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

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) ¹. These findings immediately prompt assessment for coronary reperfusion therapy ².
• Regional ST-segment depression or deep T wave inversion are suggestive of a non-ST-segment elevation myocardial infarction (NSTEMI) or unstable angina ¹.
• 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 ¹.
• It is important to note that a normal resting 12-lead ECG does not exclude an ACS ¹.
• 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 ¹. The 12-lead ECG is a crucial tool for diagnosing acute myocardial infarction in the emergency department (Miranda et al., 2018).
• ECG interpretation should be reviewed by a healthcare professional qualified to interpret them, while also taking into account automated interpretation ¹.