Which initial investigations should be performed in a patient presenting with acute chest pain in primary care?

Perform a resting 12-lead ECG as soon as possible to identify any abnormalities suggestive of acute coronary syndrome (ACS) or other cardiac causes ¹.

Take a blood sample for high-sensitivity troponin I or T measurement to help diagnose myocardial infarction, ideally on arrival in hospital or as part of initial assessment ¹.

Carry out a physical examination to assess haemodynamic status, signs of complications such as pulmonary oedema, and signs of non-coronary causes like aortic dissection ¹.

Monitor oxygen saturation using pulse oximetry, and consider supplemental oxygen only if saturation is below 94% or if the patient has chronic respiratory conditions at risk of hypercapnic respiratory failure ¹.

Assess the characteristics of the pain, associated symptoms, and risk factors through detailed history-taking, which guides further investigations ¹.