Study of the Influence of Atrial Dilatation on the Development of Atrial Fibrillation through Its Modeling

Atrial stretching and subsequent dilatation are early markers of hypertensive heart disease (HHD), a condition characterized by slow left atrial (LA) structural and electrical remodeling that increases the risk of arrhythmias. This study aims to investigate the development of atrial fibrillation (AF) episodes through coupled modeling of electrical activity with both elastic and growth and remodeling (G&R) responses.Electrophysiological activity was simulated using the Courtemanche model on different 3D LA patches of adjusted dimensions according to the states of acute stretch and chronic dilatation under study.Different conductance parameters were employed to reproduce the healthy and persistent AF (peAF) electrical conditions, considering in turn the effect of the stretch-activated channels (SACs).The study of the vulnerable window (VW) and the frequency of cardiac arrhythmia generation unveiled a greater vulnerability to the development of AF and a higher re-entrant activity when it comes to an atrial tissue with peAF along with SACs in an acutely stretched state.In a chronically dilated atrial tissue, an increased vulnerability to the development of AF was also observed, with a higher VW as the state of severity of chronic dilation progresses.