Pulmonary vascular resistance after cardiopulmonary bypass in infants: Effect on postoperative recovery

AbstractObjective: We sought to define the contemporary clinical effect of increased pulmonary vascular resistance in infants after congenital heart operations with cardiopulmonary bypass. Methods: Fifteen infants (median age, 0.31 years; median weight, 5.1 kg) underwent cardiac operations involving cardiopulmonary bypass (range, 49-147 minutes). Pulmonary vascular resistance was measured in the immediate postoperative period in the intensive care unit by means of the direct Fick principle, with respiratory mass spectrometry to measure oxygen consumption. The effect of ventilation with an inspired oxygen fraction of 0.65, with additional infusion of L -arginine, substance P, and inhaled nitric oxide, was assessed and subsequently correlated with the length of mechanical ventilation from the end of cardiopulmonary bypass to successful extubation. Results: Overall, pulmonary vascular resistance at baseline (11.7 ± 5.6 WU · m2) could be reduced to a minimum of 6.1 ± 3.5 WU · m2. The ventilatory time was 0.86 to 14.9 days (median, 1.75 days) and correlated directly with the lowest pulmonary vascular resistance value achieved during the pulmonary vascular resistance study (r 2 = 0.64, P <.01). The patient subgroup with mechanical ventilation of greater than 2 days had significantly higher pulmonary vascular resistance at all stages of the study protocol, and in this group there was a correlation of cardiopulmonary bypass time and ventilatory support time (r 2 = 0.48, P <.05). Conclusion: Increased pulmonary vascular resistance, either directly or as a surrogate of the systemic inflammatory response after cardiopulmonary bypass, continues to have a significant effect on postoperative recovery of infants after cardiac operations. (J Thorac Cardiovasc Surg 2001;121:1033-9

Numerical method of characteristics for one-dimensional blood flow

Mathematical modeling at the level of the full cardiovascular system requires the numerical approximation of solutions to a one-dimensional nonlinear hyperbolic system describing flow in a single vessel. This model is often simulated by computationally intensive methods like finite elements and discontinuous Galerkin, while some recent applications require more efficient approaches (e.g. for real-time clinical decision support, phenomena occurring over multiple cardiac cycles, iterative solutions to optimization/inverse problems, and uncertainty quantification). Further, the high speed of pressure waves in blood vessels greatly restricts the time step needed for stability in explicit schemes. We address both cost and stability by presenting an efficient and unconditionally stable method for approximating solutions to diagonal nonlinear hyperbolic systems. Theoretical analysis of the algorithm is given along with a comparison of our method to a discontinuous Galerkin implementation. Lastly, we demonstrate the utility of the proposed method by implementing it on small and large arterial networks of vessels whose elastic and geometrical parameters are physiologically relevant

Editorial Board Composition Among Pediatric Cardiology Journals:Time to Cast the Net Wider

Background: No data currently exist on the diversity of editorial board members (EBMs) of pediatric cardiology journals. Objectives: The objective was to investigate the editorial boards of 5 pediatric cardiology journals to assess the composition of these boards in terms of the geographical, gender, and economic representation of their members. Methods: Information on EBMs was collected directly from 5 journal websites accessed in February 2022. The following data were collected: country of practice (including World Bank geographical and income classification), institution of practice, role on editorial board, and whether an individual held a role on 1 or more of the boards included. Results: A total of 455 EBMs were identified. A total of 369 (81%) were male. All editors-in-chief were male, and 4 were from the United States. EBMs practicing in North America accounted for 278 individuals (61%) of the editorial boards reviewed. The next majority of EBMs are practicing within Europe and Central Asia (23%, n = 103), East Asia and Pacific (7%, n = 31), Middle East and North Africa (4%, n = 18), and Latin America and Caribbean (4%, n = 16). Less than 2% (n = 9) practice in Sub-Saharan Africa and South Asia. Over 90% (n = 415) practice in high-income countries. There was no representation from low-income countries. Conclusions: Women and pediatric cardiologists practicing in countries outside of Europe and North America were underrepresented on the editorial boards of the journals studied. Diversifying composition of editorial boards may provide greater representation of underserved areas and encourage broader avenues of investigation and research

Phase light curves for extrasolar Jupiters and Saturns

We predict how a remote observer would see the brightness variations of giant planets similar to Jupiter and Saturn as they orbit their central stars. We model the geometry of Jupiter, Saturn and Saturn's rings for varying orbital and viewing parameters. Scattering properties for the planets and rings at wavelenghts 0.6-0.7 microns follow Pioneer and Voyager observations, namely, planets are forward scattering and rings are backward scattering. Images of the planet with or without rings are simulated and used to calculate the disk-averaged luminosity varying along the orbit, that is, a light curve is generated. We find that the different scattering properties of Jupiter and Saturn (without rings) make a substantial difference in the shape of their light curves. Saturn-size rings increase the apparent luminosity of the planet by a factor of 2-3 for a wide range of geometries. Rings produce asymmetric light curves that are distinct from the light curve of the planet without rings. If radial velocity data are available for the planet, the effect of the ring on the light curve can be distinguished from effects due to orbital eccentricity. Non-ringed planets on eccentric orbits produce light curves with maxima shifted relative to the position of the maximum planet's phase. Given radial velocity data, the amount of the shift restricts the planet's unknown orbital inclination and therefore its mass. Combination of radial velocity data and a light curve for a non-ringed planet on an eccentric orbit can also be used to constrain the surface scattering properties of the planet. To summarize our results for the detectability of exoplanets in reflected light, we present a chart of light curve amplitudes of non-ringed planets for different eccentricities, inclinations, and the viewing azimuthal angles of the observer.Comment: 40 pages, 13 figures, submitted to Ap.

The endothelin antagonist BQ123 reduces pulmonary vascular resistance after surgical intervention for congenital heart disease

AbstractObjective: Postoperative pulmonary hypertension in children after surgical intervention for congenital heart disease has been attributed to failure of the pulmonary endothelium to provide adequate vasodilation. Although we have shown that the impaired vasodilatory component attributable to the l-arginine-nitric oxide pathway is almost completely reversible, a nonrestorable component persists, implying an additional vasoconstrictive mechanism in postoperative pulmonary endothelial dysfunction. In this study of children after surgical intervention for congenital heart disease, we measured endothelin-1 levels and used BQ123, a selective endothelin-A receptor antagonist, together with inhaled nitric oxide to discriminate dysfunctional pulmonary endothelial vasodilation from endothelin-mediated pulmonary vasoconstriction. Methods: All children were examined early after surgical intervention in the intensive care unit. Pulmonary vascular resistance (with respiratory mass spectrometry), as well as arterial and venous endothelin-1 levels (measured by means of a quantitative enzyme-linked immunosorbent assay), were determined in 7 children (age range, 3.3-13.7 months; median age, 6.3 months) with intracardiac shunting defects at baseline and during ventilation with a fraction of inspired oxygen of 0.65, with additional BQ123 (0.1 mg/kg infused over 20 minutes), and with inhaled nitric oxide (20 ppm). Results: Pulmonary vascular resistance decreased from 7.7 ± 3.4 at baseline to 6.1 ± 2.8 Woods units · m−2 (P =.022) at a fraction of inspired oxygen of 0.65 and to 4.7 ± 2.7 Woods units · m−2 (P =.013) during BQ123 infusion. Inhaled nitric oxide had no further effect on pulmonary vascular resistance. Left atrial endothelin-1 levels (1.35-5.12 pg/mL; mean, 2.4 pg/mL) correlated significantly with the decrease in pulmonary vascular resistance in response to BQ123 infusion (r2 = 0.89, P =.003). Conclusion: Postoperative elevation of pulmonary vascular resistance in children after surgical intervention for congenital heart disease is responsive to endothelin-A blockade with BQ123. Increased levels of endothelin-1 predict the response to this therapy, which might become an important addition to the clinical armamentarium in postoperative pulmonary hypertensive disease.J Thorac Cardiovasc Surg 2002;124:435-4

Microwave-assisted synthesis of layered basic zinc acetate nanosheets and their thermal decomposition into nanocrystalline ZnO

We have developed a low-cost technique using a conventional microwave oven to grow layered basic zinc acetate (LBZA) nanosheets (NSs) from a zinc acetate, zinc nitrate and HMTA solution in only 2 min. The as-grown crystals and their pyrolytic decomposition into ZnO nanocrystalline NSs are characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), X-ray diffraction (XRD) and photoluminescence (PL). SEM and AFM measurements show that the LBZA NSs have typical lateral dimensions of 1 to 5 μm and thickness of 20 to 100 nm. Annealing in air from 200°C to 1,000°C results in the formation of ZnO nanocrystalline NSs, with a nanocrystallite size ranging from 16 nm at 200°C to 104 nm at 1,000°C, as determined by SEM. SEM shows evidence of sintering at 600°C. PL shows that the shape of the visible band is greatly affected by the annealing temperature and that the exciton band to defect band intensity ratio is maximum at 400°C and decreases by a factor of 15 after annealing at 600°C. The shape and thickness of the ZnO nanocrystalline NSs are the same as LBZA NSs. This structure provides a high surface-to-volume ratio of interconnected nanoparticles that is favorable for applications requiring high specific area and low resistivity such as gas sensing and dye-sensitized solar cells (DSCs). We show that resistive gas sensors fabricated with the ZnO NSs showed a response of 1.12 and 1.65 to 12.5 ppm and 200 ppm of CO at 350°C in dry air, respectively, and that DSCs also fabricated from the material had an overall efficiency of 1.3%

Antidepressant and antipsychotic drug prescribing and diabetes outcomes: A systematic review of observational studies

AIMS: Psychotropic medication may be associated with adverse effects, including among people with diabetes. We conducted a systematic review of observational studies investigating the association between antidepressant or antipsychotic drug prescribing and type 2 diabetes outcomes. METHODS: We systematically searched PubMed, EMBASE, and PsycINFO to 15th August 2022 to identify eligible studies. We used the Newcastle-Ottawa scale to assess study quality and performed a narrative synthesis. RESULTS: We included 18 studies, 14 reporting on antidepressants and four on antipsychotics. There were 11 cohort studies, one self-controlled before and after study, two case-control studies, and four cross-sectional studies, of variable quality with highly heterogeneous study populations, exposure definitions, and outcomes analysed. Antidepressant prescribing may be associated with increased risk of macrovascular disease, whilst evidence on antidepressant and antipsychotic prescribing and glycaemic control was mixed. Few studies reported microvascular outcomes and risk factors other than glycaemic control. CONCLUSIONS: Studies of antidepressant and antipsychotic drug prescribing in relation to diabetes outcomes are scarce, with shortcomings and mixed findings. Until further evidence is available, people with diabetes prescribed antidepressants and antipsychotics should receive monitoring and appropriate treatment of risk factors and screening for complications as recommended in general diabetes guidelines

Inherited Cardiomyopathies: Genetics and Clinical Genetic Testing

Inherited cardiomyopathies are major causes of morbidity and mortality and include a group of cardiac disorders such as hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy, arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C), left ventricular noncompaction (LVNC), and restrictive cardiomyopathy (RCM). These diseases have a substantial genetic component and predispose to sudden cardiac death. Since the first gene was identified as a disease-causing gene for HCM over two decades ago, more than eighty genes have been identified to be associated with inherited cardiomyopathies and genetic testing has become prevalent in making clinical diagnosis. With the advent of next-generation sequencing technology, genetic panel testing of inherited cardiomyopathies has become feasible and cost efficient. In this review, we summarize the individual cardiomyopathies with the emphasis on cardiomyopathy genetics and genetic testing