Sorry I can't help with any directly related experience, i.e., I don't have a pacemaker. But I do have some of the symptoms and also share the fate of going from rather fit (a running and pretty heavy duty bike rider - not mountain, street, but far and pretty fast). My fatigue comes from medications and reduced efficiency of my heart due to atrial fibrillation.
What other symptoms does you father have? Shortness of breath, low blood pressure, low heart rate...??? The fatigue and a feeling of weakness in the main muscles (legs) can be due to a shortage of oxygen getting to the muscles.
I assume the PM is to assure the heart rate doesn't go too low, i.e., below 50 or 60 you mention. But, does the HR come up when physical activity is undertaken?
What does his doctor recommend relative to physical exercise?
Here are some ideas
blood supply to his legs, an echo doppler can check this
His heart isn't responding to exercise. A stress test or holter monitor can get to the bottom of this
You mention his depression. Depression is common anytime someone's heart show signs of wear and tear. There may be a chance that the issue is entirely psychosomatic. There are many documented cases in the literature where this happens. In most cases it resolves on its own over time, usually taking 6 months+ before a person comes around. Recognizing it can accelerate the process.
Do a blood work to make sure his CBC is OK
Thank you for your response ans ideas..My dad had a stress test and everything showed okay again.
He is booked to have a ultrasound tomorrow and hopefully we can find out why his leg is dragging .I will keep you posted.
So sorry to hear about your dad. I have a pacemaker and had similar difficulties. I was winded at times for doing very easy things such as climbing a flight of stairs. I had the rate response on my pacer checked and that was the problem. I also notice that when I am in AFib, I have a lack of energy. Have they checked for other arrhythmias in your dad?
ksig