I hope the MRI tells you what is causing the problem and that a fix if found.
In the mean time you may want to start taking an aspirin a day to help guard against blood clot formation from the PAC problem... that may also include flutter and fibrillation, which can (with low probability) cause clots to form...not good.
i'm not diagnosed yet - have holter monitor on now - but i feel them right after exercise and here and there for hrs after exercise = how old r you -i'm 41
Thanks for your comments. I am 34. But I have suffered with these crazy things on and off for about 17 years. I've worn monitors, had 2 nuclear test, 100s of ekgs, stress tests. Now the last thing is the MRI which if it does not show any scar tissue they say I am fine and will not need an EP study.
Thanks