The ECG is the only rapid, noninvasive diagnostic test that can identify coronary occlusion warranting reperfusion therapy at the bedside. The diagnostic paradigm of STEMI/NSTEMI is based on millimeter ST Elevation (STE) criteria as stated in the 4th Universal Definition of MI. It has identified candidates for emergent reperfusion for decades, but is limited by the low sensitivity and specificity of STE for acute coronary occlusion. A paradigm shift to Occlusion MI/Non-Occlusion MI (OMI/NOMI) has been proposed in response. Although the ECG is not embedded in the OMI/NOMI nomenclature as it is in STEMI/NSTEMI, it remains critical to the initial diagnosis of OMI. This review outlines six principles, dynamicity, acuteness, reciprocity, proportionality, totality, and surrogacy, that organize expert interpretation of the ischemic ECG and are essential to the electrocardiographic diagnosis of OMI. Each is drawn from established scholarship; the contribution here is their integration into one framework linked to coronary pathology.
