Bradycardia - ¿Atria working?

[S11m]

I believe that there are three indications of Atrial Fibrillation on and ECG:

"Fibrillations" in the T-P section

Irregular pulse rate

Lack of a "P" wave.

My atria have been catheter ablation-ed, so they do not fibrillate (much) - but do they work?

When I had a new pacemaker, they installed an addition atrial lead, and the atria are now paced - and this atria-paced ECG looks different to the ventricle paced ECGs.

When I was an endurance athlete, and my atria worked, a pulse rate of 30 was OK (but I got postural hypotension - even as a teenager).

Before I had a pacemaker, my heart rate was dropping to 35 at night, giving an SPO2 of 75 - I was waking up paralysed from the nose down.

They tell me my pacemaker is set to 60bpm, but it usually drops to 50 at night - and it averaged 51 during this ECG this morning, and was at 50 bpm for much of the night.

Pulse rate and blood pressure do not tell us very much, and it is blood flow and e.g. SPO2 that matters - I felt even rougher than usual when I woke up today, with numb limbs, and I think I was suffering from hypoxia.

Should I try to get them to increase my minimum pulse rate?