Arterial path length estimation for heart-to-brachium pulse wave velocity.

Abstract

As an initial step to better define heart-brachial pulse wave velocity (hbPWV), a novel measure of proximal aortic stiffness, we proposed and validated a simple formula to estimate the arterial path length (Lhb) for hbPWV. In 190 patients aged 19-79 years, the reference Lhb was measured by a three-dimensional MRI. Using multiple regression analysis and fivefold cross-validation, estimation formulae were created using age, sex, and height. hbPWV was calculated as Lhb divided by the time interval from the second heart sound to the dicrotic notch on the brachial pressure wave. In a comparison of hbPWV calculated from MRI-based Lhb, strong correlations and accuracy were observed for the hbPWV obtained from the estimated Lhb by sex and height (r = 0.969, -0.05 ± 0.54 m per s of the mean difference), and even greater correlations and accuracy were observed for the estimated value by age, sex, and height (r = 0.976, 0.00 ± 0.43 m per s of the mean difference). hbPWV values obtained from the straight distance method and the height-based equation showed significant biases with mean differences of 2.64 ± 0.94 and 2.53 ± 0.94 m per s. hbPWV could be evaluated accurately by the simple equation to estimate Lhb.