Assessment of acute chest pain of possible cardiac origin

Goodacre, 2002 National Institute for Health and Clinical Excellence (NICE), 2010 [updated 2016]

Patients presenting with acute chest pain require rapid evaluation.

Arrange immediate transport to hospital by ambulance for patients with suspected coronary ischaemia, undifferentiated chest pain that could be coronary ischaemia, or suspected serious cause of chest pain. Apart from an acute coronary syndrome, consider other serious causes of chest pain such as myocarditis, pericarditis, aortic dissection, spontaneous coronary artery dissection and pulmonary embolism.

Chest pain suggestive of an acute coronary syndrome is usually a crushing or heavy central chest pain that may radiate to the arms, neck, back and jaw. Pain may be interpreted as pressure, tightness or discomfort in any of these areas. Left arm pain is common, but bilateral or right arm pain are more specific. An acute coronary syndrome may also be associated with shortness of breath, nausea and sweating.

Other presentations of an acute coronary syndrome also commonly occur but may be less explicitly suggestive of an acute coronary syndrome. These presentations should not be ignored, particularly if there is high suspicion of an acute coronary syndrome. Consider symptoms such as burning pain, pain that increases with respiration, sharp pain (patients sometimes say ‘sharp’ when they mean ‘severe’ pain), and upper abdominal pain. Pain may also be absent (‘silent’ acute myocardial infarction); in particular, consider an acute coronary syndrome in patients with diabetes and older patients who have no pain but do have associated symptoms (eg shortness of breath, nausea, sweating), or diabetes. Avoid describing chest pain as ‘atypical’, because this can imply the pain is benign and does not need investigation for a cardiac causeWriting Committee Members, 2021.

Predictive value of clinical features of acute myocardial infarctions or acute coronary syndromes lists clinical features that may be associated with an acute coronary syndrome and their likelihood to predict an acute coronary event. The odds ratios in this table have been extracted from a single study and should be considered in the clinical context of the individual patient—they should not be used to either determine or rule out a diagnosis of an acute coronary syndrome.

Consider the possibility of coronary ischaemia in all cases where a clear alternative diagnosis is not evident.

All patients presenting with undifferentiated chest pain or symptoms that may be related to an acute coronary syndrome should have an early 12-lead electrocardiogram (ECG) if available. An ECG is a cost-effective investigation that can rapidly provide diagnostic information across a range of conditions causing chest pain, including ST elevation myocardial infarction (STEMI), non–ST elevation myocardial infarction (NSTEMI), arrhythmia, pulmonary embolism, aortic dissection, pericarditis and myocarditis. However, a normal ECG does not rule out coronary ischaemia or an acute myocardial infarction; continue to monitor the patient until a clear diagnosis is made.

If the patient has an old ECG that is readily available, comparison with the ECG performed on presentation can be helpful.

Clinical evaluation should include a comprehensive history and consideration of coronary risk factors and risk factors for other serious conditions. Examination should include vital signs, blood pressure taken from both arms, and examination of the cardiovascular, respiratory, abdominal and peripheral venous systems.

Prehospital advanced notification systems for hospital emergency departments and/or cardiac catheterisation laboratories should be used for patients with ST-segment elevation, a new left bundle branch block, or other changes consistent with acute coronary ischaemia that meet regional protocols.

An early test showing a low cardiac troponin concentration does not rule out coronary ischaemia, and an elevated troponin concentration can be due to myocardial injury rather than infarction (see Classification of coronary ischaemic syndromes)Aroney, 2016. The newer high-sensitivity troponin tests are changing reference ranges for the diagnosis of an acute coronary syndrome. Troponin concentration must be used together with a reliable clinical examination, ECG assessment, and imaging for a definitive assesment of undifferentiated chest pain and suspected acute coronary syndromePotter, 2022; use local hospital assessment protocols. Patients needing a troponin test should be referred immediately to hospital.

Patients evaluated in hospital for acute chest pain of possible cardiac origin should have cardiac monitoring and an intravenous line inserted; these should also be arranged for patients evaluated in the community or awaiting transport to hospital, if available.