Atrial fibrillation is an irregular and often rapid heart rate that commonly causes poor blood flow to the body. During atrial fibrillation, the heart's two upper chambers (the atria) beat chaotically and irregularly out of coordination with the two lower chambers (the ventricles) of the heart. Atrial fibrillation symptoms often include heart palpitations, shortness of breath and weakness.
Episodes of atrial fibrillation can come and go, or you may develop atrial fibrillation that doesn't go away and may require treatment. Although atrial fibrillation itself usually isn't life-threatening, it is a serious medical condition that sometimes requires emergency treatment. It can lead to complications. Atrial fibrillation may lead to blood clots forming in the heart that may circulate to other organs and lead to blocked blood flow (ischemia).