A 31-year-old man with known congenital heart disease, for which he underwent surgery as a child, presents to the emergency department with palpitations that developed while he was jogging.
He reports occasional episodes in the past, but they have usually been short-lived. This episode has lasted for 2 hours and as a result he sought medical care. He is noted to have a heart rate of 270 bpm. The rest of his physical examination is unremarkable.
What is the etiology for the tachycardia?