Investigation and reassessment of suspected acute coronary syndrome
THE CONTEXT
Initial and repeat electrocardiography and cardiac troponin measurements help assess suspected acute coronary syndrome and guide discharge decisions.
Initial assessment
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A 12-lead electrocardiogram (ECG) is mandatory and* is the most useful initial triage method, alongside measurement of cardiac troponin I or T.
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The ECG can be normal in acute coronary syndrome. ST segment elevation or depression and elevated troponin I or T support the diagnosis.
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Elevated troponin I or T indicates myocardial damage.
Repeat investigations
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If the diagnosis remains unclear, repeat ECG recordings; recordings obtained during pain are particularly useful.
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If baseline plasma troponin concentrations are normal, repeat measurements 2–3 hours after symptom onset or hospital admission to look for evolving myocardial injury.
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New ECG changes or an elevated plasma troponin concentration usually confirm acute coronary syndrome.
Discharge considerations
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Discharge is possible if pain settles without recurrence, there are no new ECG changes and troponin concentrations remain normal.
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Further investigations may still be indicated to look for coronary artery disease.