Pain in Acute Myocardial Infarction

In 261 consecutive patients admitted with a first or second acute myocardial infarction (AMI), a relationship was found between age, enzyme-estimated infarct size and the need for analgesics and the duration of pain. Patients with relatively low heart rate ( < 80 b.p.m), low systolic blood pressure ( < 160 mm Hg,) low rate-pressure product ( < 12,000) and definite ECG signs of AMI had a greater need for analgesics and a longer duration of pain, probably because of a larger infarct. A similar need for analgesics and a similar duration of pain were found in patients who developed complications during admission. The difference between our findings and those of previous studies may be explained by the fact that previous studies were based on the analysis of subgroups of patients, primarily selected for intervention studies.