CORONARY ARTERIAL DISEASEExogenous cholesterol metabolism in man has been studied by Biggs et al.(1) using tritium-labeled cholesterol. Ingested cholesterol was demon strated in an atherosclerotic aorta. Severe hypercholesterolemia was pro duced in rats by Page & Brown (2), intimal lipid infiltration occurring but atherosclerosis failed to develop. A sustained low blood cholesterol level has been obtained in man by Pollak (3) using sitosterol in oral dosage of 5 to 10 gm. per day. Paterson (4) consider � the precipitating factor in coronary artery occlusion of capillary rupture within the atherosclerotic plaques is more important than the degree of atherosclerosis.The early assessment of coronary artery insufficiency is of importance. Master et al. (5) give criteria of electrocardiographic changes following their exercise test which they consider to be more significant than the resting elec trocardiogram. Ischemic electrocardiographic changes comparable with those following exercise have been demonstrated by Contro et al. (6) after amyl nitrite inhalation, and the use of this as a simple functional test is suggested.Attention has been drawn by Papp & Smith (7) to the clinical entity of slight cardiac infarction. Cardiac pain, angina of effort, and a variable degree of shock and failure occur, but laboratory and clinical signs are minimal. The pathological lesions correspond to small areas of infarction which repre sent the acute stage of patchy myocardial sclerosis resulting from arterio sclerotic narrowing of the main coronary arteries and not from a local ar terial occlusion. Clinical recovery occurs in a high proportion of these cases. Q waves were absent in one-half of this group of patients and R-T changes were of the subacute type. Changes were found mainly in leads III R and aVFr, exercise being useful in demonstrating ischemia. Severe cases of posterior infarction had a mortality of 33 per cent; the prognosis in the moderate group was good. Elek et al. (8) have found the left back leads of value in diagnosis.High posterolateral infarction of the anatomical left surface of the heart has been the subject of an interesting study by Tulloch (9). Diagnostic signs of infarction are found in VL and lead 1. A predominant R wave is found in VI, with absence of a definite transitional zone in the precordial leads, a high upright T wave in two or more of these, and in the acute stage, S-T depression. Additional back leads are useful.Electrocardiographic and pathologic changes following infarction of the 1 The survey of literature pertaining to this review covers the period from July. 1952 to June, 1953. 51 Annu. Rev. Med. 1954.5:51-66. Downloaded from www.annualreviews.org Access provided by McGill University on 02/05/15. For personal use only. Quick links to online content Further ANNUAL REVIEWS