Stress perfusion cardiovascular magnetic resonance and serial fractional flow reserve assessment of the left anterior descending artery in patients undergoing right coronary artery chronic total occlusion revascularization

Background: Fractional flow reserve (FFR) assessment of remote arteries, in the context of a bystander chronic total occlusion (CTO), can lead to false positive results. Adenosine stress cardiovascular magnetic resonance (CMR) evaluates perfusion defects across the entire myocardium and may therefore be a reliable tool in the work-up of remote lesions in CTO patients. The IMPACT-CTO study investigated donor artery invasive physiology before, immediately post, and at 4 months following right coronary artery (RCA) CTO percutaneous coronary intervention (PCI). The aim of this subanalysis was to assess the concordance between baseline perfusion CMR and serial FFR evaluation of left anterior descending artery (LAD) ischemia in patients from the IMPACT-CTO study.Methods: Baseline adenosine stress CMR examinations from 26 patients were analyzed for qualitative evidence of LAD ischemia. The results were correlated with the serial LAD FFR measurements.Results: The present findings demonstrated that before RCA CTO PCI, there was 62% agreement between perfusion CMR and FFR (ischemic threshold £ 0.8) in the assessment of LAD ischemia (k = 0.29; fair concordance). At 4 months after revascularization, there was 77% agreement (k = 0.52; moderate concordance) between the index CMR assessment of LAD ischemia and the follow-up LAD FFR. Concordance was improved at a LAD FFR ischemic threshold of £ 0.75.Conclusions: In this hypothesis generating study, baseline CMR assessment of LAD ischemia correlated better with the 4 months LAD FFR data (threshold £ 0.8) as compared to the FFR measurements taken prior to RCA CTO revascularization

Noncoronary Gated Transcatheter Aortic Valve Replacement Computed Tomography Scans Can Safely Replace Invasive Coronary Angiography Pre-Transcatheter Aortic Valve Replacement

Description to be added.Cannot be left empt

Influence of pocket shape on numerical response of geocell reinforced foundation systems

Geocells are three-dimensional cellular expandable mats used to improve the load-carrying capacity of weak subgrades. The expanded geocell pockets take the shape of a honeycomb connected to their neighbouring pockets. This manuscript deals with the importance of considering the exact shape of the geocell pockets in three-dimensional numerical modelling. The data for the calibration of the numerical models was obtained through laboratory plate load tests. The numerical simulations were carried out using finite difference software, Fast Lagrangian Analysis of Continua in Three Dimensions (FLAC3D). The walls of the geocell were modelled using geogrid elements having only tensile load capacity. The interfaces between the geocell walls and the infill soils were modelled using Mohr-Coulomb yield criterion. Three shapes of geocell pockets, viz. an exact honeycomb shape and simplified shapes (square and diamond), were considered in the numerical simulations. The numerical models with an exact shape of pockets have shown better agreement with experimental data, while the models with approximated shape overestimated the actual load capacity. The paper describes the modelling approach and the reasons for more accurate numerical predictions with the exact shape of geocell pockets compared to simplified pocket shapes. </jats:p

Relativistic core-envelope anisotropic fluid model of super dense stars

The objective of the present paper is to explore and study an anisotropic spherically symmetric core-envelope model of a super dense star in which core is outfitted with linear equation of state whereas the envelope is considered to be of quadratic equation of state. There is smooth matching between the three regions: the core, envelope and the Schwarzschild exterior metric. We investigate that all the physical and geometrical variables are realistic within the core as well as the envelope of the stellar object and continuous at the junction. Our model is shown to be physically plausible and validate with the intrinsic properties of the neutron star in Vela X-1, SMC X-4 and Her X-1. Further, We infer that with the increase of mass of star the core shrinks, which vindicates the dominating effect of gravity for higher mass astronomical objects

A new parametric class of exact solutions of EFEs under the Karmarkar condition for anisotropic fluids

In this paper, we explore a new parametric class of exact solutions of the Einstein field equations (EFEs) under the Karmarkar condition for anisotropic fluids. The solutions are verified by examining different physical aspects, viz. static stability criterion, energy conditions, stability factor, adiabatic index, causality condition, in connection to their cogency. Due to the well behaved nature of the solutions for different n values, we develop models of objects with different masses and radii, such as PSR J1614-2230, Cen X-1, Her X-1, Vela X-1, LMC X-4 and SMC X-4 and discuss the behavior with a graphical representation of the class of solutions of the first three objects extensively