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https://www.readbyqxmd.com/read/28437860/chronic-inhibition-of-fatty-acid-amide-hydrolase-by-urb597-produces-differential-effects-on-cardiac-performance-in-normotensive-and-hypertensive-rats
#1
Anna Pedzinska-Betiuk, Jolanta Weresa, Marek Toczek, Marta Baranowska-Kuczko, Irena Kasacka, Ewa Harasim-Symbor, Barbara Malinowska
BACKGROUND AND PURPOSE: Fatty acid amide hydrolase (FAAH) inhibitors are postulated to possess anti-hypertensive potential, because their acute injection decreases blood pressure (BP) in spontaneously hypertensive rats (SHR) partially through normalization of cardiac contractile function. Here, we examined whether the potential hypotensive effect of chronic FAAH inhibition by URB597 in hypertensive rats correlates with changes in cardiac performance. EXPERIMENTAL APPROACH: Experiments were performed using perfused hearts and left atria isolated from 8-10 week old SHR, age-matched deoxycorticosterone acetate (DOCA-salt) rats and normotensive controls chronically treated with URB597 (1 mg kg(-1) ) or vehicle...
April 24, 2017: British Journal of Pharmacology
https://www.readbyqxmd.com/read/28427997/distinct-sequences-and-post-translational-modifications-in-cardiac-atrial-and-ventricular-myosin-light-chains-revealed-by-top-down-mass-spectrometry
#2
Zachery R Gregorich, Wenxuan Cai, Ziqing Lin, Albert J Chen, Ying Peng, Takushi Kohmoto, Ying Ge
Myosin is the principal component of the thick filaments that, through interactions with the actin thin filaments, mediates force production during muscle contraction. Myosin is a hexamer, consisting of two heavy chains, each associated with an essential (ELC) and a regulatory (RLC) light chain, which bind the lever-arm of the heavy chain and play important modulatory roles in striated muscle contraction. Nevertheless, a comprehensive assessment of the sequences of the ELC and RLC isoforms, as well as their post-translational modifications, in the heart remains lacking...
April 17, 2017: Journal of Molecular and Cellular Cardiology
https://www.readbyqxmd.com/read/28422654/novel-mri-technique-enables-non-invasive-measurement-of-atrial-wall-thickness
#3
Marta Varela, Ross Morgan, Adeline Theron, Desmond Dillon-Murphy, Henry Chubb, John Whitaker, Markus Henningsson, Paul Aljabar, Tobias Schaeffter, Christoph Kolbitsch, Oleg V Aslanidi
Knowledge of atrial wall thickness (AWT) has the potential to provide important information for patient stratification and the planning of interventions in atrial arrhythmias. To date, information about AWT has only been acquired in post-mortem or poor-contrast CT studies, providing limited coverage and highly variable estimates of AWT. We present a novel contrast agent-free MRI sequence for imaging AWT and use it to create personalized AWT maps and a biatrial atlas. A novel black-blood phase-sensitive inversion recovery protocol was used to image 10 volunteers and 2 atrial fibrillation patients, as proof of concept...
April 13, 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28410965/permissive-role-of-reduced-inwardly-rectifying-potassium-current-density-in-the-automaticity-of-the-guinea-pig-pulmonary-vein-myocardium
#4
Yayoi Tsuneoka, Masahiko Irie, Yusuke Tanaka, Takahiko Sugimoto, Yuka Kobayashi, Taichi Kusakabe, Keisuke Kato, Shogo Hamaguchi, Iyuki Namekata, Hikaru Tanaka
The electrophysiological properties underlying the automaticity of the guinea pig pulmonary vein myocardium were studied. About 30% of the isolated pulmonary vein tissue preparations showed spontaneous electrical activity, as shown by glass microelectrode recordings from their myocardial layer. The remaining quiescent preparations had a resting membrane potential less negative than that in the left atria. Blockade of the acetylcholine activated potassium current (IK-ACh) by tertiapin induced a depolarizing shift of the resting membrane potential and automatic electrical activity in the pulmonary vein, but not in the atria...
March 28, 2017: Journal of Pharmacological Sciences
https://www.readbyqxmd.com/read/28410102/scanned-three-dimensional-intracardiac-arfi-and-swei-for-imaging-radiofrequency-ablation-lesions
#5
Peter Hollender, Lily Kuo, Virginia Chen, Stephanie Eyerly, Patrick Wolf, Gregg Trahey
Radiofrequency ablation (RFA) is used to locally disrupt electrical propagation in myocardium and treat arrhythmias, and direct visualization of ablation lesions by acoustic radiation force methods may benefit RFA procedures. This work compares four imaging modalities, B-Mode, ARFI, STL-SWEI and MTL-SWEI, in their ability to resolve RFA lesions in four ex vivo experiments. Ablation lesions are shown to be marked by at least a local halving of ARFI displacements and doubling of shear wave speeds. In a controlled ablation of ex vivo porcine and canine cardiac tissue, STL-SWEI and ARFI are shown to have similar CNR, better than MTL-SWEI and B-Mode...
April 7, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28408329/highest-dominant-frequency-and-rotor-positions-are-robust-markers-of-driver-location-during-non-invasive-mapping-of-atrial-fibrillation-a-computational-study
#6
Miguel Rodrigo, Andreu M Climent, Alejandro Liberos, Francisco Fernández-Avilés, Omer Berenfeld, Felipe Atienza, Maria S Guillem
BACKGROUND: Dominant Frequency (DF) and rotor mapping have been proposed as non-invasive techniques to guide localization of drivers maintaining atrial fibrillation (AF). OBJECTIVE: To evaluate the robustness of both techniques in identifying atrial drivers non-invasively under the effect of electrical noise or model uncertainties. METHODS: Inverse-computed DFs and phase maps were obtained on 30 different mathematical AF simulations. Epicardial Highest DF (HDF) regions and rotor location were compared with the same inverse-computed measurements after addition of noise to the ECG, size variations of the atria and linear or angular deviations in the atrial location inside the thorax...
April 10, 2017: Heart Rhythm: the Official Journal of the Heart Rhythm Society
https://www.readbyqxmd.com/read/28402037/atrial-electrophysiological-and-molecular-remodelling-induced-by-obstructive-sleep-apnoea
#7
Devika Channaveerappa, Jacob C Lux, Kelly L Wormwood, Timothy A Heintz, Meredith McLerie, Jacqueline A Treat, Hannah King, Donia Alnasser, Robert J Goodrow, Glenn Ballard, Robert Decker, Costel C Darie, Brian K Panama
Obstructive sleep apnoea (OSA) affects 9-24% of the adult population. OSA is associated with atrial disease, including atrial enlargement, fibrosis and arrhythmias. Despite the link between OSA and cardiac disease, the molecular changes in the heart which occur with OSA remain elusive. To study OSA-induced cardiac changes, we utilized a recently developed rat model which closely recapitulates the characteristics of OSA. Male Sprague Dawley rats, aged 50-70 days, received surgically implanted tracheal balloons which were inflated to cause transient airway obstructions...
April 12, 2017: Journal of Cellular and Molecular Medicine
https://www.readbyqxmd.com/read/28400367/health-literacy-and-awareness-of-atrial-fibrillation
#8
Stephanie R Reading, Alan S Go, Margaret C Fang, Daniel E Singer, In-Lu Amy Liu, Mary Helen Black, Natalia Udaltsova, Kristi Reynolds
BACKGROUND: Atrial fibrillation (AF) is the most common clinically significant arrhythmia in adults and a major risk factor for ischemic stroke. Nonetheless, previous research suggests that many individuals diagnosed with AF lack awareness about their diagnosis and inadequate health literacy may be an important contributing factor to this finding. METHODS AND RESULTS: We examined the association between health literacy and awareness of an AF diagnosis in a large, ethnically diverse cohort of Kaiser Permanente Northern and Southern California adults diagnosed with AF between January 1, 2006 and June 30, 2009...
April 11, 2017: Journal of the American Heart Association
https://www.readbyqxmd.com/read/28387822/differences-in-the-structural-characteristics-and-distribution-of-epicardial-adipose-tissue-between-left-and-right-atrial-fibrillation
#9
Hideyuki Hasebe, Kentaro Yoshida, Masataka Iida, Naoki Hatano, Toshiro Muramatsu, Akihiko Nogami, Kazutaka Aonuma
Aims: Right atrial (RA) fibrillation (RAF) was previously characterized by initiation from RA ectopies, presence of a right-to-left dominant frequency gradient during atrial fibrillation (AF), and augmentation of the gradient by adenosine triphosphate infusion. We investigated structural characteristics of the bi-atria and epicardial adipose tissue (EAT) volume in patients with RAF. Methods and results: By using multidetector computed tomography, RA, left atrial (LA), right and LA appendage (RAA and LAA, respectively) volumes, pulmonary vein (PV) sizes, and EAT volumes were compared between the RAF group (n = 8) and LA fibrillation (LAF) group (n = 32)...
April 6, 2017: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/28386845/sub-physiological-oxygen-levels-optimal-for-growth-and-survival-of-human-atrial-cardiac-stem-cells
#10
Deepthi Sreerengam RajendranNair, Jayakumar Karunakaran, Renuka R Nair
Cardiac stem cells reside in niches where the oxygen levels are close to 3%. For cytotherapy, cells are conventionally expanded in ambient oxygen (21% O2) which represents hyperoxia compared to the oxygen tension of niches. Cardiosphere-derived cells (CDCs) are then transplanted to host tissue with lower-O2 levels. The high-O2 gradient can reduce the efficacy of cultured cells. Based on the assumption that minimizing injury due to O2 gradients will enhance the yield of functionally efficient cells, CDCs were cultured in 3% O2 and compared with cells maintained in ambient O2...
April 6, 2017: Molecular and Cellular Biochemistry
https://www.readbyqxmd.com/read/28382232/resveratrol-enhances-the-inotropic-effect-but-inhibits-the-proarrhythmic-effect-of-sympathomimetic-agents-in-rat-myocardium
#11
Jesús Hernandez-Cascales
BACKGROUND: Resveratrol is a cardioprotective agent with known antiarrhythmic effects that has recently been shown to inhibit phosphodiesterase (PDE) enzyme activity. Thus, it is possible that resveratrol increases the inotropic effect of sympathomimetic agents, as PDE inhibitors do but, unlike other PDE inhibitors, its effect may not be accompanied by proarrhythmia due to its antiarrhythmic action. This work is aimed to test this hypothesis. METHODS: This is an "in vitro" concentration-response relationship study...
2017: PeerJ
https://www.readbyqxmd.com/read/28370213/left-ventricular-basal-inferior-pseudoaneurysm-and-left-atrial-dissection-after-myocardial-infarction-case-report
#12
Rui Azevedo Guerreiro, Kisa Congo, João Carvalho, João Pais, Diogo Brás, Bruno Piçarra, Agostinho Caeiro, José Aguiar
Left atrial dissection is a rare entity, mostly occurring after mitral valve surgery, with only a few cases described after myocardial infarction. The authors report a case of a 60-year-old man who presented with an inferior myocardial infarction, complicated with pseudoaneurysm of basal segment of left ventricular inferior wall, which expanded through the mitral ring to left atria, causing left atrial free wall dissection. The left ventriculo-atrial communication through the pseudoaneurysm caused major para-mitral regurgitation and the development of acute heart failure...
March 31, 2017: Echocardiography
https://www.readbyqxmd.com/read/28363682/twelve-month-outcome-of-patients-with-an-established-indication-for-oral-anticoagulation-undergoing-coronary-artery-stenting-and-stratified-by-the-baseline-risk-of-bleeding-insights-from-the-warfarin-and-coronary-stenting-war-stent-registry
#13
Andrea Rubboli, Francesco Saia, Alessandro Sciahbasi, Antonio M Leone, Cataldo Palmieri, Maria Letizia Bacchi-Reggiani, Paolo Calabrò, Barbara Bordoni, Giacomo Piccalò, Nicoletta Franco, Annamaria Nicolino, Paolo Magnavacchi, Luigi Vignali, Stefano Mameli, Michele Dallago, Stefano Maggiolini, Luigi Steffanon, Giancarlo Piovaccari, Giuseppe Di Pasquale
PURPOSE: To evaluate the outcome of patients with an established indication for oral anticoagulation (OAC) undergoing coronary stent implantation (PCI-S) and stratified by the baseline risk of bleeding. MATERIAL AND METHODS: The database of the prospective, multicentre, observational WAR-STENT registry (ClinicalTrials.gov identifier NCT00722319) was analyzed and patients with atrial fibrillation and CHA2DS2-VASc score ≥2, mechanical heart valve, prior cardiac embolism, intra-cardiac thrombus and recent venous thromboembolism who were treated with either triple (warfarin, aspirin and clopidogrel) or dual (warfarin and clopidogrel) or dual antiplatelet (aspirin and clopidogrel) therapy, identified...
March 19, 2017: Cardiovascular Revascularization Medicine: Including Molecular Interventions
https://www.readbyqxmd.com/read/28359135/scoring-systems-for-estimating-the-risk-of-anticoagulant-associated-bleeding
#14
Anna L Parks, Margaret C Fang
Anticoagulant medications are frequently used to prevent and treat thromboembolic disease. However, the benefits of anticoagulants must be balanced with a careful assessment of the risk of bleeding complications that can ensue from their use. Several bleeding risk scores are available, including the Outpatient Bleeding Risk Index, HAS-BLED, ATRIA, and HEMORR2HAGES risk assessment tools, and can be used to help estimate patients' risk for bleeding on anticoagulants. These tools vary by their individual risk components and in how they define and weigh clinical factors...
March 30, 2017: Seminars in Thrombosis and Hemostasis
https://www.readbyqxmd.com/read/28345131/effect-of-botulinum-toxin-on-inducibility-and-maintenance-of-atrial-fibrillation-in-ovine-myocardial-tissue
#15
Alireza Nazeri, Anand V Ganapathy, Ali Massumi, Mehran Massumi, Egemen Tuzun, Raymond Stainback, Ana-Maria Segura, Macarthur A Elayda, Mehdi Razavi
BACKGROUND: Aberrant vagal stimulation may promote the generation and propagation of atrial fibrillation (AF). Researchers have suggested that botulinum toxin (BTX), a neurotoxin that decreases neural vagal stimulation, may decrease the incidence of postoperative AF. The exact electrophysiologic mechanism underlying the observations and histopathologic alterations associated with BTX are unclear. OBJECTIVE: To investigate the electrophysiologic, functional, and histopathologic effects of BTX on fibrillation induction in ovine atria...
March 27, 2017: Pacing and Clinical Electrophysiology: PACE
https://www.readbyqxmd.com/read/28343787/relationship-between-rotors-and-complex-fractionated-electrograms-in-atrial-fibrillation-using-a-novel-computational-analysis
#16
Pedro Adragão, Pedro Carmo, Diogo Cavaco, João Carmo, António Ferreira, Francisco Moscoso Costa, Maria Salomé Carvalho, João Mesquita, Rita Quaresma, Francisco Belo Morgado, Miguel Mendes
INTRODUCTION: Rotors and complex fractionated atrial electrograms (CFAEs) have been suggested as possible therapeutic targets in ablation of atrial fibrillation (AF). The aim of this study was to assess the relationship between rotors and CFAEs in patients with AF. METHODS: We studied 18 patients with AF (mean age 69±8 years, 33% female) who underwent rotor ablation and pulmonary vein isolation. Endocardial mapping was performed with a basket catheter to identify the presence, number and location of rotors and CFAEs...
April 2017: Portuguese Journal of Cardiology: An Official Journal of the Portuguese Society of Cardiology
https://www.readbyqxmd.com/read/28328743/acetylcholine-atropine-interactions-paradoxical-effects-on-atrial-fibrillation-inducibility
#17
Yu Liu, Benjamin J Scherlag, Youqi Fan, Wenfang Xia, He Huang, Sunny S Po
Atropine (ATr) is well known as a cholinergic antagonist, however, at low concentrations ATr could paradoxically accentuate the parasympathetic actions of acetylcholine (ACh). In 22 pentobarbital anesthetized dogs, via a left and right thoracotomy, a leak proof barrier was attached to isolate the atrial appendages (AAs) from the rest of the atria. In Group 1(Ach+ATr+Ach), ACh, 100 mM, was placed on the AA followed by the application of ATr, 2mg/cc. The average AFdur was 17±7 minutes. After ATr was applied to the AA and ACh again tested, the AFdur was markedly attenuated (2±2 minutes, p<0...
March 21, 2017: Journal of Cardiovascular Pharmacology
https://www.readbyqxmd.com/read/28322838/effect-of-antiarrhythmic-drugs-on-small-conductance-calcium-activated-potassium-channels
#18
Rafel Simó-Vicens, Daniel R P Sauter, Morten Grunnet, Jonas G Diness, Bo H Bentzen
Atrial fibrillation (AF) is the most common type of arrhythmia. Current pharmacological treatment for AF is moderately effective and/or increases the risk of serious ventricular adverse effects. To avoid ventricular adverse effects, a new target has been considered, the small conductance calcium-activated K(+) channels (KCa2.X, SK channels). In the heart, KCa2.X channels are functionally more important in atria compared to ventricles, and pharmacological inhibition of the channel confers atrial selective prolongation of the cardiac action potential and converts AF to sinus rhythm in animal models of AF...
May 15, 2017: European Journal of Pharmacology
https://www.readbyqxmd.com/read/28320863/rac1-gtpase-regulates-11%C3%AE-hydroxysteroid-dehydrogenase-type-2-and-fibrotic-remodeling
#19
Daniel Lavall, Pia Schuster, Nadine Jacobs, Andrey Kazakov, Michael Böhm, Ulrich Laufs
The aim of the study was to characterize the role of Rac1 GTPase for the mineralocorticoid receptor (MR) mediated pro-fibrotic remodeling. Transgenic mice with cardiac overexpression of constitutively active Rac1 (RacET) develop an age-dependent phenotype with atrial dilatation, fibrosis and atrial fibrillation. Expression of MR was similar in RacET and wild-type (WT) mice. The expression of 11β hydroxysteroid dehydrogenase type 2 (11β-HSD2) was age-dependently upregulated in the atria and the left ventricles of RacET mice on mRNA and protein level...
March 20, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28318421/the-kaleidoscopic-nature-of-griefgrief-is-a-journey-finding-your-path-through-loss-by-kenneth-j-doka-new-york-ny-atria-books-2016-304-pp-isbn-978-1476771480-26-00-hardcover
#20
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