I guess that depends on how you define "Open Heart".
To the best of MY understanding, it IS "Open Chest".
FWIW, several of our members have had good success controlling A-Fib with Sotalol (the generic form of BetaPace).
Then there is the 'SledgeHammer' of antiarrhythmics, Amiodarone (and it's laundry list of nasty side effects if used in too high a dose or for too long... Do a Search on VR.com for Amiodarone to read the MANY discussions of this drug and it's effects, or GOOGLE, or get the package insert from a Pharmacist).
'AL Capshaw'