Tuesday, June 6, 2023

A 50-something with acute chest pain

A 50-something presented with acute chest pain.

Here is her ED ECG.  It was texted to me while I was out and about.  

He wrote:
"Steve, what do you think about hyperacute T waves in this? 54-year-old female with CP. I initially interpreted as normal, but I am second-guessing myself, since she is hanging out in triage with me."

What do you think, Dear Reader?

Analysis: There is ST elevation in multiple leads.  There are tall T-waves in multiple leads.  So one might think this is an acute OMI with STE and hyperacute T-waves.   

However, the T-waves are not "fat" or "bulky".  they may be tall, but they have a VERY upwardly concave upstroke and a fast downstroke, so they are Asymmetric.  Thus, the "area under the curve" relative to the QRS is not large and so they just do not look hyperacute.

I immediately responded: Good question, but I think they are normal. 

One can use the LAD OMI vs. Normal Variant STE in V2-V4 formula (also known as anterior OMI vs. Early Repolarization)

You can use MDCalc here to calculate the formula.  The values would be:

Computerized QTc Bazett = 451 ms (I did it myself, as I could not see the computer calculation)

R wave amplitude in V4 = 9 mm

QRS in V2 = 9.5 mm

ST segment elevation 60 ms after the J point in lead V3 = 2.5 mm

Value = 22.3 

(This is a very high value and would be VERY positive for anterior OMI)

But the formula is not perfect.  And in this case, I would trust my subjective interpretation more than the formula.  That is a problem for others who need help.

And so I sent this ECG to the Queen of Hearts (PMcardio OMI), and below is the verdict.  The Queen of Hearts uses a Deep Convolutional Neural Network Trained on over 10,000 ECGs. 

You can subscribe for news and early access to the Queen of Hearts here: https://bit.ly/omi-queen-form

I posted this one because people want to see more cases that are NOT OMI, but are difficult ECGs.  To me, this is not a difficult ECG, but the fact that it was to someone is most important.

The vast majority (95%) of cases that are texted to me in real time are OMI Mimics (False positives).  The Queen of Hearts is very good at identifying them, because Pendell and I taught it to do so.

And it will only get better.

By the way, the patient ruled out for MI by troponins.


MY Comment, by KEN GRAUER, MD (6/6/2023):


Quick cases make for great practice in learning. Since I began working with Drs. Smith and Meyers — I’ve been amazed at their back-and-forth text dialog of interesting ECGs that they constantly exchange among themselves — usually with near instantaneous interpretations. The level of agreement between them in determining from a single ECG without history whether there is or is not acute coronary occlusion is uncanny! Once given the history — they don’t miss. Sharing their wisdom with others has been the goal of Dr. Smith’s ECG Blog for well over a decade.

MY Thoughts on today’s “quick-look ECG” are the following:
  • There is sinus arrhythmia. Intervals and axis are normal. No chamber enlargement.
  • Leads V1,V2 have been placed too high on the chest because: i) There is a single prominent negative P wave component in lead V1 (which is unusual in normal sinus rhythm — especially with no sign of left atrial abnormality in the limb leads)ii) There is an rSR’ in leads V1,V2 — which is unusual in normal tracings (I think the height and width of the terminal R’ in these leads is more than can be explained by incomplete RBBB)andiii) QRS morphology in similar between leads V1,V2 and lead aVR (See My Comment at the bottom of the page in the April 17, 2022 post of Dr. Smith’s ECG Blog for more on quick recognition of V1,V2 misplacement). Accurate placement of the lead V1 and V2 electrodes is critical for assessment of a possible anterior and/or posterior event — so IF you are truly concerned by this patient’s history, this ECG should be immediately repeated after ensuring correct lead placement!

  • Although T waves are clearly peaked in today’s tracing — these T waves look very similar in no less than 8/12 leads — without any reciprocal ST depression. This is highly unusual for acute OMI, which typically localizes (and which rarely shows identical-looking T waves in almost all leads).

  • BOTTOM LINE: It is OK if you are not as certain as Dr. Smith and QOH instantly were about today's tracing — namely, that today's ECG is not suggestive of acute OMI. Since this patient presented to the ED — You’ll soon have access to the initial troponin — AND — you can repeat the ECG in short order (ie, within no more than 10-to-20 minutes if chest pain persists) — to see if there is serial change. 
  • Realizing that the initial troponin can be normal despite OMI in at least 25% of cases — you can arm yourself with the knowledge that serial troponins and serial ECGs correlated to symptoms will almost always provide you with a definitive answer in a minimal period of time. But it is helpful to recognize that — Today’s ECG does not suggest an acute OMI.

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