88 yr old mom sleeps a lot, hr low, 45-50. is treated w aricept, glaucoma, hearing, & low vitamin d, but is active and mobile. hr cause for concern?

Could: be of concern she should have an ECG and do some thyroid functions none of the medications you listed are usual causes of bradycardia

Not really: If he is still active, that is very good. Her heart rate may cause her to sleep a lot so even if she is asymptomatic otherwise, it is always good to have her doctor monitor this and her other medical problems.

Pacemaker???: Hi. That's a very low heart rate, and may be associated with passing out & falling, which could be disastrous. If indicated, ask her doctor if she needs to be evaluated by a cardiologist for a pacemaker. Good luck to her!