I've been on Atenolol since 2003 for Afib. The Atenolol kept it under control until the last couple of years. I once complained to my family doctor that my blood pressure was so low sometimes that the top number was 85. He said, "yes, and my little old ladies that are in their 90's have lived that long because they haven't worn their hearts out with high blood pressure." So your doctor's may be right -- anyway, sounds like they agree with my doctor.
I took the Atentolol in divided doses, 25-50 mg., checking my bp to make sure it didn't get too low. If I took a whole pill, my bp would plunge.
Hope some of this helps. Good luck.
You'd be foolish to listen to ANYBODY AT ALL WHATSOEVER on the Internet rather than the physicians that know you.
Best bet... find other physicians and have them get to know you. If they agree with the first two... easy decision. If they disagree, then you have something to think about.