My Son Has Been To The E.R 3 Times In

My son has been to the E.R 3 times in the 3 months for what he describe as an adrenaline rush accompanies by chest pain. He has had a stress test,echocardiogram and several ekg. They were all ok. They gave him protonics which has not helped. He's so worried because he goes to the police academy in July. He is 26,6ft 2 inches, do you have any ideas