Effects of Electrophysiological Remodeling in Human Right Atrium: A Simulation Study

Atrial fibrillation (AF) induces variations in channel characteristics of human atrial myocytes. Data from ex-perimental AF studies was incorporated in a computa-tional model. It was used to investigate the effects of electrophysiological remodeling on myocardial behavior. This model was integrated in a schematic 2D model of human right atrium including the sinoatrial node, crista terminalis, pectinate muscles, and the atrial working my-ocardium. Heterogeneous, anisotropic conduction was re-constructed with the monodomain approach. In both normal and pathological case, the models were excited with 68 bpm by the sinoatrial node depolarizing spontaneously. A slightly decreased conduction velocity was reconstructed in the remodeling case. The repolariza-tion period was abbreviated from physiologically 325 ms to 145 ms. A shortened effective refractory period (ERP) and an attenuated ERP-rate relationship were identified. Both factors provide a substrate for AF recurrence. 1