Computational Modeling and Analysis of Murmurs Generated by Modeled Aortic Stenoses.

Area of Science:

• Cardiovascular fluid dynamics
• Biomedical acoustics
• Computational biomechanics

Background:

• Aortic stenosis murmurs are critical diagnostic indicators.
• Accurate localization of murmur sources is clinically important.
• Previous studies established hemodynamic models of aortic stenosis.

Purpose of the Study:

• To investigate the generation and propagation of aortic stenosis murmurs using coupled simulations.
• To determine the murmur source location within the aorta.
• To assess the feasibility of predicting source location from surface sound signals.

Main Methods:

• Coupled hemodynamic-acoustic simulations of a stenosed aorta model.
• Modeling the thorax as a viscoelastic elliptic cylinder.
• Utilizing a high-order numerical method for acoustic simulations.
• Collecting sound signals from the simulated epidermal surface.

Main Results:

• The murmur source was identified at the proximal end of the aortic arch.
• Epidermal sound intensity patterns effectively predicted murmur source location.
• A discrepancy was observed between flow-derived and murmur-derived break frequencies.
• Inverse problem solving using Green's function also predicted source locations.

Conclusions:

• The study successfully localized the aortic stenosis murmur source through advanced simulations.
• Surface sound signal analysis shows promise for non-invasive clinical diagnosis.
• Findings offer insights into the physics of murmur generation and propagation.
• The results have direct implications for improving cardiac auscultation techniques.