Mapping conduction velocity of early embryonic hearts with a robust fitting algorithm.

Area of Science:

• Developmental Biology
• Cardiovascular Physiology
• Biomedical Imaging

Background:

• Cardiac conduction maturation is crucial for heart development.
• Optical mapping is vital for electrophysiological signal measurement.
• Low signal-to-noise ratio (SNR) hinders early cardiac development conduction velocity measurements.

Purpose of the Study:

• To present a novel image processing approach for high-resolution, low-noise conduction velocity mapping in smaller tubular hearts.
• To overcome limitations of low SNR in action potential measurements during early cardiac development.

Main Methods:

• Utilized least squares optimizations for image processing.
• Fitted action potential traces to cumulative normal distribution functions.
• Employed 2D linear fitting for activation time gradient determination, adaptively adjusting window size.
• Corrected conduction velocity for 3D geometry using optical coherence tomography (OCT).

Main Results:

• The method demonstrated robustness in low SNR conditions (SNR = 2-5).
• An empirical equation was established to estimate maximum measurable conduction velocity.
• High-resolution conduction velocity maps of quail embryonic hearts were successfully generated.

Conclusions:

• The novel image processing approach enables accurate and high-resolution cardiac conduction velocity mapping in developing hearts.
• This method significantly improves SNR, facilitating precise electrophysiological measurements in challenging conditions.
• The findings contribute to a better understanding of cardiac development and electrophysiology.