Glad to hear your pacemaker helped and I hope you had help paying for it.
I have one as well. The cardiologist at the VA who put it in said it the Mercedes-Benz of pacemakers.
Ejection fraction of 21% is pretty low. I had one measurement in the upper teens, but like you, mine is much improved these days.
For a while there I felt drunk half the time. Can’t say enough good things about my implant. I think I was the ideal candidate because my general overall health was so good.