See also: [[T inversion DDx]] > [!Key Points] > **pericarditis** > - try and avoid mis-diagnosing STEMI as pericarditis; if in doubt, assume STEMI > - pr depression is not specific for pericarditis > - don't bother with pr elevation in aVR > > **BER** > - DDx STEMI vs pericarditis vs BER > > **LVH** > - often mimics anterior wall STEMI > - When in doubt, get serial and old ECGs > - if pain, then discuss with cardiology # Causes of STE - [[ACS]] - global ischemia - LVH, WPW, etc - BER - myocarditis - pericarditis - vasospasm - ventricular aneurysm - LBBB/PPM - [[Pulmonary embolism ECG|pulmonary Embolism]] - [[Sodium channel blocker|sodium channel blocker toxicity]] (including [[TCA overdose]]) - post-cardioversion (stunning) - hypothermia - hypercalcemia - Takotsubo - "spiked helmet" sign - raised ICH **Cardiac causes of STE on ECG other than LBBB** - LVH -- ↑ R wave amplitude in leads I, aVL, and v4-v6. increased S wave depth in leads III, aVR, v1-v3. - takotsubo -- hard to distinguish from stemi - brugada - BER - pericarditis - aortic dissection **Non-cardiac causes** - elevated ICP - hypothermia -- [[Osborn waves]] - [[hyperkalemia]] # Pericarditis - rule out STEMI first - however, if you treat pericarditis with anticoagulation/thrombolytics, can cause **haemorrhagic tamponade** - if you cannot rule IN pericarditis, can do serial ECGs (don't expect any dynamic changes in pericarditis besides loss of pr depression), POCUS (eg RWMA and review for effusion), or admit cardiology ## rule out STEMI before ruling in pericarditis > [!danger]+ STEMI vs. pericardis > **step 1. rule out STEMI:** > 1. reciprocal STD changes in any leads except v1 or AVR > 2. STE in III > II > 3. horizontal or convex upward STE > 4. new Q waves > 5. RT or "checkmark" sign > > ==If any of the above are positive, then STEMI.== > > **step 2. rule in pericarditis:** > 1. friction rub > 2. PR depression in multiple leads (usually only in viral pericarditis; may be transient) > 3. ONLY allowed to have **concave upward** STE > 4. spodick's sign (downsloaping PR depression) ![[Pasted image 20230517001733.png| checkmark sign]] ![[Pasted image 20230517001757.png]] > when in doubt, get serial ECGs ## Examples 1. ![[Pasted image 20230517002417.png|STEMI. no reciprocal STD or STE in III >II, but note the horizontal STE in V3, V4. Therefore NOT pericarditis (pericarditis only allowed to give concave upwards)]] 2. ![[Pasted image 20230517002645.png| STEMI. obvious STE inferior, and reciprocal STD in aVL, so this is STEMI]] 3. ![[Pasted image 20230517002740.png|STEMI. STE v1-v6, aVF. no reciprocal STD, but horizontal upward STE, not concave, so not pericarditis]] 4. ![[Pasted image 20230517003429.png|Pericarditis. no reciprocal STD, no STE in III > II, no horizontal or convex upward STE, no infarction Q waves. PR depression/downsloping in v2, v3, v5. machine called this STEMI]] 5. ![[Pasted image 20230517003812.png|Pericarditis. No reciprocal STD. no STE in III, No convex/horizontal STE. significant precordial pr depression and down-sloping]] 6. ![[Pasted image 20230517004915.png| STEMI. young woman, positional/pleuritic CP. note reciprocal STD in III and aVF. ALSO note aVL has RT sign with abnormal QRS-T transition. positive trop, had LAD occlusion]] 7. ![[Pasted image 20230517010146.png|STEMI. sharp chest pain, subtle findings. however, note the baseline TP segment, so there is actually reciprocal STD in multiple leads, so diffuse ischemia, not pericarditis]] 1. ![[Pasted image 20230517010249.png|demonstrating the ST depression]] # Benign Early Repolarisation - exclude STEMI - The J point marks the end of the QRS complex and is often situated above the baseline, particularly in healthy young males - S wave= any deflection at the end of the R wave that dipped below the level of the PQ junction - J wave = any positive deflection (notching or slurring) above the level of the ST segment at the J point. - Distinct from the J point and classically seen in early repolarization and hypothermia. > [!danger] BER vs. STEMI > - like pericarditis, BER must **always have concave upward STE** (besides aVR and v1) > - BER never has STE in III > II > - BER often has a j wave in v2 or v3 (if it has a j wave it might not have an s wave) > - BER MUST have either an s wave or a j wave in v2 and v3 > - BER does **NOT** have terminal QRS distorsion > - *Terminal QRS distortion is defined as the absence of both an S wave and J wave in either lead V2 or V3* > - Terminal QRS distortion is highly specific to STEMI (left anterior descending artery occlusion. ![[Pasted image 20230517130133.png]] J wave ![[Pasted image 20230517131241.png]] Terminal QRS distorsion concerning for LAD STEMI | | STEMI | BER | |:----------------------|:----------------------------------------:|:-------------------------------------:| | **STE, STD** | frequent reciprocal STD | no reciprocal STD (except V1 and aVR) | | **ST segment morphology** | straight, horizontal, convex, or concave | concave upwards | | **if STE in II and III** | can be greater in either | STE in II &gt; III | | **evolving changes** | usually ST segments and Ts | no | ![[Pasted image 20230517125807.png| BER. STE in v6 < 1/4 height of T wave. AMI and pericarditis give much higher ratio of STE to T wave height]] # Left Ventricular Hypertrophy (LVH) - difficult to distinguish from STEMI - ECG criteria tend to be very specific, but not very sensitive - gold standard is ECHO - when people have longstanding LV strain, start to have ST segment changes > LV strain criteria > - (R in V5 or V6 + S in V1) >35 > - Max R + max S in precordial leads >45mm > - R in aVL >11mm > - R in I >15mm > - and other criteria > [!Danger]+ LVH with repolarisation abnormality > ST depression in any of I, aVL, v4-v6 +/- II and aVF > inverted Ts in same leads (tend to be asympetrical appearance) > STE in V1-V3 > QRS widening Hypothetical algorithm for anterior STEMI vs LVH: ```mermaid %%{ init: { 'flowchart': { 'curve': 'linear' } } }%% graph TD A["Are there ST elevations in V1-V3?"] -- yes --> C["is the ST elevation/RS wave ratio >25%"] A -- no --> B["use standard criteria"] C --- no ---> D["Not a STEMI"] C -- yes --> E[">=3 leads with STE"] E -- yes --> F["True STEMI"] E -- no --> G["V1-v3 t inversions present?"] G -- yes --> F E -- no ---> D ``` ^ From [Armstrong, Am J Cardiol 2012 ](bookends://sonnysoftware.com/ref/DL/151387), not validated though ## LVH vs. ischemia examples 1. ![[Pasted image 20230517192313.png| note symmetrical lateral T inversions, so this is ischemia]] 2. ![[Pasted image 20230517192401.png]]In contrast to (1), note the asymettrical T inversions in LVH with strain (incidental Mobitz 1 as well) 3. ![[Pasted image 20230517192552.png]] horizontal STD is always ischemia 4. # OSCE - [RMH STE ECG](x-devonthink-item://D91A5EBA-0166-4B64-B4AD-4D63E25C21D2)