ECG of the Week – 27th April 2015

Some old ECG's from my collection for this week. These ECG's are from an 80 yr old female who presented with pre-syncope. The three ECG's were performed over the course of an hour.



ECG 1
Click to enlarge 
ECG 2
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ECG 3
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Things to think about

What are the key features of each ECG ?
What the potential causes for the ECG findings ?

ECG of the Week – 20th April 2015 – Interpretation

This week's ECG is form a 73 yr old male who presented to the Emergency Department complaining of 10+ hours of chest pain, sore throat, cough and dysponea. He has an AICD in situ and known cardiomyopathy (EF 25%). Vital signs were within normal limits. 
Check out the comments on our original post here.



Click to enlarge

Rate:
  • Mean ventricular rate 96 bpm
Rhythm:
  • Sinus complexes each followed by unifocal ventricular ectopics 
    • Bigeminy
Axis:
  • Sinus complexes
    • Normal
  • Ventricular ectopics
    • RAD
Intervals:
  • Sinus complexes
    • PR - Normal (~160ms)
    • QRS - Normal (80ms)
    • QT - 400ms (QTc Bazette 380-400 ms)
  • Ventricular complexes
    • QRS - Prolonged (160-180ms)
Segments:
  • Sinus Complexes
    • ST Elevation lead aVR (2mm)
    • ST Depression leads V2-6
    • Down sloping baseline makes ST segments in the inferior leads difficult to assess
  • Ventricular complexes
    • Appropriate discordant 
Interpretation:
  • Bigeminy
  • Diffuse ST depression with ST elevation in lead aVR
The Bigeminy Challenge - 'Seeing the Wood for the Trees'

Multiple PVC's can prove a distraction particularly when trying to assess ST segment change as the PVC's tend to draw the eye. I've used Paint to remove the PVC's from our ECG above and the ST changes in the native complexes are clearly more apparent. You can do this with hard copy ECG's by using bits of paper to cover the PVC's.

PVC's Removed
Click to enlarge


What happened ?

The patient remained in bigeminy and the ST segment changes were seen on older ECG's. Prior angiogram showed diffuse multi-vessel disease. The patient troponin was significantly elevated and a repeat angiogram was performed during which the the left circumflex was stented.

References / Further Reading

Life in the Fast Lane

Textbook
  • Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.

ECG of the Week – 20th April 2015

This week's ECG is form a 73 yr old male who presented to the Emergency Department complaining of 10+ hours of chest pain, sore throat, cough and dysponea. He has an AICD in situ and known cardiomyopathy (EF 25%). Vital signs were within normal limits. 


Click to enlarge
Things to think about

  • What are the key abnormalities on the ECG ?
  • What are the differentials for these ECG findings ?

ECG of the Week – 13th April 2015 – Interpretation

This ECG is from an 89 yr old male with multiple co-morbidities including cognitive impairment, cardiac failure and diabetes. He presented to the Emergency Department with several hours of chest pain and has a PPM in-situ for an unknown indication.
Check out the comments on our original post here. 


Click to enlarge
Rate:
  • 60 bpm
Rhythm:
  • Regular
  • Ventricular paced rhythm
  • Evidence of non-conducted native atrial activity
Axis:
  • LAD
Intervals:
  • QRS - Prolonged (160ms)
  • QT - 480ms
Segments:
  • Discordant ST / T wave changes in leads I, II, III, aVR, aVL, aVF,  V6
    • Expected for paced rhythm
  • Lead V2 
    • Concordant ST elevation
    • Positive QRS complex with ST elevation <1mm
    • NOT an expected change but doesn't met criteria of =>1mm concordant ST elevation
  • Lead V3
    • Excessive discordance using Smith's modified Sgarbossa
    • ST elevation ~3mm with QRS depth of 10mm
    • ST/T wave ratio of -0.33 (3/-10) which is less than the normal threshold of -0.25
    • Example image below
Click to enlarge
  • Lead V4
    • Excessive discordance using Smith's modified Sgarbossa
    • ST elevation ~3.5mm with QRS depth of 9.5mm
    • ST/T wave ratio of -0.32 (3.5/-11) which is less than the normal threshold of -0.25
  • Lead V5
    • Baseline wander and P wave superimposition makes ST segment difficult to see
    • Potential for excessive discordance
  • Disproportionate T wave prominence in leads V2-6

Interpretation:

  • V-paced Rhythm
  • Modified Sgarbossa Criteria positive given excessive ST discordance in leads V3-5 suggesting possible acute myocardial infarction
    • Please note the Modified Sgarbossa Criteria have not been validated in paced rhythms
    • I've emailed this ECG to Dr Smith for his thoughts and opinion on the use in paced rhythms. I will update this post with any thoughts he shares.

What happened ?

Given the patients extensive co-morbidities following discussion with cardiology and patient's family no invasive management was undertaken. The patient had a troponin rise and was treated with optimisation of medical therapy. 

This ECG illustrates the challenges and difficulties of interpreting an ECG with LBBB or paced rhythm. 

I'm not going to go into detail here about the Sgarbossa or Modified Sgarbossa criteria as far clever people than I have done an excellent job of reviewing / developing these decision rules - please check out the references below for more information.

References / Further Reading

Dr Smith's ECG Blog


Modified Sgarbossa Rule AEM 2012 Paper
MDCalc
Life in the Fast Lane
Academic Life in Emergency Medicine (ALiEM)
Textbook
  • Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.

ECG of the Week – 13th April 2015

This ECG is from an 89 yr old male with multiple co-morbidities including cognitive impairment, cardiac failure and diabetes. He presented to the Emergency Department with several hours of chest pain and has a PPM in-situ for an unknown indication.



Click to enlarge



Things to think about


  • What are the key ECG features ?
  • What are you going to do about them ?

ECG of the Week – 6th April 2015 – Interpretation

This week's ECG is from a 32yr old female with a history of palpitations. She takes flecanide and verapamil. She presents to the Emergency Department complaining of palpitations for the last few hours. She is conscious, denies chest pain or dysponea and her blood pressure is normal.
Check out the comments on our original post here.

Click to enlarge
Rate:
  • 132 bpm
Rhythm:
  • Regular
  • Evidence of possible AV dissociation
    • Notching best seen in rhythm strip irregularly occurs at differing portions of QRS ( red circles in abridged rhythm strip below)
Abridged rhythm strip - atrial activity circled

Axis:
  • Right / Inferior (105 deg)
Intervals:
  • QRS - Prolonged (100ms)
Additional:
  • Discordant ST / T-wave changes
  • LBBB morphology
Interpretation:
  • Broad Complex Tachycardia
General DDx include:
  • Ventricular tachycardia
  • SVT with aberrancy
  • SVT with pre-existing block
  • SVT with pre-excitation / WPW
  • Paced rhythm
  • Electrolyte abnormality / toxicological / environmental

 So what does our ECG show ?

The combination of LBBB morphology and right axis deviation is consistent with Right Ventricular Outflow Tract Tachycardia (RVOT). This is a type of monomorphic VT originating from the right outflow tract or tricuspid annulus it is commonly seen in structurally normal hearts and is usually haemodynamically well tolerated. RVOT can be terminated with vagal maneuvers, adenosine and is also sensitive to verapamil. 

Following vagal maneuvers the patient's subsequent ECG is below.

Post vagal maneuver
This ECG shows a combination of sinus rhythm and ventricular ectopics. Note the normal T wave morphology in the precordial leads, inferior axis and lack of epsilon wave in the sinus complexes. The ventricular ectopics share the same LBBB morphology and inferior / right axis seen in the first ECG and are occurring frequently. 

The patient was given iv verapamil and returned to consistent sinus rhythm, long term management will be with plan ablation therapy.

RVOT can also be seen in arrhythmogenic right ventricular dysplasia, you can read more about this condition in the Life in the Fast Lane ECG library (link below).

There is a great and brief overview of idiopathic ventricular tachycardias from the E-Journal of the ESC Council for Cardiology Practice that I would recommend:




References / Further Reading

Life in the Fast Lane

Textbook
  • Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.