What are the long term side affects of Atrial Fibrillation?

If left untreated, Afib can lead your body to build up little clots that could shoot to your brain and cause a stroke. It could also get worse and become rapid afib which needs to be dealt with emergently or it could kill you. Treatment is usually to prevent blood clots - going on blood thinners like warfarin (aka coumadin). If it is a rapid heart rate, medication to bring the rate down and possibly break the afib are given. Some people live in that rhythm all the time on treatment and it is at that point a minor inconvenience. Hope this helps