T-waves in Acute Pulmonary Hypertension ​
Episode 85
April 15, 2013
  T-waves in Acute Pulmonary Hypertension ​
Episode 85
April 15, 2013

T-wave inversions are not just cardiac ischemia! Find out what else they can be….you’ll save a life!

Leftward Axis Differential

  • LBBB
  • Pacer
  • WPW
  • Inferior MI (from Q-waves)
  • LAFB
  • LVH
  • Hyperkalemia
  • Normal Variant

Poor R-wave progression Differential

  • Prior anteroseptal MI
  • LVH
  • High precordial electrode placement
  • Normal variant

New TWI’s, especially in anteroseptal +/- inferior leads = Acute Pulmonary Hypertension = PE until proven otherwise!  



 
How to diagnose acute MI in patients with known LBBB
Episode 83
April 1, 2013

Myth: “You can not diagnose acute MI in patients with LBBB”

Don’t believe it! You CAN diagnose MI in LBBB,

once you understand Sgarbossa’s criteria.

Complete LBBB causes delayed left ventricular depolarization causing a wide QRS (>120 ms in adults). Findings include broad notched (RSR’ or “rabbit ear pattern”) in leads I, aVL, V5, & V6. Also, absence of Q waves in leads I, V5, & V6.

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 appropriate discordance”. In fact, it is very concerning when the QRS complex and the ST-segment are concordant (point in same direction).

Positive concordance = STE or positive T waves in leads with positive QRS complexes

Negative concordance = STD or negative T waves in leads with negative QRS complexes

Sgarbossa’s criteria is used to diagnose MI in the setting of a known chronic LBBB. When combined, the following 3 ECG criteria yielded a sensitivity and specificity of approximately 78% and 90%, respectively.

  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.

Still don’t believe it? Keep watching…

References:

How to diagnose acute MI in patients with known LBBB
Episode 83
April 1, 2013

Myth: “You can not diagnose acute MI in patients with LBBB”

Don’t believe it! You CAN diagnose MI in LBBB,

once you understand Sgarbossa’s criteria.

Complete LBBB causes delayed left ventricular depolarization causing a wide QRS (>120 ms in adults). Findings include broad notched (RSR’ or “rabbit ear pattern”) in leads I, aVL, V5, & V6. Also, absence of Q waves in leads I, V5, & V6.

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 appropriate discordance”. In fact, it is very concerning when the QRS complex and the ST-segment are concordant (point in same direction).

Positive concordance = STE or positive T waves in leads with positive QRS complexes

Negative concordance = STD or negative T waves in leads with negative QRS complexes

Sgarbossa’s criteria is used to diagnose MI in the setting of a known chronic LBBB. When combined, the following 3 ECG criteria yielded a sensitivity and specificity of approximately 78% and 90%, respectively.

  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.

Still don’t believe it? Keep watching…

References:

 Knee pain, diaphoresis, and MI
Episode 81
March 18, 2013
 Knee pain, diaphoresis, and MI
Episode 81
March 18, 2013

An ECG saves the life of a patient with knee pain…huh??!! Check it out in 9 minutes.

Diaphoresis is a serious sign of underlying badness.
Take it seriously. Get an EKG!
Posterior MI
  • STD in V1-V3
  • Tall R waves in V1-V3
  • Upright T waves in V1-V3
  • Turn the ECG upside down and look for ST-elevation or check posterior leads
  • Usually associated with inferior MI, but 5% of posterior MI’s occur in isolation
Remember that TWI in aVL can be the earliest sign of MI? If not, check out the video below

 


 
Obtunded patient? ECG can clinch the diagnosis!
Episode 79
March 4, 2013

A patient presents obtunded, GCS 3, RR 8. The ECG makes the dx!
 
Go through the following steps EVERY TIME you interpret a tough ECG
 
5 Step Approach to ECG Interpretation
  1. Rate and Rhythm
  2. Axis
  3. Intervals
  4. Enlargement
  5. Ischemia & Infarction (Q-waves, ST-segment changes, T-wave inversions)​

​​Recognize abnormalities and stop to think about the differential diagnoses that explain them.

Right Axis Deviation Differential

  • LPFB
  • Lateral MI (from Q-waves)
  • RVH
  • Acute (PE) and chronic (COPD) lung disease
  • Ventricular ectopy
  • Hyperkalemia
  • Na-channel blocking drugs (TCA)
  • Normal thin adults with horizontally positioned hearts
  • Lead misplacement

Causes of QRS prolongation

  • BBB (LBBB or RBBB) or paced rhythm
  • Pre-excitation (WPW)
  • Ventricular ectopy
  • Metabolic/Electrolytes (i.e. acidosis, hyperkalemia)
  • Medications - Na2+channel blocking drug toxicity (TCA’s, Quinidine & Anti-arrhythmics)
  • Nonspecific intraventricular conduction delay (ex. from LVH, hypothermia) or congenital

Causes of QT-interval prolongation

  • Hypothermia
  • Hypokalemia (due to U-wave), Hypomagnesemia , Hypocalcemia
  • AMI
  • Increased ICP
  • Na2+channel blocking drugs (TCA’s, Quinidine & Anti-arrhythmics)
  • Congenital

Na2+ channel blocker toxicity (ex. TCA’s)

  • Tall R wave in aVR
  • Tachycardia
  • Right Axis Deviation
  • Prolonged QRS

Approach each ECG systematically so that you don’t miss things. These previous episodes are loaded with pearls and differentials that will help you save lives…

The 5 step approach to ECG interpretation

Deadly, can’t miss ECG!

 

 
 
Obtunded patient? ECG can clinch the diagnosis!
Episode 79
March 4, 2013

A patient presents obtunded, GCS 3, RR 8. The ECG makes the dx!
 
Go through the following steps EVERY TIME you interpret a tough ECG
 
5 Step Approach to ECG Interpretation
  1. Rate and Rhythm
  2. Axis
  3. Intervals
  4. Enlargement
  5. Ischemia & Infarction (Q-waves, ST-segment changes, T-wave inversions)​

​​Recognize abnormalities and stop to think about the differential diagnoses that explain them.

Right Axis Deviation Differential

  • LPFB
  • Lateral MI (from Q-waves)
  • RVH
  • Acute (PE) and chronic (COPD) lung disease
  • Ventricular ectopy
  • Hyperkalemia
  • Na-channel blocking drugs (TCA)
  • Normal thin adults with horizontally positioned hearts
  • Lead misplacement

Causes of QRS prolongation

  • BBB (LBBB or RBBB) or paced rhythm
  • Pre-excitation (WPW)
  • Ventricular ectopy
  • Metabolic/Electrolytes (i.e. acidosis, hyperkalemia)
  • Medications - Na2+channel blocking drug toxicity (TCA’s, Quinidine & Anti-arrhythmics)
  • Nonspecific intraventricular conduction delay (ex. from LVH, hypothermia) or congenital

Causes of QT-interval prolongation

  • Hypothermia
  • Hypokalemia (due to U-wave), Hypomagnesemia , Hypocalcemia
  • AMI
  • Increased ICP
  • Na2+channel blocking drugs (TCA’s, Quinidine & Anti-arrhythmics)
  • Congenital

Na2+ channel blocker toxicity (ex. TCA’s)

  • Tall R wave in aVR
  • Tachycardia
  • Right Axis Deviation
  • Prolonged QRS

Approach each ECG systematically so that you don’t miss things. These previous episodes are loaded with pearls and differentials that will help you save lives…

The 5 step approach to ECG interpretation

Deadly, can’t miss ECG!

 

 
 
Diffuse ST-Elevation Differential 
Episode 78
February 25, 2013

Differential diagnosis for diffuse ST-elevation in several leads

  • Large STEMI
  • Pericarditis
  • Myocarditis
  • Early repolarization
  • Ventricular aneurysm
  • LBBB
  • Hyperkalemia
Look for reciprocal changes to narrow your differentials (STEMI’s & Myocarditis)
 
Don’t forget HIV is an independent risk factor for premature atherosclerosis!
  • Patents have MI’s 10-15 years earlier than the general population.
  • Compliance with antiretroviral medications increases risk even more.
Diffuse ST-Elevation Differential 
Episode 78
February 25, 2013

Differential diagnosis for diffuse ST-elevation in several leads

  • Large STEMI
  • Pericarditis
  • Myocarditis
  • Early repolarization
  • Ventricular aneurysm
  • LBBB
  • Hyperkalemia
Look for reciprocal changes to narrow your differentials (STEMI’s & Myocarditis)
 
Don’t forget HIV is an independent risk factor for premature atherosclerosis!
  • Patents have MI’s 10-15 years earlier than the general population.
  • Compliance with antiretroviral medications increases risk even more.
ECGs that differentiate syncope from “seizure”
Episode 77
February 18, 2013
ECGs that differentiate syncope from “seizure”
Episode 77
February 18, 2013

What do you do with a 12 year old having a second seizure? Or if your nanny has her first seizure? Practical answers in just 13 minutes.

Always get a screening ECG in patients with new onset “seizures”!

  • Remember that juvenile T-wave abnormalities (TWI in V1-V3 through age 8) are normal and can persist in young females (persistent juvenile T-wave pattern).
  • Evaluate ECG for dysrhythmias and syncope (especially prolonged QT)
New T-wave inversions in anteroseptal & inferior leads 
Episode 76
February 12, 2013
New T-wave inversions in anteroseptal & inferior leads 
Episode 76
February 12, 2013

What should you consider when a patient with pneumonia gets worse and flips their T-waves?

Pulmonary embolism (PE) can be associated with normal ECG’s and normal heart rates.

  • Large PE’s commonly cause T-wave inversions (TWI’s).
  • Simultaneous TWI’s in the inferior and anteroseptal leads = PE until proven otherwise 
 
 
One ECG begets another 
Episode 75
February 4, 2013

”One EKG begets another”

- Dr. Corey Slovis

Electrocardiography is the BEST diagnostic test in Emergency Medicine

  • Don’t forget that we are in the business of discovering the most deadly diagnosis…not the most common
  • Repeat the ECG when the patient’s symptoms change (improve or worsen)
  • Young people can have MI’s.
  • Chest pain associated with the following four things should make you consider acute coronary syndromes:
  1. ​Exertion
  2. Radiation (to right>both>left)
  3. Diaphoresis
  4. Vomiting

 
 
 
 
One ECG begets another 
Episode 75
February 4, 2013

”One EKG begets another”

- Dr. Corey Slovis

Electrocardiography is the BEST diagnostic test in Emergency Medicine

  • Don’t forget that we are in the business of discovering the most deadly diagnosis…not the most common
  • Repeat the ECG when the patient’s symptoms change (improve or worsen)
  • Young people can have MI’s.
  • Chest pain associated with the following four things should make you consider acute coronary syndromes:
  1. ​Exertion
  2. Radiation (to right>both>left)
  3. Diaphoresis
  4. Vomiting

 
 
 
 
AV Block in a tachycardic rhythm? 
Episode 74
January 28, 2013
AV Block in a tachycardic rhythm? 
Episode 74
January 28, 2013

Can you have a Mobitz I in a tachycardic patient?? You’ll have an answer in 11min.

Don’t trust the computer’s EKG interpretation…that’s your job!

  • Computer may commonly miss p-waves that are buried in the T-waves.
  • AV Dissociation can be seen in BOTH fast and slow rhythms.
  • When in doubt, map out atrial beats with calipers and search for buried p-waves.
Right Bundle Branch Block
Right Bundle Branch Block
Episode 73
January 22, 2013

Got questions about RBBB? Get some answers in 11 minutes.

ANY ST-ELEVATION IN RBBB IS ALWAYS ABNORMAL!
No special criteria need to be met to have STEMI in RBBB
Uncomplicated RBBB
  • QRS duration > 120ms
  • Tall R wave or R’ in V1 & V2 (conversely, LBBB has an S waves in V1 & V2)
  • ”Wide-ish” S waves in the lateral leads
  • Expected ST-depression and TWI in V1-V3

Concordant STE is BAD! Don’t forget that you can dignose STEMI even in the setting of LBBB or paced rhythms. Watch these for a refersher…