hi , just got changed to toprol xl because of supraventricular beats i had a 24 hr montor and i had 2892 supraventricular beats 3% it says is this dangers, and does this mean my heart was racing when it happen because i never felt the racing heart. i just went on atenolol now this toprol xl, its scares me to change meds my heart fluttering now thinking of it . she wants me to go on 50 mg in morning anyone doing this med and how has it been for you . thanks for all input.