Nonspecific T-wave Changes....

HPI:  20 y/o otherwise healthy male presents after syncopal event while playing basketball. He is athletic, plays basketball 7 days a week, and has never syncopized before. There was a prodromal sensation of “lightheadedness”, but he denies other symptoms and is asymptomatic upon ED arrival. EKG is obtained immediately:
 
EKG:

QUESTION:  Are these benign T-wave changes?  What study needs to be obtained to confirm the diagnosis?