EMS Registry ReadyExample 1 · 12-lead · 10 seconds
- Rate
- 82/min
- Rhythm
- RegularSinus: upright in II, biphasic in V1, one before every QRS
- PR
- 0.13 s
- QRS
- 0.09 s, narrow
- Axis
- 43°, normal
- QTc
- 0.41 s
- ST up
- None
- ST down
- None
- T inverted
- V1, V2, V3
Wellens syndrome on a 12-lead ECG
Deep, symmetric T wave inversion in V2-V3 (type B), or T waves that go up then down there (type A), with little or no ST elevation, no Q waves and preserved R waves: a critical LAD lesion that has opened back up.
What to look for
The patient is usually pain-free when you record it, after chest pain that came and went. That's the trap. The LAD closed, then opened back up, and these T waves are its reperfusion signature. Type B is deep, symmetric T inversion in V2-V3 (sometimes V1-V6). Type A is a T that goes up, then down at the end, and it turns into type B over time. The ST stays under 1 mm, the R waves are still there and there are no Q waves, so it doesn't look like an infarct. Left alone, most of these patients go on to a large anterior MI within weeks. If the pain comes back, the T waves can flip upright again: that's the artery closing, and it's a STEMI equivalent.
Examples
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.
Example 2 · 12-lead · 10 seconds
- Rate
- 76/min
- Rhythm
- RegularSinus: upright in II, biphasic in V1, one before every QRS
- PR
- 0.15 s
- QRS
- 0.10 s, narrow
- Axis
- 55°, normal
- QTc
- 0.37 s
- ST up
- None
- ST down
- None
- T inverted
- V1, V2, V3
Don't confuse it with
- Hyperacute T waves (early anterior occlusion)
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.
- Anteroseptal STEMI
ST elevation across V1-V4, from an occluded left anterior descending artery.
- Normal 12-lead ECG
Sinus rhythm, a normal axis, normal intervals, R waves growing from V1 to V5, and no ST elevation or depression.
- De Winter T waves
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