 Vascular stiffness increases with aging, contributing to the increase in cardiac load. One important repercussion of such stiffening is an increase in pulse wave velocity. As the incident pressure wave generated by cardiac ejection encounters zones of impedance mismatch such as arterial bifurcations, part of the wave is reflected backward, summing with the incident wave, increasing central blood pressure CBP. With normal aging, hypertension, and heart failure, increased wave velocity causes the reflected wave to reach the heart earlier, in mid to late systole, considerably increasing late-systolic load, impairing cardiac ejection, and diastolic relaxation in the ensuing cardiac cycle. 