Intermediate Coronary Syndrome

SEVERE or intractable chest pain, associated with sweating, vomiting, precipitate fall of arterial blood pressure, fever, and evidence of shock or collapse, clearly indicates a diagnosis of acute myocardial infaretion. In marked contrast is the entity of angina pectoris, with its paroxysms of chest pain after effort, typical radiation of pain into the arm, feeling of viselike constriction in the chest, and prompt response to rest and nitroglycerin. Between these two major forms of coronary heart disease is a wide and ill-defined zone, made up of many heterogeneous groups, but with the common denominator of pain, usually intermediate in severity and duration between that of angina pectoris and acute myoeardial infarction. Characterized typically by one or more bouts of prolonged chest pain, each lasting from 15 minutes to several hours, an equivocal or poor response to rest and nitrites, usually unrelated to physical effort, and, as a rule, unassociated with peripheral vascular collapse, congestive cardiac failure, pulmonary edema, sustained fever or auscultatory abnormalities, this intermediate form of coronary attack is seldom if ever accompanied by evidence of gross myocardial damage, such as high values of serum glutamic oxaloacetic transaminase and erythrocyte sedimentation rate, leukocytosis, and pathologic Q or QS patterns in the electrocardiogram. In the past, an attack of this type was indiscriminately classified either with angina pectoris or with acute myocardial infarction and designated by various terms including the following: atypical or anomalous angina; severe angina; angina of rest; angina decubi-