Can’t miss cases of Wellens Syndrome
Episode 103
August 19, 2013

If you love Wellens ECGs, here’s 4 cases and 16 minutes of love!

​Wellens Syndrome
  • T-wave abnormality in precordial leads (V2-V3, +/-V4)
  • Specific for obstructed LAD lesion
  • High risk for extensive anterior wall MI and death
    • 2 types
      • Type 1-Deeply symmetric TWI
      • Type 2- Biphasic T waves with terminal TWI. Goes up first, then down (often misdiagnosed as “normal” or “non-specific T-wave abnormality”).
  • ST changes are often absent and patient can be chest pain free!
  • Look carefully at the ECG when the machine tells you there are “non-specific ST abnormalities”
  • Cardiac biomarkers often initially normal
  • Medical management usually ineffective and patients are best treated with PCI, treadmill stress testing may be hazardous.
  • Do not diagnose in the presence of large amplitude QRS complexes
  • When in doubt get serial ECG’s!

Knowing how to diagnose Wellens saves lives. Make sure you know about it. These previous episodes will help, check them out…

 
Can’t miss cases of Wellens Syndrome
Episode 103
August 19, 2013

If you love Wellens ECGs, here’s 4 cases and 16 minutes of love!

​Wellens Syndrome
  • T-wave abnormality in precordial leads (V2-V3, +/-V4)
  • Specific for obstructed LAD lesion
  • High risk for extensive anterior wall MI and death
    • 2 types
      • Type 1-Deeply symmetric TWI
      • Type 2- Biphasic T waves with terminal TWI. Goes up first, then down (often misdiagnosed as “normal” or “non-specific T-wave abnormality”).
  • ST changes are often absent and patient can be chest pain free!
  • Look carefully at the ECG when the machine tells you there are “non-specific ST abnormalities”
  • Cardiac biomarkers often initially normal
  • Medical management usually ineffective and patients are best treated with PCI, treadmill stress testing may be hazardous.
  • Do not diagnose in the presence of large amplitude QRS complexes
  • When in doubt get serial ECG’s!

Knowing how to diagnose Wellens saves lives. Make sure you know about it. These previous episodes will help, check them out…

 
AV blocks & Rabbit ears for RBBB vs. PVC
Episode 97
July 8, 2013

Virtually a full review of AV blocks from a single patient…in 14 minutes!​

When interpreting rhythms, always do these three things:
1. Find out what the atrium is doing
2. Find out what the ventricle is doing
3. Figure out the relationship between the atrium and ventricle (PR-interval)

The answer usually lies in the PR-interval!

1st Degree AV Block = “delay” > 200ms at AV node or His bundle.

When the P:QRS>1, consider 2nd and 3rd degree AV Blocks

2nd Degree AV Block = Not every atrial impulse goes through to the ventrcles. (ie P:QRS >1)

  • Mobitz Type I (Wenckebach) -Each atrial impulse has longer and longer delay until it fails to conduct to the ventricle. Progressive PR-interval lengthening before a dropped beat.

  • Mobitz Type II - typically due to block below AV node in His bundle. Some but not all impulses are transmitted to the ventricles WITHOUT progressive PR lengthening.

3nd Degree AV Block = P waves march out normally at 60-100 bpm with no relation to the ventricular rate which is typically slower than sinus or the atrial rate.
 

RBBB vs PVC’s

Wide QRS complexes, with large R waves in V1 can be caused by both RBBB and PVC’s. An RSR’ pattern or the “rabbit ear appearance” is typically seen in V1 with RBBB. PVC’s from a left ventricular source will also have dominant R waves in V1. One way to differentiate between RBBB and a PVC is to pay attention to the morphology of the QRS complex.

 
  • RBBB - typically has a small R wave (left rabbit ear) and a tall R’ (right rabbit ear).
  • PVC’s - will have a larger R wave (left rabbit ear) and a smaller R’ (right rabbit ear) or a “hitched” downslope to the wave.
 

Extra Pearl

R wave > 15mm in setting of RBBB + Rightward Axis = Right ventricular hypertropy (RVH)


Bunny ears not enough? Want more? Check out these related episodes…
 
 
 
AV blocks & Rabbit ears for RBBB vs. PVC
Episode 97
July 8, 2013

Virtually a full review of AV blocks from a single patient…in 14 minutes!​

When interpreting rhythms, always do these three things:
1. Find out what the atrium is doing
2. Find out what the ventricle is doing
3. Figure out the relationship between the atrium and ventricle (PR-interval)

The answer usually lies in the PR-interval!

1st Degree AV Block = “delay” > 200ms at AV node or His bundle.

When the P:QRS>1, consider 2nd and 3rd degree AV Blocks

2nd Degree AV Block = Not every atrial impulse goes through to the ventrcles. (ie P:QRS >1)

  • Mobitz Type I (Wenckebach) -Each atrial impulse has longer and longer delay until it fails to conduct to the ventricle. Progressive PR-interval lengthening before a dropped beat.

  • Mobitz Type II - typically due to block below AV node in His bundle. Some but not all impulses are transmitted to the ventricles WITHOUT progressive PR lengthening.

3nd Degree AV Block = P waves march out normally at 60-100 bpm with no relation to the ventricular rate which is typically slower than sinus or the atrial rate.
 

RBBB vs PVC’s

Wide QRS complexes, with large R waves in V1 can be caused by both RBBB and PVC’s. An RSR’ pattern or the “rabbit ear appearance” is typically seen in V1 with RBBB. PVC’s from a left ventricular source will also have dominant R waves in V1. One way to differentiate between RBBB and a PVC is to pay attention to the morphology of the QRS complex.

 
  • RBBB - typically has a small R wave (left rabbit ear) and a tall R’ (right rabbit ear).
  • PVC’s - will have a larger R wave (left rabbit ear) and a smaller R’ (right rabbit ear) or a “hitched” downslope to the wave.
 

Extra Pearl

R wave > 15mm in setting of RBBB + Rightward Axis = Right ventricular hypertropy (RVH)


Bunny ears not enough? Want more? Check out these related episodes…
 
 
 
Review of Wellens Syndrome
Episode 96
July 1, 2013

Wellens Syndrome

  • T-wave abnormality in precordial leads (V2-V3, +/-V4)
  • Specific for obstructed proximal LAD lesion
  • High risk for extensive anterior wall MI and death
  • 2 types
    • Type 1-Deeply symmetric TWI
    • Type 2- Biphasic T waves with terminal TWI. Goes up first, then down (often misdiagnosed as “normal” or “non-specific T-wave abnormality”).

  • ST changes are often absent and patient can be chest pain free
  • Cardiac biomarkers often initially normal
  • Medical management usually ineffective and patients are best treated with PCI, treadmill stress testing may be hazardous.
  • Do not diagnose in the presence of large amplitude QRS complexes
  • When in doubt get serial ECG’s!

Wellens, make sure you know about it. These will help…


 
Review of Wellens Syndrome
Episode 96
July 1, 2013

Wellens Syndrome

  • T-wave abnormality in precordial leads (V2-V3, +/-V4)
  • Specific for obstructed proximal LAD lesion
  • High risk for extensive anterior wall MI and death
  • 2 types
    • Type 1-Deeply symmetric TWI
    • Type 2- Biphasic T waves with terminal TWI. Goes up first, then down (often misdiagnosed as “normal” or “non-specific T-wave abnormality”).

  • ST changes are often absent and patient can be chest pain free
  • Cardiac biomarkers often initially normal
  • Medical management usually ineffective and patients are best treated with PCI, treadmill stress testing may be hazardous.
  • Do not diagnose in the presence of large amplitude QRS complexes
  • When in doubt get serial ECG’s!

Wellens, make sure you know about it. These will help…


 
Scarbossa’s criteria identifies MI in patients with LBBB 
Episode 94
June 17, 2013

Tombstones, checkmarks, and bundles, oh my!

Criteria for left bundle branch block (LBBB)

  • Widened QRS > 0.12 sec in adults
  • Broad notched or slurred R waves in I and V6 WITHOUT Q-waves
  • Broad S waves in V1, V2, V3, may have a small r wave

LBBB causes ST-segment and T wave changes that make the diagnosis of acute MI difficult. Patients with LBBB can be expected to have ST-segment and T waves that are discordant to the direction of the QRS complex. This is expected and referred to as the “rule of appropriate discordance”. In fact, it is very concerning when the QRS complex and the ST-segment are concordant (point in same direction).

You CAN diagnose MI in LBBB, once you understand Sgarbossa’s criteria.

Sgarbossa’s criteria is used to diagnose MI in the setting of a known chronic LBBB. The following 3 ECG criteria can help diagnose AMI in patients with LBBB.

1. STE ≥ 1mm concordant with QRS deflection in any single lead (odds ratios for AMI of 25.2!)

2. STD ≥ 1mm in V1, V2, OR V3 that is concordant. Does NOT need to be in contiguous leads (odds ratios for AMI of 6.0)

3. Discordant STE ≥ 5mm (lower specificity) or STE >20% of size of QRS.


Everything you nees to know about Scarbossa…
Scarbossa’s criteria identifies MI in patients with LBBB 
Episode 94
June 17, 2013

Tombstones, checkmarks, and bundles, oh my!

Criteria for left bundle branch block (LBBB)

  • Widened QRS > 0.12 sec in adults
  • Broad notched or slurred R waves in I and V6 WITHOUT Q-waves
  • Broad S waves in V1, V2, V3, may have a small r wave

LBBB causes ST-segment and T wave changes that make the diagnosis of acute MI difficult. Patients with LBBB can be expected to have ST-segment and T waves that are discordant to the direction of the QRS complex. This is expected and referred to as the “rule of appropriate discordance”. In fact, it is very concerning when the QRS complex and the ST-segment are concordant (point in same direction).

You CAN diagnose MI in LBBB, once you understand Sgarbossa’s criteria.

Sgarbossa’s criteria is used to diagnose MI in the setting of a known chronic LBBB. The following 3 ECG criteria can help diagnose AMI in patients with LBBB.

1. STE ≥ 1mm concordant with QRS deflection in any single lead (odds ratios for AMI of 25.2!)

2. STD ≥ 1mm in V1, V2, OR V3 that is concordant. Does NOT need to be in contiguous leads (odds ratios for AMI of 6.0)

3. Discordant STE ≥ 5mm (lower specificity) or STE >20% of size of QRS.


Everything you nees to know about Scarbossa…
  ECG findings in Thoracic Aortic Dissection
Episode 93
June 10, 2013

Just a simple inferior STEMI? Don’t be too sure….

About 4-8% of Thoracic Aortic Dissection’s (TAD)
will present with ECG signs of STEMI
  • Usually inferior ST-elevation or diffuse ischemia with ST-depression
  • Typical for inferior STEMI’s to have reciprocal changes in leads I & aVL
  • Consider posterior and right ventricular extension of infarction with inferior STEMI
  • Not all chest pain (CP) = ACS, don’t forget to consider TAD
    • CP + new neurological SSx → TAD
    • CP + new diastolic murmur → TAD
    • CP + new renal failure → TAD
    • CP + new ischemic extremities → TAD
    • Remember that TAD can dissect backward and cause hemorrhagic pericardial effusions…careful with that heparin gtt!


  ECG findings in Thoracic Aortic Dissection
Episode 93
June 10, 2013

Just a simple inferior STEMI? Don’t be too sure….

About 4-8% of Thoracic Aortic Dissection’s (TAD)
will present with ECG signs of STEMI
  • Usually inferior ST-elevation or diffuse ischemia with ST-depression
  • Typical for inferior STEMI’s to have reciprocal changes in leads I & aVL
  • Consider posterior and right ventricular extension of infarction with inferior STEMI
  • Not all chest pain (CP) = ACS, don’t forget to consider TAD
    • CP + new neurological SSx → TAD
    • CP + new diastolic murmur → TAD
    • CP + new renal failure → TAD
    • CP + new ischemic extremities → TAD
    • Remember that TAD can dissect backward and cause hemorrhagic pericardial effusions…careful with that heparin gtt!


Digoxin Toxicity & AV block: Will IV calcium cause “stone heart”?
Episode 91
May 28, 2013
Digoxin Toxicity & AV block: Will IV calcium cause “stone heart”?
Episode 91
May 28, 2013

Potassium, digoxin, calcium, AVBs, stone heart…so much to discuss this week!

  • When considering AV blocks, always pay attention to the PR segments to help distinguish between Mobitz I, Mobitz II, & AVD/CHB.
  • Hyperkalemia can cause just about anything, including AV blocks!
  • Calcium in probably safe in digoxin toxicity.
  • Levine et al. in their retrospective review of 129 patients who had digoxin toxicity, found that IV calcium did not seem to cause malignant dysrhythmias or increase mortality. They found no support for the historical belief that calcium is contraindicated for these hyperkalemic patients.
  Impressive Syndrome
  Impressive Syndrome
Episode 90
May 21, 2013

Impressive horses, syphilis, and strokes…all in 14 minutes!
 
Hyperkalemia is the syphilis of electrocardiography. It is the great imitator!
 
  • Hyperkalemia can cause STE and mimic STEMI’s & is the most rapid killer in DKA
  • Renal patients with systemic complaints should get an ECG and hyperkalemia should be considered
  • Bizarre Rhythm? Wide QRS? Think Tox/metabolic…get Calcium & Bicarb ready!
  • Hyperkalemic periodic paralysis, aka. Impressive Syndrome - Inherited autosomal dominant condition that affects Na+ channels in muscle and the ability to regulate K+ in the blood. 


 
  T-wave changes of severe hypokalemia
  T-wave changes of severe hypokalemia
Episode 89
May 13, 2013

 
Ever heard of “Reverse-Wellens syndrome” ? Watch this to learn about this dangerous Wellens syndrome mimic.
“Reverse-Wellens” waves deflect downward before going up & are seen in cases of severe hypokalemia that produce U-waves. See below…

Compare this to Wellens waves that may also be biphasic, but deflect upward before going down!
What anatomical distribution of ischemia is associated with the ECG changes of Wellens Syndrome? Review Wellens by watching the videos below!  

Review these previous episodes and master Wellens syndrome…

 
  When STE in aVR = Left main coronary artery stenosis
Episode 88
May 6, 2013

aVR - the forgotten 12th lead

  • BEWARE OF STE in aVR for patients with acute coronary syndromes
  • STE in aVR with other ischemic findings on ECG is BAD! (LMCA occlusion, proximal LAD occlusion, or triple vessel disease)
  • In the setting of ACS, STE in aVR…
    • + STE in avL = LMCA occlusion
    • + STE in V1 = LMCA or proximal LAD occlusion
    • STE in avR > STE V1 = LMCA occlusion
    • ST-elevation in aVR not applicable in setting of SVT or in asymptomatic patients without ischemic symptoms
  • aVR STE > 1.0mm should make you worry
  • LMCA occlusion may require CABG, so avoid drugs like clopidogrel
  • 70% mortality without immediate PCI
  • Medical therapy including lytics does not improve mortality
  • Emergent PCI may decrease mortality to 40%
  • Time delay to PCI is the only predictor of survival
  • STE of aVR in very tachycardic rhythms (i.e. SVT), and in the setting of severe hypertension and LVH may be a normal variant or have no clinical significance.

Learn more about the forgotten lead, aVR! This episode is loaded with important references you can share with your cardiologist as needed…

References:
 
 
 
 
 
 
 
 
  When STE in aVR = Left main coronary artery stenosis
Episode 88
May 6, 2013

aVR - the forgotten 12th lead

  • BEWARE OF STE in aVR for patients with acute coronary syndromes
  • STE in aVR with other ischemic findings on ECG is BAD! (LMCA occlusion, proximal LAD occlusion, or triple vessel disease)
  • In the setting of ACS, STE in aVR…
    • + STE in avL = LMCA occlusion
    • + STE in V1 = LMCA or proximal LAD occlusion
    • STE in avR > STE V1 = LMCA occlusion
    • ST-elevation in aVR not applicable in setting of SVT or in asymptomatic patients without ischemic symptoms
  • aVR STE > 1.0mm should make you worry
  • LMCA occlusion may require CABG, so avoid drugs like clopidogrel
  • 70% mortality without immediate PCI
  • Medical therapy including lytics does not improve mortality
  • Emergent PCI may decrease mortality to 40%
  • Time delay to PCI is the only predictor of survival
  • STE of aVR in very tachycardic rhythms (i.e. SVT), and in the setting of severe hypertension and LVH may be a normal variant or have no clinical significance.

Learn more about the forgotten lead, aVR! This episode is loaded with important references you can share with your cardiologist as needed…

References:
 
 
 
 
 
 
 
 
Anteroseptal ischemia or Posterior STEMI? ​
Episode 86
April 22, 2013

Syncope leads to cardiac arrest within 15 minutes. What’s the diagnosis? Find out in 15 minutes!​

Always think of the following differentials every time you are looking at an ECG in a patient who presents with syncope:
  1. Acute Coronary Syndrome
  2. Tachy/Brady-dysrhythmias (AV-blocks)
  3. WPW
  4. Brugada syndrome
  5. Hypertrophic cardiomyopathy
  6. Long/Short QT syndrome
  7. Arrhythmogenic RV dysplasia
 
Differential for ST-Depression in Anteroseptal Leads
  • Posterior STEMI
  • Anteroseptal ischemia
  • Miscellaneous
  • RBBB, Hypokalemia, etc.
Posterior Myocardial Infarction
  • ST-segment depression (STD)  instead of ST-elevation (STE)
  • Usually associated with Inferior MI due to RCA or circumflex occlusion
  • Mirror image of septal MI in leads V1-V2
  • Large R-waves instead of Q’s
  • Upright T-waves instead of T-wave inversions

ECG changes in leads V1-V3

Septal MI

STE

Inverted

T-waves

Q-waves develop over hours

Posterior MI

STD

Upright

T-waves

Tall R’s develop over hours

 

 



 
Anteroseptal ischemia or Posterior STEMI? ​
Episode 86
April 22, 2013

Syncope leads to cardiac arrest within 15 minutes. What’s the diagnosis? Find out in 15 minutes!​

Always think of the following differentials every time you are looking at an ECG in a patient who presents with syncope:
  1. Acute Coronary Syndrome
  2. Tachy/Brady-dysrhythmias (AV-blocks)
  3. WPW
  4. Brugada syndrome
  5. Hypertrophic cardiomyopathy
  6. Long/Short QT syndrome
  7. Arrhythmogenic RV dysplasia
 
Differential for ST-Depression in Anteroseptal Leads
  • Posterior STEMI
  • Anteroseptal ischemia
  • Miscellaneous
  • RBBB, Hypokalemia, etc.
Posterior Myocardial Infarction
  • ST-segment depression (STD)  instead of ST-elevation (STE)
  • Usually associated with Inferior MI due to RCA or circumflex occlusion
  • Mirror image of septal MI in leads V1-V2
  • Large R-waves instead of Q’s
  • Upright T-waves instead of T-wave inversions

ECG changes in leads V1-V3

Septal MI

STE

Inverted

T-waves

Q-waves develop over hours

Posterior MI

STD

Upright

T-waves

Tall R’s develop over hours

 

 


Everything you need to freshen up your skills on this topic…