I'm very sorry to see that this could have been solved with a bit more investigation and maybe time. Did they nuke your AV node? If not, and I'm nothing like a doctor or a nurse, so this may be a silly question, but could they remove the PM and let your heart, maybe with some necessary rehab, continue where it left off?
My reading tells me that, even with well-conditioned and fit hearts, you should keep a lid on your Max HR when exercising. This is commensurate with age. As age rises, our Max HR should fall, year-for-beat, from a theoretical top figure of 220. In your case, it is presumed to be 131 BPM, which I would think is probably pessimistically low...for you. I'm not widely read about this, and really your own performance, perceived effort, and any sensed ill effects would/should be a great guide.
@gloaming Thank you for posting some good ideas for questions that @latuma could ask her EP and cardiologist. I agree that there should have been more investigation pertaining to glaucoma meds causing a temporary drop in heart rate. Knowing the possible side effects of the glaucoma drops would have been helpful, surely others have noted that during studies. One of the problems is that there is such a vast and increasing fact base that medical personnel may have trouble keeping up with (a reason for specialization, why would a cardiologist know the latest on glaucoma drops)? Another issue we have in dealing with medical personnel is that they do not talk to each other or even read charts (I have My Chart) to get the full patient picture. I had a friend that was a NP (nurse practitioner) who encouraged people with multiple issues to have a case manager coordinating their many details. @latuma I am impressed that you are jogging at 79!