Atrial fibrillation is an irregular heartbeat that increases the risk of stroke and heart disease. Signs include dizziness, weakness, and fatigue. Treatment involves medication and lifestyle changes, and sometimes procedures such as cardioversion, ablation, pacemakers, or surgery.
The heart pumps blood to the rest of the body. During each heart beat, the two upper chambers of the heart (atria) contract, followed by the two lower chambers (ventricles). These actions, when timed perfectly, allow for an efficient pump. The timing of the heart’s contractions is directed by the heart’s electrical system.