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Ionic charge conservation and long-term steady state in the Luo-Rudy dynamic cell model
T J Hund1, J P Kucera, N F Otani
1Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106-7207, USA.
Biophysical Journal
|November 27, 2001
Summary
Cardiac cell models can drift over time. This study shows that accounting for stimulus current in algebraic and differential methods prevents drift, ensuring accurate simulations of cardiac electrophysiology during rapid pacing.
Area of Science:
- Computational biology
- Cardiac electrophysiology
- Mathematical modeling
Background:
- Cardiac cell models simulating intracellular ion concentrations may violate conservation principles, leading to parameter drift and lack of steady state.
- The algebraic method, using charge conservation to compute transmembrane potential (V(m)), was proposed to address drift seen in the differential method.
Purpose of the Study:
- To compare the Luo-Rudy model's behavior using algebraic and differential methods under prolonged pacing.
- To investigate and resolve the issue of model parameter drift in cardiac cell simulations.
Main Methods:
- Simulated prolonged pacing of the Luo-Rudy cardiac ventricular cell model.
- Compared time-dependent parameters computed via algebraic and differential methods.
- Incorporated ions from stimulus current into calculations.
Main Results:
- Both algebraic and differential methods produced identical results when stimulus current ions were included.
- Neither method exhibited parameter drift under the specified pacing conditions.
- Established a correct pacing protocol for long-term cardiac cell simulations.
Conclusions:
- The inclusion of stimulus current ions resolves drift issues in cardiac cell models.
- The algebraic and differential methods are equivalent and reliable for simulating cardiac electrophysiology during rapid pacing.
- This work provides a validated simulation approach crucial for understanding arrhythmogenesis.
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