My 10 Year Old Daughter Had An EKG Done Because

My 10 year old daughter had an EKG done because her BP was high during a routine physical. I think she was just nervous. But the EKG results said "sinus tachycardia : left atrial abnormality and repolarization abnormality suggests LVM. The pediatric physician never mentioned this. I saw it on the paperwork when we got home. What does this mean? She is scheduled for an echo next week. I walked away thinking she was fine.