Broad, bulky T waves in V2-V4, big for the QRS in front of them, with a straightened ST and little or no ST elevation yet: the first minutes of an anterior occlusion.
In the first minutes of an occlusion the T waves swell before the ST lifts. Judge them against their own QRS, not against a number: a T wave as big as or bigger than the R in front of it, broad at the base, with a fat area under it and a straight run up from the J point instead of the normal gentle scoop. They sit in one territory, here V2-V4. The computer will usually call it normal, and it doesn't meet STEMI criteria yet. So repeat the 12-lead every 15-30 minutes while the pain lasts, and transmit it. Hyperkalemia's T is tall too, but narrow at the base and sharply pointed.
Each is a standard 12-lead: 2.5 seconds of each lead in four columns, with 10 seconds of lead II along the bottom, drawn to scale (25 mm a second, 10 mm a millivolt). The measurements are under each one.
T waves that are tall, narrow at the base and peaked, best seen in the chest leads. As potassium rises, the P wave flattens, the PR lengthens and the QRS widens.
Concave ST elevation in V2-V5 with a notched J point and tall, slightly lopsided T waves, no reciprocal depression, and a V6 ST under a quarter of its T wave's height. A normal variant, mostly in the young.
ST elevation across V1-V4, from an occluded left anterior descending artery.
Upsloping ST depression of more than 1 mm at the J point in the chest leads, running into tall, symmetric T waves, with no ST elevation there and slight ST elevation in aVR.
The ECG tool in the app gives you a new 12-lead every time and walks you through reading it: rate, QRS, axis, then where the ST is up and down. It's part of the Paramedic level, and you can try 5 ECGs a day free.
Try the 12-lead drill
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