Water drinking improves orthostatic tolerance in patients with posturally related syncope

2006 ◽  
Vol 110 (3) ◽  
pp. 343-352 ◽  
Author(s):  
Victoria E. Claydon ◽  
Christoph Schroeder ◽  
Lucy J. Norcliffe ◽  
Jens Jordan ◽  
Roger Hainsworth
Keyword(s):  
Blood Pressure ◽  
Cerebral Blood Flow Velocity ◽  
Peripheral Resistance ◽  
Orthostatic Tolerance ◽  
Lower Body ◽  
Water Drinking ◽  
Randomized Controlled ◽  
Combined Test ◽  
Time Required ◽  
The Relationship

Water drinking improves OT (orthostatic tolerance) in healthy volunteers; however, responses to water in patients with PRS (posturally related syncope) are unknown. Therefore the aim of the present study was to examine whether water would improve OT in patients with PRS. In a randomized controlled cross-over fashion, nine patients with PRS ingested 500 ml and 50 ml (control) of water 15 min before tilting on two separate days. OT was determined using a combined test of head-up tilting and lower body suction and expressed as the time required to induce presyncope. We measured blood pressure and heart rate (using Portapres®) and middle cerebral artery velocity (using transcranial Doppler). SV (stroke volume) and TPR (total peripheral resistance) were calculated using the Modelflow® method. OT was significantly (P<0.02) greater after drinking 500 ml of water than after 50 ml (25.4±1.5 compared with 19.8±2.3 min respectively). After ingestion of 500 ml of water, blood pressure during tilting was higher, the tiltinduced reduction in SV was smaller and the increase in TPR was greater (all P<0.05). The correlation coefficient of the relationship between cerebral blood flow velocity and pressure was lower after 500 ml of water (0.43±0.1 compared with 0.73±0.1; P<0.05), indicating better autoregulation. In conclusion, drinking 500 ml of water increased OT and improved cardiovascular and cerebrovascular control during orthostasis. Patients with PRS should be encouraged to drink water before situations likely to precipitate a syncopal attack.

Hemodynamic Strategies in Blood Pressure Regulation During Orthostatic Challenge in Women

1997 ◽  
Vol 22 (4) ◽  
pp. 351-367
Author(s):  
Tania L. Culham ◽  
Gabrielle K. Savard
Keyword(s):  
Blood Pressure ◽  
Arterial Pressure ◽  
Stroke Volume ◽  
Negative Pressure ◽  
Lower Body Negative Pressure ◽  
Peripheral Resistance ◽  
Orthostatic Tolerance ◽  
Lower Body ◽  
Orthostatic Challenge ◽  
Carotid Baroreflex

Several studies indicate that carotid baroreflex responsiveness is a good predictor of orthostatic tolerance. Two groups of healthy women with high (HI) and low (LO) carotid baroreflex responsiveness were studied (a) to determine any differences in the level of orthostatic tolerance of the two groups, and (b) to study the hemodynamic strategies used by HI and LO responders to regulate arterial pressure during the orthostatic challenge of lower body negative pressure (LBNP). Orthostatic tolerance was similar between the two groups, whereas the hemodynamic strategies recruited to maintain blood pressure at −40 mmHg LBNP differed: HI responders exhibited greater LBNP-induced decreases in stroke volume and cardiac output, as well as a greater increase in peripheral resistance compared to LO responders (p < .05). In addition, a significant increase in plasma renin activity during LBNP was found in the HI responders only. No significant between-group differences were found in arterial and cardiopulmonary control of vascular resistance or arterial haroreflex control of heart rate during LBNP. Key words: arterial pressure, carotid baroreceptor, lower body negative pressure, orthostatic tolerance, stroke volume

scholarly journals Water Drinking Induces Thermogenesis through Osmosensitive Mechanisms

2007 ◽  
Vol 92 (8) ◽  
pp. 3334-3337 ◽  
Author(s):  
Michael Boschmann ◽  
Jochen Steiniger ◽  
Gabriele Franke ◽  
Andreas L. Birkenfeld ◽  
Friedrich C. Luft ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Healthy Subjects ◽  
Crossover Trial ◽  
Normal Weight ◽  
Gastric Distension ◽  
Men And Women ◽  
Water Drinking ◽  
Randomized Controlled ◽  
Response To Water ◽  
Thermogenic Response

Abstract Context: Recently, we showed that drinking 500 ml water induces thermogenesis in normal-weight men and women. Objective: We now repeated these studies in a randomized, controlled, crossover trial in overweight or obese otherwise healthy subjects (eight men and eight women), comparing also the effects of 500 ml isoosmotic saline or 50 ml water. Results: Only 500 ml water increased energy expenditure by 24% over the course of 60 min after ingestion, whereas isoosmotic saline and 50 ml water had no effect. Heart rate and blood pressure did not change in these young, healthy subjects. Conclusions: Our data exclude volume-related effects or gastric distension as the mediator of the thermogenic response to water drinking. Instead, we hypothesize the existence of a portal osmoreceptor, most likely an ion channel.

ACE I/D Genotype, Habitual Physical Activity, and Blood Pressure in Children

2010 ◽  
Vol 22 (2) ◽  
pp. 301-313 ◽  
Author(s):  
Mark A. Sarzynski ◽  
Joey C. Eisenmann ◽  
Gregory J. Welk ◽  
Jared Tucker ◽  
Kim Glenn ◽  
...  
Keyword(s):  
Physical Activity ◽  
Blood Pressure ◽  
Vigorous Physical Activity ◽  
Lower Body ◽  
Converting Enzyme ◽  
Resting Blood Pressure ◽  
Female Children ◽  
Partial Correlations ◽  
Ace Genotype ◽  
The Relationship

The present study examined the association between the angiotensin converting enzyme (ACE) insertion/deletion (I/D) polymorphism, physical activity, and resting blood pressure (BP) in a sample of 132 children (48.4% female). Children attaining 60 min/day of moderate-to-vigorous physical activity (MVPA) possessed lower % body fat (29% vs 24%, p < .05). Resting BP did not significantly differ between genotypes. Furthermore, partial correlations between MVPA and BP were low and did not vary by ACE genotype. Thus, the ACE I/D genotype is not associated with BP and does not modify the relationship between physical activity and BP in this sample of children.

Effect of Two Bathing Methods on Physiologic Parameters in Pediatric Intensive Care

2021 ◽  
pp. 105477382110433
Author(s):  
Özgül Öz ◽  
Gülzade Uysal ◽  
Duygu Sönmez Düzkaya
Keyword(s):  
Blood Pressure ◽  
Intensive Care Unit ◽  
Randomized Controlled Trial ◽  
Intensive Care ◽  
Controlled Trial ◽  
Pediatric Intensive Care ◽  
Lower Body ◽  
Randomized Controlled ◽  
Physiologic Parameters ◽  
Positive Effect

To determine the effect of traditional and disposable bed baths performed in the pediatric intensive care unit (PICU) on the physiologic parameters of children. This research was conducted as a randomized controlled trial with children who were monitored in the PICU. It was found that the pulse and blood pressure immediately after the bath were higher for both bath applications and was the lowest 30 minutes after the bath ( p < .05). Children who used traditional baths had a lower body temperature than those who used the disposable bed bath after bathing for the second day. Oxygen saturation averages were found that within the group to be the highest 30 minutes after bathing methods ( p < .05). Both bathing methods applied in the PICU had a positive effect on physiologic parameters. It may be recommended to regularly perform the most appropriate bathing for patients with stable hemodynamics in PICUs.

scholarly journals Validity of auscultatory and Penaz blood pressure measurements during profound heat stress alone and with an orthostatic challenge

2011 ◽  
Vol 301 (5) ◽  
pp. R1510-R1516 ◽  
Author(s):  
Matthew S. Ganio ◽  
R. Matthew Brothers ◽  
Rebekah A. I. Lucas ◽  
Jeffrey L. Hastings ◽  
Craig G. Crandall
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Heat Stress ◽  
Brachial Artery ◽  
Lower Body Negative Pressure ◽  
Peripheral Resistance ◽  
Pressure Measurements ◽  
Lower Body ◽  
Dynamic Changes ◽  
Orthostatic Challenge

Despite frequent reporting of blood pressure (BP) during profound passive heat stress, both with and without a hypotensive challenge, the method by which BP is measured often varies between laboratories. It is unknown whether auscultatory and finger BP measures accurately reflect intra-arterial BP during dynamic changes in cardiac output and peripheral resistance associated with the aforementioned conditions. The purpose of this investigation was to test the hypothesis that auscultatory BP measured at the brachial artery, and finger BP measured by the Penaz method, are valid measures of intra-arterial BP during a passive heat stress and a heat-stressed orthostatic challenge, via lower body negative pressure (LBNP). Absolute (specific aim 1) and the change in (specific aim 2) systolic (SBP), diastolic (DBP), and mean BPs (MBP) were compared at normothermia, after a core temperature increase of 1.47 ± 0.09°C, and during subsequent LBNP. Heat stress did not change auscultatory SBP (6 ± 11 mmHg; P = 0.16), but Penaz SBP (−22 ± 16 mmHg; P < 0.001) and intra-arterial SBP (−11 ± 13 mmHg P = 0.017) decreased. In contrast, DBP and MBP did not differ between methods throughout heat stress. Compared with BP before LBNP, the magnitude of the reduction in BP with all three methods was similar throughout LBNP ( P > 0.05). In conclusion, auscultatory SBP and Penaz SBP failed to track the decrease in intra-arterial SBP that occurred during the profound heat stress, while decreases in arterial BP during an orthostatic challenge are comparable between methodologies.

Effects of gender and hypovolemia on sympathetic neural responses to orthostatic stress

2005 ◽  
Vol 289 (1) ◽  
pp. R109-R116 ◽  
Author(s):  
Qi Fu ◽  
Sarah Witkowski ◽  
Kazunobu Okazaki ◽  
Benjamin D. Levine
Keyword(s):  
Blood Pressure ◽  
Stroke Volume ◽  
Lower Body Negative Pressure ◽  
Muscle Sympathetic Nerve Activity ◽  
Peripheral Resistance ◽  
Orthostatic Stress ◽  
Stroke Index ◽  
Orthostatic Tolerance ◽  
Neural Responses ◽  
Men And Women

We tested the hypothesis that women have blunted sympathetic neural responses to orthostatic stress compared with men, which may be elicited under hypovolemic conditions. Muscle sympathetic nerve activity (MSNA) and hemodynamics were measured in eight healthy young women and seven men in supine position and during 6 min of 60° head-up tilt (HUT) under normovolemic and hypovolemic conditions (randomly), with ∼4-wk interval. Acute hypovolemia was produced by diuretic (furosemide) administration ∼2 h before testing. Orthostatic tolerance was determined by progressive lower body negative pressure to presyncope. We found that furosemide produced an ∼13% reduction in plasma volume, causing a similar increase in supine MSNA in men and women (mean ± SD of 5 ± 7 vs. 6 ± 5 bursts/min; P = 0.895). MSNA increased during HUT and was greater in the hypovolemic than in the normovolemic condition (32 ± 6 bursts/min in normovolemia vs. 44 ± 15 bursts/min in hypovolemia in men, P = 0.055; 35 ± 9 vs. 45 ± 8 bursts/min in women, P < 0.001); these responses were not different between the genders (gender effect: P = 0.832 and 0.814 in normovolemia and hypovolemia, respectively). Total peripheral resistance increased proportionately with increases in MSNA during HUT; these responses were similar between the genders. However, systolic blood pressure was lower, whereas diastolic blood pressure was similar in women compared with men during HUT, which was associated with a smaller stroke volume or stroke index. Orthostatic tolerance was lower in women, especially under hypovolemic conditions. These results indicate that men and women have comparable sympathetic neural responses during orthostatic stress under normovolemic and hypovolemic conditions. The lower orthostatic tolerance in women is predominantly because of a smaller stroke volume, presumably due to less cardiac filling during orthostasis, especially under hypovolemic conditions, which may overwhelm the vasomotor reserve available for vasoconstriction or precipitate neurally mediated sympathetic withdrawal and syncope.

scholarly journals Cuff-Method Thigh Arterial Occlusion Counteracts Cerebral Hypoperfusion Against the Push–Pull Effect in Humans

2021 ◽  
Vol 12 ◽  
Author(s):  
Changyang Xing ◽  
Yuan Gao ◽  
Xinpei Wang ◽  
Wenjuan Xing ◽  
Yunnan Liu ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
High Performance ◽  
Cerebral Blood Flow Velocity ◽  
Blood Pressure Response ◽  
Peripheral Resistance ◽  
Arterial Occlusion ◽  
Resistance Index ◽  
Systemic Blood Pressure ◽  
Cerebral Hypoperfusion

Exposure to acute transition from negative (−Gz) to positive (+ Gz) gravity significantly impairs cerebral perfusion in pilots of high-performance aircraft during push—pull maneuver. This push—pull effect may raise the risk for loss of vision or consciousness. The aim of the present study was to explore effective countermeasures against cerebral hypoperfusion induced by the push—pull effect. Twenty healthy young volunteers (male, 21 ± 1 year old) were tested during the simulated push–pull maneuver by tilting. A thigh cuff (TC) pressure of 200 mmHg was applied before and during simulated push—pull maneuver (−0.87 to + 1.00 Gz). Beat-to-beat cerebral and systemic hemodynamics were measured continuously. During rapid −Gz to + Gz transition, mean cerebral blood flow velocity (CBFV) was decreased, but to a lesser extent, in the TC bout compared with the control bout (−3.1 ± 4.9 vs. −7.8 ± 4.4 cm/s, P &lt; 0.001). Similarly, brain-level mean blood pressure showed smaller reduction in the TC bout than in the control bout (−46 ± 12 vs. −61 ± 13 mmHg, P &lt; 0.001). The systolic CBFV was lower but diastolic CBFV was higher in the TC bout. The systemic blood pressure response was blunted in the TC bout, along with similar heart rate increase, smaller decrease, and earlier recovery of total peripheral resistance index than control during the gravitational transition. These data demonstrated that restricting thigh blood flow can effectively mitigate the transient cerebral hypoperfusion induced by rapid shift from −Gz to + Gz, characterized by remarkable improvement of cerebral diastolic flow.

Abstract P469: Association Between Quality and Patterns of Sleep and Ideal Cardiovascular Health in Black Americans: Results From the Morehouse-Emory Cardiovascular (MECA) Center for Health Equity

Circulation ◽  
2020 ◽  
Vol 141 (Suppl_1) ◽  
Author(s):  
Shabatun Islam ◽  
Jeong Hwan Kim ◽  
Syed Ahmad ◽  
Matthew L Topel ◽  
Peter Baltrus ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Sleep Quality ◽  
Cardiovascular Health ◽  
Multinomial Logistic Regression ◽  
Black Americans ◽  
Group Differences ◽  
Poor Sleep ◽  
Ideal Cardiovascular Health ◽  
Time Required ◽  
The Relationship

Introduction: Sleep is hypothesized to be a contributing factor towards disparities in cardiovascular disease (CVD). It has been demonstrated that Black Americans have worse sleep quality compared to other ethnic groups, but within group differences have not been studied. Whether overall sleep quality and patterns affect cardiovascular health (CVH) among Blacks has yet to be elucidated. Hypothesis: Black individuals reporting worse sleep quality and patterns will have poor CVH as measured by the American Heart Association’s Life’s Simple 7 (LS7) scores. Methods: We recruited 499 Black adults (age 53 ± 10, 38% male) without known CVD from the Atlanta, GA metropolitan area. Sleep quality and patterns were assessed by the Pittsburgh Sleep Quality Index (PSQI) which includes sleep quality, nighttime disturbance, efficiency (amount of time slept while in bed), daytime dysfunction, duration, need of medications and latency (time required to fall asleep). CVH was determined by LS7 scores calculated from measured blood pressure, glucose, cholesterol, body mass index (BMI), and self-reported exercise, diet, and smoking, and categorized into poor (0-8), intermediate (9-10), and ideal (11-14). Multinomial logistic regression was used to examine the relationship between sleep and the odds of intermediate (vs. poor) and ideal (vs. poor) CVH categories after adjusting for age, gender, household income, education, marital status, and employment status. Results: A total of 55 (11%), 107 (21%), and 337 (67%) participants had ideal, intermediate, and poor LS7 scores, respectively. Those reporting PSQI-assessed poor sleep quality (OR 0.50, 95% CI [0.33 - 0.78]), longer latency (OR 0.50, 95% CI [0.36 - 0.70]), disturbance (OR 0.45, 95% CI [0.26 - 0.77]) and daytime dysfunction (OR 0.52, 95% CI [0.31 - 0.89]) had significantly lower adjusted odds of having ideal CVH. Daytime dysfunction was significantly associated with lower adjusted odds of having ideal blood pressure (OR 0.57, 95% CI [0.38 - 0.87]), glucose (OR 0.71, 95% CI [0.51 - 0.98]), and physical activity (OR 0.58, 95% CI [0.36 - 0.93]). Similarly, longer latency was significantly associated with lower adjusted odds of having ideal BMI (OR 0.72, 95% CI [0.54 - 0.95]), blood pressure (OR 0.71, 95% CI [0.55 - 0.92]), and cholesterol (OR 0.73, 95% CI [0.55 - 0.98]). PSQI-assessed shorter sleep duration was not associated with poor overall CVH, but was associated with significantly lower adjusted odds of having ideal blood pressure (OR 0.77, 95% CI [0.61 - 0.99]). Conclusion: Among Black Americans, poor sleep in terms of quality, nighttime disturbance, daytime dysfunction and longer latency, was associated with worse overall CVH or its components. Whether addressing sleep quality in Blacks will improve CVH and outcomes needs to be studied.

Orthostatic intolerance during a 13-day bed rest does not result from increased leg compliance

1993 ◽  
Vol 74 (1) ◽  
pp. 286-292 ◽  
Author(s):  
F. M. Melchior ◽  
S. M. Fortney
Keyword(s):  
Orthostatic Intolerance ◽  
Lower Body Negative Pressure ◽  
Bed Rest ◽  
Venous Occlusion ◽  
Orthostatic Tolerance ◽  
Lower Body ◽  
Pressure Test ◽  
Before And After ◽  
Negative Pressure Test ◽  
The Relationship

Increased leg compliance (LC) has been proposed as a mechanism for orthostatic intolerance after spaceflight or bed rest. Using venous occlusion plethysmography with mercury-in-Silastic strain gauge, we evaluated LC before, during, and after a 13-day head-down (-6 degrees) bed rest in 10 men. LC was measured by the relationship between the increased calf areas (in cm2) at thigh cuff occlusions of 20, 30, 50, 70, and 80 mmHg. Orthostatic tolerance was evaluated by a presyncopal-limited lower body negative pressure test (PSL-LBNP) before and after bed rest. The 10 subjects were divided into TOL (n = 5) and INT (n = 5) groups for which the orthostatic tolerance was similar and lower after bed rest, respectively. For TOL (INT) before bed rest, calf area increases were 2.2 +/- 0.5 (SE) (1.3 +/- 0.4), 3.5 +/- 0.7 (2.3 +/- 0.5), 5.0 +/- 0.9 (3.5 +/- 0.6), 5.6 +/- 0.9 (4.4 +/- 0.6), and 6.4 +/- 1.1 (4.7 +/- 0.6) cm2 for thigh occlusion pressures of 20, 30, 50, 70, and 80 mmHg, respectively. Neither for INT nor for TOL were these results significantly changed by bed rest. These results suggest that other mechanisms than increased LC have to be taken into account to explain the decreased orthostatic tolerance induced by this 13-day bed rest.

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