When the computer calls it Pericarditis…
Episode 128
February 10, 2014

PR depression is NOT specific for Pericarditis!

Pericarditis vs. STEMI

  • First, make sure you are not missing an acute MI by looking for factors strongly associated with STEMI. Ask yourself:

    • Is there reciprocal ST-segment depression in any leads (except for aVR and V1)? If yes, it’s a STEMI. If not,…

    • Is the ST-segment morphology convex or horizontal? If yes, it’s a STEMI. If not,…

    • Is the STE in lead III> the STE in lead II? If yes, it’s a STEMI.

    • Are there new Q waves? (Need old ECG) If yes, it’s likely a STEMI.

    • Is there a QR-T or check mark sign? If yes, it’s likely a STEMI.

  • If the answer to all those questions is NO, then you can consider the possibility of it being pericarditis.

    • Is there pronounced PR-segment depression in all leads? If so, it’s possibly pericarditis.

    • Is there a pericardial friction rub? If so, it’s possibly pericarditis​.

Do you remember what the check mark sign is? If not check out this previous episode and the links on that page for more cases. 

When the computer calls it Pericarditis…
Episode 128
February 10, 2014

PR depression is NOT specific for Pericarditis!

Pericarditis vs. STEMI

  • First, make sure you are not missing an acute MI by looking for factors strongly associated with STEMI. Ask yourself:

    • Is there reciprocal ST-segment depression in any leads (except for aVR and V1)? If yes, it’s a STEMI. If not,…

    • Is the ST-segment morphology convex or horizontal? If yes, it’s a STEMI. If not,…

    • Is the STE in lead III> the STE in lead II? If yes, it’s a STEMI.

    • Are there new Q waves? (Need old ECG) If yes, it’s likely a STEMI.

    • Is there a QR-T or check mark sign? If yes, it’s likely a STEMI.

  • If the answer to all those questions is NO, then you can consider the possibility of it being pericarditis.

    • Is there pronounced PR-segment depression in all leads? If so, it’s possibly pericarditis.

    • Is there a pericardial friction rub? If so, it’s possibly pericarditis​.

Do you remember what the check mark sign is? If not check out this previous episode and the links on that page for more cases. 

The myth of Medusa & stone heart revealed…
Episode 127
February 3, 2014
Bizarre rhythm? Think about hyperkalemia!
 Knowing all the variations of ECG findings in hyperkalemia saves lives.
 
ECG finding associated with hyperkalemia:
  • Peaked T-waves
  • Widening of the QRS
  • Prolonged PR
  • Flattening and eventual loss for p-waves
  • Advanced AV Blocks and sinus pauses
  • Pseudo ACS, new BBB’s, ST-segment changes
  • Sine wave morphology
In digoxin-intoxicated humans, IV calcium does not seem to cause malignant dysrhythmias or increase mortality. Evidence does not support the historical belief that calcium administration is contraindicated in digoxin-toxic patients. 

 

Reference

Levine M, Nikkanen H, Pallin DJ. The Effects of Intravenous Calcium in Patients with Digoxin Toxicity. J Emerg Med. 2011;40(1):41–46. Pubmed Link

The myth of Medusa & stone heart revealed…
Episode 127
February 3, 2014
Bizarre rhythm? Think about hyperkalemia!
 Knowing all the variations of ECG findings in hyperkalemia saves lives.
 
ECG finding associated with hyperkalemia:
  • Peaked T-waves
  • Widening of the QRS
  • Prolonged PR
  • Flattening and eventual loss for p-waves
  • Advanced AV Blocks and sinus pauses
  • Pseudo ACS, new BBB’s, ST-segment changes
  • Sine wave morphology
In digoxin-intoxicated humans, IV calcium does not seem to cause malignant dysrhythmias or increase mortality. Evidence does not support the historical belief that calcium administration is contraindicated in digoxin-toxic patients. 

Search the site to watch more videos on the bizarre ECG manifestations of #hyperkalemia
 

Reference

Levine M, Nikkanen H, Pallin DJ. The Effects of Intravenous Calcium in Patients with Digoxin Toxicity. J Emerg Med. 2011;40(1):41–46. Pubmed Link

How many ECGs does it take to save a life?
Episode 126
How many ECGs does it take to save a life?
Episode 126
January 27, 2014

When in doubt, get serial ECGs!

  • Reciprocal changes can precede ST-elevation (STE) in MI

  • New TWI in aVL can be the first sign of an Inferior STEMI

  • Get serial ECGs​ in patients with persistant or changing chest pain

  • Check out more cases with #Early reciprocal changes


March 28-31st
Click banner to learn about this awesome upcoming conference
How to avoid misdiagnosis of Mobitz I
Episode 125
January 20, 2014
 

Why does this simple rhythm get misdiagnosed so much?

Don’t trust the computer’s ECG interpretation!

  • Atrial fibrillation should produce an IRREGULARLY irregular ventricular response

  • Always scrutinize lead V1 (closest to the sinus node) for P-waves (atrial activity)

  • Pay close attention to the PR-interval to avoid missing AV blocks

  • If the rhythm is REGULARLY irregular with grouped or “clumped beats” consider:

  1. Premature atrial contractions (PACs)

  2. 2nd degree AV blocks (Mobitz I and Mobitz II)


Want more cases? To review previous episodes & prove your ECG machine wrong, check out #ClumpedBeats

How to avoid misdiagnosis of Mobitz I
Episode 125
January 20, 2014
 

Why does this simple rhythm get misdiagnosed so much?

Don’t trust the computer’s ECG interpretation!

  • Atrial fibrillation should produce an IRREGULARLY irregular ventricular response

  • Always scrutinize lead V1 (closest to the sinus node) for P-waves (atrial activity)

  • Pay close attention to the PR-interval to avoid missing AV blocks

  • If the rhythm is REGULARLY irregular with grouped or “clumped beats” consider:

  1. Premature atrial contractions (PACs)

  2. 2nd degree AV blocks (Mobitz I and Mobitz II)


Want more cases? To review previous episodes & prove your ECG machine wrong, check out #ClumpedBeats

Pacemakers & Acidosis
Episode 124
January 13, 2014

Can pacemakers prevent syphilis? Find out here! 


ECG findings in Hyperkalemia
  • Peaked T-waves
  • Widening of the QRS
  • Prolonged PR
  • Flattening and eventual loss for p-waves
  • Advanced AV Blocks and sinus pauses
  • Pseudo ACS, new BBB’s, ST-segment changes
  • Sine wave morphology
Really wide QRS? Always consider Hyperkalemia/Acidosis & Overdose
Don’t be misled by pacers,which may not work well in acidosis!
Pacemakers & Acidosis
Episode 124
January 13, 2014

Can pacemakers prevent syphilis? Find out here! 


ECG findings in Hyperkalemia
  • Peaked T-waves
  • Widening of the QRS
  • Prolonged PR
  • Flattening and eventual loss for p-waves
  • Advanced AV Blocks and sinus pauses
  • Pseudo ACS, new BBB’s, ST-segment changes
  • Sine wave morphology
Really wide QRS? Always consider Hyperkalemia/Acidosis & Overdose
Don’t be misled by pacers,which may not work well in acidosis!

Knowing this stuff saves lives! For more practice check out…#Hyperkalemia
Himalayan T waves
Episode 123
Himalayan T waves
Episode 123
January 6, 2014

You’ll never look at the mountains the same way again


Himalayan T waves 

  • Giant broad and spiked T waves 
  • Associated with syncope & seizures (due to torsades)
  • Think of congital long QT (Jervell and Lange-Nielsen syndrome)
  • Can also be seen in severe hypokalemia 

Check out this link for a case of congenital long QT with Himalayan T waves and a QTc of 900ms! ​

Also, search these tags for more practice with #T-waves & #Prolonged-QT

Low Voltage QRS Differential
Episode 122
December 30, 2013

Electrocardiographic voltagemia. What’s the significance?

Low Voltage Definition
  • QRS amplitudes in limb leads all < 5 mm or in all chest leads < 10mm (specific definition)
  • QRS amplitudes in I+II+III < 15 mm or V1+V2+V3 < 30 mm (sensitive definition)
Low Voltage QRS Differential
  • “Low Power”
    • Myxedema (severe hypothyroidism)
    • Infiltrative diseases (Amyloid, Sarcoid)
    • End stage cardiomyopathy
  • Conduction blockage
    • Fluid/Effusion (pericardial or pleural)
    • Fat (obesity)
    • Air (COPD)
Don’t rely only on electrical alternans to diagnose pericardial effusions.
Low voltage + Tachycardia = Pericardial effusion until proven otherwise!
Low Voltage QRS Differential
Episode 122
December 30, 2013

Electrocardiographic voltagemia. What’s the significance?

Low Voltage Definition
  • QRS amplitudes in limb leads all < 5 mm or in all chest leads < 10mm (specific definition)
  • QRS amplitudes in I+II+III < 15 mm or V1+V2+V3 < 30 mm (sensitive definition)
Low Voltage QRS Differential
  • “Low Power”
    • Myxedema (severe hypothyroidism)
    • Infiltrative diseases (Amyloid, Sarcoid)
    • End stage cardiomyopathy
  • Conduction blockage
    • Fluid/Effusion (pericardial or pleural)
    • Fat (obesity)
    • Air (COPD)
Don’t rely only on electrical alternans to diagnose pericardial effusions.
Low voltage + Tachycardia = Pericardial effusion until proven otherwise!
T-wave Inversions & ST-Elevation
Episode 120
December 16, 2013

Are you an arrogant schmuck? Find out in 20 minutes!


New T-wave inversion in aVL may be a reciprocal change!

  • Reciprocal changes can precede ST-elevation (STE) in MI
  • New TWI in aVL can be the first sign of an inferior STEMI
  • When in doubt, get serial ECGs
  • STE is complicated
  • Use the J-point, 2 contiguous leads
    • Women: 1.5 mm in V2-V3 and 1 mm in all other leads
    • Men < 40yo: 2.5 mm in V2-V3
    • Men > 40yo: 2 mm in V2-V3 and 1 mm in all other leads
  • ​Pay attention to ST and T-wave morphology
  • Consult cardiology for joint decision-making

Search #Early reciprocal changes to check out similar cases


References

Wagner GS, Macfarlane P, Wellens H, et al. AHA/ACCF/HRS Recommendations for the Standardization and Interpretation of the Electrocardiogram. J Am Coll Cardiol. 2009;53(11):1003–1011. Pubmed Link

Thygesen K, Alpert JS, Jaffe AS, et al. Third Universal Definition of Myocardial Infarction. J Am Coll Cardiol. 2012;60(16):1581–1598. Pubmed Link

O’Gara PT, Kushner FG, Ascheim DD, et al. 2013 ACCF/AHA Guideline for the Management of ST-Elevation Myocardial Infarction. J Am Coll Cardiol. 2013;61(4):e78–e140. Pubmed Link
 
T-wave Inversions & ST-Elevation
Episode 120
December 16, 2013

Are you an arrogant schmuck? Find out in 20 minutes!


New T-wave inversion in aVL may be a reciprocal change!

  • Reciprocal changes can precede ST-elevation (STE) in MI
  • New TWI in aVL can be the first sign of an inferior STEMI
  • When in doubt, get serial ECGs
  • STE is complicated
  • Use the J-point, 2 contiguous leads
    • Women: 1.5 mm in V2-V3 and 1 mm in all other leads
    • Men < 40yo: 2.5 mm in V2-V3
    • Men > 40yo: 2 mm in V2-V3 and 1 mm in all other leads
  • ​Pay attention to ST and T-wave morphology
  • Consult cardiology for joint decision-making

Search #Early reciprocal changes to check out similar cases


References

Wagner GS, Macfarlane P, Wellens H, et al. AHA/ACCF/HRS Recommendations for the Standardization and Interpretation of the Electrocardiogram. J Am Coll Cardiol. 2009;53(11):1003–1011. Pubmed Link

Thygesen K, Alpert JS, Jaffe AS, et al. Third Universal Definition of Myocardial Infarction. J Am Coll Cardiol. 2012;60(16):1581–1598. Pubmed Link

O’Gara PT, Kushner FG, Ascheim DD, et al. 2013 ACCF/AHA Guideline for the Management of ST-Elevation Myocardial Infarction. J Am Coll Cardiol. 2013;61(4):e78–e140. Pubmed Link
 
How to identify MI in paced rhythms
Episode 119
December 9, 2013

Can you read ischemia with a pacemaker???


You can diagnose MI in paced rhythms!

  • Paced rhythms cause ST-segment & T wave changes that can make the identification of acute MI difficult

  • Patients with paced rhythms can be expected to have ST segment & T wave changes that are discordant to the direction of the QRS complex

    • ​This is normal & referred to as the “Rule of Appropriate Discordance”

  • ST-segment deviations that are concordant (in same direction) to the QRS complex are abnormal

Sgarbossa’s criteria can be used to diagnose MI,

in the setting of both paced rhythms & LBBB

Here is what to look for:

     1. Concordant ST elevation ≥ 1mm in any single lead

     2. Concordant ST depression ≥ 1mm in either V1, V2, or V3

     3. Excessively discordant ST elevation ≥ 5mm in any lead


​Do you remember what the Modified Sgarbossa rule is & how to use it?

If not, check out …The Modified Sgarbossa Rule


References

Sgarbossa EB. Recent advances in the electrocardiographic diagnosis of myocardial infarction: left bundle branch block and pacing. Pacing Clin Electrophysiol. 1996;19(9):1370–1379. Pubmed Link

Sgarbossa EB, Pinski SL, Gates KB, Wagner GS. Early electrocardiographic diagnosis of acute myocardial infarction in the presence of ventricular paced rhythm. GUSTO-I investigators. Am J Cardiol. 1996;77(5):423–424. Pubmed Link

Maloy KR, Bhat R, Davis J, Reed K, Morrissey R. Sgarbossa Criteria are Highly Specific for Acute Myocardial Infarction with Pacemakers. West J Emerg Med. 2010;11(4):354–357. Pubmed Link

Schaaf SG, Tabas JA, Smith SW. A patient with a paced rhythms presenting with chest pain and hypotension. JAMA Intern Med. 2013. Epub ahead of print. Pubmed Link
How to identify MI in paced rhythms
Episode 119
December 9, 2013

Can you read ischemia with a pacemaker???


You can diagnose MI in paced rhythms!

  • Paced rhythms cause ST-segment & T wave changes that can make the identification of acute MI difficult

  • Patients with paced rhythms can be expected to have ST segment & T wave changes that are discordant to the direction of the QRS complex

    • ​This is normal & referred to as the “Rule of Appropriate Discordance”

  • ST-segment deviations that are concordant (in same direction) to the QRS complex are abnormal

Sgarbossa’s criteria can be used to diagnose MI,

in the setting of both paced rhythms & LBBB

Here is what to look for:

     1. Concordant ST elevation ≥ 1mm in any single lead

     2. Concordant ST depression ≥ 1mm in either V1, V2, or V3

     3. Excessively discordant ST elevation ≥ 5mm in any lead


​Do you remember what the Modified Sgarbossa rule is & how to use it?

If not, check out …The Modified Sgarbossa Rule


References

Sgarbossa EB. Recent advances in the electrocardiographic diagnosis of myocardial infarction: left bundle branch block and pacing. Pacing Clin Electrophysiol. 1996;19(9):1370–1379. Pubmed Link

Sgarbossa EB, Pinski SL, Gates KB, Wagner GS. Early electrocardiographic diagnosis of acute myocardial infarction in the presence of ventricular paced rhythm. GUSTO-I investigators. Am J Cardiol. 1996;77(5):423–424. Pubmed Link

Maloy KR, Bhat R, Davis J, Reed K, Morrissey R. Sgarbossa Criteria are Highly Specific for Acute Myocardial Infarction with Pacemakers. West J Emerg Med. 2010;11(4):354–357. Pubmed Link

Schaaf SG, Tabas JA, Smith SW. A patient with a paced rhythms presenting with chest pain and hypotension. JAMA Intern Med. 2013. Epub ahead of print. Pubmed Link
Orthodromic vs. Antidromic SVT with WPW
Episode 116
November 18, 2013

Orthodromic SVT, antidromic SVT, no big deal. Here’s why.


WPW Syndrome (Pre-excitation)
Shortened or no PR-interval
Widened QRS-complexes
Delta wave (Not always present!)
 
Treat SVT with WPW as per the usual tachycardia algorithms
 

Orthodromic SVT

  • Regular & Narrow complex rhythm 
  • Conduction down normal AV nodal pathway and back up to atrium through an accessory pathway (A.P)
  • Treat like SVT with vagal maneuvers and AV nodal blockade

Antidromic SVT 

  • Regular & Wide complex rhythm 
  • Conduction down accessory pathway (A.P) and back up to atrium through the AV node
  • Treat like ventricular tachycardia with procainamide or cardioversion

Go to the
Resuscitation 2014 website to learn more about a great upcoming conference in Las Vegas! 
 
Check out these previous episodes on SVT & Atrial fibrillation with WPW
 
References:
Orthodromic vs. Antidromic SVT with WPW
Episode 116
November 18, 2013

Orthodromic SVT, antidromic SVT, no big deal. Here’s why.


WPW Syndrome (Pre-excitation)
Shortened or no PR-interval
Widened QRS-complexes
Delta wave (Not always present!)
 
Treat SVT with WPW as per the usual tachycardia algorithms
 

Orthodromic SVT

  • Regular & Narrow complex rhythm 
  • Conduction down normal AV nodal pathway and back up to atrium through an accessory pathway (A.P)
  • Treat like SVT with vagal maneuvers and AV nodal blockade

Antidromic SVT 

  • Regular & Wide complex rhythm 
  • Conduction down accessory pathway (A.P) and back up to atrium through the AV node
  • Treat like ventricular tachycardia with procainamide or cardioversion

Go to the Resuscitation 2014 website to learn more about a great upcoming conference in Las Vegas! 
 
Check out these previous episodes on SVT & Atrial fibrillation with WPW
 
References: