Effect of heart failure-induced electrical remodeling on the initiation of atrial arrhythmias

Heart failure (HF) is a particularly prevalent clinical condition promoting atrial arrhythmias. However, the underlying mechanism is rarely studied. In this study, using a GPU-based simulation, a biophysically detailed computational model of the three-dimensional (3D) sheep atria was implemented to investigate the mechanism by which HF-induced electrical remodeling promoting atrial arrhythmia. At both the single cell and the 3D levels of the sheep atrial model, effects of such HF-induced electrical remodeling on the electrical properties were evaluated. At the cellular level, simulation results demonstrated that the action potential duration (APD) and the amplitude of systolic Ca2+ transient were decreased in all cell types except the PV cell in the HF condition. At the 3D whole organ level, simulation results showed that though localized APDs were shortened, the spatial electrical heterogeneity was maintained in the HF condition, resulting in an increased vulnerability of the tissue for the initiation of the conduction block in response to a premature stimulus. This study provided new insights into understanding the mechanism by which HF promoted atrial arrhythmias.