Last updated 4/3/25
Is there an occluded coronary artery causing an acute myocardial infraction?
ECG #1
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- NO
- This is LBBB as evident by the wide QRS, dominant S wave in V1-V2 and monophasic R wave in I and V6. Use Modified-Sgarbossa Criteria to determine if this ECG is concerning for MI
- Applying the criteria reveals that this is ECG is not diagnostic of OMI.
- There are no concordant STE
- There are no concordant STD in V1-V3
- The STE excessively discordant STE
- Hyperacute T? in V4 - maybe repeat the ECG
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ECG #2
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- YES
- STE (II, III, avF) with reciprocal STD in I and VL suggest inferior MI
- STD in V2 suggest posterior involvement
- STE in V4-V6 suggest anterolateral involvement
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ECG #3
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- YES
- STE (II, II, avF) with reciprocal STD in avL suggets inferior MI
- STD in V2 suggests some posterior involvement
- Cath: RCA occlusion
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ECG #4
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- YES
- This is classic South Africa Flag Pattern with high lateral STE (I, avL) and inferior STD (III, avF) and V2 STE
- Cath: D1 occlusion
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ECG #5
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- NO
- T waves appear tall, but not in comparison to most of the QRS complexes so these less likely represent hyperacute T waves.
- The T waves do have symmetrical morphology, patient was found to be hyperkalemic to ≥ 6.0
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#ECG 6
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- No
- This is LVH with repolarization abnormality also known as “strain pattern”
- Note the overlapping QRS complexes with “discordant” ST deviations (depressions with tall R waves and elevations with deep S waves)
- Read more on the difficulties of interpreting LVH ECGs in our LVH OMI post.
- This patient ended up having a longstanding history of HTN and came to the ED for medication refill
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ECG #7
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- YES
- Another inferior-lateral MI with posterior involvement….are you getting tired of these?
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ECG #8
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- NO
- We can all agree this is a bizarre looking ECG
- The rate is slow (~48), the rhythm is regular, the QRS is wide with LBBB morphology, and there are no p waves making this an idioventricular rhythm
- V3 STD may meet Smith modified Sgarbossa criteria but this could be due to motion as the 2nd beat does not show the depression
- Subtle symmetrical T waves in V1-V4 + Bizarre looking idioventricular rhythm should have you thinking hyperkalemia
- This patient ended up having a K ≥7.0 and below is the post medical treatment ECG
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ECG #9
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- YES
- STE + hyperacute T waves in V2-V6 concerning for anterior-lateral MI
- STE in avL with reciprocal depression in aVL suggests high lateral involvement
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ECG #10
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- NO - but this is a concerning ECG, technically not OMI but could be Wellens (in the right clinical context).
- The TW inversions in the anterior leads are impressive, almost too impressive.
- Other differentials could be cerebral T waves, electrolyte derangement, or Takotsubo’s.
- TTE for this patient showed apical ballooning and cath was negative confirming Takostubo’s cardiomyopathy
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ECG #11
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- NO - this is a difficult one though.
- There is diffuse STE.
- There are qrs notching / J waves in most of the limb leads and the lateral precordial lead (V4-V6).
- There is no QRS terminal distortion in V2-V3 (there is a S wave in both).
- There are no reciprocal STD.
- This patient had positional chest pain after a post-viral syndrome. Serial troponins were negative and was ultimately diagnosed with pericarditis.
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ECG #12
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- NO
- This is LVH with strain pattern / repolarization abnormality
- LVH defined by peguero lo-presti criteria and also tall R wave in lead I (≥ 12mm)
- There are diffuse STD and (all in leads with R waves) with asymmetrical TW inversions consistent with strain pattern
- AVR STE with diffuse STD - remember your differential.
- Clinical context is important - This patient ended up having a history aortic stenosis and hypertension coming to the ED for extremity pain
ACO | Subendocardial Ischemia | Global Ischemia (non-coronary) | Repolarization Abnormalities |
Left main OMI | Multi-vessel CAD | Aortic syndrome | LVH with strain pattern |
pLAD OMI | Anemia, hemorrhage | LBBB, pacemaker | |
Hypoxia | Tachycardia / SVT | ||
Post cardiac arrest | Hypokalemia | ||
Massive PE | Brugada, TCA, acidemia, hyperK |
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ECG #13
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- YES - this is concerning for an anterior OMI
- STE in V1
- Hyperacute T waves in V2-V3 with terminal QRS distortion (read more here)
- STE + hyperacute T waves in V4-V5
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ECG #14
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- NO - but this demonstrates a short PR and delta waves (see limb leads and V4-V6) concerning for pre-excitation accessory pathway / WPW
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ECG #15
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- Yes
- This is another AVR STE with diffuse STD. Is this just LVH with strain pattern? No, notice the deep STD in the inferior leads that seem out of proportionally deep when compared to the small R wave they accompany. These could be reciprocal to the isolated STE in lead avL.
- There is also STE in avR and v1.
- This patient had chest pain and cath was activated which showed critical left main stenosis and severe triple vessel disease.
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Relevant Reading
This post is for education and not medical advice.