How to (Simply) Identify Old Myocardial Infarctions on an EKG: Master the Clues of Past Heart Attacks

Old myocardial infarctions (MIs) often fly under the radar—but recognizing them on a 12-lead EKG is essential for assessing long-term cardiac risk and guiding treatment decisions. This guide teaches you how to confidently detect prior MIs using two key diagnostic criteria, broken down in a simple, step-by-step format.


To enhance your learning, you'll receive a bonus video on naming the QRS complex—a fundamental skill for interpreting infarction patterns and other EKG findings. You’ll also get a visual cardiac anatomy chart to help you connect specific EKG changes to affected regions of the heart.


With expert pro tips included throughout, this guide will help you read with precision, avoid common mistakes, and improve your overall EKG interpretation confidence.

What You'll Learn:

  • The two key diagnostic criteria for identifying old myocardial infarctions
  • How to analyze infarction patterns accurately on a 12-lead EKG
  • The importance of QRS complex naming and how it supports accurate interpretation
  • How to use a cardiac anatomy chart to link EKG findings with specific heart regions
  • Pro tips to avoid common errors and sharpen your clinical precision
  • How to better assess a patient’s cardiac risk and treatment needs using EKG insights

This guide is suitable for:

Physicians, Advanced Practice Providers, Nurses. 

Ready to go deeper? The EKG 103 – Old Myocardial Infarctions course is a powerful next step. It expands on the guide with real-world examples, infarct localization strategies, and more advanced interpretation techniques to refine your skills even further.