The effects of malnutrition on cardiac function in African children

ObjectiveCardiac dysfunction may contribute to high mortality in severely malnourished children. Our objective was to assess the effect of malnutrition on cardiac function in hospitalised African children.DesignProspective cross-sectional study.SettingPublic referral hospital in Blantyre, Malawi.PatientsWe enrolled 272 stable, hospitalised children ages 6–59 months, with and without WHO-defined severe acute malnutrition.Main outcome measuresCardiac index, heart rate, mean arterial pressure, stroke volume index and systemic vascular resistance index were measured by the ultrasound cardiac output monitor (USCOM, New South Wales, Australia). We used linear regression with generalised estimating equations controlling for age, sex and anaemia.ResultsOur primary outcome, cardiac index, was similar between those with and without severe malnutrition: difference=0.22 L/min/m2 (95% CI −0.08 to 0.51). No difference was found in heart rate or stroke volume index. However, mean arterial pressure and systemic vascular resistance index were lower in children with severe malnutrition: difference=−8.6 mm Hg (95% CI −12.7 to −4.6) and difference=−200 dyne s/cm5/m2 (95% CI −320 to −80), respectively.ConclusionsIn this largest study to date, we found no significant difference in cardiac function between hospitalised children with and without severe acute malnutrition. Further study is needed to determine if cardiac function is diminished in unstable malnourished children.

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Mechanisms contributing to hypotension after anesthetic induction with sufentanil, propofol, and rocuronium: a prospective observational study

Journal of Clinical Monitoring and Computing ◽

10.1007/s10877-021-00653-9 ◽

2021 ◽

Author(s):

Bernd Saugel ◽

Elisa-Johanna Bebert ◽

Luisa Briesenick ◽

Phillip Hoppe ◽

Gillis Greiwe ◽

...

Keyword(s):

Heart Rate ◽

Arterial Pressure ◽

Stroke Volume ◽

Systemic Vascular Resistance ◽

Vascular Resistance ◽

Resistance Index ◽

Stroke Volume Index ◽

Volume Index ◽

Systemic Vascular Resistance Index ◽

Anesthetic Induction

AbstractIt remains unclear whether reduced myocardial contractility, venous dilation with decreased venous return, or arterial dilation with reduced systemic vascular resistance contribute most to hypotension after induction of general anesthesia. We sought to assess the relative contribution of various hemodynamic mechanisms to hypotension after induction of general anesthesia with sufentanil, propofol, and rocuronium. In this prospective observational study, we continuously recorded hemodynamic variables during anesthetic induction using a finger-cuff method in 92 non-cardiac surgery patients. After sufentanil administration, there was no clinically important change in arterial pressure, but heart rate increased from baseline by 11 (99.89% confidence interval: 7 to 16) bpm (P < 0.001). After administration of propofol, mean arterial pressure decreased by 23 (17 to 28) mmHg and systemic vascular resistance index decreased by 565 (419 to 712) dyn*s*cm−5*m2 (P values < 0.001). Mean arterial pressure was < 65 mmHg in 27 patients (29%). After propofol administration, heart rate returned to baseline, and stroke volume index and cardiac index remained stable. After tracheal intubation, there were no clinically important differences compared to baseline in heart rate, stroke volume index, and cardiac index, but arterial pressure and systemic vascular resistance index remained markedly decreased. Anesthetic induction with sufentanil, propofol, and rocuronium reduced arterial pressure and systemic vascular resistance index. Heart rate, stroke volume index, and cardiac index remained stable. Post-induction hypotension therefore appears to result from arterial dilation with reduced systemic vascular resistance rather than venous dilation or reduced myocardial contractility.

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Fractional spinal anesthesia and systemic hemodynamics in frail elderly hip fracture patients

10.21203/rs.3.rs-1053831/v1 ◽

2021 ◽

Author(s):

Fredrik Olsen ◽

Mathias Hård af Segerstad ◽

Keti Dalla ◽

Sven-Erik Ricksten ◽

Bengt Nellgård

Keyword(s):

Heart Rate ◽

Cardiac Output ◽

Hip Fracture ◽

Spinal Anesthesia ◽

Resistance Index ◽

Stroke Volume Index ◽

Volume Index ◽

Systemic Vascular Resistance Index ◽

Hemodynamic Effects ◽

Systemic Hemodynamic

Abstract Background: Aging and frailty make the elderly patients susceptible to hypotension following spinal anesthesia. The systemic hemodynamic effects of spinal anesthesia are not well known. In this study, we examine the systemic hemodynamic effects of fractional spinal anesthesia following intermittent microdosing of a local anesthetic and an opioid.Methods: We included 15 patients aged over 65 with considerable comorbidities, planned for emergency hip fracture repair. Patients received a spinal catheter and cardiac output monitoring using the LiDCOplus system. Invasive mean arterial pressure (MAP), cardiac index, systemic vascular resistance index, heart rate and stroke volume index were registered. Two doses of bupivacaine 2.25 mg and fentanyl 15µg were administered with 25 minutes in between. Hypotension was defined as a fall in MAP by >30% or a MAP <65 mmHgResults: The incidence of hypotension was 30%. Hypotensive patients (n=5) were treated with low doses of norepinephrine (0.003-0.12 µg/kg/min). MAP showed a maximum reduction of 17% at 10 minutes after the first dose. Cardiac index, systemic vascular resistance index and stroke volume index decreased by 10%, 6%, and 7%, respectively, while heart rate was unchanged over time. After the first dose, none of the systemic haemodynamic variables were affected.Conclusion: Fractional spinal anesthesia causes a low incidence of hypotension, induced mainly by a systemic venodilation, causing a decrease in venous return and fall in cardiac output. Our results show that fractional spinal anesthesia is a safe technique from a hemodynamic point of view and is probably underutilized in high-risk, elderly hip fracture patients

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CARDIAC FUNCTION DURING MINI-INVASIVE REPAIR OF PECTUS EXCAVATUM WITH THE NUSS PROCEDURE

Wiadomości Lekarskie ◽

10.36740/wlek202108106 ◽

2021 ◽

Vol 74 (8) ◽

pp. 1809-1815

Author(s):

Ulbolhan A. Fesenko ◽

Ivan Myhal

Keyword(s):

Heart Rate ◽

Cardiac Output ◽

Cardiac Index ◽

Stroke Volume ◽

Cardiac Function ◽

Epidural Anaesthesia ◽

Pectus Excavatum ◽

Stroke Volume Index ◽

Volume Index ◽

Nuss Procedure

The aim of the study was to analyze cardiac function during Nuss procedure under the combination of general anesthesia with different variants of the regional block. Materials and methods: The observative prospective study included 60 adolescents (boys/girls=47/13) undergone Nuss procedure for pectus excavatum correction under the combination of general anaesthesia and regional blocks. The patients were randomized into three groups (n=20 in each) according to the perioperative regional analgesia technique: standart epidural anaesthesia (SEA), high epidural anaesthesia (HEA) and bilateral paravertebral anaesthesia (PVA). The following parameters of cardiac function were analyzed: heart rate, estimated cardiac output (esCCO), cardiac index (esCCI), stroke volume (esSV) and stroke volume index (esSVI) using non-invasive monitoring. Results: Induction of anesthesia and regional blocks led to a significant decrease in esCCO (-9.4%) and esCCI (-9.8%), while esSV and esSVI remained almost unchanged in all groups (H=4.9; p=0.09). At this stage, the decrease in cardiac output was mainly due to decreased heart rate. At the stage of sternal elevation we found an increase in esSV, which was more pronounced in the groups of epidural blocks (+23.1% in HEA and +18.5% in SEA). After awakening from anesthesia and tracheal extubation esSV was by 11% higher than before surgery without ingergroup difference. Conclusions: The Nuss procedure for pectus excavatum correction lead to improved cardiac function. increase in stroke volume and its index were more informative than cardiac output and cardiac index which are dependent on heart rate that is under the influence of anaesthesia technique.

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Increased oxygen uptake and utilization in the peripheral muscles, rather than cardiac function reserve, may be determinants of increased peak VO2 by cardiac rehabilitation in heart failure

European Heart Journal ◽

10.1093/ehjci/ehaa946.1069 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

H Hasegawa ◽

T Kono ◽

K Sakane ◽

T Matsuoka ◽

A Soyama ◽

...

Keyword(s):

Heart Failure ◽

Oxygen Uptake ◽

Cardiac Function ◽

Cardiac Rehabilitation ◽

Systolic Pressure ◽

Resistance Index ◽

Stroke Volume Index ◽

Peak Oxygen Consumption ◽

Volume Index ◽

Peak Vo2

Abstract Background Peak oxygen consumption (peak VO2) is a major prognostic parameter in heart failure (HF). Previous studies have shown a relationship between peak VO2 and impaired oxygen uptake and utilization in the peripheral muscles. The purpose of this study was to clarify the determinant of increased peak VO2 by cardiac rehabilitation (CR) in patients with HF. Methods We performed echocardiography during upright ramp bicycle cardiopulmonary exercise test in 30 HF patients (61±1 years of age, 80% male) before and 6 months after CR. HR reserve was determined as the change in HR from rest to peak exercise, expressed as a percentage of the predicted maximal HR reserve. Elastance index (EAI) and LV end-systolic elastance index (ELVI) were derived as the ratio of end-systolic pressure to stroke volume index and end-systolic volume index, respectively. End-systolic pressure was estimated from the equation 0.9 × brachial systolic blood pressure. Ventriculo-arterial coupling (VAC) was calculated as the quotient of EAI and ELVI. The ratio of LDEDVI to E/e' mean was used to evaluate LV diastolic compliance. Systemic vascular resistance index was calculated as mean arterial pressure divided by echocardiography calculated cardiac index and multiplied by 80. The arterial venous oxygen content difference (C (A-V) O2 gradient) was calculated by using the Fick equation as: VO2/echocardiography calculated cardiac output. Results Peak VO2 and C (A-V) O2 gradient were increased by CR. However, heart rate reserve, systolic reserve, VAC, diastolic reserve and vasodilation reserve were unchanged by CR (Table 1). Conclusions Increased oxygen uptake and utilization in the peripheral muscles, rather than cardiac function reserve, may be determinants of increased peak VO2 by CR in HF. Table 1 Funding Acknowledgement Type of funding source: None

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A proof of principle study of atomoxetine for the prevention of vasovagal syncope: the Prevention of Syncope Trial VI

EP Europace ◽

10.1093/europace/euz250 ◽

2019 ◽

Vol 21 (11) ◽

pp. 1733-1741 ◽

Cited By ~ 4

Author(s):

Robert S Sheldon ◽

Lucy Lei ◽

Juan C Guzman ◽

Teresa Kus ◽

Felix A Ayala-Paredes ◽

...

Keyword(s):

Cardiac Index ◽

Stroke Volume ◽

Vasovagal Syncope ◽

Resistance Index ◽

Stroke Volume Index ◽

Study Drug ◽

Norepinephrine Transporter ◽

Volume Index ◽

Head Up Tilt ◽

Invasive Techniques

Abstract Aims There are few effective therapies for vasovagal syncope (VVS). Pharmacological norepinephrine transporter (NET) inhibition increases sympathetic tone and decreases tilt-induced syncope in healthy subjects. Atomoxetine is a potent and highly selective NET inhibitor. We tested the hypothesis that atomoxetine prevents tilt-induced syncope. Methods and results Vasovagal syncope patients were given two doses of study drug [randomized to atomoxetine 40 mg (n = 27) or matched placebo (n = 29)] 12 h apart, followed by a 60-min drug-free head-up tilt table test. Beat-to-beat heart rate (HR), blood pressure (BP), and cardiac haemodynamics were recorded using non-invasive techniques and stroke volume modelling. Patients were 35 ± 14 years (73% female) with medians of 12 lifetime and 3 prior year faints. Fewer subjects fainted with atomoxetine than with placebo [10/29 vs. 19/27; P = 0.003; risk ratio 0.49 (confidence interval 0.28–0.86)], but equal numbers of patients developed presyncope or syncope (23/29 vs. 21/27). Of patients who developed only presyncope, 87% (13/15) had received atomoxetine. Patients with syncope had lower nadir mean arterial pressure than subjects with only presyncope (39 ± 18 vs. 69 ± 18 mmHg, P < 0.0001), and this was due to lower trough HRs in subjects with syncope (67 ± 30 vs. 103 ± 32 b.p.m., P = 0.006) and insignificantly lower cardiac index (2.20 ± 1.36 vs. 2.84 ± 1.05 L/min/m2, P = 0.075). There were no significant differences in stroke volume index (32 ± 6 vs. 35 ± 5 mL/m2, P = 0.29) or systemic vascular resistance index (2156 ± 602 vs. 1790 ± 793 dynes*s/cm5*m2, P = 0.72). Conclusion Norepinephrine transporter inhibition significantly decreased the risk of tilt-induced syncope in VVS subjects, mainly by blunting reflex bradycardia, thereby preventing final falls in cardiac index and BP.

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Survival and predictors of mortality among severe acute malnourished under-five children admitted at Felege-Hiwot comprehensive specialized hospital, northwest, Ethiopia: a retrospective cohort study

BMC Pediatrics ◽

10.1186/s12887-021-02651-x ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Amare Kassaw ◽

Desalegne Amare ◽

Minyichil Birhanu ◽

Aragaw Tesfaw ◽

Shegaw Zeleke ◽

...

Keyword(s):

Public Health ◽

Oxygen Saturation ◽

Retrospective Cohort ◽

Severe Acute Malnutrition ◽

Acute Malnutrition ◽

Altered Consciousness ◽

Time To Death ◽

Under Five ◽

Predictors Of Mortality ◽

Malnourished Children

Abstract Background Malnutrition is still a global public health problem contributing for under-five morbidity and mortality. The case is similar in Ethiopia in which severe acute malnutrition is the major contributor to mortality being an underlying cause for nearly 45% of under-five deaths. However, there is no recent evidence that shows the time to death and public health importance of oxygen saturation and chest in drawing in the study area. Therefore, estimated time to death and its predictors can provide an input for program planners and decision-makers. Methods A facility -based retrospective cohort study was conducted among 488 severe acute malnourished under-five children admitted from the 1st of January 2016 to the 30th of December 2019. The study participants were selected by using simple random sampling technique. Data were entered in to Epi-Data version 3.1 and exported to STATA version15 statistical software for further analysis. The Kaplan Meier was used to estimate cumulative survival probability and a log-rank test was used to compare the survival time between different categories of explanatory variables. The Cox-proportional hazard regression model was fitted to identify predictors of mortality. P-value< 0.05 was used to declare statistical significance. Results Out of the total 488 randomly selected charts of children with severe acute malnutrition, 476 records were included in the final analysis. A total of 54(11.34%) children died with an incidence rate of 9.1death /1000 person- days. Failed appetite test (AHR: 2.4; 95%CI: 1.26, 4.67), altered consciousness level at admission (AHR: 2.4; 95%CI: 1.08, 4.67), oxygen saturation below 90% (AHR: 3.3; 95%CI: 1.40, 7.87), edema (AHR 2.9; 95%CI: 1.45, 5.66) and HIV infection (AHR: 2.8; 95%CI: 1.24, 6.36) were predictors of mortality for children diagnosed with severe acute malnutrition. Conclusion The overall survival status of severe acute malnourished children was low as compared to national sphere standards and previous reports in the literature. The major predictors of mortality were oxygen saturation below 90%, altered consciousness, HIV infection, edema and failed appetite test. Therefore, early screening of complications, close follow up and regular monitoring of sever acute malnourished children might improve child survival rate.

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Empagliflozin does not change cardiac index nor systemic vascular resistance but rapidly improves left ventricular filling pressure in patients with type 2 diabetes: a randomized controlled study

Cardiovascular Diabetology ◽

10.1186/s12933-020-01175-5 ◽

2021 ◽

Vol 20 (1) ◽

Author(s):

Matthias Rau ◽

Kirsten Thiele ◽

Niels-Ulrik Korbinian Hartmann ◽

Alexander Schuh ◽

Ertunc Altiok ◽

...

Keyword(s):

Cardiac Index ◽

Systemic Vascular Resistance ◽

Vascular Resistance ◽

Resistance Index ◽

Stroke Volume Index ◽

Left Ventricular ◽

Volume Index ◽

Hemodynamic Parameters ◽

Mitral Inflow ◽

Ventricular Filling Pressure

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)

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Empagliflozin does not change cardiac index nor systemic vascular resistance but rapidly improves left ventricular filling pressure in patients with type 2 diabetes: a randomized controlled study

10.21203/rs.3.rs-45927/v2 ◽

2020 ◽

Author(s):

Matthias Rau ◽

Kirsten Thiele ◽

Niels-Ulrik Korbinian Hartmann ◽

Alexander Schuh ◽

Ertunc Altiok ◽

...

Keyword(s):

Cardiac Index ◽

Systemic Vascular Resistance ◽

Vascular Resistance ◽

Resistance Index ◽

Stroke Volume Index ◽

Left Ventricular ◽

Volume Index ◽

Hemodynamic Parameters ◽

Mitral Inflow ◽

Ventricular Filling Pressure

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.

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Effects of Normoxia, Hyperoxia, and Mild Hypoxia on Macro-Hemodynamics and the Skeletal Muscle Microcirculation in Anesthetised Rats

Frontiers in Medicine ◽

10.3389/fmed.2021.672257 ◽

2021 ◽

Vol 8 ◽

Author(s):

Elisa Damiani ◽

Erika Casarotta ◽

Fiorenza Orlando ◽

Andrea Carsetti ◽

Claudia Scorcella ◽

...

Keyword(s):

Skeletal Muscle ◽

Negative Impact ◽

Resistance Index ◽

Stroke Volume Index ◽

Microvascular Density ◽

Vessel Density ◽

Volume Index ◽

Flow Index ◽

Flow Quality ◽

Mild Hypoxia

Objectives: Excessive oxygen (O2) administration may have a negative impact on tissue perfusion by inducing vasoconstriction and oxidative stress. We aimed to evaluate the effects of different inhaled oxygen fractions (FiO2) on macro-hemodynamics and microvascular perfusion in a rat model.Methods: Isoflurane-anesthetised spontaneously breathing male Wistar rats were equipped with arterial (carotid artery) and venous (jugular vein) catheters and tracheotomy, and randomized into three groups: normoxia (FiO2 21%, n = 6), hyperoxia (FiO2 100%, n = 6) and mild hypoxia (FiO2 15%, n = 6). Euvolemia was maintained by infusing Lactate Ringer solution at 10 ml/kg/h. At hourly intervals for 4 h we collected measurements of: mean arterial pressure (MAP); stroke volume index (SVI), heart rate (HR), respiratory rate (by means of echocardiography); arterial and venous blood gases; microvascular density, and flow quality (by means of sidestream dark field videomicroscopy on the hindlimb skeletal muscle).Results: MAP and systemic vascular resistance index increased with hyperoxia and decreased with mild hypoxia (p < 0.001 in both cases, two-way analysis of variance). Hyperoxia induced a reduction in SVI, while this was increased in mild hypoxia (p = 0.002). The HR increased under hyperoxia (p < 0.05 vs. normoxia at 3 h). Cardiax index, as well as systemic O2 delivery, did not significantly vary in the three groups (p = 0.546 and p = 0.691, respectively). At 4 h, microvascular vessel surface (i.e., the percentage of tissue surface occupied by vessels) decreased by 29 ± 4% in the hyperoxia group and increased by 19 ± 7 % in mild hypoxia group (p < 0.001). Total vessel density and perfused vessel density showed similar tendencies (p = 0.003 and p = 0.005, respectively). Parameters of flow quality (microvascular flow index, percentage of perfused vessels, and flow heterogeneity index) remained stable and similar in the three groups.Conclusions: Hyperoxia induces vasoconstriction and reduction in skeletal muscle microvascular density, while mild hypoxia has an opposite effect.

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Stress Echocardiography in Hyperthyroidism

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jcem.84.7.5830 ◽

1999 ◽

Vol 84 (7) ◽

pp. 2308-2313 ◽

Cited By ~ 16

Author(s):

George J. Kahaly ◽

Stephan Wagner ◽

Jana Nieswandt ◽

Susanne Mohr-Kahaly ◽

Thomas J. Ryan

Keyword(s):

Heart Rate ◽

Ejection Fraction ◽

Stroke Volume ◽

Stress Echocardiography ◽

Maximal Exercise ◽

Stroke Volume Index ◽

Work Load ◽

Left Ventricular ◽

Volume Index ◽

Systolic Volume

Exertion symptoms occur frequently in subjects with hyperthyroidism. Using stress echocardiography, exercise capacity and global left ventricular function can be assessed noninvasively. To evaluate stress-induced changes in cardiovascular function, 42 patients with untreated thyrotoxicosis were examined using exercise echocardiography. Studies were performed during hyperthyroidism, after treatment with propranolol, and after restoration of euthyroidism. Twenty- two healthy subjects served as controls. Ergometry was performed with patients in a semisupine position using a continuous ramp protocol starting at 20 watts/min. In contrast to control and euthyroidism, the change in end-systolic volume index from rest to maximal exercise was lower in hyperthyroidism. At rest, the stroke volume index, ejection fraction, and cardiac index were significantly increased in hyperthyroidism, but exhibited a blunted response to exercise, which normalized after restoration of euthyroidism. Propranolol treatment also led to a significant increase of delta (Δ) stroke volume index. Maximal work load and Δ heart rate were markedly lower in hyper- vs. euthyroidism. Compared to the control value, systemic vascular resistance was lowered by 36% in hyperthyroidism at rest, but no further decline was noted at maximal exercise. The Δ stroke volume index, Δ ejection fraction, Δ heart rate, and maximal work load were significantly reduced in severe hyperthyroidism. Negative correlations between free T3 and diastolic blood pressure, maximal work load, Δ heart rate, and Δ ejection fraction were noted. Thus, in hyperthyroidism, stress echocardiography revealed impaired chronotropic, contractile, and vasodilatatory cardiovascular reserves, which were reversible when euthyroidism was restored.

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