I've had colonoscopies and versed was used each time.... no problem whatsover with my afib during the procedures. I've also had versed during cardioversions as well. It's a fairly gentle anesthesia and I've never experienced side effects as a result.
I suffer from pacs/pvcs and I've had aboout 3 colonoscopies over the last 15 years and am due for another one now. They have never upset the amount of my pacs/pvs but it is always in the back of my mind especially when you have to fast for nearly 24 hours and drink that stuff that evacuates your bowel - that's probably the most unpleasant part of the whole procedure. The last time I did this, I also asked for an examination of my esophagus which showed up that I have a hiatus hernia (I thought if I'm going to be out for this, they may as well do both ends). Not that they do, but just in case, I made sure I told the docs that if they do use the same camera, that they do the esophagus examination first (lol).
I was having tens of thousands of pvcs/day and had no problem with a colonscopy. In my case, the versed really helps to calm my heart.
Hope the procedure goes well and that you have a great outcome!
I worry a lot about procedures affecting my heart, too, but I've had Versed and contrary to what I feared, it brought my heart rate down quite a bit and I didn't have a single PVC.
The worst part about a colonoscopy is having to drink a gallon of the PEG (Colyte) preparation the night before.