Like DeltaDawn23 I too get the Rapid Ventricular Responce and know immediately when I'm in A-fib. I have been shocked 10 times and had two ablations and still have to take Sotalol to stay in NSR. When I was in permanent A-fib the only thing that would keep my rate under 100 was cardizem.
I believe a high and irregular heart rate is always present with AFib.. here I mean fibrillation that last more than a few seconds if that is possible.
In my case undermedicated AFib runs me at about 130. Is undermedicated in that I was under a low dose propafenone following heat surgery and I was in NSR. After about a month I returned to AFib and it was the higher HR that I noticed. I recall my cardiologist calling it atrial flutter at the time, but whatever it did result in permanent AFib. Now at moderate to high beta and calcium channel blockers and my resting HR is in the 80s, but is irregular. My consciously mind is mostly unaware, but I do have some dizziness and shortness of breath and fatigue. This is from a combination of AFib, my medications, and my age. My diagnosis.
I believe anyone subject to even occasional AFib should take some measure to prevent clot formation. I believe for many that is taking an aspirin a day - under direction of a doctor. It is not recommended that people just decide to take an aspirin a day without consulting their doctor... or so it says in the label.
Some people are in afib and do not know it, so I am thinking their heart rate is normal. In my case, I have a rapid ventricular response, with a heart rate anywhere from 150 to 180, so it is impossible to miss it. Sounds like you may have the same thing. Hope this is helpful. Hang in there -- there's hope for us afibbers.