Dyspnea on exertion , normal stress echo, normal pulmonary function test, abn ekg-s-t wave , o-2 sat 100 percent, normal cxr , not fat?

Out of shape?: If you have had your full cardiopulmonary system checked out and everything is 100%, then this may just be a matter of getting into shape. I would recommend restarting an exercise program very slowly and then gradually increasing. If it's not just an exercise thing, then you need to go onto the next step of testing: anemia, thyroid, blood chemistries, asthma eval, etc. Keep looking for the answer!

Cardiac follow up: I would suggest a further cardiac evaluation since there is an abnormality on the EKG.