Reciprocal changes
Also calledreciprocal ST changes · mirror changes · reciprocal ST depression · reciprocal changes
Definition
ST-segment depression in leads whose positive pole points roughly opposite (about 180 degrees away) to leads showing acute ST elevation, appearing as a mirror image of the ST elevation recorded over the injured area. Its presence strongly supports acute infarction and helps distinguish STEMI from pericarditis or early repolarization, although its absence does not rule infarction out; reading the leads with ST depression together with those with ST elevation also sharpens localization of the affected region (for example, inferior STEMI in II, III and aVF with reciprocal ST depression in I and aVL).
Sources
- Morris F, Brady WJ. ABC of clinical electrocardiography: acute myocardial infarction, part I. BMJ. 2002;324(7341):831-834. doi.org/10.1136/bmj.324.7341.831
- Wagner GS, Macfarlane P, Wellens H, et al. AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part VI: acute ischemia/infarction. Circulation. 2009;119(10):e262-e270. doi.org/10.1161/CIRCULATIONAHA.108.191098
- Thygesen K, Alpert JS, Jaffe AS, et al. Fourth universal definition of myocardial infarction (2018). Circulation. 2018;138(20):e618-e651. doi.org/10.1161/CIR.0000000000000617
Last reviewed 2 October 2026. Every definition in the EKG Dictionary cites the guideline, consensus statement or original paper it comes from.