Arterial Blood Pressure Variability Research Articles

Anxiety symptom severity is associated with increased arterial blood pressure and arterial blood pressure variability in apparently healthy young adults

Introduction: Lifetime prevalence of anxiety disorders is approximately 30%, and anxiety is associated with an increased susceptibility to develop cardiovascular disease. Anxiety disorders have been linked to hypertension, and autonomic dysfunction has been posited as a contributing factor. However, anxiety symptom severity exists on a continuum, and it is less clear how anxiety severity is associated with blood pressure or beat-to-beat blood pressure variability, a hemodynamic biomarker that reflects dynamic cardiovascular regulatory mechanisms. The objective of this study was to test the hypothesis that self-reported anxiety symptom severity is positively associated with resting blood pressure and beat-to-beat blood pressure variability among healthy young adults without cardiometabolic disease. Methods: Resting beat-to-beat blood pressure (mmHg; finger plethysmography) and anxiety scores from a self-report anxiety symptom questionnaire (Zung Self-Rated Anxiety Scale, ZSRA) were collected in 53 healthy young adults (40 males, 13 females, age = 25 ± 4 yr, BMI = 25 ± 6 kg/m2). Following 10 minutes of quiet rest, signals were recorded over a 10-minute period with participants in a supine position, and the middle 8 minutes were used for analyses. Multiple linear regression was used to examine the independent relations of ZSRA with systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure (MAP), SAP standard deviation (SAPSD), DAP standard deviation (DAPSD), and MAP standard deviation (MAPSD) while controlling for age and sex. To further understand whether the observed relations between ZSRA and beat-to-beat blood pressure variability were explained by or independent of elevated absolute arterial pressure, partial correlations (rxy,z) were performed for ZSRA versus SAPSD, DAPSD, and MAPSD while partialling out the effect of SAP, DAP, and MAP, respectively. Results: ZSRA was significantly correlated with SAP (β = 0.34, p = 0.015), MAP (β = 0.32, p = 0.023), SAPSD (β = 0.36, p = 0.008), DAPSD (β = 0.35, p = 0.014), and MAPSD (β = 0.37, p = 0.008). When controlling for SAP, DAP, and MAP, ZSRA was independently associated with SAPSD (rxy,z = 0.34, p = 0.016), DAPSD (rxy,z = 0.35, p = 0.012), and MAPSD (rxy,z = 0.40, p = 0.005). Conclusion: Self-reported anxiety symptom severity is associated with increased blood pressure and beat-to-beat blood pressure variability, which indicates an important relationship between anxiety and blood pressure regulation across a continuum of symptom severity. This study is the first to show a relationship between anxiety and beat-to-beat blood pressure variability, independent of absolute mean blood pressure, among healthy young adults devoid of cardiometabolic disease. Our data build upon and align with previous findings that anxiety symptom severity is associated with increased muscle sympathetic nerve activity among healthy young adults and enhances our understanding of the relationship between anxiety and cardiovascular health, even among apparently healthy individuals. Funding provided by a grant from the Injury Prevention Research Center through the CDC (R49 CE003095; NDMJ). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Effects of Daylong Exposure to Indoor Overheating on Thermal and Cardiovascular Strain in Older Adults: A Randomized Crossover Trial.

Health agencies recommend that homes of heat-vulnerable occupants (e.g., older adults) be maintained below 24-28°C to prevent heat-related mortality and morbidity. However, there is limited experimental evidence to support these recommendations. To aid in the development of evidence-based guidance on safe indoor temperatures for temperate continental climates, we evaluated surrogate physiological outcomes linked with heat-related mortality and morbidity in older adults during simulated indoor overheating. Sixteen older adults [six women; median age: 72 y, interquartile range (IQR): 70-73 y; body mass index: ] from the Ottawa, Ontario, Canada, region (warm summer continental climate) completed four randomized, 8-h exposures to conditions experienced indoors during hot weather in continental climates (e.g., Ontario, Canada; 64 participant exposures). Ambient conditions simulated an air-conditioned environment (22°C; control), proposed indoor temperature upper limits (26°C), and temperatures experienced in homes without air-conditioning (31°C and 36°C). Core temperature (rectal) was monitored as the primary outcome; based on previous recommendations, between-condition differences were considered clinically meaningful. Compared with 22°C, core temperature was elevated to a meaningful extent in 31°C [; 95% confidence interval (CI): 0.5, 0.8] and 36°C (; 95% CI: 0.8, 1.1), but not 26°C (, 95% CI: 0.0, 0.3). Increasing ambient temperatures were also associated with elevated heart rate and reduced arterial blood pressure and heart rate variability at rest, as well as progressive impairments in cardiac and blood pressure responses to standing from supine. Core temperature and cardiovascular strain were not appreciably altered following 8-h exposure to 26°C but increased progressively in conditions above this threshold. These data support proposals for the establishment of a 26°C indoor temperature upper limit for protecting vulnerable occupants residing in temperate continental climates from indoor overheating. https://doi.org/10.1289/EHP13159.

Cerebral autoregulation derived blood pressure targets in elective neurosurgery

Poor postoperative outcomes may be associated with cerebral ischaemia or hyperaemia, caused by episodes of arterial blood pressure (ABP) being outside the range of cerebral autoregulation (CA). Monitoring CA using COx (correlation between slow changes in mean ABP and regional cerebral O2 saturation—rSO2) could allow to individualise the management of ABP to preserve CA. We aimed to explore a continuous automated assessment of ABPOPT (ABP where CA is best preserved) and ABP at the lower limit of autoregulation (LLA) in elective neurosurgery patients. Retrospective analysis of prospectively collected data of 85 patients [median age 60 (IQR 51–68)] undergoing elective neurosurgery. ABPBASELINE was the mean of 3 pre-operative non-invasive measurements. ABP and rSO2 waveforms were processed to estimate COx-derived ABPOPT and LLA trend-lines. We assessed: availability (number of patients where ABPOPT/LLA were available); time required to achieve first values; differences between ABPOPT/LLA and ABP. ABPOPT and LLA availability was 86 and 89%. Median (IQR) time to achieve the first value was 97 (80–155) and 93 (78–122) min for ABPOPT and LLA respectively. Median ABPOPT [75 (69–84)] was lower than ABPBASELINE [90 (84–95)] (p < 0.001, Mann-U test). Patients spent 72 (56–86) % of recorded time with ABP above or below ABPOPT ± 5 mmHg. ABPOPT and ABP time trends and variability were not related to each other within patients. 37.6% of patients had at least 1 hypotensive insult (ABP < LLA) during the monitoring time. It seems possible to assess individualised automated ABP targets during elective neurosurgery.

Fractal Analysis of the Cerebrovascular System Pathophysiology.

The cerebrovascular system is characterized by parameters such as arterial blood pressure (ABP), cerebral perfusion pressure (CPP), and cerebral blood flow velocity (CBFV). These are regulated by interconnected feedback loops resulting in a fluctuating and complex time course. They exhibit fractal characteristics such as (statistical) self-similarity and scale invariance which could be quantified by fractal measures. These include the coefficient of variation, the Hurst coefficient H, or the spectral exponent α in the time domain, as well as the spectral index ß in the frequency domain. Prior to quantification, the time series has to be classified as either stationary or nonstationary, which determines the appropriate fractal analysis and measure for a given signal class. CBFV was characterized as a nonstationary (fractal Brownian motion) signal with spectral index ß between 2.0 and 2.3. In the high-frequency range (>0.15Hz), CBFV variability is mainly determined by the periodic ABP variability induced by heartbeat and respiration. However, most of the spectral power of CBFV is contained in the low-frequency range (<0.15Hz), where cerebral autoregulation acts as a low-pass filter and where the fractal properties are found. Cerebral vasospasm, which is a complication of subarachnoid hemorrhage (SAH), is associated with an increase in ß denoting a less complex time course. A reduced fractal dimension of the retinal microvasculature has been observed in neurodegenerative disease and in stroke. According to the decomplexification theory of illness, such a diminished complexity could be explained by a restriction or even dropout of feedback loops caused by disease.

Static autoregulation in humans.

The process by which cerebral blood flow (CBF) remains approximately constant in response to short-term variations in arterial blood pressure (ABP) is known as cerebral autoregulation. This classic view, that it remains constant over a wide range of ABP, has however been challenged by a growing number of studies. To provide an updated understanding of the static cerebral pressure-flow relationship and to characterise the autoregulation curve more rigorously, we conducted a comprehensive literature research. Results were based on 143 studies in healthy individuals aged 18 to 65 years. The mean sensitivities of CBF to changes in ABP were found to be 1.47 ± 0.71%/% for decreased ABP and 0.37 ± 0.38%/% for increased ABP. The significant difference in CBF directional sensitivity suggests that cerebral autoregulation appears to be more effective in buffering increases in ABP than decreases in ABP. Regression analysis of absolute CBF and ABP identified an autoregulatory plateau of approximately 20 mmHg (ABP between 80 and 100 mmHg), which is much smaller than the widely accepted classical view. Age and sex were found to have no effect on autoregulation strength. This data-driven approach provides a quantitative method of analysing static autoregulation that can be easily updated as more experimental data become available.

Continual Learning for Cuffless Blood Pressure Measurement using PPG and ECG Signals.

Although numerous studies have been conducted on cuffless blood pressure (BP) estimation using machine learning methods, most of the data-driven models are static, with model parameters fixed after training is complete. However, BP is dynamic and the performance would degrade for a static model when the to-be predicted BP distribution deviates from the training BP distribution. In this paper, we propose a continual learning (CL) framework in which deep learning models are developed to learn dynamically and continuously for arterial BP (ABP) estimation with photoplethysmography (PPG) and electrocardiogram (ECG) waveforms. The effectiveness of the CL model is validated on UCI Repository and MIMIC-III database with a total of 132 individual samples, and compared with conventional training method. It was found that the CL model improved the ABP estimation accuracy in terms of mean absolute error (MAE) by 17.47% on average compared with conventional training model. Furthermore, the improvement increased with the variability of ABP. These results demonstrate that CL model has potential to estimate dynamic ABP, which has been challenging with conventional training.

Revealing the coupling directionality and synchronization between time series from physiological data by analysis of joint recurrences

We applied methods for determining the recurrence based phase synchronization index and the coupling directionality based on conditional probabilities of recurrence to analyze the direction of coupling and synchronization of time series obtained from experimental data. The activity of brain neurons, fluctuations in arterial blood pressure, and the respiratory rhythm of anesthetized rats were used as experimental data. For the first time, variants of changing the direction of the coupling between the analyzed time series before and during pain exposure were revealed. The relationship of pain exposure with the adjustment of the frequency of the variability of neuron activity of the brain to the frequency of the variability of arterial blood pressure or with the adjustment of the frequency of the variability of blood pressure to the respiratory rhythm with the subsequent occurrence of phase synchronization has been established.

Determinants of short-term blood pressure variability – the value of arterial stiffness

Abstract. Increased blood pressure variability is a significant parameter that affects the prognosis in patients with arterial hypertension, and is an independent predictor of cardiovascular events and mortality. The arterial elasticity is an important factor in maintaining a constant average blood pressure for adequate blood supply to inner organs against the background of dynamic blood pressure fluctuations. A decrease in the elastic properties of the arteries, and therefore, an increase in the arterial stiffness can be one of the potential mechanisms for the blood pressure variability violation. Objective. The aim of the study was to evaluate the possible relationships between arterial stiffness indicators and blood pressure variability indices in patients with hypertension based on the results of ambulatory blood pressure monitoring. Patients and methods. The results of ambulatory blood pressure monitoring of 172 patients with hypertension were analyzed. Arterial stiffness was assessed using the ambulatory arterial stiffness index - symmetric and asymmetric. SD, SDw, CV, SV, ARV, and BPVR indices were calculated to assess blood pressure variability. Analysis of the obtained results was carried out using Microsoft Excel 2010 and the STATISTICA version 10.0 software. Differences between groups were assessed by the Mann-Whitney method, correlations among blood pressure variability indices and ambulatory arterial stiffness indices were evaluated using Spearman`s rank correlation analysis. Significance was set at p ˂ 0.05. The results. Awake asymmetric ambulatory arterial stiffness index was significantly higher than asleep one, no statistically significant difference between asleep and 24-hour asymmetric ambulatory arterial stiffness index was established. The asleep symmetric ambulatory arterial stiffness index did not significantly differ from the awake one and was significantly higher than the 24-hour one. In comparison with asymmetric, for symmetric ambulatory arterial stiffness index statistically significant relationships were established for a greater number of blood pressure variability indices. In all statistically significant cases, the direction of the established relationship with arterial stiffness was only direct for the systolic blood pressure variability indices. Variability of diastolic blood pressure had a clear inverse relationship with arterial stiffness. Conclusions. The presence of pathogenetic interrelationships between arterial stiffness and blood pressure variability have been proven in the present study. The obtained results allow to state that arterial elasticity is an important component of blood pressure variability.

Hemodynamic effects of intraoperative 30% versus 80% oxygen concentrations: an exploratory analysis.

Supplemental oxygen leads to an increase in peripheral vascular resistance which finally increases systemic blood pressure in healthy subjects and patients with coronary artery disease, heart failure, undergoing heart surgery, and with sepsis. However, it is unknown whether this effect can also be observed in anesthetized patients having surgery. Thus, we evaluated in this exploratory analysis of a randomized controlled trial the effect of 80% versus 30% oxygen on intraoperative blood pressure and heart rate. We present data from a previous study including 258 patients, who were randomized to a perioperative inspiratory FiO2 of 0.8 (128 patients) versus 0.3 (130 patients) for major abdominal surgery. Continuous arterial blood pressure values were recorded every three seconds and were exported from the electronic anesthesia record system. We calculated time-weighted average (TWA) and Average Real Variability (ARV) of mean arterial blood pressure and of heart rate. There was no significant difference in TWA of mean arterial pressure between the 80% (80 mmHg [76, 85]) and 30% (81 mmHg [77, 86]) oxygen group (effect estimate -0.16 mmHg, CI -1.83 to 1.51; p = 0.85). There was also no significant difference in TWA of heart rate between the 80 and 30% oxygen group (median TWA of heart rate in the 80% oxygen group: 65 beats.min-1 [58, 72], and in the 30% oxygen group: 64 beats.min-1 [58; 70]; effect estimate: 0.12 beats.min-1, CI -2.55 to 2.8, p = 0.94). Also for ARV values, no significant differences between groups could be detected. In contrast to previous results, we did not observe a significant increase in blood pressure or a significant decrease in heart rate in patients, who received 80% oxygen as compared to patients, who received 30% oxygen during surgery and for the first two postoperative hours. Thus, hemodynamic effects of supplemental oxygen might play a negligible role in anesthetized patients. https://clinicaltrials.gov/ct2/show/NCT03366857?term=vienna&cond=oxygen&draw=2&rank=1.

The role of stress and sleep disorders in the development of cardiovascular complications in patients with arterial hypertension: what is important for an internist to know? A review

This publication discusses the mechanisms underlying the development of arterial hypertension on the background of stress, discusses the current problems of blood pressure control in patients with stress-induced sleep disorders, the clinical features of patients with hypersympathicotonia as the main mechanism for the development of arterial hypertension and blood pressure variability in patients with comorbid pathology, a diagnostic algorithm, as well as presenting current recommendations in the strategy for choosing the optimal antihypertensive therapy with the possibility of personalized choice in various clinical situations.

Ventriculo-Arterial Coupling for Predicting Cardiac Index Increase in Infants after Heart Surgery.

To test the ability of ventriculo-arterial coupling to predict cardiac index response after milrinone infusion. This was a retrospective, observational study. We measured arterial blood pressure and echocardiography-derived variables, including cardiac index, systemic vascular resistance index, arterial elastance, and end-systolic ventricular elastance before and after 18-24 hours of milrinone infusion. Ventriculo-arterial coupling was calculated as the ratio of arterial elastance to end-systolic elastance. Infants with over 15% increase in the cardiac index were defined as cardiac index responders. Logistical regression was used to evaluate predictors of cardiac index responders. We enrolled 92 infants who underwent cardiac surgery and received milrinone infusion, of which 45 infants were cardiac index responders. High ventriculo-arterial coupling (odds ratio= 5.534, 95% confidence interval 2.339 to 13.090) and high arterial elastance (odds ratio= 3.035, 95% confidence interval 1.459 to 6.310) were independently associated with cadiac index responders. Pre-milrinone ventriculo-arterial coupling predicted cardiac index responsiveness with a cutoff value of 1.12 (area under the curve = 0.900, 95% CI [0.819 to 0.953], p < 0.0001). Furthermore, we observed a decrease in the infant's ventriculo-arterial coupling, arterial elastance, and systemic vascular resistance index after milrinone infusion. In infants with congenital heart disease after surgery, a pre-milrinone ventriculo-arterial coupling greater than 1.12 can predict the increase in the cardiac index following milrinone infusion.

Co-authorship group significantly impacts reported arterial blood pressure variations in rodents exposed to intermittent hypoxia: a meta-research study

Co-authorship group significantly impacts reported arterial blood pressure variations in rodents exposed to intermittent hypoxia: a meta-research study

Cerebral blood flow response to cardiorespiratory oscillations in healthy humans

Dynamic cerebral autoregulation (CA) characterizes the cerebral blood flow (CBF) response to abrupt changes in arterial blood pressure (ABP). CA operates at frequencies below 0.15Hz. ABP regulation and probably CA are modified by autonomic nervous activity. We investigated the CBF response and CA dynamics to mild increase in sympathetic activity. Twelve healthy volunteers underwent oscillatory lower body negative pressure (oLBNP), which induced respiratory-related ABP oscillations at an average of 0.22Hz. We recorded blood velocity in the internal carotid artery (ICA) by Doppler ultrasound and ABP. We quantified variability and peak wavelet power of ABP and ICA blood velocity by wavelet analysis at low frequency (LF, 0.05-0.15Hz) and Mayer waves (0.08-0.12Hz), respectively. CA was quantified by calculation of the wavelet synchronization gamma index for the pair ABP-ICA blood velocity in the LF and Mayer wave band. oLBNP increased ABP peak wavelet power at the Mayer wave frequency. At the Mayer wave, ABP peak wavelet power increased by >70% from rest to oLBNP (p<0.05), while ICA blood flow velocity peak wavelet power was unchanged, and gamma index increased (from 0.49 to 0.69, p<0.05). At LF, variability in both ABP and ICA blood velocity and gamma index were unchanged from rest to oLBNP. Despite an increased gamma index at Mayer wave, ICA blood flow variability was unchanged during increased ABP variability. The increased synchronization during oLBNP did not cause less stable CBF or less active CA. Sympathetic activation seems to improve the mechanisms of CA.

Short exposure to high salt in drinking solution leads to a cardiovascular phenotype of hypertension without changes in the blood volume of rats.

What is the central question of this study? Is the cardiovascular phenotype of high blood pressure observed in rats salt loaded with 2% NaCl in drinking solution a blood volume-dependent hypertension? What is the main finding and its importance? Animals exposed to 2% NaCl drinking solution develop hypertension, with dominance of sympathetic outflow and high [Na+ ] in the cerebrospinal fluid, but without changes in the blood volume. The phenotype of salt-dependent hypertension might be related to accumulation of [Na+ ] in the cerebrospinal fluid, which makes it an interesting animal model in which to study the neuronal pathways involved in control of the circulation in osmotic challenge conditions. Evidence suggests that hypertension induced by high salt intake is correlated with an autonomic imbalance that favours sympathetic hyperactivity and an increase in vascular resistance, indicating a neurogenic component to this pathology. Although there are several animal models in which to study salt-induced hypertension with prolonged exposure to a high-sodium diet, here we sought to investigate whether the increase in arterial blood pressure of rats subjected to a short exposure to high salt, with 2% NaCl drinking solution instead of water, relies on changes in the circulating blood volume. Male Wistar rats were divided randomly into three groups: euhydrated (EU, n=10), salt loaded (SL, n=13) and water deprived (WD, n=6). The SL rats exhibited a significant increase in mean arterial blood pressure, with a large low-frequency component of systolic arterial blood pressure variability, when compared with the EU group. Circulating blood volume did not differ between SL and EU rats, but it was lower in WD rats. Compared with EU rats, the [Na+ ] in cerebrospinal fluid was higher in SL rats and similar in magnitude to the WD rats. Plasma [Na+ ] did not differ between SL and EU rats, but it was higher in WD rats. Collectively, our data suggest that the hypertension induced by a short exposure to high salt intake closely resembles a neurogenic mechanism, but not a blood volume-dependent mechanism, with cumulative [Na+ ] in the cerebrospinal fluid that could be associated with changes in the neurochemistry of autonomic nuclei, which are highly susceptible to osmotic stress related to high salt consumption.

Increased cerebral vascular resistance underlies preserved cerebral blood flow in response to orthostasis in humans on a high-salt diet.

Cerebral blood flow autoregulation protects brain tissue from blood pressure variations and maintains cerebral perfusion pressure by changes in vascular resistance. High salt (HS) diet impairs endothelium-dependent vasodilation in many vascular beds, including cerebral microcirculation, and may affect vascular resistance. The aim of present study was to determine if 7-day HS diet affected the reactivity of middle cerebral artery (MCA) to orthostatic challenge in healthy human individuals, and if autoregulatory mechanisms and sympathetic neural regulation were involved in this phenomenon.Twenty-seven persons participated in study (F:21, M:6, age range 19-24). Participants consumed 7-day low-salt (LS) diet (< 2.3g kitchen salt/day) and afterwards 7-day HS diet (> 11.2g kitchen salt/day). Blood and urine analysis and anthropometric measurements were performed after each diet. Arterial blood pressure, heart rate and heart rate variability, and cerebral and systemic hemodynamic parameters were recorded simultaneously with transcranial Doppler ultrasound and The Task Force®Monitor in response to orthostatic test.Participants remained normotensive during HS diet. Following both, the LS and HS dietary protocols, mean cerebral blood flow (CBF), as well as the velocity time integral and diastolic blood pressure decreased, and cerebral pulsatility index increased after rising up. Importantly, cerebrovascular resistance significantly increased in response to orthostasis only after HS diet. Urine concentration of noradrenaline and vanillylmandelic acid, baroreflex sensitivity (BRS), and sympathetic neural control was significantly decreased in HS diet.Results suggest that CBF in response to orthostatic test was preserved in HS condition due to altered vascular reactivity of MCA, with increased cerebrovascular resistance and blunted BRS and sympathetic activity.

Odnos varijabilnosti arterijskog pritiska iz ambulatornog 24-časovnog monitoringa arterijskog pritiska sa ehokardiografskim parametrima u bolesnika pod antihipertenzivnom terapijom

Introduction: Variability of systolic daytime arterial pressure was until recently a controversial parameter but is now recognized as an independent prognostic risk factor for stroke in hypertensive patients. Blood pressure variability is a quantitative index of spontaneous daily and nocturnal variations in systolic and diastolic arterial blood pressure and has been proposed as a risk factor for inducing subclinical damage to target organs in arterial hypertension. Besides varying degrees of left ventricular myocardial hypertrophy (LVH), patients with hypertension also exhibit accompanying diastolic dysfunction of the left ventricle as an early sign of hypertensive damage, even when myocardial hypertrophy does not develop. The variability of pressure over 24 hours in Ambulatory Blood Pressure Monitoring (ABPM) has not been sufficiently studied in terms of correlation with echocardiographic parameters in controlled hypertension. Methods: A total of 196 adequately treated patients with stage 2 hypertension, with a target of achieving normotension less than 140/90, were examined. The total of 196 patients, 109 males and 87 females, with a mean age of 49.3 ± 8.4 years, untreated or inadequately treated patients with stage 2 hypertension (mean BP before treatment 167/106 mmHg) were divided into three groups according to blood pressure variability parameters. Alongside standard methods: medical history, clinical examination, and electrocardiogram (ECG), 24-hour ambulatory arterial pressure monitoring (ABPM, so-called blood pressure holter) was performed with 24-hour, daytime, and nighttime variability of systolic and diastolic blood pressure as well as Color and Tissue Doppler echocardiography after adequate treatment. Results: Elevated blood pressure variability was observed in 66/196 patients (34%) in group V despite good pressure regulation, while 130/169 (66%) had normal variability - group C (control). A subgroup ExtV was particularly highlighted within group V with extreme variability of daytime systolic BP (SD&gt;20 mmHg) - 15/66 patients (8%). Evaluation of left ventricular myocardial mass index (LVMI) showed no difference in the degree of LVH between groups C and V. In the subgroup ExtV (from group V with extreme blood pressure variability), comprising 15/66 patients (8%), a significant difference in the degree of left ventricular myocardial hypertrophy was found between groups C and V regarding extreme variability (p&lt;0.01). There was no difference concerning gender and age structure. Statistical analysis of investigated 24-hour blood pressure parameters and echocardiographic parameters did not show significant correlation through calculation of the linear correlation coefficient between mean arterial pressure measured by 24-hour ambulatory pressure monitoring and standard deviations of daytime and nighttime pressure and the degree of left ventricular myocardial hypertrophy (linear correlation coefficients r &lt;0.20), as expected. However, there is a moderate but significant correlation between the best echocardiographic parameter of diastolic function, E/E' ratio, and variability of daytime systolic pressure: r= 0.41. Only the subgroup with extreme variability ExtV in terms of daytime systolic pressure has a statistically significant correlation with the degree of LVMI myocardial hypertrophy, r=0.51. Conclusion: One-third of the examined patients, 66/196 patients (34%) in group V, had elevated blood pressure variability despite good pressure regulation. There was no significant difference in the degree of left ventricular myocardial hypertrophy between the investigated parameters of 24-hour blood pressure and echocardiographic indices, except in extreme variability ExtV (P&lt;0.01). However, there is a moderate but significant correlation between the best echocardiographic parameter of diastolic function, E/E' ratio, and variability of daytime systolic pressure: r= 0.41. Only the subgroup with extreme variability ExtV in terms of daytime systolic pressure has a statistically significant correlation with the degree of LVMI myocardial hypertrophy, r=0.51.

Abstract P137: Proteomic And Phosphoproteomic Profiling Reveals Structural And Functional Changes In The Abdominal Aorta Of Male Sprague Dawley Rats That Associate With Age-dependent Hypertension

Aim: We hypothesized that alterations in the expression and phosphorylation of abdominal aorta protein networks contribute to arterial remodeling in age-dependent hypertension (HTN). Methods: Mean arterial pressure (MAP) and blood pressure variability (BPV) were measured by femoral artery cannulation in 3- and 16-month-old (mo) male Sprague-Dawley (SD) rats (N=4/group). Quantitative proteomic/phosphoproteomic analysis was performed on individual abdominal aorta. The differentially expressed/phosphorylated proteins identified at 3 vs. 16-mo (

PD56-04 ASSESSMENT OF CHANGES IN ARTERIAL BLOOD PRESSURE AFTER NEPHRECTOMY FOR KIDNEY CANCER VAPANCR (UROCCR 26)_PROSPECTIVE STUDY

You have accessJournal of UrologyCME1 May 2022PD56-04 ASSESSMENT OF CHANGES IN ARTERIAL BLOOD PRESSURE AFTER NEPHRECTOMY FOR KIDNEY CANCER VAPANCR (UROCCR 26)_PROSPECTIVE STUDY Pierre Bigot, Jean-Christophe Bernhard, Nicolas Doumerc, François-Xavier Nouhaud, Idir Ouzaid, Patrick Saulnier, Arnaud Mejean, Morgan Rouprêt, and Karim Bensalah Pierre BigotPierre Bigot More articles by this author , Jean-Christophe BernhardJean-Christophe Bernhard More articles by this author , Nicolas DoumercNicolas Doumerc More articles by this author , François-Xavier NouhaudFrançois-Xavier Nouhaud More articles by this author , Idir OuzaidIdir Ouzaid More articles by this author , Patrick SaulnierPatrick Saulnier More articles by this author , Arnaud MejeanArnaud Mejean More articles by this author , Morgan RouprêtMorgan Rouprêt More articles by this author , and Karim BensalahKarim Bensalah More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002636.04AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Kidney is an essential regulator of arterial blood pressure (ABP) via the renin-angiotensin system. The impact of kidney surgery on ABP is debated. Our objective was to evaluate the consequences of kidney surgery for cancer on ABP. METHODS: We carried out a multicenter prospective study (NCT03218319) and included 200 patients who underwent nephrectomy for cancer between January 2018 and September 2020 at 7 academic centers from the UROCCR network. The study obtained approval from Ethical Committee (2017-A00127-46). Inclusions criteria were a localized cancer eligible to nephrectomy and the absence of pre-existing hypertension. ABP was monitored according to the recommendations for home blood pressure measurement. Four measurements were taken after 5 minutes of sitting rest, before breakfast and four additional measurements were taken in the evening before bedtime. Measurements were done during three consecutive days (average of 18 values). ABP evaluation was done the week before nephrectomy, one month and six months after nephrectomy. A renin assessment was done one week before surgery and 6 months after surgery. The primary endpoint was the occurrence of a clinically significant change in ABP at 6 months. A change in ABP was considered clinically significant if the variation in systolic and / or diastolic ABP was ≥ 5 mmHg or if medical anti-hypertensive treatment was required. RESULTS: ABP and renin measurements were evaluable for 182 (91%) and 136 (68%) patients, respectively. There were 112 males and 88 females with a median age of 54 years. Radical (RN) and Partial nephrectomy (PN) were performed in 42 (21%) and 158 (79%) patients, respectively. At 6 months, 55 (30.2%) patients had a significant increase in their ABP and 12 (6.5%) patients started an antihypertensive treatment. Type of surgery was not associated with increases in ABP (31.6 % PN vs 25% RN; p=0.559) nor prescription of antihypertensive drug (4.79% PN vs 12.5 % RN; p=0.089). At 6 months, renin was not significantly higher than before surgery (16.098 vs 15.231, p=0.686). In multivariable analysis, type of surgery, age, sex, BMI, smoking, diabetes and dyslipidemia were not associated with significant changes in ABP. CONCLUSIONS: Renal surgery for cancer induces significant variations in ABP in 30% of patients. Type of surgery is not associated with ABP outcomes. ABP after surgery seems not be related to renin secretion. Longer follow-up and additional patients will be necessary to determine whether this rise in ABP can have a consequence on the occurrence of cardio-vascular events. Source of Funding: This study was granted by the French Association of Urology (AFU) © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e954 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Pierre Bigot More articles by this author Jean-Christophe Bernhard More articles by this author Nicolas Doumerc More articles by this author François-Xavier Nouhaud More articles by this author Idir Ouzaid More articles by this author Patrick Saulnier More articles by this author Arnaud Mejean More articles by this author Morgan Rouprêt More articles by this author Karim Bensalah More articles by this author Expand All Advertisement PDF DownloadLoading ...

Predicting Time to Death After Withdrawal of Life-Sustaining Measures Using Vital Sign Variability: Derivation and Validation.

OBJECTIVES:To develop a predictive model using vital sign (heart rate and arterial blood pressure) variability to predict time to death after withdrawal of life-supporting measures.DESIGN:Retrospective analysis of observational data prospectively collected as part of the Death Prediction and Physiology after Removal of Therapy study between May 1, 2014, and May 1, 2018.SETTING:Adult ICU.PATIENTS:Adult patients in the ICU with a planned withdrawal of life-supporting measures and an expectation of imminent death.INTERVENTIONS:None.MEASUREMENTS AND MAIN RESULTS:Vital sign waveforms and clinical data were prospectively collected from 429 patients enrolled from 20 ICUs across Canada, the Czech Republic, and the Netherlands. Vital sign variability metrics were calculated during the hour prior to withdrawal. Patients were randomly assigned to the derivation cohort (288 patients) or the validation cohort (141 patients), of which 103 and 54, respectively, were eligible for organ donation after circulatory death. Random survival forest models were developed to predict the probability of death within 30, 60, and 120 minutes following withdrawal using variability metrics, features from existing clinical models, and/or the physician’s prediction of rapid death. A model employing variability metrics alone performed similarly to a model employing clinical features, whereas the combination of variability, clinical features, and physician’s prediction achieved the highest area under the receiver operating characteristics curve of all models at 0.78 (0.7–0.86), 0.79 (0.71–0.87), and 0.8 (0.72–0.88) for 30-, 60- and 120-minute predictions, respectively.CONCLUSIONS:Machine learning models of vital sign variability data before withdrawal of life-sustaining measures, combined with clinical features and the physician’s prediction, are useful to predict time to death. The impact of providing this information for decision support for organ donation merits further investigation.

Incidence of perioperative respiratory complications in patients undergoing elective open upper abdominal surgery under general anaesthesia: Smokers versus non-smokers - An observational study

Background: Smoking has various deleterious effects and peri-operative complications. Pulmonary complications following abdominal surgery are frequent and associated with increased morbidity and mortality and length of hospital stay. Aims and Objectives: Hence, this study was done to observe the incidence of various respiratory and cardiovascular complications in the perioperative period in patients undergoing elective open upper abdominal surgery under general anaesthesia among smokers versus non-smokers. The various complications which are studied are as follows - Arterial desaturation, Severe coughing, Laryngospasm, Bronchospasm, Recurrent apnea, Variations in Mean Arterial Blood Pressure and Heart rates. Materials and Methods: Male patients ASA-I, II or III, aged 20–60 years undergoing elective open upper abdominal surgery under general anaesthesia were selected. They were divided into two groups (during pre-anaesthetic checkup) - smokers (&gt;10 cigarette/day for the past 1 year and continued smoking till admission), non-smokers (who never smoked). General anaesthesia was given according to standard protocol. Results: The smokers had higher incidence of laryngospasm as well as bronchospasm but they were not statistically significant. Smokers had low baseline SpO2; greater fall in SpO2 just after extubation, before sending to PACU and on day 1 which were statistically significant. Smokers had raised MAP just after extubation, on day 1 and day 2 which were statistically significant. Conclusion: Smokers had increased incidences of respiratory and hemodynamic complications than non-smokers.