Fiber Organization has Little Effect on Electrical Activation Patterns during Focal Arrhythmias in the Left Atrium

TL;DR

This study shows that variations in myocardial fiber organization have minimal impact on electrical activation patterns during focal arrhythmias in the left atrium, simplifying modeling efforts.

Contribution

It demonstrates that fiber organization variability does not significantly alter activation patterns in patient-specific atrial models, aiding clinical modeling simplicity.

Findings

Fiber organization variability has little effect on activation patterns.

Activation maps are consistent across different fiber organizations.

Modeling fiber details may be less critical for certain arrhythmia simulations.

Abstract

Over the past two decades there has been a steady trend towards the development of realistic models of cardiac conduction with increasing levels of detail. However, making models more realistic complicates their personalization and use in clinical practice due to limited availability of tissue and cellular scale data. One such limitation is obtaining information about myocardial fiber organization in the clinical setting. In this study, we investigated a chimeric model of the left atrium utilizing clinically derived patient-specific atrial geometry and a realistic, yet foreign for a given patient fiber organization. We discovered that even significant variability of fiber organization had a relatively small effect on the spatio-temporal activation pattern during regular pacing. For a given pacing site, the activation maps were very similar across all fiber organizations tested.