In normal conditions, there is one dominate pacemaker, the sinus node. In Afib, the cells in the atria are so electrically chaotic that no one focus can be the dominant pacemaker and initiate the electrical cascade. Multiple atrial ectopic foci are firing randomly in AFIB. Each focus stimulates a small area of the of atrial muscle. Ths is why the EKG typically demonstrate erratic, disorganized atrial activity. During this time the AV node is bombarded with impulses at up to 300bpm. Thankfully, the AV node will not allow this kind of conduction. After depolarization repolarization must occur before the AV node can accept another impulse. However, the increased elctrocal signals to the AV node will cause the ventricles to beat irregularly and
