How low is a low heart rate and how does in relate to beat blockers used for anxiety?

Beta blockers likely: 60 beats a minute is the lower limit of normal. Beta blockers will slow the heart rate. If the rate falls below about 45 or you have dizzy spells, you need to notify your doctor so that he/she can modify the dose.

Less than 60: Less than 60 beats per minute is considered slow. Beta-blockers decrease heart rate and blunt the stress response. If you are having excessively slow heart rates while taking beta-blockers you should talk with your doctor about lowering the dose or a different medication.

Just "numbers": Heart rates vary from person to person and in the same person and "rate" (heart beats per minute) varies in the name person in a wide range while awake and lower rate but still wide range while asleep. Heart rates below 60 beats per minute are considered "low" but are VERY NORMAL. Beta blockers LOWER the heart rate. Anxiety (eg: about your heary) will raise it !