Dual effects of the small-conductance Ca-activated K current on human atrial electrophysiology and Ca-driven arrhythmogenesis: an in silico study.

By sensing changes in intracellular Ca, small-conductance Ca-activated K (SK) channels dynamically regulate the dynamics of the cardiac action potential (AP) on a beat-to-beat basis. Given their predominance in atria versus ventricles, SK channels are considered a promising atrial-selective pharmacological target against atrial fibrillation (AF), the most common cardiac arrhythmia. However, the precise contribution of SK current () to atrial arrhythmogenesis is poorly understood, and may potentially involve different mechanisms that depend on species, heart rates, and degree of AF-induced atrial remodeling.