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Inferior Wall ST Elevation MI Review

An inferior wall myocardial infarction (IWMI, inferior MI or inferior STEMI) occurs when inferior myocardial tissue supplied by the right coronary artery (RCA), is injured due to thrombosis of that vessel. When an inferior myocardial infarction extends to posterior regions as well, an associated posterior wall myocardial infarction may occur. The ECG findings of an acute inferior myocardial infarction include:

  1. ST segment elevation in the inferior leads (II, III, and aVF)
  2. Reciprocal ST segment depression in the lateral and/or high lateral leads (I, aVL, V5 and V6)


Note: If the reciprocal ST depressions are not present, consider alternative causes of ST segment elevation such as pericarditis.

Inferior myocardial infarctions have multiple potential complications and can be fatal. See the review on ST elevation myocardial infarction for more detail on complications of an inferior myocardial infarction and a detailed discussion on treatment.

ECG Examples:

Related Links:

Topic Review: STEMI

Infarcts and Ischemia ECG Quiz


1. Surawicz B et al. ACC/AHA recommendations for the standardization and interpretation of the electrocardiogra. Circulation. 2009;119:e235-240.

2. Chou's Electrocardiography in Clinical Practice: Adult and Pediatric, 6e

By Steven Lome

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