What is the physiological effect of electrical remodeling on firing rates of myocytes in AF?

Electrical remodeling during atrial fibrillation (AF) leads to significant alterations in the electrophysiological properties of atrial myocytes. A key aspect of this remodeling is the increased activity and firing rates of these myocytes.

During AF, there is often a change in ion channel expression and function, as well as alterations in intracellular calcium handling. These changes facilitate faster depolarization and lead to a heightened automaticity in myocytes. As a result, the overall firing rates of myocytes increase, contributing to the chaotic electrical activity characteristic of AF. This increased automaticity is a driving factor in sustaining the arrhythmia, as myocytes begin to fire more rapidly and are less responsive to normal regulatory mechanisms.

In summary, the phenomenon of electrical remodeling in atrial fibrillation is closely associated with an increase in firing rates among myocytes, which promotes the continuation and exacerbation of the arrhythmic state.