New aspects of arrhythmogenesis investigated in a model of EAD-induced cardiac reentry

Since early after-depolarizations (EADs) have shown to trigger cardiac arrhythmia the purpose of this model study is to investigate the mechanisms of their generation process and furthermore to elucidate the mechanisms of EAD-induced reentry circuits, EADs are generated due to the reactivation of the calcium L-type channel during the repolarization phase of the action potential. The most critical consequence of EADs is the pronounced prolongation of the action potential duration, which increases the dispersion of refractoriness. This may locally induce an unidirectional transient block of excitation spreading which favors reentrant circuits