Wednesday, 22 November 2017

ECG of the Week - 20th November 2017 - Interpretation

The following rhythm strip is from a patient who presented with an episode of syncope. Their baseline ECG showed 1st degree AV block with no other abnormal features.



Click to enlarge
Rate:
  • Initial ventricular rate ~50 bpm
  • Mean atrial rate ~54 bpm
Rhythm:
  • Initial regular sinus rhythm rate ~50 bpm
  • Then slowing of atrial rate (5th complex) to ~40 bpm
  • Followed by ~3.8s of ventricular standstill
  • Single ventricular complex
  • Followed by further pause of >9 seconds
  • Persisting P waves throughout
Intervals:
  • PR - Prolonged (~240ms)
  • QRS - Normal (100ms)
Additional:

  • Irregular baseline lead II

Interpretation:

  • Intermittent ventricular standstill

What happened ?

The patient recovered spontaneously from this recorded event and was admitted for PPM insertion. No identifiable or reversible cause was found.

Cause of ventricular standstill include:


  • Myocardial ischaemia or infarction
  • Atrioventricular nodal disease including degenerative and infiltrative
  • Medications including amiodarone, beta blockers, calcium channel blockers and digoxin
  • Electrolyte imbalance
  • Acidosis
  • States of increased vagal tone
  • Hypoxia
  • Hypothermia

References / Further Reading

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