I have an irregular EKG...what could it be?

I am only 17 and I work at Winn Dixie. When I was working one day I suddenly felt like jello all over, real hot, and could not beath. I ped out and was sent to the hospital. They said I had an irregular EKG and moltiple synapsol eppisodes. They told me to follow up with my Dr. and I did but my Dr. said not to worry about it that it was prob. nothing. Well now every time I get to doing things I get like I was before, short of beath and jello feeling and my heart rases and I feel real hot. What am I supose to do if my Dr. won't refer me to a cardiologist? What could it be?