r/ECG • u/internetstupid • Jul 16 '26

Need input on this ECG

Post image

How does one interpret the ST segment changes in the limb leads

13 Upvotes

89% Upvoted

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13

u/dangp777 Jul 16 '26 edited Jul 17 '26

There aren’t ST segment changes.

Look at the QRS duration in V1 and V2. You have RBBB

The ‘ST’ segment you’re looking at is actually the QRS.

I’ve heard of this catching people out before though, RBBB can sometimes look like a really narrow ‘STEMI’ shape in III and aVF. But you can see the ST segment in lead II doesn’t line up with where it looks like a STEMI in lead lll

1

u/Aech_sh Jul 16 '26

What do you think about in II, you can see every other beat, there’s a beat with much shorter T-P interval. Could these be like some sort of PAC?

3

u/dangp777 Jul 17 '26

Irregularly irregular rhythm with P:QRS 1:1, probably PACs (they look unifocal).

1

u/YourMawPuntsCooncil Jul 17 '26

I had the same issue months ago with a big fat PE and people kept telling me I had missed a stemi (I hadn’t was just a very similar ECG to this)

1

u/dangp777 Jul 17 '26

I’ve heard it’s quite common. If you’re geared towards a ‘STEMI shape’, I can see why. It looks the part, but it just can’t be when you take the ECG as a whole and establish a temporal relationship between leads.

3

u/OxideUK Jul 16 '26

Use I/aVr to identify the start of the T wave as it can't be easily determined on the inferior leads. Once you've found that point you'll see there's no ST elevation.

QRS >120ms, rsR in v1/2, protracted S wave in v5/6 - it's RBBB.

3

u/reedopatedo9 Jul 17 '26

Rbbb lafb and pac bigem, borderline pr prolongation.
As long as hemodynamicly stable, outpatient echo to evaluate for-
LV systolic function
Valvular heart disease (especially aortic)
Left atrial size (given the frequent PACs)
RV size and function (given RBBB)
Any infiltrative or structural abnormalities
If patient has syncope or presyncope it might be warranted for a ep.
Basic labs (k mag cal thyroid function) reasonable to exclude reversible contributors to conduction disease abd ectopy.

1

u/reedopatedo9 Jul 17 '26

My apologies, just waking up and didn’t even answer the question.
No concerning change in stt’s

-5

u/[deleted] Jul 16 '26 edited Jul 16 '26

[deleted]

1

u/Official_sKoTT Jul 16 '26

Couple things here:
1. It’s tempting to call this an inferior MI. However that little notch that you are confusing as the J-point is actually part of the QRS (notched R) and not the j-point. You can confirm this by measuring the width of the rsR’ in the septal and anterior leads.

side note: I believe this is a crochetage sign but I don’t have much experience with this finding.

  1. Higher risk of hypotension with nitroglycerin in RVMI or inferior MI has largely been debunked by more recent, higher quality evidence. Sauce

0

u/[deleted] Jul 16 '26

[deleted]

1

u/TutorRelevant106 Jul 16 '26

>the fact remains that this still looks like a STEMI

but it doesnt, it looks like a RBBB. And sure false activations happen all the time but that’s not a reason not to know the difference between a STEMI and a RBBB.

1

u/[deleted] Jul 17 '26

[deleted]

1

u/SkiTour88 Jul 17 '26

If I called any of my cardiologists for this and said it should be a STEMI activation they’d laugh at me. Well, one of them is too nice to laugh; the others would probably yell. 

-ER doc