Update
My dad came out of surgery earlier this evening and everything appears to be fine. They're going to monitor him overnight but he should probably be able to go home tomorrow. They gave my mom a laundry list of things to look for over the next couple of weeks to make sure that the pace maker is working properly and that there's no infection.
So everything seems to be normal for now. I'll keep everyone updated. I should get to talk to him sometime soon.
Thanks for keeping him in your thoughts.