I don't know anything about sotalol, but respond as a fellow heart valve surgery survivor.
I had a successful mitral heart valve repair last November. That solved that problem, my battle with AFig goes on. I understand a high percentage of older people suffer from AFig. As for Toprol, I take that among other drugs, and believe Toprol is at the root of my laziness - my wife thinks it come natural - but I think I had more energy when I wasn't taking Toprol, which started following heart surgery when I ended up with some Atrial Flutter...which converted to the long standing AFig.
Not sure anything here helps, maybe you have some heart surgery stories to exchange : >)
,I can only tell you that I was on sotalol 160mg twice a day for almost five years. Besides being tired when first starting the drug, I've had no problems with it. I have just recently been taken off the sotalol due to having an ablation and now I am on toprol.