Panel 1 - Baseline for comparison.
Panel 2 - What is the reason for change in QRS morphology?
Panel 3 - Based on this panel, do you want to change your opinion for Panel 2?
Panel 4 - How would you differentiate among the following options? (i) Sinus arrhythmia - sinus bradycardia with escape junctional rhythm, (ii) Accelerated junctional rhythm, (iii) Accelerated idioventricular rhythm and (iv) A 5-beat run of ventricular tachycardia.
What is the clinical significance of this finding in an apparently, asymptomatic infant with cardiomyopathy? What if the mother complaints that the baby has been "fussy" recently?