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


  1. Thank you for sharing this case,really helpful.
    Dr-Steve I have a question away from this topic,will be appreciated to get answer .
    Can intracranial hemorrhage or CVA Presented by alternating BBB?
    As a young male came with sudden loss of vision then deteriorating level of consciousness,ECG alternating RT,LT BBB,then deteriorating to VT then death.

    1. IC hemorrhage can cause a wide variety of ECG findings and I wouldn't be surprised if it led to the ones you describe.

  2. Intracrani hemorrhage can produce variety of ECG changes from the bradycardia and increase QT intervals, ST -T changes, abnormal rhythm, and abnormal conduction such as the BBB or alternating BBB block.

  3. Dr. Smith, from the electrocariographic point of view can we say that Wellens' waves are the evolution of an early ST elevation? Thanks in advance.

    1. Wellens' waves are reperfusion T-waves. When STEMI is reperfused, one of the first signs of reperfusion is the downward turn of the end of the T-wave. In Wellen's syndrome, there is absence of recording during chest pain, when one would have found STEMI. The artery reperfuses, the pain goes away, and the first recording you get is the terminal T-wave inversion. If you wait longer, you'll get pattern B (deep symmetric T inversion), as over time Pattern A evolves into Pattern B.

  4. Certainly, following epicard injury or even a subendocardial injury the repeperfusion is characterized by a resolution of the pain and the T waves are starting to inverte, intialy from their terminal end then middle and proximal end .

  5. Are down-up T-waves a finding that could be explain in precordial leads by the presence of RBBB?

    1. Sometimes in RBBB, in V1-V3 there is a negative T-wave that may end in a very small positive deflection, but I would not call it a down up t wave. And of course there is no RBBB here.

  6. Could down-up T waves be explained by an abnormal depolarisation (ie. RBBB)? Or should they always prompt further investigation.

  7. How to differentiate between the biphasic T wave and U waves ?

    1. Sometimes it is extremely difficult to distinguish between biphasic T waves and U waves. That said — Dr. Smith offers some suggestions in his Learning Points. So — a very long QT (really a QU) would be more likely with hypokalemia (in which case we are dealing with large U waves). Also — look at ALL 12 leads, because sometimes you will see clear U waves in some of the leads (but not in others). So clinical setting is key (Are you dealing with recent MI that now shows reperfusion — vs a clinical setting that predisposes to electrolyte disorders). Finally, the deflection in question will often “look like” either a biphasic T wave or a U wave. This is hard to explain (“A picture tells 1,000 words”) — but if we are dealing with a large U wave that subtly fuses into the terminal portion of the T wave — then that wave will be LONGER than if it simply represented the 2nd half of a biphasic T wave. So regarding this case and the 1st ECG — the clinical setting is “right” (ie, vomiting) — the QT (QU) is VERY long — and leads V5, V6 manifest a terminal positive deflection that just continues for far too long to simply be the 2nd half of a biphasic T wave — :)


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