Orthostatic hypertension: home blood pressure monitoring for detection and assessment of treatment with doxazosin

Assessment and management of exaggerated blood pressure response to standing and orthostatic hypertension: consensus statement by the European Society of Hypertension Working Group on Blood Pressure Monitoring and Cardiovascular Variability

Recent evidence suggests that an exaggerated blood pressure (BP) response to standing (ERTS) is associated with an increased risk of adverse outcomes, both in young and old individuals. In addition, ERTS has been shown to be an independent predictor of masked hypertension. In the vast majority of studies reporting on the prognostic value of orthostatic hypertension (OHT), the definition was based only on systolic office BP measurements. This consensus statement provides recommendations on the assessment and management of individuals with ERTS and/or OHT. ERTS is defined as an orthostatic increase in SBP at least 20 mmHg and OHT as an ERTS with standing SBP at least 140 mmHg. This statement recommends a standardized methodology to assess ERTS, by considering body and arm position, and the number and timing of BP measurements. ERTS/OHT should be confirmed in a second visit, to account for its limited reproducibility. The second assessment should evaluate BP changes from the supine to the standing posture. Ambulatory BP monitoring is recommended in most individuals with ERTS/OHT, especially if they have high-normal seated office BP. Implementation of lifestyle changes and close follow-up are recommended in individuals with ERTS/OHT and normotensive seated office BP. Whether antihypertensive treatment should be administered in the latter is unknown. Hypertensive patients with ERTS/OHT should be managed as any other hypertensive patient. Standardized standing BP measurement should be implemented in future epidemiological and interventional studies.

Cardiopulmonary deconditioning and plasma volume loss are not sufficient to provoke orthostatic hypertension

Orthostatic hypertension, defined by an increase of systolic blood pressure (SBP) of ≥20 mmHg upon standing, harbors an increased cardiovascular risk. We pooled data from two rigorously conducted head-down tilt bedrest studies to test the hypothesis that cardiopulmonary deconditioning and hypovolemia predispose to orthostatic hypertension. With bedrest, peak VO2 decreased by 6 ± 4 mlO2/min/kg (p < 0.0001) and plasma volume by 367 ± 348 ml (p < 0.0001). Supine SBP increased from 127 ± 9 mmHg before to 133 ± 10 mmHg after bedrest (p < 0.0001). In participants with stable hemodynamics following head-up tilt, the incidence of orthostatic hypertension was 2 out of 67 participants before bedrest and 2 out of 57 after bedrest. We conclude that in most healthy persons, cardiovascular deconditioning and volume loss associated with long-term bedrest are not sufficient to cause orthostatic hypertension.

Orthostatic Hypertension: A Newcomer Among the Hypertension Phenotypes

The prognostic role and the clinical significance of orthostatic hypertension (OHT) remained undefined for long because data were sparse and often inconsistent. In recent years, evidence has been accumulating that OHT is associated with an increased risk of masked and sustained hypertension, hypertension-mediated organ damage, cardiovascular disease, and mortality. Most evidence came from studies in which OHT was defined using systolic blood pressure (BP) whereas the clinical relevance of diastolic OHT is still unclear. Recently, the American Autonomic Society and the Japanese Society of Hypertension defined OHT as an orthostatic systolic BP increase ≥20 mm Hg associated with a systolic BP of at least 140 mm Hg while standing. However, also smaller orthostatic BP increases have shown clinical relevance especially in people ≤45 years of age. A possible limitation of the BP response to standing is poor reproducibility. OHT concordance is better when the between-assessment interval is shorter, when OHT is evaluated using a larger number of BP readings, and if home BP measurement is used. The pathogenetic mechanisms leading to OHT are still controversial and may vary according to age. Excessive neurohumoral activation seems to be the main determinant in younger adults whereas vascular stiffness plays a more important role in older individuals. Conditions associated with higher activity of the sympathetic nervous system and/or baroreflex dysregulation, such as diabetes, essential hypertension, and aging have been found to be often associated with OHT. Measurement of orthostatic BP should be included in routine clinical practice especially in people with high-normal BP.

Consensus statement on the definition of orthostatic hypertension endorsed by the American Autonomic Society and the Japanese Society of Hypertension

We propose a consensus definition of "an exaggerated orthostatic pressor response" in subjects in whom systolic blood pressure increases ≥ 20 mmHg when going from supine to standing posture. This definition can be extended for seated to standing measurements. We reserve the term "orthostatic hypertension" for when this pressor response leads to an upright systolic blood pressure ≥ 140 mmHg. We believe this consensus definition will help in the study of the pathophysiology, clinical impact, and potential treatment of these entities, and identification of patients who are at greater cardiovascular risk.

Consensus statement on the definition of orthostatic hypertension endorsed by the American Autonomic Society and the Japanese Society of Hypertension

We propose a consensus definition of "an exaggerated orthostatic pressor response" in subjects in whom systolic blood pressure increases ≥20 mmHg when going from the supine to standing posture. This definition can be extended for seated to standing measurements. We reserve the term "orthostatic hypertension" if this pressor response leads to an upright systolic blood pressure ≥140 mmHg. We believe this consensus definition will help in the study of the pathophysiology, clinical impact, and potential treatment of these entities, and the identification of patients that are at greater cardiovascular risk.

Blood pressure response to standing is a strong determinant of masked hypertension in young to middle-age individuals

OBJECTIVE

The pathophysiologic mechanisms of masked hypertension are still debated. The aim of this study was to investigate whether the blood pressure response to standing is a determinant of masked hypertension in young individuals.

DESIGN AND METHODS

We studied 1078 individuals (mean age 33.2 ± 8.5 years) with stage-1 untreated hypertension at baseline. Orthostatic response was defined as the difference between six SBP measurements in the orthostatic and supine postures. People with a response more than 6.5 mmHg (upper decile) were defined as hyperreactors. After 3 months of follow-up, 24-h ambulatory BP was measured and the participants were classified as normotensives (N = 120), white-coat hypertensive individuals (N = 168), masked hypertensive individuals (N = 166) and sustained hypertensive individuals (N = 624). In 591 participants, 24-h urinary epinephrine was also measured.

RESULTS

Orthostatic response was an independent predictor of masked hypertension after 3 months (P = 0.001). In the whole group, the odds ratio for the Hyperreactors was 2.5 [95% confidence interval (95% CI) 1.5-4.0, P < 0.001]. In the participants stratified by orthostatic response and urinary epinephrine, the odds ratio for masked hypertension was 4.2 (95% CI, 1.8-9.9, P = 0.001) in the hyperreactors with epinephrine above the median and was 2.6 (95% CI, 0.9-7.3, P = 0.069) in those with epinephrine below the median. The association between orthostatic response and masked hypertension was confirmed in the cross-sectional analysis after 3 months (P < 0.001).

CONCLUSION

The present findings indicate that hyperreactivity to standing is a significant determinant of masked hypertension. The odds ratio for masked hypertension was even quadrupled in people with an orthostatic response more than 6.5 mmHg and high urinary epinephrine suggesting a role of sympathoadrenergic activity in the pathogenesis of masked hypertension.

Role of α1-blockers in the current management of hypertension

There is emerging evidence that α1-blockers can be safely used in the treatment of hypertension. These drugs can be used in almost all hypertensive patients for blood pressure control. However, there are several special indications. Benign prostatic hyperplasia is a compelling indication of α1-blockers, because of the dual treatment effect on both high blood pressure and lower urinary tract symptoms. Many patients with resistant hypertension would require α1-blockers as add-on therapy. Primary aldosteronism screen is a rapidly increasing clinical demand in the management of hypertension, where α1-blockers are useful for blood pressure control in the preparation for the measurement of plasma aldosterone and renin. Nonetheless, α1-blockers have to be used under several considerations. Among the currently available agents, only long-acting α1-blockers, such as doxazosin gastrointestinal therapeutic system 4-8 mg daily and terazosin 2-4 mg daily, should be chosen. Orthostatic hypotension is a concern with the use of α1-blockers especially in the elderly, and requires careful initial bedtime dosing and avoiding overdosing. Fluid retention is potentially also a concern, which may be overcome by combining an α1-blocker with a diuretic.

Blood Pressure Hyperreactivity to Standing: a Predictor of Adverse Outcome in Young Hypertensive Patients

The prognostic significance and the mechanisms of blood pressure (BP) hyperreactivity to standing remain controversial. This study aims to evaluate the association of orthostatic hyperreactivity with major adverse cardiovascular and renal events in a cohort of young hypertensive subjects. We studied 1207 untreated subjects screened for stage I hypertension with a mean age of 33.1±8.6 years. The orthostatic BP change was calculated as the difference between 6 standing and 6 supine BP readings obtained during 2 separate visits. Hyperreactivity to standing was defined as the standing-supine systolic BP difference in the top decile. The mean difference in the whole group was -2.5±7.3/4.6±5.4 mm Hg. Ambulatory hypertension evaluated with 24-hour recordings was more common in Hyperreactors than Normoreactors (90.8% versus 76.4%, P=0.001). In 630 participants in whom 24-hour urinary catecholamines were measured, epinephrine/creatinine ratio was higher in hyperreactors (118.4±185.6 versus 77.0±90.1 nmol/mol, P=0.005). During a 17.2-year follow-up, 105 major adverse cardiovascular and renal events were accrued. In a multivariate Cox model, hyperreactivity to standing was an independent predictor of major adverse cardiovascular and renal events with a hazard ratio of 1.97 (95% CI, 1.10-3.52). Hyperreactivity remained an independent predictor of adverse events even when ambulatory BP data and incident hypertension during follow-up were included in the Cox model (hazard ratio, 1.94 [95% CI, 1.10-3.44]). Our data indicate that in young-to-middle-age hypertensive subjects an exaggerated systolic BP response to standing is associated with sympatho-adrenergic hyperreactivity and is an independent predictor of major adverse cardiovascular and renal events. Orthostatic BP assessment gives the advantage of simple acquisition and provides prognostic information on top of ambulatory BP.

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.

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.

Sitting-induced hemodynamic changes and association with sitting intolerance in children and adolescents: a cross-sectional study

Hemodynamic alteration with postural change from supine to sitting has been unclear in the young. In the cross-sectional study, 686 participants (371 boys and 315 girls, aged 6-18 years) were recruited from 4 schools in Kaifeng city, the central area of China. The active sitting test was performed to obtain heart rate (HR) and blood pressure (BP) changes from supine to sitting in children and adolescents. Hemodynamic change-associated sitting intolerance was analyzed. In the study participants, the 95th percentile (P95) values of changes in HR and BP within 3 min from supine to sitting were 25 beats/min and 18/19 mm Hg, respectively. Sixty-six participants had sitting intolerance symptoms. Compared with participants without sitting intolerance symptoms, those with symptoms more frequently had HR increase ≥ P95 or BP increase ≥ P95 within 3 min from supine to sitting (P < 0.001). Risk factors for sitting intolerance were age (odds ratio 1.218, 95% confidence interval 1.072-1.384, P = 0.002) and changes in HR or BP ≥ P95 within 3 min after sitting (odds ratio 2.902, 95% confidence interval 1.572-5.357, P = 0.001). We firstly showed hemodynamic changing profiles from supine to sitting and their association with sitting intolerance in children and adolescents. Sitting tachycardia is likely suggested with a change in HR ≥ 25 beats/min and sitting hypertension with a change in BP ≥ 20/20 mm Hg when changing from supine to sitting within 3 min. The age and changes in HR or BP were independent risk factors for sitting intolerance.

Orthostatic Hypertension in Children: An Update

The concept of orthostatic hypertension in children was first proposed in 2012. The pathogenesis is not clear by now. Orthostatic hypertension is one of the important causes of orthostatic intolerance in children and is related to the development of essential hypertension in the future. It is commonly seen in older children, with dizziness and syncope as their main clinical manifestations. Non-drug therapy is the commonly used treatment strategy, which is effective to improve the orthostatic intolerance symptoms. In this paper, we reviewed the clinical studies on the pathogenesis, clinical characteristics, diagnostic criteria, and treatment of orthostatic hypertension in children, aiming to provide new insights for the future studies on pediatric orthostatic hypertension.

Orthostatic Hypertension: Critical Appraisal of an Overlooked Condition

Orthostatic hypertension, which appears to be mediated through excess neurohumoral activation while standing, is a common blood pressure trait among patients with and without arterial hypertension. However, lack of consensus regarding the definition of orthostatic hypertension makes it difficult to assess the true prevalence of this condition. Orthostatic hypertension appears to predict the risk for progression to arterial hypertension in younger and risk of cardiovascular morbidity and mortality in older persons. Yet, the risk may differ between populations. Whether orthostatic hypertension indicates a generally increased risk of death, constitutes an intermediate variable in the causal pathway of cardiovascular risk factors, a simple measure of disease severity, or an independently acting mechanism is not known. Since both orthostatic hypotension and orthostatic hypertension herald increased risk of cardiovascular disease, it appears reasonable to screen the patients for abnormal orthostatic blood pressure responses using simple orthostatic testing. However, how presence of orthostatic hypertension may affect clinical management decisions such as the choice of antihypertensive drugs is currently difficult to ascertain. Clearly, this issue deserves more attention.

Sympathetic Overactivation From Supine to Upright Is Associated With Orthostatic Hypertension in Children and Adolescents

There are no prior publications or submissions with any overlapping information, including studies and patients. The study data have not been presented as an abstract or poster before the submission. Objectives: The study was conducted to analyze the changes of baroreflex sensitivity and heart rate variability from supine to upright standing in children and adolescents with orthostatic hypertension to explore whether and how the autonomic nerve regulation was involved in the development of pediatric orthostatic hypertension. Methods: This case-control study included twenty-five children with orthostatic hypertension (the patient group) and twenty-six healthy controls (the control group). All subjects underwent a standing test, during which their hemodynamic parameters were continuously monitored by a Finapres Medical System, and baroreflex sensitivity and heart rate variability were calculated. Results: The demographic characteristics, supine baroreflex sensitivity, and supine heart rate variability including time domain and frequency domain indices did not differ between the patients with orthostatic hypertension and healthy subjects (P > 0.05). However, a more obvious drop of baroreflex sensitivity and a greater increase of low frequency/high frequency ratio from supine to upright were observed in subjects with orthostatic hypertension compared with those in the healthy children (P < 0.001 and P < 0.01, respectively). Changes of baroreflex sensitivity were negatively related to mean arterial pressure changes from supine to upright in all subjects (P < 0.01), and the increases in low frequency/high frequency ratio from supine to standing were positively correlated with those in mean arterial pressure in the study subjects (P < 0.001). Conclusion: Upright sympathetic overactivation is associated with pediatric orthostatic hypertension.

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.

Orthostatic hypotension and orthostatic hypertension in American veterans

PURPOSE

Abnormal blood pressure (BP) response to orthostatic maneuvers may predict adverse health outcomes. Orthostatic hypotension (OH) is defined as a fall in BP of ≥20/10 mmHg, and orthostatic hypertension (OHTN) is defined as an increase in systolic BP (SBP) of ≥20 mmHg, with standing. Herein, we document the prevalence of OH and OHTN in American veterans.

METHODS

The influence of demographic characteristics, life habits, co-incident medical conditions, and prescription medication use on these prevalence rates and associations between abnormal orthostatic BP responses and severity of self-reported symptoms of fatigue, dizziness, trouble concentrating, and head and neck discomfort were determined.

RESULTS

286 veterans participated; 14 % were classified with OH, 22 % with OHTN, and 64 % with normal BP responses to standing (reference group). An increased prevalence of the diagnosis of diabetes mellitus (27 %) and hypertension (63 %) was noted, which did not differ by orthostatic BP classification. Veterans with OH were older than the reference group and were prescribed more antihypertensive medications than the reference and OHTN groups. While the prevalence of OH increased with age, the prevalence of OHTN was comparable in young (20-30 years) and old (70+ years) veterans (17 vs. 19 %, respectively). The severity of fatigue and dizziness was increased in veterans with OH and OHTN compared to the reference group.

CONCLUSION

These data suggest a relatively high prevalence of OH and OHTN, which is associated with increased self-reported severity of fatigue and dizziness in American veterans, findings which may adversely impact long-term health outcomes.

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.