What does the term abnormal but non diagnostic for this age mean? new ekg shows that and nonspecific st depression. he said it was very very minor.

Probably nothing: The computer algorhythms that write the impression on the top of the ekg is very sensitive and will usually say that the ekg is non-diagnostic. Most people have ekg's that say something similar. St depression is describing that a segment of the ekg is a little lower than normal. This is usually completely normal in young people.