Estimating the time scale and anatomical location of atrial fibrillation spontaneous termination in a biophysical model

Abstract

Due to their transient nature, spontaneous terminations of atrial fibrillation (AF) are difficult to investigate. Apparently, confounding experimental findings about the time scale of this phenomenon have been reported, with values ranging from 1 s to 1 min. We propose a biophysical modeling approach to study the mechanisms of spontaneous termination in two models of AF with different levels of dynamical complexity. 8 s preceding spontaneous terminations were studied and the evolution of cycle length and wavefront propagation were documented to assess the time scale and anatomical location of the phenomenon. Results suggest that termination mechanisms are dependent on the underlying complexity of AF. During simulated AF of low complexity, the total process of spontaneous termination lasted 3,200 ms and was triggered in the left atrium 800 ms earlier than in the right atrium. The last fibrillatory activity was observed more often in the right atrium. These asymmetric termination mechanisms in both time and space were not observed during spontaneous terminations of complex AF simulations, which showed less predictable termination patterns lasting only 1,600 ms. This study contributes to the interpretation of previous clinical observations, and illustrates how computer modeling provides a complementary approach to study the mechanisms of cardiac arrhythmias.

Anti-arrhythmic strategies for atrial fibrillation

“…Consistent with the concept of an organized rotor driving AF, it was shown that local catheter ablation may indeed terminate AF by several mechanisms relating to local tissue properties which are increasingly detectable in patients (Rappel et al 2015). Biophysical modeling has also been used to investigate the spontaneous termination of AF, wherein results suggested that termination mechanisms were dependent on the underlying complexity of the arrhythmia (Uldry et al 2012). …”

Recent progress in multi-scale models of the human atria

“…Uldry et al [49] investigated the mechanisms of spontaneous AF termination in two different Conduction is initially blocked from entering the inter-pulmonary region of the left atrium (IPR LA) due to the longer refractory period, and develops into a re-entrant circuit. Colour map represents membrane potential at each node of the anatomical model and arrows indicate wavefront propagation.…”

Comparison of simulated and clinical intracardiac electrograms

“…In silico modeling of atrial fibrillation is adressed e.g. by Aslanidi et al [5] and Uldry et al [6]. A comparison of atrial models published until today is given by Wilhelms et al [7].…”