Analysis Of Blood Pressure Variability Research Articles

Correlation Analysis of Blood Pressure Variability, Crystalloid Osmotic Pressure, and Cardiovascular Events in Maintenance Hemodialysis Patients.

This study aimed to analyze the correlation between blood pressure variability (BPV), crystalloid osmotic pressure, and cardiovascular events (CEs) in patients undergoing maintenance hemodialysis (MHD). This retrospective analysis was conducted on 71 patients with end-stage kidney disease who underwent hemodialysis at Beilun District People's Hospital from September 2021 to September 2022. The patients were divided into two groups based on the occurrence of CEs: a cardiovascular event group and a non-cardiovascular event group. The 71 patients were divided into two groups based on the occurrence of CEs: the CEs group (25 patients who experienced CEs) and the non-CEs group (46 patients who did not experience CEs). The CEs group had significantly higher levels of crystalloid osmotic pressure, standard deviation of systolic BP (SBP-SD), coefficient of variation of SBP (SBP-CV), SD of diastolic BP (DBP-SD), and DBP-CV (P < .05). Multivariate logistic regression analysis identified crystalloid osmotic pressure, SBP-CV, and DBP-CV as independent risk factors for CEs. The ROC curve analysis indicated that the combined predictive value of crystalloid osmotic pressure, SBP-CV, and DBP-CV was significant, with an area under the curve (AUC) of 0.963. Elevated crystalloid osmotic pressure, SBP-CV, and DBP-CV are critical risk factors with strong predictive value for predicting CEs in MHD patients.

P099 EXERCISE TRAINING FURTHER ATTENUATES BLOOD PRESSURE VARIABILITY AND RENAL DAMAGE IN HYDROCHLOROTHIAZIDE TREATED-HYPERTENSIVE AND POSTMENOPAUSAL RATS

Background and Objective: Considering that blood pressure variability (BPV) has been associated with damage to target organs such as the kidney, this study aimed to investigate the effects of hydrochlorothiazide (HCTZ) combined with exercise training (CET) on BPV, as well as renal tissue morphology, function, inflammation, and oxidative stress. Methods: Female spontaneously hypertensive rats (SHR) were divided into 4 ovariectomized groups (n=5-6/group): sedentary (OS), sedentary + HCTZ (OSH), trained (OT), and trained + HCTZ (OTH). Both HCTZ (3 mg/kg) and CET (3 days/week) were administered for 8 weeks. Blood pressure was directly recorded for BPV analysis. Results: Renal function, morphology, inflammation and oxidative stress were assessed. The OSH, OT, and OTH groups had lower systolic BP (OSH: 189±13; OT: 179±5; OTH: 174±15 mmHg) compared to the OS group (208±15 mmHg). Only the combination of the drug with CET promoted a reduction in BPV variance. The HCTZ-treated groups showed lower plasma creatinine levels and increased creatinine clearance compared to the OS group. Treated groups showed a reduction in fields of 51–100% of interstitial tubule fibrosis when compared to the OS group; and the OTH group also showed reduction in fields in the range of 26–50% vs. other groups. The HCTZ-treated groups showed a reduction in protein oxidation. Renal catalase and IL10/TNF-alpha ratio were increased in the OTH group. Positive correlations were obtained between SBP variance and SBP (r=0.72), plasma creatinine (r=0.58), and levels of TNF-α (r=0.69), hydrogen peroxide (r=0.61), and protein oxidation (r=0.66) in renal tissue. Conclusions: Our results highlight the enhanced efficacy of the combination of HCTZ and CET compared to the use of either drug alone in the model studied. This combination effectively reduced BPV, resulting in beneficial changes in renal inflammatory and redox profiles, inducing morphological and functional benefits in hypertensive ovariectomized rats. Financial support: FAPESP (2022/04050-1), CNPq, CAPES-PROSUP, UNINOVE.

Effect of remimazolam and propofol anesthesia on autonomic nerve activities during Le Fort I osteotomy under general anesthesia: blinded randomized clinical trial.

This study evaluated the effect of remimazolam and propofol on changes in autonomic nerve activity caused by surgical stimulation during orthognathic surgery, using power spectrum analysis of blood pressure variability (BPV) and heart rate variability (HRV), and their respective associations with cardiovascular fluctuations. A total of 34 patients undergoing Le Fort I osteotomy were randomized to the remimazolam (Group R, 17 cases) or propofol (Group P, 17 cases) groups. Observables included the low-frequency component of BPV (BPV LF; index of vasomotor sympathetic nerve activity), high-frequency component of HRV (HRV HF; index of parasympathetic nerve activity), balance index of the low- and high-frequency components of HRV (HRV LF/HF; index of sympathetic nerve activity), heart rate (HR), and systolic blood pressure (SBP). Four observations were made: (1) baseline, (2) immediately before down-fracture, (3) down-fracture, and (4) 5 min after down-fracture. Data from each observation period were compared using a two-way analysis of variance with a mixed model. A Bonferroni multiple comparison test was performed in the absence of any interaction. One-way analysis of variance followed by Tukey's multiple comparisons test was performed when a significant interaction was observed between time and group, with P < 0.05 indicating statistical significance. Evaluation of autonomic nerve activity in comparison with baseline during down-fracture showed a significant increase in BPV LF (P < 0.001), an increasing trend in HRV LF/HF in Group P, and an increasing trend in HRV HF in Group R. There were no significant differences in HR or SBP between the two groups. During down-fracture of Le Fort I osteotomy, sympathetic nerve activity was predominant with propofol anesthesia, and parasympathetic nerve activity was predominant with remimazolam anesthesia.

Does cardiovascular autonomic modulation correspond to the increase in dim-light onset of melatonin? A preliminary analysis

Introduction: The endogenous circadian system promotes the rise in melatonin approximately every 24 hours. In the laboratory, dim light melatonin onset (DLMO) is used as the gold standard method to assess circadian phase. Exogenous melatonin affects cardiac sympathovagal balance and vasomotor sympathetic modulation. Whether or not the endogenous increase in melatonin corresponds to changes in cardiovascular autonomic modulation is unclear. Objective: To evaluate if the timing of DLMO corresponds to the timing of changes in cardiovascular autonomic indices. Methods: Five healthy adults (3 females, age 23.8±SD1.8 y) completed a minimum of four nights of sleep regularization by maintaining a self-selected 8h in bed each night before the experiment. The day after regularization, they reported to the laboratory ~8 hours before bedtime. Measurements for melatonin and cardiovascular autonomic modulation started 6 hours before bedtime and continued 1 hour after. Saliva samples were collected every 30 minutes. At the end of every hour, 10 minutes of continuous R-R intervals (R-R) and systolic blood pressure (SBP) were recorded via electrocardiogram and beat-to-beat finger photoplethysmography, respectively. As currently established, DLMO was defined as the interpolated time for melatonin increase over 3pg/ml. Cardiovascular autonomic indexes were run through CardioSeries v.2 to create a temporal series for R-R interval and systolic blood pressure. Cardiac autonomic modulation was assessed by applying the spectral analysis using the fast Fourier transformation method and time domain analysis of heart rate variability (HRV) and spectral analysis of blood pressure variability (BPV). For each autonomic index, data were plotted and fitted with a segmental linear regression to reveal the intercept of the two segments to define the autonomic onset (AO). A paired t-test compared the difference between DLMO and AO times. Bland-Altman plots with a 95% limit of agreement (LOA) identified the distribution of differences between the methods. Additionally, a one-sample t-test compared the differences between methods to a fixed time clock range. Data are shown as mean ± SD and significance was set as p&lt;0.05. Results: AO time calculated for all indexes from HRV and BPV were not statistically different compared to DLMO time (R-R: +16±86 mins, P=0.70; root mean square of successive differences (RMSSD): -20±91 mins, P=0.67; low frequency (LF) nu: +29±52 mins, P=0.74; high frequency (HF) nu: -43±91 mins, P=0.23; LFHF: -26±73 mins, P=0.47; SBP: -14±104 mins, P=0.78; LFSBP: -6±107 mins, P=0.90). The Bland Altman plots did not identify any systematic difference between AO and DLMO times. The smallest difference was LFnu with a LOA 95% from -73 to +131 minutes, while the largest difference was LFSBP with LOA 95% from -217 to +204 minutes. Additionally, the difference between DLMO and AO LFnu times (LFnu: +29±52) was statistically similar from -36 to +95 minutes. Conclusion: In young healthy adults, our preliminary data shows that AO times of cardiovascular autonomic indexes correspond to salivary DLMO. A larger dataset with more frequent simultaneous measurements of melatonin and cardiovascular autonomic modulation are essential to confirm our preliminary findings. Medical Research Foundation of Oregon, OHSU OFDIR, R01HL163232. 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.

Allopurinol and blood pressure variability following ischemic stroke and transient ischemic attack: a secondary analysis of XILO-FIST.

Blood Pressure Variability (BPV) is associated with cardiovascular risk and serum uric acid level. We investigated whether BPV was lowered by allopurinol and whether it was related to neuroimaging markers of cerebral small vessel disease (CSVD) and cognition. We used data from a randomised, double-blind, placebo-controlled trial of two years allopurinol treatment after recent ischemic stroke or transient ischemic attack. Visit-to-visit BPV was assessed using brachial blood pressure (BP) recordings. Short-term BPV was assessed using ambulatory BP monitoring (ABPM) performed at 4 weeks and 2 years. Brain MRI was performed at baseline and 2 years. BPV measures were compared between the allopurinol and placebo groups, and with CSVD and cognition. 409 participants (205 allopurinol; 204 placebo) were included in the visit-to-visit BPV analyses. There were no significant differences found between placebo and allopurinol groups for any measure of visit-to-visit BPV. 196 participants were included in analyses of short-term BPV at week 4. Two measures were reduced by allopurinol: the standard deviation (SD) of systolic BP (by 1.30 mmHg (95% confidence interval (CI) 0.18-2.42, p = 0.023)); and the average real variability (ARV) of systolic BP (by 1.31 mmHg (95% CI 0.31-2.32, p = 0.011)). There were no differences in other measures at week 4 or in any measure at 2 years, and BPV was not associated with CSVD or cognition. Allopurinol treatment did not affect visit-to-visit BPV in people with recent ischemic stroke or TIA. Two BPV measures were reduced at week 4 by allopurinol but not at 2 years.

Impact of exercise training associated with enalapril treatment on blood pressure variability and renal dysfunctions in an experimental model of arterial hypertension and postmenopause.

In this study, we aimed to investigate the effects of the concurrent exercise training (CET) associated with the enalapril maleate on blood pressure variability (BPV) and renal profile in an experimental model of arterial hypertension (AH) and postmenopause. Female ovariectomized spontaneously hypertensive rats (SHR) were distributed into 4 groups (n = 8/group): sedentary (SO), sedentary + enalapril (SOE), trained (TO) and trained + enalapril (TOE). Both enalapril (3mg/kg) and CET (3 days/week) were conducted during 8 weeks. Blood pressure (BP) was directly recorded for BPV analyses. Renal function, morphology, inflammation and oxidative stress were assessed. The SOE, TO e TOE groups presented decreased systolic BP compared with SO. Both trained groups (TO and TOE) presented lower BPV and increased baroreflex sensitivity (TO: 0.76 ± 0.20 and TOE: 1.02 ± 0.40 vs. SO: 0.40 ± 0.07 ms/mmHg) compared with SO group, with additional improvements in TOE group. Creatinine and IL-6 levels were reduced in SOE, TO and TOE compared with SO group, while IL-10 was increased only in TOE group (vs. SO). Enalapril combined with CET promote reduction in lipoperoxidation (TOE: 1.37 ± 0.26 vs. SO: 2.08 ± 0.48 and SOE: 1.84 ± 0.35 μmol/mg protein) and hydrogen peroxide (TOE: 1.89 ± 0.40 vs. SO: 3.70 ± 0.19 and SOE: 2.73 ± 0.70 μM), as well as increase in catalase activity (vs. sedentary groups). The tubulointerstitial injury was lower in interventions groups (SOE, TO and TOE vs. SO), with potentialized benefits in the trained groups. Enalapril combined with CET attenuated BPV and baroreflex dysfunctions, probably impacting on end-organ damage, as demonstrated by attenuation in the AH-induced renal inflammations, oxidative stress and morphofunctional impairments in postmenopausal rats.

Abstract 061: Continuous And Cyclic Components Of Blood Pressure Profile Have Impact On Different Brain Areas In Controlled Hypertensive Patients

Increase in arterial blood pressure consistently damages the connectivity and function of the brain. While this evidence is becoming more widely accepted, the effects of daily fluctuations and variability in blood pressure levels on the brain are still not well understood. Our study investigated the impact of blood pressure variability (BPV) on cognitive function and white matter brain structure in a cohort of hypertensive patients under optimal BP control. We used diffusion tensor imaging (DTI-MRI) to assess white matter injury, neuropsychological tests such as the Montreal Cognitive Assessment (MoCA) to evaluate cognitive function, and 24-hour ambulatory blood pressure monitoring to measure BPV. Spectral analysis of BPV allowed us to measure both the cyclic and the continuous components of arterial blood pressure profile. We found that the Fractional Anisotropy of the Middle Cerebellar Peduncle was correlated with the cyclic component of both diastolic and systolic blood pressure. Additionally, a significant association between the continuous component of both diastolic and systolic blood pressure and the Anterior Thalamic Radiation was detected.. Finally, cognitive functions measured by MoCA were correlated with the continuous component of both diastolic and systolic blood pressure (Table). Our results suggest that the continuous component of blood pressure negatively impacts white matter regions associated with cognitive impairment, while the cyclic component is associated with alterations in brainstem regions where nervous vagal control is coordinated.

Spinal Cord Stimulation Prevents Autonomic Dysreflexia in Individuals with Spinal Cord Injury: A Case Series.

Spinal cord injury (SCI) results in severe cardiovascular dysfunction due to the disruption of supraspinal control. Autonomic dysreflexia (AD), an uncontrolled rise in blood pressure in response to peripheral stimuli including common bowel routine, digital anorectal stimulation (DARS), reduces the quality of life, and increases morbidity and mortality. Recently, spinal cord stimulation (SCS) has emerged as a potential intervention to mitigate unstable blood pressure following SCI. The objective of this case series was to test the real-time effect of epidural SCS (eSCS) at the lumbosacral spinal cord, the most common implant location, on mitigating AD in individuals with SCI. We recruited three individuals with cervical and upper thoracic motor-complete SCI who have an implanted epidural stimulator. We demonstrated that eSCS can reduce the elevation in blood pressure and prevent DARS-induced AD. The blood pressure variability analysis indicated that eSCS potentially reduced vascular sympathetic nervous system activity during DARS, compared to without eSCS. This case series provides evidence to support the use of eSCS to prevent AD episodes during routine bowel procedures, improving the quality of life for individuals with SCI and potentially reducing cardiovascular risks.

Impairment on Cardiovascular Autonomic Modulation in Women with Migraine.

Autonomic dysfunction, such as reduced vagally mediated heart rate variability, has been suggested in headache patients but is still uncertain when considering primary headache disorders. This study aims to compare the heart rate and blood pressure variability and baroreflex sensitivity between women with migraine and controls. A migraine (n = 20) and a control group (n = 20) of age-matched women without headache were evaluated. Heart rate variability was analyzed through frequency-domain using spectral analysis presenting variance, low-frequency (LF; 0.04-0.15 Hz) and high-frequency (HF; 0.15-0.4 Hz) bands and by time domain (root mean square of successive R-R interval differences, RMSSD). Blood pressure variability was analyzed with spectral analysis and baroreflex sensitivity with the sequence method. Migraine group had lower heart rate variability characterized by a reduction in total variance, LF oscillations (sympathetic/vagal modulation) and HF oscillations (vagal modulation), and a reduction in SD and RMSSD compared to control group. No difference was found in the blood pressure variability analysis. Regarding baroreflex sensitivity, migraine group had decreased values of total gain, gain down and up compared to control group. Women with migraine exhibited autonomic modulation alterations, expressed by decreased values of heart rate variability and baroreflex sensitivity, but not by differences in blood pressure variability.

Feasibility of Ultra-Short-Term Analysis of Heart Rate and Systolic Arterial Pressure Variability at Rest and during Stress via Time-Domain and Entropy-Based Measures.

Heart Rate Variability (HRV) and Blood Pressure Variability (BPV) are widely employed tools for characterizing the complex behavior of cardiovascular dynamics. Usually, HRV and BPV analyses are carried out through short-term (ST) measurements, which exploit ~five-minute-long recordings. Recent research efforts are focused on reducing the time series length, assessing whether and to what extent Ultra-Short-Term (UST) analysis is capable of extracting information about cardiovascular variability from very short recordings. In this work, we compare ST and UST measures computed on electrocardiographic R-R intervals and systolic arterial pressure time series obtained at rest and during both postural and mental stress. Standard time-domain indices are computed, together with entropy-based measures able to assess the regularity and complexity of cardiovascular dynamics, on time series lasting down to 60 samples, employing either a faster linear parametric estimator or a more reliable but time-consuming model-free method based on nearest neighbor estimates. Our results are evidence that shorter time series down to 120 samples still exhibit an acceptable agreement with the ST reference and can also be exploited to discriminate between stress and rest. Moreover, despite neglecting nonlinearities inherent to short-term cardiovascular dynamics, the faster linear estimator is still capable of detecting differences among the conditions, thus resulting in its suitability to be implemented on wearable devices.

Different cardiovascular responses to exercise training in hypertensive women receiving β-blockers or angiotensin receptor blockers: A pilot study

ABSTRACT Aim To verify the influence of β-blockers or angiotensin receptor blockers on cardiovascular responses to exercise training in hypertensive post-menopausal women. Methods Postmenopausal women were allocated into: healthy control group (CON; n = 9); angiotensin receptor blockers users (ARB; n = 19); and β-adrenergic blockers users (BB; n = 19). Before and after 12 weeks of combined (aerobic and resistance) exercise training they were evaluated by: heart rate (HR) and its variability (HRV), blood pressure (BP) under stress (Cold pressor and Stroop color tests), and ambulatorial BP and its variability. Results In ambulatorial BP analysis only in ARB group awake systolic BP decreased (p = .011; ARB: From 122 ± 11 to 117 ± 9; BB: From 118 ± 7 to 114 ± 5; CON: From 121 ± 7 to 127 ± 11 mmHg). There were time effects in BP reactivity to stress, where BP reactivity after Stroop color and Cold pressor test decreased in all groups. In BP variability analysis, only BB group has significative decreased values in systolic SD24 (p = .007; ΔARB = −0.3 ± 2.0; ΔBB = −1.3 ± 2.0; ΔCON = 0.8 ± 1.7 mmHg) and SDdn (p = .006; ΔARB = −0.2 ± 1.6; ΔBB = −1.3 ± 2.0; ΔCON = 0.4 ± 2.1 mmHg). HRV analysis demonstrated that post-training, only in BB group LF/HF decreased (p = .001; ΔARB = 0.1 ± 0.8; ΔBB = −0.4 ± 1.5; ΔCON = 1.0 ± 1.7). Conclusion ARB present pronounced responses in awake ambulatorial systolic BP, while β-blockers users present greater responses in BP variability. Besides that, exercise can mitigate BP reactivity to stress with no differences between groups. Lastly, there were no major differences in HRV. Trial registry at “Clinicaltrials.gov” NCT03529838

Abstract 9374: The Attenuation of Blood Pressure Lability Assessed by Frequency Analysis of Very Short-Term Continuous Blood Pressure Recording Reflects the Hemodynamic Aggravation in Heart Failure Patients with Reduced Ejection Fraction

Introduction: The lower blood pressure variability (BPV) assessed by 24-hour ambulatory bloop pressure (BP) monitoring predicts cardiac events in heart failure with reduced ejection fraction (HFrEF) patients. However, the trends of BPV assessed by short-term continuous BP recording in HFrEF patients remains unknown. Hypothesis: We recently reported a novel method of BPV analysis which is focused on the power spectral density (PSD) of 30-min continuous BP recording. In the PSD, we defined the integrated area of PSD from 0.01Hz to 0.1Hz as an index of short-term BPV (BP lability index: BLI) (Figure 1). Since the worsening of cardiac function decreases the dynamic variability of BP, we hypothesized that reduced cardiac function lowers BLI. In this study, we investigated how the worsening of cardiac function alters BLI. Methods: We compared 33 HFrEF patients with 15 hypertensive (HT) patients as a normal cardiac function. We assessed baseline characteristics, the value of brain natriuretic peptide (BNP), echocardiography and 30-min continuous BP in those patients. BP time series in each subject was converted to PSD by the Fourier transform. Results: Compared to HT, HFrEF patients showed lower left ventricular ejection fraction (LVEF) (33.8±11.8 vs. 68.9±6.8 %, p&lt;0.001) and higher E/e’ (17.5±10.8 vs. 10.5±2.7, p=0.002), indicating the hemodynamic aggravation. In continuous BP, HFrEF reduced both averaged systolic BP (122.0±18.1 vs. 137.9±19.7 mmHg, p=0.006) and pulse pressure (50.1±13.9 vs. 59.2±14.9 mmHg, p=0.037). BLI was significantly lower in HFrEF patients than that in HT (2.07±0.98 vs. 2.64±0.95, p=0.010]. Interestingly, the patients with reduced LVEF and high E/e’ showed lower BLI (Figure 2). Furthermore, BLI negatively associated with BNP (r=-0.38, p=0.012) (Figure 3). Conclusions: BLI was lower in HFrEF patients than that in HT patients with normal cardiac function. BLI has a potential to develop a novel marker of hemodynamic assessment in HFrEF patients.

Noninvasive Biomarkers for Cardiovascular Dysfunction Programmed in Male Offspring of Adverse Pregnancy.

[Figure: see text].

Efeito agudo do Mat Pilates sobre a variabilidade da pressão arterial ambulatorial em mulheres após a menopausa

Introdução: Após a menopausa mulheres tem maior risco de desenvolver doenças cardiovasculares. A prática de exercício físico é um dos tratamentos para e redução da incidência dessas doenças, e o método Pilates consiste em um programa completo de condicionamento físico. Objetivos: Verificar as respostas da Monitorização Ambulatorial da Pressão Arterial (MAPA) e da Variabilidade da Pressão Arterial após uma única sessão de Mat Pilates em mulheres após a menopausa não obesas. Métodos: Este é um estudo cruzado randomizado com 15 mulheres pós-menopáusicas normotensas, que participaram de uma única sessão de Mat Pilates e de uma sessão de controle. A sessão de Pilates durou 50 minutos, com 5 minutos de aquecimento. Em cada exercício, houve 1 série de 10 repetições com 45 segundos de descanso entre as séries. A sessão controle teve a mesma duração, mas as voluntárias permaneciam sentadas. A MAPA foi avaliada durante 24 horas após a intervenção. Estatística: Utilizou-se ANOVA de dois fatores com post hoc de Newman-Keuls para análise das variáveis da MAPA e teste t de Student para análise da variabilidade de pressão arterial. Resultados: Não houve diferença significativa (p &lt;0,05) nas respostas da pressão arterial sistólica e diastólica durante 24h, vigília e sono ou em sua variabilidade entre as sessões de Pilates e Controle. Conclusão: O Mat Pilates não reduziu os valores pressóricos da MAPA ou sua variabilidade em mulheres após a menopausa não obesas.

Blood Pressure Variability and Baroreflex Sensitivity in Premature Newborns-An Effect of Postconceptional and Gestational Age.

Introduction: Cardiovascular system is the vitally important system in the dynamical adaptation process of the newborns to the extrauterine environment. To reliably detect immaturity in the given organ system, it is crucial to study the development of the organ functions in relation to maturation process.Objectives: The objective was to determine the changes in the spontaneous short-term blood pressure variability (BPV) and baroreflex sensitivity (BRS) reflecting various aspects of cardiovascular control during the process of maturation in preterm babies and to separate effects of gestational age and postnatal age.Methods: Thirty-three prematurely born infants without any signs of cardio-respiratory disorders (gestational age: 31.8, range: 27–36 weeks; birth weight: 1,704, range: 820–2,730 grams) were enrolled. Continuous peripheral blood pressure signal was obtained by non-invasive volume-clamp photoplethysmography method during supine rest. The recordings of 250 continuous beat-to-beat blood pressure values were processed by spectral analysis of BPV (assessed measures: total power, low frequency and high frequency powers of systolic BPV) and BRS calculation. For each infant we also assessed systolic, diastolic and mean blood pressures, heart rate and respiratory rate.Results: With the postconceptional age, BPV measures decreased (for total power: Spearman correlation coefficient rs = −0.345, P = 0.049; for low frequency power: rs = −0.365, P = 0.037; for high frequency power rs = −0.349; P = 0.046); and BRS increased significantly (rs = 0.448, P = 0.009). The further analysis demonstrated that these effects were more attributable to gestational age than to postnatal age. BRS correlated negatively with BPV magnitude (rs = −0.479 to −0.592, P = 0.001–0.005). Mean blood pressure and diastolic blood pressure increased during maturation (rs = 0.517 and 0.537, P = 0.002 and 0.001, respectively) while heart rate and respiratory rate decreased (rs = −0.366 and −0.516, P = 0.036 and 0.002, respectively).Conclusion: We conclude that maturation process is accompanied by an increased involvement of baroreflex buffering of spontaneous short-term blood pressure oscillations. Gestational age plays a dominant role not only in BPV changes but also in BRS, mean blood pressure, diastolic blood pressure and heart rate changes.

Autonomic biomarkers of shock in idiopathic systemic capillary leak syndrome.

ObjectiveThe term Idiopathic Systemic Capillary Leak Syndrome (ISCLS) refers to an uncommon condition of severe distributive shock, resulting from an abrupt shift of fluids and proteins from the intravascular to the interstitial compartment. We hypothesise that the autonomic nervous system (ANS) fails in regulating the response to hypovolemia in acute ISCLS and that ANS variables characterise the progression to the recovery.DesignProspective cohort study of patients admitted to ICU for severe ISCLS flares.SettingSingle, referral center in Italy for ISCLS.PatientsAnalysis of cardiovascular signals recorded during seven severe ISCLS attacks and one prodromal period in five patients.InterventionsANS was studied non-invasively by means of heart rate variability (HRV) and blood pressure variability analysis, as an estimation of vagal and sympathetic modulation directed to the heart and vessels. Heart rate and systolic arterial pressure (SAP) variability were also used to assess baroreflex sensitivity. ANS variables were measured during the subsequent phases which characterise ISCLS flares, namely the acute phase, the post-acute phase, and the recovery phase.Measurements and main resultsHRV was severely depressed during the acute phase accounting for the loss of ANS modulation during massive capillary extravasation. This phase was characterised by shock and impaired baroreflex control, which allowed SAP to oscillate driven by respiratory activity. Impending shock and transition from shock to a post-acute phase were marked by change of baroreflex spectral variables. The baroreflex control was fully restored during recovery.ConclusionsANS modulation and baroreflex control are severely impaired during the acute haemodynamic instability which characterises ISCLS crises and their progressive restoration may be a clue of improvement. ANS indices during ISCLS flares might serve as useful biomarkers, able to timely announce the transition from one phase to the subsequent one, thus helping to adapt therapy accordingly.

Predictive value of within-visit and visit-to-visit blood pressure variability for all-cause mortality: the Minhang Study

Blood pressure variability is a common physiological phenomenon; however, the association between within-visit and visit-to-visit variability in blood pressure and all-cause mortality remains uncertain. We conducted a retrospective analysis of blood pressure variability among 11 721 adults who underwent blood pressure measurement on three occasions within a period of 6 months. Within-visit and visit-to-visit variability was quantified using the standard deviation and maximum--minimum difference between measures. The predictive effect of this variability on all-cause mortality was evaluated using Kaplan--Meier survival curves and Cox regression analysis. The incidence of all-cause mortality was significantly higher for participants in the top quintile of within-visit and visit-to-visit blood pressure variability and for those with sustained high within-visit variability. Within-visit variability was not retained as a risk factor after adjustment in Cox regression models. The hazard ratio for mortality increased from 48 to 55% for the top quintile of visit-to-visit blood pressure variability and from 56 to 61% for sustained high within-visit variability. The risk of mortality remained statistically higher even if visit-to-visit blood pressure variability was added to the model, including consistency of within-visit blood pressure variability and vice versa. Visit-to-visit and sustained high within-visit blood pressure variability were significant positive prognostic factors for all-cause mortality. Our findings underlined the clinical significance of achieving stable blood pressure in an effective plan of hypertension management.

Coconut Oil Supplementation Does Not Affect Blood Pressure Variability and Oxidative Stress: A Placebo-Controlled Clinical Study in Stage-1 Hypertensive Patients.

Exploring an alternative to improve the clinical management of hypertension, we tested the hypothesis that food supplementation with coconut oil (EVCO), alone or combined with aerobic exercise training, could exert an antihypertensive effect (primary outcome) in patients with stage 1 hypertension. Forty-five hypertensive volunteers of both genders participated in a placebo-controlled clinical trial. The volunteers were submitted to 24-hour ambulatory blood pressure monitoring, analysis of blood pressure variability (BPV), measurement of serum malondialdehyde (MDA) and nutritional assessment. Results indicate that EVCO consumption had no adverse effects. The supplementation did not increase the caloric intake compared with placebo, and the dietary constituents were similar between groups, except for the saturated fats, especially lauric acid. The analysis of blood pressure indicated absence of antihypertensive effect of EVCO alone or combined with physical training. Furthermore, no effects on blood pressure variability and oxidative stress were observed in the supplemented hypertensive patients. Thus, despite the results observed in pre-clinical studies, the current clinical study did not provide evidence to support the use of coconut oil as an adjuvant in the management of hypertension in humans.

Noninvasive exploration of Cardiac Autonomic Neuropathy by heart rate and blood pressure variability analysis in Type 2 Diabetic patients

Objectives:To determine the prevalence of asymptomatic cardiac autonomic neuropathy and its association with risk factors among patients with Type-2 diabetes mellitus (T2DM)Methods:The present case-control study was conducted at Department of Medicine, Civil Hospital, Dow University of Health Sciences (DUHS), Karachi, Pakistan during the period September` 2016 to May` 2017. After taking informed consent, subjects from both genders, 72 healthy controls and 72 clinically diagnosed T2DM diabetic patients, age between 30-65 years were selected by non-probability sampling technique. After taking medical history and demographics, Cardiac Autonomic Neuropathy (CAN) was identified by using Ewing`s cardiac autonomic reflex tests (CARTs) and association of risk factors was also investigated.Results:Severe CAN was identified in 13.9% of T2DM patients while in none of the healthy controls. HR response to deep breathing test was most sensitive (sensitivity= 90%) among all tests. The most common symptoms were Numbness (75.9%) and constipation (69%), resting heart rate and diabetes duration was significantly associated with DCAN.Conclusions:CAN was highly prevalent in diabetic population that may lead to nephropathy and retinopathy in future. It is highly recommended to use sensitive and simple CARTs in clinics for early detection and early treatment of CAN.

Daily inhalation of hydrogen gas has a blood pressure-lowering effect in a rat model of hypertension

A recent clinical study demonstrated that haemodialysis with a dialysate containing hydrogen (H2) improves blood pressure control in end-stage kidney disease. Herein, we examined whether H2 has a salutary effect on hypertension in animal models. We subjected 5/6 nephrectomised rats to inhalation of either H2 (1.3% H2 + 21% O2 + 77.7% N2) or control (21% O2 + 79% N2) gas mixture for 1 h per day. H2 significantly suppressed increases in blood pressure after 5/6 nephrectomy. The anti-hypertensive effect of H2 was also confirmed in rats in a stable hypertensive state 3 weeks after nephrectomy. To examine the detailed effects of H2 on hypertension, we used an implanted telemetry system to continuously monitor blood pressure. H2 exerted an anti-hypertensive effect not only during daytime rest, but also during night-time activities. Spectral analysis of blood pressure variability revealed that H2 improved autonomic imbalance, namely by suppressing the overly active sympathetic nervous system and augmenting parasympathetic nervous system activity; these effects co-occurred with the blood pressure-lowering effect. In conclusion, 1-h daily exposure to H2 exerts an anti-hypertensive effect in an animal model of hypertension.