scholarly journals Coronary blood flow influences tolerance to environmental extremes in fish

2021 ◽  
pp. jeb.239970
Author(s):  
Daniel Morgenroth ◽  
Tristan McArley ◽  
Albin Gräns ◽  
Michael Axelsson ◽  
Erik Sandblom ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Coronary Blood Flow ◽  
Heat Tolerance ◽  
Acute Hypoxia ◽  
Hypoxia Tolerance ◽  
Coronary Perfusion ◽  
Coronary Ligation ◽  
Environmental Extremes

Approximately half of all fishes have, in addition to the luminal venous O2 supply, a coronary circulation supplying the heart with fully oxygenated blood. Yet, it is not fully understood how coronary O2 delivery affects tolerance to environmental extremes such as warming and hypoxia. Hypoxia reduces arterial oxygenation, while warming increases overall tissue O2 demand. Thus, as both stressors are associated with reduced venous O2 supply to the heart, we hypothesised that coronary flow benefits hypoxia and warming tolerance. To test this hypothesis, we blocked coronary blood flow (via surgical coronary ligation) in rainbow trout (Oncorhynchus mykiss), and assessed how in vivo cardiorespiratory performance and whole-animal tolerance to acute hypoxia and warming was affected. While coronary ligation reduced routine stroke volume relative to trout with intact coronaries, cardiac output was maintained by increases in heart rate. However, in hypoxia, coronary ligated trout were unable to increase stroke volume to maintain cardiac output when bradycardia developed, which was associated with a slightly reduced hypoxia tolerance. Moreover, during acute warming coronary ligation caused cardiac function to collapse at lower temperatures, and reduced overall heat tolerance relative to trout with intact coronaries. We also found a positive relationship between individual hypoxia and heat tolerance across treatment groups, and tolerance to both environmental stressors was positively correlated with cardiac performance. Collectively, our findings show that coronary perfusion improves cardiac O2 supply, and therefore, cardiovascular function at environmental extremes, which benefits tolerance to natural and anthropogenically induced environmental perturbations.

Standard CPR versus interposed abdominal compression CPR in shunted single ventricle patients: comparison using a lumped parameter mathematical model

2021 ◽  
pp. 1-7
Author(s):  
Daniel Stromberg ◽  
Karen Carvalho ◽  
Alison Marsden ◽  
Carlos M. Mery ◽  
Camille Immanuel ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Cardiac Output ◽  
Coronary Blood Flow ◽  
Pulmonary Blood Flow ◽  
Single Ventricle ◽  
Perfusion Pressure ◽  
Coronary Perfusion Pressure ◽  
Coronary Perfusion ◽  
Lumped Parameter

Abstract Introduction: Cardiopulmonary resuscitation (CPR) in the shunted single-ventricle population is associated with poor outcomes. Interposed abdominal compression-cardiopulmonary resuscitation, or IAC-CPR, is an adjunct to standard CPR in which pressure is applied to the abdomen during the recoil phase of chest compressions. Methods: A lumped parameter model that represents heart chambers and blood vessels as resistors and capacitors was used to simulate blood flow in both Blalock-Taussig-Thomas and Sano circulations. For standard CPR, a prescribed external pressure waveform was applied to the heart chambers and great vessels to simulate chest compressions. IAC-CPR was modelled by adding phasic compression pressure to the abdominal aorta. Differential equations for the model were solved by a Runge-Kutta method. Results: In the Blalock-Taussig-Thomas model, mean pulmonary blood flow during IAC-CPR was 30% higher than during standard CPR; cardiac output increased 21%, diastolic blood pressure 16%, systolic blood pressure 8%, coronary perfusion pressure 17%, and coronary blood flow 17%. In the Sano model, pulmonary blood flow during IAC-CPR increased 150%, whereas cardiac output was improved by 13%, diastolic blood pressure 18%, systolic blood pressure 8%, coronary perfusion pressure 15%, and coronary blood flow 14%. Conclusions: In this model, IAC-CPR confers significant advantage over standard CPR with respect to pulmonary blood flow, cardiac output, blood pressure, coronary perfusion pressure, and coronary blood flow. These results support the notion that single-ventricle paediatric patients may benefit from adjunctive resuscitation techniques, and underscores the need for an in-vivo trial of IAC-CPR in children.

Contribution of extravascular compression to reduction of maximal coronary blood flow

1992 ◽  
Vol 262 (1) ◽  
pp. H68-H77
Author(s):  
F. L. Abel ◽  
R. R. Zhao ◽  
R. F. Bond
Keyword(s):  
Blood Flow ◽  
Coronary Blood Flow ◽  
Coronary Flow ◽  
Perfusion Pressure ◽  
Left Ventricular Pressure ◽  
Coronary Perfusion Pressure ◽  
Left Ventricular ◽  
Ventricular Pressure ◽  
Coronary Perfusion ◽  
Storage Site

Effects of ventricular compression on maximally dilated left circumflex coronary blood flow were investigated in seven mongrel dogs under pentobarbital anesthesia. The left circumflex artery was perfused with the animals' own blood at a constant pressure (63 mmHg) while left ventricular pressure was experimentally altered. Adenosine was infused to produce maximal vasodilation, verified by the hyperemic response to coronary occlusion. Alterations of peak left ventricular pressure from 50 to 250 mmHg resulted in a linear decrease in total circumflex flow of 1.10 ml.min-1 x 100 g heart wt-1 for each 10 mmHg of peak ventricular to coronary perfusion pressure gradient; a 2.6% decrease from control levels. Similar slopes were obtained for systolic and diastolic flows as for total mean flow, implying equal compressive forces in systole as in diastole. Increases in left ventricular end-diastolic pressure accounted for 29% of the flow changes associated with an increase in peak ventricular pressure. Doubling circumferential wall tension had a minimal effect on total circumflex flow. When the slopes were extrapolated to zero, assuming linearity, a peak left ventricular pressure of 385 mmHg greater than coronary perfusion pressure would be required to reduce coronary flow to zero. The experiments were repeated in five additional animals but at different perfusion pressures from 40 to 160 mmHg. Higher perfusion pressures gave similar results but with even less effect of ventricular pressure on coronary flow or coronary conductance. These results argue for an active storage site for systolic arterial flow in the dilated coronary system.

Cardiac Output Changes in Newborns With Hyperbilirubinemia Treated With Phototherapy

PEDIATRICS ◽  
1985 ◽  
Vol 76 (6) ◽  
pp. 918-921
Author(s):  
Frans J. Walther ◽  
Paul Y. K. Wu ◽  
Bijan Siassi
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Skin Blood Flow ◽  
Peripheral Blood ◽  
Cardiovascular Effects ◽  
Tissue Perfusion ◽  
Peripheral Blood Flow ◽  
Limb Blood Flow ◽  
Term Infants

Phototherapy is known to increase peripheral blood flow in neonates, but information on the associated cardiovascular effects is not available. Using pulsed Doppler echocardiography we evaluated cardiac output and stroke volume in 12 preterm and 13 term neonates during and after phototherapy. We concomitantly measured arterial limb blood flow by strain gauge plethysmography and skin blood flow by photoplethysmography. Cardiac output decreased by 6% due to reduced stroke volume during phototherapy, whereas total limb blood flow and skin blood flow increased by 38% and 41%, respectively. Peripheral blood flow increments tended to be higher in the preterm than in the term infants. The reduced stroke volume during phototherapy may be an expression of reduced activity of the newborn during phototherapy. For healthy neonates the reduction in cardiac output is minimal, but for sick infants with reduced cardiac output, this reduction may further aggravate the decrease in tissue perfusion.

scholarly journals Development of a Simple ImageJ-Based Method for Dynamic Blood Flow Tracking in Zebrafish Embryos and Its Application in Drug Toxicity Evaluation

Inventions ◽  
2019 ◽  
Vol 4 (4) ◽  
pp. 65 ◽  
Author(s):  
Fiorency Santoso ◽  
Bonifasius Putera Sampurna ◽  
Yu-Heng Lai ◽  
Sung-Tzu Liang ◽  
Erwei Hao ◽  
...  
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Cardiac Output ◽  
Blood Cell ◽  
Stroke Volume ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Video Recording ◽  
Cardiovascular Function ◽  
Zebrafish Embryos

This study aimed to develop a simple and cost-effective method to measure blood flow in zebrafish by using an image-based approach. Three days post fertilization (dpf) zebrafish embryos were mounted with methylcellulose and subjected to video recording for tracking blood flow under an inverted microscope equipped with a high-speed CCD camera. In addition, Hoffman lens was used to enhance the blood cell contrast. The red blood cell movement was tracked by using the TrackMate plug-in in the ImageJ image processing program. Moreover, Stack Difference and Time Series Analyzer plug-in were used to detect dynamic pixel changes over time to calculate the blood flow rate. In addition to blood flow velocity and heart rate, the effect of drug treatments on other cardiovascular function parameters, such as stroke volume and cardiac output remains to be explored. Therefore, by using this method, the potential side effects on the cardiovascular performance of ethyl 3-aminobenzoate methanesulfonate (MS222) and 3-isobutyl-1-methylxanthine (IBMX) were evaluated. MS222 is a common anesthetic, while IBMX is a naturally occurring methylxanthine. Compared to normal embryos, MS222- and IBMX-treated embryos had a reduced blood flow velocity by approximately 72% and 58%, respectively. This study showed that MS222 significantly decreased the heart rate, whereas IBMX increased the heart rate. Moreover, it also demonstrated that MS222 treatment reduced 50% of the stroke volume and cardiac output. While IBMX decreased the stroke volume only. The results are in line with previous studies that used expensive instruments and complicated software analysis to assess cardiovascular function. In conclusion, a simple and low-cost method can be used to study blood flow in zebrafish embryos for compound screening. Furthermore, it could provide a precise measurement of clinically relevant cardiac functions, specifically heart rate, stroke volume, and cardiac output.

Coronary hyperperfusion and myocardial metabolism in isolated and intact hearts

1987 ◽  
Vol 253 (5) ◽  
pp. H1271-H1278 ◽  
Author(s):  
W. P. Miller ◽  
N. Shimamoto ◽  
S. H. Nellis ◽  
A. J. Liedtke
Keyword(s):  
Blood Flow ◽  
Fatty Acid ◽  
Coronary Blood Flow ◽  
Myocardial Metabolism ◽  
Left Ventricular ◽  
Coronary Perfusion ◽  
Rat Hearts ◽  
Heart Preparation ◽  
Significant Change ◽  
Lv Volume

We determined the independent influence of coronary hyperperfusion on myocardial metabolism in isolated and intact hearts. In an isovolumic blood-perfused rat heart preparation working against a left ventricular (LV) balloon, the effect of increasing coronary perfusion pressure from 100 to 150 mmHg was assessed. In three groups of rat hearts LV volume was fixed to obtain LV peak pressures of 42 +/- 3, 101 +/- 5, and 130 +/- 6 mmHg. With coronary hyperperfusion, LV pressure increased 27, 18, and 16%, LV maximum time derivative of pressure (dP/dt) increased 39, 20, and 22%, and myocardial O2 consumption (VO2) increased 16, 17, and 33%, respectively. In a fourth group, LV peak pressure was held constant at 92 +/- 4 mmHg during coronary hyperperfusion by decreasing LV volume. In this group, despite an increase in coronary blood flow of 48%, there was no significant difference in LV maximum dP/dt or myocardial VO2. Thus, in isolated rat hearts, coronary hyperperfusion was not an independent stimulus to myocardial VO2. To further test this, the effect of coronary hyperperfusion on myocardial metabolism was studied in an intact working swine heart preparation where the cardiac output was fixed with a right heart bypass circuit. Fatty acid oxidation in the left anterior descending bed was assessed by production of 14CO2 from [14C(U)]palmitate. A comparison of coronary perfusion 106 +/- 5 vs. 197 +/- 5 mmHg resulted in no significant change in global LV function, including LV internal diameter. Despite a 70% increase in coronary blood flow, there was no significant change in myocardial VO2 or fatty acid utilization.(ABSTRACT TRUNCATED AT 250 WORDS)

A simple module for on-line computation of stroke volume and cardiac output

1975 ◽  
Vol 38 (5) ◽  
pp. 927-929 ◽  
Author(s):  
G. Pinardi ◽  
A. Sainz ◽  
E. Santiago
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Data Analysis ◽  
Stroke Volume ◽  
Simple Module ◽  
Cardiovascular Responses ◽  
Aortic Blood Flow ◽  
Aortic Blood ◽  
On Line ◽  
Aortic Blood Flow Velocity

An easily constructed, low-priced, simple, and reliable module to obtain stroke volume and cardiac output by analog integration of aortic blood flow velocity signals is described. Rapid data analysis of physiologic and pharmacologic cardiovascular responses in dogs is greatly facilitated by on line computation of these parameters.

Alpha 2-adrenoceptor stimulation can augment coronary vasodilation maximally induced by adenosine in dogs

1989 ◽  
Vol 257 (1) ◽  
pp. H132-H140 ◽  
Author(s):  
M. Hori ◽  
M. Kitakaze ◽  
J. Tamai ◽  
K. Iwakura ◽  
A. Kitabatake ◽  
...  
Keyword(s):  
Blood Flow ◽  
Coronary Blood Flow ◽  
Small Dose ◽  
Reactive Hyperemia ◽  
Coronary Perfusion Pressure ◽  
Coronary Perfusion ◽  
Coronary Vasodilation ◽  
Beta Adrenoceptor ◽  
Adenosine Concentration ◽  
Hyperemic Flow

To determine whether alpha 2-adrenoceptor stimulation can augment adenosine-induced coronary vasodilation, 34 open-chest dogs were studied. When a small dose of clonidine (up to 0.24 micrograms.kg-1.min-1 ic) was administered under beta-adrenoceptor blockade, coronary blood flow [312 +/- 16 (SE) ml.100 g-1.min-1] maximally induced by intracoronary infusion of adenosine was further increased (P less than 0.05) by 66 +/- 16 ml.100 g-1.min-1, despite no significant changes in coronary perfusion pressure, myocardial oxygen consumption, and coronary venous adenosine concentration. However, when a larger dose of clonidine (0.36–0.60 micrograms.kg-1.min-1) was infused, adenosine-induced flow progressively decreased. This biphasic action of the alpha 2-adrenoceptor activity was also observed when the dose of norepinephrine was increased during alpha 1-adrenoceptor blockade with prazosin. Norepinephrine up to 0.24 micrograms.kg-1.min-1 (ic) further increased adenosine-induced coronary blood flow by 24 +/- 5% (P less than 0.001), whereas hyperemic flow was decreased by a larger dose of norepinephrine. In contrast to the alpha 2-adrenoceptor stimulation, the alpha 1-adrenoceptor stimulation (norepinephrine with yohimbine) progressively decreased coronary blood flow. Furthermore, with a small dose of clonidine, reactive hyperemic flow significantly increased compared with that without clonidine (303 +/- 13 vs. 355 +/- 13 ml.100 g-1.min-1, P less than 0.001), but a larger dose of clonidine adversely reduced reactive flow (254 +/- 18 ml.100 g-1.min-1, P less than 0.001). Adenosine release during reactive hyperemia with and without intracoronary infusions of clonidine were not altered significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

Regional blood flow and cardiac output during acute hypoxia in the anesthetized dog

1963 ◽  
Vol 204 (6) ◽  
pp. 963-968 ◽  
Author(s):  
John F. Murray ◽  
I. Maureen Young
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Regional Blood Flow ◽  
Acute Hypoxia ◽  
Arterial Oxygen Saturation ◽  
Head Kidney ◽  
Arterial Oxygen ◽  
Circulatory Effects ◽  
Low Concentrations ◽  
Anesthetized Dogs

The circulatory effects of breathing low concentrations of oxygen were studied in ten anesthetized dogs. Simultaneous measurements were made of cardiac output (indicator dilution technique) and blood flow to the head, kidney, and hind limb (electromagnetic flowmeters). Four experiments were performed with the addition of succinylcholine to inhibit the ventilatory response to hypoxia and maintain pCO2 constant. A rise in cardiac output and mean arterial pressure occurred which was significantly correlated to the decrease in arterial oxygen saturation. No threshold for these responses was found. Blood flow tended to increase during hypoxia in the regions studied but the responses were variable and only the change in renal blood flow had a significant correlation to arterial oxygen unsaturation. Systemic and regional vascular resistances during hypoxia varied both in direction and magnitude of change. The preponderant effects of hypoxia influence cardiac output more than peripheral vascular resistance.

Effects of khellin on coronary blood flow and related metabolic functions

1959 ◽  
Vol 196 (2) ◽  
pp. 391-393 ◽  
Author(s):  
Richard L. Farrand ◽  
Steven M. Horvath
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Coronary Blood Flow ◽  
Control Period ◽  
Systemic Arterial Pressure ◽  
Arterial Oxygen ◽  
Arterial Oxygen Content ◽  
Fick Principle ◽  
Metabolic Functions ◽  
Pulmonary Arterial

Khellin, a drug employed as a coronary dilator, was tested to determine its effects on the cardiovascular system of the dog. Ten mongrel dogs were anesthetized with Nembutal and, after control observations were made, given an intravenous administration of 1 mg/kg body weight of khellin. Coronary blood flow and cardiac output samples were drawn during the control period and at 10, 40 and 80 minutes after administration of the drug Cardiac output was calculated by the direct Fick principle and coronary blood flow by the nitrous oxide method. There was a significant (5%) increase in the arterial oxygen content during the 10- and 40-minute intervals, but no change was observed at 80 minutes. An increase in arterial-mixed venous oxygen difference occurred at 40 and 80 minutes. No change in systemic arterial pressure or cardiac output was noted at any time. Coronary blood flow had decreased slightly at 80 minutes. A significant decrease in carbon dioxide content of the arterial, pulmonary arterial and coronary sinus blood was observed, possibly as a consequence of hyperventilation. Khellin appeared to alter the metabolism of the myocardial and splanchnic tissues.

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