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atrial fibrillation immunohistochemistry structural morphological

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
Natalia Smorodinova, Lucie Lantová, Martin Bláha, Vojtěch Melenovský, Jan Hanzelka, Jan Pirk, Josef Kautzner, Tomáš Kučera
One of the generally recognized factors contributing to the initiation and maintenance of atrial fibrillation (AF) is structural remodeling of the myocardium that affects both atrial cardiomyocytes as well as interstitium. The goal of this study was to characterize morphologically and functionally interstitium of atria in patients with AF or in sinus rhythm (SR) who were indicated to heart surgery. Patient population consisted of 46 subjects (19 with long-term persistent AF, and 27 in SR) undergoing coronary bypass or valve surgery...
2015: PloS One
Xule Wang, Congxin Huang, Qingyan Zhao, He Huang, Yanhong Tang, Zixuan Dai, Xiaozhan Wang, Zongwen Guo, Jinping Xiao
AIMS: The aim of the present study was to explore the effect of renal sympathetic denervation (RSD) on the progression of paroxysmal atrial fibrillation (AF) in canines with long-term intermittent atrial pacing. METHODS AND RESULTS: Nineteen beagles were randomly divided into sham-operated group (six dogs), control group (six dogs), and RSD group (seven dogs). Sham-operated group were implanted with pacemakers without pacing; control group were implanted with pacemakers with long-term intermittent atrial pacing; and RSD group underwent catheter-based RSD bilaterally and were simultaneously implanted with pacemakers...
April 2015: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
Xian-zhi He, Hai-yu Wang, Yan Shen, Qing-hua Zhong, Sheng-xian Fang, Wen-jun Peng, Jian-fang Xue
BACKGROUND: This study aimed to discover the pathogenesis of focal atrial fibrillation (AF) originating from pulmonary veins by observing the histological structure and special cells in the canine pulmonary vein model of persistent atrial fibrillation. METHODS: The pulmonary veins and the sinus node were obtained from 10 mongrel dogs (5 AF and 5 control group). Light microscopy, transmission electron microscopy, and immunohistochemistry were applied to transverse sections of each pulmonary vein and sinoatrial node...
September 2012: Journal of Cardiology
Aras Puodziukynas, Tomas Kazakevicius, Raimundas Vaitkevicius, Kristina Rysevaite, Marius Jokubauskas, Inga Saburkina, Vaiva Sladkeviciute-Dirzinauskiene, Evaldas Dirzinauskas, Vytautas Zabiela, Vytautas Sileikis, Jurgita Plisiene, Neringa Pauziene, Remigijus Zaliunas, José Jalife, Dainius H Pauza
BACKGROUND: In treatment of atrial fibrillations (AF), radiofrequency ablation (RFA) at the pulmonary vein (PV) roots isolates AF triggers in the myocardial sleeves, but also can destroy PV ganglia and branches of the intrinsic cardiac nerve plexus. AIM: To determine the long-term impact of RFA at the PV roots on the structure of epicardial nerves located distally from the RFA site. METHODS: Five black-faced sheep underwent epicardial RFA of the left and middle PV roots...
April 3, 2012: Autonomic Neuroscience: Basic & Clinical
Domenico Corradi, Sergio Callegari, Roberta Maestri, David Ferrara, Domenica Mangieri, Rossella Alinovi, Paola Mozzoni, Silvana Pinelli, Matteo Goldoni, Ylenia Adelaide Privitera, Veronica Bartoli, Ettore Astorri, Emilio Macchi, Augusto Vaglio, Stefano Benussi, Ottavio Alfieri
INTRODUCTION: Atrial fibrillation (AF) in mitral regurgitation (MR) is a complex disease where multiple factors may induce left-atrial structural remodeling (SR). We explored the differential SR of the left-atrial posterior wall (LAPW) of patients affected by MR with or without persistent AF, and the expression of key proteins involved in its pathogenesis. METHODS AND RESULTS: Light microscopy of LAPW samples from 27 patients with MR and persistent AF (group 1), 33 with MR in sinus rhythm (group 2), and 15 autopsy controls (group 3) was used to measure myocyte diameter, percentage of myocytolytic myocytes, interstitial fibrosis, and capillary density; RT-PCR and Western blotting were used to assess the mRNA and protein levels of SOD-1, SOD-2, HO-1, calpain, MMP-2, MMP-9, TIMP-1, TIMP-2, and VEGF; immunofluorescence was used to locate these proteins...
March 2012: Journal of Cardiovascular Electrophysiology
Joseph S Ulphani, Rishi Arora, Jack H Cain, Roger Villuendas, Sharon Shen, David Gordon, Firdous Inderyas, Laura A Harvey, Alexander Morris, Jeffrey J Goldberger, Alan H Kadish
The objective of the study was to investigate the morphology, distribution, and electrophysiological profile of the autonomic fibers that innervate the ligament of Marshall (LOM). Gross anatomical dissections were performed in 10 dogs. Sections of the left vagus nerve, left stellate ganglion, and the LOM were immunostained to identify adrenergic and cholinergic nerves. Hearts were also stained for acetylcholinesterase to identify epicardial cholinergic nerves. In vivo electrophysiological studies were performed in another 10 dogs before and after LOM ablation...
September 2007: American Journal of Physiology. Heart and Circulatory Physiology
Vicente Climent, Aquilino Hurlé, Siew Yen Ho, Javier Sáenz-Santamaría, Agustín G Nogales, Damián Sánchez-Quintana
INTRODUCTION: The aim of this study was to investigate the early qualitative and quantitative structural changes in the left atrial wall after endocardial microwave ablation in patients with chronic atrial fibrillation (AF) undergoing mitral surgery. METHODS AND RESULTS: Seven patients with chronic AF of for at least 6 months underwent surgical microwave energy ablation. Linear isolation of pulmonary veins was performed in all patients by microwave energy applications to the endocardial surface delivered by catheter at 65-W constant power for 45 seconds...
November 2004: Journal of Cardiovascular Electrophysiology
Christian Weiss, Andreas Gocht, Stephan Willems, Matthias Hoffmann, Tim Risius, Thomas Meinertz
Focal AF is frequently triggered by ectopic beats mostly originating from the pulmonary veins (PVs). So far, the morphological substrate for this entity is not well defined. Therefore, the distribution of myocardial cells within the PV were examined as potential target sites for RF application. The PVs (118) of 30 human autopsied hearts (age of death 63 +/- 13 years, 17 men) were dissected in their complete circumference starting 1 cm from the ostium. Tissue sections of the PV were stained with hematoxylin-eosin and with Masson's trichrome...
September 2002: Pacing and Clinical Electrophysiology: PACE
Sander Verheule, Emily E Wilson, Rishi Arora, Steven K Engle, Luis R Scott, Jeffrey E Olgin
OBJECTIVE: Rapid electrical activity in pulmonary veins (PVs) has been proposed as a mechanism for focal atrial fibrillation. The way in which the myocardial sleeve inside PVs can form a substrate for focal activity is not well understood. Therefore, we have studied tissue structure and connexin distribution at the veno-atrial transition in the dog. METHODS: In adult mongrel dogs, the anatomy of the PV area was studied. Tissue structure in individual veins was assessed in formalin fixed sections using Masson's Trichrome staining...
September 2002: Cardiovascular Research
H I Yeh, Y J Lai, S H Lee, Y N Lee, Y S Ko, S A Chen, N J Severs, C H Tsai
BACKGROUND: The myocardial sleeve of the superior vena cava (SVC) has been identified as a potential initiating focus in atrial fibrillation, but information on cell-to-cell linkage at this site is lacking. METHODS AND RESULTS: We examined the SVC in 8 dogs by immunoconfocal and electron microscopy. Cardiomyocytes outlined with vinculin and bearing striations positive for alpha-actinin are found in the proximal segment of the SVC. These cells, grouped in bundles of various orientations according to location, extend cephalically as far as 3 cm from the right atrium (RA)-SVC junction...
December 18, 2001: Circulation
J Ausma, M Wijffels, G van Eys, M Koide, F Ramaekers, M Allessie, M Borgers
Chronic atrial fibrillation was induced in goats by electrical pacing. After 9 to 23 weeks of sustained atrial fibrillation, the morphology of the atrial structures was examined. The majority of the cardiomyocytes exhibited marked changes in their cellular substructures, with the replacement of sarcomeres by glycogen as the main characteristic. Using immuno-histochemical staining procedures, we assessed the expression and organization of contractile and cytoskeletal proteins in these cases and compared them with the expression and organization of these proteins in normal atria...
October 1997: American Journal of Pathology
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