Non-invasive technique for determining local pulse wave velocity in humans ascending aorta

Background: Pulse wave velocity (PWV) is a measure of arterial stiffness and widely used as a predictor of cardiovascular risk. Local PWV (lPWV) can be calculated non-invasively using the ln(D) U-loop method. Aim: To develop a novel non-invasive technique for the determination of lPWV in human ascending aorta. Methods: 13 healthy volunteers (19-33 years, 6 females) were studied using ultrasound (GE, Vivid E95) with a 1.5-4.5 MHz phased array transducer. M-mode in the parasternal long axis view was used for diameter measurements, Pulsed Wave Doppler ultrasound in the apical 5 chamber view was used for blood velocity measurements in the ascending aorta. Diameter and flow were measured sequentially. The ln(D) U-loop method was used to determine lPWV, and the SphygmoCor Xcel (AtCor Medical, Australia) was used to measure carotid-femoral PWV (cfPWV). Results: Mean lPWV using ln(D)U-loop was 3.6±0.7 m/s with higher values for men compared to women. The results showed that lPWV was systematically lower than cfPWV. Conclusions: lPWV can be measured non-invasively at the ascending aorta by ultrasound with sequential recordings of diameter and velocity using the ln(D)U-loop method.