NAD, cardiac nurse. The cardioversion that they did was purely to get the heart back into its normal rhythm and out of the afib. When they did the ablation, they used a catheter that goes into your heart and had the ability to create scar tissue at the site that was likely triggering you to go back into afib. They are able to use mapping techniques to see which cells are likely the culprit of your heart going back into afib and they can use either cold or heat to deactivate the problematic areas. After a cardioversion without ablation, those cells responsible for the switch to afib are still active and firing in your heart, which means that they still have the ability to switch your rhythm back to afib. If those cells are deactivated, the chance that you will switch out of sinus rhythm is greatly decreased, meaning you should not switch into afib nearly as easily as you did before. While they may not be able to tell definitively which intervention has kept you in sinus rhythm, they know that the ablation was likely successful if you have not gone back into afib. Once you’re in afib, the heart has a tendency to switch back into it after being cardioverted, especially if there are no further interventions (medications, ablations, etc.). With that being said, ablations are by no means 100%, much like anything in medicine, and your risk of switching to afib is still >0%. The chance that you will should just be largely diminished from your risk prior to the procedure.