Sudden Palpitations in the Pediatric Emergency Department

You are leading the care team in the pediatric emergency department. A 6-year-old child weighing 20 kg is brought in after suddenly telling a parent that their heart was racing. The symptoms began about 20 minutes ago while the child was sitting quietly. The child had been well earlier in the day and has no fever, pain, vomiting, diarrhea, breathing difficulty, known heart disease, or known medication or toxin exposure.

The child is alert and speaking. The airway is open, breathing is unlabored, respiratory rate is 24/min, and oxygen saturation is 98% on room air. The pulse is very rapid and regular. Blood pressure is 100/64 mm Hg, the skin is warm, capillary refill is 2 seconds, and peripheral pulses are palpable.

A nurse, respiratory therapist, emergency physician, and medication clinician are present. Pediatric cardiology consultation is available by phone.