Wednesday, October 12, 2011

ST elevation (Saddleback), is it STEMI?

This 56 year old male presented with atypical chest pain and left arm numbness off and on for one week, worse on the day of presentation:

There is saddleback type ST elevation in leads V2 and V3, and diffuse T-wave inversion.  But there is also very high voltage  especially in V4 (35mm, sorry it is cut off) and V5 (27 mm).  The QTc was 426 ms.

Answer is below:

This ECG was shown to me by a colleague, and I immediately said: "You thought it was a STEMI, but it is not."  He had, in fact, activated the cath lab, and the coronaries were clean and the patient ruled out.

Saddleback ST elevation, in my experience, is rarely due to STEMI.  I will not say it is never due to STEMI because I know of no research on this topic.  It is usually a form of early repolarization that also usually meets criteria for type II or III Brugada pattern (see this post).  I will post more on this topic later.  In this case, it may be related to the LVH or be simultaneous early repolarization and LVH.  The diffuse (both inferior and precordial) T-wave inversion is somewhat atypical of LVH. 

Echocardiography confirmed marked concentric LVH. 

In this case, you might want to try applying the early repol/anterior STEMI equation rule posted on the sidebar.  However, it is not validated in the presence of LVH).  You would get a value of 16.11, which is very low and argues strongly against LAD occlusion.


  1. Can we really say that diffuse T-wave inversion is "very typical" of LVH? Would we not expect discordant T-waves? The inferior T-waves look atypical to me because they are in the same direction as the majority of the QRS complex.

  2. I shouldn't say "very" atypical, but the T-wave inversion in inferior leads, in addtion to precordial leads, is simply atypical. Don't you think?

  3. Is the PR interval short? I eyeball it right at 0.12s.

  4. I'd call it BER secondary to LVH "strain pattern". Notice the slight notched J-point. Also noted LAE in V1. The T-waves in the left V leads are asymmetrical which is usually benign. The inferior T-waves are symmetrical which are pathological but could be BTWI

  5. I think you're right: it just barely meets normal.

  6. ------I'd call it BER secondary to LVH "strain pattern".

    --I haven't heard of BER being secondary to LVH; what do you mean?

    Notice the slight notched J-point.

    --Yes, BER.

    ------Also noted LAE in V1.

    --Yes, LVH.

    ------The T-waves in the left V leads are asymmetrical which is usually benign.

    --T-wave inversion from MI is frequently symmetrical; asymmetric inversion evolves to symmetric. See this post:

    What makes it likely not MI is the high voltage preceding it and the atypical ST saddleback ST elevation.

    The inferior T-waves are symmetrical which are pathological but could be BTWI.

    --BTWI (Benign T-wave inversion), as I have always understood it, and I will post on this some time, is in the precordial leads and is biphasic. Here is a great paper on it:

  7. Can you please comment on the w-shaped QRS in V2 ?

  8. Ahmad,

    that is what makes it a "saddleback" morphology.

    Steve Smith

  9. Dear Dr. Smith,
    Could these deep TWI in V4-V6 be due to apical HOCM.

    1. Amita,
      It could be, but the echocardiogram did not demonstrate any findings specific for HOCM.
      Steve Smith

  10. Does sadleback ecg meet criteria for an ICD ?

  11. maybe you're thinking of type 2 Brugada? Read this:

  12. What's about Q wave in v1, v2
    Here patient is with chest pain, not syncope so what's the imp of Brugada type 2 here
    generally it's Benign

    1. Q-waves can be seen in LVh.
      The importance is to illustrate that there are other conditions than STEMI which can produce STEMI look-alikes.


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