Syndromes coronariens aigus sans sus-décalage du segment ST en médecine d'urgence

Abstract

Non ST segment elevation acute coronary syndromes (NSTE ACS) are a frequent cause of consultation in emergency departments, and hospitalisation in intensive care units. NSTE ACS are generally related to the rupture of an unstable atheromatous plaque located in a coronary artery and the development of a thrombus. The obstruction of the artery is usually incomplete. This broad pathophysiological context explains the great variability of both the clinical expression and the prognosis of NSTE ACS, and determines their treatment. The commonest initial presentation is a thoracic pain which has regressed at the time of consultation. Specific electrocardiographic signs are rare. Despite such relative benignity in the presentation, the risk of death or severe myocardial infarction is quite similar to that of patients with ST segment elevation ACS. Evaluating the level of risk for death and severe infarction in a patient is based on the rigorous collection of clinical and electrocardiographic signs and repeated measurement of troponin serum concentration. This stratification of the risk determines the management. For all patients, the treatment is based on aspirin, heparin or low molecular weight heparin, a beta-blocking agent and a statin. For patients at higher risk, particularly the diabetics and those with a measurable troponin, the treatment combines an anti GPIIb/IIIa agent and a coronarography aiming at a revascularisation. Secondary prevention begins together with the initial phase of management.