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?