Aortic compliance in human hypertension.

Abstract

Aortic compliance in normotensive and hypertensive Chinese subjects undergoing diagnostic cardiac catheterization was compared by using a newly described method that allows for determination of the pressure dependence of compliance if one assumes a value for the exponential coefficient of the pressure-volume relation of the large arteries. Under baseline conditions in the normotensive and hypertensive groups at mean aortic pressures of 963 and 128.6 mm Hg, aortic compliance averaged 1.47 and 0.80 ml/mm Hg, respectively. Compliance in the hypertensive group at a diastolic pressure of 99.4 mm Hg (which was nearly equal to the mean normotensive pressure) was 1.072 ml/mm Hg-still significantly lower than in the normotensive group. During nitroprusside infusion, however, the compliances in the hypertensive group increased to levels equal to or greater than those in the normotensive group. Thus, these data confirm that aortic compliance is lower in hypertensive than in normotensive humans. They further demonstrate that the lower compliance cannot be attributed entirely to the elevated blood pressure, suggesting that excess smooth muscle tone may be partly responsible. (Hypertension 1989;14:129-136) C ompliance is an important property of the arterial system. It is one measure of the properties of the walls of the vasculature, is a component of the load faced by the ventricle, and is a determinant of the configurations of the pressure and flow waves. Abnormalities in compliance can greatly affect cardiovascular function. For example, decreased compliance results in an increase in systolic and a decrease in diastolic aortic pressure-both of which are deleterious to the heart. The increased systolic pressure is an extra load during cardiac ejection and the decreased diastolic pressure can diminish coronary flow under certain conditions.There has been great interest in quantifying total arterial compliance.1 - 13 The accuracy of the values of compliance quoted in these studies is, however, questionable and has not been validated because it is extremely difficult to accurately measure the total arterial blood volume. In addition, compliance is a nonlinear function of pressure.

Risk Factors for Stiffness of the Wall of the Thoracic Aorta in Patients With Mild Atherosis.

“…6 Large conduit vessels such as the aorta appear to be particularly susceptible to blood pressure because of their continuous exposure to pulsatile pressure and shear stress. [1][2][3] In the present study, the aortic wall stiffness in the older group was significantly higher than that of the younger group. Although aortic plaque was more prevalent in the older group than in the younger group, the IMT in the aorta did not differ between the 2 groups.…”

Characteristics of resistant hypertension: ageing, body mass index, hyperaldosteronism, cardiac hypertrophy and vascular stiffness

“…28 Accordingly, the current data support the hypothesis that the progression from early stages of hypertension to severe and difficult to control hypertension is characterized by progressive large arterial rigidity and LVH. 29,30 Recognition of this progression is important clinically as it may allow indexing of vascular stiffness and LV mass to facilitate early identification of patients at risk of developing RHTN. If so, early intervention with effective lifestyle changes and appropriate pharmacological agents may slow or even prevent progression to development of RHTN.…”

Assessment of Arterial Stiffness Index as a Clinical Parameter for Atherosclerotic Coronary Artery Disease

“…Hypertension has also been well known as another cardiovascular risk factor, which might influence the arterial stiffness. 31 Diabetes has been reported to accelerate arterial stiffness, 32,33 whereas the roles of dyslipidemia and tobacco smoking are unclear. 34 In our study patients, the rates of hypertension and diabetes were slightly higher in patients with CAD, but these were not significantly different.…”