Wednesday, 9 September 2015

ECG of the Week - 7th September 2015 - Interpretation

This week's ECG is from a 58 yr old male who presented with abdominal pain and vomiting. 
He is normal fit & well and takes no medication.




Click to enlarge

Rate:
  • Atrial rate ~71 bpm
  • Ventricular rate ~72 bpm
Rhythm:
  • Regular atrial activity
    • Some P waves obscured by PVC's
  • Bigeminy pattern
    • Native QRS followed by PVC's in 1:1 pattern
  • Non-conducted P waves due to early PVC's
  • 4th PVC subtly different morphology potential fusion complex
Axis:
  • Native & PVC's Normal Axis
Intervals - Native QRS Complexes
  • PR - Normal (~160ms)
  • QRS - Normal (80ms)
  • QT - 400ms
Intervals - PVC's
  • QRS - Prolonged (160ms)
Segments:

  • Native complexes normal ST segments
  • Appropriate discordance of ST segments and T waves in PVC's

Interpretation:

  • Bigeminy
  • Underlying sinus rhythm with blocked P waves

There are multiple causes of PVC's and bigeminy including:

  • Anxiety
  • Altered sympathetic tone
  • Drug toxicity
  • Excess caffeine
  • Electrolyte disturbance
  • Ischaemia
  • Myocarditis

Following supportive care and symptom control the patient's ECG showed resolution of the PVC's. Investigations revealed no sinister cause for the presentation and they were discharged.

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.