Differential effects of endothelin-1 on isolated working rat hearts before and after ischaemia and reperfusion

Endothelin (ET) may have both detrimental (reduced coronary flow) and beneficial effects (positive inotrope, reduced arrhythmogenesis) following ischaemia. We examined the effects of ET on cardiac function during reperfusion following prolonged hypothermic cardioplegic arrest in a protocol mimicking cardiac transplantation. Isolated working rat hearts were perfused with Krebs buffer to which increasing concentrations of ET-1 or sarafotoxin S6c had been added. Identical experiments were performed after 4h of cardioplegic arrest at 4°C. Under pre-ischaemic conditions ET-1 caused a dose-dependent decrease in cardiac function compared with controls. In contrast, following ischaemia low doses of ET-1 (10-10 M) caused a significant and beneficial increase in cardiac output (109.1% versus 81.3%), dP/dt i.e. the rate of change of pressure with time (94.7% versus 75.6%) and stroke volume (100.3% versus 77.5%) compared with controls (P<0.05). At higher doses of ET-1 there was a detrimental effect on cardiac output, dP/dt and stroke volume similar to that seen prior to ischaemia. Sarafotoxin S6c had no significant effect pre or post ischaemia on any of the parameters measured compared with controls (P = not significant). ET-1 at low concentrations during reperfusion can improve the recovery of cardiac function mediated via ETA receptors. ET may play an important physiological role in the recovery of cardiac function following prolonged ischaemia.

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Postnatal hemodynamic changes in very-low-birthweight infants

Journal of Applied Physiology ◽

10.1152/jappl.1999.87.1.370 ◽

1999 ◽

Vol 87 (1) ◽

pp. 370-380 ◽

Cited By ~ 39

Author(s):

Toby Debra Yanowitz ◽

Alice C. Yao ◽

Karen D. Pettigrew ◽

John C. Werner ◽

William Oh ◽

...

Keyword(s):

Cardiac Output ◽

Stroke Volume ◽

Cardiac Function ◽

Low Birthweight ◽

Ductus Arteriosus ◽

Mesenteric Arteries ◽

Very Low Birthweight ◽

Hemodynamic Changes ◽

Before And After ◽

Very Low Birthweight Infants

The purpose of this study was to characterize postnatal changes in regional Doppler blood flow velocity (BFV) and cardiac function of very-low-birthweight infants and to examine factors that might influence these hemodynamic changes. Mean and end-diastolic BFV of the middle cerebral and superior mesenteric arteries, cardiac output, stroke volume, and fractional shortening were measured in 20 infants birthweight 1,002 ± 173 g, gestational age 28 ± 2 wk) at 6, 30, and 54 h after birth and before and after feedings on days 7 and 14. Postnatal increases in cerebral BFV, mesenteric BFV, and cardiac output were observed that were not associated with changes in blood pressure, hematocrit, pH, arterial[Formula: see text], or oxygen saturation. The postnatal pattern of relative vascular resistance (RVR) differed between the cerebral and mesenteric vasculatures. RVR decreased in the middle cerebral but not the superior mesenteric artery. Physiological patency of the ductus arteriosus did not alter postnatal hemodynamic changes. In response to feeding, mesenteric BFV and stroke volume increased, and mesenteric RVR and heart rate decreased. Postprandial responses were not affected by postnatal age or the age at which feeding was initiated. However, the initiation of enteral nutrition before 3 days of life was associated with higher preprandial mesenteric BFV and lower mesenteric RVR than was later initiation of feeding. We conclude that in very-low-birthweight infants over the first week of life 1) systemic, cerebral, and mesenteric hemodynamics exhibit region-specific changes; 2) asymptomatic ductus arteriosus patency and early feedings do not significantly influence these postnatal hemodynamic changes; and 3) cardiac function adapts to increase local mesenteric BFV in response to feedings.

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Effects of Cardiac Function with Postoperative Arteriovenous Fistula Blood Flow in Patients with Hemodialysis

Blood Purification ◽

10.1159/000458146 ◽

2017 ◽

Vol 44 (1) ◽

pp. 24-29 ◽

Cited By ~ 4

Author(s):

Keiichi Wakabayashi ◽

Hiroaki Io ◽

Junichiro Nakata ◽

Hirotaka Nakamoto ◽

Michiko Sato ◽

...

Keyword(s):

Blood Flow ◽

Body Weight ◽

Cardiac Output ◽

Ejection Fraction ◽

Stroke Volume ◽

Cardiac Function ◽

Arteriovenous Fistula ◽

Rate Of Change ◽

University Hospital ◽

Reduced Ejection Fraction

Background/Aims: This study was aimed at evaluating the effect of cardiac function with postoperative arteriovenous fistula (AVF) blood flow in hemodialysis (HD) patients. Methods: A total of 45 HD patients were examined at the Juntendo University Hospital. The AVF blood flow was measured using ultrasonography, and the cardiac function was measured using echocardiography. Correlation between these parameters and the rate of change in body weight (BW) was analyzed. Results: The number of postoperative days significantly correlated with the AVF blood flow, and it positively correlated with the stroke volume (SV). The postoperative AVF blood flow in patients with reduced ejection fraction (EF) was lower than that in patients with normal EF. The rate of change of BW negatively correlated with that of SV, positively correlated with cardiac output (CO), and positively correlated with CO in patients with an AVF blood flow of more than 1,000 mL/min. Conclusion: It appears that the cardiac function can be improved by controlling the BW even in patients with high AVF blood flow.

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Cardioprotection with esmolol-based cardioplegia for non-infarcted and infarcted rat hearts

European Journal of Cardio-Thoracic Surgery ◽

10.1093/ejcts/ezab117 ◽

2021 ◽

Author(s):

Alexander B Veitinger ◽

Audrey Komguem ◽

Lena Assling-Simon ◽

Martina Heep ◽

Julia Schipke ◽

...

Keyword(s):

Myocardial Infarction ◽

Cardiac Function ◽

Infarct Size ◽

Myocardial Infarct ◽

Lactate Production ◽

Left Ventricular ◽

Myocardial Infarct Size ◽

Cardioplegic Arrest ◽

Blood Cardioplegia ◽

Rat Hearts

Abstract OBJECTIVES Esmolol-based cardioplegic arrest offers better cardioprotection than crystalloid cardioplegia but has been compared experimentally with blood cardioplegia only once. We investigated the influence of esmolol crystalloid cardioplegia (ECCP), esmolol blood cardioplegia (EBCP) and Calafiore blood cardioplegia (Cala) on cardiac function, metabolism and infarct size in non-infarcted and infarcted isolated rat hearts. METHODS Two studies were performed: (i) the hearts were subjected to a 90-min cardioplegic arrest with ECCP, EBCP or Cala and (ii) a regional myocardial infarction was created 30 min before a 90-min cardioplegic arrest. Left ventricular peak developed pressure (LVpdP), velocity of contractility (dLVP/dtmax), velocity of relaxation over time (dLVP/dtmin), heart rate and coronary flow were recorded. In addition, the metabolic parameters were analysed. The infarct size was determined by planimetry, and the myocardial damage was determined by electron microscopy. RESULTS In non-infarcted hearts, cardiac function was better preserved with ECCP than with EBCP or Cala relative to baseline values (LVpdP: 100 ± 28% vs 86 ± 11% vs 57 ± 7%; P = 0.002). Infarcted hearts showed similar haemodynamic recovery for ECCP, EBCP and Cala (LVpdP: 85 ± 46% vs 89 ± 55% vs 56 ± 26%; P = 0.30). The lactate production with EBCP was lower than with ECCP (0.6 ± 0.7 vs 1.4 ± 0.5 μmol/min; P = 0.017). The myocardial infarct size and (ECCP vs EBCP vs Cala: 16 ± 7% vs 15 ± 9% vs 24 ± 13%; P = 0.21) the ultrastructural preservation was similar in all groups. CONCLUSIONS In non-infarcted rat hearts, esmolol-based cardioplegia, particularly ECCP, offers better myocardial protection than Calafiore. After an acute myocardial infarction, cardioprotection with esmolol-based cardioplegia is similar to that with Calafiore.

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Non-Invasive Scale Measurement of Cardiac Output Compared with the Gold-Standard Direct Fick Method: A Feasibility Study

10.1101/2021.03.28.21254243 ◽

2021 ◽

Author(s):

Daniel Yazdi ◽

Sarin Patel ◽

Suriya Sridaran ◽

Evan Wilson ◽

Sarah Smith ◽

...

Keyword(s):

Cardiac Output ◽

Stroke Volume ◽

Cardiac Function ◽

Exercise Test ◽

Gold Standard ◽

Cardiopulmonary Exercise Test ◽

Cardiac Monitoring ◽

Non Invasive ◽

Cardiopulmonary Exercise ◽

The Mean

AbstractBackgroundObjective markers of cardiac function are limited in the outpatient setting and may be beneficial for monitoring patients with chronic cardiac conditions.ObjectiveWe assess the accuracy of a scale, with the ability to capture ballistocardiography, electrocardiography, and impedance plethysmography signals from a patient’s feet while standing on the scale, in measuring stroke volume and cardiac output compared to the gold-standard direct Fick method.MethodsThirty-two patients with unexplained dyspnea undergoing level 3 invasive cardiopulmonary exercise test at a tertiary medical center were included in the final analysis. We obtained scale and direct Fick measurements of stroke volume and cardiac output before and immediately after invasive cardiopulmonary exercise test.ResultsStroke volume and cardiac output from a cardiac scale and the direct Fick method correlated with r = 0.81 and r = 0.85, respectively (P < 0.001 each). The mean absolute error of the scale estimated stroke volume was -1.58 mL, with a 95% limits of agreement (LOA) of -21.97 mL to 18.81 mL. The mean error for the scale estimated cardiac output was -0.31 L/min, with a 95% LOA of -2.62 L/min to 2.00 L/min. The change in stroke volume and cardiac output before and after exercise were 78.9% and 96.7% concordant, respectively between the two measuring methods.ConclusionsThis novel scale with cardiac monitoring abilities may allow for non-invasive, longitudinal measures of cardiac function. Using the widely accepted form factor of a bathroom scale, this method of monitoring can be easily integrated into a patient’s lifestyle.

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Nature Enhanced Meditation: Effects on Mindfulness, Connectedness to Nature, and Pro-Environmental Behavior

Environment and Behavior ◽

10.1177/0013916520952452 ◽

2020 ◽

pp. 001391652095245

Author(s):

Travis N. Ray ◽

Scott A. Franz ◽

Nicole L. Jarrett ◽

Scott M. Pickett

Keyword(s):

Natural Environment ◽

Environmental Behavior ◽

Rate Of Change ◽

Future Research ◽

Control Group ◽

Cross Sectional ◽

Connectedness To Nature ◽

Beneficial Effects ◽

Before And After

Previous research suggests that meditation, a mindfulness exercise, could result in increased connectedness to nature and pro-environmental behavior. Exposure to nature also is associated with these outcomes. It was hypothesized that meditation alongside stimuli reminiscent of the natural environment would produce enhanced effects. Participants ( N = 97) were randomly assigned to complete a 4-week online meditation program consisting of a guided meditation paired with either nature sounds (“nature group”) or spa-like sounds (“control group”). Mindfulness, connectedness to nature, and pro-environmental behavior were assessed before and after the program. Meditation, in general, produced increases in mindfulness, connectedness to nature, and pro-environmental behavior. Additionally, the nature group had a greater rate of change in connectedness to nature when compared to the control group. The results extend previous cross-sectional research by demonstrating the beneficial effects of meditation on pro-environmental behavior and its theorized mechanisms, which may be informative for future research and interventions.

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Orthostatic intolerance after spaceflight

Journal of Applied Physiology ◽

10.1152/jappl.1996.81.1.7 ◽

1996 ◽

Vol 81 (1) ◽

pp. 7-18 ◽

Cited By ~ 399

Author(s):

J. C. Buckey ◽

L. D. Lane ◽

B. D. Levine ◽

D. E. Watenpaugh ◽

S. J. Wright ◽

...

Keyword(s):

Heart Rate ◽

Cardiac Output ◽

Stroke Volume ◽

Space Shuttle ◽

Orthostatic Intolerance ◽

Peripheral Resistance ◽

Systemic Hemodynamic ◽

Vasoconstrictor Response ◽

Before And After ◽

Underlying Mechanisms

Orthostatic intolerance occurs commonly after spaceflight, and important aspects of the underlying mechanisms remain unclear. We studied 14 individuals supine and standing before and after three space shuttle missions of 9-14 days. After spaceflight, 9 of the 14 (64%) crew members could not complete a 10-min stand test that all completed preflight. Pre- and postflight supine hemodynamics were similar in both groups except for slightly higher systolic and mean arterial pressures preflight in the finishers [15 +/- 3.7 and 8 +/- 1.2 (SE) mmHg, respectively; P < 0.05]. Postflight, finishers and nonfinishers had equally large postural reductions in stroke volume (-47 +/- 3.7 and -48 +/- 3.3 ml, respectively) and increases in heart rate (35 +/- 6.6 and 51 +/- 5.2 beats/min, respectively). Cardiac output during standing was also similar (3.6 +/- 0.4 and 4.1 +/- 0.3 l/min, respectively). However, the finishers had a greater postflight vasoconstrictor response with higher total peripheral resistance during standing (22.3 +/- 1.2 units preflight and 29.4 +/- 2.3 units postflight) than did the nonfinishers (20.1 +/- 1.1 units preflight and 19.9 +/- 1.4 units postflight). We conclude that 1) the primary systemic hemodynamic event, i.e., the postural decrease in stroke volume, was similar in finishers and nonfinishers and 2) the heart rate response and cardiac output during standing were not significantly different, but 3) the postural vasoconstrictor response was significantly greater among the finishers (P < 0.01).

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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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Myocardial function in rat genetic models of low and high aerobic running capacity

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00367.2001 ◽

2002 ◽

Vol 282 (3) ◽

pp. R721-R726 ◽

Cited By ~ 8

Author(s):

John C. Barbato ◽

Soon Jin Lee ◽

Lauren Gerard Koch ◽

George T. Cicila

Keyword(s):

Cardiac Output ◽

Stroke Volume ◽

Cardiac Function ◽

Atp Hydrolysis ◽

Mrna Level ◽

Inbred Strains ◽

Left Ventricular ◽

Genetic Models ◽

Heart Preparation ◽

The Mean

We recently evaluated treadmill aerobic running capacity in 11 inbred strains of rats and found that isolated working left ventricular function correlated ( r = 0.86) with aerobic running capacity. Among these 11 strains the Buffalo (BUF) hearts produced the lowest and the DA hearts the highest isolated cardiac output. The goal of this study was to investigate the components of cardiac function (i.e., coronary flow, heart rates, stroke volume, contractile dynamics, and cross-bridge cycling) to characterize further the BUF and DA inbred strains as potential models of contrasting myocardial performance. Cardiac performance was assessed using the Langendorff-Neely working heart preparation. Isolated DA hearts were superior ( P< 0.05) to the BUF hearts for cardiac output (63%), stroke volume (60%), aortic +dP/d t (47%), and aortic −dP/d t(46%). The mean α/β-myosin heavy chain (MHC) isoform ratio for DA hearts was 21-fold higher relative to BUF hearts. At the steady-state mRNA level, DA hearts had a fivefold higher α/β-ratio than the BUF hearts. The mean rate of ATP hydrolysis by MHCs was 64% greater in DA compared with BUF ventricles. These data demonstrate that the BUF and DA strains can serve as genetic models of contrasting low and high cardiac function.

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Modification of alterations in cardiac function and sarcoplasmic reticulum by vanadate in ischemic-reperfused rat hearts

Journal of Applied Physiology ◽

10.1152/japplphysiol.00234.2005 ◽

2005 ◽

Vol 99 (3) ◽

pp. 999-1005 ◽

Cited By ~ 8

Author(s):

Satoshi Takeda ◽

Seibu Mochizuki ◽

Harjot K. Saini ◽

Vijayan Elimban ◽

Naranjan S. Dhalla

Keyword(s):

Superoxide Dismutase ◽

Sarcoplasmic Reticulum ◽

Cardiac Function ◽

Diastolic Pressure ◽

Ischemia Reperfusion ◽

Cardiac Performance ◽

Sr Protein ◽

Release Channel ◽

Beneficial Effects ◽

Rat Hearts

To study the cardioprotective effects of vanadate on ischemia-reperfusion (I/R) injury, isolated rat hearts perfused at constant flow were subjected to global ischemia for 30 min followed by reperfusion for 30 min. In this experimental model, I/R markedly decreased ventricular developed pressure and increased end-diastolic pressure. Pretreatment of hearts with 4 μM vanadate attenuated I/R-induced cardiac dysfunction. The reduction in sarcoplasmic reticulum (SR) Ca2+ uptake and Ca2+ release, as well as SR protein contents for Ca2+-pump ATPase and Ca2+-release channel, was also prevented by vanadate. Pretreatment of hearts with an antioxidant mixture containing superoxide dismutase + catalase exerted effects similar to those of vanadate in I/R hearts. Postischemic treatment of hearts with vanadate or superoxide dismutase + catalase also had beneficial effects on I/R-induced changes in cardiac performance and SR function. Alterations in cardiac function and SR Ca2+ transport due to an oxyradical-generating system (xanthine + xanthine oxidase) or an oxidant (H2O2) were attenuated by treatment with vanadate. These results suggest that vanadate may exert beneficial effects on cardiac performance and SR function in I/R hearts because of its antioxidant action.

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Respiratory pump maintains cardiac stroke volume during hypovolemia in young, healthy volunteers

Journal of Applied Physiology ◽

10.1152/japplphysiol.01009.2017 ◽

2018 ◽

Vol 124 (5) ◽

pp. 1319-1325 ◽

Cited By ~ 9

Author(s):

Maria Skytioti ◽

Signe Søvik ◽

Maja Elstad

Keyword(s):

Cardiac Output ◽

Stroke Volume ◽

Healthy Volunteers ◽

Negative Pressure ◽

Spontaneous Breathing ◽

Positive Pressure Ventilation ◽

Control Mode ◽

Positive Pressure ◽

Beneficial Effects ◽

Cardiac Stroke Volume

Spontaneous breathing has beneficial effects on the circulation, since negative intrathoracic pressure enhances venous return and increases cardiac stroke volume. We quantified the contribution of the respiratory pump to preserve stroke volume during hypovolemia in awake, young, healthy subjects. Noninvasive stroke volume, cardiac output, heart rate, and mean arterial pressure (Finometer) were recorded in 31 volunteers (19 women), 19–30 yr old, during normovolemia and hypovolemia (approximating 450- to 500-ml reduction in central blood volume) induced by lower-body negative pressure. Control-mode noninvasive positive-pressure ventilation was employed to reduce the effect of the respiratory pump. The ventilator settings were matched to each subject’s spontaneous respiratory pattern. Stroke volume estimates during positive-pressure ventilation and spontaneous breathing were compared with Wilcoxon matched-pairs signed-rank test. Values are overall medians. During normovolemia, positive-pressure ventilation did not affect stroke volume or cardiac output. Hypovolemia resulted in an 18% decrease in stroke volume and a 9% decrease in cardiac output ( P < 0.001). Employing positive-pressure ventilation during hypovolemia decreased stroke volume further by 8% ( P < 0.001). Overall, hypovolemia and positive-pressure ventilation resulted in a reduction of 26% in stroke volume ( P < 0.001) and 13% in cardiac output ( P < 0.001) compared with baseline. Compared with the situation with control-mode positive-pressure ventilation, spontaneous breathing attenuated the reduction in stroke volume induced by moderate hypovolemia by 30% (i.e., −26 vs. −18%). In the patient who is critically ill with hypovolemia or uncontrolled hemorrhage, spontaneous breathing may contribute to hemodynamic stability, whereas controlled positive-pressure ventilation may result in circulatory decompensation. NEW & NOTEWORTHY Maintaining spontaneous respiration has beneficial effects on hemodynamic compensation, which is clinically relevant for patients in intensive care. We have quantified the contribution of the respiratory pump to cardiac stroke volume and cardiac output in healthy volunteers during normovolemia and central hypovolemia. The positive hemodynamic effect of the respiratory pump was abolished by noninvasive, low-level positive-pressure ventilation. Compared with control-mode positive-pressure ventilation, spontaneous negative-pressure ventilation attenuated the fall in stroke volume by 30%.

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