What are the key features to identify in an ECG that suggest acute myo

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

To identify an acute myocardial infarction (MI) on an electrocardiogram (ECG), key features include:

Regional ST-segment elevation or presumed new left bundle branch block (LBBB) are consistent with an acute ST-segment elevation myocardial infarction (STEMI) . These findings immediately prompt assessment for coronary reperfusion therapy .
Regional ST-segment depression or deep T wave inversion are suggestive of a non-ST-segment elevation myocardial infarction (NSTEMI) or unstable angina .
Even in the absence of ST-segment changes, an increased suspicion of an acute coronary syndrome (ACS) should be maintained if there are other changes such as Q waves and T wave changes .
It is important to note that a normal resting 12-lead ECG does not exclude an ACS .
If the diagnosis of ACS is in doubt, healthcare professionals should consider taking serial resting 12-lead ECGs, reviewing previous ECGs, and recording additional ECG leads . The 12-lead ECG is a crucial tool for diagnosing acute myocardial infarction in the emergency department .
ECG interpretation should be reviewed by a healthcare professional qualified to interpret them, while also taking into account automated interpretation .

What are the key features to identify in an ECG that suggest acute myocardial infarction?