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 ◽  
...  

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.

1987 ◽  
Vol 253 (6) ◽  
pp. H1335-H1341 ◽  
Author(s):  
T. L. Smith ◽  
T. G. Coleman ◽  
K. A. Stanek ◽  
W. R. Murphy

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.


1993 ◽  
Vol 265 (5) ◽  
pp. H1727-H1733 ◽  
Author(s):  
D. S. Martin ◽  
J. R. Haywood

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)


2015 ◽  
Vol 118 (7) ◽  
pp. 839-848 ◽  
Author(s):  
Heather Edgell ◽  
M. Sean McMurtry ◽  
Mark J. Haykowsky ◽  
Ian Paterson ◽  
Justin A. Ezekowitz ◽  
...  

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.


2020 ◽  
Author(s):  
Meredith McAdams ◽  
L Parker Gregg ◽  
Rong Lu ◽  
Michael Concepcion ◽  
Swati Lederer ◽  
...  

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.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Matthias Rau ◽  
Kirsten Thiele ◽  
Niels-Ulrik Korbinian Hartmann ◽  
Alexander Schuh ◽  
Ertunc Altiok ◽  
...  

Abstract Background In the EMPA-REG OUTCOME trial (Empagliflozin Cardiovascular Outcome Event Trial) treatment with the sodium-glucose cotransporter-2 (SGLT2) inhibitor empagliflozin significantly reduced heart failure hospitalization (HHF) in patients with type 2 diabetes mellitus (T2D) and established cardiovascular disease. The early separation of the HHF event curves within the first 3 months of the trial suggest that immediate hemodynamic effects may play a role. However, hitherto no data exist on early effects of SGLT2 inhibitors on hemodynamic parameters and cardiac function. Thus, this study examined early and delayed effects of empagliflozin treatment on hemodynamic parameters including systemic vascular resistance index, cardiac index, and stroke volume index, as well as echocardiographic measures of cardiac function. Methods In this placebo-controlled, randomized, double blind, exploratory study patients with T2D were randomized to empagliflozin 10 mg or placebo for a period of 3 months. Hemodynamic and echocardiographic parameters were assessed after 1 day, 3 days and 3 months of treatment. Results Baseline characteristics were not different in the empagliflozin (n = 22) and placebo (n = 20) group. Empagliflozin led to a significant increase in urinary glucose excretion (baseline: 7.3 ± 22.7 g/24 h; day 1: 48.4 ± 34.7 g/24 h; p < 0.001) as well as urinary volume (1740 ± 601 mL/24 h to 2112 ± 837 mL/24 h; p = 0.011) already after one day compared to placebo. Treatment with empagliflozin had no effect on the primary endpoint of systemic vascular resistance index, nor on cardiac index, stroke volume index or pulse rate at any time point. In addition, echocardiography showed no difference in left ventricular systolic function as assessed by left ventricular ejections fraction and strain analysis. However, empagliflozin significantly improved left ventricular filling pressure as assessed by a reduction of early mitral inflow velocity relative to early diastolic left ventricular relaxation (E/eʹ) which became significant at day 1 of treatment (baseline: 9.2 ± 2.6; day 1: 8.5 ± 2.2; p = 0.005) and remained apparent throughout the study. This was primarily attributable to reduced early mitral inflow velocity E (baseline: 0.8 ± 0.2 m/s; day 1: 0.73 ± 0.2 m/sec; p = 0.003). Conclusions Empagliflozin treatment of patients with T2D has no significant effect on hemodynamic parameters after 1 or 3 days, nor after 3 months, but leads to rapid and sustained significant improvement of diastolic function. Trial registration EudraCT Number: 2016-000172-19; date of registration: 2017-02-20 (clinicaltrialregister.eu)


2020 ◽  
Author(s):  
Matthias Rau ◽  
Kirsten Thiele ◽  
Niels-Ulrik Korbinian Hartmann ◽  
Alexander Schuh ◽  
Ertunc Altiok ◽  
...  

Abstract Background: In the EMPA-REG OUTCOME trial (Empagliflozin Cardiovascular Outcome Event Trial) treatment with the sodium-glucose cotransporter-2 (SGLT2) inhibitor empagliflozin significantly reduced heart failure hospitalization (HHF) in patients with type 2 diabetes mellitus (T2D) and established cardiovascular disease. The early separation of the HHF event curves within the first 3 months of the trial suggest that immediate hemodynamic effects may play a role. However, hitherto no data exist on early effects of SGLT2 inhibitors on hemodynamic parameters and cardiac function. Thus, this study examined early and delayed effects of empagliflozin treatment on hemodynamic parameters including systemic vascular resistance index, cardiac index, and stroke volume index, as well as echocardiographic measures of cardiac function.Methods: In this placebo-controlled, randomized, double blind, exploratory study patients with T2D were randomized to empagliflozin 10 mg or placebo for a period of 3 months. Hemodynamic and echocardiographic parameters were assessed after 1 day, 3 days and 3 months of treatment. Results: Baseline characteristics were not different in the empagliflozin (n=22) and placebo (n=20) group. Empagliflozin led to a significant increase in urinary glucose excretion (baseline: 7.3 ± 22.7 g/24 hrs; day 1: 48.4 ± 34.7 g/24 hrs; p<0.001) as well as urinary volume (1740 ± 601 mL/24 hrs to 2112 ± 837 mL/24 hrs; p=0.011) already after one day compared to placebo. Treatment with empagliflozin had no effect on the primary endpoint of systemic vascular resistance index, nor on cardiac index, stroke volume index or pulse rate at any time point. In addition, echocardiography showed no difference in left ventricular systolic function as assessed by left ventricular ejections fraction and strain analysis. However, empagliflozin significantly improved left ventricular filling pressure as assessed by a reduction of early mitral inflow velocity relative to early diastolic left ventricular relaxation (E/e’) which became significant at day 1 of treatment (baseline: 9.2 ± 2.6; day 1: 8.5 ± 2.2; p=0.005) and remained apparent throughout the study. This was primarily attributable to reduced early mitral inflow velocity E (baseline: 0.8 ± 0.2 m/sec; day 1: 0.73 ± 0.2 m/sec; p=0.003). Conclusions: Empagliflozin treatment of patients with T2D has no significant effect on hemodynamic parameters after 1 or 3 days, nor after 3 months, but leads to rapid and sustained significant improvement of diastolic function.


1978 ◽  
Vol 55 (s4) ◽  
pp. 69s-71s ◽  
Author(s):  
Y. Miura ◽  
K. Kobayashi ◽  
H. Sakuma ◽  
H. Tomioka ◽  
M. Adachi ◽  
...  

1. Plasma noradrenaline concentrations and haemodynamic status were simultaneously studied in young patients with uncomplicated essential hypertension and in age-matched normal controls. 2. Resting plasma noradrenaline in the controls tended to increase slightly, but progressively, with age. The hypertensive subjects had significantly higher plasma noradrenaline concentrations than those in the controls, but these values did not show any age-related variation. The response of plasma noradrenaline to the standing position tended to increase with age in the controls, whereas plasma noradrenaline in the hypertensive subjects showed a wide range of responses without any fixed relationship with age. 3. The cardiac index was significantly greater in the labile hypertensive subjects than in the controls, whereas total peripheral resistance was significantly greater in the sustained hypertensive subjects than in the labile patients and in the controls. Mean arterial pressure in these patients was closely related with the values of total peripheral resistance rather than with the cardiac index. 4. Of the patients with raised plasma noradrenaline 80% showed significantly increased values of either total peripheral resistance or cardiac index. Plasma noradrenaline was correlated significantly to total peripheral resistance, and marginally to mean arterial pressure. 5. These findings support the view that sympathetic nervous overactivity is an important factor underlying the haemodynamic findings in these patients.


Pteridines ◽  
2003 ◽  
Vol 14 (3) ◽  
pp. 94-101 ◽  
Author(s):  
Remigiusz Zieba ◽  
Elzbieta Czarnecka ◽  
Małgorzata Wągrowska-Danilewicz ◽  
Malgorzata Dzielska-Olczak ◽  
Julita Graczyk

Abstract The aim of this study was to establish the effect of naturally occurring antioxidant - carnosine - on the doxorubicin induced cardiotoxicity in a rabbit model. For this purpose we evaluated the influence of doxorubicin administration alone and in a combined therapy with carnosine on the haemodynamic parameters and on the degree of cardiac muscle cells alterations in rabbits. The rabbits were divided into four groups. One group of rabbits was injccted with doxorubicin in a dose of 2 mg kg-1 weekly for 7 weeks to induce congestive heart failure. Another group of rabbits received the same doses of doxorubicin simultaneously with carnosine in a dose of 100 mg kg1 p.o. daily for 9 weeks. Administration of carnosine was started 1 week prior to the first dose of doxorubicin and was ended one week after the administration of the last dose of doxorubicin. The control groups of animals received 0.9% NaCl and carnosine alone. The following haemodynamic parameters were estimated: heart rate, mean arterial pressure, cardiac index, stroke index and total peripheral resistance. Registration of the haemodynamic parameters in rabbits was performed by Doppler method. Carnosine normalised the values of mean arterial pressure in rabbits receiving doxorubicin, and increased the values of cardiac index and stroke index. The influence of carnosine on total peripheral resistance was not statistically significant, but there was a decreasing tendency. The degree of cardiac muscle cell alterations was examined by light microscopy using Mean Total Score technique. The histopathological studies revealed smaller damage of cardiac muscle in rabbits which received doxorubicin and carnosine, in comparison to animals receiving doxorubicin alone. Carnosine seems to be car dioprotective during doxorubicin administration


1979 ◽  
Vol 57 (s5) ◽  
pp. 11s-13s ◽  
Author(s):  
G. L. Jennings ◽  
P. I. Korner ◽  
M. D. Esler

1. The haemodynamics of ten patients with essential hypertension were studied before treatment (study 1) and again 1 week after cessation of 1 year's antihypertensive drug therapy (study 2). On each occasion measurements of mean arterial pressure (MAP), cardiac index (CI) and total peripheral resistance index (TPRI) were made before and after ‘total’ pharmacological autonomic blockade (with intravenous propranolol, atropine, phentolamine and clonidine); measurements after ‘total’ autonomic blockade were used to assess the magnitude of the ‘non-autonomic’ component of TPRI, which reflects humoral or structural alterations in the vasculature. 2. The findings before ‘total’ autonomic blockade during study 2 showed that MAP was 18 ± 8 mmHg below the value (135 mmHg) observed during study 1 before treatment, and TPRI had fallen by 33% (P &lt; 0·05) and CI had increased by 23% (P &lt; 0·05). 3. After ‘total’ autonomic blockade the differences in the ‘non-autonomic’ components of the different variables were similar, with ‘non-autonomic’ MAP 14 ± 4 mmHg lower in study 2, TPRI 42% lower (P &lt; 0·005) and CI 28% higher. The value in ‘non-autonomic’ TPRI was now the same as values previously observed in normotensive subjects. 4. We conclude that after 1 year's successful treatment there is complete restoration of ‘non-autonomic’ TPRI as a secondary consequence of the blood pressure reduction.


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