I have mentioned this in other places but it is important enough to repeat. My husband was given flecainide for Afib before an ablation. It caused serious side effects for him. The worst was causing him to faint as he was driving my car. He fainted and hit a telephone pole, the car was totaled, and he fortunately not badly hurt. But the drug can be dangerous for some people, and people who are prescribed it need to know this.