Action Potential Duration Gradient Protects the Right Atrium from Fibrillating

Electrophysiological models for the heterogeneous canine atria: Computational platform for studying rapid atrial arrhythmias

“…Effects of the intrinsic cellular heterogeneities on the atrial AP conduction have been considered previously [22, 23]. However, interatrial heterogeneities in these studies were not based on relevant electrophysiological data.…”

“…However, interatrial heterogeneities in these studies were not based on relevant electrophysiological data. Ultimately, an efficient computational platform for studying the rapid atrial arrhythmias needs to include both the 3D features of atrial geometry [22, 23] and detailed AP models as developed in our study. Experiments aimed at reconstructing the geometry of the canine atria are in progress in our group.…”

Computational Modeling of Electrophysiology and Pharmacotherapy of Atrial Fibrillation: Recent Advances and Future Challenges

“…With these model variants as a baseline for electrical variation throughout the atria, it has been possible to begin understanding the role of electrophysiological heterogeneity both in normal atrial activation, and in AF arrhythmogenesis. During normal activation, the gradient in APD from the sino-atrial node (SAN) toward the atrio-ventricular node (AVN) and the left atrium (LA) ( Ridler et al, 2006 ), is thought to facilitate conduction from the SAN toward the AVN and impede uni-directional conduction block during normal sinus rhythm. However, the role of these APD gradients in atrial arrhythmias is not fully understood, and the manner in which change associated with AF electrical remodeling contribute to arrhythmia is very complex ( Colman et al, 2013 ).…”

“…Patchy tissue heterogeneities in left versus right atria are known to promote AF initiation ( Luca et al, 2015 ), and it has often been suggested that left-right gradients in ion current expression increase dispersion of refractoriness and thereby promote reentrant substrate ( Voigt et al, 2010 ). However, computational studies of the effect of right-left APD gradients in a canine model has found these gradients to be a protective mechanism against reentry, while increasing the complexity of arrhythmia patterns ( Ridler et al, 2006 , 2011 ). These studies highlight the complex effect of atrial heterogeneities and the need for a systematic characterization of the role of spatial variation of cell and tissue properties in AF.…”