scholarly journals Aortic pulse pressure homeostasis emerges from physiological adaptation of systemic arteries to local mechanical stresses

2016 ◽  
Vol 311 (3) ◽  
pp. R522-R531 ◽  
Author(s):  
Phuc H. Nguyen ◽  
Egemen Tuzun ◽  
Christopher M. Quick
Keyword(s):  
Pulse Pressure ◽  
Circumferential Stress ◽  
Mechanical Stresses ◽  
Arterial System ◽  
Physiological Adaptation ◽  
Adaptive Responses ◽  
Wall Stiffness ◽  
Blood Pressures ◽  
Standard Pulse ◽  
Systemic Arteries

Aortic pulse pressure arises from the interaction of the heart, the systemic arterial system, and peripheral microcirculations. The complex interaction between hemodynamics and arterial remodeling precludes the ability to experimentally ascribe changes in aortic pulse pressure to particular adaptive responses. Therefore, the purpose of the present work was to use a human systemic arterial system model to test the hypothesis that pulse pressure homeostasis can emerge from physiological adaptation of systemic arteries to local mechanical stresses. First, we assumed a systemic arterial system that had a realistic topology consisting of 121 arterial segments. Then the relationships of pulsatile blood pressures and flows in arterial segments were characterized by standard pulse transmission equations. Finally, each arterial segment was assumed to remodel to local stresses following three simple rules: 1) increases in endothelial shear stress increases radius, 2) increases in wall circumferential stress increases wall thickness, and 3) increases in wall circumferential stress decreases wall stiffness. Simulation of adaptation by iteratively calculating pulsatile hemodynamics, mechanical stresses, and vascular remodeling led to a general behavior in response to mechanical perturbations: initial increases in pulse pressure led to increased arterial compliances, and decreases in pulse pressure led to decreased compliances. Consequently, vascular adaptation returned pulse pressures back toward baseline conditions. This behavior manifested when modeling physiological adaptive responses to changes in cardiac output, changes in peripheral resistances, and changes in local arterial radii. The present work, thus, revealed that pulse pressure homeostasis emerges from physiological adaptation of systemic arteries to local mechanical stresses.

scholarly journals Peripheral Arterial Stiffness in Primary Aldosteronism

2012 ◽  
pp. 461-468 ◽  
Author(s):  
J. ROSA ◽  
Z. ŠOMLÓOVÁ ◽  
O. PETRÁK ◽  
B. ŠTRAUCH ◽  
T. INDRA ◽  
...  
Keyword(s):  
Arterial Stiffness ◽  
Primary Aldosteronism ◽  
Arterial System ◽  
Limited Data ◽  
Subsequent Increase ◽  
Wall Stiffness ◽  
Applanation Tonometer ◽  
Blood Pressures ◽  
Plasma Aldosterone Level ◽  
Peripheral Arterial

Aldosterone overproduction increases arterial wall stiffness by accumulation of different types of collagen fibres and growth factors. Our previous studies showed that central (aortic) arterial stiffness is increased in primary aldosteronism (PA) independently of concomitant hypertension and that these changes might be reversible after successful adrenalectomy. There is limited data available on the potential impact of mineralocorticoid overproduction on the deterioration of peripheral arterial stiffness. The current study was thus aimed at investigating the effect of aldosterone overproduction on peripheral arterial stiffness assessed by peripheral (femoral-ankle) pulse wave velocity (PWV) in PA patients compared with essential hypertension (EH) patients. Forty-nine patients with confirmed PA and 49 patients with EH were matched for age, blood pressure, body mass index, lipid profile, and fasting glucose. PWV was obtained using the Sphygmocor applanation tonometer. Both peripheral and central PWV were significantly higher in PA patients compared to EH patients, while clinical blood pressures were similar. Plasma aldosterone level was the main predictor of peripheral PWV in PA. Our data indicate aldosterone overproduction in PA does not preferentially affect central arterial system. Fibroproliferative effect of higher aldosterone levels lead to alteration of central-elastic as well as peripheral-muscular arteries with subsequent increase in its stiffness.

Empirical estimates of mean aortic pressure: advantages, drawbacks and implications for pressure redundancy

2002 ◽  
Vol 103 (1) ◽  
pp. 7-13 ◽  
Author(s):  
Denis CHEMLA ◽  
Jean-Louis HÉBERT ◽  
Eduardo APTECAR ◽  
Jean-Xavier MAZOIT ◽  
Karen ZAMANI ◽  
...  
Keyword(s):  
Form Factor ◽  
Pulse Pressure ◽  
Wave Reflection ◽  
Diastolic Pressure ◽  
Augmentation Index ◽  
Aortic Pressure ◽  
Arterial System ◽  
Wave Amplification ◽  
Empirical Estimates ◽  
Alternative Formula

Mean arterial pressure (MAP) is estimated at the brachial artery level by adding a fraction of pulse pressure (form factor; = 0.33) to diastolic pressure. We tested the hypothesis that a fixed form factor can also be used at the aortic root level. We recorded systolic aortic pressure (SAP) and diastolic aortic pressure (DAP), and we calculated aortic pulse pressure (PP) and the time-averaged MAP in the aorta of resting adults (n = 73; age 43±14 years). Wave reflection was quantified using the augmentation index. The aortic form factor (range 0.35-0.53) decreased with age, MAP, PP and augmentation index (each P<0.001). The mean form factor value (0.45) gave a reasonable estimation of MAP (MAP = DAP+0.45PP; bias = 0±2mmHg), and the bias increased with MAP (P<0.001). An alternative formula (MAP = DAP+PP/3+5mmHg) gave a more precise estimation (bias = 0±1mmHg), and the bias was not related to MAP. This latter formula was consistent with the previously reported mean pulse wave amplification of 15mmHg, and with unchanged MAP and diastolic pressure from aorta to periphery. Multiple linear regression showed that 99% of the variability of MAP was explained by the combined influence of DAP and SAP, thus confirming major pressure redundancy. Results were obtained irrespective of whether the marked differences in heart period and extent of wave reflection between subjects were taken into account. In conclusion, the aortic form factor was strongly influenced by age, aortic pressure and wave reflection. An empirical formula (MAP = DAP+PP/3+5mmHg) that is consistent with mechanical principles in the arterial system gave a more precise estimate of MAP in the aorta of resting humans. Only two distinct pressure-powered functions were carried out in the (SAP, DAP, MAP, PP) four-pressure set.

Intrinsic Vasomotion in the Dogfish Gill

1962 ◽  
Vol 39 (4) ◽  
pp. 503-512 ◽  
Author(s):  
G. H. SATCHELL
Keyword(s):  
Pressure Drop ◽  
Pulse Pressure ◽  
Sea Water ◽  
Squalus Acanthias ◽  
Circulatory Response ◽  
Aortic Blood ◽  
Blood Pressures

1. The circulatory response of anaesthetized curarized Squalus acanthias to anoxia of 2 min. duration is described. Anoxia was evoked either by perfusing the pharynx with deoxygenated sea water or by stopping the flow of normal sea water. 2. Ventral aortic blood pressures increased (systolic: 29.6-37.9 mm. Hg; mean: 24.1-27.1 mm. Hg) during a period of 2 min. Concurrently dorsal aortic blood pressures fell (systolic: 17.3-14.1 mm. Hg; mean: 16.3-12.4 mm. Hg). The heart slowed from 38 to 20 per min. The opacity of the gill, recorded with a phototransducer, decreased. 3. Comparison of simultaneous pulse traces from the dorsal and ventral aortae demonstrated that the pressure drop across the gills was increased during anoxia and decreased after it. 4. In some, but not all, experiments the dorsal aortic pulse pressure diminished as the ventral aortic pulse pressure increased. 5. Neither cutting all the branchial nerves nor atropinization completely abolished these responses. 6. Possible explanations of these findings are discussed; it is concluded that anoxia evoked a constriction of some prelamellar elements in the branchial vessels and that the response was, at least in part, intrinsic to the gill

Blood Pressure Parameters as Determinants of Small Artery Structure in Human Essential Hypertension

1997 ◽  
Vol 92 (6) ◽  
pp. 551-557 ◽  
Author(s):  
Anne Cooper ◽  
Anthony M. Heagerty
Keyword(s):  
Blood Pressure ◽  
Essential Hypertension ◽  
Pulse Pressure ◽  
Structural Parameters ◽  
Structural Parameter ◽  
Pressure Measurements ◽  
Significant Determinant ◽  
Small Artery ◽  
Small Arteries ◽  
Blood Pressures

1. Adaptive changes in small arteries may be more closely correlated with pulse pressure than with systolic, diastolic or mean blood pressures in human essential hypertension. 2. An analysis was performed on the structure of small arteries, age and blood pressure measurements obtained from 56 patients with untreated essential hypertension and 56 matched normotensive volunteers to examine the association between age, blood pressure and small artery structural parameters. 3. Essential hypertension was associated with an increase in media thickness and a decrease in lumen diameter, resulting in an increase in media/lumen ratio. 4. There was a significant correlation between age and media/lumen ratio in normotensive volunteers but not in patients with essential hypertension. 5. There was no correlation between any blood pressure and structural parameter in normotensive volunteers. 6. Both diastolic and mean blood pressures in essential hypertension correlated with media/lumen ratio (P < 0.01); systolic blood pressure correlated less well (P < 0.02). However, pulse pressure did not correlate with media/lumen ratio, suggesting that it is not a significant determinant of small artery structure in untreated essential hypertension.

ADAPTATION TO SUCROSE LOADING IN THE RAT

1966 ◽  
Vol 44 (3) ◽  
pp. 389-400
Author(s):  
Vincent Fiorica ◽  
P. F. Iampietro ◽  
Russell Moses
Keyword(s):  
Body Weight ◽  
Antidiuretic Hormone ◽  
Water Conservation ◽  
Physiological Adaptation ◽  
Loading Conditions ◽  
Adaptive Responses ◽  
Arterial Infusion ◽  
Initial Loading ◽  
Sucrose Solutions ◽  
Sucrose Loading

Four groups of unanesthetized rats were infused with standardized volumes of 1.46 M (50% w/v) sucrose solutions through chronically indwelling arterial catheters. The excretion of water and solutes was measured during the following 6 hours. Five days later, after the animals had returned to their pre-loading weights, each group was infused again with the same load given initially. After the second loading, a pattern of excretion of water and solutes was observed which was different from that elicited by the first loading. The adaptations manifested after a second loading were characterized principally by (a) a smaller total volume excretion of urine (milliliters per 100 g body weight), (b) the excretion of a smaller fraction of the infused load, (c) an earlier inhibition of the initial diuresis, and (d) the production of a more concentrated urine. It is suggested that the initial loading conditions generate a physiological adaptation which promotes the water conservation mechanisms of the animal. This may involve a greater sensitivity of the adapted animal to antidiuretic hormone. It was further observed that the characteristics of the adaptations generated by intra-arterial infusion are qualitatively different from those produced by intraperitoneal infusion. This suggests that the ability of hypertonic solutions to evoke adaptive responses is dependent on the route through which such solutions are given.

Estimation of Forearm Arterial Compliance in Essential Hypertension: A Preliminary Report

1982 ◽  
Vol 63 (s8) ◽  
pp. 87s-88s ◽  
Author(s):  
A. CH. Simon ◽  
J. A. Levenson ◽  
S. P. Laurent ◽  
M. E. Safar
Keyword(s):  
Blood Flow ◽  
Essential Hypertension ◽  
Brachial Artery ◽  
Diastolic Pressure ◽  
Arterial Compliance ◽  
Normal Subjects ◽  
Arterial System ◽  
Flow Measurements ◽  
Blood Pressures ◽  
Blood Flow Measurements

1. Simultaneous brachial artery pressure and blood flow measurements were made in 21 men, including six normal subjects and 15 patients with essential hypertension of the same age and diastolic pressure at the time of investigation. 2. Blood flow was evaluated by means of a pulsed Doppler device with a double transducer probe, enabling a precise evaluation of the calibre of the brachial artery. From analysis of the pressure-flow curves during diastole, forearm arterial compliance was estimated by using an original first-order model of the forearm arterial system. 3. Forearm arterial compliance was significantly decreased in hypertensive subjects. 4. Since patients and hypertensive subjects had similar blood pressures, the results indicate that the reduced forearm compliance was independent of blood pressure per se but may reflect in hypertensive subjects adaptive changes in the walls of peripheral large arteries.

scholarly journals Ankle Blood Pressure and Pulse Pressure as Predictors of Cerebrovascular Morbidity and Mortality in a Prospective Follow-Up Study

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Heikki J. Hietanen ◽  
Rauni Pääkkönen ◽  
Veikko Salomaa
Keyword(s):  
Blood Pressure ◽  
Pulse Pressure ◽  
Reference Group ◽  
Morbidity And Mortality ◽  
Abnormal Finding ◽  
Follow Up Study ◽  
Exercise Blood Pressure ◽  
Blood Pressures ◽  
Age And Sex

Background and Objective. We examined the association of elevated ankle blood pressure (ABP), together with exercise blood pressure, with incident cerebrovascular (CV) morbidity and mortality in a prospective follow-up study of 3,808 patients. The results were compared with pulse pressure, another indicator of arterial stiffness.Methods. Patients with normal ankle and exercise brachial blood pressures were taken as the reference group. Pulse pressure was considered as quartiles with the lowest quartile as the reference category.Results. A total of 170 subjects had a CV event during the follow-up. Multivariate adjusted hazard ratio of a CV event was 2.24 (95% CI 1.43–3.52, ) in patients with abnormal ABP. The pulse pressure was significant only in the model adjusted for age and sex.Conclusion. The risk of a future CV event was elevated already in those patients among whom elevated ABP was the only abnormal finding. As a risk marker, ABP is superior to the pulse pressure.

Histology and Biaxial Mechanical Behavior of Abdominal Aortic Aneurysm Tissue Samples

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Francesco Q. Pancheri ◽  
Robert A. Peattie ◽  
Nithin D. Reddy ◽  
Touhid Ahamed ◽  
Wenjian Lin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behavior ◽  
Circumferential Stress ◽  
Aortic Aneurysms ◽  
Smoking History ◽  
Tissue Samples ◽  
Abdominal Aortic ◽  
Wall Stiffness ◽  
Risk Of Rupture ◽  
Biaxial Tests

Abdominal aortic aneurysms (AAAs) represent permanent, localized dilations of the abdominal aorta that can be life-threatening if progressing to rupture. Evaluation of risk of rupture depends on understanding the mechanical behavior of patient AAA walls. In this project, a series of patient AAA wall tissue samples have been evaluated through a combined anamnestic, mechanical, and histopathologic approach. Mechanical properties of the samples have been characterized using a novel, strain-controlled, planar biaxial testing protocol emulating the in vivo deformation of the aorta. Histologically, the tissue ultrastructure was highly disrupted. All samples showed pronounced mechanical stiffening with stretch and were notably anisotropic, with greater stiffness in the circumferential than the axial direction. However, there were significant intrapatient variations in wall stiffness and stress. In biaxial tests in which the longitudinal stretch was held constant at 1.1 as the circumferential stretch was extended to 1.1, the maximum average circumferential stress was 330 ± 70 kPa, while the maximum average axial stress was 190 ± 30 kPa. A constitutive model considering the wall as anisotropic with two preferred directions fit the measured data well. No statistically significant differences in tissue mechanical properties were found based on patient gender, age, maximum bulge diameter, height, weight, body mass index, or smoking history. Although a larger patient cohort is merited to confirm these conclusions, the project provides new insight into the relationships between patient natural history, histopathology, and mechanical behavior that may be useful in the development of accurate methods for rupture risk evaluation.

scholarly journals Association between pulse pressure and progression of chronic kidney disease

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Toshiki Maeda ◽  
Soichiro Yokota ◽  
Takumi Nishi ◽  
Shunsuke Funakoshi ◽  
Masayoshi Tsuji ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Pulse Pressure ◽  
Predictive Marker ◽  
Population Based ◽  
Proportional Hazard ◽  
Ckd Progression ◽  
Blood Pressures ◽  
Incident Rate

AbstractThe aim of this study was to investigate the association between pulse pressure (PP) and chronic kidney disease (CKD) progression among the general population in Japan. We conducted a population-based cohort study of the residents of Iki Island, Nagasaki, Japan, from 2008 to 2018. We identified 1042 participants who had CKD (estimated glomerular filtration rate(eGFR) < 60 mL/min/1.73 m2 or the presence of proteinuria) at baseline. Cox’s proportional hazard model was used to evaluate the association between PP and progression of CKD. During a 4.66-year mean follow-up, there were 241 cases of CKD progression (incident rate: 49.8 per 1000 person-years). A significant increase existed in CKD progression per 10 mmHg of PP elevation, even when adjusted for confounding factors [adjusted hazard ratio 1.17 (1.06–1.29) p < 0.001]. Similar results were obtained even after dividing PP into quartiles [Q2: 1.14 (0.74–1.76), Q3: 1.35 (0.88–2.06), Q4: 1.87 (1.23–2.83) p = 0.003 for trend]. This trend did not change significantly irrespective of baseline systolic or diastolic blood pressures. PP remained a potential predictive marker, especially for eGFR decline. In conclusion, we found a significant association between PP and CKD progression. PP might be a potential predictive marker for CKD progression.

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