Friday, 4 July 2014

ECG of the Week - 30th June 2014 - Interpretation

This ECG is from a 70yr old male who presented with chest pain and palpitations.
Vital signs: BP 85/64 RR 20 Sats 98% on 10L/min.
I don't have any more information on the patient's past medical history or current medication.
Check out the comments on our original post here.


Click to enlarge

Rate:
  • 150
Rhythm:
  • Regular
Axis:
  • LAD (~ 80deg)
Intervals:
  • QRS - Prolonged (140ms)
  • QT - 320ms
Additional:

  • RBBB Morphology
    • Typical morphology
Interpretation:

  • Regular Wide Complex Tachycardia
    • Clinical compromise evidence by chest pain and hypotension

General differential diagnosis are:

  • Ventricular Tachycardia
  • SVT with aberrancy
  • SVT with pre-existing conduction delay
  • SVT with pre-excitation
  • Not applicable in this case but don't forget paced rhythms

But what about this ECG. Both of our blog electrophysiologists have reviewed this ECG and feel SVT (likely atrial flutter) with RBBB aberrancy is the likely diagnosis. The QRS activation pattern of rapid activation till QRS peak followed by slower activation is classic for RBBB aberrancy. 
The combination of RBBB and LAHD (left axis deviation) means the SVT exit is the left posterior fascicle (left mid to basal LV), if this was VT it would be a fascicular VT.
I'd encourage our reader to check out the links below for more on VT vs SVT with aberrancy and also on fascicular VT.

What happened ?

Well the patient underwent DC cardioversion in the Emergency Department and his post cardioversion ECG can be found as next week's case here.


References / Further Reading

Life in the Fast Lane

Academic Life in Emergency Medicine


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