Numerical methods for the detection of phase defect structures in excitable media.

Area of Science:

• Cardiology
• Computational Biology
• Biophysics

Background:

• Electrical wave rotation in the heart causes dangerous cardiac arrhythmias.
• Traditional phase mapping identifies rotation regions by phase singularities.
• Recent findings indicate phase defect lines, not singularities, define rotation regions in many cases.

Purpose of the Study:

• To comparatively study three phase definitions for identifying phase defect lines.
• To introduce and compare new phase defect detection algorithms.
• To evaluate methods on both in silico and experimental optical voltage mapping data.

Main Methods:

• Application of three distinct phase definitions to analyze cardiac electrical activity.
• Development and comparison of novel phase defect detection algorithms.
• Validation using simulated data (Fenton-Karma model) and experimental data from human atrial myocyte monolayers.

Main Results:

• Phase definition is more critical than the detection algorithm for identifying spatial phase variations.
• Sharp phase defect lines can be derived from local activation times or transmembrane potential reparameterization.
• Phase defect line lengths measured were (35.9 ± 6.2)mm in the Fenton-Karma model and (4.01 ± 0.55)mm in myocyte monolayers.

Conclusions:

• The study validates phase defect lines as a more accurate representation of cardiac rotation regions.
• Methods are suitable for clinical application, as local activation times are standard in cardiac mapping.
• All developed algorithms and methods are publicly available.