Non-invasive evaluation of the conduit function and the buffering function of large arteries in man

Area of Science:

• Vascular Ultrasound
• Doppler Echocardiography
• Cardiovascular Physiology

Background:

• Non-invasive assessment of peripheral artery function is crucial for cardiovascular health monitoring.
• Existing methods may have limitations in accuracy or accessibility for measuring key hemodynamic parameters.
• Accurate measurement of arterial diameter, blood flow velocity, and pulse wave velocity is essential for evaluating vascular health.

Purpose of the Study:

• To validate a combined two-dimensional (2D) echography and range-gated Doppler system.
• To assess the non-invasive measurement capabilities for internal diameter, blood flow velocity, and pulse wave velocity in peripheral arteries (common carotid, femoral, brachial).
• To evaluate the system's accuracy in estimating blood flow and arterial compliance.

Main Methods:

• Utilized a 2D echography system coupled with a range-gated Doppler probe at a fixed angle (38°30').
• Visualized arteries using the echo-graphic probe to position the Doppler beam.
• Measured internal diameter and blood flow velocity using the range-gated Doppler system with the sample volume covering the internal diameter; validated velocity measurements against a hydraulic device (r = 0.98).

Main Results:

• Established normal values for diameter, blood flow velocity, and blood flow in 18 healthy volunteers for CCA, FA, and BA.
• Demonstrated high intra-observer (4.12–14.8%) and inter-observer (5.4–11.3%) reproducibility for diameter and velocity measurements.
• Simultaneous pulse wave velocity measurements allowed estimations of arterial distensibility, with accurate assessments of conduit and buffering functions for CCA and FA.

Conclusions:

• The coupled 2D echography and range-gated Doppler system provides a validated method for non-invasive measurement of peripheral artery diameter and blood flow velocity.
• The system accurately estimates blood flow (cross-sectional area × velocity) and arterial compliance (cross-sectional area / pulse wave velocity squared).
• The system is particularly accurate for evaluating the common carotid and femoral arteries, offering valuable insights into peripheral large artery function.