The process can be lengthy, and you will be required to lay perfectly still throughout. That alone will lead to discomfort. The actual ablation process employs the heating of tissue, an actual burn. The experience is said to be uncomfortable to painful. While I underwent the procedure, I had general sedation and remember absolutely nothing after scooting from my bed to the lab table. So I can't tell you from my experience or if there was any pain involved. Now, I been around this forum for over 8 years, and have seen a lot of people come and go.
Some people endured the experience with minor pain. Several forum members reported pain severe enough that they began squirming and the procedure was stopped and scheduled with sedation. Others were frightened to a point that the procedure was never commenced beyond the leg puncture. Another factor to consider is the comfort of the electrophysiologist. He wants to be able to focus on his task, rather than your physical comfort. If he knows your sedated and can feel nothing, he can proceed with confidence. I would suggest that you forget about what you've read regarding the procedure. and rely on the experience of the electrophysiologist to determine if you need sedation or not. I also wish you luck, and I hope they can locate eliminate the source of your issues.
I had an EP study awake but very comfortable. They do give you some sort of medication to where you are awake but out of it. The plan was to do the study like that and if he got what he needed to proceed with ablation he would then put me out. He couldn't provoke my arrythmia's long enough for mapping and so I didn't have the ablation.
I didn't feel any pain from the actual study that I recall. I felt my heart racing and pounding but it didnt hurt.
I had very little sedation during my ablation, some people describe twilight sleep, but I was definitely awake the whole time. I genuinely don't think the sedation did an awful lot, it made the room spin for a few seconds but I didn't feel at all sleepy or out of it!! So if you're keen on staying awake, I think you'll be fine. My procedure wasn't very long though, I think about 2 hours in total.
In terms of the actual ablation, whilst some people freaked me out beforehand and said it was very sore, mine was fine. The ablating only lasts a minute or so at a time and is very bearable, I didn't feel the need to ask for any pain killers at any time, I think I would have to describe it as intense heart burn, it felt like it travelled down my arm and was more sore there than in my chest! But definitely bearable and didn't linger.
Let us know how you get on! Good luck :)