Document Detail

Effects of the antiarrhythmic drug dofetilide on transmural dispersion of repolarization in ventriculum. A computer modeling study.
MedLine Citation:
PMID:  20851784     Owner:  NLM     Status:  In-Data-Review    
Dofetilide is a class-III drug that inhibits the rapid component of the delayed potassium current ( I(Kr)). Experimental studies have shown that the different layers of ventricular muscle present differences in action potential duration (APD) and different responses to class III agents. It has been suggested that it contributes to APD heterogeneity in the ventricles. However, in vivo studies suggest that the strong cellular coupling reduces APD dispersion in intact heart. The aim of this paper is to study the effect of dofetilide on the action potentials (APs) in isolated ventricular cells and on APD dispersion in a strand of ventricular tissue. A mathematical model of dofetilide effects on I(Kr) has been developed and incorporated into the Luo--Rudy dynamic model of ventricular AP. Our results show that dofetilide induces in midmyocardium cells a faster time-course inhibition of I(Kr) than in endocardial or epicardial cells, and periods of instability with beat-to-beat APs variability. This behavior could favor temporal dispersion of repolarization between the different cells. The results also indicate that although dofetilide increases, the transmural gradient of APD in the ventricular wall, early afterdepolarizations (EADs) did not appear even under strong uncoupling conditions. However, reduced repolarization reserve favors the induction of EADs, even under normal coupling conditions.
Javier Saiz; Julio Gomis-Tena; Marta Monserrat; Jose M Ferrero; Karen Cardona; Javier Chorro
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Publication Detail:
Type:  Journal Article     Date:  2010-09-16
Journal Detail:
Title:  IEEE transactions on bio-medical engineering     Volume:  58     ISSN:  1558-2531     ISO Abbreviation:  IEEE Trans Biomed Eng     Publication Date:  2011 Jan 
Date Detail:
Created Date:  2010-12-21     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0012737     Medline TA:  IEEE Trans Biomed Eng     Country:  United States    
Other Details:
Languages:  eng     Pagination:  43-53     Citation Subset:  IM    
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