Optimisation of ionic models to fit tissue action potentials: application to 3D atrial modelling

Area of Science:

• Computational biology
• Cardiac electrophysiology
• Biomedical modeling

Background:

• Accurate modeling of atrial electrical activity is crucial for understanding cardiac arrhythmias.
• Previous models often lack detailed anatomical representation and spatially heterogeneous electrophysiological properties.

Purpose of the Study:

• To develop a 3D computational model of atrial electrical activity incorporating spatially heterogeneous electrophysiological properties.
• To integrate detailed atrial anatomy from the Visible Human dataset into the model.
• To simulate the sinoatrial node's function and atrial excitation.

Main Methods:

• Reconstructed atrial geometry from the Visible Human dataset, including key anatomical features.
• Recorded myocyte action potentials from rabbit cardiac tissue using microelectrodes.
• Developed and optimized generic ionic models for different atrial cell types.
• Incorporated cell-specific ionic models into a 3D whole-atrial model.

Main Results:

• The 3D atrial model successfully exhibited a spontaneously active sinoatrial node (SAN).
• The model demonstrated the ability of the SAN to rhythmically excite the atria.
• The developed modeling process is applicable to image-based reconstruction and simulation of excitable tissues.

Conclusions:

• The developed 3D atrial model provides a powerful tool for studying cardiac electrophysiology and arrhythmias.
• The integration of anatomical detail and heterogeneous properties enhances the model's realism.
• The generic modeling approach is adaptable for simulating various excitable tissues.