I Have Been Successfully Treated For Afib And Atrial Tachycardia

I have been successfully treated for Afib and Atrial Tachycardia for 11 years with Atenolol & Flecanaide. Three years ago I started having symptoms of sinus tachycardia which I find very distracting and sometimes occurs daily. I'm in otherwise good health, 62 and enjoying retirement. My Cardiologist says this is a benign condition and nothing to be concerned about. My internist has run blood tests that she thought appropriate. Should a get a 2nd opinion from another Cardiologist or ask for another EP study, when the first one was 11 years ago?