The Pre-Hospital Phase of Acute Myocardial Infarction

Abstract

A prospective interview study of the hospital arrival time (HAT) was obtained on 160 patients, aged 28 to 87 years, who were admitted with acute myocardial infarctions to cardiac care units in two Rochester hospitals. The median time between the onset of acute coronary symptoms and the patient's arrival in a hospital emergency department was 3½ hours. The distribution of the HAT was trimodal: group I (early arrivals), less than 4 hours from onset of symptoms, median, 2 hours, n = 89; group II (mid-arrivals), 4 to 14 hours, median, 6 hours, n = 45; group III (late arrivals), greater than 14 hours, median, 27 hours, n = 26. Three intervals were defined: a decision time, an unaccounted for time, and a transportation time. In the entire population, the decision time consumed the major portion (51%) of the HAT, and the unaccounted for time 35% of HAT. The transportation time, whether by ambulance or car, averaged 25 min (14% of HAT), and it made up a diminishing percentage of the HAT in the longer arrival groups. The HAT in groups I, II, and III and the decision time in groups I and II were scrutinized with regard to demographic data, past medical history, pre-hospital factors, and hospital course. The findings suggest that the psychologic makeup of the patient is a major factor in the decision making process and thus, in the duration of the HAT.