scholarly journals Intrauterine endotoxin-induced impairs pulmonary vascular function and right ventricular performance in infant rats and improvement with early vitamin D therapy

2015 ◽  
Vol 309 (12) ◽  
pp. L1438-L1446 ◽  
Author(s):  
Erica Mandell ◽  
Kyle N. Powers ◽  
Julie W. Harral ◽  
Gregory J. Seedorf ◽  
Kendall S. Hunter ◽  
...  
Keyword(s):  
Vitamin D ◽  
Right Ventricular ◽  
Vascular Function ◽  
Late Gestation ◽  
Stroke Work ◽  
Mechanical Stiffness ◽  
Ventricular Performance ◽  
Ecm Remodeling ◽  
Collagen Iii ◽  
Fetal Rats

High pulmonary vascular resistance (PVR), proximal pulmonary artery (PA) impedance, and right ventricular (RV) afterload due to remodeling contribute to the pathogenesis and severity of pulmonary hypertension (PH). Intra-amniotic exposure to endotoxin (ETX) causes sustained PH and high mortality in rat pups at birth, which are associated with impaired vascular growth and RV hypertrophy in survivors. Treatment of ETX-exposed pups with antenatal vitamin D (vit D) improves survival and lung growth, but the effects of ETX exposure on RV-PA coupling in the neonatal lung are unknown. We hypothesized that intrauterine ETX impairs RV-PA coupling through sustained abnormalities of PA stiffening and RV performance that are attenuated with vit D therapy. Fetal rats were exposed to intra-amniotic injections of ETX, ETX+vit D, or saline at 20 days gestation (term = 22 days). At postnatal day 14, pups had pressure-volume measurements of the RV and isolated proximal PA, respectively. Lung homogenates were assayed for extracellular matrix (ECM) composition by Western blot. We found that ETX lungs contain decreased α-elastin, lysyl oxidase, collagen I, and collagen III proteins ( P < 0.05) compared control and ETX+vit D lungs. ETX-exposed animals have increased RV mechanical stroke work ( P < 0.05 vs. control and ETX+vit D) and elastic potential energy ( P < 0.05 vs. control and ETX+vit D). Mechanical stiffness and ECM remodeling are increased in the PA ( P < 0.05 vs. control and ETX+vit D). We conclude that intrauterine exposure of fetal rats to ETX during late gestation causes persistent impairment of RV-PA coupling throughout infancy that can be prevented with early vit D treatment.

scholarly journals Chronic intrauterine pulmonary hypertension increases main pulmonary artery stiffness and adventitial remodeling in fetal sheep

2014 ◽  
Vol 307 (11) ◽  
pp. L822-L828 ◽  
Author(s):  
R. Blair Dodson ◽  
Matthew R. Morgan ◽  
Csaba Galambos ◽  
Kendall S. Hunter ◽  
Steven H. Abman
Keyword(s):  
Pulmonary Hypertension ◽  
Main Pulmonary Artery ◽  
Pulmonary Arteries ◽  
Clinical Syndrome ◽  
Late Gestation ◽  
Biaxial Testing ◽  
Mechanical Stiffness ◽  
Sheep Model ◽  
Fetal Sheep ◽  
Ecm Remodeling

Persistent pulmonary hypertension of the newborn (PPHN) is a clinical syndrome that is characterized by high pulmonary vascular resistance due to changes in lung vascular growth, structure, and tone. PPHN has been primarily considered as a disease of the small pulmonary arteries (PA), but proximal vascular stiffness has been shown to be an important predictor of morbidity and mortality in other diseases associated with pulmonary hypertension (PH). The objective of this study is to characterize main PA (MPA) stiffness in experimental PPHN and to determine the relationship of altered biomechanics of the MPA with changes in extracellular matrix (ECM) content and orientation of collagen and elastin fibers. MPAs were isolated from control and PPHN fetal sheep model and were tested by planar biaxial testing to measure stiffness in circumferential and axial vessel orientations. Test specimens were fixed for histological assessments of the vascular wall ECM constituents collagen and elastin. MPAs from PPHN sheep had increased mechanical stiffness ( P < 0.05) and altered ECM remodeling compared with control MPA. A constitutive mathematical model and histology demonstrated that PPHN vessels have a smaller contribution of elastin and a greater role for collagen fiber engagement compared with the control arteries. We conclude that exposure to chronic hemodynamic stress in late-gestation fetal sheep increases proximal PA stiffness and alters ECM remodeling. We speculate that proximal PA stiffness further contributes to increased right ventricular impedance in experimental PPHN, which contributes to abnormal transition of the pulmonary circulation at birth.

Abstract 17264: Impaired Right Ventricular and Pulmonary Vascular Function in a Mouse Model of Sickle Cell Disease

Circulation ◽  
2018 ◽  
Vol 138 (Suppl_1) ◽  
Author(s):  
David A Schreier ◽  
Diana M Tabima ◽  
Jennifer L Philip ◽  
Timothy A Hacker ◽  
Naomi C Chesler
Keyword(s):  
Cardiac Output ◽  
Sickle Cell Disease ◽  
Right Ventricular ◽  
Sickle Cell ◽  
Vascular Function ◽  
Vena Cava ◽  
Stroke Work ◽  
Cell Disease ◽  
The Impact ◽  
Rv Function

Introduction: In sickle cell disease (SCD), red blood cell abnormalities contribute to pulmonary hypertension (PH) in adults and children. Right ventricular (RV) hypertrophy and dilatation are also associated with SCD, likely due to a combination of PH and coronary microvascular disease. The goal of this study was to use a comprehensive hemodynamic approach to quantify the impact of SCD on RV function, RV afterload, and cardiopulmonary reserve. Hypothesis: We hypothesized that mice with SCD would have poor RV function, increased RV afterload, and less cardiopulmonary reserve compared to mice without SCD. Methods: 22 male Berkeley SCD mice and 24 male C57Bl6 mice (CTL) aged 30-32 weeks old were used. Approximately half of each genotype were used for RV function and VVC measurements; RV pressure-volume (PV) loops were obtained at baseline and after a brief inferior vena cava occlusion in an open-chest procedure. In the rest, RV afterload was quantified from simultaneous pulmonary artery pressure and diameter measurements in a closed-chest procedure. All measurements were obtained under normoxic ventilation (21% oxygen) and, subsequently, after acutely hypoxic (AH) ventilation (10% oxygen) to assess cardiopulmonary reserve. Results: RV hypertrophy and increased RV systolic pressure confirmed PH in SCD mice (Figure A). Cardiac output, RV end-diastolic volume, and preload-recruitable stroke work (PRSW) were increased in SCD mice and RV compliance was decreased compared to controls. In response to AH, cardiac output dropped dramatically (Figure B), PRSW decreased, pulmonary vascular resistance increased and compliance decreased more in SCD mice than in CTL mice, indicating decreased cardiopulmonary reserve in SCD mice. Conclusions: SCD mice demonstrate PH, compromised RV function and impaired cardiopulmonary reserve, which mimics clinical cardiopulmonary consequences of SCD and suggests that these mice are a useful tool to investigate mechanical mechanisms of cardiopulmonary progression in SCD.

Effects of left ventricular pressure reductions on right ventricular systolic performance

1989 ◽  
Vol 257 (6) ◽  
pp. H1878-H1885 ◽  
Author(s):  
E. Chow ◽  
D. J. Farrar
Keyword(s):  
Right Ventricular ◽  
Interventricular Septum ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Ventricular Pressure ◽  
Segment Length ◽  
Stroke Work ◽  
Ventricular Performance ◽  
Right Ventricular Performance ◽  
Intact Heart

Reductions in left ventricular pressure (LVP) have been shown to produce a leftward shift of the interventricular septum and to reduce left ventricular contribution to right ventricular performance. To evaluate the magnitude of this contribution in the intact heart, five anesthetized pigs were implanted with a left prosthetic ventricle to gradually decrease LVP while maintaining arterial systemic pressure. Three descriptors of RV global and regional systolic function were studied in the septum to free wall (RVSFW) and anterior to posterior (RVAP) dimensions and in an outflow tract segment length (RVSL), during both steady state and transient inferior vena cava occlusion. LVP gradual reduction from 102 +/- 4 to 11 +/- 3 mmHg (90% decrease in peak systolic pressure) produced no changes in the RV global stroke work curve or in the RVAP and RVSL pressure-dimension relationships. However, the reduction in LVP resulted in parallel shifts in the RVSFW dimension, with 16.6 +/- 6.7% increase in the intercept D(o) of the end-systolic relationship and 16.5 +/- 2.5% increase in D(o) of the dimensional stroke work relationship, with no significant changes in their respective slopes as calculated by linear regression. Therefore, in the normal intact heart, large reductions in left ventricular pressure affect the geometry of the right ventricle because of septal shifting, but there is a negligible net effect of this anatomic ventricular interaction on overall right ventricular performance.

scholarly journals Right ventricular stroke work index by echocardiography in adult patients with pulmonary arterial hypertension

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Raluca Jumatate ◽  
Annika Ingvarsson ◽  
Gustav Jan Smith ◽  
Anders Roijer ◽  
Ellen Ostenfeld ◽  
...  
Keyword(s):  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Right Ventricular ◽  
Adult Patients ◽  
Stroke Work ◽  
Non Invasive ◽  
Work Index ◽  
Stroke Work Index ◽  
Pulmonary Arterial ◽  
Rv Function

Abstract Background In adult patients with pulmonary arterial hypertension (PAH), right ventricular (RV) failure may worsen rapidly, resulting in a poor prognosis. In this population, non-invasive assessment of RV function is challenging. RV stroke work index (RVSWI) measured by right heart catheterization (RHC) represents a promising index for RV function. The aim of the present study was to comprehensively evaluate non-invasive measures to calculate RVSWI derived by echocardiography (RVSWIECHO) using RHC (RVSWIRHC) as a reference in adult PAH patients. Methods Retrospectively, 54 consecutive treatment naïve patients with PAH (65 ± 13 years, 36 women) were analyzed. Echocardiography and RHC were performed within a median of 1 day [IQR 0–1 days]. RVSWIRHC was calculated as: (mean pulmonary arterial pressure (mPAP)—mean right atrial pressure (mRAP)) x stroke volume index (SVI)RHC. Four methods for RVSWIECHO were evaluated: RVSWIECHO-1 = Tricuspid regurgitant maximum pressure gradient (TRmaxPG) x SVIECHO, RVSWIECHO-2 = (TRmaxPG-mRAPECHO) x SVIECHO, RVSWIECHO-3 = TR mean gradient (TRmeanPG) x SVIECHO and RVSWIECHO-4 = (TRmeanPG–mRAPECHO) x SVIECHO. Estimation of mRAPECHO was derived from inferior vena cava diameter. Results RVSWIRHC was 1132 ± 352 mmHg*mL*m−2. In comparison with RVSWIRHC in absolute values, RVSWIECHO-1 and RVSWIECHO-2 was significantly higher (p < 0.001), whereas RVSWIECHO-4 was lower (p < 0.001). No difference was shown for RVSWIECHO-3 (p = 0.304). The strongest correlation, with RVSWIRHC, was demonstrated for RVSWIECHO-2 (r = 0.78, p < 0.001) and RVSWIECHO-1 ( r = 0.75, p < 0.001). RVSWIECHO-3 and RVSWIECHO-4 had moderate correlation (r = 0.66 and r = 0.69, p < 0.001 for all). A good agreement (ICC) was demonstrated for RVSWIECHO-3 (ICC = 0.80, 95% CI 0.64–0.88, p < 0.001), a moderate for RVSWIECHO-4 (ICC = 0.73, 95% CI 0.27–0.87, p < 0.001) and RVSWIECHO-2 (ICC = 0.55, 95% CI − 0.21–0.83, p < 0.001). A poor ICC was demonstrated for RVSWIECHO-1 (ICC = 0.45, 95% CI − 0.18–0.77, p < 0.001). Agreement of absolute values for RVSWIECHO-1 was − 772 ± 385 (− 50 ± 20%) mmHg*mL*m−2, RVSWIECHO-2 − 600 ± 339 (-41 ± 20%) mmHg*mL*m−2, RVSWIECHO-3 42 ± 286 (5 ± 25%) mmHg*mL*m−2 and for RVSWIECHO-4 214 ± 273 (23 ± 27%) mmHg*mL*m−2. Conclusion The correlation with RVSWIRHC was moderate to strong for all echocardiographic measures, whereas only RVSWIECHO-3 displayed high concordance of absolute values. The results, however, suggest that RVSWIECHO-1 or RVSWIECHO-3 could be the preferable echocardiographic methods. Prospective studies are warranted to evaluate the clinical utility of such measures in relation to treatment response, risk stratification and prognosis in patients with PAH.

scholarly journals Programming of growth, insulin resistance and vascular dysfunction in offspring of late gestation diabetic rats

2009 ◽  
Vol 117 (3) ◽  
pp. 129-138 ◽  
Author(s):  
Emily M. Segar ◽  
Andrew W. Norris ◽  
Jian-Rong Yao ◽  
Shanming Hu ◽  
Stacia L. Koppenhafer ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Vascular Function ◽  
Vascular Dysfunction ◽  
Diabetic Rats ◽  
Late Gestation ◽  
Group Differences ◽  
Pregnant Rats ◽  
Increased Risk ◽  
Specific Insulin ◽  
Diabetic Mothers

ODM (offspring of diabetic mothers) have an increased risk of developing metabolic and cardiovascular dysfunction; however, few studies have focused on the susceptibility to disease in offspring of mothers developing diabetes during pregnancy. We developed an animal model of late gestation diabetic pregnancy and characterized metabolic and vascular function in the offspring. Diabetes was induced by streptozotocin (50 mg/kg of body weight, intraperitoneally) in pregnant rats on gestational day 13 and was partially controlled by twice-daily injections of insulin. At 2 months of age, ODM had slightly better glucose tolerance than controls (P<0.05); however, by 6 months of age this trend had reversed. A euglycaemic–hyperinsulinamic clamp revealed insulin resistance in male ODM (P<0.05). In 6–8-month-old female ODM, aortas had significantly enhanced contractility in response to KCl, ET-1 (endothelin-1) and NA (noradrenaline). No differences in responses to ET-1 and NA were apparent with co-administration of L-NNA (NG-nitro-L-arginine). Relaxation in response to ACh (acetylcholine), but not SNP (sodium nitroprusside), was significantly impaired in female ODM. In contrast, males had no between-group differences in response to vasoconstrictors, whereas relaxation to SNP and ACh was greater in ODM compared with control animals. Thus the development of diabetes during pregnancy programmes gender-specific insulin resistance and vascular dysfunction in adult offspring.

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