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https://www.readbyqxmd.com/read/28797433/periprocedural-myocardial-injury-depends-on%C3%A2-transcatheter-heart-valve-type-but-does%C3%A2-not%C3%A2-predict-mortality-in-patients-after-transcatheter-aortic-valve-replacement
#1
Anja Stundl, Regina Schulte, Hannah Lucht, Marcel Weber, Alexander Sedaghat, Jasmin Shamekhi, Berndt Zur, Eberhard Grube, Fritz Mellert, Armin Welz, Rolf Fimmers, Georg Nickenig, Nikos Werner, Jan-Malte Sinning
OBJECTIVES: The aims of this study were to determine plasma elevations of biomarkers of myocardial injury associated with transfemoral (TF) transcatheter aortic valve replacement (TAVR) and to evaluate their prognostic value. BACKGROUND: Increases in biomarkers of myocardial injury are a common finding after TAVR, but their clinical significance is unclear. METHODS: In 756 consecutive TF TAVR patients, cardiac high-sensitivity troponin I (hsTnI) and creatine kinase MB (CK-MB) levels were measured at pre-defined time points to assess the occurrence of myocardial injury (defined as 15 times the upper reference limit for hsTnI [≥1...
August 14, 2017: JACC. Cardiovascular Interventions
https://www.readbyqxmd.com/read/28793899/enumeration-of-circulating-endothelial-cell-frequency-as-a-diagnostic-marker-in-aortic-valve-surgery-a-flow-cytometric-approach
#2
Anton Sabashnikov, Klaus Neef, Vera Chesnokova, Leonie Wegener, Kathrin Godthardt, Maximilian Scherner, Elmar W Kuhn, Antje-Christin Deppe, Meike Lauer, Kaveh Eghbalzadeh, Mohamed Zeriouh, Parwis B Rahmanian, Jens Wippermann, Ferdinand Kuhn-Régnier, Navid Madershahian, Thorsten Wahlers, Alexander Weymann, Yeong-Hoon Choi
BACKGROUND: The frequency of circulating endothelial cells (CEC) in patients' peripheral blood can be assessed as a direct marker of endothelial damage. However, conventional enumeration methods are extremely challenging. We developed a novel, automated approach to determine CEC frequencies and tested this method on two groups of patients undergoing conventional (CAVR) versus trans-catheter aortic valve implantation (TAVI). METHODS: CEC frequencies were assessed by a flow cytometric approach, including automated pre-enrichment of CD34 positive blood cell subpopulation and isotype controls...
August 9, 2017: Journal of Cardiothoracic Surgery
https://www.readbyqxmd.com/read/28793046/influence-of-the-tilt-angle-of-percutaneous-aortic-prosthesis-on-velocity-and-shear-stress-fields
#3
Bruno Alvares de Azevedo Gomes, Gabriel Cordeiro Camargo, Jorge Roberto Lopes Dos Santos, Luis Fernando Alzuguir Azevedo, Ângela Ourivio Nieckele, Aristarco Gonçalves Siqueira-Filho, Glaucia Maria Moraes de Oliveira
Background: Due to the nature of the percutaneous prosthesis deployment process, a variation in its final position is expected. Prosthetic valve placement will define the spatial location of its effective orifice in relation to the aortic annulus. The blood flow pattern in the ascending aorta is related to the aortic remodeling process, and depends on the spatial location of the effective orifice. The hemodynamic effect of small variations in the angle of inclination of the effective orifice has not been studied in detail...
August 7, 2017: Arquivos Brasileiros de Cardiologia
https://www.readbyqxmd.com/read/28764326/comprehensive-study-of-the-flow-control-strategy-in-a-wirelessly-charged-centrifugal-microfluidic-platform-with-two-rotation-axes
#4
Yunzeng Zhu, Yiqi Chen, Xiangrui Meng, Jing Wang, Ying Lu, Youchun Xu, Jing Cheng
Centrifugal microfluidics has been widely applied in the sample-in-answer-out systems for the analyses of nucleic acids, proteins, and small molecules. However, the inherent characteristic of unidirectional fluid propulsion limits the flexibility of these fluidic chips. Providing an extra degree of freedom to allow the unconstrained and reversible pumping of liquid is an effective strategy to address this limitation. In this study, a wirelessly charged centrifugal microfluidic platform with two rotation axes has been constructed and the flow control strategy in such platform with two degrees of freedom was comprehensively studied for the first time...
August 14, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28741093/fetal-right-ventricular-prominence-associated-postnatal-abnormalities-and-coarctation-clinical-prediction-tool
#5
Alyssa Power, Alberto Nettel-Aguirre, Deborah Fruitman
Fetal right ventricular (RV) prominence is a known indicator of possible left-sided structural heart disease with a low positive predictive value for aortic coarctation. There is a paucity of data on identifying which fetuses with RV prominence will have postnatal arch obstruction. Our study objectives were to create a clinical prediction tool for coarctation and to describe the diagnostic outcomes of our cohort with fetal RV prominence. We performed a retrospective review of patients referred with fetal RV prominence from January 2009 to October 2015...
July 24, 2017: Pediatric Cardiology
https://www.readbyqxmd.com/read/28708210/particle-image-velocimetry-tests-on-pediatric-45-cc-and-30-cc-ventricle-assist-devices-effects-of-heart-rate-on-vad-operation
#6
Dariusz Witkowski, Damian Obidowski, Piotr Reorowicz, Daniel Jodko, Krzysztof Jozwik
BACKGROUND: This study investigated flow analysis inside pediatric ventricle assist devices (VADs) designed and manufactured at the Foundation for Cardiac Surgery Development (FRK), Zabrze, Poland. The main goal of the experiment was to define the minimal heart rate admissible in clinical practice. METHODS: The flow was directed by mechanical, single-disc valves developed at the Lodz University of Technology, Institute of Turbomachinery in Lodz, Poland. VAD operation conditions under different heart rates were analyzed...
July 8, 2017: International Journal of Artificial Organs
https://www.readbyqxmd.com/read/28694784/4d-flow-analysis-of-bav-related-fluid-dynamic-alterations-evidences-of-wall-shear-stress-alterations-in-absence-of-clinically-relevant-aortic-anatomical-remodeling
#7
Filippo Piatti, Francesco Sturla, Malenka M Bissell, Selene Pirola, Massimo Lombardi, Igor Nesteruk, Alessandro Della Corte, Alberto C L Redaelli, Emiliano Votta
Bicuspid aortic valve (BAV) is the most common congenital cardiac disease and is a foremost risk factor for aortopathies. Despite the genetic basis of BAV and of the associated aortopathies, BAV-related alterations in aortic fluid-dynamics, and particularly in wall shear stresses (WSSs), likely play a role in the progression of aortopathy, and may contribute to its pathogenesis. To test whether WSS may trigger aortopathy, in this study we used 4D Flow sequences of phase-contrast cardiac magnetic resonance imaging (CMR) to quantitatively compare the in vivo fluid dynamics in the thoracic aorta of two groups of subjects: (i) five prospectively enrolled young patients with normo-functional BAV and with no aortic dilation and (ii) ten age-matched healthy volunteers...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28681601/autonomous-control-of-fluids-in-a-wide-surface-tension-range-in-microfluidics
#8
Peng Ge, Shuli Wang, Yongshun Liu, Wendong Liu, Nianzuo Yu, Jianglei Zhang, Huaizhong Shen, Junhu Zhang, Bai Yang
In this paper, we report the preparation of anisotropic wetting surfaces that could control various wetting behaviors of liquids in a wide surface tension range (from water to oil), which could be employed as a platform for controlling the flow of liquids in microfluidics (MFs). The anisotropic wetting surfaces are chemistry-asymmetric "Janus" silicon cylinder arrays, which are fabricated via selecting and regulating the functional groups on the surface of each cylinder unit. Liquids (in a wide surface tension range) wet in a unidirectional manner along the direction that was modified by the group with large surface energy...
July 17, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28658639/experimental-evaluation-and-analysis-of-methane-fire-and-explosion-mitigation-using-isolation-valves-integrated-with-a-vent-system
#9
Mohammed J Ajrash, Jafar Zanganeh, Behdad Moghtaderi
There has been a surge of interest from the extractive industries in the application of mechanical means to the mitigation of flame deflagration. To verify the implementation and performance of passive and active mitigation protection, a comprehensive experimental investigation has been conducted on a large scale detonation tube, 30m long and 0.5m in diameter, with two mitigation valves (passive and active) and a burst panel venting system. The valves were used alternately to mitigate the flame deflagration of methane in concentrations ranging from 1...
June 20, 2017: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/28643891/direct-comparison-of-high-temporal-resolution-cine-mri-with-doppler-ultrasound-for-assessment-of-diastolic-dysfunction-in-mice
#10
Thomas A Roberts, Anthony N Price, Laurence H Jackson, Valerie Taylor, Anna L David, Mark F Lythgoe, Daniel J Stuckey
Diastolic dysfunction is a sensitive early indicator of heart failure and can provide additional data to conventional measures of systolic function. Transmitral Doppler ultrasound, which measures the one-dimensional flow of blood through the mitral valve, is currently the preferred method for the measurement of diastolic function, but the measurement of the left ventricular volume changes using high-temporal-resolution cinematic magnetic resonance imaging (CINE MRI) is an alternative approach which is emerging as a potentially more robust and user-independent technique...
June 23, 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/28620766/phenotype-transformation-of-aortic-valve-interstitial-cells-due-to-applied-shear-stresses-within-a-microfluidic-chip
#11
Xinmei Wang, Joohyung Lee, Mir Ali, Jungkyu Kim, Carla M R Lacerda
Despite valvular heart diseases constituting a significant medical problem, the acquisition of information describing their pathophysiology remains difficult. Due to valvular size, role and location within the body, there is a need for in vitro systems that can recapitulate disease onset and progression. This study combines the development of an in vitro model and its application in the mechanical stimulation of valvular cell transformation. Specifically, porcine aortic valvular interstitial cells (PAVIC) were cultured on polydimethylsiloxane microfluidic devices with or without exposure to shear stresses...
June 15, 2017: Annals of Biomedical Engineering
https://www.readbyqxmd.com/read/28599851/experimental-evaluation-of-control-performance-of-mpc-as-a-regulatory-controller
#12
Mohammad Khan, Malik Tahiyat, Syed Imtiaz, M A A Shoukat Choudhury, Faisal Khan
Proportional-integral-derivative (PID) control is widely practised as the base layer controller in the industry due to its robustness and design simplicity. However, a supervisory control layer over the base layer, namely a model predictive controller (MPC), is becoming increasingly popular with the advent of computer process control. The use of a supervisory layer has led to different control structures. In this study, we perform an objective investigation of several commonly used control structures such as 'Cascaded PI controller', 'DMC cascaded to PI' and 'Direct DMC'...
June 6, 2017: ISA Transactions
https://www.readbyqxmd.com/read/28593469/a-patient-specific-aortic-valve-model-based-on-moving-resistive-immersed-implicit-surfaces
#13
Marco Fedele, Elena Faggiano, Luca Dedè, Alfio Quarteroni
In this paper, we propose a full computational framework to simulate the hemodynamics in the aorta including the valve. Closed and open valve surfaces, as well as the lumen aorta, are reconstructed directly from medical images using new ad hoc algorithms, allowing a patient-specific simulation. The fluid dynamics problem that accounts from the movement of the valve is solved by a new 3D-0D fluid-structure interaction model in which the valve surface is implicitly represented through level set functions, yielding, in the Navier-Stokes equations, a resistive penalization term enforcing the blood to adhere to the valve leaflets...
June 7, 2017: Biomechanics and Modeling in Mechanobiology
https://www.readbyqxmd.com/read/28540067/utility-of-cardiac-magnetic-resonance-for-evaluation-of-mitral-regurgitation-prior-to-mitral-valve-surgery
#14
REVIEW
Neil K Mehta, Jiwon Kim, Jonathan Y Siden, Sara Rodriguez-Diego, Javid Alakbarli, Antonino Di Franco, Jonathan W Weinsaft
Mitral regurgitation (MR) is a common cause of morbidity worldwide and an accepted indication for interventional therapies which aim to reduce or resolve adverse clinical outcomes associated with MR. Cardiac magnetic resonance (CMR) provides highly accurate means of assessing MR, including a variety of approaches that can measure MR based on quantitative flow. Additionally, CMR is widely accepted as a reference standard for cardiac chamber quantification, enabling reliable detection of subtle changes in cardiac chamber size and function so as to guide decision-making regarding timing of mitral valve directed therapies...
April 2017: Journal of Thoracic Disease
https://www.readbyqxmd.com/read/28517046/three-dimensional-proximal-flow-convergence-automatic-calculation-for-determining-mitral-valve-area-in-rheumatic-mitral-stenosis
#15
Francisco Sampaio, Ricardo Ladeiras-Lopes, João Almeida, Paulo Fonseca, Ricardo Fontes-Carvalho, José Ribeiro, Vasco Gama
PURPOSE: Management of patients with mitral stenosis (MS) depends heavily on the accurate quantification of mitral valve area (MVA) using echocardiography. All currently used two-dimensional (2D) methods have limitations. Estimation of MVA using the proximal isovelocity surface area (PISA) method with real time three-dimensional (3D) echocardiography may circumvent those limitations. We aimed to evaluate the accuracy of 3D direct measurement of PISA in the estimation of MVA. METHODS: Twenty-seven consecutive patients (median age of 63 years; 77...
May 18, 2017: Echocardiography
https://www.readbyqxmd.com/read/28465035/high-pressure-liquid-chromatography-with-direct-injection-of-gas-sample
#16
Anton I Astanin, Grigory I Baram
The conventional method of using liquid chromatography to determine the composition of a gaseous mixture entails dissolving vapors in a suitable solvent, then obtaining a chromatograph of the resulting solution. We studied the direct introduction of a gaseous sample into a C18 reversed-phase column, followed by separation of the components by HPLC with UV detection. Since the chromatography was performed at high pressure, vapors readily dissolved in the eluent and the substances separated in the column as effectively as in liquid samples...
April 23, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28460569/neurological-outcome-and-frequency-of-overdrainage-in-normal-pressure-hydrocephalus-directly-correlates-with-implanted-ventriculo-peritoneal-shunt-valve-type
#17
Yavor Bozhkov, Karl Roessler, Nirjhar Hore, Michael Buchfelder, Sebastian Brandner
BACKGROUND: The correlation between neurological outcome and frequency of overdrainage in the management of idiopathic normal pressure hydrocephalus (iNPH) using different ventriculoperitoneal shunt valve types is under investigation. Thus, we retrospectively compared one group of iNPH patients implanted with a programmable differential pressure valve (DPV) with another group treated by implantation of a DPV in combination with a flow-regulated anti-siphon device valve (ASD). METHODS: A retrospective evaluation of clinical outcome and frequency of overdrainage of 40 consecutive iNPH patients following surgical management between 08/2010 and 08/2014 was performed...
May 1, 2017: Neurological Research
https://www.readbyqxmd.com/read/28450039/characterization-of-chronic-aortic-and-mitral-regurgitation-undergoing-valve-surgery-using-cardiovascular-magnetic-resonance
#18
Christian L Polte, Sinsia A Gao, Åse A Johnsson, Kerstin M Lagerstrand, Odd Bech-Hanssen
Grading of chronic aortic regurgitation (AR) and mitral regurgitation (MR) by cardiovascular magnetic resonance (CMR) is currently based on thresholds, which are neither modality nor quantification method specific. Accordingly, this study sought to identify CMR-specific and quantification method-specific thresholds for regurgitant volumes (RVols), RVol indexes, and regurgitant fractions (RFs), which denote severe chronic AR or MR with an indication for surgery. The study comprised patients with moderate and severe chronic AR (n = 38) and MR (n = 40)...
June 15, 2017: American Journal of Cardiology
https://www.readbyqxmd.com/read/28427597/intentional-percutaneous-laceration-of%C3%A2-the%C3%A2-anterior-mitral-leaflet-to-prevent%C3%A2-outflow%C3%A2-obstruction-during-transcatheter-mitral-valve-replacement-first-in-human%C3%A2-experience
#19
Vasilis C Babaliaros, Adam B Greenbaum, Jaffar M Khan, Toby Rogers, Dee Dee Wang, Marvin H Eng, William W O'Neill, Gaetano Paone, Vinod H Thourani, Stamatios Lerakis, Dennis W Kim, Marcus Y Chen, Robert J Lederman
OBJECTIVES: This study sought to use a new catheter technique to split the anterior mitral valve leaflet (AML) and prevent iatrogenic left ventricular outflow tract (LVOT) obstruction immediately before transcatheter mitral valve replacement (TMVR). BACKGROUND: LVOT obstruction is a life-threatening complication of TMVR, caused by septal displacement of the AML. METHODS: The procedure was used in patients with severe mitral valve disease and prohibitive surgical risk...
April 24, 2017: JACC. Cardiovascular Interventions
https://www.readbyqxmd.com/read/28424229/tension-activated-channels-in-the-mechanism-of-osmotic-fitness-in-pseudomonas-aeruginosa
#20
Uğur Çetiner, Ian Rowe, Anthony Schams, Christina Mayhew, Deanna Rubin, Andriy Anishkin, Sergei Sukharev
Pseudomonas aeruginosa (PA) is an opportunistic pathogen with an exceptional ability to adapt to a range of environments. Part of its adaptive potential is the ability to survive drastic osmolarity changes. Upon a sudden dilution of external medium, such as during exposure to rain, bacteria evade mechanical rupture by engaging tension-activated channels that act as osmolyte release valves. In this study, we compare fast osmotic permeability responses in suspensions of wild-type PA and Escherichia coli (EC) strains in stopped-flow experiments and provide electrophysiological descriptions of osmotic-release channels in PA...
May 1, 2017: Journal of General Physiology
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