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Figure 3 (A) Pressure volume loops and relations derived by preload reduction maneuver in a young and in an elderly patient. End systolic elastance (Ees) measures chamber systolic stiffness and is the slope of a line connecting the upper left-hand corners (end systole) from each pressure volume loop (dotted line). Arterial elastance (Ea) measures arterial load and stiffness and is depicted by the negative slope of the diagonal solid line shown in the figures. As noted in Figure 2, vascular stiffening was higher in the aged individual (Ea = 2.4 vs. 1.6 mm Hg/ml in these examples). This was accompanied by increases in ventricular stiffness (Ees = 3.6 vs. 2.1 mm Hg/ml, respectively). As a result, ventricular and vascular properties remained matched. (B) Group data showing positive correlation between ventricular systolic stiffness and arterial stiffness. See text for regression results. (C) Combined ventricular and vascular stiffening resulted in matching of the two systems (defined by the Ea/Ees ratio) that is independent of age. (D) Increased ventricular chamber systolic stiffness (Ees) also correlated with elevations in diastolic chamber stiffness (Ed). Both variables independently rise with age (data not shown).
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