Since the introduction of coronary care units, the in-hospital mortality from acute myocardial infarction has stabilized at a respectable 15% to 20%. Prehospital mortality in this disease remains disconcertingly high, in the range of 25% to 40% of all episodes of acute myocardial infarction. This prehospital mortality represents 60% or more of the total mortality during the first month of illness.
Interest in the prehospital phase of this illness was dramatized by the mobile coronary care unit concept which was initiated in 1966. This approach initially focused attention on the emergency treatment of lifethreatening arrhythmias. As a byproduct, a considerable understanding of the variety and frequency of abrupt cardiac dysrhythmias in the early period after onset of acute myocardial infarction was obtained. Nevertheless, mobile ambulances have not had a major impact on this illness since most of the prehospital deaths from acute myocardial infarction are sudden and occur within the