Relationship of effective arterial elastance to demographic and arterial characteristics in normotensive and hypertensive adults

OBJECTIVE: To evaluate demographic and vascular correlates of the effective arterial elastance noninvasively in normotensive and hypertensive adults. METHODS: In 202 subjects carotid ultrasonography and external arterial tonometry were simultaneously performed; carotid cross-sectional area, absolute and relative wall thicknesses, Peterson's and Young's elastic moduli and beta', a pressure-dependent index of arterial stiffness, were calculated. The impact of reflected waves on central pressure waveforms was evaluated by the 'augmentation index' (the relative increment in systolic pressure caused by the late-systolic peak). Left ventricular mass and relative wall thickness were assessed echocardiographically. The effective arterial elastance was estimated by dividing the pressure at the dicrotic notch by the Doppler-determined stroke index. RESULTS: The effective arterial elastance was higher in women among normotensives but similar between sexes among hypertensive subjects. It was correlated to age, mean blood pressure, body mass index and measures of arterial function, including Peterson's and Young's elastic moduli and beta', and to the augmentation index. It was also related to absolute and relative carotid wall thicknesses, lumen diameter and indexed cross-sectional area. Age, beta' and carotid cross-sectional area independently predicted effective arterial elastance in multiple regression analysis. CONCLUSIONS: Effective arterial elastance is related to demographic and arterial structural and functional characteristics. Increases in effective arterial elastance resulting from altered arterial structure and function may play a role in inducing left ventricular adaptative modifications.