On estimating intraventricular hemodynamic forces from endocardial dynamics: A comparative study with 4D flow MRI

Area of Science:

• Cardiovascular Physiology
• Fluid Dynamics
• Medical Imaging

Background:

• Intraventricular pressure gradients and hemodynamic forces are crucial for ventricular function.
• Sub-optimal cardiac function may not be apparent through tissue motion alone.
• Current clinical cardiology lacks non-invasive tools to measure hemodynamic forces.

Purpose of the Study:

• To introduce a simplified fluid dynamics model for estimating hemodynamic forces.
• To enable hemodynamic force calculation without requiring the intraventricular velocity field.
• To validate the model's efficacy in clinical settings.

Main Methods:

• Developed a simplified fluid dynamics model based on first principles.
• Validated the model using 3D phase-contrast MRI (4D flow MRI) in 15 subjects.
• Reconstructed endocardial surfaces from standard long-axis projections for validation.

Main Results:

• The model provided consistent estimates for the base-apex hemodynamic component (r=0.77 instantaneous, r=0.88 RMS).
• Good estimates were achieved for the inferolateral-anteroseptal component (r=0.50 instantaneous, r=0.84 RMS).
• Model validation showed strong correlation with 4D flow MRI data.

Conclusions:

• The simplified model offers a physics-based approach to estimate hemodynamic forces.
• This method can integrate with existing MRI and echocardiography techniques.
• It holds potential for early detection of sub-clinical cardiac diseases and differentiating dysfunction.