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isolated atria

Zhaoye Zhou, Qi Jin, Long Yu, Liqun Wu, Bin He
BACKGROUND: Knowledge of atrial electrophysiological properties is crucial for clinical intervention of atrial arrhythmias and the investigation of the underlying mechanism. This study aims to evaluate the feasibility of a novel noninvasive cardiac electrical imaging technique in imaging bi-atrial activation sequences from body surface potential maps (BSPMs). METHODS: The study includes 7 subjects, with 3 atrial flutter patients, and 4 healthy subjects with normal atrial activations...
2016: PloS One
Lamei Yu, Kuichang Yuan, Hoang Thi Ai Phuong, Byung Mun Park, Suhn Hee Kim
Angiotensin-(1-5) [Ang-(1-5)], which is a metabolite of Angiotensin-(1-7) [Ang-(1-7)] catalyzed by angiotensin-converting enzyme (ACE), is a pentapeptide of the renin-angiotensin system (RAS). It has been reported that Ang-(1-7) and Ang-(1-9) stimulate the secretion of atrial natriuretic peptide (ANP) via Mas receptor (Mas R) and Ang II type 2 receptor (AT2R), respectively. However, it still remains unknown whether Ang-(1-5) has a similar function to Ang-(1-7). We investigated the effect of Ang-(1-5) on ANP secretion and to define its signaling pathway using isolated perfused beating rat atria...
September 20, 2016: Peptides
Antoine H G Driessen, Wouter R Berger, Sébastien P J Krul, Nicoline W E van den Berg, Jolien Neefs, Femke R Piersma, Dean R P P Chan Pin Yin, Jonas S S G de Jong, WimJan P van Boven, Joris R de Groot
BACKGROUND: Patients with long duration of atrial fibrillation (AF), enlarged atria, or failed catheter ablation have advanced AF and may require more extensive treatment than pulmonary vein isolation. OBJECTIVES: The aim of this study was to investigate the efficacy and safety of additional ganglion plexus (GP) ablation in patients undergoing thoracoscopic AF surgery. METHODS: Patients with paroxysmal AF underwent pulmonary vein isolation...
September 13, 2016: Journal of the American College of Cardiology
Asya Makhro, Qinghai Tian, Lars Kaestner, Dmitry Kosenkov, Giuseppe Faggian, Max Gassmann, Colin Schwarzwald, Anna Bogdanova
This study focuses on characterization of the cardiac N-methyl D-aspartate receptors (NMDARs) as a target for endogenous and synthetic agonists and antagonists. Using isolated perfused rat hearts, we have shown that intracoronary administration of the NMDAR agonists and antagonists has a pronounced effect on autonomous heart function. Perfusion of rat hearts with autologous blood supplemented with NMDAR agonists was associated with induction of tachycardia, sinus arrhythmia and ischemia occurring within physiological plasma concentration range for glutamate and glycine...
August 10, 2016: Journal of Cardiovascular Pharmacology
Jens Buttgereit, Julia Shanks, Dan Li, Guoliang Hao, Arvinder Athwal, Thomas H Langenickel, Hannah Wright, Andrey C da Costa Goncalves, Jan Monti, Ralph Plehm, Elena Popova, Fatimunnisa Qadri, Irina Lapidus, Brent Ryan, Cemil Özcelik, David J Paterson, Michael Bader, Neil Herring
AIMS: B-type natriuretic peptide (BNP)-natriuretic peptide receptor A (NPR-A) receptor signalling inhibits cardiac sympathetic neurotransmission, although C-type natriuretic peptide (CNP) is the predominant neuropeptide of the nervous system with expression in the heart and vasculature. We hypothesized that CNP acts similarly to BNP, and that transgenic rats (TGRs) with neuron-specific overexpression of a dominant negative NPR-B receptor would develop heightened sympathetic drive. METHODS AND RESULTS: Mean arterial pressure and heart rate (HR) were significantly (P < 0...
August 5, 2016: Cardiovascular Research
Zhi-Yu Wei, Bai-Ri Cui, Xun Cui, Yan-Ling Wu, Yang Fu, Li-Ping Liu, Hu-Ri Piao
In the present study, four novel series of 4-phenyl-1H-1,2,4-triazol-5(4H)-one derivatives containing triazole or piperazine moieties were designed, synthesized and evaluated for negative inotropic activity by measuring the left atrium stroke volume in isolated rabbit heart preparations. Almost all of the compounds showed an ability to moderate the cardiac workload by decreasing the heart rate and contractility. Among them, 7h was found to be the most potent with a change in stroke volume of -48.22 ± 0.36% at a concentration of 3×10(-5) mol/L (metoprolol: -9...
July 28, 2016: Chemical Biology & Drug Design
Katarína Bruchatá, Andrej Némethy, Ružena Čižmáriková, Eva Račanská, Ladislav Habala
The structure-activity relationships of 13 analogs of aryloxyaminopropanol type derived from 2-hydroxyphenylethanone as potential β-blockers are described. The synthesized compounds possess an isopropyl or a tert-butyl group in the hydrophilic part of the molecule and an alkoxymethyl substitution in the lipophilic moiety. The target compounds were prepared by an established four-step method and their structures were confirmed by interpretation of their UV, IR, (1) H NMR and (13) C NMR spectra, and by elemental analysis...
September 2016: Archiv der Pharmazie
Chiara Foglieni, Raffaella Rusconi, Maria Elena Mantione, Gabriele Fragasso, Ottavio Alfieri, Francesco Maisano
OBJECTIVE: Left atrial (LA) enlargement, a compensatory mechanism in chronic mitral regurgitation (MR) increasing the risk of atrial fibrillation (AF) and predictive of cardiac events, involves structural alterations. We characterized LA features in patients in sinus rhythm with severe degree of MR, similar degrees of left ventricular remodeling but divergent LA size. METHODS: Among a consecutive series of 163 patients in stable sinus rhythm undergoing isolated mitral valve surgery for severe non-rheumatic MR, two groups were arbitrarily selected according to their LA size (antero-posterior): NRLA group (non-remodeled LA) included 8 patients with LA≤40mm, RLA group (remodeled LA) included 8 patients with LA>55mm...
September 15, 2016: International Journal of Cardiology
Dionyssios Leftheriotis, Panayota Flevari, Charalampos Kossyvakis, Dimitrios Katsaras, Chrysanthi Batistaki, Chrysa Arvaniti, Georgios Giannopoulos, Spyridon Deftereos, Georgia Kostopanagiotou, Ioannis Lekakis
BACKGROUND: In experimental models, stellate ganglion block (SGB) reduces the induction of atrial fibrillation (AF), while data in humans are limited. OBJECTIVE: The aim of this study was to assess the effect of unilateral SGB on atrial electrophysiological properties and AF induction in patients with paroxysmal AF. METHODS: Thirty-six patients with paroxysmal AF were randomized in a 2:1 order to temporary, transcutaneous, pharmaceutical SGB with lidocaine or placebo before pulmonary vein isolation...
June 21, 2016: Heart Rhythm: the Official Journal of the Heart Rhythm Society
Borut Geršak, Matevž Jan
BACKGROUND: The objective of this single-center study was to report long-term efficacy outcomes of the convergent procedure for the treatment of atrial fibrillation. METHODS: Outcomes for the convergent procedure were determined by clinical presentation and interrogating implanted loop recorders. Rhythm status and required interventions for atrial fibrillation recurrence (antiarrhythmic drugs, cardioversions, and repeat ablations) were quantified 1 to 4 years after the procedure...
June 24, 2016: Annals of Thoracic Surgery
Mahir Gachabayov, Dmitriy Neronov
No abstract text is available yet for this article.
April 2016: International Journal of Critical Illness and Injury Science
J Trent Magruder, Sarah Collica, Stephen Belmustakov, Todd C Crawford, Joshua C Grimm, Duke E Cameron, William A Baumgartner, Kaushik Mandal
BACKGROUND: We sought to determine the incidence of and risk factors for late-onset atrial fibrillation (LOAF) in patients with preserved ejection fractions undergoing mitral valve repair METHODS: We included patients undergoing isolated mitral valve repair (MVR) for degenerative disease between 1997-2014 at our institution with EF ≥60%. Patients who had AF preoperatively were excluded from the final analysis. Our primary outcome, LOAF, was defined as AF occurring after discharge following MVR (≥9 days)...
August 2016: Journal of Cardiac Surgery
Jayaprakash Shenthar, Saligrama Ramegowda Kalpana, Mukund A Prabhu, Maneesh K Rai, Ravikumar Kalyani Nagashetty, Giridhar Kamlapurkar
BACKGROUND: Mitral stenosis (MS) has the highest incidence of atrial fibrillation (AF) in chronic rheumatic valvular disease. There are very few studies in isolated MS comparing histopathological changes in patients with sinus rhythm (SR) and AF. OBJECTIVES: To analyze the histological changes associated with isolated MS and compare between changes in AF and SR. METHODS: This was a prospective study in patients undergoing valve replacement surgery for symptomatic isolated MS who were divided into 2 groups, Group I AF (n = 13) and Group II SR (n = 10)...
September 2016: Journal of Cardiovascular Electrophysiology
R B Tang, Z L Wang, Y H Yin, Z H Zhang, Z Q Li, J Cao, K J Cao, Y Z Yang, H Jiang, P Z Yang, B He, X Liu, Y X Sun, C S Ma
OBJECTIVE: To verify the safety and efficacy of the domestic 3D cardiac electrophysiological mapping system for catheter ablation of persistent atrial fibrillation (AF). METHODS: From December 2011 to April 2014, 255 patients (184 male) with persistent AF in 13 centers were enrolled in this multicenter prospective controlled study.The patients were allocated to catheter ablation group (experiment group) and antiarrhythmics drugs cardioversion group (control group) with the ratio 2∶1 according to the patients' intention...
May 24, 2016: Zhonghua Xin Xue Guan Bing za Zhi
Kuichang Yuan, Byung Mun Park, Young Tae Choi, Jong Hun Kim, Kyung Woo Cho, Suhn Hee Kim
The endothelins (ET) peptide family consists of ET-1, ET-2, ET-3, and sarafotoxin (s6C, a snake venom) and their actions appears to be different among isoforms. The aim of this study was to compare the secretagogue effect of ET-1 on atrial natriuretic peptide (ANP) secretion with ET-3 and evaluate its physiological meaning. Isolated nonbeating atria from male Sprague-Dawley rats were used to evaluate stretch-activated ANP secretion in response to ET-1, ET-2, ET-3, and s6C. Changes in mean blood pressure (MAP) were measured during acute injection of ET-1 and ET-3 with and without natriuretic peptide receptor-A antagonist (A71915) in anesthetized rats...
August 2016: Peptides
Matteo Micucci, Andrea Angeletti, Massimiliano Cont, Ivan Corazza, Rita Aldini, Elisa Donadio, Alberto Chiarini, Roberta Budriesi
Olea europaea L. leaves extract (Oe) and Hybiscus sabdariffa L. flowers extract (Hs) have calcium antagonistic properties. Aim of this work was to study the cardiovascular effects of Pres Phytum(®), a nutraceutical formulation containing a mixture of the two extracts and the excipients, and investigate its possible off-target effects, using in vitro biological assays on guinea pig isolated organs. Cardiovascular effects were assessed using guinea pig atria and aorta. The effects of Pres Phytum on spontaneous gastrointestinal, urinary, and respiratory tracts smooth muscle contractility were evaluated...
May 2016: Journal of Medicinal Food
Jason D Bayer, Caroline H Roney, Ali Pashaei, Pierre Jaïs, Edward J Vigmond
Pulmonary vein isolation (PVI) with radiofrequency ablation (RFA) is the cornerstone of atrial fibrillation (AF) therapy, but few strategies exist for when it fails. To guide RFA, phase singularity (PS) mapping locates reentrant electrical waves (rotors) that perpetuate AF. The goal of this study was to test existing and develop new RFA strategies for terminating rotors identified with PS mapping. It is unsafe to test experimental RFA strategies in patients, so they were evaluated in silico using a bilayer computer model of the human atria with persistent AF (pAF) electrical (ionic) and structural (fibrosis) remodeling...
2016: Frontiers in Physiology
Giulia Ottaviani, Ana Maria Segura, Indranee N Rajapreyar, Bihong Zhao, Rajko Radovancevic, Pranav Loyalka, Biswajit Kar, Igor Gregoric, L Maximilian Buja
BACKGROUND: Previous studies reported that left ventricular noncompaction (LVNC) is a cardiomyopathy, familial or sporadic, arising from arrest of the normal process of trabecular remodeling during embryonic development. The diagnosis is usually made by echocardiography, but to date, there has been little research on the occurrence and clinicopathological features of LVNC in the explanted hearts of orthotopic heart transplant (OHT) recipients. DESIGN: The clinical, echocardiographic, and pathologic findings were reviewed for evidence of LVNC, diagnosed by echocardiographic criteria, in 105 patients with end-stage heart failure (HF) undergoing OHT...
July 2016: Cardiovascular Pathology: the Official Journal of the Society for Cardiovascular Pathology
Xinrong Fan, Chao Wang, Na Wang, Xianhong Ou, Hanxiong Liu, Yan Yang, Xitong Dang, Xiaorong Zeng, Lin Cai
Acehytisine, a multi-ion channel blocker, can markedly inhibit INa, ICa, IKur, If at various concentrations and effectively terminate and prevent atrial fibrillation (AF) in patients and animal models, but the molecular mechanism underlying its blockage remains elusive. In this study, we investigated the effects of acehytisine on action potentials and sodium channels of atrial and ventricular myocytes isolated from rabbit, using whole-cell recording system. We found that acehytisine exerted stronger blocking effects on sodium channels in atria than in ventricles, especially at depolarization (IC50: 48...
April 6, 2016: Journal of Pharmacological Sciences
Faquan Liang, Peidong Fan, Jessie Jia, Suya Yang, Zhan Jiang, Serge Karpinski, Dmytro Kornyeyev, Nikos Pagratis, Luiz Belardinelli, Lina Yao
AIMS: Increases in late Na(+) current (late INa) and activation of Ca(2+)/calmodulin-dependent protein kinase (CaMKII) are associated with atrial arrhythmias. CaMKII also phosphorylates Nav1.5, further increasing late INa. The combination of a CaMKII inhibitor with a late INa inhibitor may be superior to each compound alone to suppress atrial arrhythmias. Therefore, we investigated the effect of a CaMKII inhibitor in combination with a late INa inhibitor on anemone toxin II (ATX-II, a late INa enhancer)-induced atrial arrhythmias...
May 2016: Journal of Molecular and Cellular Cardiology
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