My usual heart rate ranges from 100-150. I was experiencing extreme fatigue and dizziness all the time. I also learned Ihave vaso-vagal syncope. My doctor put me on Toprol XL, my usual heart rate is now in the 75-90 range. However, my blood pressure is much lower, an average of 85/60 sometimes as low as 70/50. The problem is I seem to be blacking-out more often and my arms seem to go to sleep all the time. Do you think the low blood-pressure is something I should worry about? Not being so tired all the time is worth blacking-out when I stand up, but I was wondering if there was anything that would lower my heart rate without these side-effects.