Friday, November 22, 2024

SSmith-DRAFT (KG- done) - 30 Examples of HATW (11-21.21-2024)-Draft- I_am_DONE


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MY Comment, by KEN GRAUER, MD (11/22/2024): 

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For optimally time-efficient identification of acute OMI in the absence of frank ST elevation — it's essential to get good at recognizing hyperacute T waves.
  • "A picture is worth 1,000 words". In today's post — Dr. Smith simply provides links to a series of such pictures for us to embed in our memory. Doing so literally enables those of us who embrace the OMI Paradigm the ability to recognize within seconds that a patient with new CP (Chest Pain) — and — one or more hyperacute T waves — needs prompt cath regardless of potential absence of STEMI criteria.

  • NOTE: It is guaranteed that rapid-fire review of these 30 examples will enhance your appreciation for how to recognize acute OMIs long before those of your colleagues who remain "stuck" on the old STEMI paradigm arrive at a similar conclusion (if they ever arrive there ...).

In Figure-1 is the ECG from the August 26, 2009 post in Dr. Smith's ECG Blog (this being one of the 10 Cases of Inferior HATWs that Dr. Smith links to — and the ECG for which he gives a preview of the HATW model that he and Dr. Meyers are working on). Below I note my "qualitative" assessment of this tracing (which QOH will be assisting us in the near future with her data-based analytical interpretation).
  • In this patient with new CP — Aren't the T waves highlighted by RED arrows disproportionately enlarged? ("fatter"-at-their-peak and wider-at-their-base than they should be, given size of the QRS in these leads).
  • Compare this relative disproportion of T waves in the inferior leads — to the proportions of QRS and T wave in lead V6 of this tracing. Any difference?
  • Confirmation that the extra "bulkiness" of these inferior lead T waves is "real" — is forthcoming from disproportionate reciprocal enlargement of the T wave inversion in lead aVL (that is almost large enough to "swallow up" the tiny QRS in lead aVL).
  • In Figure-1 — Since this patient is having new CP, this T wave disproportionality in 4 of the limb leads by definition represents hyperacute T waves that mandate prompt cath. With practice — the need for prompt cath should take your "knowing eyes" no more than seconds to recognize!

  • P.S.: The more abnormal leads and lead areas you can identify in a given ECG — the more solid the evidence of acute OMI becomes. Much more subtle (but still definitely present) in this 2009 case — is the lack of even slight ST elevation that we normally see in leads V2 and V3 (as well as some very subtle ST segment straightening in V2). While it would be difficult to be certain of this very subtle ECG finding by itself — in the context of definitely hyperacute T waves in leads II,III,aVF and aVL — I interpreted the lack of any ST elevation in V2,V3 as consistent with associated posterior OMI.

Figure-1: ECG from the August 26, 2009 post in Dr. Smith's ECG Blog.


Another Example
As a 2nd example from previous posts illustrating rapid recognition of hyperacute T waves — Consider the comparison picture in Figure-2 (taken from My Comment in the September 27, 2024 post written by Dr. Jesse McLaren).
  • The ST-T waves for leads V3,V4 on the left in Figure-2 (GREEN border leads) — are from a normal tracing. There is slight J-point ST elevation, with a gently upsloping ST segment that ends with a slender, upright T wave.
  • The ST-T waves for leads V3,V4 on the right in Figure-2 (RED and BLUE border leads) are from a patient with new CP.

QUESTION:
  • Why are the ST-T waves on the right in Figure-2 clearly hyperacute?

Figure-2: Comparison of normal vs hyperacute ST-T waves (from My Comment in the September 27, 2024 post in Dr. Smith's ECG Blog).


ANSWER to Figure-2:
  • In contrast to the normal ST-T wave appearance in the GREEN border leads — is the appearance of the ST-T waves from leads V3,V4 of the patient with new CP. Aren't these ST-T waves within the RED and BLUE rectangles clearly more "bulky", with a much wider T wave base than would be expected given modest QRS amplitude in these leads?
  • In this patient with new CP — these are hyperacute T waves suggestive of OMI until proven otherwise. Total Time needed to recognize these hyperacute T waves should be no more than seconds!
  • For details on this case — CLICK here — September 27, 2024 — 





SSmith - 11/24/2018 - My Comment on what is HATW?
ME TO FIX FONTS in 11/24/2018 post !!! 
https://hqmeded-ecg.blogspot.com/2018/11/large-t-waves-and-computer.html

August 26, 2009 - this is the ECG Steve shows 
(Note — I enlarged the figure on this 2009 post! )
http://hqmeded-ecg.blogspot.com/2009/08/inferior-hyperacute-t-waves.html


SSmith - 9/27/2024 - MY COMMENT - USE MY TEXT & FIGURE ! on HATW!
http://hqmeded-ecg.blogspot.com/2024/09/healthy-45-year-old-with-chest-pain.html

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MY Comment, by KEN GRAUER, MD (9/27/2024):

http://hqmeded-ecg.blogspot.com/2024/09/healthy-45-year-old-with-chest-pain.html

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Important question posed above by Dr. McLaren — namely, if working a busy shift in the ED and presented with the initial ECG in today's case (that I've reproduced in Figure-1) — Does this patient need to be seen immediately? 

To take Dr. McLaren's question to another level:
  • How long should it take you to know that this previously healthy 45-year old woman with new CP (Chest Pain) is having an acute OMI — at least, until you can prove otherwise?

Figure-1: I've labeled the initial ECG in today's case.


How Long Should It Take?
As per Dr. McLaren — OMI was correctly diagnosed in today's case. The point of my Comment — is that it literally took me less than 5 seconds to know that prompt cardiac cath was going to be needed. I based this on the following:
  • The History is Worrisome: This previously healthy 45-year old woman developed sudden, crushing retrosternal pain radiating to her arms, with associated lightheadedness. 
  • On learning this history, and then on seeing ECG #1 — my attention was immediately drawn to the ST-T wave in lead V3 (within the RED rectangle in Figure-1). We should instantly recognize that the shape of the ST-T wave in this lead is "off". That is — the T wave in V3 is overly large, "fatter"-at-its-peak and especially wider-at-its-base than it should be given relative size of the QRS in this lead. 
  • To assure myself that the abnormal appearance of the ST-T wave in lead V3 was "real" (and not the result of artifact or a repolarization change) — my "eye was next drawn to the ST-T wave in neighboring lead V4 (within the BLUE rectangle in Figure-1) — which showed a clearly disproportionate ST-T wave large enough to "swallow" the modest-sized R wave in this lead.

Conclusion: 
  • Given the history of severe, new-onset CP and the presence of hyperacute-looking T waves in leads V3 and V4 — I knew there was no way that this patient was not going to need full evaluation, and most likely prompt cath. 
  • Total TIME to Reach this Conclusion: Literally, less than 5 seconds.

Clearly, there are other findings of concern in this initial ECG (that I review below). But the point of my Comment is that Dr. Mastoras (who provided us with today's case) — was quickly able to recognize the hyperacute T waves, that in a patient with sudden, new and severe CP — mandate immediate further assessment.


A Picture is Worth 1,000 Words:
Why then in this patient with new CP — are the T waves in leads V3,V4 of Figure-1 hyperacute? The answer should be immediately apparent on looking at Figure-2:
  • The ST-T waves for leads V3,V4 on the left (GREEN border leads) — are from a normal tracing. There is slight J-point ST elevation, with a gently upsloping ST segment that ends with a slender, upright T wave.
  • In contrast to the normal ST-T wave appearance in the GREEN border leads — is the appearance of the ST-T waves from leads V3,V4 of today's initial ECG (taken from Figure-1). Aren't the ST-T waves within the RED and BLUE rectangles obviously more "bulky", with a much wider T wave base than would be expected given modest QRS amplitude in these leads? In a patient with worrisome CP — these are hyperacute T waves suggestive of OMI until proven otherwise.

Figure-2: Comparison of normal vs hyperacute ST-T waves.


Return to Figure-1: What are the Other ECG Changes?
Hyperacute T waves are "hypervoluminous". They are larger than what we expect given relative amplitude of the QRS complex in the lead(s) we are looking at.
  • Given the hyperacute changes we identified in leads V3 and V4 of Figure-1 — I like to look next at neighboring leads.
  • If any doubt remained about the abnormal appearance of the ST-T wave in lead V3 — it should be removed on seeing how flat the ST-T wave is in neighboring lead V2. There simply is no way the transition between the flat ST-T wave in V2 — to what we see within the RED rectangle in lead V3 — is going to be normal.
  • Given the hyperacute appearance in lead V4 — I thought the T waves in neighboring lateral leads V5,V6 were both "fatter"-at-their-peak than what is normally seen. And despite the tiny size of the QRS in lateral lead I — Isn't the T wave in lead I wider than you would expect? 
  • To Emphasize: I might not think the ST-T wave appearance in leads V5,V6 was abnormal if everything else on the tracing was normal. But in the context of the hyperacute neighboring leads V3,V4 — Doesn't the appearance of the ST-T waves in leads V5,V6 look like a tapering off of the same process?
  • Similarly — upright BLUE arrows in each of the inferior leads highlight "bulkier"-than-expected T waves.
  • Finally — lead aVL shows reciprocal T wave inversion to the inferior lead hyperacute T waves. This is subtle — but isn't the inverted T wave in lead aVL wider-than-expected given small amplitude of the QRS in this lead. 

BOTTOM Line: In today's patient (who presented with severe new-onset CP) — recognition of hyperacute T waves in leads V3,V4 can be made within seconds. As described above — increased scrutiny elsewhere on the tracing reveals ST-T wave abnormalities in virtually all remaining leads. As capably recognized by Dr. Mastoras — the need for prompt cath quickly became obvious.

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P.S.: Of interest — the previously healthy 45-year old woman in today's case was found to have SCAD (Spontaneous Coronary Artery Dissection) of the distal LAD, with resultant 95% narrowing of the involved area.
  • As per Dr. McLaren — the above demographic for today's patient is typical for a much higher-prevalence group for having SCAD as the cause of their acute event. Whereas SCAD is found in ~1-4% of all angiograms performed for ACS — this percentage increases to over 30% in middle-aged women. The risk of SCAD is even higher in pregnancy — accounting for over 40% of angiograms performed for ACS during the peripartum period.
  • Clinically — the importance of recognizing SCAD as the cause of ACS — is that the approach to management is different, in that a conservative approach (without PCI) is often favored in hemodynamically stable patients with good TIMI flow. (For more on this topic — See discussion in the October 24, 2019 and July 31, 2018 posts in Dr. Smith's ECG Blog).



 

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Figure-1: I've labeled the initial ECG in today's case.


SSmith - 11/24/2018 - My Comment on what is HATW?
ME TO FIX FONTS in 11/24/2018 post !!! 
https://hqmeded-ecg.blogspot.com/2018/11/large-t-waves-and-computer.html

August 26, 2009 - this is the ECG Steve shows 
(Note — I enlarged the figure on this 2009 post! )
http://hqmeded-ecg.blogspot.com/2009/08/inferior-hyperacute-t-waves.html


SSmith - 9/27/2024 - MY COMMENT - USE MY TEXT & FIGURE ! on HATW!
http://hqmeded-ecg.blogspot.com/2024/09/healthy-45-year-old-with-chest-pain.html

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MY Comment, by KEN GRAUER, MD (9/27/2024):

http://hqmeded-ecg.blogspot.com/2024/09/healthy-45-year-old-with-chest-pain.html

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Figure-1: The initial ECG in today's case. (To improve visualization — I've digitized the original ECG using PMcardio).



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SSmith DRAFT (11/19/2024):

Pendell and I are working on an objective, mathematical definition of hyperacute T-waves, and it will end up being some combination of: 

1) area under the curve relative to the QRS size

2) increased symmetry, as defined by time from T-wave onset to peak compared to time from T-wave peak to T-wave end.

3) some measurement of ST upward concavity (the less concave, the more likely to be HATW

4) The definitions will be different for different myocardial territories (for instance, HATW in inferior leads are different from those in anterior leads)

 

The Queen of Hearts is exceptional at recognizing hyperacute T-waves.

But you should be also.

The way to get good at it is to see a lot of them, and also see a lot of fake HATWs (mimics)

Here is a difficult pair of ECGs that demonstrate a difference:

One ECG is normal variant.  The other is Acute Anterior (LAD) OMI.  Which is which?








The top T-wave in V2 (A) has a smaller T-wave, but that is the hyperacute one!! Why?  1) it is much larger in proportion to the small QRS.

The bottom T-wave (B) is very large, but the QRS is much larger than in (A).  Notice that is has a slow upstroke to the peak, and a rapid downstroke. It is very assymetric!


Many examples of Hyperacute T-waves:




Here's the Case 2 from Inferior Hyperacute T-waves:



For a preview of our upcoming research, here is an image of the median beat of the ECG above, along with a HATW overlay that highlights T waves that meet one of our early definitions, requiring BOTH: increased T wave area / QRS amplitude, and increased T wave symmetry defined by position of the T wave peak along the whole T wave.


The early HATW model correctly identifies the HATWs in the inferior leads. The two measures in each lead are the 1) result of the T wave area (units mV x msec) / QRS amplitude (units mV), and 2) the T wave position from 0 to 100% of the T wave interval. It could be argued that V6 might also be hyperacute, and it is quite close to the thresholds for the values, but in our initial stages we are prioritizing specificity.



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