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



12 comments:

  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.
    Regards

    ReplyDelete
    Replies
    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.

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  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.

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  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.

    ReplyDelete
    Replies
    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.

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  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 .

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

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    Replies
    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.

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

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

    ReplyDelete
    Replies
    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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