENCE, CLINICAL-FEATURES, AND ACUTE COURSE OF ATYPICAL MYOCARDIAL-INFARCTION

Ninety-four consecutive patients (60 men and 34 women; mean age 68.5+/ -11.5 years) with acute myocardial infarction (MI) were investigated r etrospectively, in order to evaluate the prevalence, clinical features , and short-term course of the atypical forms (symptoms other than che st pain). An atypical MI was found in 30 patients, with a prevalence o f 32% (95% confidence limits 27-36%). It was most prevalent in women a bove sixty-five years old (P < 0.05). Abdominal pain, paroxysmal dyspn ea, and pulmonary edema were the most frequent symptoms (33%, 17%, 13% , respectively). No differences were observed between typical and atyp ical MI in regard to risk factors (hypercholesterolemia, arterial hype rtension, diabetes mellitus, cigarette smoking) and history of MI, cer ebrovascular disease, peripheral vascular disease, or chronic lung dis ease. Significantly fewer patients with atypical MI had a history of a ngina pectoris (P < 0.05). No differences were observed in regard to p revious medication, except for antiarrhythmic drugs, more often used b y atypical patients (P < 0.05). Location and severity of MI (as judged by ECG and peak levels of creatine kinase in the serum) were similar in both subgroups, as were the complications (34% typical and 50% atyp ical) and death rate (12.5% and 16.7%, respectively). In conclusion, a typical MI is not less severe than typical. This emphasizes the need f or a high suspicion index in many different clinical settings, but par ticularly (although not exclusively) in elderly females, in the presen ce of abdominal pain or otherwise unexplained paroxysmal dyspnea.