Multiphysics computational models for cardiac flow and virtual cardiography.

Area of Science:

• Multiphysics simulation
• Computational fluid dynamics
• Biomedical engineering

Background:

• Accurate prediction of intraventricular blood flow in pathological heart conditions is crucial for diagnosis.
• Current methods for cardiac flow analysis and sound generation lack comprehensive simulation capabilities.

Purpose of the Study:

• To develop a multiphysics simulation approach for predicting cardiac flows.
• To synthesize virtual echocardiography (ECHO) and phonocardiography (PC) signals from computational hemodynamic data.
• To investigate the relationship between cardiac disease and heart sounds, specifically systolic murmurs in hypertrophic cardiomyopathy.

Main Methods:

• Solving three-dimensional incompressible Navier-Stokes equations with an immersed boundary method for blood flow simulation.
• Synthesizing virtual ECHO signals using Lagrangian particle tracking and ultrasound wave scattering theory.
• Simulating virtual PC signals via a computational acoustics model for flow-induced sound generation and propagation ('hemoacoustics').

Main Results:

• Successfully reproduced color M-mode Doppler and continuous Doppler images for the left ventricle and outflow tract, validating against clinical data.
• Demonstrated the potential of virtual PC in modeling systolic murmurs caused by hypertrophic cardiomyopathy.
• Established a direct link between computational hemodynamics and observable acoustic signals.

Conclusions:

• The developed multiphysics simulation approach enables accurate prediction of cardiac flows and synthesis of virtual ECHO and PC signals.
• This virtual approach offers a powerful tool for understanding cardiac hemodynamics and diagnosing heart conditions.
• Virtual PC holds significant potential for novel insights into disease-specific heart sounds and their origins.