Friday, 20 June 2014

ECG of the Week - 16th June 2014 - Interpretation

This is one of the older ECG's in my collection and I don't have any clinical information on the case other than it's from an 82yr old patient.
Check out the comments from our original post here.

Click to enlarge
Numbered Complexes
Click to enlarge


Rate:
  • Mean ventricular rate ~66 bpm
Rhythm:
  • Irregular
  • Nil p waves visible
  • Complexes #3 & 9 PVC's
Axis:
  • Normal
Intervals:
  • QRS - Normal (100ms)
  • QT - 440ms
Segments:

  • Nil significant change for complexes #1,2,4-8,10,11
  • PVCs - appropriate discordant change

Additional:

  • Baseline signal at ~215 bpm
  • In the precordial leads appearance suggest a possible atrial source
  • In the limb leads the same signal has a bizarre relatively high voltage appearance
  • The limb lead morphology is not consistent with a cardiac source for this signal


Interpretation:

  • Atrial fibrillation with slow ventricular response
  • PVCs
  • Baseline artifact mimicking atrial activity in the precordial leads


Where is the artifact coming from ?

As I said in the case summary, or lack thereof, I don't have any clinical information on this case and no way of identify the case. Both Ken & Jason suggested Parkinson's tremor as the cause and the blog team here agree this is the most likely explanation. It could be another source of movement artifact e.g. drug induced tremor, essential tremor, but again highlights the need to take the ECG back to the patient and look at both together.

References / Further Reading

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