Total arterial compliance estimated by stroke volume-to-aortic pulse pressure ratio in humans

Abstract

On the basis of the windkessel model, the stroke volume-to-aortic pulse pressure ratio (SV/PP) has been proposed as an estimate of total arterial compliance, but recent studies have questioned this approximation. Aortic pressure was obtained at rest in 31 adults undergoing cardiac catheterization (47 ± 14 yr): controls ( n = 7), patients with dilated cardiomyopathy ( n = 10), and patients with other cardiac diseases ( n = 14). We calculated PP, mean aortic pressure (MAoP), heart period ( T), SV (thermodilution cardiac output/heart rate), total peripheral resistance ( R), total arterial compliance estimated by area method ( C area), and the time constant of aortic pressure decay in diastole ( RC area). In the overall population ( n = 31), there was no significant difference between SV/PP and C area. SV/PP was linearly related to C area (SV/PP = 0.99 C area + 0.05; r = 0.98; P < 0.001); the slope and intercept did not differ from unity and zero, respectively. Similar results were obtained in the three subgroups. These results implied that PP/MAoP and T/ RC areawere proportionally related ( T/ RC area= 1.18PP/MAoP − 0.07; r = 0.96; P < 0.001). We conclude that for humans at rest 1) SV/PP gave a reliable estimate of C area, and 2) T normalized by the time constant of aortic pressure decay in diastole was proportionally related to PP/MAoP. This last relationship could be considered an aspect of the coupling between the left ventricle and its load.

A comparison of methods for assessing total arterial compliance

“…6 Similarly, mean values here for AM correlate with those reported by O'Rourke et al 21 but not those reported by Liang et al 16 in similar patients. Values for SVPP observed in this study are higher than those reported by both Chemla et al and de Simone et al 12,22 This is presumably related to the method of measurement of SV. This lack of uniformity among measures of TAC between studies may be hard to interpret, however, most of these studies show the same differences within groups with and without risk.…”

“…It is not generally accepted as a calculation or estimation of C but rather an index of normal/abnormal compliance. 12 SV (LVOT CSA * LVOT VTI) and CO (SV * HR) were determined according to the ASE standard 13 and total vascular resistance was determined as mean arterial pressure MAP/CO (where LVOT ¼ left ventricular outflow tract; VTI ¼ velocity time integral; HR ¼ heart rate; MAP ¼ mean arterial pressure; CO ¼ cardiac output; SV ¼ stroke volume).…”

“…This lack of uniformity among measures of TAC between studies may be hard to interpret, however, most of these studies show the same differences within groups with and without risk. 5,12,16,22 Figure 1 Regression plots for total arterial compliance (TAC) (ml mm Hg -1 ) for the pulse-pressure method ((PPM) upper), area method ((AM) middle) and stroke volume/pulse-pressure method ((SVPP) bottom) between brachial (BPP) and aortic (AoPP) pulse pressure (mm Hg). The regression models were fit using an inverse model fit (Y ¼ b0 þ (b1/t)).…”

The effect of age on vascular compliance in man: which are the appropriate measures?

“…The reproducibility of all the measurements has been reported to be satisfactory. 12,15 With respect to sensitivity to disease processes Lehmann has discussed PWV and stated: 'The presence of advanced atherosclerosis has been correlated with the degree of aortic stiffening in animal studies, but not so far in human beings'. 16 However this is not true for measures of central aortic compliance 17,18 or magnetic resonance imaging methods.…”

“…This is termed SV/PP and has a good correlation between central compliance calculated using the area method. 12 …”