140? Too high if you aren't exerting yourself or working out. If you are at rest you could be on the cusp of it getting out of control on you and that is not a good idea. I'm w. the guys posts above....make an appt.
I'm with Jerry, could be afib or a ventricular tach. See a doctor ASAP.
If you PR of 140 is at rest, see a doctor. If you are under 60 that HR may be low enough to wait for a doctor appointment in the coming days.
Be ready to go to the emergency room of your local hospital if symptoms get worse or if you have other symptoms.
That is what I think.