Hi friend,
Welcome to Health Care Magic
A pulse of 60 to 100 is still in range.
No biological parameter is constant - variation is the rule...
Circadian rhythm /
Beta-blocker (concor) have a role
If you are concerned, HOLTER (24 to 48 hour ambulatory monitoring) may be done for further analysis
Take care
Wishing speedy recovery
God bless
Good luck