ECG of the Week – 7th April 2014 – Interpretation


This week's ECG is from a 14yr old female who presents following an episode of palpitations and associated dizziness.
Check out the comments on our original post here.
 
 


 
 
Click to enlarge
Rate:
  • 110-115 bpm
Rhythm:
  • Regular
  • Sinus rhythm
Axis:
  • Normal
Intervals:
  • PR - Short (80ms)
  • QRS - Prolonged (120ms)
  • QT - 340ms (QTc Bazette 460 ms)
Segments:
  • ST Elevation leads aVR, V1-2
  • ST Depression leads I, II, III, aVF, V4-6
Additional:
  • Delta waves best seen inferolaterally
  • T wave inversion leads I, II, III, aVF, V3-6
  • 'Pseudo' left ventriclar hypertrophy
    • Prominent R waves leads I, II, III, aVF, V4-6
    • Deep S waves leads aVR, aVL, V1-2
Interpretation:
  • Wolff-Parkinson-White
    • Right anteroseptal pathway - using Arruda algorithm
    • Voltage & ST/T changes secondary to pre-excitation
    • Patient requires referral for an EP study.
 
The right anteroseptal pathway can be difficult to ablate due to the close proximity of the AV node and risk of AV nodal injury during ablation. Cryothermal ablation and careful mapping may be required rather than RF ablation. A more detailed review of septal accessory pathways and ablation techniques can be found here:
  • Macedo PG, Patel SM, Bisco SE,Asirvatham SJ. Septal Accessory Pathway: Anatomy, Causes for Difficulty, and an Approach to Ablation. Indian Pacing Electrophysiol. J. 2010;10(7):292-309. Full text here (html). Full text here (pdf).

There are two commonly used algorithms to identify accessory pathway location from the surface ECG, the Arruda algorithm and Milstein algorithm. Pictorial representations of both can be found here. You can also download a free app called EP Mobile which incorporates both algorithm's in addition to lots of other useful EP formulas (iTunes or Google play) [I have no affilitation with the app or it's developers]

References / Further Reading
 
Life in the Fast Lane
  • Wolff-Parkinson-White here
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 – 7th April 2014

This week's ECG is from a 14yr old female who presents following an episode of palpitations and associated dizziness.



Click to enlarge
VAQ Corner

A 14yr old female presents to your Emergency Department following an episode of palpitations associated with dizziness.


Vital signs: BP 105/58 RR 16 Sats 99% RA Temp 36.7 C 

  • Describe and interpret her ECG (100%)

ECG of the Week – 31st March 2014 – Interpretation

The following is a rhythm strip from a 77yr old male. He has a history of hypertension and hypercholesterolaemia. He complained of chest pain during this ECG recording.
Check out the comments from our original post here.



Click to enlarge

Lead II Rhythm Strip - Total time 20 seconds


Rate:

  • ~95 bpm
Rhythm:

  • Regular
  • Sinus
    • Lots of baseline artifact
Axis:

  • Unable to assess
Intervals:

  • PR - Normal (~200ms)
  • QRS - Normal (100ms)
  • QT - 360ms (QTc Bazette 450-460 ms)
Segments:
  • ST elevation <1mm
Additional:
  • Initiation of PVT / VF 3 seconds prior to end of rhythm strip
    • Short-long cycle initiation secondary to PVC
Interpretation:
  • PMVT/VF with QTc Prolongation
What happened ?


Pre-hospital the patient underwent successful DC cardioversion. On arrival to the Emergency Department the patient has ongoing chest pain and a further 3 episodes of PVT/VF which responded to DC cardioversion.
ECGs whilst in the Emergency Department did not show definitive ST segment changes but 
the patient's medications included amlodipine which was ceased on admission.

Coronary angiogram showed:
  • RCA - Dominant -  30% proximal lesion
  • LMCA - Normal
  • LAD - 60% proximal
  • LCx - distal 80% - stented
Echo
  • Antero-apical hypokinesis
  • Preserved LV function
Following stent insertion an AICD was inserted given episode of QT prolongation and recurrent tachyarrhythmia.
In the setting of QT prolongation refractory VT/VF can be difficult to treat and urgent cardiology input in advised, in these settings amiodarone can further prolong the QT and should be avoided. Underlying causes need to be corrected including ceasing drugs known to prolong QT, correcting electrolyte abnormalities, and treating ischaemia.

References / Further Reading

National Guidelines
  • Australian Resuscitation Council - Managing Acute Dysrhythmias - here
Life in the Fast Lane

List of QT Prolonging Drugs



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 – 31st March 2014

The following is a rhythm strip from a 77yr old male. He has a history of hypertension and hypercholesterolaemia. He complained of chest pain during this ECG recording.




Click to enlarge

VAQ Corner

A 77yr old male presents to your Emergency Department complaining of chest pain. History of hypertension and hypercholesterolaemia. 

a) Describe and interpret his ECG (30%)
b) Outline your management (70%)

ECG of the Week – 24th March 2014 – Interpretation

Another old case from my collection. I don't have any clinical information on the patient or clinical presentation.
Check out the comments on our original post here.



Click to enlarge
Rate:
  • 36
Rhythm:
  • Complexes 1-5
    • Regular
    • R-R Interval ~1500ms 
    • Followed by pause
  • Complex 6
    • Occurs ~2600ms following complex 5
      • Less than 2x preceding R-R interval
  • No p waves visible
Axis:
  • RAD
Intervals:
  • PR - Nil visible p waves
  • QRS - Prolonged (120-140ms)
  • QT - 400ms
Segments:
  • ST Elevation leads II, III, aVF
  • ST Depression leads aVL, V1-5
Additional:
  • T inversion leads II, III, aVF
  • Artifact along baseline
  • Wandering of baseline prior to 3rd complex and after 6th complex
  • ? Pacing spike following 2nd complex likely artifact as nil further evidence of PPM activity


Interpretation:

Differentials for these ECG features may pending on the clinical scenario and patient factors but broadly include:

  • Acute inferior +/- posterior MI
  • Hyperkalaemia - broad, irregular complexes
  • Drug toxicity - sodium channel blockade, digoxin
  • Environmental - hypothermia
  • CNS lesion - bleed, SOL, raised ICP


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 – 24th March 2014

Another old case from my collection. I don't have any clinical information on the patient or presentation.


Click to enlarge
VAQ Corner

A rural hospital has faxed the following ECG to your Emergency Department for an opinion.
You are awaiting a phone call for further clinical information.

a) Describe & interpret the ECG
b) List your differentials for the ECG features