Quantitative roles of ion channel dynamics on ventricular action potential

ABSTRACT

Mathematical models for the action potential (AP) generation of the electrically excitable cells including the heart are involved different mechanisms including the voltage-dependent currents with nonlinear time- and voltage-gating properties. From the shape of the AP waveforms to the duration of the refractory periods or heart rhythms are greatly affected by the functions describing the features or the quantities of these ion channels. In this work, a mathematical measure to analyze the regional contributions of voltage-gated channels is defined by dividing the AP into phases, epochs, and intervals of interest. The contribution of each time-dependent current for the newly defined cardiomyocyte model is successfully calculated and it is found that the contribution of dominant ion channels changes substantially not only for each phase but also for different regions of the cardiac AP. Besides, the defined method can also be applied in all Hodgkin–Huxley types of electrically excitable cell models to be able to understand the underlying dynamics better.

KEYWORDS:

• Voltage-gated ion channels
• dynamics of ionic currents
• contribution analysis
• ventricular action potential
• quantitative analysis

Acknowledgments

We would like to thank Prof. Nazmi Yaraş, Assoc. Prof. Hasan Özdoğan and Dr. Uğur Dalaman from Akdeniz University Biophysics Department for their valuable comments on the manuscript.

Disclosure of potential conflicts of interest

No potential conflict of interest was reported by the authors.

Code availability:

Code is available upon request.

Authors’ contributions

SSA and AKS designed the studies; AKS performed simulation; SSA and AKS analyzed data; SSA and AKS wrote the paper. All authors have seen and approved the final version of the manuscript.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

This study was supported by The Scientific and Technological Research Council of Turkey (TUBITAK 3501, Project No.: 117F020). These funding sources had no involvement in study design, writing of the report, decision to publish, or the collection, analysis, and interpretation of data; TÜBİTAK 3501 [117F020]; TÜBİTAK 3501 [117F020];