My Husband Has A-fib He Has Been On Sotolol For

My husband has A-fib he has been on Sotolol for awhile. Now his heart rate is in the low 50's sometimes in the 60's. He doesn't feel right, out of breath & tires very easily. He just had an angioplasty and all arties are clear. Our doctor will change his meds only if he goes into the hospital for 3 days in case he goes into A-fib.
do all antiarrhythmic cause the heart rate to go so low? What would you recommend?