When myocardial blood flow is acutely impaired (ischaemia), and often not provoked by exertion, a person will commonly suffer more prolonged pain; this is referred to as acute coronary syndrome (ACS). The underlying common pathophysiology of ACS involves the erosion or sudden rupture of an atherosclerotic plaque within the wall of a coronary artery. Exposure of the circulating blood to the cholesterol-rich material within the plaque stimulates blood clotting (thrombosis), which obstructs blood flow within the affected coronary artery. This coronary obstruction may be of short duration, and may not result in myocardial cell damage (necrosis), in which case the clinical syndrome is termed unstable angina. Unstable angina may result in reversible changes on the electrocardiogram (ECG) but does not cause a rise in troponin, a protein released by infarcting myocardial cells. Ischaemia which causes myocardial necrosis (infarction) will result in elevated troponin. When the ischaemia-causing infarction is either short-lived or affects only a small territory of myocardium the ECG will often show either no abnormality or subtle changes. This syndrome is termed non-ST-segment elevation myocardial infarction (NSTEMI). The diagnosis and immediate management of STEMI and the management of unstable angina and NSTEMI is addressed in other NICE Clinical Guidelines (CG95 and CG94). When the ischaemia-causing myocardial infarction (MI) is prolonged the affected person will usually experience more severe and sustained chest pain, often together with breathlessness, nausea and sweating. Symptoms can be atypical, particularly in women, the elderly, and people with diabetes. Not only will cardiac troponin be released, but the ECG will usually show ST-segment elevation, resulting in this more severe type of heart attack being termed ST-segment elevation myocardial infarction (STEMI). As detailed above, much is known about the management of STEMI and many advances have been made over the last 30 years. The recommendations in this guideline relate only to people with a diagnosis of STEMI. Chest pain of recent onset (NICE clinical guideline 95), covers the diagnosis of STEMI and should be read in conjunction with this guideline.
Copyright © 2013, National Clinical Guideline Centre.
- Guideline development group members
- Development of the guideline
- Guideline summary
- Time to reperfusion (delay between fibrinolysis and primary percutaneous coronary intervention)
- Facilitated primary percutaneous coronary intervention (fPPCI)
- Radial versus femoral arterial access for primary percutaneous coronary intervention
- Thrombus extraction during primary percutaneous coronary intervention
- Culprit versus complete revascularisation
- Cardiogenic shock
- People who remain unconscious after a cardiac arrest
- Hospital volumes of primary percutaneous coronary intervention
- Pre-hospital versus in-hospital fibrinolysis
- Use of antithrombin as an adjunct to fibrinolysis
- Rescue percutaneous coronary intervention
- Routine early angiography following fibrinolysis
- Adjunctive pharmacotherapy and associated NICE guidance
- 18 Acronyms and abbreviations
- 19 Glossary
- 20 Reference list
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Unstable Angina and NSTEMI: The Early Management of Unstable Angina and Non-ST-Segment-Elevation Myocardial Infarction.London: Royal College of Physicians (UK); 2010. Royal College of Physicians (UK). 2010. PMID: 21977549 Free Books & Documents. Review.
Management of acute coronary syndromes clinical guideline.S Afr Med J. 2001 Oct;91(10 Pt 2):879-95. S Afr Med J. 2001. PMID: 11757534
Diagnosis of unstable angina pectoris has declined markedly with the advent of more sensitive troponin assays.Am J Med. 2015 Aug;128(8):852-60. doi: 10.1016/j.amjmed.2015.01.044. Epub 2015 Mar 27. Am J Med. 2015. PMID: 25820165
API expert consensus document on management of ischemic heart disease.J Assoc Physicians India. 2006 Jun;54:469-80. J Assoc Physicians India. 2006. PMID: 16909697 Review.