Don't sweat your EKG results.
An EKG is a snapshot of your heart's electrical impulses at the singular moment they take the reading. They offer the doctor a clue as to potential issues, which may then require further study, or not. They are also known to throw off many false readings.
Take for example the fact that when I have an EKG it often shows I had a past heart attack, which I have not. I had an EKG in May and I warned the nurse it may show a strange result, but it came back perfectly normal this time.
Then there is the case of my sister who was having classic heart symptoms and went to the doctor. He pronounced her EKG to be perfect and sent her home. Two days later she was having two stents implanted into her cardiac arteries on an emergency basis.
Take EKG results with a grain of salt. They are not the end all and the be all. If you've had a complete cardiac workup in the past and nothing was found, I can't believe a single crazy EKG result is indicative of anything other than a false positive.
My best to you. You are doing the right thing to get checked-out, but don't allow one abnormal reading on an overly sensitive test concern you.