Determinants of Elevated Pulse Pressure in Middle-Aged and Older Subjects With Uncomplicated Systolic Hypertension

Abstract

Background-Elevated pulse pressure (PP) is associated with increased cardiovascular risk and is thought to be secondary to elastin fragmentation with secondary collagen deposition and stiffening of the aortic wall, leading to a dilated, noncompliant vasculature. Methods and Results-By use of calibrated tonometry and pulsed Doppler, arterial stiffness and pulsatile hemodynamics were assessed in 128 subjects with uncomplicated systolic hypertension (supine systolic pressure Ն140 mm Hg off medication) and 30 normotensive control subjects of comparable age and gender. Pulse-wave velocity was assessed from tonometry and body surface measurements. Characteristic impedance (Z c ) was calculated from the ratio of change in carotid pressure and aortic flow in early systole. Effective aortic diameter was assessed by use of the water hammer equation. Hypertensives were heavier (PϽ0.001) and had higher PP (PϽ0.001), which was attributable primarily to higher Z c (PϽ0.001), especially in women. Pulse-wave velocity was higher in hypertensives (Pϭ0.001); however, this difference was not significant after adjustment for differences in mean arterial pressure (MAP) (PϾ0.153), whereas increased Z c remained highly significant (PϽ0.001). Increased Z c in women and in hypertensive men was attributable to decreased effective aortic diameter, with no difference in wall stiffness at comparable MAP and body weight. Conclusions-Elevated PP in systolic hypertension was independent of MAP and was attributable primarily to elevated Z c and reduced effective diameter of the proximal aorta. These findings are not consistent with the hypothesis of secondary aortic degeneration, dilation, and wall stiffening but rather suggest that aortic function may play an active role in the pathophysiology of systolic hypertension.

Relations Between Aortic Stiffness and Left Ventricular Mechanical Function in the Community

“…In light of these prior results, the lack of association of CFPWV with circumferential strain is consistent with the concept that mechanical (ie, non‐hemodynamic) coupling is selectively related to LV function in the long axis. Zc was associated with both GLS and GCS, which may be related to the strong association between Zc and pressure pulsatility,62 possibly contributing to a secondary association between pressure pulsatility (which imposes an omnidirectional load) and global LV load that includes GCS 64. Additional research is needed to investigate differences in relations of CFPWV and Zc with LV function.…”

Proximal Aortic Diameter and Aortic Pressure-Flow Relationship in Systolic Hypertension

“…They further propose that drugs such as omapatrilat can reduce aortic stiffness directly and thereby provide effective treatment of systolic hypertension. 1,2 The prevailing view is that systolic hypertension is largely due to early return of wave reflection, is associated with degeneration and dilation of the proximal aorta, and is best treated by reduction in peripheral wave reflection by vasodilator drugs. 3,4 The authors did not provide measured aortic diameter or aortic pressure/flow relationships, yet they referred to both in the title of their article.…”

Association between ankle blood pressure and central arterial wave reflection

“…1 Although there is still an ongoing controversy as to the amount of relative contributions that incident and reflection waves make to central aortic systolic BP, one prevailing view supported by epidemiological and pharmacological studies suggests that arterial wave reflection is a primary mechanism responsible for elevated central systolic BP. 5,[16][17][18] Furthermore, because of the considerable degree of arterial branching and structural changes, the lower body is believed to be the important site of wave reflection and impedance mismatch. 6,7 Therefore, the finding from this study that lower limb vascular resistance, as estimated by the MAP from ankle, is a stronger contributor to the phenomenon of arterial wave reflection than brachial BP is consistent with the current understanding of haemodynamics.…”

“…6,7 Therefore, the finding from this study that lower limb vascular resistance, as estimated by the MAP from ankle, is a stronger contributor to the phenomenon of arterial wave reflection than brachial BP is consistent with the current understanding of haemodynamics. It should be noted, however, that reduced aortic diameter 16 as well as the aortic reservoir (capacitative properties) 19 may also have a role in augmenting central arterial wave reflection.…”