Semi-automated shear stress measurements in developing embryonic hearts

Area of Science:

• Cardiovascular Science
• Developmental Biology
• Biomedical Engineering

Background:

• Blood shear stress is crucial for cardiac development and gene expression.
• Abnormal shear stress in early heart development can cause congenital heart defects.
• Current methods for shear stress measurement are computationally intensive and impractical for large studies.

Purpose of the Study:

• To develop a more practical and computationally efficient method for estimating blood shear stress.
• To facilitate the inclusion of shear stress measurements in longitudinal studies of cardiac development.
• To improve understanding of the mechanisms underlying congenital heart defects.

Main Methods:

• Utilized two adjacent optical coherence tomography (OCT) frames (B-scans).
• Determined lumen geometry and flow direction from structural OCT data.
• Measured blood velocity using Doppler OCT signals to estimate shear stress.

Main Results:

• The new shear stress estimation method was validated using flow phantom experiments.
• The approach was successfully applied to live quail embryo hearts.
• Observed shear stress patterns in quail embryos were consistent with previous findings.

Conclusions:

• The developed method provides a practical and efficient way to estimate blood shear stress.
• This technique can be integrated into longitudinal studies to investigate cardiac development and congenital heart defects.
• The findings support the role of shear stress in normal and abnormal cardiac morphogenesis.