My father was just diagnosed with atrial fibrillation. What is that exactly, and why is he on medication for it? The most common heart rhythm abnormality, atrial fibrillation (AF) is when the upper ...

Atrial fibrillation (AF) is a rhythm disturbance in which the atria (receiving chambers of the heart) do not contract normally: instead of regular, forceful contractions which push the blood onwards ...

Atrial fibrillation (AF or afib) is a type of heart rhythm disorder, or arrhythmia. It causes your heart to beat irregularly and can significantly increase the heart rate, leading to your heart’s ...

More people have atrial fibrillation (AFib) than any other kind of irregular heartbeat. And the numbers are only expected to go up as people live longer with heart conditions that go along with it.