Shown here is the ECG of a 16 year old girl who was taken to the Emergency Department following a feinting episode. She had had several similar episodes in the preceding months but there was no other history to suggest cardiac or neurological disease and she was not receiving any medications. Her physical examination, including a neurological examination, was normal. This ECG was recorded in the Emergency Department. What is your interpretation of the tracing and how would you have managed this patient.