Longitudinal Changes of Input Impedance, Pulse Wave Velocity, and Wave Reflection in a Middle-Aged Population

The changes experienced by the arterial system due to the aging process have been extensively studied but are incompletely understood. Within-subject patterns of changes in regards to input impedance and wave reflection parameters have not been assessed. The Asklepios study is a longitudinal population study including healthy (at onset) middle-aged subjects, with 974 males and 1052 females undergoing 2 rounds of measurements of applanation tonometry and ultrasound, 10.15±1.40 years apart. Carotid-femoral pulse wave velocity, aortic input impedance, and wave reflection parameters were assessed, and linear mixed-effects models were used to evaluate their longitudinal trajectories and determinants. Overall, the effective 10-year increase in pulse wave velocity was less than expected from first round cross-sectional data, and pulse wave velocity was found to accelerate more in women than in men. Interestingly, the increase in pulse wave velocity was not paralleled by a decrease in arterial volume compliance, particularly in younger males. Aortic root characteristic impedance decreased with age in younger subjects while it increased for the older subjects in the study. These changes suggest that aortic dilation and elongation may play an important role determining the longitudinal age-related changes in impedance parameters in middle-age. Wave reflection decreased with aging, whereas resistance increased in women and decreased in men. We conclude that the effective impact of aging on arterial system properties, in a middle-aged population, is not well reflected by cross-sectional studies. Future studies should assess the interaction between geometric remodeling and wall stiffening as determinants of pulsatile hemodynamics.

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Noninvasive (Input) Impedance, Pulse Wave Velocity, and Wave Reflection in Healthy Middle-Aged Men and Women

Hypertension ◽

10.1161/hypertensionaha.106.085480 ◽

2007 ◽

Vol 49 (6) ◽

pp. 1248-1255 ◽

Cited By ~ 201

Author(s):

Patrick Segers ◽

Ernst R. Rietzschel ◽

Marc L. De Buyzere ◽

Sebastian J. Vermeersch ◽

Dirk De Bacquer ◽

...

Keyword(s):

Pulse Wave Velocity ◽

Wave Velocity ◽

Input Impedance ◽

Wave Reflection ◽

Pulse Wave ◽

Middle Aged ◽

Men And Women

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Assessment of Model Based (Input) Impedance, Pulse Wave Velocity, and Wave Reflection in the Asklepios Cohort

PLoS ONE ◽

10.1371/journal.pone.0141656 ◽

2015 ◽

Vol 10 (10) ◽

pp. e0141656 ◽

Cited By ~ 12

Author(s):

Bernhard Hametner ◽

Stephanie Parragh ◽

Christopher Mayer ◽

Thomas Weber ◽

Luc Van Bortel ◽

...

Keyword(s):

Pulse Wave Velocity ◽

Wave Velocity ◽

Input Impedance ◽

Wave Reflection ◽

Pulse Wave ◽

Model Based

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Maternal arterial stiffness in pregnancies affected by preeclampsia

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.01106.2008 ◽

2009 ◽

Vol 297 (2) ◽

pp. H759-H764 ◽

Cited By ~ 61

Author(s):

Christina Kaihura ◽

Makrina D. Savvidou ◽

James M. Anderson ◽

Carmel M. McEniery ◽

Kypros H. Nicolaides

Keyword(s):

Arterial Stiffness ◽

Pulse Wave Velocity ◽

Wave Velocity ◽

Wave Reflection ◽

Pulse Wave ◽

Augmentation Index ◽

Applanation Tonometry ◽

Control Group ◽

Arterial Tree ◽

Cross Sectional

Preeclampsia (PE) is characterized by an aberrant maternal cardiovascular adaptation to pregnancy and increased cardiovascular risk later on in life. The aim of this study was to compare the maternal wave reflections and arterial stiffness in women with established PE and those with normotensive pregnancies, after systematic adjustment for known confounders. This was a cross-sectional study involving 69 normotensive, pregnant women and 54 women with established PE. Maternal wave reflection (augmentation index) and pulse wave velocity of the carotid-radial and carotid-femoral parts of the arterial tree were assessed noninvasively using applanation tonometry. The measurements were adjusted for maternal age, heart rate, mean arterial pressure, and aortic time to wave reflection and expressed as multiples of the median (MoM) of the control group. In the PE group, compared with controls, there was an increase in the median pulse wave velocity of both the carotid to femoral [1.1, interquartile rage (IQR) 1.0–1.3 MoM vs. 0.9, IQR 0.9–1.0 MoM; P < 0.0001] and carotid to radial (1.0, IQR 0.9–1.1 MoM vs. 0.9, IQR 0.9–1.0 MoM; P = 0.01) parts of the arterial tree. In contrast, there were no significant differences between the two groups in the median augmentation index (0.9, IQR 0.7–1.1 MoM vs. 1.0, IQR 0.5–1.8 MoM; P = 0.46). In conclusion, we found that established PE is characterized by increased maternal arterial stiffness but not altered maternal wave reflection.

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Assessing the Accuracy of Non-Invasive Measuring Methods of Pulse Wave Velocity: An Analysis Based on Fluid-Structure Interaction Simulations in the Carotid Artery

ASME 2012 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2012-80160 ◽

2012 ◽

Author(s):

Abigail Swillens ◽

Liesbeth Taelman ◽

Joris Degroote ◽

Jan Vierendeels ◽

Patrick Segers

Keyword(s):

Pulse Wave Velocity ◽

Wave Velocity ◽

Pulse Wave ◽

Propagation Speed ◽

Original Method ◽

Arterial System ◽

Alternative Methods ◽

Cross Sectional ◽

Elastic Tubes ◽

Single Location

Pulse wave velocity (PWV) is the propagation speed of pressure and flow waves in the arterial system induced by the contracting left ventricle. PWV is a measure of arterial stiffness, and has been shown to predict cardiovascular events. In a clinical setting, PWV is usually associated with carotid-femoral PWV, reflecting the propagation speed over the aorta. It is, however, also possible to assess local PWV at a given measuring location, which reflects the stiffness of the artery under investigation at that particular location. When locally assessing PWV, single-location techniques are commonly used, which rely on the fact that in uniform elastic tubes, the relationship between a change in pressure (dP) and velocity (dU) is constant in the absence of wave reflections. As such, when plotting the pressure P as a function of the velocity U in an artery, a PU-loop is obtained, where reflection-free instants emerge as a straight line (typically during early systole), with a slope given by ρPWV (ρ = blood density). The original method relied on pressure and velocity data (PU-method), but alternative methods have been introduced based on cross-sectional area (A) and flow (Q) (QA-method), or diameter (D) and velocity (U) (ln(D)U-method).

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Aortic reflection coefficients and their association with global indexes of wave reflection in healthy controls and patients with Marfan's syndrome

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.01207.2005 ◽

2006 ◽

Vol 290 (6) ◽

pp. H2385-H2392 ◽

Cited By ~ 42

Author(s):

P. Segers ◽

J. De Backer ◽

D. Devos ◽

S. I. Rabben ◽

T. C. Gillebert ◽

...

Keyword(s):

Pulse Wave Velocity ◽

Wave Velocity ◽

Wave Reflection ◽

Pulse Wave ◽

Effective Length ◽

Arterial System ◽

Local Characteristic ◽

Reflection Coefficients ◽

Marfan’S Syndrome ◽

Marfan's Syndrome

Early return of reflected pressure waves increases the load on central arteries and may increase the risk of aortic rupture in patients with Marfan's syndrome (MFS). To assess whether wave reflection is elevated in MFS, we used ultrasound and MRI to measure central pressure and flow waveforms in 26 patients (13–54 yr of age) and 26 age- and gender-matched controls. Aortic systolic and diastolic cross-sectional areas were measured at the ascending and descending aorta (AA and DA), diaphragm (DIA), and lower abdominal aorta (AB). From these measurements, local characteristic impedance ( Z0- xx) and local reflection coefficients (Γ xx-yy) were calculated. Calculated global wave reflection indexes were the augmentation index (AIx) and the ratio of backward to forward pressure wave (Pb/Pf). The aorta was wider in MFS patients at AA ( P < 0.01) and DA ( P < 0.01). Aortic pulse wave velocity was 42 cm/s higher in MFS patients ( P < 0.05). Z0- xx was not different between groups, except at DA, where it was lower in MFS patients. In controls, ΓAA-DA was 0.31 ± 0.08, ΓDA-DIA was 0.00 ± 0.11, and ΓDIA-AB was 0.31 ± 0.16. Mean values of Γ xx-yy were not different between MFS patients and controls. In controls, aging diminished ΓAA-DA but increased ΓDIA-AB. Clear age-related patterns were absent in MFS patients. AIx or Pb/Pf was not higher in MFS patients than in controls. There were indications for enhanced wave reflection in young MFS patients. Our data demonstrated that the major determinants of AIx were pulse wave velocity and the effective length of the arterial system and, to a lesser degree, HR and Pb/Pf.

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Faculty Opinions recommendation of Normal vascular aging: differential effects on wave reflection and aortic pulse wave velocity: the Anglo-Cardiff Collaborative Trial (ACCT).

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.18358.475845 ◽

2006 ◽

Author(s):

Stanley Franklin

Keyword(s):

Pulse Wave Velocity ◽

Wave Velocity ◽

Wave Reflection ◽

Pulse Wave ◽

Aortic Pulse Wave Velocity ◽

Vascular Aging ◽

Differential Effects ◽

Collaborative Trial

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Association Between White Blood Cell Counts and Brachial-Ankle Pulse Wave Velocity in Chinese Hypertensive Adults: A Cross-Sectional Study

Angiology ◽

10.1177/00033197211021199 ◽

2021 ◽

pp. 000331972110211

Author(s):

Buyun Jia ◽

Chongfei Jiang ◽

Yun Song ◽

Chenfangyuan Duan ◽

Lishun Liu ◽

...

Keyword(s):

Arterial Stiffness ◽

Blood Cell ◽

Pulse Wave Velocity ◽

Wave Velocity ◽

White Blood Cell ◽

Pulse Wave ◽

Final Analysis ◽

Cross Sectional ◽

Cell Counts ◽

Wbc Count

Increased arterial stiffness is highly prevalent in patients with hypertension and is associated with cardiovascular (CV) risk. Increased white blood cell (WBC) counts may also be an independent risk factor for arterial stiffness and CV events. The aim of the study was to investigate the relationship between differential WBC counts and brachial-ankle pulse wave velocity (baPWV) in hypertensive adults. A total of 14 390 participants were included in the final analysis. A multivariate linear regression model was applied for the correlation analysis of WBC count and baPWV. Higher WBC counts were associated with a greater baPWV: adjusted β = 10 (95% CI, 8-13, P < .001). The same significant association was also found when WBC count was assessed as categories or quartiles. In addition, the effect of differential WBC subtypes, including neutrophil count and lymphocyte count on baPWV, showed the similar results. These findings showed that baPWV has positive associations with differential WBC counts in hypertensive adults.

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