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• Combining information derived from both the amplitude and shape of right ventricular pressure waveform with other data sources provides the basis for a more comprehensive bedside assessment of right ventricular function. Continuous measurement of pressure in the right atrium and pulmonary artery has commonly been used to monitor right ventricular function in critically ill and surgical patients. This approach is largely based upon the assumption that right atrial and pulmonary arterial pressures provide accurate surrogates for diastolic filling and peak right ventricular pressures, respectively. However, due to both technical and physiologic factors, this assumption is not always true. Accordingly, recent studies have begun to emphasize the potential clinical value of also measuring right ventricular pressure at the bedside. This has highlighted both past and emerging research demonstrating the utility of analyzing not only the amplitude of right ventricular pressure but also the shape of the pressure waveform. This brief review summarizes data demonstrating that combining conventional measurements of right ventricular pressure with variables derived from waveform shape allows for more comprehensive and ideally continuous bedside assessment of right ventricular function, particularly when combined with stroke volume measurement or 3D echocardiography, and discusses the potential use of right ventricular pressure analysis in computational models for evaluating cardiac function. [ABSTRACT FROM AUTHOR]

Background: The role of interventricular mechanics in pediatric pulmonary arterial hypertension (PAH) and its relation to right ventricular (RV) dysfunction has been largely overlooked. Here, we characterize the impact of maintained pressure overload in the RV–pulmonary artery (PA) axis on myocardial strain and left ventricular (LV) mechanics in pediatric PAH patients in comparison to a preclinical PA-banding (PAB) mouse model. We hypothesize that the PAB mouse model mimics important aspects of interventricular mechanics of pediatric PAH and may be beneficial as a surrogate model for some longitudinal and interventional studies not possible in children. Methods: Balanced steady-state free precession (bSSFP) cardiovascular magnetic resonance (CMR) images of 18 PAH and 17 healthy (control) pediatric subjects were retrospectively analyzed using CMR feature-tracking (FT) software to compute measurements of myocardial strain. Furthermore, myocardial tagged-CMR images were also analyzed for each subject using harmonic phase flow analysis to derive LV torsion rate. Within 48 h of CMR, PAH patients underwent right heart catheterization (RHC) for measurement of PA/RV pressures, and to compute RV end-systolic elastance (RV_Ees, a measure of load-independent contractility). Surgical PAB was performed on mice to induce RV pressure overload and myocardial remodeling. bSSFP-CMR, tagged CMR, and intra-cardiac catheterization were performed on 12 PAB and 9 control mice (Sham) 7 weeks after surgery with identical post-processing as in the aforementioned patient studies. RV_Ees was assessed via the single beat method. Results: LV torsion rate was significantly reduced under hypertensive conditions in both PAB mice (p = 0.004) and pediatric PAH patients (p < 0.001). This decrease in LV torsion rate correlated significantly with a decrease in RV_Ees in PAB (r = 0.91, p = 0.05) and PAH subjects (r = 0.51, p = 0.04). In order to compare combined metrics of LV torsion rate and strain parameters principal component analysis (PCA) was used. PCA revealed grouping of PAH patients with PAB mice and control subjects with Sham mice. Similar to LV torsion rate, LV global peak circumferential, radial, and longitudinal strain were significantly (p < 0.05) reduced under hypertensive conditions in both PAB mice and children with PAH. Conclusions: The PAB mouse model resembles PAH-associated myocardial mechanics and may provide a potential model to study mechanisms of RV/LV interdependency. [ABSTRACT FROM AUTHOR]

Objective Central aortic stiffness and chronic obstructive pulmonary disease (COPD) are associated with increased incidence of devastating aortopathies. However, the exact mechanism leading to elevated aortic stiffness in patients with COPD is unknown. The purpose of this study was to quantify flow and shear hemodynamic indices, known markers of vascular remodeling, in the thoracic aorta of patients with mild to moderate COPD (n = 16) and to compare these results with an age-matched control group (n = 10). Methods Four-dimensional flow magnetic resonance imaging has been applied to measure hemodynamic wall shear stress (WSS) at four specific planes along the ascending aorta, aortic arch, and proximal descending aorta for all subjects. Peak systolic WSS and time-averaged WSS, which respectively reflect magnitude and temporal shear variability, were calculated at standardized planes. Aortic deformation was measured by means of relative area change (RAC) at the midlevel of the ascending and descending aorta. Results Compared with controls, patients with COPD had significantly reduced RAC in the mid ascending aorta (9% vs 18%; P < .0001) and descending aorta (15% vs 19%; P = .0206). Peak systolic WSS in COPD patients was significantly reduced in all considered planes, with the most dramatic difference occurring in the descending aorta (0.46 vs 0.86 N/m 2 ; P < .0001). Peak systolic WSS and time-averaged WSS were both significantly correlated with aortic RAC at each evaluated plane. Conclusions Reduced flow shear metrics assessed at specific aortic regions correlated with RAC, a marker of aortic stiffness. Reduced hemodynamic WSS may then contribute to central aortic stiffening and perpetuate the risk for development of severe aortopathy. [ABSTRACT FROM AUTHOR]

The algorithms of constructing geometrically accurate real computer 3d models are developed. The special feature of these algorithms is that they reproduce a technological process of manufacturing components. The examples of constructing spur and helical gear sets, bevel gears, Archimedes and globoid gear pairs are given. The accuracy of construction is estimated. The construction inaccuracy doesn’t exceed a part of μm, which enables one to use the models as computer samples for production accuracy control and the algorithms as a basis for programs of components production with the help of the programmed control machine tools. The programs for implementation of the suggested algorithms are developed. The programs enable one to vary numerous model parameters and take into consideration teeth forms. The applicability of programs for the analysis of geometric properties of the models is shown. The model of a worm wheel root surface is received. The kinematic surface formed in the globoid gear is examined. The author presents the model of milling of a gear wheel, where the impact of cutting parameters on the tooth form of a manufactured wheel is examined. The models are constructed in the AutoCAD package. These programs are AutoLisp-based. [ABSTRACT FROM AUTHOR]

In the U.S, a wide body of evidence has documented significant racial-ethnic disparities in women's health, and growing attention has focused on discrimination in health care as an underlying cause. Yet, there are knowledge gaps on how experiences of racial-ethnic health care discrimination across the life course influence the health of women of color. Our objective was to summarize existing literature on the impact of racial-ethnic health care discrimination on health care outcomes for women of color to examine multiple health care areas encountered across the life course. We systematically searched three databases and conducted study screening, data extraction, and quality assessment. We included quantitative and qualitative peer-reviewed literature on racial-ethnic health care discrimination towards women of color, focusing on studies that measured patient-perceived discrimination or differential treatment resulting from implicit provider bias. Results were summarized through narrative synthesis. In total, 84 articles were included spanning different health care domains, such as perinatal and cancer care. Qualitative studies demonstrated the existence of racial-ethnic discrimination across care domains. Most quantitative studies reported a mix of positive and null associations between discrimination and adverse health care outcomes, with variation by the type of health care outcome. For instance, over three-quarters of the studies exploring associations between discrimination/bias and health care-related behaviors or beliefs found significant associations, whereas around two-thirds of the studies on clinical interventions found no significant associations. This review shows substantial evidence on the existence of racial-ethnic discrimination in health care and its impact on women of color in the U.S. However, the evidence on how this phenomenon influences health care outcomes varies in strength by the type of outcome investigated. High-quality, targeted research using validated measures that is grounded in theoretical frameworks on racism is needed. This systematic review was registered [PROSPERO ID: CRD42018105448]. • Racial-ethnic health care discrimination affects women of color across the life course. • Qualitative research documents health care discrimination across many domains. • Evidence on the impact of discrimination varies by type of health care outcome. • Evidence is strongest for effects on health care-related beliefs and behaviors. • Gaps exist in research on racial-ethnic health care discrimination in women's health. [ABSTRACT FROM AUTHOR]

Background: Pediatric pulmonary hypertension (PH) remains a disease with high morbidity and mortality in children. Understanding ventricular-vascular coupling, a measure of how well matched the ventricular and vascular function are, may elucidate pathway leading to right heart failure. Ventricular vascular coupling ratio (VVCR), comprised of effective elastance (Ea, index of arterial load) and right ventricular maximal end-systolic elastance (Ees, index of contractility), is conventionally determined by catheterization. Here, we apply a non-invasive approach to determining VVCR in pediatric subjects with PH. Methods: This retrospective study included PH subjects who had a cardiovascular magnetic resonance (CMR) study within 14 days of cardiac catheterization. PH was defined as mean pulmonary artery pressure (mPAP) ≥ 25 mmHg on prior or current catheterization. A non-invasive measure of VVCR was derived from CMR-only (VVCRm) and compared to VVCR estimated by catheterization-derived single beat estimation (VVCRs). Indexed pulmonary vascular resistance (PVRi) and pulmonary vascular reactivity were determined during the catheterization procedure. Pearson correlation coefficients were calculated between PVRi and VVCRm. Receiver operating characteristic (ROC) curve analysis determined the diagnostic value of VVCRm in predicting vascular reactivity. Results: Seventeen subjects (3 months-23 years; mean 11.3 ± 7.4 years) were identified between January 2009-August 2013 for inclusion with equal gender distributions. Mean mPAP was 35 mmHg ± 15 and PVRi was 8.5 Woods unit x m2 ± 7.8. VVCRm (range 0.43-2.82) increased with increasing severity as defined by PVRi (p < 0.001), and was highly correlated with PVRi (r = 0.92, 95 % CI 0.79-0.97, p < 0.0001). Regression of VVCRm and PVRi demonstrated differing lines when separated by reactivity. VVCRm was significantly correlated with VVCRs (r= 0.79, CI 0.48-0.99, p <0.0001). ROC curve analysis showed high accuracy of VVCRm in determining vascular reactivity (VVCR = 0.85 had a sensitivity of 100 % and a specificity of 80 %) with an area under the curve of 0.89 (p = 0.008). Conclusion: Measurement of VVCRm in pediatrics is feasible. Pulmonary vascular non-reactivity may be contribute to ventricular-vascular decoupling in severe PH. Therapeutic intervention to maintain a low vascular afterload in reactive patients may preserve right ventricular functional reserve and delay the onset of RV-PA decoupling. Use of VVCRm may have significant prognostic implication. [ABSTRACT FROM AUTHOR]

Computational fluid dynamics (CFD) modeling of the pulmonary vasculature has the potential to reveal continuum metrics associated with the hemodynamic stress acting on the vascular endothelium. It is widely accepted that the endothelium responds to flow-induced stress by releasing vasoactive substances that can dilate and constrict blood vessels locally. The objectives of this study are to examine the extent of patient specificity required to obtain a significant association of CFD output metrics and clinical measures in models of the pulmonary arterial circulation, and to evaluate the potential correlation of wall shear stress ( WSS ) with established metrics indicative of right ventricular (RV) afterload in pulmonary hypertension (PH). Right Heart Catheterization (RHC) hemodynamic data and contrast-enhanced computed tomography (CT) imaging were retrospectively acquired for 10 PH patients and processed to simulate blood flow in the pulmonary arteries. While conducting CFD modeling of the reconstructed patient-specific vasculatures, we experimented with three different outflow boundary conditions to investigate the potential for using computationally derived spatially averaged wall shear stress ( SAWSS ) as a metric of RV afterload. SAWSS was correlated with both pulmonary vascular resistance ( PVR ) ( R 2 = 0.77, P < 0.05) and arterial compliance ( C ) ( R 2 = 0.63, P < 0.05), but the extent of the correlation was affected by the degree of patient specificity incorporated in the fluid flow boundary conditions. We found that decreasing the distal PVR alters the flow distribution and changes the local velocity profile in the distal vessels, thereby increasing the local WSS . Nevertheless, implementing generic outflow boundary conditions still resulted in statistically significant SAWSS correlations with respect to both metrics of RV afterload, suggesting that the CFD model could be executed without the need for complex outflow boundary conditions that require invasively obtained patient-specific data. A preliminary study investigating the relationship between outlet diameter and flow distribution in the pulmonary tree offers a potential computationally inexpensive alternative to pressure based outflow boundary conditions. [ABSTRACT FROM AUTHOR]

Highlights: [•] Model of 3D, constant-volume, free surface, gravity-driven flow of Ellis fluid. [•] Parametric study of Ellis parameters on spreading length and velocity saturation. [•] Application of thin film equation to non-Newtonian fluid in biomedical flow. [•] The effect of shear-thinning on front speed saturation depends on other parameters. [ABSTRACT FROM AUTHOR]

Abstract: The objective of this work is to develop a robust method for human abdominal aortic aneurysm (AAA) centerline detection that can contribute to the accurate computation of features for the prediction of AAA rupture risk. A semiautomatic algorithm is proposed for detecting the lumen centerline in contrast-enhanced abdominal computed tomography images based on online adaboost classifiers, which does not require prior image segmentation. The algorithm was developed and applied to thirty ruptured and thirty unruptured AAA image data sets and the tortuosities of the detected centerline were measured to assess the correlation between AAA tortuosity and the binary ruptured and unruptured labels. The lumen of each data set was segmented manually by a trained radiologist and the resulting centerlines of each data set were defined as the gold standard to evaluate the accuracy of the algorithm and to compare it against two widely used segmentation techniques. The average mean relative accuracy of the offline adaboost classifier is 91.9% with a standard deviation of 1.6%; for the online adaboost classifier it is 93.6% with a standard deviation of 1.9% (p <0.05). The online adaboost classifier outperforms the offline adaboost classifier while their computational costs are similar. Aneurysm tortuosity computed from an accurately derived lumen centerline using online adaboost is statistically higher for ruptured aneurysms compared to unruptured aneurysms, indicating that tortuosity can be used to assess rupture risk in the vascular clinic. [Copyright &y& Elsevier]

Postcircumcision bleeding can be the presenting symptom of a coagulopathy. A blood dyscrasia that is known but not documented in association with circumcision is neonatal alloimmune thrombocytopenia (NAIT). A 2-day-old male infant presented with postcircumcision bleeding. Platelet count was 5000 per microliter of blood. The child was treated conservatively with hematoma improvement. Few studies exist involving patients with coagulopathies who undergo circumcision. Our patient is the first to present with prolonged postcircumcision bleeding as the initial presentation of NAIT. NAIT and other coagulopathies that present as prolonged postcircumcision bleeding can often be managed successfully with conservative management. [ABSTRACT FROM AUTHOR]

Exposure to stress during the prenatal period is often associated with adverse maternal and neonatal health outcomes and is increasing in prevalence in the United States. Health care providers play a crucial role in addressing and mitigating this stress, but there is a lack of consensus regarding effective interventions. This review evaluates the effectiveness of prenatal provider-based interventions that reduce stress for pregnant people, especially those who are disproportionately affected by stress. A search of relevant English-language literature was conducted using PubMed, CINAHL, Web of Science, Embase, and PyscInfo. Inclusion criteria were 1) the target population was pregnant people, 2) the intervention was delivered within the U.S. health care system, and 3) the study intervention had the goal of reducing stress (stress-reducing intervention). A total of 3,562 records were identified in the search and 23 were included in analysis. The four identified categories for provider-led stress-reducing prenatal interventions included in the review are 1) skills-building, 2) mindfulness, 3) behavioral therapy, and 4) group support. Findings suggest an increased overall likelihood of mood and maternal stress improvement among pregnant people who complete provider-based stress-reducing interventions, especially group-based therapies that integrate resource allocation, skills-building, mindfulness, and/or behavioral therapy into an intersectional program. However, the efficacy of each type of intervention varies by category and type of maternal stress targeted. Although few studies demonstrated a significant reduction in stress for pregnant people, this review highlights the critical need for increased research and attention to stress-reducing interventions in the prenatal period, especially as it pertains to minoritized populations. [ABSTRACT FROM AUTHOR]

Abstract: There is mounting evidence that exercise tolerance is an important predictor of heart disease. Our objective was to determine if decreased exercise tolerance, as estimated by physicians, may be useful in stratifying risk in Emergency Department (ED) patients with potential acute coronary syndromes. We conducted a prospective cohort study on a convenience sample of ED patients at an urban teaching hospital. Patients with chest pain, dyspnea, syncope, or epigastric pain who were evaluated for acute coronary syndromes were included. Clinical and laboratory data were recorded. In addition, the Emergency Physicians were asked to estimate the exercise tolerance of the patient as excellent, good, bad, or very poor. The primary outcome of the study was myocardial infarction (MI) or death in patients stratified by physician-perceived exercise tolerance (excellent or good vs. bad or very poor). There were 166 patients enrolled in the study. Nine patients (5%) had an MI; there were no deaths. Physicians reported exercise tolerance as excellent in 33 patients, good in 63, bad in 50, and very poor in 20. The unadjusted risk of MI was significantly elevated in patients with physician-perceived decreased exercise tolerance (relative risk = 4.8, 95% confidence interval 1.03–22). After adjustment for age, sex, and major cardiovascular risk factors, decreased exercise tolerance remained a significant predictor of MI (adjusted odds ratio = 7.3, 95% confidence interval 1.2–46). Exercise tolerance, as estimated by clinical impression, may be an important predictor of complications in ED patients presenting with potential acute coronary syndromes. [Copyright &y& Elsevier]