Aortic Pulse Pressure Research Articles

Energetically wasteful wave reflections due to impedance mismatching in hypertension and their reversal with vasodilator: Time and frequency domain evaluations

BackgroundIncreased pulse wave reflections in hypertension arise due to impedance mismatching and the effective energy transmission to the vasculature is compromised. Their quantification in the time and the frequency domains are compared and the beneficial effect of vasodilator is evaluated in the study. MethodsA simple, fast time domain method for the resolution of aortic pressure and flow pulses into their forward and reflected components is presented, together with frequency domain reflection coefficient and impedance calculations. Both steady and pulsatile energy components are quantified during induced hypertension (HBP) and subsequent vasodilator (VSD, nitroprusside) treatment in experimental mongrel dogs. Corresponding power generation and usage are also analyzed. ResultsCharacteristic impedance and peripheral resistance were not statistically different between the methods (p > 0.05). Time domain reflection coefficient identified significant differences among control, HBP and VSD groups (p < 0.05) while the frequency domain method did not adequately differentiate the control and the HBP groups. Impedance calculations were similar between the two methods. Frequency domain calculations of total, mean and pulsatile power were, on average, 32.6 mW higher, 12.8 mW lower and 45.4 mW higher than their respective time domain calculations (p < 0.05). Hypertension increased energy consumption, on average, by 88.8 mJ (p < 0.05) and subsequent VSD decreased the energy consumption, on average, by 99.4 mJ (p < 0.05). ConclusionImpedance mismatching in hypertension which leads to increased wave reflections and significantly increased pulsatile work, could be effectively alleviated through vasodilator therapy. This can be quantified through the time-domain method, which is fast and equally accurate as the time-consuming frequency domain approach. The time domain method to quantify crucial parameters such as stroke work cannot be readily determined using the frequency domain methods.

Abstract 16664: Intrapatient Variability in the Brockenbrough-Braunwald-Morrow Sign and Peak Instantaneous Left Ventricular Outflow Gradients in Obstructive Hypertrophic Cardiomyopathy

Introduction: Although the variability in left ventricular outflow tract (LVOT) gradients in patients with hypertrophic cardiomyopathy (HCM) is well known, the value of pulse pressure (PP) changes with ectopy for predicting changes in LVOT gradient remains unreported. Hypothesis: This study examines the intrapatient variability in peak instantaneous LVOT gradients and aortic pulse pressure (PP) associated with the Brockenbrough-Braunwald-Morrow sign (BBM sign) compared with beat-to-beat variability. Methods: Variability in continuously recorded, high-fidelity left ventricular and aortic pressure waveforms were evaluated by computer-aided analysis in the resting state (N = 659 beats) and during supine exercise (N = 379 beats) in a symptomatic patient with a resting LVOT gradient &gt;30 mmHg. Results: BBM sign was observed in 92.9% (26/28) of post-PVC beats at rest and the post PVC PP decreased 11.8±8.2% (P&lt;0.001) compared with a 148.3±49.5% (P&lt;0.001) increase in the LVOT gradient. During exercise, BBM sign was noted in 84.2% (32/38) of post-PVCs beats and PP decreased 4.0±6.3% (P&lt;0.001) compared with a 74.2±37.5% (P&lt;0.001) increase in LVOT gradient. PP decreases were also noted in 89.5% (17/19) beats during sinus arrhythmia following prolonged RR intervals. Changes in pulse pressure with ectopy poorly predicted quantitative changes in the LVOT gradient (R 2 ≤ 0.198). However, component analysis of the LVOT gradient suggests that beat-to-beat variability provides information similar to ectopic provocation in characterizing gradients in HCM and that rest and exercise changes converge to a common reference value. Conclusions: Although caution is suggested when interpreting pulse pressure changes with the BBM sign as surrogate for measuring LVOT gradients, this study suggests that analysis of hemodynamic variability in HCM may prove useful in characterizing the severity of obstruction.

Functional recovery after dantrolene-supplementation of cold stored hearts using an ex vivo isolated working rat heart model.

The ryanodine receptor antagonist dantrolene inhibits calcium release from the sarcoplasmic reticulum and reduces cardiac ischaemia-reperfusion injury (IRI) in global warm ischaemia models however the cardioprotective potential of dantrolene under hypothermic conditions is unknown. This study addresses whether the addition of dantrolene during cardioplegia and hypothermic storage of the donor heart can improve functional recovery and reduce IRI. Using an ex vivo isolated working heart model, Wistar rat (3 month and 12 month) hearts were perfused to acquire baseline haemodynamic measurements of aortic flow, coronary flow, cardiac output, pulse pressure and heart rate. Hearts were arrested and stored in Celsior preservation solution supplemented with 0.2–40 μM dantrolene for 6 hours at 4°C, then reperfused (15 min Langendorff, 30 min working mode). In 3-month hearts, supplementation with 1 μM dantrolene significantly improved aortic flow and cardiac output compared to unsupplemented controls however lactate dehydrogenase (LDH) release and contraction bands were comparable. In contrast, 40 μM dantrolene-supplementation yielded poor cardiac recovery, increased post-reperfusion LDH but reduced contraction bands. All 3-month hearts stored in dantrolene displayed significantly reduced cleaved-caspase 3 intensities compared to controls. Analysis of cardioprotective signalling pathways showed no changes in AMPKα however dantrolene increased STAT3 and ERK1/2 signaling in a manner unrelated to functional recovery and AKT activity was reduced in 1 μM dantrolene-stored hearts. In contrast to 3-month hearts, no significant improvements were observed in the functional recovery of 12-month hearts following prolonged storage in 1 μM dantrolene. Conclusions: Dantrolene supplementation at 1 μM during hypothermic heart preservation improved functional recovery of young, but not older (12 month) hearts. Although the molecular mechanisms responsible for dantrolene-mediated cardioprotection are unclear, our studies show no correlation between improved functional recovery and SAFE and RISK pathway activation.

A17747 Changes in Parameters of Arterial Stiffness with Posture in Hypertensive patients with and without Anti-Hypertensive treatment

Objectives: To determine and compare differences in postural variation for arterial stiffness between hypertensive patients with and without medication Methods: Postural variations of parameters of arterial stiffness are measured in hypertensive patients with medication (41 subjects) and without medication (15 subjects). Operator index, central aortic systolic pressure (ASP), central aortic pulse pressure (APP), Augmentation Index (AI) and brachial systolic pressure (SP) and brachial diastolic pressure (DP) were measured in supine and sitting positions. Hypertensive subjects were chosen based on their ambulatory blood pressure monitoring and had brachial blood pressure above 140/90 mmHg on at least two separate occasions in clinic. The BP characteristics were obtained through SphygmoCor device between 8am to 10am on supine position. After three minutes, values in sitting position were obtained. Informed verbal consent was obtained from all participants and ethics approval was taken before the start of the study. Differences between BP characteristics in supine and sitting were compared using non-parametric paired test of Wilcoxon Signed-rank test. Differences in BP characteristics amongst the different groups of subjects were analysed using Man Whitney U test. A p < 0.05 was accepted as statistically significant in both tests Results: Statistically significant decrement in APP (38 (35–54 vs 38 (31–48), p = 0.0058) and significant increment in DP (74 (69–83) vs 76 (69–87), p = 0.023) was observed in hypertensive subjects. (Table 1) Conclusion: Postural variation had an effect on APP and DP in hypertensive subjects on anti-hypertensive medications but no effect in subjects off medications. While a postural variations of AI were noted on medications compared to subjects off medication, this was not statistically significant

A6509 The Obesity Paradox

Objectives: A clue to the “Obesity Paradox” is that patients at the upper extreme of body mass and blood pressure often have youthful arterial pressure waveforms that show optimally-timed wave reflection in the proximal aorta and left ventricle. Central obesity may compress the aorta and conduit arteries in the abdomen, thus decreasing aortic stiffness and delaying return of wave reflection to the heart. Methods: Central aortic pressure waves and indices of wave reflection on the aortic pressure wave were generated from radial tonometry and calibrated to brachial cuff pressures (SphygmoCor, AtCor Medical, Sydney, Australia). Data recorded from 101 patients attending a cardiovascular outpatient clinic at Ruijin Hospital North, Shanghai (table). Subjects were divided into 3 groups according to their Body Mass Index (BMI < = 24 normal, 24–28 overweight, > = 28 obese; for Chinese population). Results: Brachial and aortic pressure values including Systolic (SP), Diastolic (DP), Pulse Pressure (PP), and carotid-femoral pulse wave velocity did not differ significantly between normal and overweight/obese group. Aortic SP and aortic PP were lower for the overweight/obese group than normal, while aortic DP was higher. Despite no difference in standard pressure measurement, there were significant changes (p < 0.05) in indices of aortic pressure wave reflection between normal and overweight/obese groups. Augmented Pressure, Augmentation Index, and pressure amplification (calculated as aortic SP ÷ brachial SP) decreased progressively as BMI increased. Conclusion: The Obesity Paradox, presently unexplained, is likely due to reduced central pressure wave reflection in overweight and obese persons. This study is continuing; the results may explain the obesity paradox in terms of arterial wave travel and reflection.

EP13.02: Non‐invasive measurement of fetal aortic pulse pressure using ultrasound‐phased tracking method: an investigation using a fetal sheep model

EP13.02: Non‐invasive measurement of fetal aortic pulse pressure using ultrasound‐phased tracking method: an investigation using a fetal sheep model

Cardiovascular and Metabolic Health of 74 Children From Women Previously Diagnosed With Polycystic Ovary Syndrome in Comparison With a Population-Based Reference Cohort.

Women with polycystic ovary syndrome (PCOS) have compromised cardiovascular health profiles and an increased risk of pregnancy complications. In order to evaluate potential consequences, we aim to compare the cardiovascular and metabolic health of the children from women with PCOS with a population-based reference cohort. We included children from women with PCOS between the age of 2.5 to 4 years (n = 42) and 6 to 8 years (n = 32). The reference groups consisted of 168 (3-4 years old) and 130 children (7-8 years old). In an extensive cardiovascular screening program, we measured anthropometrics and blood pressure (all children), heart function and vascular rigidity (young children), metabolic laboratory assessment and carotid intima thickness (old age-group). Results showed that young PCOS offspring have a significantly lower diastolic blood pressure (β = 2.3 [95% confidence interval, CI: 0.5-4.0]) and higher aortic pulse pressure (β = -1.4 [95% CI: -2.5 to -0.2]), compared to the reference population. Furthermore, a higher left ventricle internal diameter but a lower tissue Doppler imaging of the right wall in systole compared to the reference group was found. Older offspring of women with PCOS presented with a significantly lower breast and abdominal circumference, but higher triglycerides (β = -0.1 [95% CI: -0.2 to -0.1]), LDL-cholesterol (β = -0.4 [95% CI: -0.6 to -0.1]), and higher carotid intima-media thickness (β = -31.7 [95% CI: -46.6 to -16.9]) compared to the reference group. In conclusion, we observe subtle but distinct cardiovascular and metabolic abnormalities already at an early age in PCOS offspring compared to a population-based reference group, despite a lower diastolic blood pressure, breast, and abdominal circumference. These preliminary findings require confirmation in independent data sets.

Aortic stiffness, central pulse pressure and cognitive function following acute resistance exercise.

While resistance exercise (RE) is known to be beneficial for overall health, one bout of RE acutely increases aortic stiffness and pulse pressure (PP). Increases in aortic stiffness and PP in a setting of aging has been shown to detrimentally impact cognitive function. This study examined whether increased aortic stiffness and PP from an acute bout of RE is associated with cognitive function. Thirty-five participants (21 ± 2years) underwent cognitive testing before and after either an acute bout of RE or a non-exercise time-control condition. Cognitive function was assessed as reaction time and accuracy during memory recognition, attention (Flanker) and working memory (N-back) tasks. Aortic stiffness and PP were measured via pulse wave velocity (PWV) and pulse wave analysis, respectively, using a brachial oscillometric device. There were significant increases in aortic PWV and aortic PP following RE (p < 0.05) with no change in PWV or PP following the non-exercise control condition (p > 0.05). There was no change in accuracy metrics (% hits) across conditions for any cognitive task (p > 0.05). There was a condition-by-time interaction for reaction time for the memory task (p < 0.05) driven by a significant decrease in reaction times following RE (p < 0.05) with no change in reaction time following the non-exercise control (p > 0.05). Functional increases in aortic stiffness and pulse pressure following acute RE occur in the absence of detrimental changes in cognitive function in young, healthy adults.

Association between diet and measures of arterial stiffness in type 1 diabetes – Focus on dietary patterns and macronutrient substitutions

Background and aimsIncreased arterial stiffness contributes to diabetic vascular complications. We identified dietary factors related to arterial stiffness in individuals with type 1 diabetes, a population with high risk of cardiovascular disease. Methods and resultsAltogether, 612 participants (40% men, mean ± standard deviation age 45 ± 13 years) completed a validated diet questionnaire and underwent measurements of arterial stiffness. Of these, 470 additionally completed a food record. Exploratory factor analysis was applied to identify dietary patterns from the diet questionnaires, and nutrient intakes were calculated from food record entries. Arterial stiffness was measured by applanation tonometry. Of the seven dietary factors formed, the factor scores of “Full-fat cheese and eggs” and “Sweet” patterns were negatively associated with measures of arterial stiffness. In the multivariable macronutrient substitution models, favouring carbohydrates over fats was associated with higher aortic mean arterial pressure and aortic pulse wave velocity. When carbohydrates were consumed in place of proteins, higher aortic pulse pressure, aortic mean arterial pressure, and augmentation index were recorded. Replacing energy from alcohol with proteins, was associated with lower aortic pulse pressure, aortic mean arterial pressure, and augmentation index. Relative distributions of dietary fatty acids were neutral with respect to the measures of arterial stiffness. ConclusionThe macronutrient distribution of the diet is likely to affect the resilience of the arteries. Our observations suggest that reducing energy intake from carbohydrates and alcohol may be beneficial. These observations, especially those dealing with dietary patterns, need to be confirmed in a longitudinal study.

Arterial damage and cognitive decline in chronic kidney disease patients.

In the general population aortic stiffening, assessed by carotid femoral pulse wave velocity (cf-PWV), is associated with cognitive dysfunction (CO/DY). Data in chronic kidney disease (CKD) are limited. This study tests the hypothesis that large artery stiffness and microvascular damage in CKD patients are related to the damage of brain microcirculation reflected by impaired cognitive function. A cross-sectional study enrolled 151 patients (mean age 58.4years; 64.5% males; 44 patients with CKD stage 1; 47 with stage 2; 25 with stage 3; and 35 with stage 4). Cognitive impairment, assessed by the Mini Mental State Examination (MMSE), the Clock - drawing test (Clock-test), and the Instrumental Activity of Daily Living (IADL), was considered as primary outcome. We measured systolic and pulse pressures at the brachial and aortic sites and cf-PWV. Our patients revealed a significant linear deterioration in all the domains of cognitive function according to CKD stages. High values of cf-PWV (P=0.029) and aortic pulse pressure (aPP) (P<0.026) were independent determinants of cognitive decline assessed by the MMSE. The present trial supports the hypothesis of an interaction between the kidney, large artery damage, central pressure pulsatility, and the injury of brain microcirculation. In clinical practice, cf-PWV and aPP measurements may help to predict cognitive decline. Whether the reduction in aortic stiffness following an aggressive treatment translates into improved cognitive outcomes remains to be determined.

Postexercise hypotension in central aortic pressures following walking and its relation to cardiorespiratory fitness.

Central aortic blood pressure (BP) is reduced after exercise. The aim of this study was to determine whether cardiorespiratory fitness relates to postexercise reductions in aortic BP. Sixteen young adults completed maximal exercise testing for peak oxygen uptake (VO2). Participants walked at a slow (80 steps/min, ~47% maxHR) and fast (125 steps/min, ~65% maxHR) stepping cadence for 3000 steps on two nonconsecutive days. Before and after each walking condition, radial tonometry was used to derive aortic pressures. Measurements after walking were taken after 30 and 60 min of supine recovery. The change in aortic BP was similar between walking cadences. Aortic systolic BP (-2.3 mmHg, P=0.03) and pulse pressure (-3.2 mmHg, P<0.001) were significantly reduced after 60 min of recovery as compared to baseline. The reduction in aortic pulse pressure was associated with decreased forward (r=0.69, P<0.001) and backward wave pressure (r=0.70, P<0.001). Peak VO2 was not associated (P>0.05) with these changes, but was strongly associated with non-significant changes in aortic systolic BP (30min: r=-0.54, P=0.03) and diastolic BP (30 min: r=-0.64, 60 min: r=-0.77; both P<0.01) after slow walking only. These results indicate that cardiorespiratory fitness associates with aortic pressure reductions after walking dependent on exercise intensity.

Higher Aortic Stiffness Is Associated With Lower Global Cerebrovascular Reserve Among Older Humans.

Greater aortic stiffness and pulse pressure are associated with cerebrovascular remodeling, reduced white matter microstructure, and cognitive performance with aging in humans. However, it is unclear whether aortic stiffness and pulse pressure are associated with reduced basal global cerebral blood flow (CBF) and cerebrovascular reserve among older adults. Global CBF was quantified in 205 adults (range, 19-87 years; mean±SE: 30.6±1.3 years) using quantitative [15O]water brain positron emission tomography imaging. In a subset of older adults (n=24; 70.0±2.0 years), aortic stiffness (carotid femoral pulse wave velocity) and cerebrovascular reserve (change in global CBF after intravenous infusion of acetazolamide) were assessed. In the entire cohort, global CBF was lower in older compared with young adults (36.5±1.1 versus 50.5±0.7 mL/min per 100 mL; P<0.001). Global CBF was higher in young women compared with young men (51.0±0.30 versus 47.4±0.03 mL/min per 100 mL; P<0.001) but did not differ between older women and men (P=0.63). In older adults, greater carotid femoral pulse wave velocity was associated with lower cerebrovascular reserve (r=-0.68; P=0.001 adjusted for age, sex, and mean arterial pressure) but not global CBF (r=0.13; P=0.60). Brachial pulse pressure was not associated with lower cerebrovascular reserve (r=-0.37; P=0.159) when adjusted for age and sex. These data indicate that the age-related increases in aortic stiffness may contribute, in part, to the brain's impaired ability to augment blood flow in response to a stimulus with aging in humans.

PULSE PRESSURE AMPLIFICATION AND AUGMENTATION INDEX IN ASSOCIATION WITH CARDIAC STRUCTURAL AND FUNCTIONAL DAMAGE

Objective: To investigate and compare the associations of pulse pressure amplification (PPA) and augmentation index (Aix) with asymptomatic cardiac structural and functional damage in an elderly Chinese population.Design and method: 1940 participants (mean age of 71.6 years) were included in the present study. Central blood pressure (BP) parameters were measured by SphygmoCor device. PPA and Aix were calculated as the ratio of central and brachial pulse pressures and the ratio of augmentation pressure and aortic pulse pressure, respectively. Cardiac structural and functional parameters including left ventricular mass index (LVMI), the ratio of peak early diastolic transmitral flow velocity and early diastolic lateral mitral annular velocity (E/Ea), were evaluated using standardized methods. Results: In correlation analysis, both PPA and Aix significantly correlated with LVMI and E/Ea ratio. When PPA and Aix separately put into same multivariate full-mode linear regression models, both PPA and Aix significantly associated with LVMI (regression coefficient [β] = 4.664, per 10% increase of PPA, P < 0.001; β = 1.998, per 10% increase of Aix, P = 0.02) and E/Ea ratio (β = 0.499, per 10% increase of PPA, P < 0.01; β = 0.152, per 10% increase of Aix, P = 0.18). When PPA and Aix both put into same multivariate stepwise linear regression models, only PPA were stayed in the model. When PPA and Aix separately put into same multivariate full-mode logistic regression models, only PPA was significantly associated with left ventricular hypertrophy (Odds ratio[OR]:1.242, 95% confidence interval[CI]:1.026–1.505, per 10% increase of PPA) and dysfunction (OR: 1.407, 95%CI: 1.087–1.820, per 10% increase of PPA). When PPA and Aix both put into same multivariate stepwise logistic regression models, only PPA were stayed in the model. In all multivariate models, brachial systolic BP was included and significantly associated with cardiac damage. Conclusions: PPA showed stronger BP-independent association with cardiac structural and functional damage than Aix.

PULSE PRESSURE AMPLIFICATION DIPPING PATTERN DURING SLEEP TIME

Objective: The difference in pulse pressure (PP) between peripheral arteries and the aorta, called pulse pressure amplification (PPamp), is a well-described physiological phenomenon which is independently associated with cardiovascular events. Recent studies suggest that it exhibits circadian variability. Our aim was to evaluate the 24 hour profile of peripheral and central hemodynamics and detect the factors associated with the circadian variability of PPamp. Design and method: In 497 consecutive subjects (aged 54 years, 56.7% male, 79.7% hypertensives) we assessed the circadian pattern of peripheral and central arterial hemodynamics by 24-hour evaluation of brachial and aortic blood pressure (BP), augmentation index (AI) and pulse wave velocity (PWV) using a validated brachial-cuff based oscillometric device (Mobil-O-Graph). Results: All parameters exhibited a circadian variation. Sleep dipping (decrease) pattern was observed for PPamp (Figure 1), brachial and aortic systolic BP, mean BP (Figure 2) and PWV (Figure 3), whereas a rising pattern (higher sleep than wake values) was observed for brachial PP, aortic PP (Figure 4) and AI (Figure 5). The factors independently associated with the less sleep-dipping in PPamp were: older age, lower height, the use of antihypertensive medication, sleep decrease in arterial stiffness (PWV); whereas female gender, the presence of hypertension, sleep increase of pressure wave reflections (AI), sleep decrease in heart rate and mean BP were associated with a greater sleep-dipping in PPamp (Table 1).Conclusions: These data provide further pathophysiological understanding of the mechanisms leading to PPamp dipping. Several implications regarding the clinical use of the aortic and brachial BP, especially during sleep time, are raised that should be addressed in future research.

CARDIOVASCULAR RISK FACTORS AND ARTERIAL STIFFNESS IN MEN AGED 41–43 YEARS

Objective: To study the relationship of individual cardiovascular risk factors with arterial stiffness and subclinical atherosclerosis. Design and method: The study is the part of a 32-year prospective cohort monitoring, beginning with childhood (11–12 years). The present cohort included 303 male subjects aged 41–43 years. Arterial stiffness (AS) was measured by aortic pulse wave velocity (PWV) and arterial wave reflections (augmentation index, Alx) with the use of SphygmoCor (AtCor Medical). Intima-media thickness (IMT) and subclinical atherosclerosis were estimateded by ultrasonography methods both in left and right carotid arteries. Results: Hypertension (H) was detected in 37,9%. PWV was significantly higher in the group with H. The risk of H development depended on hypertension presence in mother and did not depend on the presence of H in father. H was associated with the development of obesity, especially of the abdominal type and increased level of triglycerides. PWV was positively correlated with systolic (r = 0.248, p < 0.001) and diastolic blood pressure (BP) (r = 0.220, p < 0.001) measured on the brachial artery and with heart rate (r = 0.164, p < 0.01). A statistically significant positive correlation of the central aortic pressure (r = 0.326, p < 0.001) and central pulse pressure (r = 0.225, p < 0.001) with PWV was noted. When comparing arterial stiffness (AS) and duplex scan a correlation of mean IMT with the Alx (r = 0.134, p < 0.05) and augmentation pressure (r = 0.127, p < 0.05) was obtained, but no correlation between IMT and PWV was found. Correlation of AS with total cholesterol and glucose was also shown. Conclusions: The AS is closely related with H and develops already in the early stages, in a fairly young age. The AS in men group was not associated with the presence of dyslipidemia and diabetes melitus. The interrelation of arterial stiffness and the degree of early atherosclerotic vascular lesions is ambiguous.

Volume status and arterial blood pressures are associated with arterial stiffness in hemodialysis patients.

Arterial stiffness is a strong predictor of mortality in hemodialysis patients. In this study, we aimed to investigate possible relations of arterial stiffness with volume status determined by bioimpedance analysis and aortic blood pressure parameters. Also, effects of a single hemodialysis session on these parameters were studied. A total of 75 hemodialysis patients (M/F: 43/32; mean age: 53 ± 17) were enrolled. Carotid-femoral pulse wave velocity, augmentation index, and aortic pulse pressure were measured by applanation tonometry before and after hemodialysis. Extracellular fluid and total body fluid volumes were determined by bioimpedance analysis. Carotid-femoral pulse wave velocity (9.30 ± 3.30 vs 7.59 ± 2.66 m/s, p < 0.001), augmentation index (24.52 ± 9.42 vs 20.28 ± 10.19, p < 0.001), and aortic pulse pressure (38 ± 14 vs 29 ± 8 mmHg, p < 0.001) significantly decreased after hemodialysis. Pre-dialysis carotid-femoral pulse wave velocity was associated with age (r2 = 0.15, p = 0.01), total cholesterol (r2 = 0.06, p = 0.02), peripheral mean blood pressure (r2 = 0.10, p = 0.005), aortic-mean blood pressure (r2 = 0.06, p = 0.02), aortic pulse pressure (r2 = 0.14, p = 0.001), and extracellular fluid/total body fluid (r2 = 0.30, p < 0.0001). Pre-dialysis augmentation index was associated with total cholesterol (r2 = 0.06, p = 0,02), aortic-mean blood pressure (r2 = 0.16, p < 0.001), and aortic pulse pressure (r2 = 0.22, p < 0.001). Δcarotid-femoral pulse wave velocity was associated with Δaortic-mean blood pressure (r2 = 0.06, p = 0.02) and inversely correlated with baseline carotid-femoral pulse wave velocity (r2 = 0.29, p < 0.001). Pre-dialysis Δaugmentation index was significantly associated with Δaortic-mean blood pressure (r2 = 0.09, p = 0.009) and Δaortic pulse pressure (r2 = 0.06, p = 0.03) and inversely associated with baseline augmentation index (r2 = 0.14, p = 0.001). In multiple linear regression analysis (adjusted R2 = 0.46, p < 0.001) to determine the factors predicting Log carotid-femoral pulse wave velocity, extracellular fluid/total body fluid and peripheral mean blood pressure significantly predicted Log carotid-femoral pulse wave velocity (p = 0.001 and p = 0.006, respectively). Carotid-femoral pulse wave velocity, augmentation index, and aortic pulse pressure significantly decreased after hemodialysis. Arterial stiffness was associated with both peripheral and aortic blood pressure. Furthermore, reduction in arterial stiffness parameters was related to reduction in aortic blood pressure. Pre-dialysis carotid-femoral pulse wave velocity was associated with volume status determined by bioimpedance analysis. Volume control may improve not only the aortic blood pressure measurements but also arterial stiffness in hemodialysis patients.

Effect of Aerobic Exercise on Artery Stiffness and Cerebrovascular Pulsatility in Hypertensive and Non-Hypertensive Adults

Large elastic arteries (i.e. aorta, carotid) buffer pulsatile hemodynamics by dampening changes in pressure and flow. Stiffer central arteries, as seen in hypertension, transmit greater pulsatile hemodynamics into fragile cerebral vessels. Aerobic exercise is recommended for hypertensives (HTN), but its effects on artery stiffness and pulsatility in this group are unclear. PURPOSE: Investigate the effect of acute aerobic exercise on artery stiffness and cerebrovascular pulsatility in HTN and non-HTN adults. METHODS: 30 medicated HTN and 30 age, sex, and body mass index (BMI)-matched non-HTN adults (56±6 yrs, BMI 28.2±2.9 kg/m2; 32 men) underwent hemodynamic measures pre and 10 min post a 30-min cycling bout (55% peak oxygen consumption). Aortic stiffness was measured using carotid-femoral pulse wave velocity (cf PWV) and carotid artery (CA) stiffness was assessed with PWV-β via Ultrasound. Aortic mean (MP) and pulse pressure (PP; via radial generalized transfer function), and CA PP were measured by tonometry. CA and middle cerebral artery (MCA) blood velocity pulsatility index (PI) were measured using Doppler. RESULTS: cf PWV, MCA PI and CA PI increased and aortic PP decreased, post exercise compared to pre in both groups (p<0.05). Aortic MP and CA PP, PWV-β were unaltered post-exercise. Aortic MP was greater in HTN vs non-HTN. No other significant effects were detected. CONCLUSION: Acute aerobic exercise increases aortic stiffness and cerebrovascular hemodynamic pulsatility in both non-HTN and HTN individuals. These data suggest medicated-HTN have similar vascular responses to early recovery from acute aerobic exercise as non-HTN. Supported by a Foundation Research Grant from ACSM and AHA Pre doctoral FellowshipTable 1: Arterial stiffness and hemodynamic pulsatility pre/post acute exercise in non-HTN and HTN subjects.HTN, hypertensive; cf, carotid-femoral; PWV, pulse wave velocity; PI, pulsatility index; G, group; T, time; GxT, group-by-time interaction.

Resistance Exercise on Pulse Wave Reflection and Arterial Stiffness Between Trained and Untrained Individuals

Pulse wave reflection [augmentation index (AIx), augmentation pressure (AP)], and arterial stiffness [pulse wave velocity (PWV)] are indicative of cardiovascular health. Acute resistance exercise (RE) alters pulse wave reflection, and arterial stiffness, but responses in resistance-trained individuals is unclear. PURPOSE: To examine the responses in pulse wave reflection and arterial stiffness after RE in resistance-trained (RT) versus untrained (UT) individuals. METHODS: Twenty-one (RT: n=14; UT: n=7) individuals volunteered. Pulse wave reflection and arterial stiffness were collected at rest, and 10min following a control, or RE consisting of 3 sets of 10 repetitions at 75% 1-repetition maximum (1RM) on the leg press, lat pulldown, leg extension, chest press and leg curl. A 2x2x2 ANOVA was used to examine group (RT, UT) differences across conditions (RE, control) and time (Rest, Recovery). RESULTS: The groups were similar (p>0.05) for age, height, and BMI, but not weight (p<0.05). The 1RMs for all exercises, except leg extension (p=0.26), were different between groups. At rest, the groups were statistically different for the tension-time index [TTI (RT: 1999±282ms; UT: 2192±209ms, p=0.04)], diastolic pressure-time index [DPTI (RT: 2817±316ms; UT: 3047±171ms, p=0.003)], and PWV (RT: 5.5±0.7m/s; UT: 6.3±0.4m/s, p=0.0001). There were significant time by condition interactions for aortic pulse pressure (Rest: 34±6mmHg; Recovery: 37±8mmHg, p=0.01), AP (Rest: 5±3mmHg; Recovery: 6±5mmHg, p=0.003), AIx normalized at 75bpm (Rest: 8.7±12.6%; Recovery: 16.4±6.0%, p=0.004), and TTI (Rest: 2084.6±273.4ms; Recovery: 2760.9±463.3ms, p=0.0001) such that they increased during recovery, compared to rest after RE, and the control. There were condition by time interactions for DPTI (Rest: 2889.6±297.0ms; Recovery: 2394.9±458.3ms, p=0.005) and subendocardial viability ratio SEVR (Rest: 138.4±19.3%; Recovery: 86.6±33.0%, p=0.006) such that they increased after acute resistance exercise, compared to rest and the control. There were no significant changes in arterial stiffness. CONCLUSION: These data suggest that resistance-trained individuals have reduced workload of the heart and lower arterial stiffness at rest, but are similar to untrained individuals after acute resistance exercise.

Aortic Pulse Pressure Does Not Adequately Index Cardiovascular Risk Factor-Related Changes in Aortic Stiffness and Forward Wave Pressure.

Through the impact of conventional risk factors on arteries, several changes in aortic function contribute to cardiovascular events. It is nevertheless uncertain whether these effects are accurately reflected by changes in central aortic pulse pressure (PPc). We, therefore, aimed to determine the extent to which relations between modifiable risk factors and aortic function translate into increases in PPc. In 1,232 black South Africans from the South West Township (SOWETO) of Johannesburg, we determined risk factors and aortic function from carotid-femoral pulse wave velocity (PWV), aortic PPc, forward wave pressures (Pf), and reflected (backward) wave pressures (Pb) (applanation tonometry and SphygmoCor software). With adjustments for alternative risk factors and distending pressure (mean arterial pressure (MAP)), diabetes mellitus (treatment or HbA1c > 6.5%, n = 151) was associated with an increased PWV (7.10 ± 2.09 vs. 6.17 ± 2.00 m/s, P < 0.0001), and Pf (26 ± 8 vs. 24 ± 8 mm Hg, P < 0.005), but neither brachial PP (46 ± 14 vs. 45 ± 13, P = 0.19), PPc (36 ± 12 vs. 35 ± 11 mm Hg, P = 0.48), nor Pb (17 ± 6 vs. 17 ± 6 mm Hg, P = 0.83). Moreover, independent of alternative risk factors and MAP, uncontrolled hypertension (office blood pressure > 140/90 mm Hg, n = 433) was associated with an increased Pf (26 ± 12 vs. 24 ± 10 mm Hg, P < 0.01), but not with changes in brachial PP (45 ± 19 vs. 44 ± 17, P = 0.75), PPc (35 ± 16 vs. 35 ± 15 mm Hg, P = 0.93), or Pb (18 ± 8 vs. 17 ± 8 mm Hg, P = 0.46). Neither brachial nor aortic PP are adequate indexes of relations between the modifiable conventional risk factors, uncontrolled hypertension or diabetes mellitus, and risk-related aortic functional changes.

Single Session Mindfulness Meditation Reduces Aortic Pulsatile Load and Anxiety in Mild to Moderately Anxious Adults

Mindfulness meditation has been shown to have numerous health benefits when used over the course of days or weeks, but the effect of a single session on aortic pulsatility and anxiety is unclear. Therefore we sought to determine if a single session of mindfulness meditation could effectively reduce aortic pulsatile load and anxiety. Fourteen adults (24±8 years) with mild to moderate anxiety (≥8 Beck Anxiety Inventory (BAI)) participated in a 60 minute guided mindfulness meditation session. Baseline aortic pulsatile load (aortic pulse pressure × heart rate) and BAI were assessed approximately one week prior to the mindfulness meditation session during a study orientation. Aortic pulsatile load was assessed before, immediately after, and 60 minutes after the mindfulness meditation session. Anxiety was also assessed 60 minutes following meditation. The single mindfulness session reduced aortic pulsatile load from 2008±108 to 1730±85 a.u. immediately after meditation (p&lt;0.01). The reduction in aortic pulsatile load was maintained 60 minutes post‐meditation (1729±99 a.u.; p&lt;0.02). The BAI score was also significantly reduced 60 minutes post‐meditation compared to baseline (15±1 vs. 11±2; p&lt;0.02). Our findings demonstrate that even a single session of mindfulness meditation can have cardiovascular and psychological benefits for adults with mild to moderate anxiety. Reductions in pulsatile load may help to reduce damage to end organs such as the brain and kidneys, while reduced anxiety could help to prevent vascular dysfunction.Support or Funding InformationSupported by the Portage Health Foundation.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.