Atrial Fibrillation Topic Guide

Atrial Fibrillation (A Fib) Atrial Fibrillation (A Fib): Atrial fibrillation (A fib) describes a rapid, irregular heart rhythm. The irregular rhythm, or arrhythmia, results from abnormal electrical impulses in the heart. Atrial fibrillation may be treated with medications or surgery.




Medical Dictionary