Inducibility of DADs is decreased in cAF due to the stabilizing effect of remodeled IK1.

DADs were induced with either an extra Ca2+ release from the junctional sarcoplasmic reticulum (A–C) or an extra current stimulus (D&E) at the time point of 1 second. Same protocol was used to study four model variants: normal sinus rhythm (nSR), chronic atrial fibrillation with all modifications (cAF: all), only modified inward rectified K+ current (cAF: IK1), and only ryanodine receptor Ca2+ sensitivity (cAF: RyR).