Management of Posterior Myocardial Infarction on ECG

ECG Recognition and Diagnosis

The European Society of Cardiology recommends that a posterior MI identified on ECG should be treated as a STEMI-equivalent requiring immediate reperfusion therapy with primary PCI as the preferred strategy, with fibrinolytic therapy as an alternative if PCI is not immediately available 1, 2, 3
Posterior MI presents with ST-segment depression in leads V1-V4, which represents reciprocal changes from the posterior wall injury, according to the American Heart Association 2, 3
The key distinguishing feature of posterior MI is horizontal ST-segment depression with upright precordial T-waves in ≥2 contiguous leads V1-V4, as stated by the American College of Cardiology 2, 3

The American Heart Association recommends ECG within 10 minutes of ED arrival with immediate evaluation by experienced physician, and decision for reperfusion therapy within 10 minutes of ECG diagnosis 4, 5, 6
Primary PCI is the preferred reperfusion strategy for posterior STEMI, as recommended by the European Society of Cardiology 1, 7
Fibrinolytic therapy is a Class II recommendation for posterior MI with symptom onset <12 hours when PCI is not immediately available, according to the American College of Cardiology 2, 3

The European Society of Cardiology recommends titrated intravenous opioids (morphine) for pain relief, but notes that morphine delays absorption and diminishes effects of oral antiplatelet agents 1, 8
Oxygen is indicated only if SaO2 <90% or PaO2 <60 mmHg, as recommended by the European Society of Cardiology 1, 8
Routine oxygen is NOT recommended when SaO2 ≥90% due to evidence suggesting hyperoxia may increase myocardial injury, according to the European Society of Cardiology 1, 8

The American College of Cardiology advises against withholding reperfusion therapy based solely on ST-depression if clinical suspicion for posterior MI exists 2, 3
Fibrinolytic therapy in undifferentiated ST-depression patients (without confirmed posterior MI) may increase mortality, as noted by the American Heart Association 2, 3

Primary PCI is the strategy of choice in resuscitated cardiac arrest patients with ST-elevation or posterior MI pattern, as recommended by the European Society of Cardiology 1, 7
Urgent angiography within 2 hours should be considered even in unresponsive survivors with high suspicion of ongoing infarction, according to the European Society of Cardiology 1, 7
Targeted temperature management (32-36°C for ≥24 hours) is indicated in unconscious post-arrest patients but should not delay PCI, as recommended by the European Society of Cardiology 1, 7