keyword
MENU ▼
Read by QxMD icon Read
search

Atria

keyword
https://www.readbyqxmd.com/read/27909967/selective-blockade-of-%C3%AE-2-adrenoceptor-subtypes-modulates-contractility-of-rat-myocardium
#1
T L Zefirov, L I Khisamieva, N I Ziyatdinova, A L Zefirov
The study examined the dose-dependent effects of selective antagonists of α2A/D-, α2B-, and α2C- adrenoceptors applied in concentrations of 10(-9)-10(-5) M on atrial and ventricular contractility of rat myocardium in vitro. Selective blockade of each α2-adrenoceptor subtype affected the contractile force of the atrial and ventricular strips. Various concentrations of α2A/D- and α2C-adrenoceptor antagonists produced positive inotropic effect on ventricular strips and negative effect on atrial strips. α2B-Adrenoceptor blocker in the majority of the tested concentrations produced a positive inotropic effect in both atria and ventricles...
December 2, 2016: Bulletin of Experimental Biology and Medicine
https://www.readbyqxmd.com/read/27907007/exploring-regulatory-mechanisms-of-atrial-myocyte-hypertrophy-of-mitral-regurgitation-through-gene-expression-profiling-analysis-role-of-nfat-in-cardiac-hypertrophy
#2
Tzu-Hao Chang, Mien-Cheng Chen, Jen-Ping Chang, Hsien-Da Huang, Wan-Chun Ho, Yu-Sheng Lin, Kuo-Li Pan, Yao-Kuang Huang, Wen-Hao Liu, Chia-Chen Wu
BACKGROUND: Left atrial enlargement in mitral regurgitation (MR) predicts a poor prognosis. The regulatory mechanisms of atrial myocyte hypertrophy of MR patients remain unknown. METHODS AND RESULTS: This study comprised 14 patients with MR, 7 patients with aortic valve disease (AVD), and 6 purchased samples from normal subjects (NC). We used microarrays, enrichment analysis and quantitative RT-PCR to study the gene expression profiles in the left atria. Microarray results showed that 112 genes were differentially up-regulated and 132 genes were differentially down-regulated in the left atria between MR patients and NC...
2016: PloS One
https://www.readbyqxmd.com/read/27905214/the-association-of-plasma-oxidative-status-and-inflammation-with-the-development-of-atrial-fibrillation-in-patients-presenting-with-st-elevation-myocardial-infarction
#3
Hasan Aydin Bas, Fatih Aksoy, Atilla Icli, Ercan Varol, Abdullah Dogan, Dogan Erdogan, Ibrahim Ersoy, Akif Arslan, Hatem Ari, Nihal Bas, Recep Sutcu, Mehmet Ozaydin
Atrial fibrillation (AF) is the most common supraventricular arrhythmia following ST elevation myocardial infarction (STEMI). Oxidative stress and inflammation may cause structural and electrical remodeling in the atria making these critical processes in the pathology of AF. In this study, we aimed to evaluate the association between total oxidative status (TOS), total antioxidative capacity (TAC) and high-sensitivity C-reactive protein (hs-CRP) in the development of AF in patients presenting with STEMI. This prospective cohort study consisted of 346 patients with STEMI...
December 1, 2016: Scandinavian Journal of Clinical and Laboratory Investigation
https://www.readbyqxmd.com/read/27884747/novel-function-of-%C3%AE-1d-l-type-calcium-channel-in-the-atria
#4
Ujala Srivastava, Ademuyiwa S Aromolaran, Frank Fabris, Deana Lazaro, John Kassotis, Yongxia Qu, Mohamed Boutjdir
Ca entry through atrial L-type Calcium channels (α1C and α1D) play an important role in muscular contraction, regulation of gene expression, and release of hormones including atrial natriuretic peptide (ANP), and brain natriuretic peptide (BNP). α1D Ca channel is exclusively expressed in atria, and has been shown to play a key role in the pathogenesis of atrial fibrillation. Recent data have shown that the small conductance calcium-activated potassium channel, SK4 is also atrial specific and also contributes prominently to the secretion of ANP and BNP...
November 22, 2016: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/27882143/expression-of-connexin-43-ion-channels-and-ca-2-handling-proteins-in-rat-pulmonary-vein-cardiomyocytes
#5
Yaqiong Xiao, Xue Cai, Andrew Atkinson, Sunil Jit Logantha, Mark Boyett, Halina Dobrzynski
Atrial fibrillation (AF) is the most common cardiac arrhythmia. AF is thought to be triggered by ectopic beats, originating primarily in the myocardial sleeves surrounding the pulmonary veins (PVs). The mechanisms underlying these cardiac arrhythmias remain unclear. To investigate this, frozen sections of heart and lung tissue from adult rats without arrhythmia were obtained in different planes, stained with Masson's trichrome, and immunolabeled for connexin 43 (Cx43), caveolin-3 (Cav3), hyperpolarization-activated cyclic nucleotide-gated channel 4 (HCN4), Nav1...
November 2016: Experimental and Therapeutic Medicine
https://www.readbyqxmd.com/read/27878421/the-role-of-the-atrial-electromechanical-delay-in-predicting-atrial-fibrillation-in-beta-thalassemia-major-patients
#6
Anna Rago, Vincenzo Russo, Andrea Antonio Papa, Carmine Ciardiello, Bruno Pannone, Maria Carolina Mayer, Giovanni Cimmino, Gerardo Nigro
BACKGROUND: Paroxysmal atrial tachyarrhythmias frequently occur in beta-thalassemia major (β-TM) patients. The aim of the current study was to evaluate the atrial electromechanical delay (AEMD) in a large β-TM population with normal cardiac function and its relationship to atrial fibrillation (AF) onset. METHODS: Eighty β-TM patients (44 men, 36 women), with a mean age of 36.2 ± 11.1 years, and 80 healthy subjects used as controls, matched for age and gender, were studied for the occurrence of AF during a 5-year follow-up, through 30-day external loop recorder (ELR) monitoring performed every 6 months...
November 22, 2016: Journal of Interventional Cardiac Electrophysiology: An International Journal of Arrhythmias and Pacing
https://www.readbyqxmd.com/read/27875900/effects-of-necrostatin-1-an-inhibitor-of-necroptosis-and-its-inactive-analogue-nec-1i-on-basal-cardiovascular-function
#7
A Szobi, T Rajtik, A Adameova
Inhibition of receptor-interacting serine/threonine-protein kinase 1 (RIP1) by necrostatin-1 (Nec-1) alleviates cardiac injury due to prevention of necroptotic cell death. Its inactive analogue necrostatin-1i (Nec-1i), lacking RIP1 activity, serves as a suitable control. It is unknown if these agents influence the heart function in the absence of damaging stimuli. For this purpose, we measured intraarterial blood pressure (systolic - sBP and diastolic - dBP) and ECG parameters after a bolus administration of Nec-1 and Nec-1i in rats during 30 min...
November 23, 2016: Physiological Research
https://www.readbyqxmd.com/read/27875722/progenitor-cells-from-atria-ventricle-and-peripheral-blood-of-the-same-patients-exhibit-functional-differences-associated-with-cardiac-repair
#8
Parul Dixit, Hayden Donnelly, Midori Edamatsu, Ivor Galvin, Richard Bunton, Rajesh Katare
AIM: Deciding the best cell type for cardiac regeneration remains a big challenge. No studies have directly compared the functional efficacy of cardiac progenitor cells (CPCs) with extra-cardiac stem cells isolated from the same patient. METHODS AND RESULTS: We compared the functional characteristics of endothelial progenitor cells (EPCs), right atrial (RAA) CPCs and left ventricular (LV) CPCs isolated from the same patients (n=14). Within the same heart, RAA and LV CPCs exhibited marked differences in surface marker expression, with RAA CPCs exhibiting better expansion potential and migration properties...
November 19, 2016: International Journal of Cardiology
https://www.readbyqxmd.com/read/27875591/reentry-and-ectopic-pacemakers-emerge-in-a-three-dimensional-model-for-a-slab-of-cardiac-tissue-with-diffuse-microfibrosis-near-the-percolation-threshold
#9
Sergio Alonso, Rodrigo Weber Dos Santos, Markus Bär
Arrhythmias in cardiac tissue are generally associated with irregular electrical wave propagation in the heart. Cardiac tissue is formed by a discrete cell network, which is often heterogeneous. Recently, it was shown in simulations of two-dimensional (2D) discrete models of cardiac tissue that a wave crossing a fibrotic, heterogeneous region may produce reentry and transient or persistent ectopic activity provided the fraction of conducting connections is just above the percolation threshold. Here, we investigate the occurrence of these phenomena in three-dimensions by simulations of a discrete model representing a thin slab of cardiac tissue...
2016: PloS One
https://www.readbyqxmd.com/read/27863381/probucol-prevents-atrial-ion-channel-remodeling-in-an-alloxan-induced-diabetes-rabbit-model
#10
Huaying Fu, Guangping Li, Changle Liu, Jian Li, Lijun Cheng, Wansong Yang, Gary Tse, Jichao Zhao, Tong Liu
Diabetes mellitus (DM) increases the risk of developing atrial fibrillation (AF), but the molecular mechanisms of diabetes-induced atrial remodeling processes have not been fully characterized. The aim of this study was to examine the mechanisms underlying atrial ion channel remodeling in alloxan-induced diabetes model in rabbits. A total of 40 Japanese rabbits were randomly assigned to a control group (C), alloxan-induced diabetic group (DM), probucol-treated control group (Control-P), and probucol-treated diabetic group (DM-P)...
November 14, 2016: Oncotarget
https://www.readbyqxmd.com/read/27862058/translation-of-first-north-american-50-and-70-cc-total-artificial-heart-virtual-and-clinical-implantations-utility-of-3d-computed-tomography-to-test-fit-devices
#11
Alice S Ferng, Isabel Oliva, Clinton Jokerst, Ryan Avery, Alana M Connell, Phat L Tran, Richard G Smith, Zain Khalpey
Since the creation of SynCardia's 50 cc Total Artificial Hearts (TAHs), patients with irreversible biventricular failure now have two sizing options. Herein, a case series of three patients who have undergone successful 50 and 70 cc TAH implantation with complete closure of the chest cavity utilizing preoperative "virtual implantation" of different sized devices for surgical planning are presented. Computed tomography (CT) images were used for preoperative planning prior to TAH implantation. Three-dimensional (3D) reconstructions of preoperative chest CT images were generated and both 50 and 70 cc TAHs were virtually implanted into patients' thoracic cavities...
November 10, 2016: Artificial Organs
https://www.readbyqxmd.com/read/27829827/the-prognostic-value-of-using-ultrasonography-in-cardiac-resuscitation-of-patients-with-cardiac-arrest
#12
Ehsan Bolvardi, Seyyed Mohsen Pouryaghobi, Roohye Farzane, Niaz Mohamad Jafari Chokan, Koorosh Ahmadi, Hamidreza Reihani
Cardiopulmonary arrest is the final result of many diseases and therefore, need for a careful implementation of cardiopulmonary resuscitation (CPR) protocols in these cases is undeniably important. The introduction of ultrasound into the emergency department has potentially allowed the addition of an extra data point in the decision about when to cease cardiopulmonary resuscitation (CPR). The aim of this study is to evaluate the ability of cardiac ultrasonography performed by emergency physicians to predict resuscitation outcome in adult cardiac arrest patients...
September 2016: International Journal of Biomedical Science: IJBS
https://www.readbyqxmd.com/read/27826248/slow-conduction-in-the-border-zones-of-patchy-fibrosis-stabilizes-the-drivers-for-atrial-fibrillation-insights-from-multi-scale-human-atrial-modeling
#13
Ross Morgan, Michael A Colman, Henry Chubb, Gunnar Seemann, Oleg V Aslanidi
Introduction: The genesis of atrial fibrillation (AF) and success of AF ablation therapy have been strongly linked with atrial fibrosis. Increasing evidence suggests that patient-specific distributions of fibrosis may determine the locations of electrical drivers (rotors) sustaining AF, but the underlying mechanisms are incompletely understood. This study aims to elucidate a missing mechanistic link between patient-specific fibrosis distributions and AF drivers. Methods: 3D atrial models integrated human atrial geometry, rule-based fiber orientation, region-specific electrophysiology, and AF-induced ionic remodeling...
2016: Frontiers in Physiology
https://www.readbyqxmd.com/read/27823686/how-well-does-physician-risk-assessment-predict-stroke-and-bleeding-in-atrial-fibrillation-results-from-the-outcomes-registry-for-better-informed-treatment-of-atrial-fibrillation-orbit-af
#14
Benjamin A Steinberg, Peter Shrader, Sunghee Kim, Laine Thomas, Gregg C Fonarow, Jack Ansell, Peter R Kowey, Daniel E Singer, Bernard J Gersh, Kenneth W Mahaffey, Eric D Peterson, Jonathan P Piccini
BACKGROUND: Assessments of stroke and bleeding risks are essential to selecting oral anticoagulation in patients with atrial fibrillation (AF). We aimed to assess outcomes according to physician assessed risk, with comparison to empirical risk scores. METHODS: This was a prospective, observational study of 9,715 outpatients with AF enrolled in ORBIT-AF, a US national registry. Stroke and bleeding risks were quantified by physician assignment, CHADS2 and CHA2DS2-VASc stroke scores, and ATRIA and HAS-BLED bleeding scores...
November 2016: American Heart Journal
https://www.readbyqxmd.com/read/27818786/trpm7-is-down-regulated-in-both-left-atria-and-left-ventricle-of-ischaemic-cardiomyopathy-patients-and-highly-related-to-changes-in-ventricular-function
#15
Ana Ortega, Esther Roselló-Lletí, Estefanía Tarazón, Carolina Gil-Cayuela, Francisca Lago, Jose-Ramón González-Juanatey, Luis Martinez-Dolz, Manuel Portolés, Miguel Rivera
AIMS: The kinase ion channel transient receptor potential melastatin 7 (TRPM7) is considered a modulator of cardiac fibrosis progression; nevertheless, we lack of studies analysing its role in human ischaemic cardiomyopathy (ICM). Our objective was to analyse the expression of genes encoding cardiac ion channels in human ICM, focusing on the alterations in mRNA levels of TRPM7 and its relationship with changes in the ventricular function. METHODS AND RESULTS: RNA-sequencing was carried out in 13 left ventricular (LV) samples of patients with ICM compared with a control group (n = 10)...
September 2016: ESC Heart Failure
https://www.readbyqxmd.com/read/27812021/mechanisms-of-arrhythmogenesis-related-to-calcium-driven-alternans-in-a-model-of-human-atrial-fibrillation
#16
Kelly C Chang, Natalia A Trayanova
The occurrence of atrial fibrillation (AF) is associated with progressive changes in the calcium handling system of atrial myocytes. Calcium cycling instability has been implicated as an underlying mechanism of electrical alternans observed in patients who experience AF. However, the extent to which calcium-induced alternation of electrical activity in the atria contributes to arrhythmogenesis is unknown. In this study, we investigated the effects of calcium-driven alternans (CDA) on arrhythmia susceptibility in a biophysically detailed, 3D computer model of the human atria representing electrical and structural remodeling secondary to chronic AF...
November 4, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27801994/clinical-evaluation-of-three-dimensional-late-enhancement-mri
#17
Konstantinos Bratis, Markus Henningsson, Chrisanthos Grigoratos, Matteo Dell' Omodarme, Konstantinos Chasapides, Rene Botnar, Eike Nagel
PURPOSE: To assess the diagnostic value of three-dimensional late enhancement (3D-LGE) for the detection of myocardial necrosis in a routine clinical setting. 3D-LGE has been proposed as a novel magnetic resonance (MR) technique for the accurate detection of myocardial scar in both the ventricles and atria. Its performance in clinical practice has been poorly examined. MATERIALS AND METHODS: Fifty-seven patients referred for cardiac MR examination including scar imaging were prospectively enrolled...
November 1, 2016: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/27796891/cardiac-telocytes-in-regeneration-of-myocardium-after-myocardial-infarction
#18
Liao Zhaofu, Cai Dongqing
Recent research progress has revealed that a novel type of interstitial cells termed cardiac telocytes (CTs) is found in the interstitium of the heart. We demonstrated that CTs are distributed both longitudinally and within the cross network in the myocardium and that the density of CTs in the atrium-atria and base of the myocardium is higher than that in the middle of the myocardium, while the density of CTs in the epicardium is higher than that in the endocardium. In addition, we documented, for the first time, that the network of CTs in the infarct zone of the myocardium is destroyed during myocardial infarction (MI)...
2016: Advances in Experimental Medicine and Biology
https://www.readbyqxmd.com/read/27790158/regularization-techniques-for-ecg-imaging-during-atrial-fibrillation-a-computational-study
#19
Carlos Figuera, Víctor Suárez-Gutiérrez, Ismael Hernández-Romero, Miguel Rodrigo, Alejandro Liberos, Felipe Atienza, María S Guillem, Óscar Barquero-Pérez, Andreu M Climent, Felipe Alonso-Atienza
The inverse problem of electrocardiography is usually analyzed during stationary rhythms. However, the performance of the regularization methods under fibrillatory conditions has not been fully studied. In this work, we assessed different regularization techniques during atrial fibrillation (AF) for estimating four target parameters, namely, epicardial potentials, dominant frequency (DF), phase maps, and singularity point (SP) location. We use a realistic mathematical model of atria and torso anatomy with three different electrical activity patterns (i...
2016: Frontiers in Physiology
https://www.readbyqxmd.com/read/27785831/multimodality-imaging-evaluation-of-a-mitro-aortic-fibrosa-pseudoaneurysm-fistulizing-into-both-atria
#20
Jose David Arroja, Anne Lise Hachulla, Christoph Ellenberger, Hajo Müller
To our knowledge, we describe the first case of a pseudoaneurysm of the mitro-aortic intervalvular fibrosa fistulizing into both atria, following an aortic bacterial endocarditis and valve replacement.
October 27, 2016: Echocardiography
keyword
keyword
94147
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"