Rate-Dependent Role of I_Kur in Human Atrial Repolarization and Atrial Fibrillation Maintenance.

ABSTRACT: The atrial-specific ultrarapid delayed rectifier K⁺ current (I_Kur) inactivates slowly but completely at depolarized voltages. The consequences for I_Kur rate-dependence have not been analyzed in detail and currently available mathematical action-potential (AP) models do not take into account experimentally observed I_Kur inactivation dynamics. Here, we developed an updated formulation of I_Kur inactivation that accurately reproduces time-, voltage-, and frequency-dependent inactivation. We then modified the human atrial cardiomyocyte Courtemanche AP model to incorporate realistic I_Kur inactivation properties. Despite markedly different inactivation dynamics, there was no difference in AP parameters across a wide range of stimul

SUBMITTER: Aguilar M 

PROVIDER: S-EPMC5425383 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature