Thursday, November 10, 2016

Biphasic T-waves in a Middle-Aged Male with Vomiting

One of our residents texted me this ECG and was worried about Wellens' waves.

A middle-aged male presented with vomiting.  Here was the initial ED ECG:

What do you think?

Here is my response:

Wellen's waves are always Up-Down T-waves, not Down-Up T-waves as here.  Down-Up T-waves in V2 and V3 have only two causes:

1) posterior MI with some reperfusion (reciprocal to Up-Down T-waves of the posterior wall, analogous to Wellens' of the posterior wall as recorded from the anterior wall).

2) Hypokalemia (in which case the upright component is really a U-wave).  In this case, V6 is pathognomonic: you can see a clear large U-wave following the T-wave.  It must be hypokalemia.  Notice also the very long QT, which is really a long QU-wave.

What is the Potassium?

The K was 2.0 mEq/L.

Here are classic Wellens Pattern A (biphasic) waves:
Notice they are biphasic Up-Down.

Clinical Course

The patient had all serial troponins below the level of detection.  Potassium was repleted.  Here is the ECG after normalization of K at 3.5 mEq/L:

Learning Points

1. Wellens' waves (Pattern A) are biphasic Up-Down.  (Pattern B is deep symmetric inversion)
2. Down-Up waves should make you think of reperfusing posterior MI or hypokalemia.
3. A very long QT (really a QU) should make you suspect hypokalemia.
4.  Look for clear U-waves in other leads.
5.  Finally, Wellens' syndrome is a SYNDROME that requires 1) typical anginal chest pain 2) Resolution of the chest pain 3) ECG recorded after resolution.

Here is an example of a Down-Up T-wave from Reperfusing Posterior MI.
It comes from this fascinating post:

Series of Prehospital ECGs Showing Reperfusion

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