When they were trying to control rate with JUST beta blockers... I took 200 of propranolol and 300 of metoprolol
and occasional 100 of labetalol
here and there. It helped but it worked a LOT better when other classes of drugs were added. Since the point is to slow you down, it generally SLOWS you down. When I was on THAT much, I felt like I was nailed to the couch. Now, instead I take coreg as a beta blocker and diltiazem, and flecainide and lisinopril.