Bidomain ECG simulations using an augmented monodomain model for the cardiac source.

Area of Science:

• Computational biology
• Biophysics
• Medical imaging

Background:

• Electrocardiogram (ECG) simulations are crucial for cardiac function assessment.
• Bidomain models offer high biophysical detail but are computationally expensive.
• Existing pseudo-bidomain and extracellular potential (φ(e)) recovery methods have limitations in accuracy and computational efficiency.

Purpose of the Study:

• To develop a computationally efficient pseudo-bidomain formulation for ECG simulations.
• To accurately incorporate bath-loading effects and finite bath conditions into ECG modeling.
• To achieve results comparable to full bidomain models at a reduced computational cost.

Main Methods:

• Developed a novel pseudo-bidomain formulation combining an augmented monodomain model with infrequent bidomain solves.
• Incorporated effects of bath-loading and finite surrounding medium.
• Validated the model against full bidomain simulations for activation sequences, ECG traces, and φ(e) distributions.

Main Results:

• The proposed model achieves ≈ 10% of the computational cost of full bidomain models.
• It accurately reproduces bidomain wavefront shapes and activation patterns, including bath-loading effects.
• Simulated extracellular potential (φ(e)) distributions closely match full bidomain results in a bounded medium.

Conclusions:

• The novel pseudo-bidomain model offers a significant reduction in computational cost for ECG simulations.
• It accurately captures essential biophysical phenomena like bath-loading and finite bath conditions.
• This approach provides a more efficient and accurate method for ECG computation compared to previous techniques.