What investigations would you want to perform on a patient with these symptoms?
ECG
Should be ordered as quickly as possible (within 10 mins of presentation) for any patient with a history of chest pain and suspected STEMI. Remember an ECG can be normal in some MI patients, for example if they have an occluded circumflex artery.
Cardiac Biomarkers
Troponin elevated 4-6 hours after cardiac muscle injury and remains elevated for 10 days. Therefore, it is of no use in the initial management of a STEMI.
Patients have a worse prognosis if they have a raised troponin compared to having normal troponin levels.
Result = elevated.
Glucose
Hyperglycemia is common in setting of acute MI, with or without patient history of diabetes.
Result = normal or elevated.
U&Es
Results are not cardio-specific, however is good practice to take a full complement of bloods to determines any electrolyte disturbances that may need to be managed.
Result = can be abnormal.
ECHO
New wall motion abnormality is part of the diagnostic criteria for MI, and is arguably more important than measuring a patients troponin as abnormal ECHO changes will be present immediately whereas troponin takes time to rise. An ECHO should also be performed after reperfusion therapy treatment for MI to look at the heart wall structure and valves for any potential complications of MI.
See the BMJ Best Practice website for more information on diagnostic tools for MI.