Bradycardia how low is too low

Too low is individual, but too low for any individual is what makes them susceptible to falls, fainting, feeling unwell, dizziness, brain fog, poor motility in the gut after eating or when trying to evacuate bowels....that kind of thing.
My stepmother was shaken awake by nurses this morning from a very, very, deep sleep. Her diastolic pressure was a mere 27. :-O
Your heart rate when asleep or when awakening after sleeping is generally a good measure of overall health. Forty (40) is low, but not crazy low. My own, when a fit 35 year old competitive runner, seated at the table, was 34-38. Rising from a table, most hearts respond quickly and will briefly run up to 80-110 BPM, but only for a few seconds, maybe 20. Then, walking to a bathroom or to the kitchen sink, it should settle down to well under 100, even down to 75-85, but depending on the person and their health....and age.

Mine stays at between 45 and 55 for 30 years. No symptoms. They all say "athletic conditioning" (runner/swimmer). Cardio-doc says "Nah. You are old and have Brady. Go for echo and mri."
I figure if my bpm is half, my ❤️ will go twice as long.
p.s. tests showed benign left ventricular arrhythmia and oversized left atrium. Still getting Holter monitor and echocards. Thanks to my cardio-doc for taking good care of me, and says "Keep swimming."

According to the AI on my computer there is actually something to the notion that a slower beating heart will save "wear and tear" over the course of a lifetime. A kind of low mileage outlook. There are some tradeoffs, but I was prompted to discuss this possibility with my cardiologist. It was suggested that my heart has beat 900 million fewer times than someone with a heart beating just 25 bpm faster on average over my lifespan (age 74).

I don't know if it's actually true, but I used the same logic when I was a fit runner with an average heart rate near 50 BPM all day long, except when running, and of course it was much lower when asleep or sedate. Unfortunately, sleep apnea did me in and my heart turned to fibrillating in its left atrium to alert me. By then, the heart was disordered, so the damage was done. I'm doing well now, after treatment, but there were times when my heart was beating close to 150-180 BPM when I was fibrillating.

I had bradycardia for almost a year, and we were just watching it - this while having AFib for approximately 7 years, that was well controlled by Flecainide. The heart rate averaged between 40 to 50 BPM. Then it suddenly started dropping into the low 30’s. In March of this year I went into a junctional rhythm with the bradycardia, which you see with sick sinus rhythm. This precipitated the need for a pacemaker, which was done on 7/25/25.