scholarly journals The effects of extracellular volume and intradialytic peripheral resistance changes on ambulatory blood pressure in hemodialysis patients with and without recurrent intradialytic hypertension

2020 ◽  
Author(s):  
Meredith McAdams ◽  
L Parker Gregg ◽  
Rong Lu ◽  
Michael Concepcion ◽  
Swati Lederer ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Ambulatory Blood Pressure ◽  
Total Peripheral Resistance ◽  
Extracellular Volume ◽  
Peripheral Resistance ◽  
Resistance Index ◽  
Interdialytic Weight Gain ◽  
Weight Gain Percentage ◽  
Total Peripheral Resistance Index

Abstract Background Hypertension and extracellular volume (ECV) overload are interrelated mortality risk factors in hemodialysis (HD) patients, but confounding related to changes in ECV and vasoconstriction during and between treatments obfuscate their relationship. We sought to clarify independent contributions of post-HD ECV and intradialytic changes in vasoconstriction on ambulatory blood pressure (BP) in patients with and without recurrent intradialytic hypertension (IH). Methods In this prospective observational study, we obtained measurements of pre- and post-HD ECV with bioimpedance spectroscopy (BIS), pre- and post-HD total peripheral resistance index and 44-h ambulatory BP. Linear regression determined associations between post-HD ECV/weight and intradialytic change in total peripheral resistance index (TPRI) with interdialytic BP and slope. Results In fully-adjusted models for participants with complete data, post-HD ECV/weight associated with mean ambulatory BP (β = 133, P = 0.01; n = 52) and ambulatory BP slope (β = −4.28, P = 0.03; n = 42). ECV/weight was associated with mean ambulatory BP in those with recurrent IH (β = 314, P = 0.0005; n = 16) and with ambulatory BP slope in those without recurrent IH (β = −4.56, P = 0.04; n = 28). Interdialytic weight gain percentage and intradialytic TPRI change were not associated with ambulatory BP or slope in any analyses. Conclusion Ambulatory BP in HD patients is more strongly associated with post-HD ECV assessed with BIS than with intradialytic TPRI changes or interdialytic ECV increases. These findings highlight the essential role of recognizing and managing chronic ECV overload to improve ambulatory BP in HD patients, particularly so for those with IH.

Hemodynamic monitoring for 24 h in unanesthetized rats

1987 ◽  
Vol 253 (6) ◽  
pp. H1335-H1341 ◽  
Author(s):  
T. L. Smith ◽  
T. G. Coleman ◽  
K. A. Stanek ◽  
W. R. Murphy
Keyword(s):  
Cardiac Output ◽  
Mean Arterial Pressure ◽  
Cardiac Index ◽  
Arterial Pressure ◽  
Stroke Volume ◽  
Diurnal Variation ◽  
Total Peripheral Resistance ◽  
Peripheral Resistance ◽  
Resistance Index ◽  
Total Peripheral Resistance Index

A new technique is described that allows minute-to-minute recordings of cardiac output and arterial pressure in unanesthetized rats for periods of 24 h and longer. Rats were instrumented with electromagnetic flow probes and arterial catheters. An electrical and hydraulic swivel was interposed between the rat and recording apparatus to allow free range of movement. Data were collected and analyzed once each minute by computer. Average 24-h values (mean +/- SD) for the following hemodynamic variables were determined in eight rats [expressed where appropriate as a function of body weight (BW)]: cardiac output (98.1 +/- 14.7 ml/min), cardiac index (29.2 +/- 4.4 ml.min-1.100 g BW-1), mean arterial pressure (92.5 +/- 7.8 mmHg), heart rate (347 +/- 45 beats/min), peak aortic flow (403 +/- 32 ml/min), stroke volume (282 +/- 26 microliters), stroke volume index (84.4 +/- 8.1 microliters/100 g BW), and total peripheral resistance index (3.26 +/- 0.46 mmHg.ml-1.min.100 g BW). These results provide a data base of hemodynamic values for unanesthetized adult, Sprague-Dawley male rats, which has not been previously available. In addition, cardiac index, mean arterial pressure, and total peripheral resistance index demonstrated diurnal variation. Diurnal variation contributed substantially to the overall variance observed within these variables. Hourly variance was also substantial and indicates the use of continuous recordings for short-term experiments.

Peripheral chemoreceptor control of cardiovascular function at rest and during exercise in heart failure patients

2015 ◽  
Vol 118 (7) ◽  
pp. 839-848 ◽  
Author(s):  
Heather Edgell ◽  
M. Sean McMurtry ◽  
Mark J. Haykowsky ◽  
Ian Paterson ◽  
Justin A. Ezekowitz ◽  
...  
Keyword(s):  
Heart Failure ◽  
Heart Rate ◽  
Ejection Fraction ◽  
Total Peripheral Resistance ◽  
Peripheral Resistance ◽  
Resistance Index ◽  
Cardiovascular Control ◽  
Peripheral Chemoreceptor ◽  
Dopamine Infusion ◽  
Total Peripheral Resistance Index

Peripheral chemoreceptor activity/sensitivity is enhanced in chronic heart failure (HF), and sensitivity is linked to greater mortality. This study aimed to determine the role of the peripheral chemoreceptor in cardiovascular control at rest and during exercise in HF patients and controls. Clinically stable HF patients ( n = 11; ejection fraction: 39 ± 5%) and risk-matched controls ( n = 10; ejection fraction: 65 ± 2%) performed randomized trials with or without dopamine infusion (2 μg·min−1·kg−1) at rest and during 40% maximal voluntary contraction handgrip (HG) exercise, and a resting trial of 2 min of inspired 100% oxygen. Both dopamine and hyperoxia were used to inhibit the peripheral chemoreceptor. At rest in HF patients, dopamine decreased ventilation ( P = 0.02), decreased total peripheral resistance index ( P = 0.003), and increased cardiac and stroke indexes ( P ≤ 0.01), yet there was no effect of dopamine on these variables in controls ( P ≥ 0.7). Hyperoxia lowered ventilation in HF ( P = 0.01), but not in controls ( P = 0.9), indicating suppression of the peripheral chemoreceptors in HF. However, no decrease of total peripheral resistance index was observed in HF. As expected, HG increased heart rate, ventilation, and brachial conductance of the nonexercising arm in controls and HF patients. During dopamine infusion, there were no changes in mean arterial pressure, heart rate, or ventilation responses to HG in either group ( P ≥ 0.26); however, brachial conductance increased with dopamine in the control group ( P = 0.004), but decreased in HF ( P = 0.02). Our findings indicate that the peripheral chemoreceptor contributes to cardiovascular control at rest in HF patients and during exercise in risk-matched controls.

Time-Course of Vascular Resistance Changes in Mineralocorticoid Hypertension of Man

1981 ◽  
Vol 61 (s7) ◽  
pp. 97s-100s ◽  
Author(s):  
G. J. Wenting ◽  
A. J. Man in 'T Veld ◽  
M. A. D. H. Schalekamp
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Vascular Resistance ◽  
Plasma Volume ◽  
High Resistance ◽  
Total Peripheral Resistance ◽  
Extracellular Volume ◽  
Peripheral Resistance ◽  
High Flow ◽  
Mean Blood Pressure

1. Repeated measurements of blood pressure, cardiac output (99mTc-labelled albumin dilution with single-probe precordial counting of radioactivity), plasma volume and extracellular volume were made in 20 subjects exposed to mineralocorticoid excess. Patients with aldosterone-producing adenoma (n = 14) were followed for 6 weeks during the recurrence of hypertension after spironolactone treatment had been stopped. Patients with adrenal insufficiency (n = 4) were followed for 6–9 weeks after treatment with dexamethasone (1 mg daily) and fludrocortisone (0.5 mg daily) was begun. Patients with severe orthostatic hypotension due to autonomic insufficiency (n = 2) were followed for 21 and 120 weeks while treated with fludrocortisone (0.25 mg daily). Measurements were made weekly during the first 6 weeks and with longer intervals thereafter. 2. All subjects showed increments of cardiac output, stroke volume, plasma volume and extracellular volume during the first 2 weeks with little or no increase in total peripheral resistance. Mean blood pressure rose from 104 ± 3 to 126 ± 5 mmHg (mean ± sem) (P < 0.001, n = 14) in that period in primary aldosteronism and from 85 ± 4 to 94 ± 6 mmHg (P > 0.05, n = 6) with fludrocortisone. 3. After 6 weeks hypertension was maintained by increased resistance in nine subjects, whereas cardiac output and plasma volume had returned towards normal (mean blood pressure at the end of the study 127 ± 4 mmHg). In the remainder hypertension was maintained by increased cardiac output and expanded plasma Volume for at least 6 weeks (mean blood pressure at the end of the study 131 ± 8 mmHg). The patients with the high-resistance pattern were older (56 ± 2 years) than the patients with the high-flow pattern (34 ± 2 years) (P < 0.01). 4. Mean blood pressure and extracellular fluid volume were positively correlated (r = 0.63, P < 0.001, n = 161). Cardiac output was positively correlated with plasma volume (r = 0.51, P < 0.001, n = 161), and total peripheral resistance was inversely correlated with the plasma volume/interstitial fluid volume ratio (r = 0.47, P < 0.001, n = 161). 5. The long duration of a high-flow state and the interindividual differences in progression of high-resistance hypertension argue against a cause-and-effect relation between flow and resistance through local metabolic factors (auto-regulation) as a hypertensive mechanism in sodium loading. The results are compatible with the view that fluid-shifts between the intravascular and extravascular compartments can influence the changes in cardiac output and resistance in early and sustained hypertension due to sodium overload. Cardiac output is increased when the proportion of fluid that is retained in the intravascular compartment is relatively high, and vascular resistance is increased when that proportion is relatively low.

Cardiovascular Effects of Stress During Acutely Increased Free Fatty Acids in a Randomized, Double-Blind, Cross-Over Study in Humans

2018 ◽  
Vol 50 (06) ◽  
pp. 478-484 ◽  
Author(s):  
Safoura Rezaei ◽  
Brigitte Litschauer ◽  
Gazaleh Gouya ◽  
Sabina Baumgartner-Parzer ◽  
Thomas Stulnig ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Cardiac Index ◽  
Free Fatty Acids ◽  
Total Peripheral Resistance ◽  
Peripheral Resistance ◽  
Resistance Index ◽  
Hemodynamic Parameters ◽  
Cold Face ◽  
Cold Face Test ◽  
Total Peripheral Resistance Index

AbstractIncreased free fatty acids stimulate sympathetic nervous system activity, impair endothelium-dependent vasodilation, and increase regional blood flow. The aim of this study was to assess if fatty acids acutely elevated by infusion of intralipid/heparin affect cardiovascular reactivity employing two stressors eliciting either a cardiac (Stroop test) or vascular (Cold Face test) dominated pressor response. Two stress tasks were performed in 20 healthy subjects (10 women, 10 men) before and during a 180-min intralipid/heparin or saline infusion as placebo on alternate trial days in a randomized crossover study design. Blood pressure, heart rate, cardiac index, and total peripheral resistance index were measured. At baseline, the Stroop test did not affect hemodynamic parameters, and the Cold Face test had an impact on hemodynamic parameters except for heart rate. Plasma fatty acids concentrations increased to 810% (t=11.0, p<0.001) of baseline and C-peptide increased by 17% (t=4.66, p<0.001) during intralipid/heparin infusion. This was paralleled by increased cardiac index (F=9.98; p<0.005 vs. saline) and reduced total peripheral resistance index (F=4.46; p<0.05 vs saline). There was no effect of intralipid/heparin or saline infusion on Stroop test or Cold Face test reactivity of hemodynamic parameters. An acute increase in free fatty acids does not affect the magnitude or pattern of stress response in healthy volunteers, but primarily alter the underlying cardiovascular tone by decreasing total peripheral resistance index and increasing cardiac index to maintain a constant blood pressure.

Hemodynamic responses to paraventricular nucleus disinhibition with bicuculline in conscious rats

1993 ◽  
Vol 265 (5) ◽  
pp. H1727-H1733 ◽  
Author(s):  
D. S. Martin ◽  
J. R. Haywood
Keyword(s):  
Mean Arterial Pressure ◽  
Cardiac Index ◽  
Arterial Pressure ◽  
Paraventricular Nucleus ◽  
Total Peripheral Resistance ◽  
Peripheral Resistance ◽  
Resistance Index ◽  
Volume Index ◽  
Hemodynamic Responses ◽  
Total Peripheral Resistance Index

The present study was undertaken to determine the hemodynamic responses associated with stimulation of the hypothalamic paraventricular nucleus (PVN). Male Sprague-Dawley rats (n = 21) were instrumented with guide cannulas directed bilaterally at the PVN, with an electromagnetic flow probe placed on the ascending aorta and with femoral venous and arterial catheters. Bicuculline methiodide (BMI, 2 mM) was infused bilaterally (100 nl/20 min) into the PVN region before and after treatment with the beta 1-adrenergic antagonist, metoprolol bitartrate (2 mg/kg iv) or the alpha 1-adrenergic receptor antagonist, prazosin hydrochloride (2 mg/kg iv). Infusion of BMI into the PVN increased mean arterial pressure by 17 +/- 2 mmHg, and heart rate rose by 91 +/- 8 beats/min. Cardiac index increased 17 +/- 3%, whereas total peripheral resistance index was not altered significantly. After metoprolol treatment, the mean arterial pressure response to BMI was similar to control (16 +/- 2 mmHg), but the tachycardia was reduced significantly (10 +/- 4 beats/min). In addition, the blood flow response was changed qualitatively. Total peripheral resistance increased 13 +/- 3%, whereas the cardiac index response was abolished (1 +/- 2%). After prazosin treatment, BMI administration into the PVN failed to increase arterial pressure (-1 +/- 4 mmHg). Nevertheless, the BMI infusion was associated with significant hemodynamic effects. Total peripheral resistance index decreased (-24 +/- 6%), whereas cardiac index and stroke volume index increased 34 +/- 8 and 17 +/- 5%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Elevated Blood Pressure in Adolescence Is Attributable to a Combination of Elevated Cardiac Output and Total Peripheral Resistance

Hypertension ◽  
2018 ◽  
Vol 72 (5) ◽  
pp. 1103-1108 ◽  
Author(s):  
Chloe Park ◽  
Abigail Fraser ◽  
Laura D. Howe ◽  
Siana Jones ◽  
George Davey Smith ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Total Peripheral Resistance ◽  
Peripheral Resistance ◽  
Elevated Blood Pressure ◽  
Elevated Blood

Long-term hemodynamic actions of atrial natriuretic factor (99-126) in conscious sheep

1988 ◽  
Vol 254 (4) ◽  
pp. H811-H815 ◽  
Author(s):  
D. G. Parkes ◽  
J. P. Coghlan ◽  
J. G. McDougall ◽  
B. A. Scoggins
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Blood Volume ◽  
Total Peripheral Resistance ◽  
Atrial Natriuretic Factor ◽  
Peripheral Resistance ◽  
Natriuretic Factor ◽  
Atrial Natriuretic

The hemodynamic and metabolic effects of long-term (5 day) infusion of human atrial natriuretic factor (ANF) were examined in conscious chronically instrumented sheep. Infusion of ANF at 20 micrograms/h, a rate below the threshold for an acute natriuretic effect, decreased blood pressure by 9 +/- 1 mmHg on day 5, associated with a fall in calculated total peripheral resistance. On day 1, ANF reduced cardiac output, stroke volume, and blood volume, effects that were associated with an increase in heart rate and calculated total peripheral resistance and a small decrease in blood pressure. On days 4 and 5 there was a small increase in urine volume and sodium excretion. On day 5 an increase in water intake and body weight was observed. No change was seen in plasma concentrations of renin, arginine vasopressin, glucose, adrenocorticotropic hormone, or protein. This study suggests that the short-term hypotensive effect of ANF results from a reduction in cardiac output associated with a fall in both stroke volume and effective blood volume. However, after 5 days of infusion, ANF lowers blood pressure via a reduction in total peripheral resistance.

scholarly journals The Key Role of Ambulatory Blood Pressure Monitoring in the Detection of Masked Hypertension and Other Phenomena in Frail Geriatric Patients

Medicina ◽  
2021 ◽  
Vol 57 (11) ◽  
pp. 1221
Author(s):  
Marek Koudelka ◽  
Eliška Sovová
Keyword(s):  
Blood Pressure ◽  
Arterial Hypertension ◽  
Ambulatory Blood Pressure Monitoring ◽  
Ambulatory Blood Pressure ◽  
Geriatric Patients ◽  
Blood Pressure Monitoring ◽  
Target Range ◽  
Masked Hypertension ◽  
Pressure Monitoring

Background and Objectives: This study aims to determine prevalence of masked uncontrolled hypertension (MUH) in frail geriatric patients with arterial hypertension and thus show the role of ambulatory blood pressure monitoring (ABPM) since hypertension occurs in more than 80% of people 60+ years and cardiovascular diseases are the main cause of death worldwide. Despite modern pharmacotherapy, use of combination therapy and normal office blood pressure (BP), patients’ prognoses might worsen due to inadequate therapy (never-detected MUH). Materials and Methods: 118 frail geriatric patients (84.2 ± 4.4 years) treated for arterial hypertension with office BP < 140/90 mmHg participated in the study. 24-h ABPM and clinical examination were performed. Results: Although patients were normotensive in the office, 24-h measurements showed that BP values in 72% of hypertensives were not in the target range: MUH was identified in 47 (40%) patients during 24 h, in 48 (41%) patients during daytime and nocturnal hypertension in 60 (51%) patients. Conclusions: ABPM is essential for frail geriatric patients due to high prevalence of MUH, which cannot be detected based on office BP measurements. ABPM also helps to detect exaggerated morning surge, isolated systolic hypertension, dipping/non-dipping, and set and properly manage adequate treatment, which reduces incidence of cardiovascular events and contributes to decreasing the financial burden of society.

Sign in / Sign up

Export Citation Format

Share Document