Final answer:
The most common rhythms in pediatric cardiac arrest are asystole and bradycardia, whereas ventricular fibrillation and tachycardia are less common, with AEDs used for defibrillation in emergencies.
Step-by-step explanation:
The most common rhythms seen in pediatric cardiac arrest are asystole and bradycardia. Asystole represents a lack of electrical activity in the heart and is often referred to simply as flatline. Bradycardia is a slower than normal heart rate for the patient's age. In contrast, ventricular fibrillation (VF) and tachycardia are less common in pediatric cardiac arrests. VF is a type of arrhythmia where the ventricles of the heart quiver rather than pump due to disorganized electrical activity, which can be a medical emergency requiring defibrillation. Pediatric tachycardia is a heart rate that is unusually high for the child's age. Automated External Defibrillators (AEDs) can be used to restore a normal rhythm in cases of ventricular fibrillation.