Sotolol is not your average Beta Blocker. Part of a warning on Sotolol follows, the link to the entire article is provided. www.webmd.com/drugs/drug-8848-sotalol+oral.aspx
"Sotalol should be used only in certain patients. Before taking sotalol, discuss the risks and benefits of treatment with your doctor. Although sotalol is effective for treating certain types of fast/irregular heartbeats, it can infrequently cause a new serious abnormal heart rhythm (QT prolongation in the EKG)...... If this new serious heart rhythm occurs, it is usually when sotalol treatment is first started or when the dose is increased. Therefore, to reduce the risk of this side effect, you should begin sotalol treatment in a hospital so your doctor can monitor your heart rhythm for several days and treat the problems if they occur."/en.m.wikipedia.org/wiki/Antiarrhythmic
See the "Vaughan Williams" classification section at the above link, you can see that Sotol falls into a different section than Toprol.
Due to the ability of certain drugs to possibly create dangerous heart rhythms under certain circumstances, they long ago learned that leaving benign PVCs untreated is safer than treating them. I wish it were otherwise, I have a Vagally Induced "Benign" PVC affliction in full bloom. I wore a Holter and had 6000 PVCs in 24 hours, too many for my sanity, but the Doctor insists they're benign. My heart goes nuts when I swallow, and goes into guadrigeminy when I lay down, but my Cardiologist is unconcerned. I'm going to try a calcium channel blocker, beta blockers limit the sympathetic nervous system effect on the heart, allowing the parasympathetic system stronger influence. Calcium channel blockers don't limit the sympathetic system, hopefully overriding the vagal component.