Sorry to hear the juicing didn't work for you too well, Marie.
Did you ever try to add Celery or even Sea Salt to see if that helped? I think I noticed a little bit more dizzy spells when standing up, because I have AF too. I chalked it up as withdrawal symptoms, so I didn't let it bother me.
I wasn't doing the juice fast for AF though, just to relieve the Toxic Hunger, which it did, fast! (no pun intended. ;)