Analysis of beat-to-beat blood pressure variability response to the cold pressor test in the offspring of hypertensive and normotensive parents

Arterial blood pressure monitoring in stroke cohorts: the impact of reduced sampling rates to optimise remote patient monitoring

OBJECTIVE

Remote patient monitoring (RPM) beat-to-beat blood pressure (BP) provides an opportunity to measure poststroke BP variability (BPV), which is associated with clinical stroke outcomes. BP sampling interval (SI) influences ambulatory BPV, but RPM BP SI optimisation research is limited. SI and RPM device capabilities require compromises, meaning SI impact requires investigation. Therefore, this study assessed healthy and stroke subtype BPV via optimised BP sampling, aiding sudden BP change identification and potentially assisting cardiovascular event (recurrent stroke) prediction.

METHODS

Leicester Cerebral Haemodynamic Database ischaemic [acute ischaemic stroke (AIS), n  = 68] and haemorrhagic stroke (intracerebral haemorrhage, n  = 12) patient and healthy control (HC, n  = 40) baseline BP data were analysed. Intrasubject and interpatient SD (SD i /SD p ) represented individual/population variability with synthetically altered SIs. Matched-filter approaches using cross-correlation function detected sudden BP changes.

RESULTS

At SIs between 1 and 180 s, SBP and DBP SD i staticised while SD p increased at SI < 30 s. Mean BP and HR SD i and SD p increased at SI < 60s. AIS BPV, normalised to SI1s, increased at SI30s (26%-131%) and SI120s (1%-274%). BPV increased concomitantly with SI. Cross-correlation analysis showed HC and AIS BP sudden change detection accuracy reductions with increasing SI. Positive BP deviation detection fell 48.48% (SI10s) to 78.79% (SI75s) in HC and 67.5% (SI10s) to 100% (SI75s) in AIS. Negative BP deviation detection fell 50% (SI10s) to 82.35% (SI75s) in HC and 52.27% (SI10s) to 95.45% (SI75s) in AIS.

CONCLUSION

Sudden BP change detection and BPV are relatively robust to SI increases within certain limits, but accuracy reductions generate unacceptable estimates, considerable within RPM device design. This research warrants further SI optimisation.

Influence of family history of hypertension on blood pressure and heart rate variability in young adults: a meta-analysis

PURPOUSE

This meta-analysis evaluates the impact of family history of hypertension (FHH + ) on blood pressure (BP) and heart rate variability (HRV) in young adults.

METHODS

Observational studies that evaluated adults (aged between 18 and 40 years) of both sexes, are without cardiometabolic disease diagnosis, are published in English, and are reporting on the influence of FHH + (father, mother, or both) on BP and HRV were included. In June 2021, we made a search of the electronic database MEDLINE (accessed by PubMed). Random-effects models were used, and data are reported as standardized mean difference and 95% confidence limits.

RESULTS

Thirty-eight studies with a total of 2025 individuals were included. Clinic systolic [3.13 mmHg (1.75-4.51)] and diastolic [2.85 mmHg (1.65-4.04)] BPs were higher ( P < 0.001) in individuals with an FHH + . Only 24-h systolic BP was higher [1.76 mmHg (0.05-3.47); P = 0.04] in individuals with an FHH + . As for HRV indices in time-domain, RMSSD: -7.00 ms (-10.75 to -3.26), SDNN: -13.93 ms (-23.56 to -4.30), and HF [-6.82 n. u. (-9.76 to -3.89)] were lower ( P < 0.05), and LF [4.78 ms (2.52-7.03)] and LF/HF ratio [0.32 (0.14-0.50)] were higher ( P < 0.001) in individuals with an FHH + .

CONCLUSION

FHH + negatively impacts BP and HRV in young adults.

Predictive Capacity of Beat-to-Beat Blood Pressure Variability for Cardioautonomic and Vascular Dysfunction in Early Metabolic Challenge

Diabetic patients present established cardiovascular disease at the onset of diagnostic metabolic symptoms. While premature autonomic and vascular deterioration considered risk factors for major cardiovascular complications of diabetes, present in initial stages of metabolic impairment, their early detection remains a significant challenge impeding timely intervention. In the present study, we examine the utility of beat-to-beat blood pressure variability (BPV) parameters in capturing subtle changes in cardiac autonomic and vascular control distinguishing between various risk categories, independent of the average BP. A rat model of mild hypercaloric (HC) intake was used to represent the insidious cardiovascular changes associated with early metabolic impairment. Invasive hemodynamics were used to collect beat-to-beat BP time series in rats of either sex with different durations of exposure to the HC diet. Linear (standard deviation and coefficient of variation) and nonlinear (approximate entropy, ApEn, and self-correlation of detrended fluctuation analysis, α) BPV parameters were calculated to assess the impact of early metabolic impairment across sexes and feeding durations. HC-fed male, but not female, rats developed increased fat:lean ratio as well as hyperinsulinemia. Unlike linear parameters, multivariate analysis showed that HC-fed rats possessed lower ApEn and higher α, consistent with early changes in heart rate variability and blunting of parasympathetic baroreceptor sensitivity, particularly in males. Moreover, logistic regression demonstrated the superiority of nonlinear parameters of diastolic BPV in predicting a prediabetic disease state. Our findings support the use of nonlinear beat-to-beat BPV for early detection of cardiovascular derangements in the initial stages of metabolic impairment.

Association between mental illness and blood pressure variability: a systematic review

Background

Mental illness represents a major global burden of disease worldwide. It has been hypothesised that individuals with mental illness have greater blood pressure fluctuations that lead to increased cardiovascular risk and target organ damage. This systematic review aims to (i) investigate the association between mental illness and blood pressure variability (BPV) and (ii) describe methods of BPV measurements and analysis which may affect pattern and degree of variability.

Methods

Four electronic databases were searched from inception until 2020. The quality assessment was performed using STROBE criteria. Studies were included if they investigated BPV (including either frequency or time domain analysis) in individuals with mental illness (particularly anxiety/generalised anxiety disorder, depression/major depressive disorder, panic disorder and hostility) and without hypertension. Two authors independently screened titles, abstracts and full texts. A third author resolved any disagreements.

Results

Twelve studies met the inclusion criteria. Three studies measured short-term BPV, two measured long-term BPV and seven measured ultra-short-term BPV. All studies related to short-term BPV using ambulatory and home blood pressure monitoring found a higher BPV in individuals with depression or panic disorder. The two studies measuring long-term BPV were limited to the older population and found mixed results. Mental illness is significantly associated with an increased BPV in younger and middle-aged adults. All studies of ultra-short-term BPV using standard cardiac autonomic assessment; non-invasive continuous finger blood pressure and heart rate signals found significant association between BPV and mental illness. A mixed result related to degree of tilt during tilt assessment and between controlled and spontaneous breathing were observed in patients with psychological state.

Conclusions

Current review found that people with mental illness is significantly associated with an increased BPV regardless of age. Since mental illness can contribute to the deterioration of autonomic function (HRV, BPV), early therapeutic intervention in mental illness may prevent diseases associated with autonomic dysregulation and reduce the likelihood of negative cardiac outcomes. Therefore, these findings may have important implications for patients' future physical health and well-being, highlighting the need for comprehensive cardiovascular risk reduction.

Longitudinal study on the effect of surgical weight loss on beat-to-beat blood pressure variability in patients undergoing bariatric surgery: a study protocol

INTRODUCTION

Alterations in linear and non-linear parameters of beat-to-beat blood pressure variability (BPV) have been shown to predict disease prognosis and distinguish between risk categories in various pathological conditions, independently of average blood pressure levels. Obesity places subjects at elevated risk of vascular diseases, including hypertension, resulting in serious cardiac, respiratory and cerebral events. However, little is known about the status of vascular dynamics in obese and morbidly obese adults.

METHODS AND ANALYSIS

In this present quasi-experimental longitudinal study, changes in beat-to-beat BPV, using continuous, non-invasive blood pressure monitoring, in obese subjects undergoing bariatric surgery are characterised. The capacity of linear and non-linear measures of BPV to detect differences between hypertensive, prehypertensive and normotensive obese subjects prebariatric and postbariatric surgery are tested. Additionally, potential correlations between beat-to-beat BPV and age, body mass index, gender and comorbidities will be investigated. In parallel, the impact of the unsteady fluctuations of beat-to-beat blood pressure on the dynamic stresses imparted by blood flow on blood vessel walls will be explored. We expect to find altered BPV profiles in hypertensive and prehypertensive subjects as compared with normotensive subjects. We also expect to see differential normalisation in BPV profiles between hypertensive, prehypertensive and normotensive subjects over time.

ETHICS AND DISSEMINATION

The study has been approved by the Institutional Review Board at the American University of Beirut (IRB ID: BIO-2018-0040). Study results will be made available to the public through publications in peer-reviewed journals and conference papers and/or presentations.

The recent effects of small dose of folic acid on lipoprotein-associated phospholipase A2 and systolic blood pressure variability in coronary heart disease patients with hyperhomocysteinemia: A single-center prospective cohort study

To Investigate the recent effects of small dose of folic acid on lipoprotein-associated phospholipase A2 (LP-PLA2) and systolic blood pressure variability in coronary heart disease (CHD) patients with hyperhomocysteinemia.In this prospective cohort study, a total of 167 CHD patients with hyperhomocysteinemia were consecutively enrolled, and they were divided into Group A (without folic acid intervention, n = 99), Group B (with 0.4 mg of folic acid intervention, n = 34), Group C (0.8 mg of folic acid intervention, n = 34). General information, fasting blood glucose, and blood lipid, folic acid, homocysteine, Lp-PLA2, and blood pressure variability were compared among 3 groups. The above indicators were reviewed after 3 months of treatment.There were no statistically significant differences of age, gender, blood pressure, incidence of type 2 diabetes mellitus, fasting blood glucose, folic acid, homocysteine, Lp-PLA2, total cholesterol, 3 acyl glycerin, apolipoprotein B, lipoprotein (a), high density lipoprotein cholesterol, and low density lipoprotein cholesterol were found among 3 groups (P > .05); however, after being treated for 3 months, there was statistically significant difference in folic acid among 3 groups (P < .05), there was statistically significant difference in apolipoprotein A between Group A and Group B (t = 0.505, P = .039), and also between Group A and Group C (t = 0.052, P = .017). There were statistically significant differences in Lp-PLA2 (t = 24.320, P = .016) and systolic blood pressure variability (t = 0.154, P = .018) between Group A and Group C.For CHD patients with hyperhomocysteinemia, the higher dose (0.8 mg) of folic acid supplement was beneficial for increasing the apolipoprotein A, reducing the Lp-PLA2, and improving the systolic blood pressure variation, which might help to improve the prognosis in these patients.

End-to-End Deep Learning Architecture for Continuous Blood Pressure Estimation Using Attention Mechanism

Blood pressure (BP) is a vital sign that provides fundamental health information regarding patients. Continuous BP monitoring is important for patients with hypertension. Various studies have proposed cuff-less BP monitoring methods using pulse transit time. We propose an end-to-end deep learning architecture using only raw signals without the process of extracting features to improve the BP estimation performance using the attention mechanism. The proposed model consisted of a convolutional neural network, a bidirectional gated recurrent unit, and an attention mechanism. The model was trained by a calibration-based method, using the data of each subject. The performance of the model was compared to the model that used each combination of the three signals, and the model with the attention mechanism showed better performance than other state-of-the-art methods, including conventional linear regression method using pulse transit time (PTT). A total of 15 subjects were recruited, and electrocardiogram, ballistocardiogram, and photoplethysmogram levels were measured. The 95% confidence interval of the reference BP was [86.34, 143.74] and [51.28, 88.74] for systolic BP (SBP) and diastolic BP (DBP), respectively. The R 2 values were 0.52 and 0.49, and the mean-absolute-error values were 4.06 ± 4.04 and 3.33 ± 3.42 for SBP and DBP, respectively. In addition, the results complied with global standards. The results show the applicability of the proposed model as an analytical metric for BP estimation.

HEMODYNAMIC RESPONSE AFTER CONCURRENT CROSS EXERCISE IN HYPERTENSIVE WOMEN

ABSTRACT Introduction: Systemic arterial hypertension is a disease that mainly affects women. Objective: This study aimed to verify the hypotensive effect and blood pressure reactivity in women submitted to a concurrent cross exercise (CC) session. Methods: Fifteen volunteers (54±3) performed aerobic exercise alternated with a series of weights exercises, for the analysis of blood pressure variation (by the oscillometric method) and pressure reactivity (by the Cold pressure test) before and after exercise. Results: The results demonstrated the occurrence of post-exercise hypotension in the systolic phase in the comparison between CC and C post-exercise (−11.65 mmHg). CC led to attenuation of 7mmHg and 4mmHg for SBP and DBP, respectively, in the blood pressure reactivity after one session. Conclusion: It is concluded that concurrent cross exercise ensures hypotension and positive reactivity of systolic blood pressure. Level of evidence II; Therapeutic studies-Investigating the results of treatment.

Novel blood pressure and pulse pressure estimation based on pulse transit time and stroke volume approximation

BACKGROUND

Non-invasive continuous blood pressure monitors are of great interest to the medical community due to their value in hypertension management. Recently, studies have shown the potential of pulse pressure as a therapeutic target for hypertension, but not enough attention has been given to non-invasive continuous monitoring of pulse pressure. Although accurate pulse pressure estimation can be of direct value to hypertension management and indirectly to the estimation of systolic blood pressure, as it is the sum of pulse pressure and diastolic blood pressure, only a few inadequate methods of pulse pressure estimation have been proposed.

METHODS

We present a novel, non-invasive blood pressure and pulse pressure estimation method based on pulse transit time and pre-ejection period. Pre-ejection period and pulse transit time were measured non-invasively using electrocardiogram, seismocardiogram, and photoplethysmogram measured from the torso. The proposed method used the 2-element Windkessel model to model pulse pressure with the ratio of stroke volume, approximated by pre-ejection period, and arterial compliance, estimated by pulse transit time. Diastolic blood pressure was estimated using pulse transit time, and systolic blood pressure was estimated as the sum of the two estimates. The estimation method was verified in 11 subjects in two separate conditions with induced cardiovascular response and the results were compared against a reference measurement and values obtained from a previously proposed method.

RESULTS

The proposed method yielded high agreement with the reference (pulse pressure correlation with reference R ≥ 0.927, diastolic blood pressure correlation with reference R ≥ 0.854, systolic blood pressure correlation with reference R ≥ 0.914) and high estimation accuracy in pulse pressure (mean root-mean-squared error ≤ 3.46 mmHg) and blood pressure (mean root-mean-squared error ≤ 6.31 mmHg for diastolic blood pressure and ≤ 8.41 mmHg for systolic blood pressure) over a wide range of hemodynamic changes.

CONCLUSION

The proposed pulse pressure estimation method provides accurate estimates in situations with and without significant changes in stroke volume. The proposed method improves upon the currently available systolic blood pressure estimation methods by providing accurate pulse pressure estimates.