Assertion: atrial fibrillation | /r/CreatedBy | abnormal heart rhythm
Facets:
Source sentences:
text: Atrial fibrillation, commonly known as Afib or AF, is an irregular heartbeat caused by an abnormal heart rhythm that makes the upper heart chambers (the atria) quiver.
text: Atrial fibrillation (also known as Afib or AF) is an irregular heartbeat caused by an abnormal heart rhythm.