I am trying to get back to my normal pattern of exercise after a successful cardioversion a month ago. I'm on warfarin and 1.25 mg bisoprolol. My resting pulse is fairly low, around 42 as I type, but I'm not having any ill effects from that and feel generally well. I am wondering what effect the bisoprolol is having when I run as I am getting very out of breath but my heart rate doesn't feel as if it's very high. These are very gentle run / walks on as flat ground as I can find in hilly Yorkshire!