ECG of the Week 31st March 2021 – Answer

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57 y/o female with a background history of metastatic gastric cancer presented with dizziness and light-headedness. She is not complaining of any chest pain or shortness of breath

 

 

Interpretation:

  • Rate: 27
  • Rhythm: Ventricular rhythm
  • Axis: Normal 0-90 degrees
  • Morphology: Twi  in V1

                          Peaked T waves

  • Intervals:  PR –

                     QRS ~114

                     QT interval Corrected (Hodges)  550 msec

  • Summary: Ventricular escape rhythm

Ventricular Escape Rhythm: A ventricular rhythm with a rate of 20-40 bpm.

  • QRS complexes are broad (≥ 120 ms) and may have a LBBB or RBBB morphology.
  • Also known as Idioventricular escape rhythm

The rate of spontaneous depolarisation of pacemaker cells decreases down the conducting system:

  • SA node (60-100 bpm)
  • Atria (< 60 bpm)
  • AV node (40-60 bpm)
  • Ventricles (20-40 bpm)

Under normal conditions, subsidiary pacemakers are suppressed by the more rapid impulses from above (i.e. sinus rhythm). Junctional and ventricular escape rhythms arise when the rate of supraventricular impulses arriving at the AV node or ventricle is less than the intrinsic rate of the ectopic pacemaker.

Causes

Conditions leading to the emergence of a junctional or ventricular escape rhythm include:

  • Severe sinus bradycardia
  • Sinus arrest
  • Sino-atrial exit block
  • High-grade second degree AV block
  • Third-degree AV block
  • Hyperkalaemia
  • Drugs: beta-blocker, calcium-channel blocker or digoxin poisoning

Reference : https://litfl.com/ventricular-escape-rhythm-ecg-library/

Closure:

The patient was commenced on isoprenaline infusion in the Emergency Department and later admitted to CCU and inserted with PPM.