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.
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This ECG is from a man in his 40s who presented with intermittent chest tightness, shortness of breath and diaphoresis.
This ECG shows ST elevation in V1-6 and hyperacute T waves out of proportion to the size of the QRS. There is terminal QRS distortion in V3. The cause was an acute proximal LAD occlusion.
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.