Electrotonic suppression of early after depolarizations at the Purkinje-ventricular interface

Early after depolarizations (EADs) induce triggered activity in Purkinje (P) fibers that can initiate ventricular (V) arrhythmias. However, it is unclear whether PV interactions suppress or induce EAD formation at the discrete Purkinje-ventricular junctions (PVJs). Using a PV cell pair approach based on the Tan and Joyner coupling circuit, we determined the extent to which EADs initiated in P myocytes were suppressed by coupling to V cells. Our results suggest that PV interactions tend to suppress EAD formation at the PVJ except under pathological conditions (e.g., infarction) in which the V mass is severely reduced.