I am having a 48 hr hear monitor in July for probable AF. I have had daily irregular, sometimes very fast heart beats since at least March. I was on bisoprolol, only 1.25mg fo a short while which di help to calm things a little but still had irregularities 4/6 times daily. (At least!....cos I can’t keep hand on carotid all the time!) The bisoprolol, even at that low dose made me feel I was walking in mud, depressed, in a fog etc ...my pulse ranged from 38 to 170. I walk reasonably briskly twice a day with my dogs covering about 4/6 miles in total. I was diagnosed with breast cancer in 2014 and have had mastectomy, chemo and herceptin, radiotherapy and reconstruction (from my tummy).id like advice for questions to ask cardiologist after monitor. I feel well at the moment though still having irregularities.....resting pulse now 55/60 off tablets. Thank you. Oh yes, I’m 69yr old female.