diffuse ST elevation dDx

Large acute MI

• Certain types of occlusion MI cause large territory infarction and ischemia, resulting in diffuse ST segment abnormalities

• Wrap-around LAD lesions with distal LAD occlusion has been thought to produce both anterior and inferior STE

• ​Occlusion MI typically has ± reciprocal ST-segment depression and clinical symptoms of ACS

• ECGs in acute occlusion MI typically have evolutionary changes, especially with treatment

Acute pericarditis

• Pericarditis is a challenging diagnosis that commonly mimics STEMI

• ​Causes concave STE without reciprocal ST-segment depression (except in aVR)

• Higher degree of STE compared to T wave amplitude (>25% of T wave height in V6)

• Less likely to change acutely compared to MI, changes are more gradual

• PR-segment depression may be present in both MI and pericarditis (not specific)

• Spodick’s sign (T-P downsloping) is suggestive but not specific to pericarditis

Early repolarization

• Causes widespread concave STE with notching or slurring at the J-point (fishhooks, J waves)

• Benign variant typically causes mostly precordial STE

• Malignant variant associated with arrhythmias and sudden cardiac death typically has inferolateral J wave notching or slurring at the end of the QRS

  • • J waves in multiple leads (esp. inferior) or with higher amplitudes (≥0.2 mV) are associated with higher risk

• ​No reciprocal ST-segment depression should be present (except in aVR)

• No PR-segment depression and prominent T waves are typical

• Modest degree of STE compared to T wave amplitude (<25% of T wave height in V6)

Ventricular aneurysm

• Concave or convex morphology STE seen more than 2 weeks after acute MI

• Usually has well formed Q waves

• Most commonly seen in precordial leads

• ECG may be similar to previous when compared and without dynamic ST changes

• No reciprocal ST-segment depression

Vasospasm

• Coronary vasospasm can cause diffuse STE that mimics STEMI

• ST changes evolve with symptoms ​and treatment

• Classically the STE seen is transient and not typically accompanied by reciprocal ST-segment depression