Representing cardiac bidomain bath-loading effects by an augmented monodomain approach: application to complex...

Area of Science:

• Computational Biology
• Biophysics
• Cardiac Electrophysiology

Background:

• The cardiac bidomain model accurately simulates electrical activation but is computationally expensive.
• Standard monodomain models are used for long simulations but lack bath-loading effects like wavefront curvature.
• Cardiac bidomain simulations with surrounding baths show wavefront curvature, a phenomenon not captured by standard monodomain models.

Purpose of the Study:

• Investigate the biophysical origins of wavefront curvature induced by bath-loading in cardiac bidomain models.
• Develop a novel, computationally efficient augmented monodomain-equivalent bidomain approach.
• Faithfully replicate bidomain wavefront morphology and conduction velocity with reduced computational cost.

Main Methods:

• Developed a novel augmented monodomain-equivalent bidomain approach.
• Investigated the biophysical origins of bath-loading induced wavefront curvature.
• Simulated cardiac electrical activation with varying bath conductivity and thickness parameters.

Main Results:

• Identified bath-loading effects as highly dependent on specific conductivity parameters, not bath thickness or conductivity.
• Demonstrated that thin fluid layers (~0.1 mm) can cause significant wavefront curvature in bidomain simulations.
• The augmented monodomain approach accurately replicated bidomain wavefront morphology and conduction velocity.

Conclusions:

• The augmented monodomain-equivalent bidomain approach offers a computationally efficient method for simulating cardiac wavefront dynamics.
• This method faithfully replicates bidomain wavefront morphology and conduction velocity, including bath-loading effects.
• Facilitates fast and accurate long-duration cardiac simulations, aiding experimental comparison.