Hyperacute T wave
Also calledHyperacute T waves · Hyperacute T-wave changes
Definition
Broad-based, symmetric T waves, usually of increased amplitude and often with a slightly depressed ST takeoff, that are among the earliest ECG signs of acute ischemia from coronary occlusion. They appear soon after the occlusion, precede ST elevation, are short-lived (usually lasting about 5 to 30 minutes from the onset of infarction) and evolve into ST elevation; they are most evident in the anterior chest leads. Hyperkalemic T waves, by contrast, tend to be narrow and peaked with a sharp apex.
Sources
- Levis JT. ECG diagnosis: hyperacute T waves. Perm J. 2015;19(3):79. doi.org/10.7812/TPP/14-243
- 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
- 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.