@Mya Symons I, too, resisted the prescribing of beta blockers for POTS -- not by a cardiologist, but by my GP. I finally gave in about a month ago, with mixed results. Yes, they do work to lower and stabilize HR. Without the beta blocker, I was usually able to do nothing upright below my target HR (105 - 110 bpm), and I met the criteria for POTS most days. My HR for gentle activities of daily living (food prep, getting dressed, personal hygiene) often reached the high 120's to low 140's, and up to the 150's for even sedentary activities (talking on phone) if there was an emotional content to the discussion. On beta blockers, my HR has not exceeded the mid-120's, and is frequently much lower -- as low as 52 while seated, and in the 40's sometimes while sleeping. On the medication, I've yet to reach the 30 bpm increase from supine to standing required for a POTS diagnosis, which I previously did in the first minute. I also don't hear/feel my heart pounding anymore. So, it seems my heart is being protected.
But . . . and it's a big BUT, I feel worse. Fortunately, I'm not as cold as I was during the first three weeks on Bisoprolol (1.25 mg at night), and my hands and feet are no longer going numb. Only time will tell if this is due to warmer temperatures, or if my body is becoming accustomed to the medication. Unfortunately, my other increased symptoms are not resolving. I feel more fatigued and drugged, with a "thick" head, and I'm napping longer. I'm having more difficulty focusing my eyes, and they feel weird (no way to explain it -- congested, perhaps), and have regained the "glassy" look they had during my early years with ME. My cognitive problems have worsened. And, it seems more difficult to hold my body upright, whether sitting or standing, not to mention increased back pain. At my next doctor's appointment, I intend to raise the possibility of decreasing the dose to see if I can achieve most of the benefit without the adverse effects. But, I'm already splitting a 5 mg tablet in four (the lowest dose available at my pharmacy), and can't split it any more.
It seems people respond differently to various types of this medication, so there's no way to know which beta blocker might be most suitable for you. I hope the above helps, although it's likely to make you even more hesitant to try the medication. Good luck with your decision.