Reentry based on the development of early afterdepolarizations in a Purkinje-ventricular muscle ring model

Early afterdepolarizations (EADs) are irregularities that appear in the action potential (AP) of cells before repolarization is complete and that have been implicated in the genesis of certain cardiac arrhythmias, probably in combination with reentry. The purpose of this work was to study the establishment of reentry based on EAD generation and propagation in a ring computer model where Purkinje fibers, under conditions that favor the development of EADs (EAD conditions), connect to ventricular muscle cells, under normal conditions. Our results show that there exist critical EAD conditions under which stimulated APs are followed by two ectopic APs (couplets). This phenomenon is based on the development of triggered activity in Purkinje cells and the subsequent establishment of reentry, and supports the hypothesis suggested by different experimental studies, which propose a similar mechanism to explain the generation of certain cardiac arrhythmias such as torsade de pointes.