What Does This EKG Report Mean?

My 8 yr. old son had a EKG test done today to see if he is ok to begin taking Concerta for ADD. We have not had our results explained to us. It says as follows on the print out they gave me: Sinus Rhythm Borderline right axis deviation (QRS AXIS 90 ) Nonspecific T-Wave Abnormality Borderline EKG Should I be worried??