ABSTRACT
The term 'acute coronary syndrome' (ACS) refers to a range of acute myocardial ischaemic states. It encompasses unstable angina, non-ST segment elevation myocardial infarction (NSTEMI) and ST segment elevation myocardial infarction (STEMI). Rupture of an inflamed, thin-capped atherosclerotic plaque containing a lipid-rich necrotic core within an epicardial coronary artery, triggering platelet aggregation, thrombin generation and thrombus formation, has been identified as the common underlying event in ACS. The myocardium can tolerate and recover from around 15 minutes of total ischaemia without resultant myocyte death. There are two main methods of re-opening an acutely thrombosed coronary artery: intravenous administration of a thrombolytic agent or primary percutaneous coronary intervention (PCI). Primary PCI mechanically disrupts and compresses the occlusive athero-thrombus, rapidly restoring antegrade blood flow. The immediate information provided by coronary angiography is valuable in determining subsequent management. Nitroglycerin may be administered to relieve chest pain and is a useful preload vasodilator in patients with acute pulmonary oedema.
