With an ECG everything is relative, in the case
of an elevated T wave, it depends on what lead
you are looking at and what is elevated is generally
relative to #1) ST complex elevated above the
isoelectric line after the R wave, and #2) what does
it look like compared to the same lead in an older
ECG with the same patient.

I have a cache of ECGs from patients I have treated
over the years, unfortunately only about half are 12
lead, some are 16 lead, but all in all most are 4 lead
which are not at all diagnostic.

A really great book for simple 12 interpretation is
put out by Mosby, check it out.