Functional mathematical model of dual pathway AV nodal conduction

Area of Science:

• Electrophysiology
• Computational Biology
• Cardiovascular Physiology

Background:

• Dual atrioventricular (AV) nodal pathways, fast pathway (FP) and slow pathway (SP), govern cardiac impulse propagation.
• Understanding their interaction is crucial for explaining complex heart rhythms and developing targeted therapies.

Purpose of the Study:

• To develop and validate a mathematical model of AV nodal conduction incorporating dual pathway physiology.
• To analyze the predictive capabilities of the model for AV conduction time and wave front interactions.

Main Methods:

• Development of a mathematical model using His electrogram alternance in rabbit atrial-AV nodal preparations.
• Analysis of model performance during regular and irregular atrial rhythms, including atrial fibrillation.
• Evaluation of AV node ablative modifications on conduction properties.

Main Results:

• The model accurately reproduced interactions between FP and SP wave fronts under various pacing conditions.
• High specificity and sensitivity (>85%) were achieved in predicting the responsible conduction pathway.
• Ablation of the SP significantly increased the HH interval during atrial fibrillation, unlike FP ablation.

Conclusions:

• The developed mathematical model enhances understanding of AV node mechanisms and dual pathway physiology.
• The model serves as a valuable tool for studying AV nodal conduction and its role in cardiac arrhythmias.
• Findings highlight the critical role of the SP in controlling ventricular rate during atrial fibrillation.