Transient accessory pathway conduction block caused by internal electrical cardioversion

Pulsed field ablation (PFA) has been in the spotlight as an alternative to conventional thermal energy ablation given its unique tissue selectivity. The concept of current-day PFA is based on traditional direct electric current catheter ablation, creating nanopores in the cell membrane and resulting in cell death. Membrane pores that are created via electroporation can be either permanent, if the electric field is high enough, or only temporary if the fields are sub-threshold. We report a transient block of the accessory pathway after internal electrical cardioversion via a multipolar catheter placed along the tricuspid annulus. Learning objective: We report a rare case that exhibited a transient accessory pathway conduction block after internal electrical cardioversion via a multipolar catheter placed along the tricuspid annulus. Transient conduction block may be observed by internal electrical cardioversion due to reversible electroporation.