Fiber Organization Has Little Effect on Electrical Activation Patterns During Focal Arrhythmias in the Left Atrium

Area of Science:

• Computational Biology
• Cardiac Electrophysiology
• Medical Modeling

Background:

• Cardiac conduction models are increasingly detailed but challenging to personalize for clinical use due to data limitations.
• Accurate myocardial fiber organization data is difficult to obtain in clinical settings, hindering model personalization.

Purpose of the Study:

• To investigate the impact of varying myocardial fiber organization on cardiac electrical activation patterns.
• To assess the feasibility of using chimeric models with patient-specific geometry and foreign fiber organization for atrial electrophysiology studies.

Main Methods:

• Developed a chimeric computational model of the left atrium using patient-specific geometry.
• Incorporated realistic, but varied and patient-unspecific, myocardial fiber organization data.
• Simulated regular atrial pacing and analyzed spatio-temporal activation patterns.

Main Results:

• Significant variability in myocardial fiber organization showed a relatively small effect on the spatio-temporal activation patterns.
• Activation maps were highly similar across different fiber organization models for a given pacing site.
• Demonstrated the robustness of cardiac conduction models to variations in fiber architecture under regular pacing conditions.

Conclusions:

• Myocardial fiber organization may be less critical than previously thought for predicting atrial activation patterns during regular pacing.
• Chimeric models can provide valuable insights into cardiac electrophysiology despite limitations in obtaining patient-specific fiber data.
• These findings could simplify the personalization of cardiac models for clinical applications.