| 研究実績の概要 |
The atrioventricular node (AVN) is considered a ”black box”, and the functioning of its dual pathways remains controversial and not fully understood. We have developed a compact, computationally lightweight multi-functional rabbit AVN model based on the Aliev-Panfilov two-variable cardiac cell model. The 1D AVN model includes fast and slow pathways, primary pacemaking in the sinoatrial node, and subsidiary pacemaking in the slow pathway.
We implemented the asymmetry of coupling between model cells to obtain the direction-dependent conduction properties of the AVN, together with gradients of intercellular coupling and cell refractoriness. The AVN model demonstrates broad functionality, including normal sinus rhythm, AVN automaticity, filtering of high-rate atrial rhythms during atrial fibrillation and atrial flutter, direction-dependent properties, and realistic anterograde and retrograde conduction curves in the control case and the cases of fast and slow pathway ablation. In addition, the model is accompanied by a visualization of electrical conduction in the AVN, revealing the interaction between fast and slow pathways in the form of ladder diagrams. To show the validity of the proposed model, we compare the simulation results with the available experimental data.
The proposed model can be used both as a stand-alone module and as a part of complex 3D atrial or whole heart simulation systems. The results were published in the journal "Frontiers in Physiology" (impact factor 4.755), and the MATLAB source code was placed in a public repository.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
3: やや遅れている
理由
In the process of developing the cardiac conduction system model, we faced difficulties building a realistic model of the AVN since it is the most complex and puzzling part of the cardiac conduction system. We managed to create a compact mathematical AVN model for rabbit heart with a dual pathway structure using our recently developed model (PLOS One, 17(4): e0257935, 2022) for the pacemaking variant of the two-variable excitable Aliev-Panfilov cardiac cell model. Our model is multifunctional and realistically reproduces the behavior of the rabbit AVN observed in experiments. The model is computationally lightweight and provides multiple unique functions, such as retrograde conduction and coupling asymmetry, not available in any other AVN models. Pertinent MATLAB software was developed.
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| 今後の研究の推進方策 |
Using computer simulations with our model of the rabbit AVN, we will explore some cardiac system phenomena such as atrioventricular reentrant tachycardia (AVNRT) and Wenckebach periodicity. We will continue to enhance the model of the cardiac conduction system creating simple models for cardiac muscles able to produce ECG signals. We will study the difference in origin of "typical" (slow pathway - fast pathway) and "atypical" (fast pathway - slow pathway) types of AVNRT. Also, we will explore the appearance of different Wenckebach patterns and the role of secondary AV nodal pacemaker in the Wenckebach pattern formation. For this purpose, additional MATLAB software will be developed, and corresponding computer simulations will be performed.
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| 次年度使用額が生じた理由 |
With our developed rabbit AV node model, we will continue to build the full model cardiac conduction system. Meanwhile, we will study some cardiac system phenomena, such as atrioventricular reentrant tachycardia (AVNRT) and Wenckebach periodicity. We will spend the incurring amount for conference registration fees, open access publication fees in research journals and for computer hardware parts.
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