76 year old female CC: Chest pain – The case for this being an acute anterior STEMI

I find this case to be extremely interesting for a variety of reasons. (Click HERE to see the original post).

As many of you pointed out, the history and clinical presentation isn’t exactly screaming “Acute Coronary Syndrome!”

But then, as others have pointed out, the elderly often have atypical or vague symptoms.

Let’s look at the 12-lead ECG itself (I will post the serial ECGs to the original case study so you can see those, too).

First question, does it meet the ACC/AHA STEMI criteria (imperfect though it may be). I have to admit, when I first reviewed this case I didn’t see it, but the answer is, “Yes.”

Hyperacute T-wave are visible in several leads, the most noticeable of which are leads V4 and V5.

Here’s an important teaching point, courtesy of Dr. Smith from Dr. Smith’s ECG Blog in reference to this case.

“The T-wave is the best indicator of viable myocardium at risk.”

Is ST-elevation also present?

Some of you have been taught that 2 mm of ST-elevation is required in two contiguous precordial leads. That is only the case for leads V2 and V3. This is probably due to the fact that leads V2 and V3 often have deep S-waves.

In this case, lead V4 has about 2 mm of ST-elevation and lead V5 has 1 mm of ST-elevation.

Couldn’t this be benign early repolarization? In theory, yes, although BER is not particularly common in elderly female patients.

There’s also another way to tell. Look at the R-wave progression in leads V1-V4. It’s non-existent, which points away from benign early repolarization.

Do any other leads show ST-elevation?

As some of you mentioned in the comments, ST-elevation is present in the high lateral leads I and aVL. However, it’s less than 1 mm. So it’s not significant. Right?

Wrong.

It’s significant due to the low amplitude of the QRS complex! You have to consider proportionality.

To illustrate this point consider the following graphics that “stretch” leads I and aVL vertically while preserving the ST/QRS ratio.

This is the same image side-by-side but the image on the right has been “stretched” vertically. It’s a single cardiac cycle in lead I. It looks much worse when it’s stretched, doesn’t it? But the ST/QRS ratio is exactly the same!

Here’s another example of lead I.

Here’s lead aVL, normal on the top and “stretched” vertically on the bottom.

If only there were reciprocal changes to firm up the diagnosis!

You will notice a flattening of the ST-segment in leads III and aVF that by itself would not seem particularly significant in a 76 year old female with a history of emphysema. However, it’s all about context! Over and over again I have preached Tomas Garcia, MD’s admonition to “consider the company” that any ECG abnormality keeps.

A flattening of the ST-segments in the inferior leads when the anterior and high lateral leads are suspicious for acute STEMI should be considered reciprocal changes.

Now what do you think? Are you sold or do you still have doubts?

See also:

76 year old female CC: Chest pain

76 year old female CC: Chest pain – Conclusion (Tako-Tsubo Cardiomyopathy)

6 Comments

  • Medic999 says:

    The one thing that is still missing for me in this case is the patient presentation.
    If you are wanting an interpretation on the ECG alone, then I would obviously bow down to your knowledge over mine (after all you know I am one of your ‘young Padowans’

    I am intrigued to find out what the actual diagnosis for this patient was. If it was indeed a STEMI, as found by either blood results or PPCI, then it would indeed be a very atypical presentation of an MI.

    I have had many patients (as I am sure all of your readers have) that have fallen into one of two camps. Either the patient who looked incredibly poorly and ‘cardiac’ but had a normal ECG, or those who look absolutely fine whose ECG show an STEMI (but those at least were complaining of chest pain on examination)

    I would love to know what this patients quality of pain was like, the abruptness of onset and how quickly it resolved.

    Im sure I will be looking foolish when you tell us that she had a ‘big ol MI’, and I agree that the ECG is certainly suspicious, its just that the story doesn’t tally up, and maybe this is her ‘normal’ ECG.

    Whatever my thoughts though, as I said in my previous comment, it would still be sent off to the CCU dept anyway.

  • Tom B says:

    Mark –

    I expect to be able to provide a summary of the patient’s clinical course in the next week or so. I may even be able to provide a OPQRST (but right now I simply don’t know the answer).

    What I do know is that serial cardiac biomarkers were positive and the patient was admitted to the hospital.

    To me, other than the relevant features of the 12-lead ECG itself, the take-away lessons are:

    1.) Don’t walk a chest pain patient, even if they say they feel better.

    2.) All chest pain patients should be transported to the emergency department.

    3.) Abnormalities on the 12-lead ECG must be explained.

    We typically don’t have “old” ECGs or serial ECGs for comparison at the time of decision-making when a patient wants to know if they need to be transported.

    So don’t hedge! State confidently and unequivocally that yes, the patient needs to be seen in the emergency department.

    I’ve seen way too many paramedics who subtly talk patients out of going to the hospital.

    Fortunately, the EMS crew on this call was very conscientious. It could have easily been a refusal and “call us back if you need us.”

    Tom

  • Medic999 says:

    Tom,

    I 100% agree with you on the treatment and transport of the patient. The added side to the two options in my comment above is the same end disposition; if you look good but your ECG is of concern you are going, if you look terrible but your ECG is good you are still going!!

    No argument on that one my friend.

  • RM says:

    Tom,

    Totally agree with with I AVL, II, and III.

    I also agree that it isnt common to see BER in someone this age, and particularly female. But it also isn’t common to see someone this old wakeboarding either!

    Correct me if Im wrong but you expect to see similar T wave morphology in BER, and particularly in V2-V5 as seen in this case.

    I did see Dr. Smith’s old post on BER and by his criteria this is more likely STEMI than BER.

  • RM says:

    Oops slight correction in my last comment, I meant III and AVF, not II, and III.

  • audrey says:

    I would call it an anterior MI, especially with the reciprocal changes in III and aVF. In my service and with the hospitals anything greater than 1mm of change is considered ST elevation so even though one lead only has 1mm it’s still enough for us to call in and suggest activating the cath lab.

    My service doesn’t yet have the capability to send in 12 leads because they haven’t decided on which device to use so they rely on us in the field to determine whether or not the cath lab needs to be on stand by.

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