when I was last in hospital, an 87 year old man in the bed next to me had a pacemaker fitted. Before the procedure, he could hardly walk, even using a frame, and was always
panting/going dizzy. Within one day of the procedure he was walking without the frame
and wasn't panting. His colour returned to normal and I was totally shocked and blown away by the transformation. We spoke about alternatives to a pacemaker and the only
option we could come up with was that I would have to make him jump every couple of
minutes.
I volunteer in a hospital cardiac wing, and work with loved ones who have had heart related surgeries several days a week, and certainly, pacemaker insertions are very common. We get feedback from the patients about their care, etc., and I can't recall anyone who said they had problems other that a sore spot on the chest, but almost all people with pacemaker insertions report greater energy and a better quality of life. I also have a pacemaker, and am feeling great. I would proceed with great confidence and pass that on to your Grandmother. She will sail through this and feel much better, and she will undoubtedly get through the procedure better with your support. Her biggest gripe, according to our feedback and from my own experience will be not being to take a shower for a week.
Grandma is getting a lifesaving procedure with very minimal risk, I'd find a way to support her through the procedure.