Hi, Since I got cfs I have always been plagued with a rapid heart beat on standing or walking. My BP is 100/66 and my heart rate while resting is 82. However when I stand my heart jumps to around 100 within a second and then after a minute im into 120-150. This makes me exhausted and dizzy. I tried a beta blocker in the past and my heart rate was only 60 whilst standing and I could walk for ages without getting tired. But I couldnt tolerate the side effects. Has anyone had a similar issue or got any suggestions?