Age related changes in the mechanics of the aorta and pulmonary artery of man

The effects of age on the mechanical properties of the ascending thoracic aorta and right pulmonary artery were studied angiographically in 43 patients during routine cardiac catheterization. The pressure strain elastic modulus (stiffness index Ep), and pulse wave velocity (c) of both structures were calculated and found to increase linearly with age, doubling between 20 and 60 yr. The regression equations are Ep = 90.0 + 16.0 X age and c = 3.0 + 0.10 X age for the ascending aorta, and Ep = 105.0 + 2.6 X age, and c = 2.2 + 0.02 X age for the right pulmonary artery. For modeling, therefore, both the right pulmonary artery and the aorta are large distension systems and can be described by linear regression equations.