A mathematical model of aortic valve vibration

Area of Science:

• Cardiovascular Physiology
• Biomedical Engineering
• Fluid Dynamics

Background:

• The second heart sound (S2) is experimentally linked to diastolic vibrations of the closed aortic valve.
• Understanding the mechanics of S2 generation is crucial for diagnosing cardiac conditions.

Purpose of the Study:

• To develop a first-principles mathematical model of aortic valve vibrations during the second heart sound.
• To validate the model's predictions against patient data and identify key influencing factors.

Main Methods:

• Developed a one-dimensional, non-linear fluid behavior model.
• Incorporated a non-linear, planar valve model, creating a coupled system.
• Utilized the method of characteristics in finite difference form for solution.

Main Results:

• The model's predicted valve frequency and amplitude closely matched patient data.
• Demonstrated a strong dependency of the valve's response on the forcing function and stiffness.
• Identified a weaker dependency of the response on valve mass.

Conclusions:

• The developed mathematical model provides a robust framework for understanding S2 generation.
• Aortic valve stiffness and the forcing function are critical determinants of S2 characteristics.
• This model can aid in the non-invasive assessment of aortic valve dynamics.