When there first found this back in 2008 I saw a Cardiologist and they did a ultrasound on my heart and said there was no A-fib or anything at all. I just have a Bigeminy which is a extra heart beat, it doesnt happen all the time. Most of the times the Dr. cant even find it, I had to do all these tests because I was active duty military and they needed to clear me for deployment. So I did all the test wore a EKG for 24 hours, had numerous ekgs underload, like running and walking. Nothing seemed to trigger it, it just came and went on its own. So I was cleared and they never talk about it now, they said its normal most people have it and never notice. I mean I Crossfit and I think that is really intense and I never fell any different. Plus before Crossfit I was taking Redline a lot to stay awake on deployment and I felt my heart racing then but never anything out of control or any pain.
http://www.medicinenet.com/premature...ions/page4.htm