Title : Doppler ultrasound measurement of arterial stiffness
Abstract:
The stiffening of arteries has been widely recognized as a major contributor to cardiovascular diseases and all cause mortality. Arterial stiffening has significant association with arteriosclerosis and atherosclerosis development. In spite of the world-wide recognition, arterial stiffness is rarely measured in clinical practice. Arterial stiffness is currently measured primarily in pharmaceutical trials and research laboratories.
The most common index of arterial stiffness is pulse wave velocity which requires the measurement of the time for a pressure pulse to transit between two pressure sensors normally located on widely separated arteries. Existing measurement techniques require specialized pressure sensors and are applicable only to shallow arteries located close to the skin surface. Existing techniques are time consuming and provide only non-localized measures of over-all stiffness of multiple cascaded arteries.
In contrast, Doppler ultrasonography technology is regularly used in clinical practice to quickly measure blood flow velocity at arterial locations located significant distances below the skin surface. A flow velocity waveform, measured by Doppler ultrasound, provides a measure of the artery’s response to pulsatile flow, and quantifies the artery’s stiffness by the artery’s resonant frequency. Resonant frequency is applicable to a specific arterial location and is also directly related to the pulse wave velocity at the location. Resonant frequency is proposed here as a new index of arterial stiffness, one which has advantages over pulse wave velocity as currently measured. Resonant frequency can be measured quickly in clinical settings, and can measure stiffness in deep-set arteries at specific arterial locations.
Keywords: Arterial Compliance, Arterial Stiffness, Doppler Ultrasonography, Flow Velocity Waveform, Resonant Frequency.
