Acute and Subacute Coronary Insufficiency

The term " acute coronary insufficiency " has become increasingly familiar since it was properly described as an entity by Master and his colleagues in 1947.It may be defined as a state in which the coronary circulation is insufficient to meet the full metabolic demands of the myocardium at rest.yet sufficient to prevent myocardial infarction.The modified title of this paper was chosen to emphasize the prolonged course of the illness in one-half of the patients.Thus in the 150 cases studied the illness was acute, lasting less than six weeks, in 50% ; subacute, lasting between two and six months, in 45%; and chronic in 5%.Characteristically this transient physiological state arises spontaneously during the course of ischaemic heart disease due to occlusive coronary atherosclerosis.Special forms of coronary insufficiency may be associated with paroxysmal tachycardia, paroxysmal atrial fibrillation or flutter, severe haemorrhage or shock, asphyxia, hypertensive crises, ruptured aortic cusp, spirochaetal aortitis, severe anaemia, and several other conditions; but these are beyond the scope of this paper.I am concerned here entirely with coronary insufficiency as it occurs in ischaemic heart disease.My immediate purpose is to draw greater attention to this syndrome and its frequency, to redescribe its clinical features for the benefit of those who are still unfamiliar with it, to offer factual data concerning its natural course, and especially to record the results of anticoagulant therapy. MaterialThe analysis is based on a consecutive series of 150 cases seen over a period of about 10 years at the National Heart Hospital, at the Brompton Hospital, and in private practice.The diagnosis was made from the clinical history, negative physical signs, characteristic electrocardiogram, and absence of laboratory data denoting fresh infarction.In most cases attacks of angina were witnessed and in many an electrocardio- gram was also recorded when pain was present.The average age of these 150 patients was 56, and the male: female sex ratio was just under 3:1.The total duration of ischaemic heart disease when the patient was first seen averaged 3.7 years, previous cardiac infarction had occurred in 25%, and the electrocardio- gram provided conclusive proof of ischaemic heart disease in 87%.*Presented at the joint meeting of the British and Canadian Medical Associations in Edinburgh on July 21, 1959. PrevalenceThe true incidence of coronary insufficiency is difficult to determine.Some idea of its prevalence, however, may be gathered from the following data: