Sunday, 16 November 2014

ECG of the Week - 10th November 2014 - Interpretation

This ECG is from an 89 yr old female who presented with a week's history of feeling generally unwell and episodic pre-syncope over the prior 24 hours. 
Vital signs: BP 168/67 GCS 15 Sats 96% RA Temp 36.4 C (97.5 F)
Check out the comments on our original post here.


Click to enlarge

Rate:
  • Ventricular rate 42 bpm
  • Atrial rate 105 bpm
Rhythm:
  • Regular ventricular rhythm
  • Regular atrial activity
  • No evidence of atrial to ventricular conduction
    • Number of the P waves are buried in the T waves
    • Atrial activity mapped out in image below
Atrial activity mapped on rhythm strip
Dark green = visible P waves
Light green = mapped location given fixed P-P interval

Click to enlarge
Axis:
  • LAD
Intervals:
  • QRS - Prolonged (120ms)
  • QT - 460ms
Segments:

  • Possible ST elevation leads aVR and V5-6
  • Possible ST depression lead V2
  • Difficult to assess given baseline artefact and relative paucity of ventricular complexes seen in each lead


Additional:


  • RBBB Morphology
  • Prominent T waves leads I, II, aVF, V3-6
  • Voltage criteria for LVH (aVL R wave >11mm)
  • Baseline artefact

Interpretation:

  • Complete heart block
  • Prominent T waves
    • ? Hyperkalaemia
    • ? Ischaemia
What happened ?


There was no history of chest pain and the review of the her medications revealed only low dose calcium channel blocker use. Prior to this attendance she lived independently and alone with minimal prior medical historyAn old ECG on this patient showed long-standing RBBB and LAD in sinus rhythm without evidence of 1st degree AV block with similar T wave prominence as seen in this ECG.  An urgent venous blood gas show no hypo- or hyper-kalaemia and the rest of her electrolytes, renal function and serial troponins were normal.
She was admitted to CCU on an isoprenaline (isoproterenol) infusion and had a pacemaker inserted without complication.

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.