https://medlineplus.gov/ency/article/000184.htm Encyclopedia: Atrial Fibrillation or Flutter https://medlineplus.gov/ency/article/000184.htm MedlinePlus Encyclopedia: Atrial Fibrillation or Flutter Atrial fibrillation or flutter Atrial fibrillation or flutter National Library of Medicine https://medlineplus.gov/ency/article/000184.htm