Minimal model for human ventricular action potentials in tissue.

Area of Science:

• Computational biology
• Cardiac electrophysiology
• Biophysics

Background:

• Accurate modeling of human ventricular tissue is crucial for understanding wave propagation and stability.
• Existing models exhibit significant quantitative differences in action potential duration (APD) and conduction velocity (CV) restitution, impacting reentrant wave dynamics.

Purpose of the Study:

• To introduce a minimal ventricular (MV) human model that realistically reproduces key tissue-level cellular characteristics.
• To compare the MV model's performance with established models (PB, TNNP, IMW) in terms of cellular and tissue dynamics.
• To analyze the stability of reentrant waves across all four models.

Main Methods:

• Developed a minimal ventricular (MV) human model incorporating epicardial, endocardial, and midmyocardial cell properties.
• Compared AP characteristics, APD and CV restitution, and reentrant wave stability with PB, TNNP, and IMW models.
• Assessed dominant frequencies and computational efficiency for all models.

Main Results:

• The MV model accurately replicates AP amplitudes, morphologies, upstroke velocities, APD, and CV restitution.
• Significant differences in APD/CV rate adaptation and reentrant wave dynamics (quasi-breakup, stability, breakup) were observed among PB, TNNP, and IMW models.
• The MV model demonstrated superior computational efficiency (1:31:50:8084 ratio) and realistic dominant frequencies, unlike the IMW model which extended beyond clinical ranges.

Conclusions:

• The MV model provides a computationally efficient and accurate representation of human ventricular tissue dynamics.
• The study highlights distinct reentrant wave behaviors and frequency characteristics among different ventricular models.
• The MV model offers a valuable tool for studying wave propagation and stability in the human heart.