Review Question - QID 212756

A 26-year-old man presents to the emergency department after losing consciousness at a jiu jitsu competition. The patient was choked and lost consciousness briefly for roughly 10 seconds before returning to his baseline level of consciousness without any confusion. He is presenting to the emergency department for further evaluation. The patient generally does not see his primary care physician but is otherwise healthy. His temperature is 99.3°F (37.4°C), blood pressure is 122/88 mmHg, pulse is 77/min, respirations are 14/min, and oxygen saturation is 99% on room air. Basic laboratory studies are performed and are unremarkable. An ECG is performed as seen in Figure A. Current cardiac troponins are pending. Which of the following is the most likely diagnosis?