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isolated atria

Shiwei Huang, Binglin Pan, He Zou, Wei Lin
BACKGROUND: Atrial fibrillation (AF) usually originates from pulmonary veins (PVs) but can also be caused by pulmonary veins outside, such as the coronary sinus (CS), the superior vena cava (SVC), and the ligament of Marshall. CASE PRESENTATION: A 69-year-old male with a history of palpitations for 10 years was referred to our institute because of its recurrence for half a day. A dynamic electrocardiogram revealed sinus rhythm (SR) and paroxysmal AF. Echocardiography demonstrated normal cardiac structure, and physical examination results were unremarkable...
March 13, 2018: BMC Cardiovascular Disorders
Espeed Khoshbin, Stephan Schueler
Explantation of a left ventricular assist device (LVAD) may be challenging even in the most experienced hands. We aim to describe the technique for explantation of an LVAD together with the heart as applicable to all contemporary implantable mechanical assist devices. In order to ensure safe explantation, particular care must be taken at three distinct stages: at the time of LVAD implantation, at pre-transplant assessment and at the time of heart transplantation. The preparation for a safe explantation at LVAD implantation includes positioning the driveline and the outflow graft away from the back of the sternum to ensure protection from injury during re-entry into the chest...
January 2018: Annals of Cardiothoracic Surgery
Mahya Najjari, Gholamhassan Vaezi, Vida Hojati, Zahra Mousavi, Azam Bakhtiarian, Vahid Nikoui
PURPOSE: Evidence show that statins possess wide beneficial cardioprotective and anti-inflammatory effects; therefore, in the present experiment, we investigated the antiarrhythmic properties of atorvastatin in ouabain-induced arrhythmia in isolated rat atria and the role of several inflammatory cytokines in this effect. MATERIALS AND METHODS: Male rats were pretreated with either of atorvastatin (10 mg/kg) or vehicle, orally once daily for 6 weeks. After induction of anesthesia, we isolated the atria and after incubation with ouabain, time of onset of arrhythmia and asystole as well as atrial beating rate and contractile force were recorded...
February 28, 2018: Immunopharmacology and Immunotoxicology
Silvia Carta, Andrea Kaelin Agten, Chiara Belcaro, Amarnath Bhide
OBJECTIVE: To quantify survival and neurodevelopmental outcome of fetuses with prenatally detected isolated severe bilateral ventriculomegaly form published literature. METHODS: Medline, Embase and the Cochrane Library were searched electronically. Only cases with prenatal diagnosis of apparently isolated severe ventriculomegaly and postnatal neurodevelopment assessment were selected and included. Severe ventriculomegaly was defined by the authors as enlargement of the ventricular atria, with a diameter greater than 15 mm on the transventricular plane while all cases where the investigators were unable to detect associated structural abnormality, chromosomal abnormality or fetal infections, and regarded the ventriculomegaly to be apparently isolated were included...
February 26, 2018: Ultrasound in Obstetrics & Gynecology
Juliano Q D Rodrigues, Henrique Camara, Aron Jurkiewicz, Rosely O Godinho
Hypertension is a risk factor for cardiovascular diseases, which have been associated with dysfunction of sympathetic and purinergic neurotransmission. Therefore, herein, we evaluated whether modifications of adenosine receptor signaling may contribute to the cardiac dysfunction observed in hypertension. Isolated right atria from spontaneously hypertensive (SHR) or normotensive Wistar rats (NWR) were used to investigate the influence of adenosine receptor signaling cascade in the cardiac chronotropism. Our results showed that adenosine, the endogenous agonist of adenosine receptors, and CPA, a selective agonist of A1 receptor, decreased the atrial chronotropism of NWR and SHR in a concentration- and time-dependent manner, culminating in cardiac arrest (0 bpm)...
February 22, 2018: Naunyn-Schmiedeberg's Archives of Pharmacology
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
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
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
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
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
Andres Enriquez, Jackson J Liang, Pasquale Santangeli, Francis E Marchlinski, Michael P Riley
We report the case of a 66 year-old male who underwent catheter ablation for drug-refractory paroxysmal atrial fibrillation (AF) at our institution. Radiofrequency catheter ablation was performed using a three-dimensional electroanatomical mapping system. During ablation of the pulmonary veins (PV), right atrial ectopics were noted to repeatedly trigger AF and atrial tachycardia (AT). After PV isolation, mapping of the right atrium revealed that the superior vena cava (SVC) was in AF, while both atria were in an organized AT...
April 2017: Journal of Atrial Fibrillation
Zahra Maria, Véronique A Lacombe
The biotinylated photolabeling assay enables quantification of cell-surface glucose transporters (GLUTs). This technique has been successfully applied to quantify the cell-surface GLUT protein content in striated muscles and adipose tissue, as a means to evaluate GLUT trafficking. Here, we describe the detailed method of quantifying the cell-surface content of several GLUT isoforms (1, 4, 8, and 12) in isolated cardiac myocytes, as well as in the intact perfused atria and ventricle.
2018: Methods in Molecular Biology
Richard Petersson, J Gustav Smith, David A Larsson, Öyvind Reitan, Jonas Carlson, Pyotr Platonov, Fredrik Holmqvist
BACKGROUND: It has previously been shown that the morphology of the P-wave neither depends on atrial size in healthy subjects with physiologically enlarged atria nor on the physiological anatomical variation in transverse orientation of the left atrium. The present study aimed to investigate if different pressures in the left and right atrium are associated with different P-wave morphologies. METHODS: 38 patients with isolated, increased left atrial pressure, 51 patients with isolated, increased right atrial pressure and 76 patients with biatrially increased pressure were studied...
December 6, 2017: BMC Cardiovascular Disorders
Hoang Thi Ai Phuong, Lamei Yu, Byung Mun Park, Suhn Hee Kim
Angiotensin II (Ang II) is metabolized from N-terminal by aminopeptidases and from C-terminal by Ang converting enzyme (ACE) to generate several truncated angiotensin peptides (Angs). The truncated Angs have different biological effects but it remains unknown whether Ang-(4-8) is an active peptide. The present study was to investigate the effects of Ang-(4-8) on hemodynamics and atrial natriuretic peptide (ANP) secretion using isolated beating rat atria. Atrial stretch caused increases in atrial contractility by 60% and in ANP secretion by 70%...
November 2017: Korean Journal of Physiology & Pharmacology
Annette Ebner, Nadine Kuerbis, Aljoscha Brandt, Birgit Zatschler, Sönke Weinert, David M Poitz, Bernd Ebner, Antje Augstein, Carsten Wunderlich, Ali El-Armouche, Ruth H Strasser
BACKGROUND: Caveolin-1 (Cav1)-/- mice display impaired development of left ventricular pressure and increased left ventricular wall thickness but no dilated ventricle; these are typical findings in patients with heart failure with preserved ejection fraction (HfpEF). Aiming to clarify if dysfunctional endothelial nitric oxide synthase (eNOS) influences cardiomyocyte contractility, cardiac conduction system, or afterload/vascular resistance, we studied Cav1-/- /eNOS-/- mice. METHODS: Cardiac function was assessed in vivo by pressure-volume-catheterization of the left ventricle, echocardiography and electrocardiography...
December 2017: Canadian Journal of Cardiology
Y Tian, S Zhou, Y H Yin, Y X Zheng, R P Wang, X Q Liu, Z Q Liu, Q F Liu, W Liu, J Pang, Z Jiang, L H Tian, J Huang, L Yang
Objective: To compare the value of two 3D imaging reconstruction methods for left atria and pulmonary vein on guiding the catheter ablation for atrial fibrillation (AF). Methods: From January 2014 to January 2017, a total of 100 drug refractory paroxysmal AF patients were divided into left atria direct angiography group (n=50), and indirect angiography group (n=50). 3D CARTO system was applied for mapping and guiding the ablation procedure. Patients assigned to direct angiography group were treated as follows: intraoperative puncture of atrial septum, inject contrast agent directly into the left atrium, conduct left atrial and pulmonary venous rotation angiography, reconstruct three-dimensional image, integrate the image into real-time X-ray system to facilitate circumferential pulmonary vein isolation...
November 24, 2017: Zhonghua Xin Xue Guan Bing za Zhi
Raoul Bacquelin, Raphaël P Martins, Nathalie Behar, Vincent Galand, Baptiste Polin, Jonathan Lacaze, Frédéric Sebag, Christophe Leclercq, Jean-Claude Daubert, Philippe Mabo, Dominique Pavin
BACKGROUND: Atrial fibrillation ablation is often performed by achieving pulmonary vein isolation using the "wide antral circumferential ablation" (WACA) technique, but many pulmonary veins remain connected because of conduction gaps in the ablation line. AIM: To analyse the efficacy of a novel technique based on pacing manoeuvres to detect gaps in an initial WACA lesion. METHODS: Patients referred for radiofrequency atrial fibrillation ablation were enrolled prospectively...
November 10, 2017: Archives of Cardiovascular Diseases
Rexson Tse, Jack Garland, Kilak Kesha, Yvonne Triggs, Lucy Modahl, David Milne, Zhi Yap, Simon Stables
Acute myocarditis is a potentially fatal cardiac pathology that is thought to cause sudden death through arrhythmia and cardiac failure. Of the different subtypes, lymphocytic myocarditis is the most common form. The pathophysiology of myocarditis can be generally diffuse or focally involve the ventricles, but less frequently affects the atria. Although the clinical literature reports isolated atrial myocarditis as a cause of atrial fibrillation and enlargement, there is scant postmortem literature on the findings of this pathology...
November 9, 2017: American Journal of Forensic Medicine and Pathology
Romina Hermann, Victoria Evangelina Mestre Cordero, María de Las Mercedes Fernández Pazos, Federico Joaquín Reznik, Débora Elisabet Vélez, Enrique Alberto Savino, María Gabriela Marina Prendes, Alicia Varela
AMP-activated protein kinase (AMPK) is a serine-threonine kinase that functions primarily as a metabolic sensor to coordinate anabolic and catabolic processes in the cell, via phosphorylation of multiple proteins involved in metabolic pathways, aimed to re-establish energy homeostasis at a cell-autonomous level. Myocardial ischemia and reperfusion represents a metabolic stress situation for myocytes. Whether AMPK plays a critical role in the metabolic and functional responses involved in these conditions remains uncertain...
October 14, 2017: Pflügers Archiv: European Journal of Physiology
Ayşe Barutcigil, Arda Tasatargil
BACKGROUND: This study aimed to examine the effects of nesfatin-1 on thoracic aorta vasoreactivity and to investigate the inotropic and chronotropic effects of nesfatin-1 on the spontaneous contractions of the isolated rat atria. METHODS: Isolated right atria and thoracic aorta were used in organ baths. The reactivity of the thoracic aorta was evaluated by potassium chloride (KCl), phenylephrine (Phe), acetylcholine (ACh), and sodium nitroprusside (SNP). The effects of nesfatin-1 on the spontaneous contractions of the rat atria were also examined...
October 13, 2017: Clinical and Experimental Hypertension: CHE
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