Whoever is with your mom needs to watch her carefully. Similar things happened to my mom after pace maker surgery. The doctor told her she would be feeling 100% better but she didn't. She couldn't even get out of the bed by herself. Then the hospital wanted to send her to the "step down unit" if she wouldn't go home. Well, the day she was to go to step down unit, she had some type of "event" and we made the nurses call her doctor. We were told she could stay on the Cardiac Unit. One sister and I left for home 2 hours away. One sister stayed with Mom. finally doctor comes to check her out and said they needed to take her back to surgery to "fix something". Well from there everything went downhill. I don't want to scare you too bad, but my Mom never made it out of the hospital. We lost her after a week in ICU due to "complications from pace maker surgery".
Like I said, I don't mean to scare you but just ask questions and watch everything.