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https://www.readbyqxmd.com/read/29452989/prognostic-role-of-cardiac-calcifications-in-primary-prevention-a-powerful-marker-of-adverse-outcome-highly-dependent-on-underlying-cardiac-rhythm
#1
Carmine Mazzone, Gianni Cioffi, Concetta Di Nora, Giulia Barbati, Federica Guidetti, Pompilio Faggiano, Nicola Gaibazzi, Giorgio Faganello, Endria Casanova Borca, Andrea Di Lenarda
BACKGROUND: Increasing evidence exists regarding calcium detected in aortic cusps and/or mitral annulus (AOC_MAC) at transthoracic echocardiogram as a predictor of cardiovascular (CV) events and mortality. PURPOSE: To verify whether AOC_MAC has a prognostic role in the setting of primary prevention independently of the presence of atrial fibrillation (AF). METHODS: All subjects consecutively referred from January 2011 to October 2014 to the Cardiovascular Centre for CV risk assessment in primary prevention were selected...
January 31, 2018: International Journal of Cardiology
https://www.readbyqxmd.com/read/29438999/characteristics-of-single-loop-macroreentrant-biatrial-tachycardia-diagnosed-by-ultrahigh-resolution-mapping-system
#2
Takeshi Kitamura, Ruairidh Martin, Arnaud Denis, Masateru Takigawa, Alexandre Duparc, Anne Rollin, Antonio Frontera, Nathaniel Thompson, Gregoire Massoullié, Ghassen Cheniti, Michael Wolf, Konstantinos Vlachos, Claire A Martin, Nora Al Jefairi, Josselin Duchateau, Nicolas Klotz, Thomas Pambrun, Frédéric Sacher, Hubert Cochet, Meleze Hocini, Michel Haïssaguerre, Philippe Maury, Pierre Jaïs, Nicolas Derval
BACKGROUND: Biatrial tachycardia (BiAT) is a rare form of atrial macroreentrant tachycardia, in which both atria form a critical part of the circuit. We aimed to identify the characteristics and precise circuits of single-loop macroreentrant BiATs. METHODS AND RESULTS: We identified 8 patients (median age, 59.5 years old) with 9 BiATs in a cohort of 336 consecutive patients from 2 institutions who had undergone AT catheter ablation using an automatic ultrahigh-resolution mapping system...
February 2018: Circulation. Arrhythmia and Electrophysiology
https://www.readbyqxmd.com/read/29436789/evaluation-of-chronic-losartan-treatment-effect-on-cardiac-chronotropic-dysfunction-in-biliary-cirrhotic-rats
#3
Farahnaz Jazaeri, Razieh Afsharmoghaddam, Alireza Abdollahi, Giti Ghamami, Ahmad Reza Dehpour
Cirrhosis is associated with cardiac chronotropic and inotropic dysfunction which is known as cirrhotic cardiomyopathy. Cardiac responsiveness to adrenergic stimulation is impaired in cirrhosis. Moreover, there is vagal nerve dysfunction which is related to neuromodulatory dysfunction of the angiotensin II in the cirrhosis. This study was aimed to explore the hypothesis that administration of Losartan-angiotensin II receptor antagonist increases cardiac chronotropic response to isoproterenol in cirrhotic rats; and if so, whether this is associated with altered cardiac TGF-β receptor expression...
January 2018: Acta Medica Iranica
https://www.readbyqxmd.com/read/29429060/electrophysiological-differences-in-cholinergic-signaling-between-the-hearts-of-summer-and-winter-frogs-rana-temporaria
#4
Denis Abramochkin, Vladislav Kuzmin
The striking seasonal difference in sensitivity of frog cardiac muscle to acetylcholine or stimulation of parasympathetic nervous fibers has been noted almost a century ago, although its electrophysiological basis has never been revealed. The present study compares the effects of the muscarinic agonist carbamylcholine chloride (CCh 10-8-10-5 M) on electrical activity in isolated atrial and ventricular preparations from dormant frogs (Rana temporaria) caught in January (winter-acclimatized, WA) and from active frogs caught in July (summer-acclimatized, SA)...
February 10, 2018: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/29407081/major-bleeding-and-intracranial-hemorrhage-risk-prediction-in-patients-with-atrial-fibrillation-attention-to-modifiable-bleeding-risk-factors-or-use-of-a-bleeding-risk-stratification-score-a-nationwide-cohort-study
#5
Tze-Fan Chao, Gregory Y H Lip, Yenn-Jiang Lin, Shih-Lin Chang, Li-Wei Lo, Yu-Feng Hu, Ta-Chuan Tuan, Jo-Nan Liao, Fa-Po Chung, Tzeng-Ji Chen, Shih-Ann Chen
BACKGROUND: While modifiable bleeding risks should be addressed in all patients with atrial fibrillation (AF), use of a bleeding risk score enables clinicians to 'flag up' those at risk of bleeding for more regular patient contact reviews. We compared a risk assessment strategy for major bleeding and intracranial hemorrhage (ICH) based on modifiable bleeding risk factors (referred to as a 'MBR factors' score) against established bleeding risk stratification scores (HEMORR 2 HAGES, HAS-BLED, ATRIA, ORBIT)...
March 1, 2018: International Journal of Cardiology
https://www.readbyqxmd.com/read/29402528/influence-of-chronic-volume-overload-induced-atrial-remodeling-on-electrophysiological-responses-to-cholinergic-receptor-stimulation-in-the-isolated-rat-atria
#6
Xin Cao, Megumi Aimoto, Marie Fukumoto, Yoshinobu Nagasawa, Hikaru Tanaka, Akira Takahara
Whereas molecular mechanisms of atrial fibrillation (AF) have been widely investigated, there is limited information regarding interrelation between chronic volume overload and parasympathetic nervous system in the pathophysiology of AF. In this study, we investigated the influence of abdominal aorto-venocaval shunt (AVS)-induced atrial remodeling on electrophysiological responses to cholinergic receptor stimulation in the isolated rat atria. Interstitial fibrosis, cardiomyocyte hypertrophy and atrial enlargement, known as structural arrhythmogenic substrates for AF, took place after one month of AVS operation...
January 16, 2018: Journal of Pharmacological Sciences
https://www.readbyqxmd.com/read/29390872/the-potassium-channel-blocker-dalfampridine-diminishes-ouabain-induced-arrhythmia-in-isolated-rat-atria
#7
Nahid Ghebleh Zadeh, Gholamhassan Vaezi, Azam Bakhtiarian, Zahra Mousavi, Abdolhossein Shiravi, Vahid Nikoui
The aim of the present experiment was to investigate the possible antiarrhythmic effects of dalfampridine in ouabain-induced arrhythmia in rats. Twenty-four male rats including the control and dalfampridine-incubated (100 µM to 10 mM) ouabain-stimulated (40 µM) groups were used. After induction of anesthesia, the atria were isolated and the time of onset of arrhythmia and asystole were recorded. The contractile force of atria was also measured. Dalfampridine at concentration of 1 mM significantly postponed the onset of arrhythmia and asystole compared to control group (p ≤ ...
February 1, 2018: Archives of Physiology and Biochemistry
https://www.readbyqxmd.com/read/29378361/assessment-of-thrombotic-risk-in-atrial-fibrillation-with-ultrasound-molecular-imaging-of-p-selectin
#8
Yuanwen Jing, Yinlan Hu, Hairui Li, Junfen Wang, Xiaoyun Si, Hao Zheng, Jian Liu, Wangjun Liao, Yulin Liao, Jianping Bin
Molecular imaging of inflammatory mediators in atria may contribute to thrombotic risk assessment of atrial fibrillation (AF). We investigated the feasibility of ultrasound molecular imaging (UMI) targeted to P-selectin to assess thrombotic risk in AF. Rat AF models were established with rapid atrial pacing. Microbubbles targeted to P-selectin were injected into the rats, followed by left atrial (LA) UMI examination. Furthermore, P-selectin, platelets (PLTs), fibrin and tissue factor (TF) of LA were detected by histopathology and scanning electron microscopy...
February 2018: Thrombosis and Haemostasis
https://www.readbyqxmd.com/read/29377578/luminescent-nanoparticles-for-rapid-monitoring-of-endogenous-acetylcholine-release-in-mice-atria
#9
Alsu Mukhametshina, Alexey Petrov, Svetlana Fedorenko, Konstantin Petrov, Irek Nizameev, Asiya Mustafina, Oleg Sinyashin
The present work introduces for the first time a nanoparticulate approach for ex vivo monitoring of acetylcholinesterase-catalyzed hydrolysis of endogenous acetylcholine released from nerve varicosities in mice atria. Amino-modified 20-nm size silica nanoparticles (SNs) doped by luminescent Tb(III) complexes were applied as the nanosensors. Their sensing capacity results from the decreased intensity of Tb(III)-centred luminescence due to the quenching effect of acetic acid derived from acetylcholinesterase-catalyzed hydrolysis of acetylcholine...
January 29, 2018: Luminescence: the Journal of Biological and Chemical Luminescence
https://www.readbyqxmd.com/read/29375091/assessment-of-cuspal-deflection-and-volumetric-shrinkage-of-different-bulk-fill-composites-using-non-contact-phase-microscopy-and-micro-computed-tomography
#10
Martin Prager, Mark Pierce, Pablo J Atria, Camila Sampaio, Eduardo Cáceres, Mark Wolff, Marcelo Giannini, Ronaldo Hirata
The understanding of cuspal deflection and volumetric shrinkage of resin composites is necessary to assess and improve the placement techniques of resin-based materials. The aim of this study was to investigate the cuspal deflection and its relationship with volumetric polymerization shrinkage of different bulk-fill resin composites. The investigation was conducted using non-contact phase microscopy and micro-computed tomography. Thirty custom-milled aluminum blocks were fabricated for microscopy analysis and thirty-six tooth models with standardized Class I cavities were used for micro-computed tomography analysis...
January 26, 2018: Dental Materials Journal
https://www.readbyqxmd.com/read/29364554/validation-of-a-novel-mapping-system-and-utility-for-mapping-complex-atrial-tachycardias
#11
S Honarbakhsh, R J Hunter, G Dhillon, W Ullah, E Keating, R Providencia, A Chow, M J Earley, R J Schilling
INTRODUCTION: This study sought to validate a novel wavefront mapping system utilizing whole-chamber basket catheters (CARTOFINDER, Biosense Webster). The system was validated in terms of (1) mapping atrial-paced beats and (2) mapping complex wavefront patterns in atrial tachycardia (AT). METHODS AND RESULTS: Patients undergoing catheter ablation for AT and persistent AF were included. A 64-pole-basket catheter was used to acquire unipolar signals that were processed by CARTOFINDER mapping system to generate dynamic wavefront propagation maps...
January 24, 2018: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/29360953/transcriptional-regulation-of-stress-kinase-jnk2-in-pro-arrhythmic-camkii%C3%AE-expression-in-the-aged-atrium
#12
Xianlong Gao, Xiaomin Wu, Jiajie Yan, Jingqun Zhang, Weiwei Zhao, Dominic DeMarco, Yongguo Zhang, Mamdouh Bakhos, Gregory Mignery, Jun Sun, Zhenyu Li, Michael Fill, Xun Ai
Introduction: c-jun N-terminal kinase (JNK) is a critical stress response kinase that activates in a wide range of physiological and pathological cellular processes. We recently discovered a pivotal role of JNK in the development of atrial arrhythmias in the aged heart, while cardiac CaMKIIδ, another pro-arrhythmic molecule, was also found to enhance atrial arrhythmogenicity. Here, we aimed to reveal a regulatory role of the stress kinase JNK2 isoform on CaMKIIδ expression. Methods and Results: Activated JNK2 leads to increased CaMKIIδ protein expression in aged human and mouse atria, evidenced from the reversal of CaMKIIδ up-regulation in JNK2 inhibitor treated wild-type aged mice...
January 19, 2018: Cardiovascular Research
https://www.readbyqxmd.com/read/29360837/modeling-specific-action-potentials-in-the-human-atria-based-on-a-minimal-single-cell-model
#13
Yvonne Richter, Pedro G Lind, Philipp Maass
We present an effective method to model empirical action potentials of specific patients in the human atria based on the minimal model of Bueno-Orovio, Cherry and Fenton adapted to atrial electrophysiology. In this model, three ionic are currents introduced, where each of it is governed by a characteristic time scale. By applying a nonlinear optimization procedure, a best combination of the respective time scales is determined, which allows one to reproduce specific action potentials with a given amplitude, width and shape...
2018: PloS One
https://www.readbyqxmd.com/read/29352041/stress-signaling-jnk2-crosstalk-with-camkii-underlies-enhanced-atrial-arrhythmogenesis
#14
Jiajie Yan, Weiwei Zhao, Justin K Thomson, Xianlong Gao, Dominic M DeMarco, Elena Carrillo, Biyi Chen, Xiaomin Wu, Kenneth S Ginsburg, Mamdouh Bakhos, Donald M Bers, Mark E Anderson, Long-Sheng Song, Michael Fill, Xun Ai
Rationale: Atrial fibrillation (AF) is the most common arrhythmia and advanced age is an inevitable and predominant AF risk factor. However, the mechanisms that couple aging and AF propensity remain unclear, making targeted therapeutic interventions unattainable. Objective: To explore the functional role of an important stress-response c-Jun N-terminal kinase (JNK) in sarcoplasmic reticulum (SR) Ca2+ handling and consequently Ca2+-mediated atrial arrhythmias. Methods and Results: We employed a series of cutting-edge electrophysiological and molecular techniques, exploited the power of transgenic mouse models to detail the molecular mechanism, and verified its clinical applicability in parallel studies on donor human hearts...
January 19, 2018: Circulation Research
https://www.readbyqxmd.com/read/29350387/clinical-anatomy-of-human-heart-atria-and-interatrial-septum-anatomical-basis-for-interventional-cardiologists-and-electrocardiologists-part-1-right-atrium-and-interatrial-septum
#15
Iwona Kucybała, Katarzyna Ciuk, Wiesława Klimek-Piotrowska
No abstract text is available yet for this article.
January 19, 2018: Kardiologia Polska
https://www.readbyqxmd.com/read/29342363/differential-effects-of-inhibitory-g-protein-isoforms-on-g-protein-gated-inwardly-rectifying-k-currents-in-adult-murine-atria
#16
Muriel Nobles, David Montaigne, Sonia Sebastian, Lutz Birnbaumer, Andrew Tinker
G-protein gated inwardly rectifying K+ (GIRK) channels are the major inwardly rectifying K+ currents in cardiac atrial myocytes and an important determinant of atrial electrophysiology. Inhibitory G-protein alpha subunits can both mediate activation via acetylcholine but can also supress basal currents in the absence of agonist. We studied this phenomenon using whole cell patch clamping in murine atria from mice with global genetic deletion of Gαi2, combined deletion of Gαi1/Gαi3 and littermate controls...
January 17, 2018: American Journal of Physiology. Cell Physiology
https://www.readbyqxmd.com/read/29332414/-interatrial-block-and-its-clinical-relevance-renaissance-of-an-ecg-change
#17
János Tomcsányi
Interatrial block involves conduction delay between the right and left atria during sinus rhythm. The review describes the classification, pathomechanism and clinical significance of this under-recognised ECG sign, nominated Bayés syndrome. The presented ECGs help to recognise the differentypes of interatrial blocks. Orv Hetil. 2018; 159(3): 91-95.
January 2018: Orvosi Hetilap
https://www.readbyqxmd.com/read/29326832/at-the-atrioventricular-crossroads-dual-pathway-electrophysiology-in-the-atrioventricular-node-and-its-underlying-heterogeneities
#18
Sharon A George, N Rokhaya Faye, Alejandro Murillo-Berlioz, K Benjamin Lee, Gregory D Trachiotis, Igor R Efimov
The atrioventricular node (AVN) is a complex structure that performs a variety of functions in the heart. The AVN is primarily an electrical gatekeeper between the atria and ventricles and introduces a delay between atrial and ventricular excitation, allowing for efficient ventricular filling. The AVN is composed of several compartments that safely transmit electrical excitation from the atria to the ventricles via the fast or slow pathways. There are many electrophysiological differences between these pathways, including conduction time and electrical refractoriness, that increase the predisposition of the atrioventricular junction to arrhythmias such as atrioventricular nodal re-entrant tachycardia...
December 2017: Arrhythmia & Electrophysiology Review
https://www.readbyqxmd.com/read/29324261/platelet-toll-like-receptor-and-its-ligand-hmgb-1-expression-is-increased-in-the-left-atrium-of-atrial-fibrillation-patients
#19
Kadri Murat Gurses, Duygu Kocyigit, Muhammed Ulvi Yalcin, Hande Canpinar, Banu Evranos, Ugur Canpolat, Hikmet Yorgun, Levent Sahiner, Dicle Guc, Kudret Aytemir
BACKGROUND: Atrial fibrillation(AF) is the most common sustained arrhythmia. Its most feared sequelae are stroke and peripheral thromboembolism due to atrial thrombi formation. Mechanisms underlying the relationship between platelet activation and left atrial thrombi have not been clearly elucidated yet. We aimed to investigate whether immune-mediated platelet activation occurred in AF patients in this cross-sectional study. METHODS: Persistent and paroxysmal AF patients who underwent cryoballoon-based AF ablation between March 2015 and July 2016 were included as the patient group...
January 8, 2018: Cytokine
https://www.readbyqxmd.com/read/29318371/proteomics-and-transcriptomics-in-atrial-fibrillation
#20
REVIEW
Marc Sühling, Carmen Wolke, Christian Scharf, Uwe Lendeckel
Atrial fibrillation (AF) is the most common tachyarrhythmia. AF, due to substantial remodeling processes initiated in the atria, is a typically self-sustaining and progressive disease. Atrial remodeling has been intensively investigated at the molecular level in recent decades. Although the application of "omics" technologies has already significantly contributed to our current understanding of the pathophysiology of AF, the complexity of the latter and the large heterogeneity of AF patients remained a major limitation...
January 9, 2018: Herzschrittmachertherapie & Elektrophysiologie
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