Atrial Fibrillation during exercise

I am 29 years old (was 27 when this started happening). When exerting myself I would begin to notice my heart was changing rythm. I had a stress test which came back as Atrial Flutter/Atrial Fib. Later a EP doc said it was Atrial Fib. This only happens when my heart beat goes above 150-160 (depending on how well I feel). Once the afib starts if I just slow down it usually goes back into sinus rythm within 10 seconds or so. I run for 40 min 3 times a week. I used to run a lot, but stopped for a year and then these problems began to come up.
My father struggled with Anxiety at my age and I also have problems with anxiety, though I do not have very much stress in my life right now.
I guess my question is, do I just keep going drug free (was on Toprol XL, but it had bad side affects and effectiveness wore off), or should I look at a procedure to fix this? (note that when I am in afib during exercise my heart rate goes from 150 to 78-80 (slow ventricular response)). My doc says I am very low risk for stroke determined by the medical rule books (less than 1%) good life style. But this limits me from doing some of the things I like to do, like hiking, biking, maybe sports with my kid (prego with first one now). Not sure whether to live with this or try to do something about it. EP doc asked if I wanted an EP study, but decided to put it off at the advice of my GP. Thanks for listening...

[Wisconsin2007]

I haven't heard of a-fib causing a slower heart rate.

For what it's worth, both of my parents have a-fib, and have had it at least since their 40's (they are in their mid-60's now).  My father ran marathons in his 40's, and he believes he had a-fib even then, just that it went undiagnosed until his late 50's/early 60's when he started to have a symptom or two.

The studies I've read online seem to indicate that taking blood thinners at your age present a greater risk to your health than the benefit you'd receive in reduction of stroke risk (I believe the break point for an otherwise healthy person begins around 60 years of age).

I'm not a doctor, and you should certainly get the OK from your doctor first, but from what I've read, I don't see why a person with your condition can't continue to have an active life.  Maybe not hiking up Everest or biking in the Tour de France, but certainly being active.

I hope you can find peace and happiness in your decision, whatever it is.