Orthostatic hypertension: when pressor reflexes overcompensate

Orthostatic hypotension, orthostatic hypertension, and ambulatory blood pressure in patients with chronic kidney disease in CRIC

BACKGROUND

Orthostatic changes in blood pressure (BP), either orthostatic hypotension or orthostatic hypertension (OHTN), are common among patients with chronic kidney disease. Whether they are associated with unique out-of-office BP phenotypes is unknown.

METHODS

CRIC is a prospective, multicenter, observational cohort study of participants with CKD. BP measured at 2 min after standing and ambulatory BP monitoring (ABPM) were obtained on 1386 participants. Orthostatic hypotension was defined as a 20 mmHg drop in SBP or 10 mmHg drop in DBP when changing from seated to standing positions. Systolic and diastolic night-to-day ratio was also calculated. OHTN was defined as a 20 or 10 mmHg rise in SBP or DBP when changing from a seated to a standing position. White-coat effect (WCE) was defined as seated minus daytime ambulatory BP.

RESULTS

Of the 1386 participants (age: 58 ± 10 years, 44% female, 39% black), 68 had orthostatic hypotension and 153 had OHTN. Postural reduction in SBP or DBP was positively associated with greater systolic and diastolic WCE and systolic and diastolic night-to-day ratio. Orthostatic hypotension was positively associated with diastolic WCE (β = 3 [0.2, 5.9]). Diastolic OHTN was negatively associated with systolic WCE (β = -4 [-7.2, -0.5]) and diastolic WCE (β = -6 [-8.1, -4.2]).

CONCLUSION

Postural change in BP was associated with WCE and night-to-day-ratio. Orthostatic hypotension was positively associated with WCE and OHTN was negatively associated with WCE. These findings strengthen observations that postural changes in BP may associate with distinct BP patterns throughout the day. These observations are informative for subsequent research tailoring orthostatic hypotension and OHTN treatment to specific BP phenotypes.

Orthostatic hypotension and orthostatic hypertension are both associated with lower cognitive function: The S.AGES cohort

BACKGROUND

Blood pressure (BP) postural changes, both orthostatic hypotension (OHYPO) and orthostatic hypertension (OHYPER) are common in older adults. Few studies have investigated their association with cognition, particularly for OHYPER, an emerging cardiovascular risk factor. We aimed to assess the association between OHYPO, OHYPER and cognition in non-institutionalized older subjects.

METHODS

The S.AGES (Sujets ÂGES, Aged Subjects) cohort followed every 6 months for 3 years non-institutionalized subjects aged ≥65 years without dementia at inclusion, in France. OHYPO and OHYPER were respectively defined as a fall or an increase of ≥20 mmHg in systolic BP and/or ≥10 mmHg in diastolic BP after standing from a sitting position. Cognition was assessed using the Mini-Mental State Examination (MMSE). Linear mixed models were used for the analyses.

RESULTS

Among the 3170 subjects included (mean age 78 years, 56% women), 209 (6.5%) had OHYPO and 226 (7.1%) had OHYPER at baseline. After adjustment for demographics, cardiovascular risk factors and disease, seated SBP/DBP and BP lowering treatment, mean MMSE was 0.52 point lower in participants with OHYPER compared to those with normal BP postural changes (β adjusted [95% CI] = -0.52 [-0.96; -0.09], p = 0.02) and 0.50 point lower in participants with OHYPO compared to those with normal BP postural changes (β adjusted [95% CI] = -0.50 [-0.95; -0.06], p = 0.03). Sensitivity analyses showed a dose-response relationship between OHYPO and cognition.

CONCLUSION

Although the absolute differences in MMSE were small, both OHYPO and OHYPER were associated with lower cognition. Orthostatic BP measurements could help identify patients with risk of cognitive impairment. Further studies are needed to assess whether controlling orthostatic BP could be a promising interventional target in preserving cognition among older adults.

Variability of blood pressure response to orthostatism and reproducibility of orthostatic hypotension in hospitalized patients with acute ischemic stroke

OBJECTIVE

Orthostatic hypotension (OH) which diagnosis is based on the measurement of the blood pressure response to orthostatism (BPRO) is a common condition associated with adverse cerebrovascular and cognitive prognosis. It is likely that the single measurement might underestimate the true prevalence of OH. This study investigated the prevalence and reproducibility of the diagnosis of OH and related risk factors in hospitalized acute ischemic stroke (AIS) patients with multiple measurements.

MATERIALS AND METHODS

This study was a prospective cohort analysis of consecutive AIS patients admitted to the hospital. A total of 211 patients were included. BPRO was assessed five times at the same time on different days.

RESULTS

OH was found in 33 cases (15.6%) in the initial set of measurements of the first day. A cumulative diagnosis of OH after five BPRO tests was found in 75 cases (35.5%). The reproducibility of the diagnosis of OH was mild or poor. In patients with a cumulative diagnosis of OH, 29 (38.7%) patients had orthostatic hypertension (OHTN). In multivariate analysis, the Fazekas scale (odds radio = 1.28, 95% confidence interval (CI), 1.04-1.59, P  = 0.023) and extracranial carotid stenosis (≥70%) (odds radio = 3.64, 95% CI, 1.19-11.13, P  = 0.023) were independent risk factors for OH.

CONCLUSION

The reproducibility of OH is poor and the concurrent appearance of OH and OHTN is common in hospitalized AIS patients. Multiple measurements should be taken in hospitalized AIS patients when screening for OH especially patients with higher Fazekas scale and extracranial carotid stenosis (≥70%).

Prevalence of orthostatic hypertension and its association with cerebrovascular diagnoses in patients with suspected TIA and minor stroke

Purpose

We aimed to compare the rate of stroke, transient ischemic attack, and cerebrovascular disease diagnoses across groups of patients based on their orthostatic blood pressure response in a transients ischemic attack clinic setting.

Materials and Methods

We retrospectively analysed prospectively collected data from 3201 patients referred to a transient ischemic attack (TIA)/minor stroke outpatients clinic. Trained nurses measured supine and standing blood pressure using an automated blood pressure device and the patients were categorized based on their orthostatic blood pressure change into four groups: no orthostatic blood pressure rise, systolic orthostatic hypertension, diastolic orthostatic hypertension, and combined orthostatic hypertension. Then, four stroke physicians, who were unaware of patients' orthostatic BP response, assessed the patients and made diagnoses based on clinical and imaging data. We compared the rate of stroke, TIA, and cerebrovascular disease (either stroke or TIA) diagnoses across the study groups using Pearson's χ² test. The effect of confounders was adjusted using a multivariate logistic regression analysis.

Results

Cerebrovascular disease was significantly less common in patients with combined systolic and diastolic orthostatic hypertension compared to the "no rise" group [OR = 0.56 (95% CI 0.35–0.89]. The odds were even lower among the subgroups of patients with obesity [OR = 0.31 (0.12–0.80)], without history of smoking [OR 0.34 (0.15–0.80)], and without hypertension [OR = 0.42 (95% CI 0.19–0.92)]. We found no significant relationship between orthostatic blood pressure rise with the diagnosis of stroke. However, the odds of TIA were significantly lower in patients with diastolic [OR 0.82 (0.68–0.98)] and combined types of orthostatic hypertension [OR = 0.54 (0.32–0.93)]; especially in patients younger than 65 years [OR = 0.17 (0.04–0.73)] without a history of hypertension [OR = 0.34 (0.13–0.91)], and patients who did not take antihypertensive therapy [OR = 0.35 (0.14–0.86)].

Conclusion

Our data suggest that orthostatic hypertension may be a protective factor for TIA among younger and normotensive patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02600-1.

A Novel Methodology for the Synchronous Collection and Multimodal Visualization of Continuous Neurocardiovascular and Neuromuscular Physiological Data in Adults with Long COVID

Background: Reports suggest that adults with post-COVID-19 syndrome or long COVID may be affected by orthostatic intolerance syndromes, with autonomic nervous system dysfunction as a possible causal factor of neurocardiovascular instability (NCVI). Long COVID can also manifest as prolonged fatigue, which may be linked to neuromuscular function impairment (NMFI). The current clinical assessment for NCVI monitors neurocardiovascular performance upon the application of orthostatic stressors such as an active (i.e., self-induced) stand or a passive (tilt table) standing test. Lower limb muscle contractions may be important in orthostatic recovery via the skeletal muscle pump. In this study, adults with long COVID were assessed with a protocol that, in addition to the standard NCVI tests, incorporated simultaneous lower limb muscle monitoring for NMFI assessment. Methods: To conduct such an investigation, a wide range of continuous non-invasive biomedical sensing technologies were employed, including digital artery photoplethysmography for the extraction of cardiovascular signals, near-infrared spectroscopy for the extraction of regional tissue oxygenation in brain and muscle, and electromyography for assessment of timed muscle contractions in the lower limbs. Results: With the proposed methodology described and exemplified in this paper, we were able to collect relevant physiological data for the assessment of neurocardiovascular and neuromuscular functioning. We were also able to integrate signals from a variety of instruments in a synchronized fashion and visualize the interactions between different physiological signals during the combined NCVI/NMFI assessment. Multiple counts of evidence were collected, which can capture the dynamics between skeletal muscle contractions and neurocardiovascular responses. Conclusions: The proposed methodology can offer an overview of the functioning of the neurocardiovascular and neuromuscular systems in a combined NCVI/NMFI setup and is capable of conducting comparative studies with signals from multiple participants at any given time in the assessment. This could help clinicians and researchers generate and test hypotheses based on the multimodal inspection of raw data in long COVID and other cohorts.

Autonomic nervous system dysfunction in Wilson's disease - A systematic literature review

INTRODUCTION

In Wilson's disease (WD), copper accumulation can result in neurological manifestations, particularly extrapyramidal symptoms. There are some data that the autonomic nervous system (ANS) may also be affected, and we aimed to systematically review available studies evaluating ANS dysfunction in WD.

MATERIAL AND METHODS

We conducted a systematic review of the literature using the PubMed database (up to 31st August 2020), with search terms including "autonomic" and "function" and "Wilson's disease".

RESULTS

Fourteen studies, including 297 patients with neurological, hepatic or psychiatric forms of WD were retrieved. The most frequent methods used for ANS evaluation were orthostatic tests, which were performed in seven studies, with a number of other tests less frequently used. The incidence of ANS abnormalities ranged from ~8% to 79.2%, depending on the evaluation method. ANS abnormalities in patients with WD were often clinically asymptomatic. The features of dysautonomia were more common among patients with neurological symptoms and ANS abnormalities were more common in patients with severe brain injury. Studies confirmed both sympathetic and parasympathetic ANS impairment. The pathophysiology of ANS damage was not clear but may result from central, peripheral nervous system and direct cardiac involvement. Clear improvements were observed in four studies after anti-copper therapy initiation.

CONCLUSION

Both sympathetic and parasympathetic divisions of the ANS may be affected in WD. The observed ambiguities regarding ANS abnormalities in WD patients may arise from small study groups, differences in methodology, and a lack of comprehensive ANS evaluation; however, the results indicate that further studies are warranted.

Association of Pediatric Obstructive Sleep Apnea With Elevated Blood Pressure and Orthostatic Hypertension in Adolescence

Importance

Although pediatric guidelines have delineated updated thresholds for elevated blood pressure (eBP) in youth and adult guidelines have recognized obstructive sleep apnea (OSA) as an established risk factor for eBP, the relative association of pediatric OSA with adolescent eBP remains unexplored.

Objective

To assess the association of pediatric OSA with eBP and its orthostatic reactivity in adolescence.

Design, Setting, and Participants

At baseline of this population-based cohort study (Penn State Child Cohort) in 2000-2005, a random sample of 700 children aged 5 to 12 years from the general population was studied. A total of 421 participants (60.1%) were followed up in 2010-2013 after 7.4 years as adolescents (ages, 12-23 years). Data analyses were conducted from July 6 to October 29, 2020.

Main Outcomes and Measures

Outcomes were the apnea-hypopnea index (AHI) score, ascertained via polysomnography conducted in a laboratory; eBP measured in the seated position identified using guideline-recommended pediatric criteria; orthostatic hyperreactivity identified with BP assessed in the supine and standing positions; and visceral adipose tissue assessed via dual-energy x-ray absorptiometry.

Results

Among the 421 participants (mean [SD] age at follow-up, 16.5 [2.3] years), 227 (53.9%) were male and 92 (21.9%) were racial/ethnic minorities. A persistent AHI of 2 or more since childhood was longitudinally associated with adolescent eBP (odds ratio [OR], 2.9; 95% CI 1.1-7.5), while a remitted AHI of 2 or more was not (OR, 0.9; 95% CI 0.3-2.6). Adolescent OSA was associated with eBP in a dose-response manner; however, the association of an AHI of 2 to less than 5 among adolescents was nonsignificant (OR, 1.5; 95% CI, 0.9-2.6) and that of an AHI of 5 or more was approximately 2-fold (OR, 2.3; 95% CI, 1.1-4.9) after adjusting for visceral adipose tissue. An AHI of 5 or more (OR, 3.1; 95% CI, 1.2-8.5), but not between 2 and less than 5 (OR, 1.3; 95% CI, 0.6-3.0), was associated with orthostatic hyperreactivity among adolescents even after adjusting for visceral adipose tissue. Childhood OSA was not associated with adolescent eBP in female participants, while the risk of OSA and eBP was greater in male participants.

Conclusions and Relevance

The results of this cohort study suggest that childhood OSA is associated with adolescent hypertension only if it persists during this developmental period. Visceral adiposity explains a large extent of, but not all, the risk of hypertension associated with adolescent OSA, which is greater in male individuals.

Transient Orthostatic Hypertension During Head-Up Tilt Test in Young Adults: A Phenotype of Blood Pressure Variability

PURPOSE

The mechanisms underlying orthostatic hypertension (OHT) remain poorly understood. The authors evaluated the cardiovascular, cerebrovascular dynamics, and autonomic response to head-up tilt test (HUTT) in young adults with symptoms of orthostatic intolerance and transient OHT.

METHODS

Forty-four female subjects were included (34 ± 13 years old) and categorized in three groups after a 30-minute 70° passive HUTT: symptomatic patients with OHT (surge of systolic blood pressure ≥20 mm Hg for at least 5 minutes at any given time during HUTT), orthostatic intolerance (symptomatic patients without orthostatic blood pressure changes), and healthy asymptomatic control subjects.

RESULTS

At baseline, OHT patients had lower systolic blood pressure than orthostatic intolerance patients (103 ± 8 vs. 116 ± 10 mm Hg, p < 0.01) and lower baroreflex sensitivity than control subjects (15.8 ± 8.3 vs. 27.1 ± 11.7 ms/mm Hg, p = 0.01). On tilt, cardiac output decreased in OHT patients from 6.1 ± 1.4 L/minute during baseline to 5.2 ± 0.8 L/minute after 10 minutes of HUTT (p = 0.01). In OHT patients at 30 minutes of HUTT, sympathetic efferent heart activity was higher (77.4 ± 14.9 normalized units or nu) than orthostatic intolerant patients (63.5 ± 11.8 nu, p = 0.02) and control subjects (65.8 ± 11.2 nu, p = 0.05). Cerebrovascular resistance in OHT was higher than control subjects after 30 minutes (2.2 ± 0.8 vs. 1.6 ± 0.3 cm/second, respectively, p = 0.02).

CONCLUSIONS

This study demonstrates that transient OHT can occur at any given time during HUTT. These patients exhibit a decrease in cardiac output and a hyperadrenergic response to tilt.

Orthostatic Hypertension and Hypotension and Outcomes in CKD: The CRIC (Chronic Renal Insufficiency Cohort) Study

Rationale & Objective

There are limited data about the prevalence and prognostic significance of orthostatic hypo- and hypertension in patients with chronic kidney disease. The objective of this study is to determine the prevalence of orthostatic hypo- and hypertension in a cohort of patients with chronic kidney disease and examine their association with clinical outcomes.

Study Design

Prospective cohort study: Chronic Renal Insufficiency Cohort (CRIC) Study.

Setting & Population

7 clinical centers, participants with chronic kidney disease.

Exposures

Orthostatic hypotension (decline in systolic blood pressure [BP] > 20 mm Hg) and orthostatic hypertension (increase in systolic BP > 20 mm Hg) from seated to standing position.

Outcomes

Cardiovascular and kidney outcomes and mortality.

Analytical Approach

Logistic regression was used to determine factors associated with orthostatic hypo- and hypertension; Cox regression was used to examine associations with clinical outcomes.

Results

Mean age of study population (n = 3,873) was 58.1 ± 11.0 years. There was a wide distribution of change in systolic BP from seated to standing (from −73.3 to +60.0 mm Hg); 180 participants (4.6%) had orthostatic hypotension and 81 (2.1%) had orthostatic hypertension. Diabetes, reduced body mass index, and β-blocker use were independently associated with orthostatic hypotension. Black race and higher body mass index were independently associated with orthostatic hypertension. After a median follow-up of 7.9 years, orthostatic hypotension was independently associated with high risk for cardiovascular (HR, 1.12; 95% CI, 1.03-1.21) but not kidney outcomes or mortality. Orthostatic hypertension was independently associated with high risk for kidney (HR, 1.51; 96% CI, 1.14-1.97) but not cardiovascular outcomes or mortality.

Limitations

Orthostatic change in BP was ascertained at a single visit.

Conclusions

Orthostatic hypotension was independently associated with higher risk for cardiovascular outcomes, whereas orthostatic hypertension was associated with higher risk for kidney outcomes. These findings highlight the importance of orthostatic BP measurement in practice and the need for future investigation to understand the mechanisms and potential interventions to minimize the risk associated with orthostatic changes in BP.

Too much of a good thing: a case report of traumatic drop attacks and syncope due to orthostatic hypertension

Background

Orthostatic hypertension (OHT) is the clinical opposite to orthostatic hypotension and is an under-recognized and poorly understood clinical phenomenon. Patients may experience disabling symptoms such as dizziness, chest pain, and shortness of breath. In addition, OHT is associated with important clinical outcomes such as silent cerebral infarcts and cognitive decline.

Case summary

We present the case of a 67-year-old female who experienced frequent drop attacks with and without transient loss of consciousness causing various injuries. A range of standard diagnostic procedures did not yield an explanation for her symptoms but head-up tilt (HUT) testing showed OHT and induced most of her symptoms. Upon initiation of doxazosin, an alpha-blocking drug, she was free of symptoms and blood pressure response was normal on the repeat HUT test.

Discussion

To our knowledge, this is the first report of syncope due to OHT. Orthostatic hypertension is a heterogeneous condition and may occur in young, otherwise healthy individuals but also in older patients with cardiovascular comorbidities. It is thought that symptoms occur because of excessive venous pooling (causing a drop in cardiac output) or adrenergic hypersensitivity (resulting in cerebral vasoconstriction or acute rise in cardiac afterload). Since our patient had a marked response to an alpha-blocking agent, we think baroreflex hypersensitivity is the most likely cause of her complaints. Though syncope is probably rare, OHT should be regarded as a possible explanation of orthostatic symptoms.

Heart rate and blood pressure response improve the prediction of orthostatic cardiovascular dysregulation in persons with chronic spinal cord injury

Unstable blood pressure after spinal cord injury (SCI) is not routinely examined but rather predicted by level and completeness of injury (i.e., American Spinal Injury Association Impairment Scale AIS classification). Our aim was to investigate hemodynamic response to a sit-up test in a large cohort of individuals with chronic SCI to better understand cardiovascular function in this population. Continuous blood pressure and ECG were recorded from individuals with SCI (n = 159) and non-injured individuals (n = 48). We found orthostatic hypotension occurred within each level and AIS classification (n = 36). Moreover, 45 individuals with chronic SCI experienced a drop in blood pressure that did not meet the criteria for orthostatic hypotension, but was accompanied by dramatic increases in heart rate, reflecting orthostatic intolerance. A cluster analysis of hemodynamic response to a seated position identified eight distinct patterns of interaction between blood pressure and heart rate during orthostatic stress indicating varied autonomic responses. Algorithmic cluster analysis of heart rate and blood pressure is more sensitive to diagnosing orthostatic cardiovascular dysregulation. This indicates blood pressure instability cannot be predicted by level and completeness of SCI, and the consensus statement definition of orthostatic hypotension is insufficient to characterize the variability of blood pressure and heart rate responses during orthostatic stress. Both blood pressure and heart rate responses are needed to characterize autonomic function after SCI.

Addressing Orthostatic Hypotension in Heart Failure: Pathophysiology, Clinical Implications and Perspectives

Heart failure (HF)is a condition at high risk for orthostatic hypotension (OH)given the large proportion of patients at an advanced age and high burden of comorbidities contributing to OH, as well as a high prevalence of medications with neurovascular and volume modulating properties. Early identification of OH in HF seems to be crucial as OH can have an impact on patient symptoms, activity level and independence, be a marker of specific pathophysiological changes or be an indicator of need for personalized treatment. OH might contribute significantly to bad enough prognosis in HF, as, besides a risk of falls and cognitive decline, it was found to be associated with cardiovascular morbidity and mortality. In this review, we aimed to incentivize the routine use of orthostatic testing in HF, as well as stimulate future research in this field, which could lead to significant advances in the treatment and outcomes.

A practical guide to active stand testing and analysis using continuous beat-to-beat non-invasive blood pressure monitoring

PURPOSE

The average adult stands approximately 50-60 times per day. Cardiovascular responses evoked during the first 3 min of active standing provide a simple means to clinically assess short-term neural and cardiovascular function across the lifespan. Clinically, this response is used to identify the haemodynamic correlates of patient symptoms and attributable causes of (pre-)syncope, and to detect autonomic dysfunction, variants of orthostatic hypotension, postural orthostatic tachycardia syndrome and orthostatic hypertension.

METHODS

This paper provides a set of experience/expertise-based recommendations detailing current state-of-the-art measurement and analysis approaches for the active stand test, focusing on beat-to-beat BP technologies. This information is targeted at those interested in performing and interpreting the active stand test to current international standards.

RESULTS

This paper presents a practical step-by-step guide on (1) how to perform active stand measurements using beat-to-beat continuous blood pressure measurement technologies, (2) how to conduct an analysis of the active stand response and (3) how to identify the spectrum of abnormal blood pressure and heart rate responses which are of clinical interest.

CONCLUSION

Impairments in neurocardiovascular control are an attributable cause of falls and syncope across the lifespan. The simple active stand test provides the clinician with a powerful tool for assessing individuals at risk of such common disorders. However, its simplicity belies the complexity of its interpretation. Care must therefore be taken in administering and interpreting the test in order to maximise its clinical benefit and minimise its misinterpretation.

The association between orthostatic blood pressure changes and subclinical target organ damage in subjects over 60 years old

Background

Although recent studies have indicated that both orthostatic hypotension and orthostatic hypertension independently predict cardiovascular events, the underlying mechanisms are still controversial. The aim of the study was to investigate the relationships between orthostatic changes and organ damage in subjects over 60 years old.

Methods

This is a prospective observational cohort study. One thousand nine hundred and ninety-seven subjects over 60 years old were enrolled. Participants were grouped according to whether they had a drop ≥ 20 mmHg in systolic or ≥ 10 mmHg in diastolic BP (orthostatic hypotension), an increase in mean orthostatic systolic blood pressure ≥ 20 mm Hg (orthostatic hypertension), or normal changes within 3 min of orthostatism. Multiple regression modeling was used to investigate the relationship between orthostatic hypotension, orthostatic hypertension and subclinical organ damage with adjustment for confounders.

Results

Orthostatic hypotension and orthostatic hypertension were found in 461 (23.1%) and 189 (9.5%) participants, respectively. Measurement of carotid intima-media thickness (IMT), brachial-ankle pulse wave velocity (baPWV), clearance of creatinine, and microalbuminuria were associated with orthostatic hypotension; measurement of IMT and baPWV were associated with orthostatic hypertension in a cruse model. After adjustment, IMT [odds ratio (OR), 95% confidence interval (CI) per one-SD increment: 1.385, 1.052–1.823; P = 0.02], baPWV (OR = 1.627, 95% CI: 1.041–2.544; P = 0.033) and microalbuminuria (OR = 1.401, 95% CI: 1.002–1.958; P = 0.049) were still associated with orthostatic hypotension, while orthostatic hypertension was only associated with IMT (OR = 1.730, 95% CI: 1.143–2.618; P = 0.009).

Conclusions

Orthostatic hypotension seems to be independently correlated with increased carotid atherosclerosis, arterial stiffness and renal damage in subjects over 60 years old. Orthostatic hypertension correlates with carotid atherosclerosis only.

Cerebral Perfusion Monitoring Using Near-Infrared Spectroscopy During Head-Up Tilt Table Test in Patients With Orthostatic Intolerance

The head-up tilt table test (HUT) is one of the primary clinical examinations for evaluating orthostatic intolerance (OI). HUT can be divided into three phases: dynamic tilt phase (supine to tilt up), static tilt phase (remain tilted at 70°), and post tilt phase (tilt down back to supine position). Commonly, blood pressure (BP) and heart rate (HR) are monitored to observe for OI symptoms, but are indirect measurements of cerebral perfusion and can lead to inaccurate HUT evaluation. In this study, we implemented a 108-channel near-infrared spectroscopy (NIRS) probe to characterize HUT performance by monitoring cerebral hemodynamic changes for healthy controls (HCs), OI patients with normal HUT results, and OI patients with positive HUT results: vasovagal syncope (VS), postural orthostatic tachycardia syndrome (POTS), orthostatic hypotension (OH), and orthostatic hypertension (OHT). By the end of the static tilt phase, OI patients typically did not show a complete recovery back to baseline cerebral oxygenation and total blood volume compared to HCs. We characterized the return to cerebral homeostasis by polynomial fitting total blood volume changes and determining the inflection point. The OI patients with normal HUT results, VS, OH, or OHT showed a delay in the return to cerebral homeostasis compared to the HC group during HUT.

Orthostatic hypertension: From pathophysiology to clinical applications and therapeutic considerations

Orthostatic hypertension (OHT), that is, sustained increase in blood pressure after standing, is an increasingly recognized cardiovascular disorder having been examined in much fewer studies compared with orthostatic hypotension (OH). However, in both OHT and OH, dysfunction of the autonomous nervous system is considered to be the primary pathophysiological disturbance, while significant associations with essential hypertension have been observed. Although in many studies OHT has been related to subclinical or clinical target organ damage, there is also evidence denying such an association. Because OHT is defined variably across different studies, the comparison of relevant outcomes is at least problematic. Since evidence about OHT treatment is exclusively based on limited non-randomized studies, no specific recommendations have been developed. Therefore, both the prognostic role and the clinical significance of OHT remain largely undefined. The aim of the present review is to summarize the available evidence regarding the definition, diagnosis, pathophysiology, prognostic role and treatment of OHT and highlight potential clinical implications of this underestimated condition.

Hypertension Management at Older Age: An Update

Hypertension is a risk factor for cardiovascular morbidity and mortality with increasing prevalence with age, whose treatment is associated with benefits over fatal and non-fatal cardiovascular events even later in life. However, there are persistent concerns on the short- and long-term weighted benefits of treating hypertension in the very old, particularly in those with specific clinical features. In fact, a broad range of clinical scenarios can be observed at older ages, spanning from the healthy to the frailest patient, and hypertension clinical trials have traditionally excluded the latter, thus preventing the unconditioned application to these patients of the same recommendations as in younger ages. Persistent issues regarding high blood pressure management in the very old adult are mainly related to treatment threshold and targets, which have been differently addressed by American and European guidelines. Herein, we will examine the challenges related to high blood pressure treatment in healthy and frail older and very old adults. We will discuss the evidence behind current recommendations. Finally, we will recapitulate the recommended treatment options for high blood pressure in these patients in the light of the most recent guidelines.

Ambulatory blood pressure monitoring in children suffering from orthostatic hypertension

BACKGROUND

It is particularly important to utilize appropriate blood pressure measurement methods to evaluate the changes of orthostatic hypertension (OHT) for children, and this study was designed to analyze the blood pressure type in OHT children with 24 h semiautomatic ambulatory blood pressure monitoring.

METHODS

Children who were diagnosed by head-up tilt table test as OHT patients (OHT group) and treated or hospitalized in the syncope specialist outpatient unit of the Second Xiangya Hospital of Central South University mainly for syncope or pre-syncope with unknown causes during the October, 2009 to September, 2013 were recruited in the study. Healthy children that came to the hospital for physical examination at the same time period according to age and sex were matched as control group. Semiautomatic ambulatory blood pressure monitoring of every child was recorded. The differences of daytime systolic (diastolic) pressure and night systolic (diastolic) pressure were calculated, and the average systolic pressure and diastolic pressure of the entire day, daytime and night were also calculated, respectively.

RESULTS

There were 23 boys and 17 girls in OHT group, aging (11.5 ± 1.9) years. There were 22 boys and 18 girls in the control group, aged (10.6 ± 2.4) years. The difference of daytime systolic pressure and night systolic pressure of the control group was higher than that of OHT group, while the average systolic pressure of the whole day, the average diastolic pressure of the whole day, the daytime average systolic pressure, the daytime average diastolic pressure, the night average systolic pressure and the night average diastolic pressure were higher than that of the control group (P > 0.05). The difference of daytime diastolic pressure and night diastolic pressure of the control group was higher than that of OHT group (P > 0.05). Most children of the OTH group had non-dipper blood pressure type (72.5%), while most children of the control group had a dipper blood pressure type (55.0%). In addition, the time domain SDNN and SDANN in the OHT group were higher than those in the control group (P < 0.01). And, the indicators including TP, ULF, VLF, and LF/HF were higher in the OHT group, when compared with control group (P < 0.01). Besides, in terms of subgroup analysis within the OHT group, the age difference between boys and girls was not statistically significant (P > 0.05). When compared with grils, the time domain SDNN increased (P = 0.003), and the frequency index TP, ULF, and VLF increased in boy group (P < 0.05).

CONCLUSION

OHT Children's autonomic nervous system showed dysfunction, and differences of systolic blood pressure between day and night were much lower than those of healthy children, and the main blood type was non-dipper blood pressure with circadian rhythm disappearing.

Impact of variations in blood pressure with orthostatism on mortality: the HOMO study

OBJECTIVE

The aim of this study was to determine the impact of orthostatic hypotension (OH) and orthostatic hypertension (OHT) on all-cause mortality.

PATIENTS AND METHODS

A total of, 1176 adults from the community over 18 years of age were included in this ambispective study. The mean follow-up was 9.4 years. OH and OHT were defined as a decrease or an increase, respectively, in systolic blood pressure (BP) of at least 20 mmHg and/or diastolic BP of at least 10 mmHg from sitting to standing position at 1 and/or 3 min after standing. The impact of systolic or diastolic OH and systolic or diastolic OHT at 1 and 3 min after standing was also analyzed separately.

RESULTS

In total, 135 individuals died during the follow-up. Neither OH [hazard ratio (HR) 1.23; 95% confidence interval (CI): 0.72-2.10] nor OHT (HR 0.90; 95% CI: 0.59-1.38) was associated with all-cause mortality in the adjusted models. In contrast, systolic OHT at 3 min (HR 2.31; 95% CI: 1.14-4.68) was independently associated with global mortality.

CONCLUSION

Systolic OHT at 3 min is associated with all-cause mortality. The determination of this parameter could add valuable prognostic information during the routine examination of patients.

Body Size Predicts Cardiac and Vascular Resistance Effects on Men's and Women's Blood Pressure

Key Points Summary We report how blood pressure, cardiac output and vascular resistance are related to height, weight, body surface area (BSA), and body mass index (BMI) in healthy young adults at supine rest and standing.Much inter-subject variability in young adult's blood pressure, currently attributed to health status, may actually result from inter-individual body size differences.Each cardiovascular variable is linearly related to height, weight and/or BSA (more than to BMI).When supine, cardiac output is positively related, while vascular resistance is negatively related, to body size. Upon standing, the change in vascular resistance is positively related to size.The height/weight relationships of cardiac output and vascular resistance to body size are responsible for blood pressure relationships to body size.These basic components of blood pressure could help distinguish normal from abnormal blood pressures in young adults by providing a more effective scaling mechanism. Introduction: Effects of body size on inter-subject blood pressure (BP) variability are not well established in adults. We hypothesized that relationships linking stroke volume (SV), cardiac output (CO), and total peripheral resistance (TPR) with body size would account for a significant fraction of inter-subject BP variability. Methods: Thirty-four young, healthy adults (19 men, 15 women) participated in 38 stand tests during which brachial artery BP, heart rate, SV, CO, TPR, and indexes of body size were measured/calculated. Results: Steady state diastolic arterial BP was not significantly correlated with any index of body size when subjects were supine. However, upon standing, the more the subject weighed, or the taller s/he was, the greater the increase in diastolic pressure. Systolic pressure strongly correlated with body weight and height both supine and standing. Diastolic and systolic BP were more strongly related to height, weight and body surface area than to body mass index. When supine: lack of correlation between diastolic pressure and body size, resulted from the combination of positive SV correlation and negative TPR correlation with body size. The positive systolic pressure vs. body size relationship resulted from a positive SV vs. height relationship. In response to standing: the positive diastolic blood pressure vs. body size relationship resulted from the standing-induced, positive increase in TPR vs. body size relationship. The relationships between body weight or height with SV and TPR contribute new insight into mechanisms of BP regulation that may aid in the prediction of health in young adults by providing a more effective way to scale BP with body size.

Orthostatic hypertension in normotensive type 2 diabetics: What characteristics?

AIM OF THE STUDY

We aimed to determine the prevalence of orthostatic hypertension (OHT) in normotensive, newly diagnosed type 2 diabetics, to assess clinical, biological characteristics of those patients and evaluate the evolution of their blood pressure, after one year of follow-up.

MATERIALS AND METHODS

It is an observational, prospective, cohort study, on 108 normotensive, newly diagnosed diabetics, 40 men and 68 women aged from 40 to 70 ans. OHT was defined as an increase of systolic blood pressure (SBP) ≥20mmHg and/or diastolic blood pressure (DBP) ≥10mmHg, after 1 and 2min of standing from supine position. Arterial hypertension and metabolic syndrome were respectively defined according to WHO and AHA 2009 guidelines. Clinical and biological data were collected for all patients. They had a screening for diabetic complications and a follow-up during one year. Statistical analysis was performed with Epi-Info 6.04.

RESULTS

We found OHT in 22 patients (20.4%). Patients with OHT had a higher SBP at lying position (P=0.029), a higher waist circumference (P=0.022) and LDL (P=0.041). They had more frequently obesity (P=0.036) left ventricular hypertrophy (P=0.024), metabolic syndrome (P=0.042) and cerebrovascular events (P=0.050) when compared with those with normal blood pressure response to orthostasis. One year after follow-up, the prevalence of permanent hypertension was significantly higher in the OHT group (P=0.0008).

CONCLUSION

Our study suggests that OHT is associated with insulin resistance syndrome and onset of sustained arterial hypertension in normotensive, newly diagnosed diabetics.

Giant oesophageal leiomyoma causing severe hypertension

Leiomyoma is the most common oesophageal tumour and is symptomatic in about half of the patients. Dysphagia is the most common symptom. A 41-year-old woman presented with recent onset of severe orthostatic hypertension. During the cardiological work-up, a mediastinal mass was found at transthoracic echocardiogram. Further investigation (upper gastrointestinal endoscopy, endoscopic ultrasonography, CT scan and cardiac MRI) confirmed the diagnosis of a large oesophageal submucosal mass compressing the supradiaphragmatic inferior vena cava. The mass was resected through a minimally invasive right thoracoscopic approach with complete relief of symptoms and compression on the vena cava.

Abnormal orthostatic blood pressure control among subjects with lacunar infarction

Introduction

Hypertension is a recognised risk factor for lacunar stroke. However, their association has been evaluated using static blood pressure (BP) assessment in supine or sitting position alone. We hypothesised that impaired dynamic (orthostatic) BP control may associate with lacunar strokes.

Patients and methods

Consecutive subjects with mitral regurgitation (MR) confirmed, lacunar strokes were compared with two control groups. Firstly "normal", age and sex matched, population controls (1:3 ratio) and then 'at risk' controls matched for age, sex, hypertension history and antihypertensive medication (1:2 ratio). Orthostatic BP control was assessed by active stand tests with continuous, phasic, beat-to-beat BP measurement.

Findings

Thirty-six subjects (mean 69.9 years) were compared with 108 controls in group 1 and 72 in group 2. Prevalence of syncope was higher among those with lacunar stroke (cases: 44.4%, group 1: 17.6%, p = 0.003, group 2: 12.5%, p = 0.0004, Fisher's exact). Mean baseline systolic BP (SBP) was significantly higher in cases (cases: 150 mm Hg, group 1: 140 mm Hg, p = 0.03, group 2: 143 mm Hg, p = 0.1). Ten seconds after standing, SBP dropped significantly less in cases (cases: -14.1 mm Hg, group 1: -31.4 mm Hg, p < 0.0005, group 2: -27.3 mm Hg, p = 0.001, t test). Diastolic BP also fell significantly less in cases. Cases' SBP and DBP recovered to, then persistently overshot baseline levels.

Discussion and conclusion

Subjects with MR-defined lacunar stroke, of likely small vessel aetiology, exhibit orthostatic hypertension compared with population norms.

Orthostatic Changes in Blood Pressure and Cognitive Status in the Elderly

We studied a cohort of 1408 older subjects to explore whether postural changes in blood pressure (BP; defined as orthostatic hypo- or hypertension) can predict the onset of cognitive deterioration. Orthostatic hypotension was defined as a drop of 20 mm Hg in systolic or 10 mm Hg in diastolic BP and orthostatic hypertension as a rise of 20 mm Hg in systolic BP. Orthostatic BP values were grouped into quintiles for secondary analyses. Two cognitive assessments were considered: (1) cognitive impairment, that is, Mini-Mental State Examination scores ≤24/30, and (2) cognitive decline (CD), that is, a 3-point decrease in Mini-Mental State Examination score from the baseline to the follow-up. At the baseline, the prevalence of orthostatic hypotension and hypertension was 18.3% and 10.9%, respectively. At the follow-up (4.4±1.2 years), 286 participants were found cognitively impaired and 138 had a CD. Using logistic regression analysis adjusted for potential baseline confounders, participants with orthostatic hypertension were at significantly higher risk of CD (odds ratio =1.50; 95% confidence intervals =1.26–1.78). Neither orthostatic hypotension nor orthostatic hypertension raised the risk of developing a cognitive impairment. Using quintiles of orthostatic BP values, we found that both decreases and increases in systolic and diastolic BP raised the risk of CD, but not of cognitive impairment. In conclusion, we found that orthostatic hypertension predicts the onset of CD, but not of cognitive impairment in the elderly, whereas orthostatic hypotension predicts neither of these conditions. Further studies are needed to confirm our findings.

Cerebral Blood Flow, Heart Rate, and Blood Pressure Patterns during the Tilt Test in Common Orthostatic Syndromes

Objective. The head-up tilt test is widely used for evaluation of orthostatic intolerance. Although orthostatic symptoms usually reflect cerebral hypoperfusion, the cerebral blood flow velocity (CBFv) profile in orthostatic syndromes is not well described. This study evaluated CBFv and cardiovascular patterns associated with the tilt test in common orthostatic syndromes. Methods. This retrospective study analyzed the tilt test of patients with history of orthostatic intolerance. The following signals were recorded: ECG, blood pressure, CBFv using transcranial Doppler, respiratory signals, and end tidal CO2. Results. Data from 744 patients were analyzed. Characteristic pattern associated with a particular orthostatic syndrome can be grouped into abnormalities predominantly affecting blood pressure (orthostatic hypotension, orthostatic hypertension syndrome, vasomotor oscillations, and neurally mediated syncope-cardioinhibitory, vasodepressor, and mixed), cerebral blood flow (orthostatic hypoperfusion syndrome, primary cerebral autoregulatory failure), and heart rate (tachycardia syndromes: postural tachycardia syndrome, paroxysmal sinus tachycardia, and inappropriate sinus tachycardia). Psychogenic pseudosyncope is associated with stable CBFv. Conclusions. The tilt test is useful add-on in diagnosis of several orthostatic syndromes. However diagnostic criteria for several syndromes had to be modified to allow unambiguous pattern classification. CBFv monitoring in addition to blood pressure and heart rate may increase diagnostic yield of the tilt test.

Diastolic orthostatic hypertension and cardiovascular prognosis in type 2 diabetes: a prospective cohort study

BACKGROUND

In patients with type 2 diabetes, the prognostic impact of an orthostatic rise in blood pressure is not known. Therefore, the aim of this study was to determine the prognostic implications of the diastolic orthostatic blood pressure response in a cohort of patients with type 2 diabetes. We also evaluated associations between different orthostatic blood pressure responses and markers of subclinical cardiovascular organ damage.

METHODS

Office blood pressures were measured in the sitting and in the standing position in 749 patients with type 2 diabetes who participated in the CARDIPP study (Cardiovascular Risk factors in Patients with Diabetes-a Prospective study in Primary care). Diastolic orthostatic hypertension was defined as a rise of diastolic blood pressure ≥10 mmHg and diastolic orthostatic hypotension was defined as a drop of diastolic blood pressure ≥10 mmHg. Recruitment took place between the years 2005-2008, and patients were followed until any of the primary outcome events (cardiovascular death or hospitalization for either myocardial infarction or stroke) occurred or until December 31st, 2014. Measurements of aortic pulse wave velocity and of carotid intima-media thickness were performed at base-line.

RESULTS

Diastolic orthostatic hypertension was found in 140 patients (18.7 %) and was associated with significantly lower risk of cardiovascular events (crude hazard ratio compared with patients with normal systolic and diastolic orthostatic blood pressure response: 0.450, 95 % C.I. 0.206-0.987, P = 0.046). Diastolic orthostatic hypotension was found in 31 patients (4.1 %) and was associated with higher values for aortic pulse wave velocity and carotid intima-media thickness, compared with patients with normal systolic and diastolic orthostatic blood pressure response.

CONCLUSIONS

Diastolic orthostatic hypertension is common in patients with type 2 diabetes, and may be a novel marker for decreased cardiovascular risk in these patients.

The association between orthostatic hypertension and all-cause mortality in hospitalized elderly persons

Background

Little is known about the prevalence of orthostatic hypertension (OHT) and its effect on long-term mortality in the elderly. We evaluated the prevalence of OHT and its effect on mortality in hospitalized elderly patients.

Methods

Out of 1852 patients admitted between 31/12/1999 and 31/12/2000 to an acute geriatric ward, 474 patients (48% males) with a mean age of 81.5 ± 6.8 years were enrolled in this study. Blood pressure (BP) was measured three times during the day in a supine and standing position. Patients with at least one increase in systolic or diastolic BP levels upon standing were diagnosed with OHT. Medical history, physical examination and laboratory parameters were retrieved from the medical records. Mortality data until 18^th June 2014 were retrieved from the computerized system of the Ministry of the Interior.

Results

Four hundred and seven patients (86%) were diagnosed with OHT. Those without OHT had a lower body mass index and were more likely males, smokers, had a higher rate of Parkinson's disease and less congestive heart failure compared with those with OHT. Patients with OHT had a better survival rate than those without OHT (P = 0.024). Hazard ratios (HRs) for mortality in those with OHT adjusted to age and multiple risk factors were: 0.67 [95% confidence interval (CI): 0.51−0.87] and 0.73 (95% CI: 0.55−0.97), respectively; a similar tendency was noticed in a sensitivity analysis by gender.

Conclusion

Hospitalized elderly patients with OHT had a better survival rate than those without OHT.

The circadian rhythm of syncopal episodes in patients with neurally mediated syncope

OBJECTIVE

To explore the circadian rhythm of neurally mediated syncope (NMS).

METHODS

411 patients with NMS (165 males and 246 females aged from 3 to 68years) were included in the study. All subjects underwent head-up tilt test (HUTT) and were carefully asked about the number of syncopal attacks and the periods (morning 06:00am-12:00am, afternoon 12:00am-18:00pm, evening 18:00pm-24:00pm, night 00:00am-06:00am) in which episodes occurred in.

RESULTS

(1) Syncopal attacks of all patients tended to occur in the morning (P=0.010); there was a statistical difference in the frequency of episodes in four periods through the day in HUTT positive patients (P=0.001), but there was no significant change of episodes within a day in HUTT negative group; and there was no statistical difference in circadian syncope distribution between HUTT negative and HUTT positive group or among patients with different HUTT responses (the orthostatic hypotension (OH) and orthostatic hypertension (OHT) patients were excluded). (2) The syncopal attacks of morning hours occurred more in males than females, but the episodes in the evening occurred more in females than males (P=0.034). (3) The younger the patients were, the chance of syncopal attacks in the morning increased; the older the patients were, they may have more episodes at night (P<0.001).

CONCLUSIONS

A distinct circadian variation in the frequency of syncopal episodes exists, with a peak in the morning, and there were statistical differences in circadian rhythm of syncopal episodes regarding gender and age.

Orthostatic hypertension: An underestimated cause of orthostatic intolerance

OBJECTIVE

To investigate the frequency and mechanism of orthostatic hypertension (OHT) in patients with orthostatic intolerance.

METHODS

We retrospectively reviewed 1033 consecutive case series of orthostatic intolerance that underwent autonomic function tests including a head-up tilt test. OHT was defined as a paradoxical orthostatic increase in systolic blood pressure (BP) of at least 20 mmHg during the tilt. We collected autonomic parameters during the standardized autonomic function tests, which included the beat-to-beat derived hemodynamic parameters during the tilt table test and compared them with age and sex-matched normal controls and the orthostatic hypotension (OH) group with orthostatic symptoms.

RESULTS

We identified 38 (3.7%) patients who showed OHT during the tilt. The increase in mean systolic BP during the tilt was 26.5 mmHg. Approximately 87% (33/38) of the OHT patients showed an increase in total peripheral resistance during the tilt. The mean increase in total peripheral resistance from a supine baseline was significantly higher in OHT patients compared to normal controls, but the OH group showed a decrease in mean total peripheral resistance during the tilt.

CONCLUSION

A select few patients with orthostatic dizziness can show OHT during the tilt and they have signs of increased peripheral resistance.

SIGNIFICANCE

OHT may be considered in the differential diagnosis of orthostatic intolerance.

Evidence for a Prognostic Role of Orthostatic Hypertension on Survival in a Very Old Institutionalized Population

In old individuals, regulation of blood pressure during postural changes is impaired. Several studies have assessed the clinical impact of orthostatic hypotension (OHypoT) during the aging process. By contrast, the prevalence and prognostic role of the increase in blood pressure in upright position (orthostatic hypertension, OHyperT) in old adults remain unknown. We investigated the association of OHyperT with cardiovascular morbidity and mortality in a population of old institutionalized subjects. A 2-year follow-up longitudinal study was conducted on 972 subjects (mean age [SD] 88 [5]) from the PARTAGE (Predictive Values of Blood Pressure and Arterial Stiffness in Institutionalized Very Aged Population) study, able to maintain a standing position. OHyperT was defined as an increase in systolic blood pressure ≥20 mm Hg during the first and third minute of standing. Three groups of subjects were compared: orthostatic normotension (n=540), OHypoT (n=157), and OHyperT (n=275). OHyperT prevalence (28%) was higher than OHypoT (16%). Sitting systolic blood pressure was higher in OHypoT compared with orthostatic normotension and OHyperT groups (146 [23] versus 136 [21] and 136 [20] mm Hg, respectively, P<0.001). The OHyperT group was associated with a greater risk of cardiovascular morbidity and mortality than orthostatic normotension (hazard ratio 1.51 [1.09-2.08], P<0.01) and remained unchanged after adjustment for age, sex, sitting systolic blood pressure, and comorbidities. No difference in cardiovascular morbidity and mortality was observed between OHyperT and OHypoT groups. In conclusion, in a old frail population, the increase in systolic blood pressure during upright position occurs frequently and is associated with higher cardiovascular morbidity and mortality independently of sitting blood pressure levels and major comorbidities. Health professional should take into account not only the decrease but also the increase in blood pressure when standing up.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00901355.

Blood flow restriction training and the exercise pressor reflex: a call for concern

Blood flow restriction (BFR) training (also known as Kaatsu training) is an increasingly common practice employed during resistance exercise by athletes attempting to enhance skeletal muscle mass and strength. During BFR training, blood flow to the exercising muscle is mechanically restricted by placing flexible pressurizing cuffs around the active limb proximal to the working muscle. This maneuver results in the accumulation of metabolites (e.g., protons and lactic acid) in the muscle interstitium that increase muscle force and promote muscle growth. Therefore, the premise of BFR training is to simulate and receive the benefits of high-intensity resistance exercise while merely performing low-intensity resistance exercise. This technique has also been purported to provide health benefits to the elderly, individuals recovering from joint injuries, and patients undergoing cardiac rehabilitation. Since the seminal work of Alam and Smirk in the 1930s, it has been well established that reductions in blood flow to exercising muscle engage the exercise pressor reflex (EPR), a reflex that significantly contributes to the autonomic cardiovascular response to exercise. However, the EPR and its likely contribution to the BFR-mediated cardiovascular response to exercise is glaringly missing from the scientific literature. Inasmuch as the EPR has been shown to generate exaggerated increases in sympathetic nerve activity in disease states such as hypertension (HTN), heart failure (HF), and peripheral artery disease (PAD), concerns are raised that BFR training can be used safely for the rehabilitation of patients with cardiovascular disease, as has been suggested. Abnormal BFR-induced and EPR-mediated cardiovascular complications generated during exercise could precipitate adverse cardiovascular or cerebrovascular events (e.g., cardiac arrhythmia, myocardial infarction, stroke and sudden cardiac death). Moreover, although altered EPR function in HTN, HF, and PAD underlies our concern for the widespread implementation of BFR, use of this training mechanism may also have negative consequences in the absence of disease. That is, even normal, healthy individuals performing resistance training exercise with BFR are potentially at increased risk for deleterious cardiovascular events. This review provides a brief yet detailed overview of the mechanisms underlying the autonomic cardiovascular response to exercise with BFR. A more complete understanding of the consequences of BFR training is needed before this technique is passively explored by the layman athlete or prescribed by a health care professional.

A cross-sectional study on upright heart rate and BP changing characteristics: basic data for establishing diagnosis of postural orthostatic tachycardia syndrome and orthostatic hypertension

OBJECTIVE

We aimed to determine upright heart rate and blood pressure (BP) changes to suggest diagnostic criteria for postural orthostatic tachycardia syndrome (POTS) and orthostatic hypertension (OHT) in Chinese children.

METHODS

In this cross-sectional study, 1449 children and adolescents aged 6-18 years were randomly recruited from two cities in China, Kaifeng in Henan province and Anguo in Hebei province. They were divided into two groups: 844 children aged 6-12 years (group I) and 605 adolescents aged 13-18 years (group II). Heart rate and BP were recorded during an active standing test.

RESULTS

95th percentile (P(95)) of δ heart rate from supine to upright was 38 bpm, with a maximum upright heart rate of 130 and 124 bpm in group I and group II, respectively. P(95) of δ systolic blood pressure (SBP) increase was 18 mm Hg and P(95) of upright SBP was 132 mm Hg in group I and 138 mm Hg in group II. P(95) of δ diastolic blood pressure (DBP) increase was 24 mm Hg in group I and 21 mm Hg in group II, and P(95) of upright DBP was 89 mm Hg in group I and 91 mm Hg in group II.

CONCLUSIONS

POTS is suggested when δ heart rate is ≥ 38 bpm (for easy memory, ≥ 40 bpm) from supine to upright, or maximum heart rate ≥ 130 bpm (children aged 6-12 years) and ≥ 125 pm (adolescents aged 13-18 years), associated with orthostatic symptoms. OHT is suggested when δ SBP (increase) is ≥ 20 mm Hg, and/or δ DBP (increase) ≥ 25 mm Hg (in children aged 6-12 years) or ≥ 20 mm Hg (in adolescents aged 13-18 years) from supine to upright; or upright BP ≥ 130/90 mm Hg (in children aged 6-12 years) or ≥ 140/90 mm Hg (in adolescents aged 13-18 years).

The C-1021T polymorphism of dopamine β-hydroxylase is not associated with orthostatic hypotension in a Chinese population

To explore the association between the dopamine β-hydroxylase (DBH) gene C-1021T polymorphism and the occurrence of orthostatic hypotension (OH) in Chinese patients, the DBH C-1021T polymorphism was genotyped in 317 patients with OH and 664 age- and sex-matched controls with orthostatic normotension. All subjects underwent an upright posture study for the measurement of orthostatic blood pressure. OH was defined as a drop in blood pressure of 20/10 mm Hg or more within 3 min of assuming the upright posture. The allele frequency of the DBH C-1021T polymorphism in the orthostatic hypotensive group was similar to the orthostatic normotensive group (17.4 versus 14.9%, P>0.05). No statistical significant association was found between the distribution of the C-1021T genotypes and the risk of OH in both the orthostatic hypotensive and orthostatic normotensive groups even after adjustment for demographic parameters. Among the three different genotypes, blood pressure levels did not significantly differ in the general population in this study. The changes in orthostatic systolic or diastolic blood pressures among the different genotype groups were not detected (all P>0.05). The C-1021T polymorphism of the DBH was not associated with orthostatic hypotensive risk in a Chinese population.

Pathophysiology of neurally-mediated syncope

INTRODUCTION

Neurally-mediated syncope (NMS) is defined as a transient loss of consciousness due to an abrupt and intermittent drop in blood pressure (BP).

OBJECTIVES

This study describes the putative pathophysiological mechanisms giving rise to NMS, the role of baroreflex (BR), and the interaction of its main haemodynamic variables: heart rate (HR) and BP.

DEVELOPMENT

Episodic dysregulation affects control over the haemodynamic variables (HR and BP) mediated by baroreflex mechanisms. During active standing, individuals experience a profound transient drop in systolic BP due to the effect of gravity on the column of blood and probably also because of reflex vasodilation. Abnormalities in the BR in NMS could be due to a more profound drop in BP upon standing, or to delayed or incomplete vasoconstriction resulting from inhibited or delayed sympathetic activity.

CONCLUSIONS

Sympathetic hyperactivity is present in patients with NMS at rest and before syncope. During active standing or passive tilting, excessive tachycardia may be followed by bradycardia and profound hypotension. Recovery of systolic BP is delayed or incomplete.

The association between within-visit blood pressure variability and carotid artery atherosclerosis in general population

Objectives

To determine whether within-visit blood pressure (BP) variability based on three measurements over minutes is associated with increased carotid intima-media thickness (IMT) and plaque in a general population.

Methods

A cross-sectional survey was performed in 2007, and a total of 1222 Beijing community residents aged 50–79 years belonging to part of the Chinese Multi-Provincial Cohort Study (CMCS) were recruited in this study. BP was measured three times at 5-minute intervals during a single visit, and the maximum absolute difference (MAD) between any two readings of three measurements was used to indicate within-visit BP variability. Carotid IMT and plaque scanned by B-mode ultrasound were identified as the surrogate end points in the intermediate stage of atherosclerosis.

Results

After adjustment for established cardiovascular risk factors, the odds ratio (OR) (95% confidence interval (CI)) for increased carotid IMT and internal carotid plaque associated with the highest within-visit diastolic BP (DBP) variability (MAD > mean + standard deviation (SD)) compared with participants in the lowest within-visit DBP variability (MAD ≤ mean −SD) was 4.92 (1.48–16.42) and 6.07 (1.31–28.10), respectively, in the normotensives (P = 0.01; P = 0.02). The OR (95% CI) for internal carotid plaque associated with the highest within-visit systolic BP (SBP) variability (MAD >mean +SD) compared with participants in the lowest within-visit SBP variability (MAD ≤ mean −SD) was 3.54 (1.26–10.00) in the hypertensives on antihypertensive therapy (P = 0.02).

Conclusions

Within-visit DBP variability was associated with increased carotid IMT and internal carotid plaque in the normotensive population, and within-visit SBP variability was associated with internal carotid plaque in hypertensive patients undergoing antihypertensive therapy.

Orthostatic hypotension in older adults with dementia

Orthostatic hypotension (OH) in older adults with dementia is associated with increased confusion, dizziness, syncope, and falls. These problems may result in a negative, downward spiral accompanied by high morbidity and mortality. The literature supports that nonpharmacological interventions are effective in the reduction of symptoms and prevention of orthostasis. The purpose of this quality improvement project was to increase staff knowledge and skill in the assessment, documentation, and care of residents with OH in dementia care units within a continuing care retirement community. An in-service program using a protocol based on clinical practice guidelines was presented to RNs, licensed practical nurses, therapists, and unlicensed caregivers. Assessments, documentation of assessments, and interventions for residents with OH increased following the in-service program. As staff continue to apply their knowledge in care routines, it is expected that this evidence-based practice will reduce symptoms of OH and increase safety and quality of life within this specific population.

Orthostatic hypertension-a new haemodynamic cardiovascular risk factor

Orthostatic hypertension-a condition characterized by a hyperactive pressor response to orthostatic stress-is an emerging risk factor for cardiovascular disease and is associated with hypertensive target-organ damage (resulting in silent cerebrovascular disease, left ventricular hypertrophy, carotid atherosclerosis and/or chronic kidney disease) and cardiovascular events (such as coronary artery disease and lacunar stroke). The condition is also considered to be a form of prehypertension as it precedes hypertension in young, normotensive adults. Orthostatic blood pressure changes can be assessed using orthostatic stress tests, including clinic active standing tests, home blood pressure monitoring and the head-up tilting test. Devices for home and for ambulatory blood pressure monitoring that are equipped with position sensors and do not induce a white-coat effect have increased the sensitivity and specificity of diagnosis of out-of-clinic orthostatic hypertension. Potential major mechanisms of orthostatic hypertension are sympathetic hyperactivity (as a result of hypersensitivity of the cardiopulmonary and arterial baroreceptor reflex) and α-adrenergic hyperactivation. Orthostatic hypertension is also associated with morning blood pressure surge and extreme nocturnal blood pressure dipping, both of which increase the pulsatile haemodynamic stress of central arterial pressure and blood flow in patients with systemic haemodynamic atherothrombotic syndrome.

Orthostatic hypertension: recognizing an underappreciated clinical condition

Orthostatic hypertension refers to an increase in the blood pressure upon assuming an upright posture. This clinical condition has been understudied and is often underappreciated in clinical practice probably because of its unfamiliarity to many clinicians including subspecialists. We report a case of severely symptomatic orthostatic hypertension in a Caucasian female, which was likely secondary to an autonomic dysfunction caused by an underlying vascular adrenergic hypersensitivity and possibly also due to uncontrolled diabetes mellitus (causing baroreflex dysfunction associated with excessive sympathetic stimulation). The case work-up also illustrates a schematic diagnostic and management approach to this rarely encountered clinical entity.

Exercise challenge in Gulf War Illness reveals two subgroups with altered brain structure and function

Nearly 30% of the approximately 700,000 military personnel who served in Operation Desert Storm (1990-1991) have developed Gulf War Illness, a condition that presents with symptoms such as cognitive impairment, autonomic dysfunction, debilitating fatigue and chronic widespread pain that implicate the central nervous system. A hallmark complaint of subjects with Gulf War Illness is post-exertional malaise; defined as an exacerbation of symptoms following physical and/or mental effort. To study the causal relationship between exercise, the brain, and changes in symptoms, 28 Gulf War veterans and 10 controls completed an fMRI scan before and after two exercise stress tests to investigate serial changes in pain, autonomic function, and working memory. Exercise induced two clinical Gulf War Illness subgroups. One subgroup presented with orthostatic tachycardia (n = 10). This phenotype correlated with brainstem atrophy, baseline working memory compensation in the cerebellar vermis, and subsequent loss of compensation after exercise. The other subgroup developed exercise induced hyperalgesia (n = 18) that was associated with cortical atrophy and baseline working memory compensation in the basal ganglia. Alterations in cognition, brain structure, and symptoms were absent in controls. Our novel findings may provide an understanding of the relationship between the brain and post-exertional malaise in Gulf War Illness.