> [!Key Points]
> - Sgarbossa criteria
see also: [[Left Bundle Branch Block|LBBB]], [[ACS]]
Journal club paper for 2021 OMI article: [[OMI vs STEMI journal club.pdf]]
# LBBB or PPM with sgarbossa
> normal [[Left Bundle Branch Block|LBBB]]:
> - wide QRS
> - deep S wave in v1-v3
> - usually LAD
> - big R waves in lateral leads (I, aVL, V5-V6)
> - "appropriate discordance"
> [!tip]+ Sgarbossa criteria
> ==use in LBBB or PPM==
> **>95% specific for STEMI** (not very sensitive)
>
> **A - Concordant ST elevation >1 mm in any lead** (very specific)
> **B - Concordant ST depression >1 mm in V1, V2, or V3** (very specific) (*Barcillona allows for any lead, but not currently adopted* )
> **C - Discordant STE > 5mm** (NOT reliable; SMITH modification: When STE is >25% of the size of entire s wave, this is positive. Not currently fully adopted. NB the pic in C below is not Smith modification)
> ![[Pasted image 20230516174020.png]]
## Sgarbossa examples
![[Pasted image 20230516174859.png| 1. concordant STE in aVL, V5, concordant STD in III and aVF]]
![[Pasted image 20230516175612.png| 2. Concordant STD in V3 (also concordant STD in aVF, but this is not sgarbossa criteria)]]
![[Pasted image 20230516175925.png| 3. STD v3]]
![[Pasted image 20230516181023.png| 4. 38 yo with PPM. concordant STE in I and aVL]]
# RBBB
see also [[Right Bundle Branch Block|RBBB]]
- do not need any special criteria for evaluating STEMI in right bundle branch block
- ST elevation is NOT normal in RBBB
![[Pasted image 20230516181308.png|1. subtle ST elevation in V3, V4, V5. anterio-lateral STEMI]]
![[Pasted image 20230516181416.png| 2. RBBB with STE in V2-V4]]
# Posterior STEMI
- like inferior, also often from **RCA**
- 4-5% of all STEMIs are isolated posterior MIs
> [!tip] DDx for ST depression in anterioseptal leads (v1-v3)?
> - **anterioseptal ischemia**
> - **Posterior STEMI**
> - RBBB
> - hypokalemia
==ischemia vs posterior STEMI makes a big difference in management==
> [!danger] Posterior Myocardial Infarction ECG changes:
> - usually associated with [[ACS#inferior|Inferior MI]] due to RCA or circumflex occlusion
> - **Mirror image of septal MI in leads v1-v3:**
> - large R-waves (instead of Qs)... can be pathological (eg early r progression), happen a bit later in the progression of the infarct
> - STD (instead of STE)
> - upright T waves (instaed of inversions)
| |ST |T |later |vessel |
|---|---|---|---| ---|
|**Septal MI** | STE | Inverted Ts | Qs develop over hours| LAD|
| **posterior MI** | STD | upright Ts | Tall Rs develop over hours| RCA or LCx|
## Posterior STEMI examples
![[Pasted image 20230516183304.png|1. Isolated posterior STEMI. STD in V2 V3, very large R wave in V2 V3]]
![[Pasted image 20230516220308.png| 2. Inferior posterior STEMI. STE inferior, with deep T inv in V1-V5]]
## Posterior Leads
- if it is a posterior STEMI, posterior leads will show elevation;
- anterior ischemia will not show posterior elevation
![[Pasted image 20230516220941.png]]
![[Pasted image 20230516221033.png]]
### posterior leads example
![[Pasted image 20230516221236.png| STD in V2-V3, R wave not too big. Is this ischemia or posterior STEMI?]]
```mermaid
graph TD
START[ ]-- "posterior leads" --> STOP[ ]
style START fill:#FFFFFF00, stroke:#FFFFFF00;
style STOP fill:#FFFFFF00, stroke:#FFFFFF00;
```
![[Pasted image 20230516221308.png| posterior leads shows it is a STEMI!]]
# de Winter T-waves
- Concerning for acute proximal **LAD** occlusion
- > 1 mm of upsloping STD and tall symmetric T-waves, most commonly in the precordial leads. There may be 0.5-1 mm STE in aVR, but there should be no STE in the precordial leads.
- consider an anterior STEMI equivalent:
- aspirin 300mg, ticagrelor 180mg (unless hot CABG), heparin (unless time delay for angio → clexane)
- ==Patients with this ECG pattern and a presentation concerning for ACS warrant immediate revascularization==
- *Australian ACS guidelines* recommend coronary angiography with view to [PCI within 2 hours](x-devonthink-item://1C8D118F-382C-4964-A580-CF1530A06BF9?page=29)
> different from **hyperacute T waves**:
> - Hyperacute T-waves in ≥ 2 contiguous leads may be the first signs of a developing infarct, often preceding any STE.
> - Hyperacute T-waves appear broad based, often asymmetric with a more gradual upstroke than downstroke, and tall relative to the associated QRS complex
> - *note:* de Winter represents a small minority of subtle hyperacute T-waves that result from LAD occlusion
>
> different from **Wellen's syndrome:**
> - patients present *with* chest pain, making presentation even more acute
de Winter T waves:
![[Pasted image 20230516224023.png]]
no de Winter, but note **hyperacute T waves** in inferior leads and TWI in aVL:
![[Pasted image 20230516224241.png]]
another example of de Winter T waves from [Dr Smith ECG blog](https://hqmeded-ecg.blogspot.com/2025/01/another-must-know-ecg-and-why-its.html):
![[Pasted image 20250306105410.png]]
# Wellen's syndrome
- Medicall management is usually ineffective; 75% of patients have anterior AMI unless get PCI
- DON'T stress test them on treadmill
- Treat as ACS aspirin, ticagralor 180 mg, heparin 5000 (if time delay to angio → clexane), cardiology or retrieval
> [!Danger]+ Wellens' Syndrome ECG criteria
> highly predictive of a ==proximal LAD occlusion==
>
> - ECG pattern usually present when patient is pain-free for "syndrome"
> - However, if they are **symptomatic** with this pattern, it is **more worrying**
> - Troponins usually normal or not very high initially
>
> 2 patterns (representing different stages of the same progression):
> 1. **Biphasic T waves** (up then down) V2, V3 +/- V4
> ![[Pasted image 20230516225246.png]]
> 2. **Deep TWIs** (less subtle)
> ![[Pasted image 20230516225308.png]]
> According to the Dr. Smith crew, you **can** have inferior or lateral “Wellens” T waves, as they are a spectrum of [reperfusion](https://drsmithsecgblog.com/do-you-understand-these-t-wave/) phenomena (the classic “Wellens” above was just specifically described for LAD lesions.
## Wellens' Examples
![[Pasted image 20230516224734.png]]
![[Pasted image 20230516225909.png| biphasic v2, large inverted T waves v3, v4]]
![[Pasted image 20230516225958.png| also note inferior T inversions. CP at home, resolved by time of ECG]]
![[Pasted image 20230516230229.png]]
![[Pasted image 20230516230306.png| very subtle example! trops negative, got sent home, had anterior MI next day]]
![[Pasted image 20230516230429.png|diaphoretic 24 year old with lupus (risk factor for atherosclerosis), subtle biphasic in V3, V4]]
```mermaid
graph TD
START[ ]-- "4 days later" --> STOP[ ]
style START fill:#FFFFFF00, stroke:#FFFFFF00;
style STOP fill:#FFFFFF00, stroke:#FFFFFF00;
```
![[Pasted image 20230516230614.png| had been discharged with negative trops]]
# Others
## STE aVR with Diffuse STD
See [Amal Matu STE aVR](x-devonthink-item://371DA077-95EB-4C7C-85F6-E8D9026BFEE3?page=281)
- STE ≥ 1 mm in aVR or V1 with STD ≥ 1 mm in ≥ 6 leads can suggest left main coronary artery insufficiency, proximal LAD insufficiency, or triple vessel disease
- STD are most prominent in the inferior and lateral leads and thought to represent subendocardial ischemia
- This ECG pattern is not specific to LMCA/proximal LAD insufficiency and can be seen in other conditions (eg, pulmonary embolism, aortic dissection, LVH with strain pattern)
>In 2003, Barrabés and colleagues reported significant correlation between the level of ST-segment elevation in lead aVR and in-hospital mortality in patients with non-STEMI: for elevations of less than 0.5 mm, 0.5 to 1 mm, and 1 mm or more, the **mortality rates** were 1.3%, 8.6%, and 19.4%, respectively[^1]
![[Pasted image 20230516224707.png]]
## Terminal QRS distorsion
[^1]: Barrabés JA, Figueras J, Moure C, et al. Prognostic value of lead aVR in patients with a first non–ST-segment elevation acute myocardial infarction. Circulation. 2003;108(7):814-819