Atrial fibrillation (AFib) is an irregular heartbeat that occurs when the upper chambers of your heartbeat out of coordination with the lower chambers, which causes your heart to beat either too slowly or too quickly. It is the most common heart arrhythmia, affecting nearly 3 million people in the US. People with AFib are 5 times more likely to have a stroke and may also develop blood clots, heart failure, and other heart-related complications. If you experience AFib, it may feel like your heart is fluttering or skipping a beat. AFib can be detected on an electrocardiogram (EKG), which records the electrical activity of your heart.
