EP, ICU: Junctional Tachycardia vs. Ventricular Tachycardia

3 mo old infant s/p VSD repair. Postop. day 1.
Note: Paper speed is at 50 mm/sec.
What is the ventricular rate at baseline?
In the second panel, patient is atrially-paced. What do you observe?
Is this junctional ectopic tachycardia or ventricular tachycardia?

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