Tan - welcome - I wish there were a quick remedy we could offer for you. Without your history or details of your health history with Afib, it makes it difficult to make suggestions. However, some people have found relief by doing a Val-salva maneuver... or using the EFT - emotional freedom technique (tapping)... which don't involve taking anything orally.
If you can provide more specific details, we can try to offer suggestions.
Is this new or an ongoing problem? What were you doing when the AF started? Age, physical condition? Present health conditions.
Jackie