Hyperacute T waves are tall, broad based and more symmetrical than normal. There is no absolute size that is too tall to be normal, as it depends on the size of the QRS. It has been suggested that a T:QRS ratio greater than 0.33 in V1-4 is abnormal. A T/R ratio has also been described. T waves in V4-6 should never be taller than the R wave. If in doubt, compare with a previous baseline ECG.
Hyperacute T waves can be the first sign of coronary occlusion. They localise to the affected artery distribution and can have reciprocal changes. They may also occur with Prinzmetal angina, or when the ST segments are on the way back down again after reperfusion.
See also: T and U waves
Can you add to the information on this page?
- Hampton, J and Hampton, J (2019) - The ECG Made Easy, 9th edn, Elsevier
- Thaler, MS (2018) - The Only EKG Book You'll Ever Need, 9th edn, Lippincott Williams and Wilkins
- (2015) - ECG Interpretation Made Incredibly Easy!, 6th edn, Lippincott Williams & Wilkins
- Houghton, AR and Gray, D (2014) - Making Sense of the ECG: A Hands-on Guide, 4th edn, Taylor and Francis
- Wagner, GS and Strauss, DG (2013) - Marriott's Practical Electrocardiography, 12th edn, LWW
- Osmosis (2019) - ECG Cardiac Infarction and Ischemia | Osmosis, (Accessed: 07/09/2019)
- Strong Medicine (2014) - Intro to EKG Interpretation - Myocardial Infarctions (Part 1 of 2), (Accessed: 05/09/2019)
- Miranda, DF et al. (2018) - New Insights Into the Use of the 12-Lead Electrocardiogram for Diagnosing Acute Myocardial Infarction in the Emergency Department, Canadian Journal of Cardiology vol 34(2):132-145 (Accessed: 24/08/2019)
This ECG is from a man in his 70s who presented with chest pain and nausea on a background of previous MI.
This ECG shows sinus rhythm with PVCs and subtle ST elevation in I, aVL and V2 and reciprocal ST depression in III and aVF. Angiogram was negative. The most likely cause was a brief LAD occlusion that spontaneously reperfused.
This ECG is from a man in his 40s who presented with chest pain since the previous evening, associated with vomiting and diaphoresis. He had recently stopped smoking.
This ECG shows subtle disproportionately tall T waves in V2-V3 and ST depression in V3-6 with slight ST elevation in V1. The cause was a 100% proximal LAD thrombotic occlusion.