Left ventricular aneurysm vs. acute anterior STEMI

Here’s the conclusion to 81 year old male CC: Palpitations.

Let’s take another look at the 12-lead ECG.

Some of you expressed concerns about the possibility of the ECG abnormality we sometimes refer to as left ventricular aneurysm (persistent ST-elevation after previous MI).

To put it another way, some of you think this STEMI looks “old”.

Stephen Smith, M.D. of Dr. Smith’s ECG Blog has a decision rule to help distinguish LVA from acute anterior STEMI by looking at the T/QRS ratio in leads V1-V4. T/QRS ratio best distinguishes ventricular aneurysm from anterior myocardial infarction. Am J of Emerg Med 2005 May; 23(3):279-287.

A high T/QRS ratio indicates acute STEMI. A low T/QRS ratio indicates LVA.

To come up with the T/QRS ratio you measure the amplitude of the T wave and divide by the depth of the S-wave.

If there is one lead in V1-V4 with a T/QRS ratio > 0.36, then STEMI is likely.

Or, if the sum of the T-waves in V1-V4 divided by the sum of the S-waves in V1-V4 > 0.22, then STEMI is likely.

Let’s look at the current case.

Lead V4 shows a T/QRS ratio of 0.38 which is suggestive of acute STEMI.

Let’s try the more complicated calculation (TV1+TV2+TV3+TV4 divided by SV1+SV2+SV3+SV4).

1+1.5+6+5 = 13.5

11+13+18+13 = 55

13.5/55 = 0.24 (T/QRS ratio)

Remember, the cut-off is 0.22 so this is very close but favors acute STEMI.

Finally, let’s consider another of Dr. Smith’s ECG interpretation tips: the rule of proportionality.

Lead V5 in this case shows a little bit of ST-elevation but the QRS complex is small. Let’s consider the ST/QRS ratio in this lead.

Here we use PowerPoint to “stretch” the QRS complex while preserving the ST/QRS ratio.

Looks pretty impressive to me!

Another finding that supports acute STEMI is the well formed R-waves in leads V3 and V4.

Typically LVA shows QS-complexes in leads V1-V4.

Diagnosis: Acute anterior STEMI (confirmed with angiography)

See also:

ECG mimics of acute STEM (left ventricular aneurysm)

Excessive discordance as a marker of acute STEMI in LBBB

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

Wolff-Parkinson-White (WPW) – STEMI Mimic

Left ventricular hypertrophy – Part I

78 year old male CC: Chest pain (Paced rhythm)

8 Comments

  • VinceD says:

    Very interesting case. I had read (maybe even in Dr. Smith’s book) that the T-waves of LVA tended to be lower than those of acute STEMI, but I had never seen a method with possible cut-offs of the proportions to aid with the diagnosis.

    I agree it definitely looked “new” as opposed to “old,” but being not just pain free, but symptom free, for 24 hours did a lot to confuse the picture. Had this patient walked into triage at my hospital (not PCI capable), I know it might have been very difficult to get him transferred for same-day PCI, let alone emergent revascularization as a STEMI. Do you have any information on how the call was handled (STEMI alert or not) or how rapidly the patient got to the cath lab? Thanks a ton for the great teaching you do on this site.

  • VinceD says:

    Also, there’s a typo in the sentence under the 12 lead at the top. You refer to it as hypertrophy rather than aneurysm.

  • Tom B says:

    Thank you for brining the error to my attention! It has been corrected.

  • Christopher says:

    I think the important part of this one was the PMD stating there were “changes”.

    “Could I see the prior ECG and could you make a copy for me.”

    Good case, although now I have to commit another formula to memory from Dr. Smith! Pretty soon I’m going to have to dust off my multivariate calculus books to read a 12-Lead.

  • Tom B says:

    Or carry a flash card! :)

  • Christopher says:

    Hah, that’s exactly what sits behind my accountability tag, 12-Lead flash cards! If I ever fall out they’re going to know I’m allergic to PCN and have too much free time on my hands.

  • Johan says:

    To VinceD :
    I think that it can not be considered as a direct alert case(symptom free for 24 hours), but I can not see any Q-waves so I think that acute PCI would be the case (“there is myocardium to save”).

  • ahmed says:

    very helpful case

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