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Impact of arterial elastance as a measure of vascular load on left ventricular geometry in hypertension
No full textObjective Effective arterial elastance (E-a), integrating the pulsatile component of left ventricular (LV) afterload, is an estimate of aortic input impedance. We evaluated relationships of E-a with left ventricular anatomy and function in essential hypertension, Design A cross-sectional analysis in 81 normotensive and 174 untreated hypertensive individuals enrolled in a referral hypertension centre, Methods Using echocardiography we determined left ventricular mass index (LVMI), relative wall thickness (RWT), stroke volume (SV), endocardial (FS,) and midwall (FS,) fractional shortening and total peripheral resistance (TPR), Carotid pressure waveforms were obtained by arterial tonometry, and end-systolic pressure (P-es) was measured at the dicrotic notch. E-a index (EaI) was calculated as P-es/(SV index); LV elastance (E-es) was estimated as P-es/LV end-systolic volume, and ventriculoarterial coupling was evaluated by the E-a/E-es ratio. Results EaI was higher in hypertensives than in normotensives (3.02 +/- 0.63 versus 2.40 +/- 0.52 mmHg/l per m(2); P< 0.0001). Using the 95% upper confidence limit in normotensives, hypertensives were divided in two groups with normal or elevated EaI. The 38 hypertensives with elevated EaI had higher RWT(0.41 +/- 0.06 versus 0.37 +/- 0.05), lower LVMI (87.5 +/- 18.5 versus 96.8 +/- 19.3 g/m(2)), higher TPR (2247 +/- 408 versus 1658 +/- 371 dynes/cm s(-5)) and lower FSe and FSm (35 +/- 5 versus 39 +/- 5 and 16 +/- 2 versus 18 +/- 2%; all P< 0.05) than patients with normal EaI. E-a/E-es ratio was increased and cardiac output was reduced in hypertensives with elevated Conclusions High values of EaI identify a minority of hypertensive patients characterized by elevated TPR, left ventricular concentric remodelling, depressed left ventricular systolic function and impaired ventriculoarterial coupling. J Hypertens 1999, 17:1007-1015 (C) Lippincott Williams & Wilkins
RELATIONSHIP OF EFFECTIVE ARTERIAL ELASTANCE TO DEMOGRAPHIC AND ARTERIAL CHARACTERISTICS IN NORMOTENSIVE AND HYPERTENSIVE ADULTS
No full textObjectives: 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 B', 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 arteria[ function, including Peterson's and Young's elastic moduli and B', and to the augmentation index. It was also related to absolute and relative carotid wall thicknesses, lumen diameter and indexed cross-sectional area. Age, B' 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
Relation of left ventricular midwall function to cardiovascular risk factors and arterial structure and function in normotensive and hypertensive adults.
No full textRelation of left ventricular midwall function to cardiovascular risk factors and arterial structure and function in normotensive and hypertensive adults.
No full textRELATION OF LEFT-VENTRICULAR HEMODYNAMIC LOAD AND CONTRACTILE PERFORMANCE TO LEFT-VENTRICULAR MASS IN HYPERTENSION
No full textImpact of arterial stiffening on left ventricular structure
No full textAging of the vasculature results in arterial stiffening and an increase in systolic and pulse pressures. Although pressure load is a stimulus for left ventricular hypertrophy, the extent to which vascular stiffening per se, independent of blood pressure, influences left ventricular structure is uncertain. Two hundred seventy-six subjects (79 normotensive and 197 otherwise healthy hypertensive individuals) underwent echocardiography to assess left ventricular structure. Arterial stiffness was estimated by the pressure-independent stiffness index, beta, and the pressure-dependent elastic modulus derived from simultaneous carotid ultrasound and applanation tonometry. Systemic arterial compliance (the inverse of stiffness) was estimated by the arterial compliance index. In multivariate analysis, beta was related to age (P, and the arterial compliance index are most strongly associated with aging and left ventricular concentric remodeling but not hypertrophy
Patterns of left ventricular hypertrophy and geometric remodeling in essential hypertension.
No full textThe spectrum of left ventricular geometric adaptation to hypertension was investigated in 165 patients with untreated essential hypertension and 125 age- and gender-matched normal adults studied by two-dimensional and M-mode echocardiography. Among hypertensive patients, left ventricular mass index and relative wall thickness were normal in 52%, whereas 13% had increased relative wall thickness with normal ventricular mass ("concentric remodeling"), 27% had increased mass with normal relative wall thickness (eccentric hypertrophy) and only 8% had "typical" hypertensive concentric hypertrophy (increase in both variables). Systemic hemodynamics paralleled ventricular geometry, with the highest peripheral resistance in the groups with concentric remodeling and hypertrophy, whereas cardiac index was super-normal in those with eccentric hypertrophy and low normal in patients with concentric remodeling. The left ventricular short-axis/long-axis ratio was positively related to stroke volume (r = 0.45, p less than 0.001), with cavity shape most elliptic in patients with concentric remodeling and most spheric in those with eccentric hypertrophy. Normality of left ventricular mass in concentric remodeling appeared to reflect offsetting by volume "underload" of the effects of pressure overload, whereas eccentric hypertrophy was associated with concomitant pressure and volume overload. Thus, arterial hypertension is associated with a spectrum of cardiac geometric adaptation matched to systemic hemodynamics and ventricular load. Concentric left ventricular remodeling and eccentric hypertrophy are more common than the typical pattern of concentric hypertrophy in untreated hypertensive patients
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