Cardiovascular adaptation of newborn lambs to hypervolemia with polycythemia

1970 ◽  
Vol 48 (5) ◽  
pp. 312-320 ◽  
Author(s):  
Jean-Claude Fouron ◽  
Francine Hébert
Keyword(s):  
Blood Volume ◽  
Ductus Arteriosus ◽  
Right Atrial ◽  
Control Group ◽  
Base Line ◽  
Progressive Reduction ◽  
Fick Principle ◽  
Acute Increase ◽  
Left And Right ◽  
Line Level

Hemodynamic studies were carried out in five newborn lambs before, during, and for a period of 3 h after an increase of approximately 50% in blood volume. Four other animals served as a control group. The animals were delivered by cesarean less than 1 week before the anticipated date of birth. Pressures were continuously recorded in aorta, pulmonary artery, and right and left atrium. Pulmonary and systemic flows as well as the possible shunts through the ductus arteriosus and the foramen ovale were calculated according to the Fick principle. The results showed a marked increase in systemic flows, followed by a progressive reduction but no return to the base-line level, closure of the ductus arteriosus during or shortly after the infusion, and a transient systemic and pulmonary hypertension associated with a marked elevation in left and right atrial pressures. No change was observed in the cardiac rhythm or the O2 consumption. These data suggest that the venous vascular bed of newborn lambs is less able than that of adult animals to cope with an acute increase in blood volume.

Prenatal ultrasound diagnosis of pulmonary atresia in combination with left atrial isomerism

2017 ◽  
Author(s):  
M Medvedev, M.V. Kubrina, O.S. Zarubina et all
Keyword(s):  
Left Atrial ◽  
Reverse Flow ◽  
Ductus Arteriosus ◽  
Pulmonary Atresia ◽  
Prenatal Ultrasound ◽  
Ultrasound Diagnosis ◽  
Right Atrial ◽  
Second Trimester ◽  
Left And Right ◽  
Atrial Isomerism

Two cases of prenatal ultrasound diagnosis of left atrial isomerism in the second trimester of gestation is presented. These two cases were in combination with pulmonary atresia and right aortic arch. Left atrial isomerism was identify by the digit-like shape of the left and right atrial appendages. The pulmonary atresia was identified on the basis of reverse flow in small pulmonary artery. A right aortic was identified by “U”-shaped confluence of aorta and ductus arteriosus in view of three vessels and trachea. The trachea was located between the vessels. The pregnancies were terminated and prenatal diagnosis was conformed at autopsy

Prediction of circulatory equilibrium in response to changes in stressed blood volume

2005 ◽  
Vol 289 (1) ◽  
pp. H301-H307 ◽  
Author(s):  
Kazunori Uemura ◽  
Toru Kawada ◽  
Atsunori Kamiya ◽  
Takeshi Aiba ◽  
Ichiro Hidaka ◽  
...  
Keyword(s):  
Blood Volume ◽  
Single Point ◽  
Point Estimation ◽  
Accurate Prediction ◽  
Atrial Pressure ◽  
Right Atrial ◽  
Right Heart ◽  
Left And Right ◽  
Failure Conditions ◽  
The Right

Accurate prediction of cardiac output (CO), left atrial pressure (PLA), and right atrial pressure (PRA) is a prerequisite for management of patients with compromised hemodynamics. In our previous study (Uemura et al. Am J Physiol Heart Circ Physiol 286: H2376–H2385, 2004), we demonstrated a circulatory equilibrium framework, which permits the prediction of CO, PLA, and PRA once the venous return surface and integrated CO curve are known. Inasmuch as we also showed that the surface can be estimated from single-point CO, PLA, and PRA measurements, we hypothesized that a similar single-point estimation of the CO curve would enable us to predict hemodynamics. In seven dogs, we measured the PLA-CO and PRA-CO relations and derived a standardized CO curve using the logarithmic function CO = SL[ln(PLA − 2.03) + 0.80] for the left heart and CO = SR[ln(PRA − 2.13) + 1.90] for the right heart, where SL and SR represent the preload sensitivity of CO, i.e., pumping ability, of the left and right heart, respectively. To estimate the integrated CO curve in each animal, we calculated SL and SR from single-point CO, PLA, and PRA measurements. Estimated and measured CO agreed reasonably well. In another eight dogs, we altered stressed blood volume (−8 to +8 ml/kg of reference volume) under normal and heart failure conditions and predicted the hemodynamics by intersecting the surface and the CO curve thus estimated. We could predict CO [ y = 0.93 x + 6.5, r 2 = 0.96, standard error of estimate (SEE) = 7.5 ml·min−1·kg−1], PLA ( y = 0.90 x + 0.5, r 2 = 0.93, SEE = 1.4 mmHg), and PRA ( y = 0.87 x + 0.4, r 2 = 0.91, SEE = 0.4 mmHg) reasonably well. In conclusion, single-point estimation of the integrated CO curve enables accurate prediction of hemodynamics in response to extensive changes in stressed blood volume.

Right atrial volume during hemorrhage in the dog

1986 ◽  
Vol 250 (6) ◽  
pp. H1136-H1144 ◽  
Author(s):  
D. E. Carlson ◽  
K. W. Burchard ◽  
D. S. Gann
Keyword(s):  
Blood Volume ◽  
Femoral Vein ◽  
Ventricular Volume ◽  
Rate Of Change ◽  
Right Atrial ◽  
Base Line ◽  
Atrial Volume ◽  
Ventricular Systole ◽  
Absolute Volume ◽  
Alpha Chloralose

Atrial B receptors elicit reflex changes after hemorrhage and respond to changes in atrial volume, but the latter have not been measured after hemorrhage. An impedance catheter that was originally designed to measure ventricular volume was advanced into the atrium from the femoral vein in each of 10 splenectomized dogs that were anesthetized with alpha-chloralose. The rate of hemorrhage and reinfusion was 2% of the estimated blood volume per min. Cardiac output (CO) was measured with dye dilution. The components of the atrial volume signal that were most sensitive to hemorrhage were the filling that occurred during late ventricular systole (Vs) and the absolute volume at the end of ventricular systole, (Vabs). Both variables were significantly less than base line (P less than 0.05) after 10% hemorrhage. The rate of change of Vs decreased significantly after 20% hemorrhage. However, the volume ejected with each atrial beat (Ve) decreased significantly (P less than 0.05) only after 30% hemorrhage. Atrial output (AO) as computed by multiplying Ve by heart rate (HR) did not change after hemorrhage. The ratio of AO to CO increased in direct proportion to HR (P less than 0.01) so that after 30% hemorrhage, for which HR was high, the decreases in CO from base line in individual dogs correlated significantly with the changes in AO (P less than 0.01). Since the B receptors are known to fire at the end of the ventricular systole at a rate that is dependent on blood volume, their firing may be a function of the concomitant atrial signals, Vs and Vabs, that are most sensitive to blood volume, and these atrial signals may serve as indexes of B fiber activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Transmural metabolic gradients in the normal dog left ventricle: effect of right atrial pacing

1977 ◽  
Vol 233 (2) ◽  
pp. H217-H221 ◽  
Author(s):  
T. B. Allison ◽  
J. W. Holsinger
Keyword(s):  
Right Atrial ◽  
Control Group ◽  
Base Line ◽  
Atrial Pacing ◽  
Stroke Work ◽  
Ischemic Insult ◽  
Circumflex Artery ◽  
Heart Work ◽  
Anesthetized Dogs ◽  
The Right

The effects of atrial pacing on tissue metabolite levels known to be sensitive to ischemia were examined. Anesthetized dogs were thoracotomized and a pacing electrode was sutured to the right atrium. Pacing at rates of 200 or 250 beats/min (10 animals per group) was performed for 15 min after base-line hemodynamic data had been obtained. At the end of the pacing period, a transmural biopsy was taken, frozen in liquid nitrogen, and sectioned into subepicardial, midmyocardial, and subendocardial layers. ATP, phosphocreatine, lactate, and glycogen were extracted and analyzed. Significant (P less than 0.001) transmural gradients of each of these metabolites existed in the control group. Pacing had no significant (P greater than 0.2) effect on any metabolite from layer to layer at 200 or 250 beats/min. However, indices of heart work (i.e., contractility (dP/dt), stroke work, and stroke volume) demonstrated significant reductions (P less than 0.01) due to pacing, while circumflex artery blood flow increased more than twofold (P less than 0.001) at the highest rate. These data suggest that physiologic autoregulation occurred during pacing and protected the subendocardium from stress-induced ischemic insult.

scholarly journals The Effect of Moderate Changes in Blood Volume on Left and Right Atrial Pressures

1956 ◽  
Vol 4 (1) ◽  
pp. 91-94 ◽  
Author(s):  
JAMES P. HENRY ◽  
OTTO H. GAUER ◽  
HERBERT O. SIEKER
Keyword(s):  
Blood Volume ◽  
Right Atrial ◽  
Left And Right

Resistance and volume changes caused by nitroprusside in the dog

1979 ◽  
Vol 237 (1) ◽  
pp. H99-H103 ◽  
Author(s):  
S. A. Rubin ◽  
G. Misbach ◽  
J. Lekven ◽  
W. W. Parmley ◽  
J. V. Tyberg
Keyword(s):  
Vascular Resistance ◽  
Right Atrial ◽  
Control Group ◽  
Base Line ◽  
Volume Changes ◽  
Pharmacologic Agent ◽  
Vascular Volume ◽  
Successive Level ◽  
Similar Decrease ◽  
Nitroprusside Infusion

Changes in vascular volume caused by a pharmacologic agent are frequently inferred rather than directly measured. We investigated the effects of nitroprusside in 8 dogs divided into 2 groups: control and splenectomized. We anesthetized the dogs using pentobarbital, and surgically prepared a veno-right atrial bypass preparation whose controlled cardiac output and external reservoir allowed measurement of both changes in vascular resistance and changes in vascular volume. In both groups, blood pressure (mean +/- SD) decreased at each successive level of nitroprusside: 114 +/- 24 mmHg (base line), 101 +/- 19 mmHg (45 microgram/min), 90 +/- 16 mmHg (90 microgram/min), 81 +/- 17 mmHg (180 microgram/min), 68 +/- 18 mmHg (360 microgram/min). Nitroprusside caused a large and similar decrease in vascular resistance in both groups. In the control group, vascular volume increased above base line 5.5 +/- 2.7, 8.3 +/- 3.2, 11.6 +/- 2.9, and 14.7 +/- 3.5 ml/kg at each successive level of nitroprusside infusion, whereas in the splenectomized group vascular volume increased above base line 0.9 +/- 0.3, 2.5 +/- 1.0, 3.3 +/- 1.1, and 4.0 +/- 1.3 ml/kg at each successive level of nitroprusside infusion, but increased significantly less than the control group. We concluded that nitroprusside decreases vascular resistance and increases vascular volume and that the spleen is the major site of changes in vascular volume caused by nitroprusside.

Melatonin Improves Erythropoietin Hyporesponsiveness via Suppression of Inflammation

2019 ◽  
Vol 14 (3) ◽  
pp. 203-208
Author(s):  
Evan Noori Hameed ◽  
Haydar F. Hadi AL Tukmagi ◽  
Hayder Ch Assad Allami
Keyword(s):  
Iron Status ◽  
Transferrin Saturation ◽  
Control Group ◽  
Base Line ◽  
Inadequate Response ◽  
Inflammatory Parameters ◽  
Tnf Α ◽  
Before And After ◽  
And Control ◽  
Controlled Clinical Study

Background: Inadequate response to Erythropoietin Stimulating Agents (ESA) despite using relatively larger doses regimen represents a potential risk factor of Cardiovascular (CV) related mortality in addition to health-care economic problems in anemic patients with Chronic Kidney Disease (CKD). Erythropoietin (EPO) hyporesponsiveness related to inflammation has been increased progressively. Melatonin is well known as a potent anti-inflammatory agent. Therefore, the current study was designed to evaluate whether melatonin could improve anemic patients response to EPO. Methods: This single controlled clinical study was carried out in 41 CKD patients with hemoglobin (Hb) levels less than 11g/dl divided randomly in a 1:1 ratio into 2 groups; treatment group who received 5mg melatonin plus their regular treatments and control group who received their regular treatments only. Hematological and iron status parameters include Hb level, serum iron (S. iron), Transferrin Saturation Ratio (TSAT) and serum ferritin (S. ferritin) in addition to inflammatory parameters that include tissue necrotic factor alfa (TNF-α), interleukin-1beta (IL-1β) and interleukin-6 (IL-6) determined before and after 12 weeks of treatment. Results: Melatonin remarkably increases the Hb level with a significant increase in S. iron and TSAT compared to baseline. The elevation of S. iron and TSAT was significantly higher in the melatonin group. Additionally, all inflammatory markers estimated were reduced significantly by melatonin compared to base line and control group. Conclusion: The results of the current study showed that melatonin has an advantageous effect on improving EPO response in anemic patients with CKD.

scholarly journals Inducibility, but not stability, of atrial fibrillation is increased by NOX2 overexpression in mice

2021 ◽  
Author(s):  
Alexandra S Mighiu ◽  
Alice Recalde ◽  
Klemen Ziberna ◽  
Ricardo Carnicer ◽  
Jakub Tomek ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Superoxide Production ◽  
Right Atrial ◽  
Burst Stimulation ◽  
Lv Mass ◽  
Surface Ecg ◽  
Tissue Homogenates ◽  
Genotype Difference ◽  
Left And Right

Abstract Aims Gp91-containing NADPH oxidases (NOX2) are a significant source of myocardial superoxide production. An increase in NOX2 activity accompanies atrial fibrillation (AF) induction and electrical remodelling in animal models and predicts incident AF in humans; however, a direct causal role for NOX2 in AF has not been demonstrated. Accordingly, we investigated whether myocardial NOX2 overexpression in mice (NOX2-Tg) is sufficient to generate a favourable substrate for AF and further assessed the effects of atorvastatin, an inhibitor of NOX2, on atrial superoxide production and AF susceptibility. Methods and results NOX2-Tg mice showed a 2- to 2.5-fold higher atrial protein content of NOX2 compared with wild-type (WT) controls, which was associated with a significant (twofold) increase in NADPH-stimulated superoxide production (2-hydroxyethidium by HPLC) in left and right atrial tissue homogenates (P = 0.004 and P = 0.019, respectively). AF susceptibility assessed in vivo by transoesophageal atrial burst stimulation was modestly increased in NOX2-Tg compared with WT (probability of AF induction: 88% vs. 69%, respectively; P = 0.037), in the absence of significant alterations in AF duration, surface ECG parameters, and LV mass or function. Mechanistic studies did not support a role for NOX2 in promoting electrical or structural remodelling, as high-resolution optical mapping of atrial tissues showed no differences in action potential duration and conduction velocity between genotypes. In addition, we did not observe any genotype difference in markers of fibrosis and inflammation, including atrial collagen content and Col1a1, Il-1β, Il-6, and Mcp-1 mRNA. Similarly, NOX2 overexpression did not have consistent effects on RyR2 Ca2+ leak nor did it affect PKA or CaMKII-mediated RyR2 phosphorylation. Finally, treatment with atorvastatin significantly inhibited atrial superoxide production in NOX2-Tg but had no effect on AF induction in either genotype. Conclusion Together, these data indicate that while atrial NOX2 overexpression may contribute to atrial arrhythmogenesis, NOX2-derived superoxide production does not affect the electrical and structural properties of the atrial myocardium.

scholarly journals P946 Right atrial volumetric and functional analysis by three-dimensional speckle-tracking echocardiography in acromegaly

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
A Kormanyos ◽  
A Kalapos ◽  
P Domsik ◽  
N Gyenes ◽  
N Ambrus ◽  
...  
Keyword(s):  
Speckle Tracking ◽  
Speckle Tracking Echocardiography ◽  
Three Dimensional ◽  
Radial Strain ◽  
Human Growth ◽  
Active Phase ◽  
Right Atrial ◽  
Control Group ◽  
Cardiovascular Comorbidities ◽  
Atrial Contraction

Abstract Introduction Acromegaly is a chronic, rare hormonal disease associated with major cardiovascular comorbidities. The disease, in the majority of the cases, is caused by a benign human growth hormone secreting adenoma. Cardiovascular involvement is especially common in acromegaly patients from the most common hypertension to cardiomyopathy. It was set out to quantify right atrial (RA) morphology and function in a group of acromegaly patients using three-dimensional (3D) speckle-tracking echocardiography (3DSTE). Methods The study comprised 30 patients from which 8 patients were excluded due to inadequate image quality. Mean age of the remaining acromegaly patients were 53.7 ± 14.5 years (7 males). Ten patients were in active phase, while 12 subjects had inactive acromegaly. In the control group 40 healthy adults were enrolled (mean age: 52.3 ± 8.2 years, 15 males). In each case, complete two-dimensional Doppler echocardiography was performed followed by 3DSTE. Results Maximum (54.5 ± 14.4 ml vs. 47.2 ± 11.6 ml, p <0.05) and minimum (35.5 ± 10.2 ml vs. 29.2 ± 9.1 ml, p <0.05) RA volumes and RA volume before atrial contraction (45.1 ± 11.1 ml vs. 38.2 ± 10.3 ml, p <0.05) were significantly higher in case of acromegaly compared to the healthy controls. Both global and mean segmental peak 3D strain (-11.94 ± 7.52% vs. -8.07 ± 5.03%, p <0.05 and -17.16 ± 6.13% vs. -13.78 ± 5.35%, p <0.05) were higher in the acromegaly group compared to the controls. At atrial contraction, mean segmental radial strain (-13.22 ± 6.45% vs. -9.74 ± 4.58%, p <0.05) was significantly higher and mean segmental 3D strain (-9.78 ± 5.44% vs. -13.78 ± 5.35%, p <0.05) was significantly lower in the acromegaly group compared to the controls. Between the active and inactive group of acromegaly patients, mean segmental longitudinal strain (28.17 ± 4.89% vs. 35.34 ± 9.75%, p <0.05) was significantly different. Numerous independent strain parameters had significant correlations with different hormonal variables in the active acromegaly group. These correlations were not present in the inactive acromegaly subgroup. Conclusion Acromegaly is associated with significant RA volumetric and functional abnormalities.

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