Victor :
the last thing the doctors or nurses want is to have you in pain, you will be given lots of pain meds the first few days. We have said it before, those of us on this side of the mountain, the waiting is the worst!
pacemaker wires are only placed "in case" - after heart surgeries, it is not uncommon for the heart to start beating erratically, or even not at all. The staff are aware of this and watch for it. They leave pacemaker wires in basically for easy access - nurses on the floor (where mine were removed) called them "jumper cables". They never needed to use mine.
As for the breathing tubes, I was kept sedated for 2 full days after surgery, due to pneumonia or some such. I remember drifting awake, being annoyed by them (but not in pain), trying to get my hand up to get them out, and someone making, "no, no leave them" noises, and drifting off again. As I woke up on day 2,removing them was the first thing they did. I don't remember pain, but I do remember releif.
The worst part for me was my surgeon liked his women patients to have their breasts bound; apparently it keeps some pressure off the nice new incicion and helps it to scar nicely. The only thing they could find in ICU was a rib brace. So there I was, all this little metal bumpy things attached to wires, a wired sternum and a whole bunch of what looked like Scotch tape from throat to belly-button, and this rib brace biting in to the whole bunch. I swear I had more pain from that thing than anything else! My mother, who had been at my surgeon's appointment with me as part of my post-op care team had insisted to the ICU staff that I be bound - thanks, mom
At least, you won't have to suffer that indignity!