What the reason some of ep may not want to stop tambocor (flecainide) before af ablation? n why some of ep want to stop tambocor (flecainide) before af ablation?

Varies: There is no right or wrong answer and the policy varies among cardiologists. It's best to follow the instructions of your EP cardiologist.

Depends: If you are in atrial fibrillation then you can take either approach. However, if you are in sinus rhythm and taking tambocor, (flecainide) I prefer to stop it prior to the ablation to make it easier to induce atrial fibrillation at the time of the ablation. I ask my patients to take an anti arrhythmic after the ablation during the healing phase (3 months) to minimize arrhythmias.