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ECGs in the ED.

CASE A 9-year-old boy presents to the emergency department with a complaint of a pounding sensation in his chest and neck. The sensation has been occurring intermittently over the last day. He denies noticing it previously. The episodes last for 1 to 2 minutes and then subside. There is no associated shortness of breath, dizziness, or syncope. He has otherwise been well. He has no exercise intolerance. He denies fever, vomiting, diarrhea, headache, or lethargy. The past medical history is significant for surgical repair of a ventricular septal defect as a young infant.