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https://www.readbyqxmd.com/read/28985746/porcine-model-of-progressive-cardiac-hypertrophy-and-fibrosis-with-secondary-postcapillary-pulmonary-hypertension
#1
Mariann Gyöngyösi, Noemi Pavo, Dominika Lukovic, Katrin Zlabinger, Andreas Spannbauer, Denise Traxler, Georg Goliasch, Ljubica Mandic, Jutta Bergler-Klein, Alfred Gugerell, Andras Jakab, Zsuzsanna Szankai, Levente Toth, Rita Garamvölgyi, Gerald Maurer, Frederic Jaisser, Faiez Zannad, Thomas Thum, Sándor Bátkai, Johannes Winkler
BACKGROUND: Meaningful translational large animal models for cardiac diseases are indispensable for studying disease mechanisms, development of novel therapeutic strategies, and evaluation of potential drugs. METHODS: For induction of heart failure, cardiac hypertrophy and fibrosis, a bare metal stent was implanted in the descending aorta of growing pigs (n = 7), inducing pressure stress on the left ventricle (group HYPI). The constant stent size in growing pigs resulted in antegrade partial obstruction of the aortic flow with a gradual increase in afterload...
October 6, 2017: Journal of Translational Medicine
https://www.readbyqxmd.com/read/28979698/stachydrine-ameliorates-pressure-overload-induced-diastolic-heart-failure-by-suppressing-myocardial-fibrosis
#2
Hui-Hua Chen, Pei Zhao, Wen-Xia Zhao, Jing Tian, Wei Guo, Ming Xu, Chen Zhang, Rong Lu
Stachydrine (Sta), a major constituent of Leonurus japonicus Houtt, has been reported to possess numerous cardioprotective effects. In this study, we evaluated the effect of Sta on pressure overload-induced diastolic heart failure in rats and investigated the mechanisms underlying the effect. Wistar rats were randomized to transverse aortic constriction (TAC) or sham operation. After 3 days, the rats that underwent TAC were randomized to treatment for a total of four experimental groups (n=10 each group): sham operation, TAC only, TAC + telmisartan (Tel), and TAC + stachydrine (Sta)...
2017: American Journal of Translational Research
https://www.readbyqxmd.com/read/28961240/myocardial-wall-stiffening-in-a-mouse-model-of-persistent-truncus-arteriosus
#3
Christine Miller Buffinton, Alyssa K Benjamin, Ashley N Firment, Anne M Moon
BACKGROUND: Genetic and epigenetic programs regulate dramatic structural changes during cardiac morphogenesis. Concurrent biomechanical forces within the heart created by blood flow and pressure in turn drive downstream cellular, molecular and genetic responses. Thus, a genetic-morphogenetic-biomechanical feedback loop is continually operating to regulate heart development. During the evolution of a congenital heart defect, concomitant abnormalities in blood flow, hemodynamics, and patterns of mechanical loading would be predicted to change the output of this feedback loop, impacting not only the ultimate morphology of the defect, but potentially altering tissue-level biomechanical properties of structures that appear structurally normal...
2017: PloS One
https://www.readbyqxmd.com/read/28954293/role-of-myocardial-constructive-work-in-the-identification-of-responders-to-crt
#4
Elena Galli, Christophe Leclercq, Arnaud Hubert, Anne Bernard, Otto A Smiseth, Philippe Mabo, Eigil Samset, Alfredo Hernandez, Erwan Donal
Aims: Cardiac resynchronization therapy (CRT) plays a pivotal role in the management of patients with heart failure (HF) and wide QRS complex. However, the treatment is plagued by numerous non-responders. Aim of the study is to evaluate the role myocardial work estimated by pressure-strain loops (PSLs) in the comprehension of physiological mechanisms associated with CRT and in the prediction of CRT response. Methods and results: Ninety-seven patients with symptomatic HF (ejection fraction: 27 ± 6%, QRS duration 164 ± 18 ms) undergoing CRT implantation according to current recommendations were retrospectively included in the study...
August 7, 2017: European Heart Journal Cardiovascular Imaging
https://www.readbyqxmd.com/read/28874820/image-based-closed-loop-feedback-for-highly-mono-dispersed-microdroplet-production
#5
D F Crawford, C A Smith, G Whyte
Micron-scale droplets isolated by an immiscible liquid can provide miniaturised reaction vessels which can be manipulated in microfluidic networks, and has seen a rapid growth in development. In many experiments, the precise volume of these microdroplets is a critical parameter which can be influenced by many external factors. In this work, we demonstrate the combination of imaging-based feedback and pressure driven pumping to accurately control the size of microdroplets produced in a microfluidic device. The use of fast-response, pressure-driving pumps allows the microfluidic flow to be quickly and accurately changed, while directly measuring the droplet size allows the user to define the more meaningful parameters of droplet size and generation frequency rather than flow rates or pressures...
September 5, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28874030/synergistic-effects-of-remote-perconditioning-with-terminal-blood-cardioplegia-in-an-in-vivo-piglet-model
#6
Takayuki Abe, Kiyozo Morita, Gen Shinohara, Kazuhiro Hashimoto, Masako Nishikawa
OBJECTIVES: This study tested the hypothesis that remote perconditioning offers effective and synergistic cardioprotection to terminal warm blood cardioplegia for prompt ventricular recovery after prolonged cardioplegic arrest in an in vivo piglet model. METHODS: Twenty-four piglets were subjected to 120 min of single-dose cardioplegic arrest and were divided into 4 groups according to the mode of reperfusion: control (simple aortic unclamp), remote perconditioning, terminal warm blood cardioplegia or remote perconditioning + terminal warm blood cardioplegia; remote perconditioning (4 cycles of 5-min ischaemia-reperfusion of the lower limb) was applied prior to aortic unclamping...
September 1, 2017: European Journal of Cardio-thoracic Surgery
https://www.readbyqxmd.com/read/28865801/approach-to-acute-heart-failure-in-the-emergency-department
#7
REVIEW
Benton R Hunter, Jennifer Martindale, Osama Abdel-Hafez, Peter S Pang
Acute heart failure (AHF) patients rarely present complaining of 'acute heart failure.' Rather, they initially present to the emergency department (ED) with a myriad of chief complaints, symptoms, and physical exam findings. Such heterogeneity prompts an initially broad differential diagnosis; securing the correct diagnosis can be challenging. Although AHF may be the ultimate diagnosis, the precipitant of decompensation must also be sought and addressed. For those AHF patients who present in respiratory or circulatory failure requiring immediate stabilization, treatment begins even while the diagnosis is uncertain...
September 2017: Progress in Cardiovascular Diseases
https://www.readbyqxmd.com/read/28864183/novel-volumetric-method-for-highly-repeatable-injection-in-microchip-electrophoresis
#8
Noel S Ha, Jimmy Ly, Jason Jones, Shilin Cheung, R Michael van Dam
A novel injector for microchip electrophoresis (MCE) has been designed and evaluated that achieves very high repeatability of injection volume suitable for quantitative analysis. It eliminates the injection biases in electrokinetic injection and the dependence on pressure and sample properties in hydrodynamic injection. The microfluidic injector, made of poly(dimethylsiloxane) (PDMS), operates similarly to an HPLC injection valve. It contains a channel segment (chamber) with a well-defined volume that serves as an "injection loop"...
September 8, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28862717/an-original-valveless-artificial-heart-providing-pulsatile-flow-tested-in-mock-circulatory-loops
#9
Piergiorgio Tozzi, Audrey Maertens, Jonathan Emery, Samuel Joseph, Matthias Kirsch, François Avellan
PURPOSE: We present the test bench results of a valveless total artificial heart that is potentially compatible with the pediatric population. METHODS: The RollingHeart is a valveless volumetric pump generating pulsatile flow. It consists of a single spherical cavity divided into 4 chambers by 2 rotating disks. The combined rotations of both disks produce changes in the volumes of the 4 cavities (suction and ejection). The blood enters/exits the spherical cavity through 4 openings that are symmetrical to the fixed rotation axis of the first disk...
August 11, 2017: International Journal of Artificial Organs
https://www.readbyqxmd.com/read/28841117/transient-resolution-of-venous-sinus-stenosis-after-high-volume-lumbar-puncture-in-a-patient-with-idiopathic-intracranial-hypertension
#10
Thomas J Buell, Daniel M S Raper, I Jonathan Pomeraniec, Dale Ding, Ching-Jen Chen, Davis G Taylor, Kenneth C Liu
Stenosis of the transverse sinus (TS) and sigmoid sinus (SS), with a trans-stenosis pressure gradient, has been implicated in the pathophysiology of idiopathic intracranial hypertension (IIH). MRI has shown improvement in TS and SS stenosis after high-volume lumbar puncture (HVLP) in a subset of patients with IIH. The authors present the first report of an IIH patient with immediate post-HVLP TS and SS trans-stenosis pressure gradient reduction and an attendant increase in TS and SS cross-sectional area confirmed using intravascular ultrasonography (IVUS)...
August 25, 2017: Journal of Neurosurgery
https://www.readbyqxmd.com/read/28829615/three-dimensional-3-d-ferromagnetic-network-of-mn12-single-molecule-magnets-subtle-environmental-effects-and-switching-to-antiferromagnetic
#11
Adeline D Fournet, Kylie J Mitchell, Wolfgang Wernsdorfer, Khalil A Abboud, George Christou
A new member of the Mn12 family of single-molecule magnets (SMMs) has been prepared and found to be the first of this family to give a 3-D ferromagnetic network. [Mn12O12(O2CC6H4-p-F)16(H2O)4] (2) was prepared by carboxylate substitution on the acetate derivative with p-F-benzoic acid and crystallizes as 2·8MeCN in space group I4̅2m with extensive formation of intermolecular C-H···F hydrogen-bonding. The latter leads to a combination of ferromagnetic (F) and antiferromagnetic (AF) interactions and an overall F network that gives a χMT value at low T that is abnormally high for an S = 10 ground state...
August 22, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28803369/volume-balance-and-intradialytic-ultrafiltration-rate-in-the-hemodialysis-patient
#12
REVIEW
Jason A Chou, Kamyar Kalantar-Zadeh
PURPOSE OF REVIEW: Volume management in hemodialysis patients is often challenging. Assessing volume status and deciding how much fluid to remove during hemodialysis, the so-called ultrafiltration rate (UFR), has remained a conundrum. RECENT FINDINGS: To date there is no objective assessment tool to determine the needed UFR during each hemodialysis session. Higher volume overload or higher UFR is associated with poor outcomes including worse mortality and unfavorable clinical outcomes...
August 12, 2017: Current Heart Failure Reports
https://www.readbyqxmd.com/read/28801076/early-development-of-right-ventricular-ischemic-lesions-in-a-novel-large-animal-model-of-acute-right-heart-failure-in-chronic-thromboembolic-pulmonary-hypertension
#13
David Boulate, Jennifer Arthur Ataam, Andrew J Connolly, Genevieve Giraldeau, Myriam Amsallem, Benoit Decante, Lilia Lamrani, Elie Fadel, Peter Dorfmuller, Frederic Perros, Francois Haddad, Olaf Mercier
BACKGROUND: Our aim was to develop a model of acute right heart failure (ARHF) in the setting of pulmonary hypertension and to characterize acute right ventricular lesions that develop early after hemodynamic restoration. METHODS AND RESULTS: We used a described piglet model of chronic pulmonary hypertension (cPH) induced by pulmonary artery occlusions. We induced ARHF in animals with cPH (ARHF-cPH group, n = 9) by volume loading and iterative acute pulmonary embolism until hemodynamic compromise followed by dobutamine infusion for hemodynamic restoration before sacrifice for right ventricular tissue evaluation...
August 8, 2017: Journal of Cardiac Failure
https://www.readbyqxmd.com/read/28752570/a-preliminary-comparison-of-two-dimensional-speckle-tracking-echocardiography-and-pressure-volume-loop-analysis-in-patients-with-fontan-physiology-the-role-of-ventricular-morphology
#14
David Steflik, Ryan J Butts, George H Baker, Varsha Bandisode, Andrew Savage, Andrew M Atz, Shahryar M Chowdhury
OBJECTIVE: Speckle tracking echocardiography (STE) may be a useful modality for assessing ventricular performance in patients with single ventricle physiology. However, STE's ability to accurately assess ventricular performance in this population is unknown. The objective of this study was to perform a preliminary comparison of STE measures of myocardial deformation to reference standard measures of function derived from pressure-volume loop (PVL) analysis. DESIGN: This was a secondary analysis of a prospective study investigating PVLs in patients with Fontan physiology...
September 2017: Echocardiography
https://www.readbyqxmd.com/read/28743382/preoperative-echocardiographic-measures-of-left-ventricular-mechanics-are-associated-with-postoperative-vasoactive-support-in-preterm-infants-undergoing-patent-ductus-arteriosus-ligation
#15
Margaret A Gray, Eric M Graham, Andrew M Atz, Scott M Bradley, Minoo N Kavarana, Shahryar M Chowdhury
OBJECTIVE: Preoperative risk factors associated with poor outcomes after patent ductus arteriosus ligation in preterm infants have not been well defined. The aim of this study was to determine the association between preoperative echocardiographic measures of left ventricular mechanics and postoperative clinical outcomes after patent ductus arteriosus ligation. METHODS: Preterm infants less than 90 days of age with no other significant congenital anomalies who underwent patent ductus arteriosus ligation between 2007 and 2015 were considered for retrospective analysis...
July 5, 2017: Journal of Thoracic and Cardiovascular Surgery
https://www.readbyqxmd.com/read/28741664/in-vitro-evaluation-of-an-immediate-response-starling-like-controller-for-dual-rotary-blood-pumps
#16
Andrew F Stephens, Michael C Stevens, Shaun D Gregory, Matthias Kleinheyer, Robert F Salamonsen
Rotary ventricular assist devices (VADs) are used to provide mechanical circulatory support. However, their lack of preload sensitivity in constant speed control mode (CSC) may result in ventricular suction or venous congestion. This is particularly true of biventricular support, where the native flow-balancing Starling response of both ventricles is diminished. It is possible to model the Starling response of the ventricles using cardiac output and venous return curves. With this model, we can create a Starling-like physiological controller (SLC) for VADs which can automatically balance cardiac output in the presence of perturbations to the circulation...
July 25, 2017: Artificial Organs
https://www.readbyqxmd.com/read/28711449/intrarenal-flow-alterations-during-transition-from-euvolemia-to-intravascular-volume-expansion-in-heart-failure-patients
#17
Petra Nijst, Pieter Martens, Matthias Dupont, W H Wilson Tang, Wilfried Mullens
OBJECTIVES: The goal of this study was to assess: 1) the intrarenal flow in heart failure (HF) patients during the transition from euvolemia to intravascular volume overload; and 2) the relationship between intrarenal flow and diuretic efficiency. BACKGROUND: Intrarenal blood flow alterations may help to better understand impaired volume handling in HF. METHODS: Resistance index (RI) and venous impedance index (VII) were assessed in 6 healthy subjects, 40 euvolemic HF patients with reduced ejection fraction (HFrEF) and 10 HF patients with preserved ejection fraction (HFpEF)...
July 6, 2017: JACC. Heart Failure
https://www.readbyqxmd.com/read/28708599/assessing-right-ventricular-function-in-pulmonary-hypertension-patients-and-the-correlation-with-the-new-york-heart-association-nyha-classification
#18
Xiaoke Shang, Shuna Xiao, Nianguo Dong, Rong Lu, Lijun Wang, Bin Wang, Yousan Chen, Liang Zhong, Mei Liu
This investigation aimed to compare the pressure-volume loop (PV loop) measurements in three less symptomatic categories (New York Heart Association classes , NYHA I, II, and III) of pulmonary hypertension (PH) patients since NYHA classification system performance is limited by the shortcomings discussed above.Thirty-six patients were enrolled in this study with PV loop measurement acquisition via micro-conductance catheters. Functional classification according to NYHA was determined with comprehensive assessing function and activity...
July 5, 2017: Oncotarget
https://www.readbyqxmd.com/read/28699322/a-respiratory-marker-derived-from-left-vagus-nerve-signals-recorded-with-implantable-cuff-electrodes
#19
Cristian Sevcencu, Thomas N Nielsen, Benedict Kjaergaard, Johannes J Struijk
OBJECTIVE: Left vagus nerve (LVN) stimulation (LVNS) has been tested for lowering the blood pressure (BP) in patients with resistant hypertension (RH). Whereas, closed-loop LVNS (CL-LVNS) driven by a BP marker may be superior to open-loop LVNS, there are situations (e.g., exercising) when hypertension is normal. Therefore, an ideal anti-RH CL-LVNS system requires a variable to avoid stimulation in such conditions, for example, a respiratory marker ideally extracted from the LVN. As the LVN conducts respiratory signals, this study aimed to investigate if such signals can be recorded using implantable means and if a marker to monitor respiration could be derived from such recordings...
July 11, 2017: Neuromodulation: Journal of the International Neuromodulation Society
https://www.readbyqxmd.com/read/28682837/closed-loop-and-decision-assist-guided-fluid-therapy-of-human-hemorrhage
#20
Gabriel Hundeshagen, George C Kramer, Nicole Ribeiro Marques, Michael G Salter, Aristides K Koutrouvelis, Husong Li, Daneshvari R Solanki, Alexander Indrikovs, Roger Seeton, Sheryl N Henkel, Michael P Kinsky
OBJECTIVES: We sought to evaluate the efficacy, efficiency, and physiologic consequences of automated, endpoint-directed resuscitation systems and compare them to formula-based bolus resuscitation. DESIGN: Experimental human hemorrhage and resuscitation. SETTING: Clinical research laboratory. SUBJECTS: Healthy volunteers. INTERVENTIONS: Subjects (n = 7) were subjected to hemorrhage and underwent a randomized fluid resuscitation scheme on separate visits 1) formula-based bolus resuscitation; 2) semiautonomous (decision assist) fluid administration; and 3) fully autonomous (closed loop) resuscitation...
October 2017: Critical Care Medicine
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