Well it looks like I am on here alone answering questions, which stinks cause I dont have all the answers. :( When you talk to your EP ask him, but I would think the enlarged atrium would require a regular cardiologist to keep track of it. I am only guessing and very limited in what I know. I do know the EP is for the AF. EPs are for rythm issues. Sorry, that is pretty much all I know there. The way my doctors office works is first you see the cardiologist, then they will set you up with the EP. So I have both a cardio and EP.
From my own experience I have a cardiologist that checks up on me when necessary (I avoid the visit if I can) and my EP only sees me when he needs to do some work on my heart. He's been in my heart 3 times to do 3 ablation procedures. Other than that, the regular cardio tracks my heart's behavior.
My understanding is people on blood thinners such as coumadin are tested regularly (their INR) to make sure it stays at a certain level. Are you having that done?
If you slip into chronic a-fib then you may have to see the EP again to decide how to manage that.