Before starting bisoprolol, my resting heart rate was around 80-90 BPM, and would sometimes jump up to 120-140 with almost any sort of exertion or stressor. At my current dose of 2.5mg/day, my resting heart rate is down to 60-70, and during spikes usually no more than 100. It's only slightly reduced my susceptibility to these spikes, my heart rate still definitely feels "jumpy", but it makes them much more manageable. I started at 5mg/day, but reduced to 2.5mg (half-pills) due to bradycardia at rest of around 40-50 BPM (especially when resting).

It helped my high heart rate caused by my POTS.