Pendell-DRAFT- CP: Repol vs OMI? (5-10.1-2024)-I-am-DONE

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MY Comment, by KEN GRAUER, MD (5/10/2024):

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The "good news" about today's case — is that the treating clinicians promptly recognized ECG abnormalities in the initial tracing — documented abnormal Echo findings in support of suspected LAD OMI — and facilitated timely cardiac catheterization in which successful PCI led to a positive outcome.

• I'll add some thoughts about the first 2 tracings in today's case.
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Taking another look at the initial ECG (that I've reproduced in Figure-1) — this tracing is simply not easy to interpret. 

• There is a large amount of baseline artifact that complicates assessment of ECG #1. The underlying rhythm is sinus. That said — it took me a while to weed through the ever-present baseline undulations in this initial ECG, until I finally could recognize that a low-amplitude upright deflection (sinus P wave) does consistently appear before each of the 10 QRS complexes in the long lead II rhythm strip.
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• The distracting effect of this artifact is perhaps best appreciated by looking at the different ST-T wave appearance for the 2 QRS complexes that we see in leads V2 and V3. The principal diagnostic consideration, is whether this initial ECG is diagnostic of acute LAD OMI — for which these 2 anterior leads provide key input. But — Which ST-T wave is the "correct" one? (ie, the ST-T wave of beat #6 in leads V2,V3 — or — of beat #7 in these leads)?
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• That said, there does appear to be a "culprit" extremity responsible for much (most) of the artifact — which appears to be coming from the RA extremity, because baseline undulations are maximal in leads I, II and aVR — present but smaller in leads aVL and aVF — and absent in lead III  (See My Comment at the bottom of the page in the February 18, 2024 post in Dr. Smith's ECG Blog for review of how to quickly determine the "culprit" extremity). Therefore — It's worth a quick look at the patient to see if the RA electrode might be loose? — or — if there might be any other potentially "fixable" patient action that might account for the artifact.
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• NOTE: The filter setting for this initial ECG in today's case — was 0.05-to-40 Hz (lower right portion of Figure-1). This setting is consistent with monitor mode — which is the setting often used to help reduce artifact and baseline wander. However, monitor mode is less precise for assessment of ST-T wave morphology — than the 0.05-to-150 Hz filter setting recommended for diagnostic mode.
• Although clearly there are times when excessive movement artifact prevents use of the 0.05-to-150 Hz setting — it's good to appreciate the potential effect that filter settings may have, and best to first try the optimal 0.05-to-150 Hz setting when the focus is on ST-T wave analysis in a patient with chest pain (See My Comment in the January 13, 2024 post for more on filter settings).

ECG Findings in the Initial Tracing:

As per Drs. Folk, Engberg and Meyers — Even despite the artifact, ECG #1 is remarkable for hyperacute T waves in a number of chest leads — abnormal R wave progression — and a disproportionately large T wave in lead aVF.

• KEY Point: For however much technical issues may have complicated assessment of chest lead morphology — I thought the abnormal limb lead findings in ECG #1 were convincing enough to convey that an acute process was in progress because: i) There could be no doubt about the disproportionate hypervoluminous appearance of the T wave in lead aVF (compared to the tiny QRS complex in this lead); ii) Although not elevated — the ST segment coving in lead III was clearly abnormal, and further supported the hyperacuity seen in neighboring lead aVF; and, iii) The ST segment straightening with slight-but-real ST depression in lead aVL, in the context of this patient with new chest pain — satisfied the "magic" reciprocal ST-T wave appearance between leads III and aVL that so strongly suggests an OMI-in-progress.
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• Additional Point: Given the amount of artifact in ECG #1 — requesting an immediate repeat ECG might have clarified the ECG presentation.

Figure-1: The first 2 ECGs in today's case.

The Repeat ECG:

The 2nd ECG was recorded 25 minutes later.

• The artifact is gone! Although there is baseline wander — the clear and consistent QRST complexes now enable precise interpretation.
• In this patient with new CP (Chest Pain) — lead V3 immediately draws attention (within the RED rectangle in ECG #2) — because of its hyperacute T wave (clearly taller and "fatter"-at-its-peak and wider at its base than it should be — given small size of the QRS in this lead).
• In view of the abnormal T wave in lead V3 — the T wave in neighboring lead V4 is also hyperacute (more voluminous than it should be — within the BLUE rectangle in this lead).
• The 3rd definitely abnormal (disproportionate) T wave in ECG #2 — is in lead aVF (within the BLUE rectangle in this lead).

IMPRESSION:

Realizing the technical difficulty inherent in assessing artifact-laden ECG #1 — there appears to be dynamic change compared to repeat ECG #2 done 25 minutes later.

• The ST-T wave in lead V2 has normalized in ECG #2.
• Although difficult to appreciate (because of the artifact in ECG #1) what may represent "real" change in leads V3,V4 between the 2 tracings — the T waves in leads V5,V6 clearly look less acute in the repeat tracing.
• Subtle improvements are also noted in the limb leads of ECG #2. These include: i) Flattening of the ST segment in lead III in the repeat tracing; ii) Resolution of the slight ST depression in lead aVL; and, iii) Reduced relative size of the hyperacute T wave in lead aVF.
• 
  
• BOTTOM Line: In this high-prevalence for OMI patient with new CP — these 2 serial ECGs are diagnostic of acute LAD OMI, with need for prompt cath confirmed by dynamic ST-T wave changes between the 2 tracings. IF symptoms were decreased at the time (25 minutes later) when ECG #2 was obtained — the improvement we see in ECG findings between these 2 tracings would suggest spontaneous reperfusion of the "culprit" artery was beginning.

 

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MY Comment, by KEN GRAUER, MD (5/9/2024):

===================================

The "good news" about today's case — is that the treating clinicians promptly recognized ECG abnormalities in the initial tracing — documented abnormal Echo findings in support of suspected LAD OMI — and facilitated timely cardiac catheterization in which successful PCI led to a positive outcome.

• I'll add the following thoughts to the discussion by Drs. Folk, Engberg and Meyers.

Taking another look at the initial ECG in today's case (that I've reproduced in Figure-1) — this ECG is simply not easy to interpret. 

• There is a large amount of baseline artifact that complicates assessment. The underlying rhythm is sinus — but it took me some time to weed through the ever-present baseline undulations, until I finally could recognize that a low-amplitude upright deflection (sinus P wave) does consistently appear before each of the 10 QRS complexes in the long lead II rhythm strip.
• 
  
• The disruptive effect of this artifact is perhaps best appreciated by looking at the different ST-T wave appearance for the 2 QRS complexes that we see in leads V2 and V3. The principal diagnostic consideration, is whether this initial ECG is diagnostic of acute LAD OMI — for which these 2 anterior leads provide key input. But — Which ST-T wave is the "correct" one? (ie, the ST-T wave of beat #6 in leads V2,V3 — or — of beat #7 in these leads)?
• 
  
• That said, there does appear to be a "culprit extremity" responsible for much (most) of the artifact ( = the RA extremity) — because baseline undulations are maximal in leads I, II and aVR — present but less in leads aVL and aVF — and absent in lead III  (See My Comment at the bottom of the page in the February 18, 2024 post in Dr. Smith's ECG Blog for review of how to quickly determine the "culprit" extremity). Therefore — It's worth a quick look at the patient to see if the RA electrode might be loose? — or — if there might be any other potentially "fixable" patient action that might account for the artifact.
• 
  
• The filter setting for this initial ECG in today's case — was 0.05-to-40 Hz (lower right portion of Figure-1). This setting is consistent with monitor mode — which is the setting often used to help reduce artifact and baseline wander. However, monitor mode is less precise for assessment of ST-T wave morphology — than the 0.05-to-150 Hz filter setting recommended for diagnostic mode. 
• There are times when excessive movement artifact prevents use of the 0.05-to-150 Hz setting — but it's good to appreciate the potential effect of filter settings, and best to at least try first with the optimal 0.05-to-150 Hz setting when the focus is on ST-T wave analysis in a patient with chest pain (See My Comment in the January 13, 2024 post for more on filter settings).
• 
  
• Finally (as with assessment of any patient being evaluated for new chest pain) — serial ECGs provide tremendous insight, not only for the bottom line diagnosis (ie, acute OMI or no acute OMI) — but also with regard to whether the "culprit" vessel is likely to be open or closed at any given moment (which is why specific notation regarding the presence and relative severity of chest pain should be correlated with each ECG that is done).

ECG Findings in the Initial Tracing:

As per Drs. Folk and Engberg — ECG #1 is remarkable for hyperacute T waves in a number of chest leads — abnormal R wave progression — and a disproportionately large T wave in lead aVF.

• Whether the loss of R wave from V2-to-V3 was the result of anterior wall injury vs inaccurate lead placement — and how much of an effect artifact might be having on chest lead ST-T wave appearance — could probably be answered by repeating the ECG within 10-20 minutes of the 1st tracing.
• 
  
• KEY Point: For however much technical issues may have complicated assessment of chest lead morphology — I thought the abnormal limb lead ECG findings convincingly conveyed that an acute process was in progress because: i) There could be no doubt about the disproportionate hypervoluminous appearance of the T wave in lead aVF (compared to the tiny QRS complex in this lead); ii) Although not elevated — the ST segment coving in lead III was clearly abnormal, and further supported the hyperacuity seen in neighboring lead aVF; and, iii) The ST segment straightening with slight-but-real ST depression in lead aVL, in the context of this patient with new chest pain — satisfied the "magic" reciprocal ST-T wave appearance between leads III and aVL that so strongly suggests an OMI-in-progress.

Figure-1: The initial ECG in today's case. 

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The Initial ECG in Today's Case:

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NOTE: The filter setting was 0.05-to-40 Hz — or in monitor mode (which often helps to reduce artifact and baseline wander — but is less precise for assessment of ST-T wave morphology than the recommended 0.05-to-150 Hz filter setting for diagnostic mode.

SSmith - January 13, 2024 - My Comment on Filter Settings

https://hqmeded-ecg.blogspot.com/2024/01/orthostatic-hypotension-onset-after.html 

Credit to the team that quickly and accurately assessed the acute LAD OMI. That said — I would have tried to attain a greater degree of certainty as to the true appearance of ST-T waves by immediate repeat of the ECG (and additional serial tracings. 

LOTS of artifact (the rhythm is sinus — though hard to see in the long lead II

Perhaps best example is for beats #6 and 7 in the simultaneously-recorded critical leads V2 and V3. Which ST-T wave is the "correct one" (ie, the ST-T wave of beat #6 in leads V2,V3 — or of beat #7 in these leads)?

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SSmith-DRAFT-BLANK- XXX (4-28.1-2023)-BLANK DRAFT

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Figure-1: The initial ECG in today's case. (To improve visualization — I've digitized the original ECG using PMcardio).

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Pendell DRAFT as of 5-9.1-2024: 

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Chest Pain – Benign Early Repol or OMI? 

Written by: Destiny Folk, MD & Adam Engberg, MD

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PENDELL — The thrust of my comment (that I wrote on May 10) – is based on review of certain technical issues regarding the initial ECG. Below is the initial ECG that you had been using (and which I based my comments on). You'll note the filter setting (0.05 - 40 Hz) is written in the lower right corner — as well as showing 3 simultaneous long lead rhythm strips. 

• I feel my comment reviews a number of important points that are lost by the "new" initial 13:17 ECG that you show below.
• Could you Please GO BACK to the original ECG that had been in this Draft for the 13:17 tracing?
• I have added this initial tracing from 13:17 here — so would be GREAT if you could simply substitute this original ECG instead of the tracing you currently show. THANK YOU! (Ken — 5/13 @ 7:10pm EST).

THIS is the ORIGINAL 13:17 ECG that you had in the Draft. 

What do you think?

THANK YOU Pendell! — :) Ken

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A man in his early 60s with a past medical history of hypertension, type 2 diabetes, obesity, and hyperlipidemia presented to the emergency department for evaluation of chest pain. He reported substernal chest pressure with radiation to his left arm that started at work several hours prior to arrival and had somewhat improved since onset. He noted that his father died from a heart attack in his early 50s prompting his presentation to the emergency department. 



Here is the initial ECG at 13:17 with no prior ECG in the patient’s chart for comparison: 

The ECG shows hyperacute T waves in the anterolateral leads most prominent in V2-V5. The size of the T waves compared to the QRS in V2-V5 is particularly concerning for OMI. The T wave is too large for the QRS in aVF. There is also abnormal R wave progression when looking from lead V2 to V3. This ECG is concerning for LAD occlusion despite it not showing a STEMI. 

If you look at this and aren’t sure if this is normal variant ST Segment Elevation in V2-V4 (Early Repolarization) or a subtle LAD Coronary Occlusion, you can use Dr. Smith’s Simplified 4 Variable Formula. This formula considers the QTc (computer measurement), the R-wave amplitude, in mm, in lead V4, and the ST elevation is measured in 60 milliseconds after the J-point, relative to the PR segment, in millimeters. Lastly, the QRS amplitude in V2 (both the R- and S- waves) are measured. Using these measurements, the formula calculates a value. If that value is greater than 18.2, it is quite sensitive and specific for LAD occlusion. 

You can find the variables used to calculate the value on MD calc here: https://www.mdcalc.com/calc/10079/subtle-anterior-stemi-calculator-4-variable

Utilizing Dr. Smith’s Subtle Anterior STEMI Calculator (4-Variable), the value is greater than 18.2 which is concerning for LAD occlusion. 

The Queen of Hearts read this ECG as OMI – Low Confidence

 

The providers taking care of this patient were concerned regarding his clinical history and initial ECG, so they next performed a bedside cardiac ultrasound. POCUS showed Speckle tracking echocardiography (SPE) may provide another useful adjunct to further risk stratify chest pain patients anterolateral wall motion abnormality with hypokinesis most pronounced at the apex. 



Speckle Tracking Echocardiography may provide another useful adjunct. On the TEX Mindray machines, global longitudinal strain is defined as less than or equal to -16%. The Apical 4 Chamber best captured the significant wall motion abnormality to the apical anterior wall. The apical anterior and septal wall segments were identified with significant strain pattern as showed below in the bullseye diagrams:

The red circles correspond with the areas identified with significant cardiac strain. Emergent heart catheterization identified the culprit lesions causing this strain pattern: distal lesion 100% stenosed and a mid-LAD lesion 75% stenosed.  

Repeat ECG:

Emergent heart catheterization identified the culprit lesions causing this strain pattern: distal lesion 100% stenosed and a mid-LAD lesion 75% stenosed. 

Below is the ECG obtained after cath lab intervention:

This ECG is consistent with reperfusion given the T wave inversions shown in V2-V6 as indicated by the red arrows. 

The patient’s troponin peaked at 24,860. This patient had a smooth recovery and was discharged approximately 24 hours after his heart catheterization. 

Learning Points 

· The T waves should always be viewed in proportion to the QRS and if the T waves looks too big for the QRS, you should be concerned for OMI. 

· Use the Subtle Anterior STEMI Calculator (4-Variable) to differentiate normal variant ST elevation (benign early repolarization) from anterior STEMI. This formula can be found on MD calc at this link: https://www.mdcalc.com/calc/10079/subtle-anterior-stemi-calculator-4-variable 

· Speckle Tracking Echocardiography can be a useful adjunct in corroborating subtle EKG findings



· T wave inversions after a heart catheterization with intervention are consistent with reperfusion as shown below. T wave inversions may persist for days prior to the patient’s ECG returning to baseline. 




























Speckle Echo showing global longitudinal strain pronounced in the anterior/anteroseptal segments with A2 and PSLX views. Unfortunately, I couldn't get good tracking with the A3 view.










Troponin: 1709 --> 24,860 (was taken to cath prior to the 24K trop)





Wanted to follow up with you regarding the use of speckle echo (strain) in a patient found to have the following on cath report: 
Distal LAD lesion 100% stenosed 
Mid LAD 75% stenosed 


I couldn't find a prior EKG for patient; he had no previous cardiac hx. 



The screen captures (below) of the global longitudinal strain are consistent with the ST elevation in the anterior leads. 





I think Cardiology was more impressed with the first troponin of 1709.