Friday, 9 January 2015

ECG of the Week - 5th January 2015 - Interpretation

This ECG is from a 78 yr old male with known severe dilated cardiomyopathy. He presented complaining of worsening peripheral oedema, anorexia and weakness.
Check out the comments from our original post here.


Click to enlarge
Rate:
  • 72 bpm
Rhythm:
  • Regular
  • A-V Sequential Pacing
  • Nil native cardiac activity
Axis:
  • Extreme Axis Deviation
Intervals:
  • QRS - Prolonged (200-220 ms)
Segments:

  • Appropriate discordance ST segments / T waves
  • Lead V3 not quite isoelectric but there appears to be some concordant ST depression
    • This was non-dynamic with no history of chest pain
    • Need correlation with old and serial ECG's
    • Sgarbossa criteria do not apply to LV / CRT pacing only RV pacing with LBBB morphology

Additional:
  • Ventricular pacing consists of 2 spikes ~40ms apart
    • Likely LV pacing followed by RV pacing
    • Referred to as LV-RV Offset
  • Negative QRS vector leads I, II, III, aVF, V4-6
    • Due to infero-apical lead positioning
  • Wide tall R wave lead V1 & V2
    • Predominant LV capture
  • Notching within QRS complex
    • Likely reflects significant myocardial scarring and injury as does QRS prolongation
Interpretation:

  • Bi-Ventricular Pacemaker / Cardiac Resynchronization Therapy (CRT)

What happened ? 

The patient had worsening uraemia likely secondary to increasing diuretic dosing contributing to his anorexia with general de-conditioning due to chronic illness. He was admitted for medication review with the aim of symptomatic improvement.

More examples 

We've had a couple of other ECG cases with CRT pacing that can be found here:


Further Reading

For more on Cardiac Resynchronization Therapy (CRT) check out the following resources:

References

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.