Changes In Pulse Pressure Research Articles

Changes in Precarious Employment and Health in the United States Amidst the COVID-19 Pandemic

This study aimed to investigate the association between changes in employment precarity and changes in health amidst the COVID-19 pandemic. We conducted an online survey of 623 U.S. adults at-risk for cardiovascular disease, which queried respondents on employment, food insecurity, and blood pressure measurements in the Fall of 2020 and retrospectively, in February 2020. Respondents were also queried on perceived stress in the Fall of 2020. We created a multidimensional precarious employment score (PES) using 13 survey indicators, that operationalized the following dimensions of employment precarity (PES range: 0–13): material rewards, working time arrangements, employment stability, workers’ rights, collective organization, interpersonal relations, and training opportunities. Using adjusted linear regression models, we investigated the association between a change in the PES and 1) change in systolic blood pressure, 2) change in pulse pressure, 3) change in food insecurity, and 4) perceived stress. Models controlled for race/ethnicity, age, gender, and education. Results indicated that employment precarity was 13 % higher between February and Fall 2020, particularly among women and non-Hispanic Black respondents. A change in the PES was associated with a change in food insecurity (β: 0.02; 95 % CI:0.01, 0.03) and higher perceived stress (β: 0.39; 95 % CI:0.25, 0.53). The PES was not associated with a change in systolic blood pressure (β: −0.22; 95 % CI:-0.76, 0.32) nor in pulse pressure (β: −0.33; 95 % CI: −0.73, 0.07). Policy approaches to mitigate the growth in employment precarity, and in turn food insecurity and stress, warrant consideration to prevent widening of health inequities.

Short-term effects of transcatheter aortic valve replacement on blood pressure and cardiac function in elderly patients with severe aortic stenosis.

Transcatheter aortic valve replacement (TAVR) is a standard treatment for elderly and high-risk patients with aortic valve stenosis (AS); however, its short-term effects on blood pressure (BP) and cardiac function are not clear. Therefore, we aimed to determine the short-term effects of TAVR in elderly patients (>75 years), who reflect the clinical situation in Japan. Twenty-eight consecutive elderly patients with severe AS and hypertension who underwent TAVR under general anesthesia were retrospectively investigated. All patients had hypertension that was well controlled with antihypertensive drugs. Serum brain natriuretic peptide level and peak velocity in the aortic valve were significantly reduced. TAVR induces an increase in BP that requires additional antihypertensive agents. There was no correlation between the change rate of SBP and stroke volume index (SVI), but there was a positive correlation between the rate of change in pulse pressure (PP) and SVI. This tendency was particularly observed in patients with low brachial-ankle pulse wave velocity (baPWV). We observed post-TAVR hypertension and required additional antihypertensive drugs. The increases in SVI and PP after TAVR resulted in post-TAVR hypertension. Moreover, post-TAVR hypertension is less likely to occur in elderly patients with a high baPWV, which indicates advanced arteriosclerosis.

Abstract 14746: Pulse Pressure More Strongly Associates With Subclinical Myocardial Injury Than Do Systolic and Diastolic Blood Pressures

Introduction: Long-standing hypertension is associated with subclinical myocardial injury expressed as chronically elevated cardiac troponin concentrations. Subclinical myocardial injury and subsequent diffuse myocardial fibrosis may represent important intermediaries between hypertension and risk of heart failure and cardiovascular (CV) death. The relative strength of the associations between systolic blood pressure (BP), diastolic BP and pulse pressure and subclinical myocardial injury is unknown. Aim: To assess the relative impact of systolic BP, diastolic BP and pulse pressure on subclinical myocardial injury. Methods: Cardiac troponin I (cTnI) was measured by a high-sensitivity assay (Abbott Diagnostics) in 32,968 participants of the fourth wave of the Trøndelag Health Study (HUNT4) from 2017 to 2019. The longitudinal substudy included participants from HUNT4 who also had BP measurements from the third wave of HUNT (HUNT3) from 2006 to 2008. This included 18,681 study participants. All study participants with a history of CV disease were excluded prior to analysis. We defined subclinical myocardial injury as cTnI ≥4ng/L for women and ≥6ng/L for men, and used logistic regression models adjusted for established CV risk factors. Results: The mean age was 52 (SD±17) years, and 56.9% were female. Cross-sectionally, pulse pressure was more strongly associated with subclinical myocardial injury (adjusted odds ratio [aOR] 1.08, 95% confidence interval [CI] 1.06-1.10) compared to systolic BP (aOR 1.05, 95% CI 1.04-1.06) and diastolic BP (aOR 1.02, 95% CI 0.99-1.04). Longitudinally, change in diastolic BP was the only BP variable associated with subclinical myocardial injury (aOR 1.03, 95% CI 1.01-1.06), compared to change in systolic BP (aOR 1.01, 95% CI 0.99-1.02) and change in pulse pressure (aOR 0.99, 95% 0.97-1.01, p for all comparisons < 0.05). Conclusions: At a given time, pulse pressure is the superior BP variable in predicting subclinical myocardial injury. Over time, only change in diastolic BP is associated with subclinical myocardial injury. High pulse pressure and longitudinal changes in diastolic BP could represent hypertension phenotypes at high risk for subclinical myocardial injury and subsequent increased CV risk.

Effects of Face Masks on Pulse Rate and Blood Pressure Components During Stairs Climbing.

The use of face masks has been associated with physiological changes in body. This study aims to know the changes in pulse rate and blood pressure components after wearing face masks during stairs climbing. An experimental study was conducted among 60 apparently healthy young adults between 18-35 years of age. The pulse rate and blood pressure of the participants were recorded during rest at ground floor and after climbing the stairs till 5th floor at brisk and regular pace without wearing the face masks. The uniform KN95 masks were distributed and proper coverage of nose, mouth and chin were ensured. After 5 minutes interval, the pulse rate and blood pressure were recorded again at rest in ground floor and after climbing stairs with use of KN95 masks. At rest, the difference in mean pulse rate was statistically significant after wearing masks in participants between 21-25 years of age (86.46±14.59 bpm, p=0.014). After climbing the stairs, the mean pulse rate (131.16±18.48 bpm), mean systolic blood pressure (137.67±16.13 mmHg) and mean rate pressure product (182.87±41.70) were higher in participants (age group: 26-30 years) wearing masks and the difference was statistically significant (p=0.001; 0.013; 0.001respectively). During stairs climbing, the change in mean systolic blood pressure (32.66±16.73 mmHg), mean pulse pressure (43.77±24.64 mmHg) and mean rate pressure product (96.58±37.23) were higher in participants (age group: 26-30 years) and the difference was statistically significant (p=0.036; 0.047 and 0.009 respectively). The changes in systolic blood pressure, pulse pressure and rate pressure product are found to increase after wearing face masks during stairs climbing. It can be suggestive of increase workload to the heart by wearing face masks in addition to climbing the stairs.

Relations of postural change in blood pressure with hypertension-mediated organ damage in middle-aged adults of the Framingham heart study: A cross-sectional study.

Dysregulation of compensatory mechanisms to regulate blood pressure (BP) upon postural change is a phenotype of BP variability and an emerging risk factor for cardiovascular outcomes. We assessed postural change in BP (starting 2 min after standing from a supine position), carotid-femoral pulse wave velocity (cfPWV), and markers of hypertension-mediated organ damage (HMOD) in the heart, kidney, and brain in Framingham Third Generation, Omni-2, and New Offspring Spouse Cohort participants. We related vascular measures (postural change in BP measures and cfPWV) with HMOD in 3,495 participants (mean age 47 years, 53% women) using multivariable logistic and linear regression models. In multivariable-adjusted models, we did not observe significant associations of vascular measures with presence of left ventricular hypertrophy, albuminuria, covert brain infarcts, or white matter hyperintensities (Bonferroni-adjusted P-values > 0.05/20 > 0.0025). In multivariable models, greater cfPWV (est. β = 0.11 ± 0.03; P < 0.001), but not postural change in BP measures (Bonferroni-adjusted P-values > 0.05/20 > 0.0025), was associated with higher white matter free water using brain magnetic resonance imaging. In multivariable models, greater postural change in pulse pressure was associated with higher urinary albumin-creatinine ratio (est. β = 0.07 ± 0.02; P < 0.001). No other postural change in BP measure was associated with urinary albumin-creatinine ratio (Bonferroni-adjusted P-values > 0.05/20 > 0.0025). In sex-specific analyses, higher cfPWV was associated with higher urinary albumin-creatinine ratio in men (est. β: 0.11 ± 0.04; P = 0.002) but not in women (est. β: 0.03 ± 0.03; P = 0.44). We also observed marginal to strong effect modification by above vs. at/below median postural change in BP for the association of cfPWV with urinary albumin-creatinine ratio (Bonferroni-adjusted interaction P < 0.001-0.01). Vascular measures were not related to left ventricular mass index or fractional anisotropy (Bonferroni-adjusted P-values > 0.05/20 > 0.0025). Baroreflex dysfunction is associated with greater subclinical kidney damage. Additionally, relations of higher aortic stiffness with greater kidney damage may be modified by associated baroreflex dysregulation.

The association of pulse pressure change with memory decline in middle-aged and older adults.

Less is known regarding the association of pulse pressure (PP) with memory function. This study aimed to characterize long-term patterns of PP in middle-aged and older adults and explore their impact on subsequent change in memory function. Data from the English Longitudinal Study of Ageing (ELSA, 2004-2018), were analyzed. Totally, 3587 dementia-free participants with three measurements of BP were included. All three visits of PP (2004-2012) were used to characterize longitudinal patterns of PP by group-based trajectory modeling (GBTM). Generalized estimating equation (GEE) models were fitted to explore the impact of PP trajectories on change in memory over a subsequent 6-year period (2012-2018). Using GBTM, three distinct trajectories of PP were identified: low-stable (38.1%), moderate-stable (48.6%), and elevated-increasing group (13.3%). GEE model suggested that memory declined over a 6-year period in all PP trajectories (all Ptime <0.001). The overall interactions between patterns of PP changes and time with memory were statistically significant (χ2 interaction =20.69, p=0.002). Compared to participants in the low-stable group, those in the moderate-stable and elevated-increasing group exhibited a faster decline in memory. Longitudinal patterns of moderate-stable and elevated-increasing PP were associated with an accelerated decrease in memory. Controlling BP instability may be a promising interventional strategy for preventing cognitive decline among older adults.

Dynamic changes of pulse pressure but not of pulse pressure variation during passive leg raising predict preload responsiveness in critically ill patients with spontaneous breathing activity

PurposeTo evaluate whether the changes in arterial pulse pressure (PP) and/or pulse pressure variation (PPV) during passive leg raising (PLR) can be used to evaluate preload responsiveness in patients with spontaneous breathing activity. Materials and methodsPatients ventilated with pressure support mode or totally spontaneously breathing were prospectively included. The values of PP and PPV were recorded before and at the end of PLR. The changes in cardiac index (CI) or the velocity-time integral (VTI) of the left ventricular outflow tract during PLR were tracked by the pulse contour analysis or transthoracic echocardiography. Patients exhibiting an increase in CI ≥ 10% or VTI ≥ 12% during PLR were defined as preload responders. ResultsAmong 33 patients included, 28 (80%) received norepinephrine and 14 were preload responders. The increase in PP > 2 mmHg in absolute value (4% in percentage) during PLR (PLRPP) predicted preload responsiveness with an area under the receiver operating characteristic (AUROC) of 0.76 ± 0.09 (p = 0.003 vs. AUROC of 0.5). The changes in PPV during PLR, however, failed to predict preload responsiveness (p = 0.82 vs. AUROC of 0.5). ConclusionIn patients with full spontaneous breathing activity, PLR-induced changes in PP had a fair ability to assess preload responsiveness even when norepinephrine was administered.Registration number:ClinicalTrials.gov (NCT04369027).

New-onset aortic dilatation in the population: a quarter-century follow-up.

Aortic size tends to increase with aging but the extent of this dynamic process has not been evaluated in long-term longitudinal population-based studies. We investigated the incidence of new-onset aortic root (AR) dilatation and its principal correlates among middle-aged adults over a 25-year time period. A total of 471 participants with measurable echocardiographic parameters at baseline and after a 25-year follow-up were included in the analysis. Sex-specific upper limits of normality for absolute AR diameter, AR diameter indexed to body surface area (BSA) and to height were derived from healthy normotensive PAMELA participants. New AR dilatation occurred in 7.4% (AR/BSA), 9.1% (AR/height) and 14.6% (absolute AR), respectively. According to the AR/height index, the risk of new dilation was similar in men and women. As for echocardiographic parameters, baseline AR diameter emerged as a key predictor of AR dilation, regardless of the diagnostic criteria and the 10-year change in LVMI was positively associated to new AR/height dilatation. No significant relationship was observed between baseline office and ambulatory systolic/diastolic blood pressure or their changes over time with incident AR dilatation. Baseline and the 25-year change in 24-h pulse pressure were negatively related to new AR dilatation. The incidence of AR dilatation from mid to late adulthood occurs in a small but clinically relevant fraction of participants and is unaffected by both office and out-office BP. It is significant related to baseline AR diameter and to the 25-year change in LVMI. Our data suggest that echocardiography performed in middle-aged individuals of both sexes may identify those at increased risk of future AR dilatation; moreover, preventing LVH may reduce the risk of progressive AR enlargement.

In essential hypertension, a change in the renal resistive index is associated with a change in the ratio of 24-hour diastolic to systolic blood pressure.

An increase in the renal resistive index (RRI) in patients with essential hypertension (EH) predicts deterioration in renal function. In patients with EH, changes in hemodynamic parameters significantly affect the RRI. This study aimed to define changes in Ambulatory Blood Pressure Monitoring (ABPM) parameters that are significantly associated with a change in RRI in patients with EH. We evaluated ABPM and the RRI in 96 patients with EH without organ extrarenal changes at baseline and after two years of follow-up. The relationships between changes in ABPM parameters and the RRI over the period were evaluated. After two years of follow-up, the increase in RRI was consequential. Simultaneously, 24-h systolic blood pressure increased significantly and 24-h diastolic blood pressure decreased. In the whole group and in the group with calculated cystatin C clearance (eGFRcyst) >/=90 ml/min/1.73 m2, the change in RRI significantly negatively correlated with the change in the ratio of 24-h diastolic to systolic blood pressure (D/S ratio), but also with the change in 24-h pulse blood pressure. However, in patients with eGFRcyst>90 ml/min/1.73 m2, only the change in the 24-h D/S ratio significantly correlated with the change in RRI. Based on the backward stepwise regression analysis, the change in RRI was significantly dependent only on the change in 24-h D/S ratio and not on the change in 24-h pulse pressure. A change in the ratio of diastolic to systolic pressure better reflects a change in RRI than a change in pulse pressure.

Abstract P081: Rethinking The Association Of Physical Performance With Blood Pressure Changes In Older Women: Findings Form The Women’S Health Initiative

Rethinking the Association of Physical Performance with Blood Pressure Changes in Older Women: Findings form the Women’s Health Initiative Background: This study evaluated the association between changes in physical performance and blood pressure (BP) (e.g., systolic [SBP], diastolic [DBP], pulse pressure) in older women. Methods: 5627 women (mean age 69.8 ± 3.7 y) with grip strength, chair stand, gait speed performance and clinic-measured BP at baseline and at least one follow-up (years 1, 3 or 6) were included. Generalized estimating equation analysis of multivariable models with standardized point estimates described the longitudinal association between physical performance and BP changes in the overall cohort, and in models stratified by baseline cardiovascular disease (CVD), time-varying antihypertensive medication use (none, ≥1) and enrollment age (65-69 y; 70-79 y). Results: Overall, each z-score unit increment in grip strength was associated with 0.54 mmHg (95% CI 0.06, 1.03) higher SBP, and 0.34 mmHg (95% CI 0.07, 0.62) higher DBP ( Table 1 ). In stratified models, a standardized increment in grip strength was associated with higher SBP in women without CVD (0.74; 95% CI 0.16-1.32), among antihypertensive medication users (0.89; 95% CI 0.41, 1.37) and non-users (0.35; 95% CI 0.01, 0.68), and in those aged 65-69 y (0.64; 95% CI 0.04, 1.23). Similarly, a standardized increment in any of the three performance measures was associated with modestly higher DBP in antihypertensive medication users, and those aged 70-79 y. Associations between any performance measure and pulse pressure change were not significant. Conclusion: These results suggest a positive, and statistically significant relationship between physical performance and BP that appears to be influenced by CVD history, antihypertensive medication use, and age. Total characters with table: 2,213 Table 1:

Body height determines carotid stiffness following resistance exercise in young Japanese men.

Height is inversely associated with an increase in arterial stiffness after habitual resistance exercise (RE). Considering that RE is performed during exercise prescriptions, the association between height and the acute effects of RE on arterial stiffness should be clarified. We investigated the effects of height on arterial stiffness following transient RE. Thirty-nine young Japanese men were studied under parallel experimental conditions [sham control (seated rest) and RE (5 sets of 10 repetitions at 75% of one-repetition maximum)], which were randomly ordered on two separate days. The subjects were divided into tertiles of height (each group, n = 13). The β-stiffness index (index of arterial stiffness), assessed by carotid pulse pressure and distension, was measured in all subjects. A significant interaction between time, height, and RE was found for the β-stiffness index (P = 0.01). RE significantly increased the β-stiffness index in the lower-height group (P < 0.001), but not in the middle- and higher-height groups. Height was negatively associated with an increase in β-stiffness index following RE, even after controlling the confounders, including exercise volume and changes in heart rate and carotid pulse pressure (P = 0.003). The mediation analysis demonstrated a mediating effect of carotid distension on the relationship between height and changes in the β-stiffness index. These results suggest that short height individuals have increased arterial stiffness following RE due to decreased mechanical distension, rather than through the widening of pulsatile pressure.

Inadequacy of Augmentation Index for Monitoring Arterial Stiffness: Comparison with Arterial Compliance and Other Hemodynamic Variables.

Augmentation Index (AIx) is used clinically for monitoring both wave reflections and arterial stiffness, which when increased is a risk factor of cardiovascular mortality and morbidity. We hypothesize that AIx is not solely related to vascular stiffness as described by arterial compliance and other hemodynamic parameters since AIx underestimates wave reflections. Aortic pressure and flow datasets (n = 42) from mongrel dogs were obtained from our experiments and Mendeley Data under various conditions. Arterial compliances based on the Windkessel model (Ct), the stroke volume (SV) to pulse pressure (PP) ratio (Cv = SV/PP), and at inflection pressure point (CPi) were computed. Other relevant hemodynamic factors are also computed. AIx was poorly associated with arterial stiffness calculated from Ct (r = 0.299, p = 0.058) or CPi (r = 0.203, p = 0.203), even when adjusted for heart rates. Ct and Cv were monotonically associated. Alterations in inflection pressure (Pi) did not follow the changes in pulse pressure (PP) (r = 0.475, p = 0.002), and Pi was quantitatively similar to systolic pressure (r = 0.940, p < 0.001). AIx is neither linearly correlated with arterial stiffness, nor with arterial compliance and several cardiac and arterial parameters have to be considered when AIx is calculated.

Roselle for hypertension in adults.

Hypertension is considered to be a serious health problem worldwide. Controlling and lowering blood pressure are of significant benefit to people with hypertension because hypertension is a risk factor for stroke, heart disease, and cardiovascular disease. Roselle, the tropical plant Hibiscus sabdariffa, also commonly called sour tea or red tea, has been used as both a thirst-quenching drink and for medicinal purposes. To assess the effect of Roselle on blood pressure in people with primary hypertension. For this update, the Cochrane Hypertension Information Specialist searched the following databases and trials registers for randomised controlled trials (RCTs): the Cochrane Hypertension Specialised Register (to 6 August 2021), Cochrane Central Register of Controlled Trials (CENTRAL;2021, Issue 7), MEDLINE Ovid (1946 to 5 August 2021), Embase Ovid (1974 to 5 August 2021), ProQuest Dissertations & Theses (to 6 August 2021), Web of Science Clarivate(to 7 August 2021), Food Science and Technology Abstracts Clarivate(to 7 August 2021), the WHO International Clinical Trials Registry Platform (to 6 August 2021), and the US National Institutes of Health Ongoing Trials Register ClinicalTrials.gov (to 6 August 2021). WesearchedGoogle Scholar andOpenSIGLE. Wealsohandsearchedlocal and regionalChinesedatabases: CBM, CMCC, TCMLARS, CNKI, CMAC, and the Index to Chinese Periodical Literature (to 14 September 2020), as well asThai databases(ThaiJO, CUIR, TDC, CMU e-Theses, TCTR)(to3 October 2020).There were no language or publication date restrictions. We sought RCTs evaluating the use of any forms of Roselle with placebo or no treatment in adults with hypertension. Our primary outcome was change in trough and/or peak systolic and diastolic blood pressure (SBP, DBP). Secondary outcomes were withdrawals due to adverse effects, change in pulse pressure, and change in heart rate. All search results were managed using Covidence and re-checked for the number of records, inclusion and exclusion of studies with Mendeleyreference management software. We used standard methodological procedures expected by Cochrane. Two review authors worked independently in parallel for screening (titles and abstracts, and full reports), data extraction, risk of bias assessment, and assessment of the certainty of the evidence using the GRADE approach. Any disagreements were resolved by discussion or by consultation with the third review author if necessary. We presented mean difference (MD) of change in SBP and DBP with their corresponding 95% confidence interval (CI). For this update, only one RCT with a parallel-group design involving 60 participants with type 2 diabetes mellitus fulfilled the inclusion criteria. This study investigated the effect of Roselle extract capsules (total dose of 5600 mg) compared with placebo (lactose) at eight weeks. The study was at low risk of selection bias, performance bias, and detection bias. Conversely, it was at high risk of attrition bias, reporting bias, and other bias (baseline imbalance). We have very little confidence in the effect estimate of Roselle on change-from-baseline in both SBP and DBP between the two groups. The MD of change in SBP was 1.65, 95% CI -7.89 to 11.19 mmHg, 52 participants, very low-certainty evidence. The MD of change in DBP was 4.60, 95% CI -1.38 to 10.58 mmHg, 52 participants, very low-certainty evidence. Our secondary outcomes of withdrawals due to adverse effects, change in pulse pressure, and change in heart rate were not reported. Due to the limited available data, no secondary analyses were performed (subgroup and sensitivity analysis). The evidence is currently insufficient to determine the effectiveness of Roselle compared to placebo for controlling or lowering blood pressure in people with hypertension. The certainty of evidence was very low due to methodological limitations, imprecision, and indirectness. There is a need for rigorous RCTs that address the review question.

Longitudinal physical performance and blood pressure changes in older women: Findings form the women's health initiative

BackgroundThis study evaluated the association between changes in physical performance and blood pressure (BP) (e.g., systolic [SBP], diastolic [DBP], pulse pressure) in older women. Methods5627 women (mean age 69.8 ± 3.7 y) with grip strength, chair stand, gait speed performance and clinic-measured BP at baseline and at least one follow-up (years 1, 3 or 6) were included. Generalized estimating equation analysis of multivariable models with standardized point estimates described the longitudinal association between physical performance and BP changes in the overall cohort, and in models stratified by baseline cardiovascular disease (CVD), time-varying antihypertensive medication use (none, ≥1) and enrollment age (65–69 y; 70–79 y). ResultsOverall, each z-score unit increment in grip strength was associated with 0.59 mmHg (95% CI 0.10, 1.08) higher SBP, and 0.39 mmHg (95% CI 0.11, 0.67) higher DBP. In stratified models, a standardized increment in grip strength was associated with higher SBP in women without CVD (0.81; 95% CI 0.23–1.39), among antihypertensive medication users (0.93; 95% CI 0.44, 1.41) and non-users (0.37; 95% CI 0.03, 0.71), and in those aged 65–69 y (0.64; 95% CI 0.04, 1.24). Similarly, a standardized increment in any of the three performance measures was associated with modestly higher DBP in antihypertensive medication users, and those aged 70–79 y. Associations between any performance measure and pulse pressure change were not significant. ConclusionThese results suggest a positive, and statistically significant relationship between physical performance and BP that appears to be influenced by CVD history, antihypertensive medication use, and age.

Measurement of Post-Exercise Response of Local Arterial Parameters Using an Adjustable Microfluidic Tactile Sensor.

In this work, we demonstrate an adjustable microfluidic tactile sensor for measurement of post-exercise response of local arterial parameters. The sensor entailed a polydimethylsiloxane (PDMS) microstructure embedded with a 5×1 resistive transducer array. The pulse signal in an artery deflected the microstructure and registered as a resistance change by the transducer aligned at the artery. PDMS layers of different thicknesses were added to adjust the microstructure thickness for achieving good sensor-artery conformity at the radial artery (RA) and the carotid artery (CA). Pulse signals of nine (n=9) young healthy male subjects were measured at-rest and at different times post-exercise, and a medical instrument was used to simultaneously measure their blood pressure and heart rate. Vibration-model-based analysis was conducted on a measured pulse signal to estimate local arterial parameters: elasticity, viscosity, and radius. The arterial elasticity and viscosity increased, and the arterial radius decreased at the two arteries 1min post-exercise, relative to at-rest. The changes in pulse pressure (PP) and mean blood pressure (MAP) between at-rest and 1min post-exercise were not correlated with that of heart rate and arterial parameters. After the large 1min post-exercise response, the arterial parameters and PP all went back to their at-rest values over time post-exercise.Clinical Relevance- The study results show the potential application of an affordable, user-friendly device for a more comprehensive arterial health assessment.

High Pulsatile Load Decreases Arterial Stiffness: An ex vivo Study.

Measuring arterial stiffness has recently gained a lot of interest because it is a strong predictor for cardiovascular events and all-cause mortality. However, assessing blood vessel stiffness is not easy and the in vivo measurements currently used provide only limited information. Ex vivo experiments allow for a more thorough investigation of (altered) arterial biomechanical properties. Such experiments can be performed either statically or dynamically, where the latter better corresponds to physiological conditions. In a dynamic setup, arterial segments oscillate between two predefined forces, mimicking the diastolic and systolic pressures from an in vivo setting. Consequently, these oscillations result in a pulsatile load (i.e., the pulse pressure). The importance of pulse pressure on the ex vivo measurement of arterial stiffness is not completely understood. Here, we demonstrate that pulsatile load modulates the overall stiffness of the aortic tissue in an ex vivo setup. More specifically, increasing pulsatile load softens the aortic tissue. Moreover, vascular smooth muscle cell (VSMC) function was affected by pulse pressure. VSMC contraction and basal tonus showed a dependence on the amplitude of the applied pulse pressure. In addition, two distinct regions of the aorta, namely the thoracic descending aorta (TDA) and the abdominal infrarenal aorta (AIA), responded differently to changes in pulse pressure. Our data indicate that pulse pressure alters ex vivo measurements of arterial stiffness and should be considered as an important variable in future experiments. More research should be conducted in order to determine which biomechanical properties are affected due to changes in pulse pressure. The elucidation of the underlying pulse pressure-sensitive properties would improve our understanding of blood vessel biomechanics and could potentially yield new therapeutic insights.

Effect of long-term testosterone replacement therapy on arterial stiffness and systemic endothelial function in male patients with hypogonadism

Abstract Purpose The study aims at providing the long-term effect of testosterone replacement therapy on systemic endothelial function, aortic stiffness and wave reflections in men with testosterone deficiency (TD). Methods This is a randomized single-center double-blind placebo-controlled trial involving 24 men (aged 51±9 years) with erectile dysfunction (ED) and total testosterone (TT) levels below 3.5 ng/ml randomised to receive either intramuscular (i.m) testosterone undecanoate (TU) injections (1000 mg as a single 4 mL i.m. injection at 0, 6, 18, 30 and 42 weeks) or an identical placebo at similar time points. A TU /placebo 2:1 randomization list was generated and patients were centrally assigned to one of the two arms, consecutively. Central blood pressure (BP), augmentation index (AIx), carotid-femoral pulse wave velocity (PWV) and brachial flow mediated dilatation (FMD) were measured at baseline, and at 18, 24, 30 and 44 weeks. Results The changes in central systolic BP and pulse pressure were more potent in the TU group compared to placebo group, however the decreases in these parameters were not statistically significant in point-of-time and time and group interaction. Repeated measures ANOVA revealed that the in point-of-time decrease in AIx was statistically significant in the group receiving TU (P=0.029) compared to men receiving placebo (figure). The maximal response in AIx was observed at 18 and 24 weeks (by 4.2% and 5.0%, respectively, all P&amp;lt;0.05). The interaction of time and group was also statistically significant (P=0.012) indicating significant differences between the treatment groups and time. PWV in the TU therapy group decreases during the whole study period, however the in point-of-time change was not statistically significant (P&amp;gt;0.05, figure). In men receiving TU the change in PWV was marginally significant only at 24 weeks (reduction by 0.34 m/s, P=0.05), whereas there were no significant differences in PWV between baseline and all other assessment time points. TU minimally increased brachial FMD up to 24 weeks (increase by 0.15%, P=0.05) from the beginning of therapy and the in point of the time change was not statistically significant (P&amp;gt;0.05, figure). Conclusion The 44-week TU i.m therapy was associated with a beneficial sustained effect on central AIx wave reflections thorough the whole study period. PWV decreased, particularly at 24 weeks, however the change in aortic elastic properties during the whole study session was not significant. Systemic endothelial function minimally improved compared to placebo. Given that AIx is an independent marker of cardiovascular disease and predictor of the corresponding risk, these findings have important implications to assess the effect of testosterone replacement interventions on cardiovascular performance and the corresponding risk of patients with ED and TD. Funding Acknowledgement Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Bayer Pharmaceuticals Figure 1. TU vs placebo Aix PWV and FMD changes

Impact of moderate altitude exposure on cardiovascular risk

Acute exposure to extreme altitude increases arterial stiffness by activation of the sympathetic and endothelin system as well as hypoxia-induced reactive oxygen species production. Beyond a certain individual threshold, these physiological adaptations represent a relevant cardiovascular risk factor. In this pilot study we investigated to what extent temporary exposure to moderate altitude, as present during hiking, skiing or in aeroplanes, leads to changes in vascular tone. Pulse wave parameters of 8 healthy individuals were assessed with a BR-102 plus pulse wave analyser (Schiller, Germany) at baseline (521 m) and after 24 h exposure to moderate altitude (2650 m). We identified a significant increase in heart rate (61 vs. 68/min, p = 0.021) as well as changes in central (35.6 vs. 41.4 mmHg, p = 0.024) and peripheral pulse pressure (44.7 vs. 52.6 mmHg, p = 0.006). Amplitudes of forward (21.6 vs. 25.4 mmHg, p = 0.012) and backward pulse waves (15.3 vs. 17.6 mmHg, p = 0.043) were significantly elevated. Pulse wave velocity showed no significant change from 5.8 m/s at baseline to 6.1 m/s at moderate altitude (p = 0.056). We show that temporary exposure to moderate altitude leads to mild changes in vascular tone reflected by pulse pressure and pulse wave amplitude in healthy adults. Although the observed effects were mild in our study, it indicates that adaptation capacity is of crucial importance and any restrictions by disease or simply with the process of ageing demand increased awareness, even in moderate altitude.

Abstract P118: Angiotensin Ii Hypertension-dependent Decrease In Circadian Rhythms Of Cardiovascular Parameters: Role Of Peroxisome Proliferator Activated Receptor-α

Decreases in circadian rhythms of cardiovascular parameters, such as day to night changes in mean arterial pressure (MAP), heart rate (HR), pulse pressure (PP), systolic (SP) and diastolic pressure (DP) are an index of cardiovascular disease. Peroxisome proliferator activated receptor - alpha (PPAR-α) has been shown to decrease inflammatory markers and hypertension a slow pressor dose of Angiotensin II (Ang II); however, the role of PPAR-α on cardiovascular parameters during the initial stages of Ang II infusion is unknown. We hypothesize that the absence of PPAR-α will cause a reduction in the day to night changes in MAP, HR, PP, SP and DP during the initial stages of a slow pressor dose of Ang II. Male (10 - 12 weeks old) PPAR-αknockout (KO) and wild-type (WT) mice were infused with Ang II (400 ng/kg/min) for three days. Radiotelemetry was used to measure the cardiovascular parameters. The baseline MAP values were: 100 + 10 mmHg (WT) and 108 + 9 mmHg for KO. The baseline HR values were: 530 + 10 bpm (WT) and 526 + 6 bpm (KO). The baseline PPs were 17 + 0.2 mmHg (WT) and 18 + 0.3 mmHg (KO). The baseline SBPs were 108 + 9 mmHg (WT) and 116 + 10 mmHg (KO). The baseline DBPs were 91 + 9 mmHg (WT) and 98 + 10 mmHg (KO). During the first three days of Ang II infusion, the change in day to night MAP was 20 ± 2 mmHg and 10 ± 2 mmHg in Ang II treated WT and KO mice, respectively. Changes in day to night HR were 25 ± 4 bpm and 46 ± 7 bpm for WT and KO mice, respectively. The day to night changes in PP were 8 ± 1 mmHg for WT and 2 ± 2 mmHg for KO mice. The day to night changes in SBPs were 20 ± 2 mmHg and 12 ± 3 mmHg for WT and KO mice, respectively. Changes in day to night DBPs were 18 ± 2 mmHg for WT and 9 ± 2 mmHg for KO mice. TBARS and Interleukin-17 were increased in heart homogenates of KO + Ang II (15 ± 2 μM) and (1.5 ± 0.3 ng/mL) vs WT + Ang II (11 ± 3 μM) and (1.0 ± 0.2 ng/mL). Nitrite/Nitrate was decreased in KO + Ang II (1.0 ± 0.1 nM) vs WT + Ang II (1.5 ± 0.5 nM). In summary, the absence of PPAR-α decreases the day to night changes in MAP, SBP, DBP and PP during the initial three days of a slow pressor dose of Ang II. In the absence of PPAR-α, increases in oxidative stress and inflammation are mechanisms that may contribute to the changes in the cardiovascular parameters and suggest the occurrence of cardiovascular diseases during a slow pressor dose of Ang II-infusion.

Case Studies in Physiology: Using premature ventricular contractions to understand the regulation of carotid artery longitudinal wall motion

Recent observations have identified a distinct longitudinal motion pattern of the common carotid artery, where the wall oscillates along its length both with (anterograde) and against (retrograde) the direction of blood flow. The regulation of the longitudinal pattern remains largely undetermined, in part due to difficulty uncoupling local pressure and flow stimuli from upstream energy sources. In this case study of a 29-yr-old male, we examine the regulation of longitudinal wall motion from the perspective of spontaneous premature ventricular contractions (PVCs). With respect to the pre-PVC beat, during the PVC, there was an 81% reduction in carotid blood velocity (96.8 to 18.4 cm/s), a 69% reduction in pulse pressure (58 to 18 mmHg), and a 59% reduction in apical left ventricular (LV) rotation (6.9 to 2.8°) as a result of reduced LV filling time. During this time, anterograde longitudinal wall motion was unchanged (0.06 mm), whereas retrograde motion was reduced by 91% (0.75 to 0.07 mm). During the compensated post-PVC beat, there were large increases in all outcomes, except for anterograde wall motion. Taken together, there appears to be little influence of either local or upstream factors on anterograde wall motion. Although retrograde wall motion generally mirrored blood pressure, blood velocity, and upstream cardiac movement, the primary motion regulator remains unclear. In this Case Study, we provide evidence against the role of blood velocity in regulating local wall motion and reinforce the potential importance of cardiac mechanics dictating the unique longitudinal motion pattern at the common carotid artery.NEW & NOTEWORTHY Benign arrhythmias can be a useful tool to probe new hypotheses in physiology. We tested the control of longitudinal motion of the common carotid artery wall using observations from spontaneous premature ventricular contractions in a healthy male. Forwards wall motion remained unchanged despite large deviations in local blood velocity and backwards wall motion mirrored changes in pulse pressure, blood velocity, and cardiac motion, thereby revising our original hypothesis of the control of longitudinal wall motion.