Can PAC's change into A-Fib?

I am a 44 year old female.  Post 4 cardiac stents for past blockages.  About a year ago I starting feeling what I thought was skipped beats and fluttering in my chest.  My Cardiologist did a 2 week event monitor and at the end of the study told me I had PAC's.  I educated myself on what those are and I am fine with not treating it.  In May of 2008 I had a fairly major cardiac event that sent me to the emergency room.  They caught A-Fib on the EKG.  Two days later I had a loop recorder implanted into my left chest.  Within the past month I have been told that I have complex a-fib, I am on digoxin, coumadin and many other cardiac drugs.  Now I am being told I am possibly looking at a pacemaker and/or ablation.  I have also been told that due to the complex a-fib I may need an AV node ablation which would make me 100% pacemaker dependent.  I am scared but I have all the confidence in my EP and Cardio doctors.  My question is do pac's typically change into a-fib or is it more likely that someone mis read or diagnosed the pac's to begin with?