Atrial Fibrillation

Atrial fibrillation is the most common cardiac arrhythmia. With a normal heart rhythm, organized and predictable electrical impulses originate from the sinus node. With atrial fibrillation, multiple chaotic electrical signals originate all over the atria at a very fast rate (about 300 - 600 per minute). The ventricles receive these signals and contract separately from the atria. This process results in an irregular and usually a fast heart rate.

A common heart rate for a patient with untreated atrial fibrillation is between 80 - 160 beats per minute. Since the atria quiver instead of contracting normally, the amount of blood pumped out of the heart with each beat is decreased.