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Halfmann MC, Hopman LHGA, Körperich H, Blaszczyk E, Gröschel J, Schulz-Menger J, Salatzki J, André F, Friedrich S, Emrich T. Reproducibility assessment of rapid strains in cardiac MRI: Insights and recommendations for clinical application. Eur J Radiol 2024; 174:111386. [PMID: 38447431 DOI: 10.1016/j.ejrad.2024.111386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 02/15/2024] [Accepted: 02/19/2024] [Indexed: 03/08/2024]
Abstract
PURPOSE Studies have shown the incremental value of strain imaging in various cardiac diseases. However, reproducibility and generalizability has remained an issue of concern. To overcome this, simplified algorithms such as rapid atrioventricular strains have been proposed. This multicenter study aimed to assess the reproducibility of rapid strains in a real-world setting and identify potential predictors for higher interobserver variation. METHODS A total of 4 sites retrospectively identified 80 patients and 80 healthy controls who had undergone cardiac magnetic resonance imaging (CMR) at their respective centers using locally available scanners with respective field strengths and imaging protocols. Strain and volumetric parameters were measured at each site and then independently re-evaluated by a blinded core lab. Intraclass correlation coefficients (ICC) and Bland-Altman plots were used to assess inter-observer agreement. In addition, backward multiple linear regression analysis was performed to identify predictors for higher inter-observer variation. RESULTS There was excellent agreement between sites in feature-tracking and rapid strain values (ICC ≥ 0.96). Bland-Altman plots showed no significant bias. Bi-atrial feature-tracking and rapid strains showed equally excellent agreement (ICC ≥ 0.96) but broader limits of agreement (≤18.0 % vs. ≤3.5 %). Regression analysis showed that higher field strength and lower temporal resolution (>30 ms) independently predicted reduced interobserver agreement for bi-atrial strain parameters (ß = 0.38, p = 0.02 for field strength and ß = 0.34, p = 0.02 for temporal resolution). CONCLUSION Simplified rapid left ventricular and bi-atrial strain parameters can be reliably applied in a real-world multicenter setting. Due to the results of the regression analysis, a minimum temporal resolution of 30 ms is recommended when assessing atrial deformation.
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Affiliation(s)
- Moritz C Halfmann
- Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Rhine-Main, Germany
| | - Luuk H G A Hopman
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Cardiovascular Sciences, De Boelelaan 1118, 1081 HV Amsterdam, the Netherlands.
| | - Hermann Körperich
- Institute for Radiology, Nuclear Medicine and Molecular Imaging, Heart and Diabetes Center NRW, Ruhr-University of Bochum, 32545 Bad Oeynhausen, Germany.
| | - Edyta Blaszczyk
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Working Group on Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max Delbrueck Center for Molecular Medicine, Lindenberger Weg 80, Berlin 13125, Germany; German Center for Cardiovascular Research (DZHK), Partner Site, Berlin, Germany.
| | - Jan Gröschel
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Working Group on Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max Delbrueck Center for Molecular Medicine, Lindenberger Weg 80, Berlin 13125, Germany; German Center for Cardiovascular Research (DZHK), Partner Site, Berlin, Germany.
| | - Jeanette Schulz-Menger
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Working Group on Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max Delbrueck Center for Molecular Medicine, Lindenberger Weg 80, Berlin 13125, Germany; German Center for Cardiovascular Research (DZHK), Partner Site, Berlin, Germany.
| | - Janek Salatzki
- Department of Cardiology, Angiology, Pneumology, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69121 Heidelberg, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg-Mannheim, Germany.
| | - Florian André
- Department of Cardiology, Angiology, Pneumology, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69121 Heidelberg, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg-Mannheim, Germany.
| | | | - Tilman Emrich
- Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Rhine-Main, Germany.
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Chen J, Bendowski KT, Bizanti A, Zhang Y, Ma J, Hoover DB, Gozal D, Shivkumar K, Cheng ZJ. Distribution and morphology of calcitonin gene-related peptide (CGRP) innervation in flat mounts of whole rat atria and ventricles. Auton Neurosci 2024; 251:103127. [PMID: 38211380 DOI: 10.1016/j.autneu.2023.103127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 10/10/2023] [Accepted: 10/19/2023] [Indexed: 01/13/2024]
Abstract
Calcitonin gene-related peptide (CGRP) is widely used as a marker for nociceptive afferent axons. However, the distribution of CGRP-IR axons has not been fully determined in the whole rat heart. Immunohistochemically labeled flat-mounts of the right and left atria and ventricles, and the interventricular septum (IVS) in rats for CGRP were assessed with a Zeiss imager to generate complete montages of the entire atria, ventricles, and septum, and a confocal microscope was used to acquire detailed images of selected regions. We found that 1) CGRP-IR axons extensively innervated all regions of the atrial walls including the sinoatrial node region, auricles, atrioventricular node region, superior/inferior vena cava, left pre-caval vein, and pulmonary veins. 2) CGRP-IR axons formed varicose terminals around individual neurons in some cardiac ganglia but passed through other ganglia without making appositions with cardiac neurons. 3) Varicose CGRP-IR axons innervated the walls of blood vessels. 4) CGRP-IR axons extensively innervated the right/left ventricular walls and IVS. Our data shows the rather ubiquitous distribution of CGRP-IR axons in the whole rat heart at single-cell/axon/varicosity resolution for the first time. This study lays the foundation for future studies to quantify the differences in CGRP-IR axon innervation between sexes, disease models, and species.
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Affiliation(s)
- Jin Chen
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816, USA.
| | - Kohlton T Bendowski
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816, USA.
| | - Ariege Bizanti
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816, USA
| | - Yuanyuan Zhang
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816, USA
| | - Jichao Ma
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816, USA
| | - Donald B Hoover
- Department of Biomedical Sciences, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
| | - David Gozal
- Office of the Dean, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25701, USA
| | - Kalyanam Shivkumar
- Department of Medicine, Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, University of California, Los Angeles, CA 90095, USA
| | - Zixi Jack Cheng
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816, USA.
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Mantini C, Corradi F, Ricci F, Jensen B, Tana C, Di Mascio V, Mastrodicasa D, Bucciarelli B, Procaccini L, Saba L, Marco Tana, Cademartiri F, De Caterina R. A highly-detailed anatomical study of left atrial auricle as revealed by in-vivo computed tomography. Heliyon 2023; 9:e20575. [PMID: 37842578 PMCID: PMC10568352 DOI: 10.1016/j.heliyon.2023.e20575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 09/19/2023] [Accepted: 09/29/2023] [Indexed: 10/17/2023] Open
Abstract
The left atrial auricle (LAA) is the main source of intracardiac thrombi, which contribute significantly to the total number of stroke cases. It is also considered a major site of origin for atrial fibrillation in patients undergoing ablation procedures. The LAA is known to have a high degree of morphological variability, with shape and structure identified as important contributors to thrombus formation. A detailed understanding of LAA form, dimension, and function is crucial for radiologists, cardiologists, and cardiac surgeons. This review describes the normal anatomy of the LAA as visualized through multiple imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI), and echocardiography. Special emphasis is devoted to a discussion on how the morphological characteristics of the LAA are closely related to the likelihood of developing LAA thrombi, including insights into LAA embryology.
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Affiliation(s)
- Cesare Mantini
- Department of Neuroscience, Imaging and Clinical Sciences, “G. D'Annunzio” University, Chieti, Italy
| | | | - Fabrizio Ricci
- Department of Neuroscience, Imaging and Clinical Sciences, “G. D'Annunzio” University, Chieti, Italy
- Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Bjarke Jensen
- Department of Medical Biology, Amsterdam Cardiovascular Sciences, Amsterdam University Medical Centres, Amsterdam, the Netherlands
| | - Claudio Tana
- Geriatrics Clinic, SS. Annunziata Hospital of Chieti, 66100, Chieti, Italy
| | - Valeria Di Mascio
- Department of Neuroscience, Imaging and Clinical Sciences, “G. D'Annunzio” University, Chieti, Italy
| | | | - Benedetta Bucciarelli
- Department of Pediatrics, Politechnic University of Marche, G. Salesi Children's Hospital, Ancona, Italy
| | | | - Luca Saba
- Department of Radiology, University Hospital of Cagliari, Cagliari, Italy
| | - Marco Tana
- Internal Medicine Unit and Department of Vascular Medicine and Cardiovascular Ultrasound, SS. Annunziata Hospital of Chieti, Italy
| | | | - Raffaele De Caterina
- Cardiology, University of Pisa and University Cardiology Division, Pisa University Hospital, Pisa, Italy
- Fondazione Villa Serena per la Ricerca, Città Sant’Angelo-Pescara, Italy
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4
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Wu L, Jiang Z, Meulendijks ER, Baylan U, Waas ISE, Bugiani M, Tuinman PR, Fronczek J, Heunks LMA, de Groot JR, van Rossum AC, Niessen HWM, Krijnen PAJ. Atrial inflammation and microvascular thrombogenicity are increased in deceased COVID-19 patients. Cardiovasc Pathol 2023; 64:107524. [PMID: 36649811 PMCID: PMC9839463 DOI: 10.1016/j.carpath.2023.107524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Histopathological studies have shown inflammation, cardiomyocyte injury, and microvascular thrombosis in the ventricular myocardium of patients with coronavirus disease 2019 (COVID-19). However, although atrial dysfunction is common in COVID-19, little is known about histopathological changes in the atria of the heart. We therefore analyzed inflammation, cardiomyocyte injury, and microvascular thrombogenicity in the atria of deceased patients with COVID-19. METHODS Atrial tissue was obtained from autopsied COVID-19 (n=16) patients and control patients (n=10) and analyzed using immunohistochemistry. The infiltration of CD45+ leukocytes, CD3+ T lymphocytes, CD68+ macrophages, MPO+ neutrophils, and Tryptase+ mast cells were quantified as well as cardiomyocyte damage and microvascular thrombosis. In addition, Tissue Factor (TF) and Factor XII (FXII) were quantified as markers of microvascular thrombogenicity. RESULTS The numbers of lymphocytes, macrophages, and neutrophils were significantly increased in the atrial myocardium and epicardial atrial adipose tissue of COVID-19 patients compared with the control group. This was accompanied by dispersed cardiomyocyte injury, the occasional presence of microvascular thrombosis, and an increased presence of TF and FXII in the microvascular endothelium. CONCLUSIONS Severe COVID-19 induces inflammation, cardiomyocyte injury, and microvascular thrombosis in the atria of the heart.
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Affiliation(s)
- Linghe Wu
- Department of Pathology, Amsterdam University Medical Centre (AUMC), Location VUmc, Amsterdam, The Netherlands; Amsterdam Cardiovascular Sciences, AUMC, Location VUmc, Amsterdam, The Netherlands; Department of Pathology, AUMC, location AMC, Amsterdam, The Netherlands.
| | - Zhu Jiang
- Department of Pathology, Amsterdam University Medical Centre (AUMC), Location VUmc, Amsterdam, The Netherlands; Amsterdam Cardiovascular Sciences, AUMC, Location VUmc, Amsterdam, The Netherlands; Department of Pathology, AUMC, location AMC, Amsterdam, The Netherlands
| | - Eva R Meulendijks
- Department of Cardiology, AUMC, location VUmc, Amsterdam, The Netherlands
| | - Umit Baylan
- Department of Pathology, AUMC, location AMC, Amsterdam, The Netherlands
| | - Ingeborg S E Waas
- Department of Pathology, AUMC, location AMC, Amsterdam, The Netherlands
| | - Marianna Bugiani
- Department of Pathology, Amsterdam University Medical Centre (AUMC), Location VUmc, Amsterdam, The Netherlands; Department of Pathology, AUMC, location AMC, Amsterdam, The Netherlands
| | - Pieter R Tuinman
- Department of Intensive Care Medicine, AUMC, location VUmc, Amsterdam, The Netherlands
| | - Judith Fronczek
- Department of Forensic Medicine, Victorian Institute of Forensic Medicine, Monash Monash University, Southbank, Victoria, Australia
| | - Leo M A Heunks
- Department of Intensive Care Medicine, AUMC, location VUmc, Amsterdam, The Netherlands
| | - Joris R de Groot
- Department of Cardiology, AUMC, location VUmc, Amsterdam, The Netherlands
| | | | - Hans W M Niessen
- Department of Pathology, Amsterdam University Medical Centre (AUMC), Location VUmc, Amsterdam, The Netherlands; Amsterdam Cardiovascular Sciences, AUMC, Location VUmc, Amsterdam, The Netherlands; Department of Pathology, AUMC, location AMC, Amsterdam, The Netherlands; Department of Cardiac Surgery, AUMC, location VUmc, Amsterdam, The Netherlands
| | - Paul A J Krijnen
- Department of Pathology, Amsterdam University Medical Centre (AUMC), Location VUmc, Amsterdam, The Netherlands; Amsterdam Cardiovascular Sciences, AUMC, Location VUmc, Amsterdam, The Netherlands; Department of Pathology, AUMC, location AMC, Amsterdam, The Netherlands
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Westaby JD, Zullo E, Bicalho LM, Anderson RH, Sheppard MN. Effect of sex, age and body measurements on heart weight, atrial, ventricular, valvular and sub-epicardial fat measurements of the normal heart. Cardiovasc Pathol 2023; 63:107508. [PMID: 36442703 DOI: 10.1016/j.carpath.2022.107508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/16/2022] [Accepted: 11/21/2022] [Indexed: 11/27/2022] Open
Abstract
AIMS Descriptive morphological studies of the normal heart are lacking. Previous autopsy studies have focused mainly on heart weight. We characterize the normal heart by providing normal dimensions of the atria, ventricles, valves and sub-epicardial fat, comparing the findings in terms of sex, age and body measurements. METHODS From 3602 referrals to our cardiovascular pathology unit, pathological criteria used for the classification of a morphologically normal heart were a weight of below 500 grams in males, and below 400 grams in females. Diseased hearts were excluded on anatomical and histological evaluation. RESULTS We diagnosed 1062 morphologically normal hearts. Mean age at death was 34±12, with a male predominance (701, 66%). Age was similar in females and males (35±13 vs 34±12). Females had a significantly lower heart weight (285±55 vs 374±64). Sex was an independent predictor of most measurements. The atrial and ventricular cavities were significantly larger in males. All ventricular measurements of muscle thickness were larger in males. All valvular circumferences were larger in males. In contrast, sub-epicardial fat was significantly thicker in females in 6 of 7 regions. This is the first study to provide a calculator to give expected values according to sex, age, height and weight. CONCLUSIONS Major differences between the sexes exist in the morphologically normal heart. These variations should be considered when assessing cardiac structure in imaging for risk stratification and diagnosis in the cardiomyopathies, as well as in treatment outcomes.
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Affiliation(s)
- Joseph David Westaby
- CRY Cardiovascular Pathology Unit, Cardiovascular Clinical Academic Group, Molecular and Clinical Sciences Research Institute, St. George's, University of London, London, United Kingdom.
| | - Emelia Zullo
- CRY Cardiovascular Pathology Unit, Cardiovascular Clinical Academic Group, Molecular and Clinical Sciences Research Institute, St. George's, University of London, London, United Kingdom
| | - Luciana Morais Bicalho
- CRY Cardiovascular Pathology Unit, Cardiovascular Clinical Academic Group, Molecular and Clinical Sciences Research Institute, St. George's, University of London, London, United Kingdom
| | - Robert Henry Anderson
- CRY Cardiovascular Pathology Unit, Cardiovascular Clinical Academic Group, Molecular and Clinical Sciences Research Institute, St. George's, University of London, London, United Kingdom
| | - Mary Noelle Sheppard
- CRY Cardiovascular Pathology Unit, Cardiovascular Clinical Academic Group, Molecular and Clinical Sciences Research Institute, St. George's, University of London, London, United Kingdom
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Halfmann MC, Altmann S, Schoepf UJ, Reichardt C, Hennermann JB, Kreitner KF, Kloeckner R, Hahn F, Dueber C, Varga-Szemes A, Kampmann C, Emrich T. Left atrial strain correlates with severity of cardiac involvement in Anderson-Fabry disease. Eur Radiol 2023; 33:2039-51. [PMID: 36322192 DOI: 10.1007/s00330-022-09183-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 08/08/2022] [Accepted: 09/19/2022] [Indexed: 02/17/2023]
Abstract
OBJECTIVES Cardiac involvement in Anderson-Fabry disease (AFD) results in myocardial lipid depositions. An early diagnosis can maximize therapeutic benefit. Thus, this study aims to investigate the potential of cardiac MRI (CMR) based parameters of left atrial (LA) function and strain to detect early stages of AFD. METHODS Patients (n = 58, age 40 (29-51) years, 31 female) with genetically proven AFD had undergone CMR including left ventricular (LV) volumetry, mass index (LVMi), T1, and late gadolinium enhancement, complemented by LA and LV strain measurements and atrial emptying fractions. Patients were stratified into three disease phases and compared to age and sex-matched healthy controls (HC, n = 58, age 41 [26-56] years, 31 female). RESULTS A total of 19 early-, 20 intermediate-, and 19 advanced-phase patients were included. LV and LA reservoir strain was significantly impaired in all AFD phases, including early disease (both p < 0.001). In contrast, LA volumetry, T1, and LVMi showed no significant differences between the early phase and HC (p > 0.05). In the intermediate phase, LVMi and T1 demonstrated significant differences. In advanced phase, all parameters except active emptying fractions differed significantly from HC. ROC curve analyses of early disease phases revealed superior diagnostic confidence for the LA reservoir strain (AUC 0.88, sensitivity 89%, specificity 75%) over the LV strain (AUC 0.82). CONCLUSIONS LA reservoir strain showed impairment in early AFD and significantly correlated with disease severity. The novel approach performed better in identifying early disease than the established approach using LVMi and T1. Further studies are needed to evaluate whether these results justify earlier initiation of therapy and help minimize cardiac complications. KEY POINTS • Parameters of left atrial function and deformation showed impairments in the early stages of Anderson-Fabry disease and correlated significantly with the severity of Anderson-Fabry disease. • Left atrial reservoir strain performed superior to ventricular strain in detecting early myocardial involvement in Anderson-Fabry disease and improved diagnostic accuracies of approaches already using ventricular strain. • Further studies are needed to evaluate whether earlier initiation of enzyme replacement therapy based on these results can help minimize cardiac complications from Anderson-Fabry disease.
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Smith CER, Pinali C, Eisner DA, Trafford AW, Dibb KM. Enhanced calcium release at specialised surface sites compensates for reduced t-tubule density in neonatal sheep atrial myocytes. J Mol Cell Cardiol 2022; 173:61-70. [PMID: 36038009 DOI: 10.1016/j.yjmcc.2022.08.360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/07/2022] [Accepted: 08/23/2022] [Indexed: 01/06/2023]
Abstract
Cardiac myocytes rely on transverse (t)-tubules to facilitate a rapid rise in calcium throughout the cell. However, despite their importance in triggering synchronous Ca2+ release, t-tubules are highly labile structures. They develop postnatally, increase in density during exercise training and are lost in diseases such as heart failure (HF). In the majority of settings, an absence of t-tubules decreases function. Here we show that despite reduced t-tubule density due to immature t-tubules, the newborn atrium is highly specialised to maintain Ca2+ release. To compensate for fewer t-tubules triggering a central rise in Ca2+, Ca2+ release at sites on the cell surface is enhanced in the newborn, exceeding that at all Ca2+ release sites in the adult. Using electron and super resolution microscopy to investigate myocyte ultrastructure, we found that newborn atrial cells had enlarged surface sarcoplasmic reticulum and larger, more closely spaced surface and central ryanodine receptor clusters. We suggest that these adaptations mediate enhanced Ca2+ release at the sarcolemma and aid propagation to compensate for reduced t-tubule density in the neonatal atrium.
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Affiliation(s)
- Charlotte E R Smith
- Unit of Cardiac Physiology, Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, 3.14 Core Technology Facility, 46 Grafton Street, Manchester M13 9NT, United Kingdom
| | - Christian Pinali
- Unit of Cardiac Physiology, Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, 3.14 Core Technology Facility, 46 Grafton Street, Manchester M13 9NT, United Kingdom
| | - David A Eisner
- Unit of Cardiac Physiology, Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, 3.14 Core Technology Facility, 46 Grafton Street, Manchester M13 9NT, United Kingdom
| | - Andrew W Trafford
- Unit of Cardiac Physiology, Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, 3.14 Core Technology Facility, 46 Grafton Street, Manchester M13 9NT, United Kingdom
| | - Katharine M Dibb
- Unit of Cardiac Physiology, Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, 3.14 Core Technology Facility, 46 Grafton Street, Manchester M13 9NT, United Kingdom.
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Abstract
The cardiovascular system, consisting of the heart as the 'pump' and the vascular network of blood vessels, is responsible for the distribution of blood around the body. Oxygen molecules attach to haemoglobin in red blood cells and are transported around the body where the oxygen aids cellular metabolism. Any blockage in the blood vessels as a result of build-up of plaques in the endothelium layer would result in an interruption in blood supply and therefore oxygen deprivation (ischaemia). This would lead to necrosis of the distal area of the affected vessel and is known as an infarct. This article aims to describe the normal anatomy and physiology of the cardiovascular system and to explain some of the common associated disorders, with a brief guide to the management of a common heart disorder, myocardial infarction. A case study is included to enhance the knowledge of management of myocardial infarction. An in-depth knowledge and understanding of the cardiovascular system and its associated disorders will enable the nurse to safely assess a patient, recognise a deteriorating patient and seek early intervention.
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9
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O' Brien S, Holmes AP, Johnson DM, Kabir SN, O' Shea C, O' Reilly M, Avezzu A, Reyat JS, Hall AW, Apicella C, Ellinor PT, Niederer S, Tucker NR, Fabritz L, Kirchhof P, Pavlovic D. Increased atrial effectiveness of flecainide conferred by altered biophysical properties of sodium channels. J Mol Cell Cardiol 2022; 166:23-35. [PMID: 35114252 DOI: 10.1016/j.yjmcc.2022.01.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 01/13/2022] [Accepted: 01/26/2022] [Indexed: 11/25/2022]
Abstract
Atrial fibrillation (AF) affects over 1% of the population and is a leading cause of stroke and heart failure in the elderly. A feared side effect of sodium channel blocker therapy, ventricular pro-arrhythmia, appears to be relatively rare in patients with AF. The biophysical reasons for this relative safety of sodium blockers are not known. Our data demonstrates intrinsic differences between atrial and ventricular cardiac voltage-gated sodium currents (INa), leading to reduced maximum upstroke velocity of action potential and slower conduction, in left atria compared to ventricle. Reduced atrial INa is only detected at physiological membrane potentials and is driven by alterations in sodium channel biophysical properties and not by NaV1.5 protein expression. Flecainide displayed greater inhibition of atrial INa, greater reduction of maximum upstroke velocity of action potential, and slowed conduction in atrial cells and tissue. Our work highlights differences in biophysical properties of sodium channels in left atria and ventricles and their response to flecainide. These differences can explain the relative safety of sodium channel blocker therapy in patients with atrial fibrillation.
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Affiliation(s)
- Sian O' Brien
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK
| | - Andrew P Holmes
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK; School of Biomedical Sciences, Institute of Clinical Sciences, University of Birmingham, Birmingham, UK
| | - Daniel M Johnson
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK; School of Life, Health and Chemical Sciences, The Open University, Walton Hall, Milton Keynes, UK
| | - S Nashitha Kabir
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK
| | - Christopher O' Shea
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK
| | - Molly O' Reilly
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK
| | - Adelisa Avezzu
- School of Biomedical Engineering & Imaging Sciences, Kings' College London, London, UK
| | - Jasmeet S Reyat
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK
| | - Amelia W Hall
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA 02129, USA; Cardiovascular Disease Initiative, The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Clara Apicella
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK
| | - Patrick T Ellinor
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA 02129, USA; Cardiovascular Disease Initiative, The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Steven Niederer
- School of Biomedical Engineering & Imaging Sciences, Kings' College London, London, UK
| | - Nathan R Tucker
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA 02129, USA; Cardiovascular Disease Initiative, The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Masonic Medical Research Institute, Utica, NY, 13501, USA
| | - Larissa Fabritz
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK; University Center of Cardiovascular Science, University Heart and Vascular Center UKE, Hamburg, Germany; Department of Cardiology, University Heart and Vascular Center UKE, Hamburg, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, Germany
| | - Paulus Kirchhof
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK; Department of Cardiology, University Heart and Vascular Center UKE, Hamburg, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, Germany
| | - Davor Pavlovic
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK.
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Bilal AS, Thuerauf DJ, Blackwood EA, Glembotski CC. Design and Production of Heart Chamber-Specific AAV9 Vectors. Methods Mol Biol 2022; 2573:89-113. [PMID: 36040589 DOI: 10.1007/978-1-0716-2707-5_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Adeno-associated virus serotype 9 (AAV9) is often used in heart research involving gene delivery due to its cardiotropism, high transduction efficiency, and little to no pathogenicity, making it highly applicable for gene manipulation, in vivo. However, current AAV9 technology is limited by the lack of strains that can selectively express and elucidate gene function in an atrial- and ventricular-specific manner. In fact, study of gene function in cardiac atria has been limited due to the lack of an appropriate tool to study atrial gene expression in vivo, hindering progress in the study of atrial-specific diseases such as atrial fibrillation, the most common cardiac arrhythmia in the USA.This chapter describes the method for the design and production of such chamber-specific AAV9 vectors, with the use of Nppa and Myl2 promoters to enhance atrial- and ventricular-specific expression. While several gene promoter candidates were considered and tested, Nppa and Myl2 were selected for use here because of their clearly defined regulatory elements that confer cardiac chamber-specific expression. Accordingly, Nppa (-425/+25) and Myl2 (-226/+36) promoter fragments are inserted into AAV9 vectors. The atrial- and ventricular-specific expression conferred by these new recombinant AAV9 was confirmed in a double-fluorescent Cre-dependent reporter mouse model. At only 450 and 262 base pairs of Nppa and Myl2 promoters, respectively, these AAV9 that drive chamber-specific AAV9 transgene expression address two major limitations of AAV9 technology, i.e., achieving chamber-specificity while maximizing space in the AAV genome for insertion of larger transgenes.
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Affiliation(s)
- Alina S Bilal
- Translational Cardiovascular Research Center and Department of Internal Medicine, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, USA
| | - Donna J Thuerauf
- Department of Cellular and Molecular Biology, San Diego State University, San Diego, CA, USA
| | - Erik A Blackwood
- Translational Cardiovascular Research Center and Department of Internal Medicine, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, USA
| | - Christopher C Glembotski
- Translational Cardiovascular Research Center and Department of Internal Medicine, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, USA.
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11
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Sahadevan P, Allen BG. Isolation and culture of adult murine cardiac atrial and ventricular fibroblasts and myofibroblasts. Methods 2021; 203:187-195. [PMID: 33838270 DOI: 10.1016/j.ymeth.2021.04.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 04/02/2021] [Accepted: 04/03/2021] [Indexed: 01/05/2023] Open
Abstract
Cardiac fibroblasts play a critical role in extracellular matrix homeostasis, wound healing, and cardiac interstitial fibrosis: the latter being a pathophysiological response to a chronic increase in afterload. Using a standard protocol to isolate cardiac fibroblasts and maintain them in their quiescent phenotype in vitro will enable a better understanding of cardiac fibroblast biology and their role in the response to profibrotic stimuli. Here, we describe an enzymatic method for isolating cardiac fibroblasts. The resulting cells are maintained on either a collagen-coated hydrogel-bound polystyrene (compliant) substrate or standard polystyrene culture dishes (non-compliant) to obtain quiescent fibroblasts and activated fibroblasts (myofibroblasts), respectively. Fibroblasts maintained on a non-compliant substrate developed a myofibroblast phenotype, in which the αSMA immunoreactivity was markedly elevated and incorporated into the stress fibers. In contrast, ventricular and atrial fibroblasts retain their quiescent phenotype for up to 3 passages when maintained on a compliant substrate. Hence, the methodology described herein provides a simple and reproducible way to isolate adult murine atrial and ventricular cardiac fibroblasts from a single animal and, by selecting a substrate with the appropriate compliance, examine the mediators of fibroblast activation or inactivation.
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Affiliation(s)
- Pramod Sahadevan
- Montreal Heart Institute, 5000 Belanger St., Montréal, Québec H1T 1C8, Canada.
| | - Bruce G Allen
- Montreal Heart Institute, 5000 Belanger St., Montréal, Québec H1T 1C8, Canada; Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec H3C 3J7, Canada; Department of Pharmacology and Physiology, Université de Montréal, Montréal, Québec H3C 3J7, Canada; Department of Medicine, Université de Montréal, Montréal, Québec H3C 3J7, Canada.
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12
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Shutoh F, Masuda T, Sasaki T, Takei Y. Anomalous atrium associated with persistent left superior vena cava. Anat Sci Int 2021; 96:572-576. [PMID: 33486696 DOI: 10.1007/s12565-021-00604-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 01/11/2021] [Indexed: 10/22/2022]
Abstract
Persistent left superior vena cava (PLSVC) is the most common venous anomaly with an incidence of 0.3-0.5% in the general population. Here, we report a rare case of PLSVC with anomalous atrium in a cadaver during the student's dissection session at the University of Tsukuba. In this case, the coronary sinus had merged with the right atrium to form an enlarged sac-like structure and received systemic venous flow including inflow from the PLSVC. The roof of the coronary sinus with the right atrium was thicker than that of the control cases. We further found that the distance between the sinoatrial node and the opening of the coronary sinus was slightly more than half of that in control cases. This variant appears interesting and is worth reporting for developmental and clinical consideration.
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Affiliation(s)
- Fumihiro Shutoh
- Department of Anatomy and Neuroscience, Faculty of Medicine, University of Tsukuba, Ibaraki, 305-8577, Japan
| | - Tomoyuki Masuda
- Department of Neurobiology, Faculty of Medicine, University of Tsukuba, Ibaraki, 305-8577, Japan. .,Department of Neurology, Faculty of Medicine, University of Tsukuba, Ibaraki, 305-8575, Japan.
| | - Tetsuya Sasaki
- Department of Anatomy and Neuroscience, Faculty of Medicine, University of Tsukuba, Ibaraki, 305-8577, Japan
| | - Yosuke Takei
- Department of Anatomy and Neuroscience, Faculty of Medicine, University of Tsukuba, Ibaraki, 305-8577, Japan.
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13
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Shah SN, Varghese RGB, Theodore S. Histopathological changes in the right atrial appendages triggering atrial fibrillation: A tertiary care center study. INDIAN J PATHOL MICR 2021; 64:464-468. [PMID: 34341254 DOI: 10.4103/ijpm.ijpm_371_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Background Atrial fibrillation(AF) is as an abnormal irregular rhythm with chaotic generation of electrical signals in the atria of the heart. Various studies in the West have proved that atrial substrates, like isolated atrial amyloidosis can trigger the development of atrial fibrillation. In India, these structural changes have been analyzed on autopsied hearts. Aim To determine the role of Atrial Amyloid as a substrate for Atrial fibrillation in ante mortem hearts. Methods and Results Atrial appendages were obtained from seventy five patients undergoing open heart surgery at a tertiary care hospital in south India. They were stained with Hematoxylin &Eosin, Masson's Trichrome and Congo red stains and were examined for myocarditis, fibrosis and amyloidosis, respectively. 30 (40%) patients were in AF. Amyloid deposits were seen in 3 cases. All the three were in AF and had undergone mitral valve replacement (MVR) (P<0.05). 2 out of the 3 amyloid-positive cases showed active myocarditis and severe scarring but there was no statistically significant correlation between these factors. Conclusion Amyloid and myocarditis, independently act as an arrythmogenic substrates in the development of atrial fibrillation and are also increasingly associated with female gender and MVR. We hypothesize that the amyloid deposits are due to isolated atrial amyloidosis as they were seen only in young individuals. Some patients in sinus rhythm (SR) had large left atria and myocarditis and probably are at a higher risk for developing AF. Hence, follow-up of these patients is required for prevention of severe organ damage and timely therapeutic intervention.
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Affiliation(s)
- Saloni Naresh Shah
- Department of Histopathology, Apollo Hospitals, Chennai, Tamil Nadu, India
| | - Renu G' Boy Varghese
- Department of Pathology, Pondicherry Institute of Medical Sciences, Kalapet, Puducherry, India
| | - Sanjay Theodore
- Department of Cardiovascular and Thoracic Surgery, Chettinad Health City, Chennai, Tamil Nadu, India
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Simard C, Magaud C, Adjlane R, Dupas Q, Sallé L, Manrique A, Bois P, Faivre JF, Guinamard R. TRPM4 non-selective cation channel in human atrial fibroblast growth. Pflugers Arch 2020; 472:1719-1732. [PMID: 33047172 DOI: 10.1007/s00424-020-02476-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 09/30/2020] [Accepted: 10/06/2020] [Indexed: 12/26/2022]
Abstract
Cardiac fibroblasts play an important role in cardiac matrix turnover and are involved in cardiac fibrosis development. Ca2+ is a driving belt in this phenomenon. This study evaluates the functional expression and contribution of the Ca2+-activated channel TRPM4 in atrial fibroblast phenotype. Molecular and electrophysiological investigations were conducted in human atrial fibroblasts in primary culture and in atrial fibroblasts obtained from wild-type and transgenic mice with disrupted Trpm4 gene (Trpm4-/-). A typical TRPM4 current was recorded on human cells (equal selectivity for Na+ and K+, activation by internal Ca2+, voltage sensitivity, conductance of 23.2 pS, inhibition by 9-phenanthrol (IC50 = 6.1 × 10-6 mol L-1)). Its detection rate was 13% on patches at days 2-4 in culture but raised to 100% on patches at day 28. By the same time, a cell growth was observed. This growth was smaller when cells were maintained in the presence of 9-phenanthrol. Similar cell growth was measured on wild-type mice atrial fibroblasts during culture. However, this growth was minimized on Trpm4-/- mice fibroblasts compared to control animals. In addition, the expression of alpha smooth muscle actin increased during culture of atrial fibroblasts from wild-type mice. This was not observed in Trpm4-/- mice fibroblasts. It is concluded that TRPM4 participates in fibroblast growth and could thus be involved in cardiac fibrosis.
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Affiliation(s)
- Christophe Simard
- Groupe Signalisation, Electrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, EA4650, GIP Cyceron, Université de Caen Normandie, Sciences D, Esplanade de la Paix, 14032, Caen Cedex 5, France
| | - Christophe Magaud
- Laboratoire Signalisation et Transports Ioniques Membranaires (STIM), Université de Poitiers, CNRS, Poitiers, France
| | - Racim Adjlane
- Groupe Signalisation, Electrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, EA4650, GIP Cyceron, Université de Caen Normandie, Sciences D, Esplanade de la Paix, 14032, Caen Cedex 5, France
| | - Quentin Dupas
- Groupe Signalisation, Electrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, EA4650, GIP Cyceron, Université de Caen Normandie, Sciences D, Esplanade de la Paix, 14032, Caen Cedex 5, France
| | - Laurent Sallé
- Groupe Signalisation, Electrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, EA4650, GIP Cyceron, Université de Caen Normandie, Sciences D, Esplanade de la Paix, 14032, Caen Cedex 5, France
| | - Alain Manrique
- Groupe Signalisation, Electrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, EA4650, GIP Cyceron, Université de Caen Normandie, Sciences D, Esplanade de la Paix, 14032, Caen Cedex 5, France
| | - Patrick Bois
- Laboratoire Signalisation et Transports Ioniques Membranaires (STIM), Université de Poitiers, CNRS, Poitiers, France
| | - Jean-François Faivre
- Laboratoire Signalisation et Transports Ioniques Membranaires (STIM), Université de Poitiers, CNRS, Poitiers, France
| | - Romain Guinamard
- Groupe Signalisation, Electrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, EA4650, GIP Cyceron, Université de Caen Normandie, Sciences D, Esplanade de la Paix, 14032, Caen Cedex 5, France.
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15
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Wang H, Varagic J, Nagata S, Kon ND, Ahmad S, VonCannon JL, Wright KN, Sun X, Deal D, Groban L, Ferrario CM. Differential Expression of the Angiotensin-(1-12)/Chymase Axis in Human Atrial Tissue. J Surg Res 2020; 253:173-84. [PMID: 32361612 DOI: 10.1016/j.jss.2020.03.051] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 02/25/2020] [Accepted: 03/30/2020] [Indexed: 12/17/2022]
Abstract
BACKGROUND Heart chymase rather than angiotensin (Ang)-converting enzyme has higher specificity for Ang I conversion into Ang II in humans. A new pathway for direct cardiac Ang II generation has been revealed through the demonstration that Ang-(1-12) is cleaved by chymase to generate Ang II directly. Herein, we address whether Ang-(1-12), chymase messenger RNA (mRNA), and activity levels can be differentiated in human atrial tissue from normal and diseased hearts and if these measures associate with various pathologic heart conditions. MATERIALS AND METHODS Atrial appendages were collected from 11 nonfailing donor hearts and 111 patients undergoing heart surgery for the correction of valvular heart disease, resistant atrial fibrillation, or ischemic heart disease. Chymase mRNA was analyzed by real-time polymerase chain reaction and enzymatic activity by high-performance liquid chromatography using Ang-(1-12) as the substrate. Ang-(1-12) levels were determined by immunohistochemical staining. RESULTS Chymase gene transcripts, chymase activity, and immunoreactive Ang-(1-12) expression levels were higher in left atrial tissue compared with right atrial tissue, irrespective of cardiac disease. In addition, left atrial chymase mRNA expression was significantly higher in stroke versus nonstroke patients and in cardiac surgery patients who had a history of postoperative atrial fibrillation versus nonatrial fibrillation. Correlation analysis showed that left atrial chymase mRNA was positively related to left atrial enlargement, as determined by echocardiography. CONCLUSIONS As Ang-(1-12) expression and chymase gene transcripts and enzymatic activity levels were positively linked to left atrial size in patients with left ventricular heart disease, an important alternate Ang II forming pathway, via Ang-(1-12) and chymase, in maladaptive atrial and ventricular remodeling in humans is uncovered.
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Abstract
OBJECTIVES To develop an adult guinea pig model of lipotoxicity and explore the underlying mechanisms associated with changes in the expression of the delayed rectifier potassium current (IK). BACKGROUND Lipotoxicity may represent a common link among metabolic disorders and a higher vulnerability to arrhythmias. METHODS Whole-cell patch clamp, and palmitic acid (PA, a potent inducer of lipotoxicity), were used to assess mechanisms of short-term (∼50 days) high-fat diet (HFD) feeding on atrial electrophysiology in guinea pig hearts and myocytes. RESULTS HFD fed guinea pigs were significantly heavier, displayed hypertriglyceridemia and hypercholesterolemia; but no signs of hyperglycemia or inflammation compared to low-fat diet fed controls. Increasing cardiac PA levels, resulted in shortened atrial action potential duration, and increased IK density. Inhibition of phosphoinositide 3-kinase (PI3K) prevented increases in IK due to PA. Acute (≥1hr) exposure of atrial myocytes to exogenous PA (1 mM) increased the density of the rapid delayed rectifier potassium current IKr, while it was decreased with the unsaturated oleic acid (OA, 1 mM). Serine-threonine protein phosphatase-2 (PP2A) inhibition with cantharidin reversed the effect of OA on IKr. CONCLUSION Our data provide evidence of a novel lipotoxic guinea pig model with signs of vulnerability to arrhythmias. Inhibition of PA/PI3K/IK and/or activation of the OA/PP2A/IKr pathways may be therapeutically beneficial for lipotoxic arrhythmias.
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Affiliation(s)
- Ademuyiwa S Aromolaran
- Cardiac Electrophysiology and Metabolism Research Group, VA New York Harbor Healthcare System, Research and Development Office, (151), 800 Poly Place, Brooklyn, NY, 11209, USA; Department of Cell Biology, State University of New York Downstate Medical Center, Brooklyn, NY, USA; Department of Physiology & Cellular Biophysics, Columbia University, New York, NY, USA.
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17
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Roney CH, Pashaei A, Meo M, Dubois R, Boyle PM, Trayanova NA, Cochet H, Niederer SA, Vigmond EJ. Universal atrial coordinates applied to visualisation, registration and construction of patient specific meshes. Med Image Anal 2019; 55:65-75. [PMID: 31026761 PMCID: PMC6543067 DOI: 10.1016/j.media.2019.04.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 03/07/2019] [Accepted: 04/15/2019] [Indexed: 11/26/2022]
Abstract
We introduce a coordinate system for the atria based on anatomical landmarks. We construct the coordinates from solutions to Laplace’s equation. We demonstrate the mapping of both scalar and vector data between different atria. The coordinate system was used for registration and 2D visualisation of multimodal data. Patient specific meshes with atrial structures and fibre direction were constructed using just five landmark points.
Integrating spatial information about atrial physiology and anatomy in a single patient from multimodal datasets, as well as generalizing these data across patients, requires a common coordinate system. In the atria, this is challenging due to the complexity and variability of the anatomy. We aimed to develop and validate a Universal Atrial Coordinate (UAC) system for the following applications: combination and assessment of multimodal data; comparison of spatial data across patients; 2D visualization; and construction of patient specific geometries to test mechanistic hypotheses. Left and right atrial LGE-MRI data were segmented and meshed. Two coordinates were calculated for each atrium by solving Laplace’s equation, with boundary conditions assigned using five landmark points. The coordinate system was used to map spatial information between atrial meshes, including scalar fields measured using different mapping modalities, and atrial anatomic structures and fibre directions from a reference geometry. Average error in point transfer from a source mesh to a destination mesh and back again was less than 0.1 mm for the left atrium and 0.02 mm for the right atrium. Patient specific meshes were constructed using the coordinate system and phase singularity density maps from arrhythmia simulations were visualised in 2D. In conclusion, we have developed a universal atrial coordinate system allowing automatic registration of imaging and electroanatomic mapping data, 2D visualisation, and patient specific model creation.
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Affiliation(s)
- Caroline H Roney
- School of Biomedical Engineering and Imaging Sciences, King's College London, United Kingdom.
| | - Ali Pashaei
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Pessac-Bordeaux, France; IMB Bordeaux Institute of Mathematics, University of Bordeaux, 351 cours de la Libération, Talence 33405, France
| | - Marianna Meo
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Pessac-Bordeaux, France; University of Bordeaux, CRCTB, U1045, Bordeaux, France; INSERM, CRCTB, U1045, Bordeaux, France
| | - Rémi Dubois
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Pessac-Bordeaux, France; University of Bordeaux, CRCTB, U1045, Bordeaux, France; INSERM, CRCTB, U1045, Bordeaux, France
| | | | | | - Hubert Cochet
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Pessac-Bordeaux, France
| | - Steven A Niederer
- School of Biomedical Engineering and Imaging Sciences, King's College London, United Kingdom
| | - Edward J Vigmond
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Pessac-Bordeaux, France; IMB Bordeaux Institute of Mathematics, University of Bordeaux, 351 cours de la Libération, Talence 33405, France
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18
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Shamsaldeen YA, Culliford L, Clout M, James AF, Ascione R, Hancox JC, Marrion NV. Role of SK channel activation in determining the action potential configuration in freshly isolated human atrial myocytes from the SKArF study. Biochem Biophys Res Commun 2019; 512:684-690. [PMID: 30922569 DOI: 10.1016/j.bbrc.2019.03.074] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 03/13/2019] [Indexed: 10/27/2022]
Abstract
Inhibition of SK channel function is being pursued in animal models as a possible therapeutic approach to treat atrial fibrillation (AF). However, the pharmacology of SK channels in human atria is unclear. SK channel function is inhibited by both apamin and UCL1684, with the former discriminating between SK channel subtypes. In this proof-of-principle study, the effects of apamin and UCL1684 on right atrial myocytes freshly isolated from patients in sinus rhythm undergoing elective cardiac surgery were investigated. Outward current evoked from voltage clamped human atrial myocytes was reduced by these two inhibitors of SK channel function. In contrast, membrane current underlying the atrial action potential was affected significantly only by UCL1684 and not by apamin. This pharmacology mirrors that observed in mouse atria, suggesting that mammalian atria possess two populations of SK channels, with only one population contributing to the action potential waveform. Immuno-visualization of the subcellular localization of SK2 and SK3 subunits showed a high degree of colocalization, consistent with the formation of heteromeric SK2/SK3 channels. These data reveal that human atrial myocytes express two SK channel subtypes, one exhibiting an unusual pharmacology. These channels contribute to the atrial action potential waveform and might be a target for novel therapeutic approaches to treat supraventricular arrhythmic conditions such as atrial fibrillation.
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Affiliation(s)
- Yousif A Shamsaldeen
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, BS8 1TD, UK
| | - Lucy Culliford
- Clinical Trials and Evaluation Unit, Bristol Trials Centre, Bristol Medical School, University of Bristol, Bristol, UK
| | - Madeleine Clout
- Clinical Trials and Evaluation Unit, Bristol Trials Centre, Bristol Medical School, University of Bristol, Bristol, UK
| | - Andrew F James
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, BS8 1TD, UK
| | - Raimondo Ascione
- Translational Biomedical Research Centre, Faculty of Health Sciences, University of Bristol, UK
| | - Jules C Hancox
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, BS8 1TD, UK
| | - Neil V Marrion
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, BS8 1TD, UK.
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Ballester-Rodés M, Carreras-Costa F, Versyp-Ducaju T, Ballester-Rodés M, Mehta D. Field dynamics in atrioventricular activation. Clinical evidence of a specific field-to-protein interaction. Med Hypotheses 2019; 124:56-59. [PMID: 30798917 DOI: 10.1016/j.mehy.2019.02.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 01/29/2019] [Accepted: 02/02/2019] [Indexed: 11/25/2022]
Abstract
The atrioventricular node (AV) is considered the electrical connection between the atria and ventricles. There is an electrical pause between activation of the atria and the ventricles (PR segment), but to date the mechanism responsible for this interruption remains unclear. The present communication focuses on the hypothesis that magnetic field dynamics could provide the answer. Proof of this hypothesis is that in Wolff-Parkinson-White syndrome, where there is physical connection between the atria and ventricles (bundle of Kent), there is electrical AV continuity, no PR segment is detected, and catheter ablation of the abnormal bundle restores AV discontinuity. Spontaneous initiation of the heart at the level of the sinus node, the pacemaker of the heart, could also be explained via field dynamics. The known transmembrane pacemaker protein CHN4, present in both sinoatrial and AV nodal cells, could interact with field information to provide specificity in an electronic key-to-lock mechanism interaction.
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Affiliation(s)
- Manel Ballester-Rodés
- Department of Medicine, Faculty of Medicine, University of Lleida, Catalunya, Spain.
| | - Francesc Carreras-Costa
- Cardiac Imaging Unit, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, CIBERCV, Spain
| | | | | | - Davendra Mehta
- Al Sabah Arrythmia Institute, Mount Sinai St. Luke's Hospital, New York, USA
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20
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Corrado C, Williams S, Karim R, Plank G, O'Neill M, Niederer S. A work flow to build and validate patient specific left atrium electrophysiology models from catheter measurements. Med Image Anal 2018; 47:153-163. [PMID: 29753180 PMCID: PMC5998385 DOI: 10.1016/j.media.2018.04.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 02/16/2018] [Accepted: 04/19/2018] [Indexed: 11/19/2022]
Abstract
Biophysical models of the atrium provide a physically constrained framework for describing the current state of an atrium and allow predictions of how that atrium will respond to therapy. We propose a work flow to simulate patient specific electrophysiological heterogeneity from clinical data and validate the resulting biophysical models. In 7 patients, we recorded the atrial anatomy with an electroanatomical mapping system (St Jude Velocity); we then applied an S1-S2 electrical stimulation protocol from the coronary sinus (CS) and the high right atrium (HRA) whilst recording the activation patterns using a PentaRay catheter with 10 bipolar electrodes at 12 ± 2 sites across the atrium. Using only the activation times measured with a PentaRay catheter and caused by a stimulus applied in the CS with a remote catheter we fitted the four parameters for a modified Mitchell-Schaeffer model and the tissue conductivity to the recorded local conduction velocity restitution curve and estimated local effective refractory period. Model parameters were then interpolated across each atrium. The fitted model recapitulated the S1-S2 activation times for CS pacing giving a correlation ranging between 0.81 and 0.98. The model was validated by comparing simulated activations times with the independently recorded HRA pacing S1-S2 activation times, giving a correlation ranging between 0.65 and 0.96. The resulting work flow provides the first validated cohort of models that capture clinically measured patient specific electrophysiological heterogeneity.
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Affiliation(s)
- Cesare Corrado
- Division of Imaging Sciences & Biomedical Engineering, King's College London, London SE17EH, United Kingdom.
| | - Steven Williams
- Division of Imaging Sciences & Biomedical Engineering, King's College London, London SE17EH, United Kingdom
| | - Rashed Karim
- Division of Imaging Sciences & Biomedical Engineering, King's College London, London SE17EH, United Kingdom
| | - Gernot Plank
- Department of Biophysics, Medical University of Graz, Neue Stiftingtalstraße 6/IV, 8010 Graz, Austria
| | - Mark O'Neill
- Division of Imaging Sciences & Biomedical Engineering, King's College London, London SE17EH, United Kingdom
| | - Steven Niederer
- Division of Imaging Sciences & Biomedical Engineering, King's College London, London SE17EH, United Kingdom
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21
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Rundqvist L, Engvall J, Faresjö M, Carlsson E, Blomstrand P. Regular endurance training in adolescents impacts atrial and ventricular size and function. Eur Heart J Cardiovasc Imaging 2018; 18:681-687. [PMID: 27406576 DOI: 10.1093/ehjci/jew150] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 06/23/2016] [Indexed: 12/24/2022] Open
Abstract
Aims The aims of the study were to explore the effects of long-term endurance exercise on atrial and ventricular size and function in adolescents and to examine whether these changes are related to maximal oxygen uptake (VO2max). Methods and results Twenty-seven long-term endurance-trained adolescents aged 13-19 years were individually matched by age and gender with 27 controls. All participants, 22 girls and 32 boys, underwent an echocardiographic examination at rest, including standard and colour tissue Doppler investigation. VO2max was assessed during treadmill exercise. All heart dimensions indexed for body size were larger in the physically active group compared with controls: left ventricular end-diastolic volume 60 vs. 50 mL/m2 (P <0.001), left atrial volume 27 vs. 19 mL/m2 (P < 0.001), and right ventricular (RV) and right atrial area 15 vs. 13 and 9 vs. 7 cm2/m2, respectively (P <0.001 for both). There were strong associations between the size of the cardiac chambers and VO2max. Further, we found improved systolic function in the active group compared with controls: left ventricular ejection fraction 61 vs. 59% (P= 0.036), tricuspid annular plane systolic excursion 12 vs. 10 mm/m2 (P= 0.008), and RV early peak systolic velocity s' 11 vs. 10 cm/s (P = 0.031). Conclusion Cardiac remodelling to long-term endurance exercise in adolescents is manifested by an increase in atrial as well as ventricular dimensions. The physically active group also demonstrated functional remodelling with an increase in TAPSE and systolic RV wall velocity. These findings have practical implications when assessing cardiac enlargement and function in physically active youngsters.
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Affiliation(s)
- Louise Rundqvist
- Department of Natural Science and Biomedicine, School of Health and Welfare, Jönköping University, P.O Box 1026, Jönköping SE-551 11, Sweden
| | - Jan Engvall
- Department of Clinical Physiology, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
- Centre for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
| | - Maria Faresjö
- Department of Natural Science and Biomedicine, School of Health and Welfare, Jönköping University, P.O Box 1026, Jönköping SE-551 11, Sweden
| | - Emma Carlsson
- Department of Natural Science and Biomedicine, School of Health and Welfare, Jönköping University, P.O Box 1026, Jönköping SE-551 11, Sweden
| | - Peter Blomstrand
- Department of Natural Science and Biomedicine, School of Health and Welfare, Jönköping University, P.O Box 1026, Jönköping SE-551 11, Sweden
- Department of Clinical Physiology, Region Jönköping County, Jönköping, Sweden
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22
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Maria Z, Lacombe VA. Quantification of Cell-Surface Glucose Transporters in the Heart Using a Biotinylated Photolabeling Assay. Methods Mol Biol 2018; 1713:229-40. [PMID: 29218529 DOI: 10.1007/978-1-4939-7507-5_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
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.
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23
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Goodrow RJ Jr, Desai S, Treat JA, Panama BK, Desai M, Nesterenko VV, Cordeiro JM. Biophysical comparison of sodium currents in native cardiac myocytes and human induced pluripotent stem cell-derived cardiomyocytes. J Pharmacol Toxicol Methods 2018; 90:19-30. [PMID: 29128504 DOI: 10.1016/j.vascn.2017.11.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 09/22/2017] [Accepted: 11/02/2017] [Indexed: 12/31/2022]
Abstract
INTRODUCTION Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are used for safety pharmacology and to investigate genetic diseases affecting cardiac ion channels. It is unclear whether adult myocytes or hiPSC-CMs are the better platform for cardiac safety pharmacology. We examined the biophysical and molecular properties of INa in adult myocytes and hiPSC-CMs. METHODS hiPSC-CMs were plated at low density. Atrial and ventricular cells were obtained from dog hearts. Whole cell patch clamp was used to record INa. RESULTS Voltage clamp recordings showed a large INa in all three cell types but different densities. Small differences in steady-state inactivation and recovery from inactivation were noted in the three cell types. Application of lidocaine to the three cell types showed a similar pattern of block of INa under voltage clamp; however, lidocaine produced different effects on AP waveform under current clamp. AP clamp experiments showed that application of ventricular or atrial cell waveforms to the same hiPSC-CM elicited a large INa while application of a sinoatrial node waveform elicited no INa. Molecular analysis of Na+ channel subunits showed SCN5A and SCN1B-4B were expressed in adult cells and iPSC-CMs. However, iPSC-CMs express both fetal (exon 6A) and adult (exon 6) isoforms of SCN5A. DISCUSSION There are major differences in INa density and smaller differences in other biophysical properties of INa in adult atrial, ventricular, and hiPSC-CMs. The depolarized maximum diastolic potential coupled with the presence of phase 4 depolarization limits the contribution of INa in hiPSC-CM action potentials. Our results suggest that hiPSC-CMs may be useful for drug screening of Na+ channel inhibitors under voltage clamp but not current clamp.
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Hermann R, Mestre Cordero VE, Fernández Pazos MDLM, Reznik FJ, Vélez DE, Savino EA, Marina Prendes MG, Varela A. Differential effects of AMP-activated protein kinase in isolated rat atria subjected to simulated ischemia-reperfusion depending on the energetic substrates available. Pflugers Arch 2017; 470:367-383. [PMID: 29032506 DOI: 10.1007/s00424-017-2075-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 09/24/2017] [Accepted: 09/28/2017] [Indexed: 12/31/2022]
Abstract
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. In this study, in order to gain a deeper insight into the role of endogenous AMPK activation during myocardial ischemia and reperfusion, we explored the effects of the pharmacological inhibition of AMPK on contractile function rat, contractile reserve, tissue lactate production, tissue ATP content, and cellular viability. For this aim, isolated atria subjected to simulated 75 min ischemia-75 min reperfusion (Is-Rs) in the presence or absence of the pharmacological inhibitor of AMPK (compound C) were used. Since in most clinical situations of ischemia-reperfusion the heart is exposed to high levels of fatty acids, the influence of palmitate present in the incubation medium was also investigated. The present results suggest that AMPK activity significantly increases during Is, remaining activated during Rs. The results support that intrinsic activation of AMPK has functional protective effects in the reperfused atria when glucose is the only available energetic substrate whereas it is deleterious when palmitate is also available. Cellular viability was not affected by either of these conditions.
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Affiliation(s)
- Romina Hermann
- Physiology Unit, Department of Biological Sciences, School of Pharmacy and Biochemistry, University of Buenos Aires and IQUIMEFA-CONICET, Junín, 956, Buenos Aires, Argentina.
| | - Victoria Evangelina Mestre Cordero
- Physiology Unit, Department of Biological Sciences, School of Pharmacy and Biochemistry, University of Buenos Aires and IQUIMEFA-CONICET, Junín, 956, Buenos Aires, Argentina
| | - María de Las Mercedes Fernández Pazos
- Physiology Unit, Department of Biological Sciences, School of Pharmacy and Biochemistry, University of Buenos Aires and IQUIMEFA-CONICET, Junín, 956, Buenos Aires, Argentina
| | - Federico Joaquín Reznik
- Physiology Unit, Department of Biological Sciences, School of Pharmacy and Biochemistry, University of Buenos Aires and IQUIMEFA-CONICET, Junín, 956, Buenos Aires, Argentina
| | - Débora Elisabet Vélez
- Physiology Unit, Department of Biological Sciences, School of Pharmacy and Biochemistry, University of Buenos Aires and IQUIMEFA-CONICET, Junín, 956, Buenos Aires, Argentina
| | - Enrique Alberto Savino
- Physiology Unit, Department of Biological Sciences, School of Pharmacy and Biochemistry, University of Buenos Aires and IQUIMEFA-CONICET, Junín, 956, Buenos Aires, Argentina
| | - María Gabriela Marina Prendes
- Physiology Unit, Department of Biological Sciences, School of Pharmacy and Biochemistry, University of Buenos Aires and IQUIMEFA-CONICET, Junín, 956, Buenos Aires, Argentina
| | - Alicia Varela
- Physiology Unit, Department of Biological Sciences, School of Pharmacy and Biochemistry, University of Buenos Aires and IQUIMEFA-CONICET, Junín, 956, Buenos Aires, Argentina
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Abstract
Aging plays a critical role in the genesis of atrial fibrillation (AF) and also increases the risks of cardiac dysfunction and stroke in AF patients. AF is caused by increased AF triggering from abnormalities of the thoracic vein and/or modulated substrate (atrial) with enhancement of AF maintenance. Clinical and laboratory evidence indicates that aging is significant in the creation of atrial electrical and structural remodeling that leads to increased susceptibility to AF occurrence. Aging is commonly associated with cardiovascular comorbidities, oxidative stress, calcium dysregulation, atrial myopathy with apoptosis, and fibrosis, which all contribute to the genesis of AF. This review updates the current understanding of the effects of aging on the pathophysiology of AF.
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Affiliation(s)
- Yung-Kuo Lin
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University.,Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University
| | - Yi-Ann Chen
- Division of Nephrology, Sijhih Cathay General Hospital
| | - Ting-I Lee
- Division of Endocrinology and Metabolism, Wan Fang Hospital, Taipei Medical University
| | - Yao-Chang Chen
- Department of Biomedical Engineering, National Defense Medical Center
| | - Shih-Ann Chen
- Division of Cardiology and Cardiovascular Research Center, Veterans General Hospital-Taipei
| | - Yi-Jen Chen
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University.,Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University
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26
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Abstract
Atrial fibrillation is the most common sustained arrhythmia and its prevalence is rapidly rising with the aging of the population. Cardiac alternans, defined as cyclic beat-to-beat alternations in contraction force, action potential (AP) duration and intracellular Ca2+ release at constant stimulation rate, has been associated with the development of ventricular arrhythmias. Recent clinical data also provide strong evidence that alternans plays a central role in arrhythmogenesis in atria. The aim of this article is to review the mechanisms that are responsible for repolarization alternans and contribute to the transition from spatially concordant alternans to the more arrhythmogenic spatially discordant alternans in atria.
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Affiliation(s)
- Giedrius Kanaporis
- Department of Physiology & Biophysics, Rush University Medical Center, Chicago, USA.
| | - Lothar A Blatter
- Department of Physiology & Biophysics, Rush University Medical Center, Chicago, USA
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Barajas-Martinez H, Goodrow RJ, Hu D, Patel P, Desai M, Panama BK, Treat JA, Aistrup GL, Cordeiro JM. Biophysical and molecular comparison of sodium current in cells isolated from canine atria and pulmonary vein. Pflugers Arch 2017; 469:703-712. [PMID: 28243733 DOI: 10.1007/s00424-017-1956-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 02/08/2017] [Accepted: 02/10/2017] [Indexed: 11/25/2022]
Abstract
The collar of the pulmonary vein (PV) is the focal point for the initiation of atrial arrhythmias, but the mechanisms underlying how PV cells differ from neighboring left atrial tissue are unclear. We examined the biophysical and molecular properties of INa in cells isolated from the canine pulmonary sleeve and compared the properties to left atrial tissue. PV and left atrial myocytes were isolated and patch clamp techniques were used to record INa. Action potential recordings from either tissue type were made using high-resistance electrodes. mRNA was determined using quantitative RT-PCR and proteins were determined by Western blot. Analysis of the action potential characteristics showed that PV tissue had a lower Vmax compared with left atrial tissue. Fast INa showed that current density was slightly lower in PV cells compared with LA cells (-96 ± 18.7 pA/pF vs. -120 ± 6.7 pA/pF, respectively, p < 0.05). The recovery from inactivation of INa in PV cells was slightly slower but no marked difference in steady-state inactivation was noted. Analysis of late INa during a 225-ms pulse showed that late INa was significantly smaller in PV cells compared to LA cells at all measured time points into the pulse. These results suggest PV cells have lower density of both peak and late INa. Molecular analysis of Nav1.5 and the four beta subunits showed lower levels of Nav1.5 as well as Navβ1 subunits, confirming the biophysical findings. These data show that a lower density of INa may lead to depression of excitability and predispose the PV collar to re-entrant circuits under pathophysiological conditions.
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Affiliation(s)
- Hector Barajas-Martinez
- Department of Experimental Cardiology, Masonic Medical Research Laboratory, 2150 Bleecker Street, Utica, NY, 13501, USA
| | - Robert J Goodrow
- Department of Experimental Cardiology, Masonic Medical Research Laboratory, 2150 Bleecker Street, Utica, NY, 13501, USA
| | - Dan Hu
- Department of Experimental Cardiology, Masonic Medical Research Laboratory, 2150 Bleecker Street, Utica, NY, 13501, USA
| | - Payal Patel
- Department of Experimental Cardiology, Masonic Medical Research Laboratory, 2150 Bleecker Street, Utica, NY, 13501, USA
| | - Mayurika Desai
- Department of Experimental Cardiology, Masonic Medical Research Laboratory, 2150 Bleecker Street, Utica, NY, 13501, USA
| | - Brian K Panama
- Department of Experimental Cardiology, Masonic Medical Research Laboratory, 2150 Bleecker Street, Utica, NY, 13501, USA
| | - Jacqueline A Treat
- Department of Experimental Cardiology, Masonic Medical Research Laboratory, 2150 Bleecker Street, Utica, NY, 13501, USA
| | - Gary L Aistrup
- Department of Experimental Cardiology, Masonic Medical Research Laboratory, 2150 Bleecker Street, Utica, NY, 13501, USA
| | - Jonathan M Cordeiro
- Department of Experimental Cardiology, Masonic Medical Research Laboratory, 2150 Bleecker Street, Utica, NY, 13501, USA.
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28
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Nassereddine H, Cazes A, Verdonk C, Assous B, Dautry R, Nataf P, Wassef M, Deschamps L. Atrial angioleiomyoma with myopericytoma-like features: a case report. Cardiovasc Pathol 2017; 28:7-10. [PMID: 28219756 DOI: 10.1016/j.carpath.2017.02.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 01/31/2017] [Accepted: 02/03/2017] [Indexed: 11/22/2022] Open
Abstract
A 66-year-old female patient was referred to our hospital for resection of a right atrial mass. Four months earlier, she had suffered an acute cerebrovascular accident due to occlusion of the sylvian segment of the right middle cerebral artery from atheromatous tight stenosis in the right internal carotid artery. Later, investigations with transthoracic and transesophageal echocardiography revealed a 3.4-cm right atrial mass that was resected surgically. Microscopic evaluation revealed a well-circumscribed nodular tumor, located within the interatrial septum, and corresponding to an angioleiomyoma (ALM). This tumor differs histologically from atrial myxoma. ALM is a ubiquitous benign tumor but has never been reported to occur in the atrium. ALM can mimic cardiac myxoma and should be considered in the differential diagnosis of atrial tumors.
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29
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Larsen J, Bushnell P, Steffensen J, Pedersen M, Qvortrup K, Brill R. Characterization of the functional and anatomical differences in the atrial and ventricular myocardium from three species of elasmobranch fishes: smooth dogfish (Mustelus canis), sandbar shark (Carcharhinus plumbeus), and clearnose skate (Raja eglanteria). J Comp Physiol B 2016; 187:291-313. [PMID: 27686667 DOI: 10.1007/s00360-016-1034-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 08/25/2016] [Accepted: 09/13/2016] [Indexed: 01/15/2023]
Abstract
We assessed the functional properties in atrial and ventricular myocardium (using isolated cardiac strips) of smooth dogfish (Mustelus canis), clearnose skate (Raja eglanteria), and sandbar shark (Carcharhinus plumbeus) by blocking Ca2+ release from the sarcoplasmic reticulum (SR) with ryanodine and thapsigargin and measuring the resultant changes in contraction-relaxation parameters and the force-frequency relationship at 20 °C and 30 °C. We also examined ultrastructural differences with electron microscopy. In tissues from smooth dogfish, net force (per cross-sectional area) and measures of the speeds of contraction and relaxation were all higher in atrial than ventricular myocardium at both temperatures. Atrial-ventricular differences were evident in the other two species primarily in measures of the rates of contraction and relaxation. Ryanodine-thapsigargin treatment reduced net force and its maximum positive first derivative (i.e., contractility), and increased time to 50 % relaxation in atrial tissue from smooth dogfish at 30 °C. It also increased times to peak force and half relaxation in clearnose skate atrial and ventricular tissue at both temperatures, but only in atrial tissue from sandbar shark at 30 °C; indicating that SR involvement in excitation-contraction (EC) coupling is species- and temperature-specific in elasmobranch fishes, as it is in teleost fishes. Atrial and ventricular myocardium from all three species displayed a negative force-frequency relationship, but there was no evidence that SR involvement in EC coupling was influenced by heart rate. SR was evident in electron micrographs, generally located in proximity to mitochondria and intercalated discs, and to a lesser extent between the myofibrils; with mitochondria being more numerous in ventricular than atrial myocardium in all three species.
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Affiliation(s)
- Julie Larsen
- Marine Biological Section, University of Copenhagen, Strandpromenaden 5, 3000, Helsingør, Denmark
| | - Peter Bushnell
- Department of Biology, Indiana University South Bend, 1700 Mishawaka Avenue, South Bend, IN, 46634-7111, USA
| | - John Steffensen
- Marine Biological Section, University of Copenhagen, Strandpromenaden 5, 3000, Helsingør, Denmark
| | - Morten Pedersen
- Department of Science and Environment, Roskilde University, Universitetsvej 1, 4000, Roskilde, Denmark
| | - Klaus Qvortrup
- Department of Biomedical Sciences/CFIM, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Richard Brill
- Behavioral Ecology Branch, Ecosystems Processes Division, Northeast Fisheries Science Center, National Marine Fisheries Service, NOAA, Sandy Hook, NJ, USA. .,Virginia Institute of Marine Science, PO Box 1346, Gloucester Point, VA, 23062, USA.
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30
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Odnoshivkina YG, Sytchev VI, Petrov AM. Cholesterol regulates contractility and inotropic response to β2-adrenoceptor agonist in the mouse atria: Involvement of G i-protein-Akt-NO-pathway. J Mol Cell Cardiol 2016; 107:27-40. [PMID: 27170493 DOI: 10.1016/j.yjmcc.2016.05.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 05/03/2016] [Accepted: 05/04/2016] [Indexed: 10/21/2022]
Abstract
Majority of cardiac β2-adrenoceptors is located in cholesterol-rich microdomains. Here, we have investigated the underlying mechanisms by which a slight to moderate cholesterol depletion with methyl-β-cyclodextrin (MβCD, 1 and 5mM) interferes with contractility and inotropic effect of β2-adrenergic agonist (fenoterol, 50μM) in the mouse atria. Treatment with MβCD itself increased amplitude of Ca2+ transient but did not change the contraction amplitude due to a clamping action of elevated NO. Cholesterol depletion significantly attenuated the positive inotropic response to fenoterol which is accompanied by increase in NO generation and decrease in Ca2+ transient. Influence of 1mM MβCD on the fenoterol-driven changes in both contractility and NO level was strongly attenuated by inhibition of Gi-protein (pertussis toxin), Akt (Akt 1/2 kinase inhibitor) or NO-synthase (L-NAME). After exposure to 5mM MβCD, pertussis toxin or Akt inhibitor could recover the β2-agonist effects on contractility, NO production and Ca2+ transient, while L-NAME only reduced NO level. An adenylyl cyclase activator (forskolin, 50nM) had no influence on the MβCD-induced changes in the β2-agonist effects. Obtained results suggest that slight cholesterol depletion upregulates Gi-protein/Akt/NO-synthase signaling that attenuates the positive inotropic response to β2-adrenergic stimulation without altering the Ca2+ transient. Whilst moderate cholesterol depletion additionally could suppress the enhancement of the Ca2+ transient amplitude caused by the β2-adrenergic agonist administration in Gi-protein/Akt-dependent but NO-independent manner.
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Affiliation(s)
- Yulia G Odnoshivkina
- Department of Normal Physiology, Kazan State Medical University, Kazan 420012, Russia
| | - Vaycheslav I Sytchev
- Department of Normal Physiology, Kazan State Medical University, Kazan 420012, Russia
| | - Alexey M Petrov
- Department of Normal Physiology, Kazan State Medical University, Kazan 420012, Russia.
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31
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García-Villarreal OA. [Cox-maze III procedure for atrial fibrillation. A preliminary study]. Arch Cardiol Mex 2016; 86:208-13. [PMID: 27130883 DOI: 10.1016/j.acmx.2016.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 02/23/2016] [Accepted: 02/23/2016] [Indexed: 10/21/2022] Open
Abstract
AIM To compare the efectiveness of the cut-and-sew Cox-maze III procedure against the Cox-maze IV peocedure by means of intraoperative bipolar radiofrequency delivery clamp. MATERIAL From January 2011 to October 2014, 50 patients were operated on with surgery for atrial fibrillation. All cases underwent mitral valve surgery as the first procedure, and secondarily a surgical procedure for atrial fibrillation was also performed. There were 2 groups. Group I (Cox-maze III «cut-and-sew»), and Group II (Cox-maze IV, intraoperative bipolar radiofrequency ablation). Group I was formed by 36 patients, and Group II by 14. All cases had atrial fibrillation longer than 1 year. The end-point was freedom of atrial fibrillation. RESULTS There was no statistically significant difference between both groups regarding the basal and operative characteristics. Operative mortality was of 2 cases in the Group I, and no cases for Group II (P=0.9). A high tendency to eliminate atrial fibrillation in favour of Group I was observed (92% vs 53%, P<.001) in a 6 months follow-up. CONCLUSIONS Classic standard Cox-maze III procedure showed superiority to eliminate atrial fibrillation over the Cox-maze IV procedure made with bipolar radiofrequency ablation clamp in patients with concomitant mitral valve disease.
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Hu D, Barajas-Martínez H, Burashnikov A, Panama BK, Cordeiro JM, Antzelevitch C. Mechanisms underlying atrial-selective block of sodium channels by Wenxin Keli: Experimental and theoretical analysis. Int J Cardiol 2016; 207:326-34. [PMID: 26820362 DOI: 10.1016/j.ijcard.2016.01.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 12/29/2015] [Accepted: 01/01/2016] [Indexed: 12/19/2022]
Abstract
INTRODUCTION Atrial-selective inhibition of cardiac sodium channel current (INa) and INa-dependent parameters has been shown to contribute to the safe and effective management of atrial fibrillation. The present study was designed to examine the basis for the atrial-selective actions of Wenxin Keli. METHODS Whole cell INa was recorded at room temperature in canine atrial and ventricular myocytes. Trains of 40 pulses were elicited over a range of pulse durations and interpulse intervals to determine tonic and use-dependent block. A Markovian model for INa that incorporates interaction of Wenxin Keli with different states of the channel was developed to examine the basis for atrial selectivity of the drug. RESULTS Our data indicate that Wenxin Keli does not bind significantly to either closed or open states of the sodium channel, but binds very rapidly to the inactivated state of the channel and dissociates rapidly from the closed state. Action potentials recorded from atrial and ventricular preparations in the presence of 5g/L Wenxin Keli were introduced into the computer model in current clamp mode to simulate the effects on maximum upstroke velocity (Vmax). The model predicted much greater inhibition of Vmax in atrial vs. ventricular cells at rapid stimulation rates. CONCLUSION Our findings suggest that atrial selectivity of Wenxin Keli to block INa is due to more negative steady-state inactivation, less negative resting membrane potential, and shorter diastolic intervals in atrial vs. ventricular cells at rapid activation rates. These actions of Wenxin Keli account for its relatively safe and effective suppression of atrial fibrillation.
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Affiliation(s)
- Dan Hu
- Masonic Medical Research Laboratory, Utica, NY, United States
| | | | | | - Brian K Panama
- Masonic Medical Research Laboratory, Utica, NY, United States
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33
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Begieneman MPV, Emmens RW, Rijvers L, Kubat B, Paulus WJ, Vonk ABA, Rozendaal L, Biesbroek PS, Wouters D, Zeerleder S, van Ham M, Heymans S, van Rossum AC, Niessen HWM, Krijnen PAJ. Ventricular myocarditis coincides with atrial myocarditis in patients. Cardiovasc Pathol 2015; 25:141-8. [PMID: 26764148 DOI: 10.1016/j.carpath.2015.12.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 10/06/2015] [Accepted: 12/01/2015] [Indexed: 11/29/2022] Open
Abstract
INTRODUCTION Atrial fibrillation (AF) is a common complication in myocarditis. Atrial inflammation has been suggested to play an important role in the pathophysiology of AF. However, little is known about the occurrence of atrial inflammation in myocarditis patients. Here, we analyzed inflammatory cell numbers in the atria of myocarditis patients without symptomatic AF. METHODS Cardiac tissue was obtained postmortem from lymphocytic myocarditis patients (n=6), catecholamine-induced myocarditis patients (n=5), and control patients without pathological evidence of heart disease (n=5). Tissue sections of left and right ventricle and left and right atrium were stained for myeloperoxidase (neutrophilic granulocytes), CD45 (lymphocytes), and CD68 (macrophages). These cells were subsequently quantified in atrial and ventricular myocardium and atrial adipose tissue. RESULTS In lymphocytic myocarditis patients, a significant increase was observed for lymphocytes in the left atrial adipose tissue. In catecholamine-induced myocarditis patients, significant increases were found in the atria for all three inflammatory cell types. Infiltrating inflammatory cell numbers in the atrial myocardium correlated positively with those in the ventricles, especially in catecholamine-induced myocarditis patients. CONCLUSIONS To a varying extent, atrial myocarditis occurs concurrently with ventricular myocarditis in patients diagnosed with myocarditis of different etiology. This provides a substrate that potentially predisposes myocarditis patients to the development of AF and subsequent complications such as sudden cardiac death and heart failure.
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Affiliation(s)
- Mark P V Begieneman
- Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands; ICaR-VU, VU University Medical Center, Amsterdam, the Netherlands; Dutch Forensic Institute, The Hague, the Netherlands
| | - Reindert W Emmens
- Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands; ICaR-VU, VU University Medical Center, Amsterdam, the Netherlands; Department of Immunopathology, Sanquin Research, Amsterdam, the Netherlands.
| | - Liza Rijvers
- Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands
| | - Bela Kubat
- Dutch Forensic Institute, The Hague, the Netherlands
| | - Walter J Paulus
- ICaR-VU, VU University Medical Center, Amsterdam, the Netherlands; Department of Physiology, VU University Medical Center, Amsterdam, the Netherlands
| | - Alexander B A Vonk
- Department of Cardiac Surgery, VU University Medical Center, Amsterdam, the Netherlands
| | - Lawrence Rozendaal
- Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands; ICaR-VU, VU University Medical Center, Amsterdam, the Netherlands
| | - P Stefan Biesbroek
- Department of Cardiology, VU University Medical Center, Amsterdam, the Netherlands
| | - Diana Wouters
- Department of Immunopathology, Sanquin Research, Amsterdam, the Netherlands
| | - Sacha Zeerleder
- Department of Immunopathology, Sanquin Research, Amsterdam, the Netherlands; Department of Hematology, Academic Medical Center, Amsterdam, the Netherlands
| | - Marieke van Ham
- Department of Immunopathology, Sanquin Research, Amsterdam, the Netherlands
| | - Stephane Heymans
- Department of Cardiology, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Albert C van Rossum
- ICaR-VU, VU University Medical Center, Amsterdam, the Netherlands; Department of Cardiology, VU University Medical Center, Amsterdam, the Netherlands
| | - Hans W M Niessen
- Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands; ICaR-VU, VU University Medical Center, Amsterdam, the Netherlands; Department of Cardiac Surgery, VU University Medical Center, Amsterdam, the Netherlands
| | - Paul A J Krijnen
- Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands; ICaR-VU, VU University Medical Center, Amsterdam, the Netherlands
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Brandenburg S, Arakel EC, Schwappach B, Lehnart SE. The molecular and functional identities of atrial cardiomyocytes in health and disease. Biochim Biophys Acta 2015; 1863:1882-93. [PMID: 26620800 DOI: 10.1016/j.bbamcr.2015.11.025] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 11/17/2015] [Accepted: 11/23/2015] [Indexed: 12/28/2022]
Abstract
Atrial cardiomyocytes are essential for fluid homeostasis, ventricular filling, and survival, yet their cell biology and physiology are incompletely understood. It has become clear that the cell fate of atrial cardiomyocytes depends significantly on transcription programs that might control thousands of differentially expressed genes. Atrial muscle membranes propagate action potentials and activate myofilament force generation, producing overall faster contractions than ventricular muscles. While atria-specific excitation and contractility depend critically on intracellular Ca(2+) signalling, voltage-dependent L-type Ca(2+) channels and ryanodine receptor Ca(2+) release channels are each expressed at high levels similar to ventricles. However, intracellular Ca(2+) transients in atrial cardiomyocytes are markedly heterogeneous and fundamentally different from ventricular cardiomyocytes. In addition, differential atria-specific K(+) channel expression and trafficking confer unique electrophysiological and metabolic properties. Because diseased atria have the propensity to perpetuate fast arrhythmias, we discuss our understanding about the cell-specific mechanisms that lead to metabolic and/or mitochondrial dysfunction in atrial fibrillation. Interestingly, recent work identified potential atria-specific mechanisms that lead to early contractile dysfunction and metabolic remodelling, suggesting highly interdependent metabolic, electrical, and contractile pathomechanisms. Hence, the objective of this review is to provide an integrated model of atrial cardiomyocytes, from tissue-specific cell properties, intracellular metabolism, and excitation-contraction (EC) coupling to early pathological changes, in particular metabolic dysfunction and tissue remodelling due to atrial fibrillation and aging. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.
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Affiliation(s)
- Sören Brandenburg
- Heart Research Center Göttingen, University Medical Center Göttingen, 37075 Göttingen, Germany; Department of Cardiology & Pulmonology, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Eric C Arakel
- Heart Research Center Göttingen, University Medical Center Göttingen, 37075 Göttingen, Germany; Department of Molecular Biology, University Medical Center Göttingen, 37073 Göttingen, Germany
| | - Blanche Schwappach
- Heart Research Center Göttingen, University Medical Center Göttingen, 37075 Göttingen, Germany; Department of Molecular Biology, University Medical Center Göttingen, 37073 Göttingen, Germany; German Centre for Cardiovascular Research (DZHK) site Göttingen, 37075 Göttingen, Germany
| | - Stephan E Lehnart
- Heart Research Center Göttingen, University Medical Center Göttingen, 37075 Göttingen, Germany; Department of Cardiology & Pulmonology, University Medical Center Göttingen, 37075 Göttingen, Germany; German Centre for Cardiovascular Research (DZHK) site Göttingen, 37075 Göttingen, Germany.
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Odnoshivkina UG, Sytchev VI, Nurullin LF, Giniatullin AR, Zefirov AL, Petrov AM. β2-adrenoceptor agonist-evoked reactive oxygen species generation in mouse atria: implication in delayed inotropic effect. Eur J Pharmacol 2015; 765:140-53. [PMID: 26297975 DOI: 10.1016/j.ejphar.2015.08.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 08/05/2015] [Accepted: 08/17/2015] [Indexed: 12/20/2022]
Abstract
Fenoterol, a β2-adrenoceptor agonist, has anti-apoptotic action in cardiomyocytes and induces a specific pattern of downstream signaling. We have previously reported that exposure to fenoterol (5 μM) results in a delayed positive inotropic effect which is related to changes in both Ca2+ transient and NO. Here, the changes in reactive oxygen species (ROS) production in response to the fenoterol administration and the involvement of ROS in effect of this agonist on contractility were investigated in mouse isolated atria. Stimulation of β2-adrenoceptor increases a level of extracellular ROS, while intracellular ROS level rises only after removal of fenoterol from the bath. NADPH-oxidase inhibitor (apocynin) prevents the increase in ROS production and the Nox2 isoform is immunofluorescently colocalized with β2-adrenoceptor at the atrial myocytes. Treatments with antioxidants (N-acetyl-L-cysteine, NADPH inhibitors, exogenous catalases) significantly inhibit the fenoterol induced increase in the contraction amplitude, probably by attenuating Ca2+ transient and up-regulating NO production. ROS generated in a β2-adrenoceptor-dependent manner can potentiate the activity of some Ca2+ channels. Indeed, inhibition of ryanodine receptors, TRPV-or L-type Ca2+- channels shows a similar efficacy in reduction of positive inotropic effect of both fenoterol and H2O2. In addition, detection of mitochondrial ROS indicates that fenoterol triggers a slow increase in ROS which is prevented by rotenone, but rotenone has no impact on the inotropic effect of fenoterol. We suggest that stimulation of β2-adrenoceptor with fenoterol causes the activation of NADPH-oxidase and after the agonist removal extracellularly generated ROS penetrates into the cell, increasing the atrial contractions probably via Ca2+ channels.
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Affiliation(s)
- Ulia G Odnoshivkina
- Department of Normal Physiology, Kazan State Medical University, Butlerova st., 49, Kazan 420012, Russia
| | - Vaycheslav I Sytchev
- Department of Normal Physiology, Kazan State Medical University, Butlerova st., 49, Kazan 420012, Russia
| | - Leniz F Nurullin
- Kazan Institute of Biochemistry and Biophysics, Kazan Scientific Center of Russian Academy of Sciences, Laboratory of Biophysics of Synaptic Processes, Lobatchevsky str. 2/31, P.O. 30, Kazan 420111, Russia
| | - Arthur R Giniatullin
- Department of Normal Physiology, Kazan State Medical University, Butlerova st., 49, Kazan 420012, Russia
| | - Andrei L Zefirov
- Department of Normal Physiology, Kazan State Medical University, Butlerova st., 49, Kazan 420012, Russia
| | - Alexey M Petrov
- Department of Normal Physiology, Kazan State Medical University, Butlerova st., 49, Kazan 420012, Russia.
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Jones SA, Lancaster MK. Progressive age-associated activation of JNK associates with conduction disruption in the aged atrium. Mech Ageing Dev 2015; 146-148:72-80. [PMID: 25956603 PMCID: PMC4461009 DOI: 10.1016/j.mad.2015.05.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 04/29/2015] [Accepted: 05/01/2015] [Indexed: 12/19/2022]
Abstract
Guinea pig atria from multiple ages ranging from neonate to old age were compared. Action potential conduction velocity showed a significant reduction in advanced age. Connexin43 protein reduced dramatically in the right atria with increasing age. An age-dependent rise in activated-JNK correlated with a rise in phosphorylated Cx43. JNK signalling is a mediator of gap junctional remodelling with increased age.
Connexin43 (Cx43) is critical for maintaining electrical conduction across atrial muscle. During progressive ageing atrial conduction slows associating with increasing susceptibility to arrhythmias. Changes in Cx43 protein expression, or its phosphorylation status, can instigate changes in the conduction of the cardiac action potential. This study investigated whether increased levels of activated c-jun N-terminal kinase (JNK) is responsible for the decline of Cx43 during ageing. Right atria from guinea pigs aged between 1 day and 38 months of age were examined. The area of the intercalated disc increased with age concurrent with a 75% decline in C43 protein expression. An age-dependent increase in activated-JNK correlated with a rise in phosphorylated Cx43, but also slowing of action potential conduction velocity across the atria from 0.38 ± 0.01 m/s at 1 month of age to 0.30 ± 0.01 m/s at 38 months. The JNK activator anisomycin increased activated JNK in myocytes and reduced Cx43 protein expression simulating ageing. The JNK inhibitor SP600125, was found to eradicate almost all trace of Cx43 protein. We conclude that in vivo activation of JNK increases with age leading to the loss of Cx43 protein resulting in impaired conduction and contributing to the increasing risk of atrial arrhythmias with advancing age.
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Affiliation(s)
- Sandra A Jones
- School of Biological, Biomedical and Environmental Sciences, University of Hull, Kingston-upon-Hull, HU6 7RX, UK.
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Cordeiro JM, Zeina T, Goodrow R, Kaplan AD, Thomas LM, Nesterenko VV, Treat JA, Hawel L, Byus C, Bett GC, Rasmusson RL, Panama BK. Regional variation of the inwardly rectifying potassium current in the canine heart and the contributions to differences in action potential repolarization. J Mol Cell Cardiol 2015; 84:52-60. [PMID: 25889894 DOI: 10.1016/j.yjmcc.2015.04.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 03/09/2015] [Accepted: 04/08/2015] [Indexed: 10/23/2022]
Abstract
The inward rectifier potassium current, IK1, contributes to the terminal phase of repolarization of the action potential (AP), as well as the value and stability of the resting membrane potential. Regional variation in IK1 has been noted in the canine heart, but the biophysical properties have not been directly compared. We examined the properties and functional contribution of IK1 in isolated myocytes from ventricular, atrial and Purkinje tissue. APs were recorded from canine left ventricular midmyocardium, left atrial and Purkinje tissue. The terminal rate of repolarization of the AP in ventricle, but not in Purkinje, depended on changes in external K(+) ([K(+)]o). Isolated ventricular myocytes had the greatest density of IK1 while atrial myocytes had the lowest. Furthermore, the outward component of IK1 in ventricular cells exhibited a prominent outward component and steep negative slope conductance, which was also enhanced in 10 mM [K(+)]o. In contrast, both Purkinje and atrial cells exhibited little outward IK1, even in the presence of 10 mM [K(+)]o, and both cell types showed more persistent current at positive potentials. Expression of Kir2.1 in the ventricle was 76.9-fold higher than that of atria and 5.8-fold higher than that of Purkinje, whereas the expression of Kir2.2 and Kir2.3 subunits was more evenly distributed in Purkinje and atria. Finally, AP clamp data showed distinct contributions of IK1 for each cell type. IK1 and Kir2 subunit expression varies dramatically in regions of the canine heart and these regional differences in Kir2 expression likely underlie regional distinctions in IK1 characteristics, contributing to variations in repolarization in response to in [K(+)]o changes.
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Affiliation(s)
- Jonathan M Cordeiro
- Department of Experimental Cardiology, Masonic Medical Research Laboratory, Utica, NY, United States
| | - Tanya Zeina
- Department of Experimental Cardiology, Masonic Medical Research Laboratory, Utica, NY, United States
| | - Robert Goodrow
- Department of Experimental Cardiology, Masonic Medical Research Laboratory, Utica, NY, United States
| | - Aaron D Kaplan
- Department of Physiology and Biophysics, State University of New York, University of Buffalo, Buffalo, NY, United States
| | - Lini M Thomas
- Department of Experimental Cardiology, Masonic Medical Research Laboratory, Utica, NY, United States
| | - Vladislav V Nesterenko
- Department of Experimental Cardiology, Masonic Medical Research Laboratory, Utica, NY, United States
| | - Jacqueline A Treat
- Department of Experimental Cardiology, Masonic Medical Research Laboratory, Utica, NY, United States
| | - Leo Hawel
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA, United States
| | - Craig Byus
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA, United States
| | - Glenna C Bett
- Department of Physiology and Biophysics, State University of New York, University of Buffalo, Buffalo, NY, United States; Department of Obstetrics and Gynecology, State University of New York, University of Buffalo, Buffalo, NY, United States
| | - Randall L Rasmusson
- Department of Physiology and Biophysics, State University of New York, University of Buffalo, Buffalo, NY, United States
| | - Brian K Panama
- Department of Experimental Cardiology, Masonic Medical Research Laboratory, Utica, NY, United States.
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Clarke JD, Caldwell JL, Horn MA, Bode EF, Richards MA, Hall MCS, Graham HK, Briston SJ, Greensmith DJ, Eisner DA, Dibb KM, Trafford AW. Perturbed atrial calcium handling in an ovine model of heart failure: potential roles for reductions in the L-type calcium current. J Mol Cell Cardiol 2015; 79:169-79. [PMID: 25463272 PMCID: PMC4312356 DOI: 10.1016/j.yjmcc.2014.11.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 11/10/2014] [Accepted: 11/11/2014] [Indexed: 12/19/2022]
Abstract
Heart failure (HF) is commonly associated with reduced cardiac output and an increased risk of atrial arrhythmias particularly during β-adrenergic stimulation. The aim of the present study was to determine how HF alters systolic Ca(2+) and the response to β-adrenergic (β-AR) stimulation in atrial myocytes. HF was induced in sheep by ventricular tachypacing and changes in intracellular Ca(2+) concentration studied in single left atrial myocytes under voltage and current clamp conditions. The following were all reduced in HF atrial myocytes; Ca(2+) transient amplitude (by 46% in current clamped and 28% in voltage clamped cells), SR dependent rate of Ca(2+) removal (kSR, by 32%), L-type Ca(2+) current density (by 36%) and action potential duration (APD90 by 22%). However, in HF SR Ca(2+) content was increased (by 19%) when measured under voltage-clamp stimulation. Inhibiting the L-type Ca(2+) current (ICa-L) in control cells reproduced both the decrease in Ca(2+) transient amplitude and increase of SR Ca(2+) content observed in voltage-clamped HF cells. During β-AR stimulation Ca(2+) transient amplitude was the same in control and HF cells. However, ICa-L remained less in HF than control cells whilst SR Ca(2+) content was highest in HF cells during β-AR stimulation. The decrease in ICa-L that occurs in HF atrial myocytes appears to underpin the decreased Ca(2+) transient amplitude and increased SR Ca(2+) content observed in voltage-clamped cells.
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Affiliation(s)
- Jessica D Clarke
- Institute of Cardiovascular Science, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton St, Manchester M13 9PT, UK
| | - Jessica L Caldwell
- Institute of Cardiovascular Science, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton St, Manchester M13 9PT, UK
| | - Margaux A Horn
- Institute of Cardiovascular Science, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton St, Manchester M13 9PT, UK
| | - Elizabeth F Bode
- Institute of Cardiovascular Science, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton St, Manchester M13 9PT, UK
| | - Mark A Richards
- Institute of Cardiovascular Science, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton St, Manchester M13 9PT, UK
| | - Mark C S Hall
- Liverpool Heart and Chest Hospital, Thomas Drive, Liverpool L14 3PE, UK
| | - Helen K Graham
- Institute of Cardiovascular Science, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton St, Manchester M13 9PT, UK
| | - Sarah J Briston
- Institute of Cardiovascular Science, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton St, Manchester M13 9PT, UK
| | - David J Greensmith
- Institute of Cardiovascular Science, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton St, Manchester M13 9PT, UK
| | - David A Eisner
- Institute of Cardiovascular Science, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton St, Manchester M13 9PT, UK
| | - Katharine M Dibb
- Institute of Cardiovascular Science, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton St, Manchester M13 9PT, UK
| | - Andrew W Trafford
- Institute of Cardiovascular Science, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton St, Manchester M13 9PT, UK.
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Li L, Hatcher JT, Hoover DB, Gu H, Wurster RD, Cheng ZJ. Distribution and morphology of calcitonin gene-related peptide and substance P immunoreactive axons in the whole-mount atria of mice. Auton Neurosci 2014; 181:37-48. [PMID: 24433968 PMCID: PMC10506417 DOI: 10.1016/j.autneu.2013.12.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 11/17/2013] [Accepted: 12/17/2013] [Indexed: 11/30/2022]
Abstract
The murine model has been used to investigate the role of cardiac sensory axons in various disease states. However, the distribution and morphological structures of cardiac nociceptive axons in normal murine tissues have not yet been well characterized. In this study, whole-mount atria from FVB mice were processed with calcitonin gene-related peptide (CGRP) and substance P (SP) primary antibodies followed by secondary antibodies, and then examined using confocal microscopy. We found: 1) Large CGRP-IR axon bundles entered the atria with the major veins, and these large bundles bifurcated into small bundles and single axons that formed terminal end-nets and free endings in the epicardium. Varicose CGRP-IR axons had close contacts with muscle fibers, and some CGRP-IR axons formed varicosities around principle neurons (PNs) within intrinsic cardiac ganglia (ICGs). 2) SP-IR axons also were found in the same regions of the atria, attached to veins, and within cardiac ganglia. Similar to CGRP-IR axons, these SP-IR axons formed terminal end-nets and free endings in the atrial epicardium and myocardium. Within ICGs, SP-IR axons formed varicose endings around PNs. However, SP-IR nerve fibers were less abundant than CGRP-IR fibers in the atria. 3) None of the PNs were CGRP-IR or SP-IR. 4) CGRP-IR and SP-IR often colocalized in terminal varicosities around PNs. Collectively, our data document the distribution pattern and morphology of CGRP-IR and SP-IR axons and terminals in different regions of the atria. This knowledge provides useful information for CGRP-IR and SP-IR axons that can be referred to in future studies of pathological remodeling.
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Affiliation(s)
- Liang Li
- Biomolecular Science Center, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816, United States
| | - Jeffrey T Hatcher
- Biomolecular Science Center, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816, United States
| | - Donald B Hoover
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, United States
| | - He Gu
- Department of Anesthesia, University of Iowa Hospital and Clinics, Iowa City, IA 52242, United States
| | - Robert D Wurster
- Department of Physiology, Loyola University, Stritch School of Medicine, Maywood, IL 60153, United States
| | - Zixi Jack Cheng
- Biomolecular Science Center, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816, United States.
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Dhull VS, Sharma P, Singla S, Faizi NA, Thulkar S, Bal C, Kumar R. Extensive Extranodal Involvement of Rare Sites in Non Hodgkin's Lymphoma Detected on (18)F- FDG PET-CT: A Case Report. Nucl Med Mol Imaging 2012; 47:125-9. [PMID: 24900093 DOI: 10.1007/s13139-012-0183-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 10/16/2012] [Accepted: 10/23/2012] [Indexed: 11/30/2022] Open
Abstract
We present a case of a 23 year-old male treated for Hodgkin's lymphoma who developed diffuse large B-cell lymphoma (DLBCL) 8 years after achieving remission. (18)F-fluorodeoxyglucose positron emission tomography computed tomography ((18)F-FDG PET-CT) was done, which revealed extensive extranodal involvement of bilateral atria, bilateral kidneys, ileo-caecal junction and left testis along with mesenteric and retroperitoneal lymph nodal involvement. Renal and cardiac lesions were not detected by contrast-enhanced CT. Simultaneous lymphomatous involvement of rare sites such as heart, kidneys and testis in a single patient has not been reported before.
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Affiliation(s)
- Varun Singh Dhull
- Department of Nuclear Medicine, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029 India
| | - Punit Sharma
- Department of Nuclear Medicine, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029 India
| | - Suhas Singla
- Department of Nuclear Medicine, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029 India
| | - Nauroze Asghar Faizi
- Department of Nuclear Medicine, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029 India ; Department of Radiodiagnosis, All India Institute of Medical Sciences, New Delhi, India
| | - Sanjay Thulkar
- Department of Radiodiagnosis, All India Institute of Medical Sciences, New Delhi, India
| | - Chandersekhar Bal
- Department of Nuclear Medicine, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029 India
| | - Rakesh Kumar
- Department of Nuclear Medicine, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029 India
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Kuncová J, Slavíková J. Vasoactive intestinal polypeptide concentrations in heart atria of hypothyroid rats. Exp Clin Cardiol 2001; 6:137-141. [PMID: 20428449 PMCID: PMC2858988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
OBJECTIVES To determine putative effects of various protocols of propylthiouracil (PTU)-induced hypothyroidism on vasoactive intestinal polypeptide-like immunoreactivity (VIP-LI) levels in the atria of developing and adult female rats. ANIMALS AND METHODS Perinatal hypothyroidism was induced by treating pregnant rats with 0.05% PTU in drinking water from late gestation till the age of 60 days (P-PTU). Adult rats were given PTU for 10, 30 or 70 days (PTU-10, PTU-30 and PTU-70, respectively). Corresponding age-matched controls were left intact (P-Cont, Cont-10, Cont-30 and Cont-70, respectively). Resting heart rate, serum total thyroxine concentration, body weight and atrial weight were determined in all animals. VIP-LI levels in tissue extracts were measured by radioimmunoassay. RESULTS The values of heart rate, serum total thyroxine, body weight and atrial weight showed that 10-day treatment did not suppress thyroid gland function completely. However, the remaining experimental protocols were sufficient to reach stable hypothyroid conditions. Thyroid hormone deficiency led to a significant increase in VIP-LI levels in both atria of PTU-30 and PTU-70 rats (P<0.01 versus corresponding controls). Interestingly, in P-PTU atria, VIP-LI reached significantly higher values than in rats treated with PTU for the same time during adulthood (PTU-70). CONCLUSIONS These results provide new evidence that hypothyroidism interferes with VIP-ergic innervation in rat heart atria. The impact of thyroid hormone deficiency on VIP-LI levels differed in P-PTU and PTU-70 rats suggesting that thyroid hormone may play an important part in the development of VIP-ergic innervation in rat heart atria.
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Affiliation(s)
- Jitka Kuncová
- Correspondence and reprints: Dr Jitka Kuncová, Faculty of Medicine, Charles University, Lidická 1, 301 66 Plzeň, Czech Republic. Telephone 420 19 7597 248, fax 420 19 521 943, e-mail
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