Myocardial injury
Also calledMyocardial current of injury · Current of injury
Definition
In current troponin-based usage, myocardial injury means a cardiac troponin value above the 99th-percentile upper reference limit; it is acute when the troponin rises and/or falls, and myocardial infarction is acute injury occurring with evidence of acute myocardial ischemia. On the ECG, the 'current of injury' is the ST-segment shift produced by injury currents, which flow because of voltage gradients across the boundary between ischemic and non-ischemic myocardium. Ischemia from acute coronary occlusion causes ST elevation in leads facing the affected region (with a mirror-image depression in opposite leads), while diffuse ST depression usually implies non-transmural (subendocardial) ischemia or injury.
Clinical noteThe ECG term 'current of injury' and the laboratory term 'myocardial injury' describe different things, and the ECG alone cannot tell myocardial injury from acute ischemia.
Sources
- 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
- 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
- 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
Last reviewed 2 October 2026. Every definition in the EKG Dictionary cites the guideline, consensus statement or original paper it comes from.