I had a cardioversion in June of last year. I stayed in sinus rhythm for nearly 7 months. Then I went back into AFib. Like mcordeiro said, everyone is different. I know people who were back in AFib after getting home from the hospital! I have a relative who had 3 cardioversions in 24 hours! So, I feel fortunate to have had mine last 7 months. After my last episode of AFib, I did have another cardioversion. So far, I am in sinus rhythm 6 weeks. I hope it lasts for a LONG time! My EP wants me to have an ablation because he said "You can't be shocked every few months".
1gratefuldawg asked how the cardioversion is administered. Pads are placed on your chest and back. You are given a mild sedative. Then a mild shock is given through the pads (it is like what you see on TV when they try to restart someone's heart - only not as dramatic or as strong a shock). My understanding is that they will try up to three times. If normal rhythm is not established after 3 shocks, it is considered unsuccessful. Both of my cardioversions took one shock. You wake very quickly and can go home (but you need a driver). While I was dreading the experience, it was not bad. Good luck with your road trip!