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

Area of Science:

• Biomedical Engineering
• Computational Biology
• Cardiovascular Research

Background:

• Realistic cardiac electrophysiology models are advancing, but clinical personalization is hindered by data limitations, particularly myocardial fiber organization.
• Accurate patient-specific models require detailed tissue and cellular data, which is difficult to obtain in a clinical setting.

Approach:

• Investigated a chimeric computational model of the left atrium using patient-specific geometry.
• Incorporated realistic, but patient-unspecific, myocardial fiber organization into the model.
• Analyzed the effect of varied fiber organization on spatio-temporal activation patterns during regular cardiac pacing.

Key Points:

• Significant variability in myocardial fiber organization showed a relatively small effect on the spatio-temporal activation pattern.
• Activation maps during regular pacing were highly similar across different tested fiber organizations for a given pacing site.
• This suggests robustness in cardiac electrical activation patterns despite anatomical variations.

Conclusions:

• Patient-specific cardiac geometry is a dominant factor in determining electrical activation patterns, more so than fiber organization.
• Computational models can be personalized for clinical use even with assumptions about myocardial fiber orientation.
• Further research can explore the impact of fiber organization on complex arrhythmias and abnormal pacing conditions.