Heart rate lowered

[Chasesmun]

So recently my sleeping heart rate when from high ish mid 60s to 70s most of the night and 80s laying in bed to now it’s in the low 70 high 60 s while sitting in bed and down to 58 while sleeping. I’m not healthy so it’s not that in the last week I changed my lifestyle eating better and walking. Seems too soon to notice a change. Anyone else know if a few days can change your heart rate ?

I have an echocardiogram tomorrow from something else