MODELING OF PRODUCING PRESSURE IN HETEROGENEOUS OIL-BEARING RESERVOIRS

Numerical modeling of the distribution of the reservoir pressure drop in the vicinity of an operating well was carried out taking into account the inhomogeneous distribution of filtration characteristics (permeability and oil viscosity) in the near and distant zones of the well operation in order to study the practical aspects of filtration in heterogeneous oil-bearing formations based on a combined finite-element-difference method for non-stationary problem of piezoconductivity. The use of the combined finite-element-difference method enables to combine the advantages of the finite-element method and the finite difference method: to model geometrically complex areas, to find the value at any point of the object under study, while the implicit difference scheme. It is shown that the intensity of filtration processes in the vicinity of the operating well depends mainly on the permeability, and, to a lesser extent, on the viscosity of the oil. Moreover, the influence of the permeability of the oil phase in the remote zone (Rd < 5 m) is greater than the effect in the close zone (Rd > 5 m) of the operating well. In the case of low permeability of the oil phase in the vicinity of the existing well, to maintain stable oil production, it is necessary to place an injection well near the production well. Using the method suggested, it is possible to predict the effect of the injection well on the formation pressure distribution in the formation. The scientific novelty of the work lies in the study of the influence of the heterogeneous permeability and oil viscosity distribution on the reservoir pressures distribution around the wells by modeling filtration processes based on a combined finite-element-difference method. The practical significance of the research results comes down to confirming the close relationship between the heterogeneity of the porous medium and the reservoir pressures distribution around an operating producing well. The combined finite-element-difference method used in this work can be used to solve other filtration problems (for example, to calculate the gas saturation of a reservoir, create a method for calculating well flow rates, assess the effect of injection wells on filtration processes).

Post Infarction left ventricle remodeling surgical treatment, different ways to get same result

The surgical ventricular restoration is an evolution of treatment of left ventricle aneurysm. The aetioloy of left ventricle aneurysm and the dilated post AMI cardiomiopaty is the same; the difference is in the extension of scarred tissue and in the quality of remote zone. Because in this anatomical situation the geometry of left left ventricle can be deeply affected, it can very difficult to have point of reference as position of apex or papillary mussles. Using a sizer and combine different surgical thecniques allow to rebuilt a ventricle with appropriate volume and shape.

Myocardial Area at Risk and Salvage in reperfused acute MI Measured by Texture Analysis of Cardiac T2 Mapping and Its Prediction Value of Functional Recovery in the Convalescent Stage

To assess the ability of distinguishing the area at risk (AAR) and evaluating the prognostic abilities of T2-mapping texture analysis (TA) in reperfused acute MI, 106 patients who were diagnosed with AMI and treated with percutaneous coronary intervention (PCI) underwent acute (less than five days) enhanced cardiac magnetic resonance imaging. Of these patients, 45 of them had a subsequent CMR scan following recovery (after at least three months). Cine imaging, T2-Mapping, T2-weighted STIR imaging, and LGE imaging were performed. In the TA, regions of interest (infarcted, salvageable, and remote) were drawn by two blinded, independent readers based on LGE and T2-weighted imaging. Seven independent texture features on T2-Mapping were selected: Perc.50%, S(2,2)InvDfMom, S(2.-2)AngScMom, S(4,0)Entropy, 45dgrLngREmph, 45dgr_Fraction and 135dr_GLevNonU. Among them, 45dgr_LngREmph, 45dgr_Fraction and 135dr_GLevNonU showed more promise. The average value of 135dr_GLevNonU in the infarct zone, AAR zone, and the remote zone was: 61.96 ± 26.03, 31.811 ± 18.933 and 99.839 ± 26.231, respectively. Additionally, 135dr_GLevNonU provided the highest 0.855(± 0.083) area under the curve (AUC) from the receiver operating characteristic curve (ROC curve) for distinguishing AAR from the infarct zone. The AUC for differentiating AAR from the remote zone is 0.942 ± 0.041. Texture features are not associated with convalescent decreased strain or ejection fraction (EF) (p > 0.05) in the standard regression analysis; and cannot predict left ventricle remodeling (LVR) in the logistic regression analysis (p > 0.05). T2-mapping TA in reperfused AMI can distinguish AAR from both the infarct zone and the remote myocardial zone without LGE imaging. However, these features cannot predict patients’ functional recovery in the convalescent stage.

Environmental Drivers of Mesophotic Echinoderm Assemblages of the Southeastern Pacific Ocean

Mesophotic ecosystems (50–400 m depth) of the southeastern Pacific have rarely been studied because of the logistical challenges in sampling across this remote zone. This study assessed how oxygen concentrations and other environmental predictors explain variation in echinoderm assemblages at these mesophotic systems, where this group is among the predominant fauna. We compiled data on echinoderm taxa at 91 sampling stations, from historical and recent surveys (between 1950 and 2019), covering a longitudinal gradient of approximately 3,700 km along with the Nazca, Salas y Gómez, and Juan Fernández ridges. Uni- and multivariate model-based tools were applied to analyze the patterns of benthic fauna in relation to environmental factors. Our results indicate a significant positive relationship between echinoderm species richness and depth, oxygen, and salinity. Changes in echinoderm community composition were significantly explained by oxygen, longitude, and chlorophyll-a. We observed notable species turnovers at ∼101 and ∼86°W, where assemblages tend to be more variable across stations. This turnover possibly reflects the effects of physical barriers to dispersion (e.g., currents) and habitat changes. Echinoderm assemblages observed around Easter and Desventuradas Islands presented a high occurrence of potentially endemic taxa and distinct species assemblages. This study is the first to assess the structure of mesophotic echinoderm assemblages of the southeastern Pacific Ocean along a large spatial scale. The information reported here could help design appropriate management tools for the vast, recently created, marine protected areas in the southeastern Pacific.

Abstract 16640: Neutrophil Expansion is Essential for Adverse Left Ventricular Remodeling and Dysfunction in Chronic Ischemic Heart Failure

Chronic inflammation contributes significantly to disease progression in heart failure (HF), and is characterized by expansion of activated macrophages, dendritic cells, and T cells in the failing heart. Neutrophils play a well-known role as the initial drivers of inflammatory response to myocardial infarction (MI), thereby providing the platform for the subsequent recruitment of macrophages and T cells. However, whether and how neutrophils contribute to inflammation and adverse LV remodeling in chronic HF are unknown. We tested the hypothesis that activated neutrophils are required for tissue remodeling and disease progression in HF. Male C57Bl/6 mice were studied 4 and 8 weeks after left coronary artery ligation during established ischemic HF (sham-operated controls). As assessed by flow cytometry, CD11b + Ly6G + neutrophils were expanded in the peripheral blood (4 w post-MI), and in the bone marrow, spleen, and heart at 8 w post-MI. Immunostaining revealed that in the failing heart, neutrophils were primarily localized to the MI border zone, but also augmented in remote zone myocardium. CXCL1 and CXCL5 chemokine expression was increased in the failing heart, consistent with chemotactic signals for myocardial neutrophil recruitment. Isolated naïve neutrophils also exhibited increased chemotaxis in response to plasma from HF mice (versus plasma from naïve mice), as assessed by time-lapse video microscopy. Moreover, blood neutrophils isolated from HF mice exhibited significantly increased neutrophil extracellular trap (NET) production as compared to control neutrophils, whereas plasma NETs (histone-DNA complexes) were increased in HF mice. Finally, the in vivo role of neutrophils in chronic HF (8 w post-MI) was determined via depletion studies using genetic (Ly6G-diptheria toxin receptor mice) and antibody (1A8) based approaches. In both models, 2 and 4 w of neutrophil depletion, respectively, significantly improved LV systolic function and reduced end systolic volume. 1A8 treated HF mice also exhibited reduced remote zone fibrosis. We conclude: neutrophil expansion and activation are important components of the chronic inflammatory response in HF, and play an obligatory role in the progression of LV remodeling in ischemic cardiomyopathy.

Non-invasive myocardial work: an echocardiographic measure of post-infarct scar on contrast-enhanced cardiac magnetic resonance imaging

Background Late gadolinium contrast enhanced cardiac magnetic resonance (LGE CMR) imaging accurately quantifies the extent of fibrosis and transmurality in chronically infarcted left ventricular (LV) segments, and identifies viability. Moreover, CMR characterizes the remote, non-infarcted zone, which is an emerging region of interest following ST-segment elevation myocardial infarction (STEMI). Non-invasive myocardial work is a novel LV function parameter - calculated from speckle-tracking strain echocardiography and sphygmomanometrically-determined blood pressure, which has shown excellent correlation with invasively measured myocardial work. Purpose To explore the relation of non-invasively estimated parameters of LV myocardial work to post-infarct scar on LGE CMR, and to compare myocardial work indices between the infarct core and remote zone in STEMI patients who were treated with primary percutaneous coronary intervention (PCI). Methods Patients with a STEMI who underwent primary PCI and LGE CMR, in addition to echocardiographic studies where non-invasive myocardial work analysis was feasible, were included. The LV was subdivided into non-infarcted, non-transmural and transmurally infarcted segments. The remote zone was defined as the non-infarcted myocardial segment diametrically opposed to the infarct core, without any evidence of LGE. Myocardial work indices were compared with linear mixed models, ANOVA and Wilcoxon signed rank tests. Results 53 patients (89% male, age 58±9 years) and 689 segments were analysed. The mean scar burden comprised 14±7% of the total LV mass and 76 (11%) segments showed transmural LGE. The following non-invasive myocardial work indices: myocardial work index (MWI), constructive work (CW) and myocardial work efficiency (MWE) showed a significant inverse relationship with infarct transmurality (p&lt;0.05 for all comparisons) while a positive trend was observed for wasted work (WW) (p=0.086) (Figure 1). The core zone demonstrated lesser MWI (1237±568 vs. 1514±518 mmHg%; p=0.010), CW (1331±627 vs. 1827±537 mmHg%; p&lt;0.001) and MWE (92 (84–98) vs. 98 (95–99) %; p&lt;0.001) as well as greater WW when compared to the remote zone (107 (26–196) vs. 26 (10–90) mmHg%; p=0.001). Conclusions In STEMI patients who underwent primary PCI, MWI, CW and MWE were significantly related to the extent of transmural infarction, while WW demonstrated a trend. MWI, CW and MWE were significantly lower, and WW higher, in the core zone compared to the remote zone. Non-invasive myocardial work indices may provide an echocardiographic method for determining post-infarct viability, as well as characterization of the remote zone. MW and scar transmurality on LGE CMR Funding Acknowledgement Type of funding source: None

Nonocclusive multivessel intracoronary infusion of allogeneic cardiosphere-derived cells early after reperfusion prevents remote zone myocyte loss and improves global left ventricular function in swine with myocardial infarction

Intracoronary cardiosphere-derived cells (icCDCs) infused into the infarct-related artery reduce scar volume but do not improve left ventricular (LV) ejection fraction (LVEF). We tested the hypothesis that this reflects the inability of regional delivery to prevent myocyte death or promote myocyte proliferation in viable myocardium remote from the infarct. Swine ( n = 23) pretreated with oral cyclosporine (200 mg/day) underwent a 1-h left anterior descending coronary artery (LAD) occlusion, which reduced LVEF from 61.6 ± 1.0 to 45.3 ± 1.5% 30 min after reperfusion. At that time, animals received global infusion of allogeneic icCDCs ( n = 8), regional infusion of icCDCs restricted to the LAD using the stop-flow technique ( n = 8), or vehicle ( n = 7). After 1 mo, global icCDCs increased LVEF from 44.8 ± 1.9 to 60.8 ± 3.8% ( P < 0.05) with no significant change after LAD stop-flow icCDCs (44.8 ± 3.6 to 50.9 ± 3.1%) or vehicle (46.5 ± 2.5 to 47.7 ± 2.6%). In contrast, global icCDCs did not alter infarct volume (%LV mass) assessed at 2 days (11.2 ± 2.3 vs. 12.6 ± 2.3%), whereas it was reduced after LAD stop-flow icCDCs (7.1 ± 1.1%, P < 0.05). Histopathological analysis of remote myocardium after global icCDCs demonstrated a significant increase in myocyte proliferation (147 ± 32 vs. 14 ± 10 nuclei/106 myocytes, P < 0.05) and a reduction in myocyte apoptosis (15 ± 9 vs. 46 ± 10 nuclei/106 myocytes, P < 0.05) that increased myocyte nuclear density (1,264 ± 39 vs. 1,157 ± 33 nuclei/mm2, P < 0.05) and decreased myocyte diameter (13.2 ± 0.2 vs. 14.5 ± 0.3 μm, P < 0.05) compared with vehicle-treated controls. In contrast, remote zone changes after regional LAD icCDCs were no different from vehicle. These data indicate that changes in global LVEF after icCDCs are dependent upon preventing myocyte loss and hypertrophy in myocardium remote from the infarct. These arise from stimulating myocyte proliferation and reducing myocyte apoptosis indicating the importance of directing cell therapy to viable remote regions. NEW & NOTEWORTHY Administration of allogeneic cardiosphere-derived cells to the entire heart via global intracoronary infusion shortly after myocardial infarction favorably influenced left ventricular ejection fraction by preventing myocyte death and promoting myocyte proliferation in remote, noninfarcted myocardium in swine. In contrast, regional intracoronary cell infusion did not significantly affect remote zone myocyte remodeling. Global cell administration targeting viable myocardium remote from the infarct may be an effective approach to prevent adverse ventricular remodeling after myocardial infarction.

Complex electrophysiological remodeling in postinfarction ischemic heart failure

Heart failure (HF) following myocardial infarction (MI) is associated with high incidence of cardiac arrhythmias. Development of therapeutic strategy requires detailed understanding of electrophysiological remodeling. However, changes of ionic currents in ischemic HF remain incompletely understood, especially in translational large-animal models. Here, we systematically measure the major ionic currents in ventricular myocytes from the infarct border and remote zones in a porcine model of post-MI HF. We recorded eight ionic currents during the cell’s action potential (AP) under physiologically relevant conditions using selfAP-clamp sequential dissection. Compared with healthy controls, HF-remote zone myocytes exhibited increased late Na+ current, Ca2+-activated K+ current, Ca2+-activated Cl− current, decreased rapid delayed rectifier K+ current, and altered Na+/Ca2+ exchange current profile. In HF-border zone myocytes, the above changes also occurred but with additional decrease of L-type Ca2+ current, decrease of inward rectifier K+ current, and Ca2+ release-dependent delayed after-depolarizations. Our data reveal that the changes in any individual current are relatively small, but the integrated impacts shift the balance between the inward and outward currents to shorten AP in the border zone but prolong AP in the remote zone. This differential remodeling in post-MI HF increases the inhomogeneity of AP repolarization, which may enhance the arrhythmogenic substrate. Our comprehensive findings provide a mechanistic framework for understanding why single-channel blockers may fail to suppress arrhythmias, and highlight the need to consider the rich tableau and integration of many ionic currents in designing therapeutic strategies for treating arrhythmias in HF.