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Sample records for human atrial appendage

  1. Differential gene expression during atrial structural remodeling in human left and right atrial appendages in atrial fibrillation

    Institute of Scientific and Technical Information of China (English)

    Hui Zhu; Wei Zhang; Ming Zhong; Gong Zhang; Yun Zhang

    2011-01-01

    Extracellular matrix (ECM) remodeling increases the vulnerability to atrial fibrillation (AF). Some gene expressions are crucial for the metabolism of ECM. The left atrium plays an important role in maintaining AF.However, most studies investigated only the right atrial tissue. We therefore chose human tissue samples from both the left and right atrial to detect the different gene expressions during structural remodeling in AF. The atrial appendages tissue samples from 24 patients with chronic AF and 12 patients with sinus rhythm were obtained when they were undergoing mitral/aortic valve replacement operation. The mRNA levels of matrix metalloproteinases-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1), disintegrin, metalloproteases-15, and integrins β1 were determined by reverse transcriptionpolymerase chain reaction (RT-PCR). in AF group, the level of MMP-9 in left atrial appendage (LAA) was increased (P<0.001), while integrin β1 level was decreased (P< 0.05) compared with those expressed in right atrial appendage (RAA) tissue. The levels of disintegrin, metalloproteinases-15, and TIMP-1 genes in the LAA and RAA had no significant differences. The results demonstrated that the gene expressions in the LAA and RAA are different during AF, which implied that the mechanism of atrial structural remodeling in AF is due to multiple sources and is complicated.

  2. Left atrial appendage occlusion

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    Ahmad Mirdamadi

    2013-01-01

    Full Text Available Left atrial appendage (LAA occlusion is a treatment strategy to prevent blood clot formation in atrial appendage. Although, LAA occlusion usually was done by catheter-based techniques, especially percutaneous trans-luminal mitral commissurotomy (PTMC, it can be done during closed and open mitral valve commissurotomy (CMVC, OMVC and mitral valve replacement (MVR too. Nowadays, PTMC is performed as an optimal management of severe mitral stenosis (MS and many patients currently are treated by PTMC instead of previous surgical methods. One of the most important contraindications of PTMC is presence of clot in LAA. So, each patient who suffers of severe MS is evaluated by Trans-Esophageal Echocardiogram to rule out thrombus in LAA before PTMC. At open heart surgery, replacement of the mitral valve was performed for 49-year-old woman. Also, left atrial appendage occlusion was done during surgery. Immediately after surgery, echocardiography demonstrates an echo imitated the presence of a thrombus in left atrial appendage area, although there was not any evidence of thrombus in pre-pump TEE. We can conclude from this case report that when we suspect of thrombus of left atrial, we should obtain exact history of previous surgery of mitral valve to avoid misdiagnosis clotted LAA, instead of obliterated LAA. Consequently, it can prevent additional evaluations and treatments such as oral anticoagulation and exclusion or postponing surgeries including PTMC.

  3. Aneurysm of the Right Atrial Appendage

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    Silvio Henrique Barberato

    2002-02-01

    Full Text Available Atrial aneurysms involving the free wall or atrial appendage are rare entities in cardiology practice and may be associated with atrial arrhythmias or embolic phenomena. We review the literature and report a case of aneurysm of the right atrial appendage in a young adult, whose diagnosis was established with echocardiography after an episode of paroxysmal atrial flutter.

  4. Atrial Fibrillation associated chromosome 4q25 variants are not associated with PITX2c expression in human adult left atrial appendages.

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    Shamone R Gore-Panter

    Full Text Available Atrial Fibrillation (AF, the most common sustained arrhythmia, has a strong genetic component, but the mechanism by which common genetic variants lead to increased AF susceptibility is unknown. Genome-wide association studies (GWAS have identified that the single nucleotide polymorphisms (SNPs most strongly associated with AF are located on chromosome 4q25 in an intergenic region distal to the PITX2 gene. Our objective was to determine whether the AF-associated SNPs on chromosome 4q25 were associated with PITX2c expression in adult human left atrial appendages. Analysis of a lone AF GWAS identified four independent AF risk SNPs at chromosome 4q25. Human adult left atrial appendage tissue was obtained from 239 subjects of European Ancestry and used for SNP analysis of genomic DNA and determination of PITX2c RNA expression levels by quantitative PCR. Subjects were divided into three groups based on their history of AF and pre-operative rhythm. AF rhythm subjects had higher PITX2c expression than those with history of AF but in sinus rhythm. PITX2c expression was not associated with the AF risk SNPs in human adult left atrial appendages in all subjects combined or in each of the three subgroups. However, we identified seven SNPs modestly associated with PITX2c expression located in the introns of the ENPEP gene, ∼54 kb proximal to PITX2. PITX2c expression in human adult left atrial appendages is not associated with the chromosome 4q25 AF risk SNPs; thus, the mechanism by which these SNPs are associated with AF remains enigmatic.

  5. Congenital left atrial appendage aneurysm: Atypical presentation

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    Mehdi Bamous

    2017-01-01

    Full Text Available Congenital left atrial appendage aneurysm is a rare condition caused by dysplasia of the atrial muscles. We report a case of a 14-year-old boy, with a 5-month history of cough and in sinus rhythm. Transthoracic echocardiography and computerized tomographic angiography confirmed the aneurysm of the left atrial appendage which was resected through median sternotomy on cardiopulmonary bypass. This case is presented not only for its rarity but also for its atypical clinical presentation.

  6. Occlusion of left atrial appendage in patients with atrial fibrillation

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    О. Н. Ганеева

    2015-10-01

    Full Text Available The article reviews a new method of prophylaxis of thromboembolitic complications, specifically occlusion of left atrial appendage, in patients with atrial fibrillation. Indications and contraindications for the procedure, as well as a step-by-step process of the intervention itself are described. Special emphasis is placed on the up-to-date evidence and the review of clinical trials.

  7. Left atrial appendage occlusion for stroke prevention in atrial fibrillation

    DEFF Research Database (Denmark)

    Tzikas, Apostolos; Shakir, Samera; Gafoor, Sameer;

    2015-01-01

    Aims: To investigate the safety, feasibility, and efficacy of left atrial appendage occlusion (LAAO) with the AMPLATZER Cardiac Plug (ACP) for stroke prevention in patients with atrial fibrillation (AF). Methods and results: Data from consecutive patients treated in 22 centres were collected...

  8. Right juxtaposition of the atrial appendages.

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    Mathew, R; Replogle, R; Thilenius, O G; Arcilla, R A

    1975-04-01

    We present an infant with right-sided juxtaposition of atrial appendages who had open heart surgery for ventricular septal defect and patent ductus arteriosus. Of 12 cases thus far reported, ventricular d-loop was observed in nine, and normal position of great vessels in four. Contrary to previous views, this condition may not be accompanied by severe conotruncal anomalies.

  9. Juxtaposed atrial appendages: A curiosity with some clinical relevance

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    Anil Kumar Singhi

    2016-01-01

    Full Text Available If the atrial appendages lie adjacent to each other on same side of the great arteries, instead of encircling their roots, they are referred as juxtaposed. Right juxtaposition of atrial appendages is less common than left juxtaposition. The images demonstrate the classical radiological, echocardiographic, and surgical images of juxtaposed atrial appendages. Their clinical incidence, associations, and relevance during interventional and surgical procedures are discussed.

  10. Retrieval of embolized left atrial appendage devices.

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    Fahmy, Peter; Eng, Lim; Saw, Jacqueline

    2016-09-28

    Percutaneous left atrial appendage (LAA) closure is gaining interest as an alternative option for prevention of strokes in patients with Atrial Fibrillation (AF), especially for those with contraindications to anticoagulation. Complications from these procedures are well described in the medical literature. LAA closures may lead to pericardial effusion, device-associated thrombus, and device embolization. Understanding the reasons for embolization, strategies to avoid embolization, and the techniques for retrieval of LAA devices (ACP/AMULET and WATCHMAN) should be appreciated by endovascular implanters. We describe two cases of LAA device embolization that were both successfully retrieved percutaneously and other percutaneous techniques to safely retrieve embolized LAA devices. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  11. Left Atrial Appendage Occlusion for Stroke Prevention.

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    Chanda, Arijit; Reilly, John P

    More than 2.3 million adults in the United States have atrial fibrillation (AF), which exposes them to a 5-fold increased risk of stroke. The left atrial appendage (LAA) appears to be the source of thrombus formation in the vast majority of these patients. Anticoagulation significantly reduces the risk of stroke, but often we encounter patients who have absolute or relative contraindication to anticoagulation. Percutaneous LAA exclusion offers an alternative to anticoagulation to decrease the risk of stroke. Three device systems are currently available in the United States. The WATCHMAN® device is the most studied and approved by Food and Drug Administration (FDA) to be used in patients with AF unsuitable for anticoagulation who are at a high risk of stroke. The Amulet® device is currently being used as part of the AMPLATZER® Amulet® LAA Occluder trial, which is a non-inferiority randomized trial comparing the Amulet® to the WATCHMAN® device. The third device in use is the LARIAT®, which is an FDA approved snare and pre-tied stich system. It is used to approximate soft tissue which in this case is the LAA. It is a hybrid system and requires both epicardial and endocardial access. The main obstacle to percutaneous LAA closure is procedural related complications, which can be minimized with optimum operator experience. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Percutaneous left atrial appendage closure: current state of the art.

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    Jazayeri, Mohammad-Ali; Vuddanda, Venkat; Parikh, Valay; Lakkireddy, Dhanunjaya R

    2017-01-01

    The authors reviewed the seminal and more recent literature surrounding the major modalities for percutaneous left atrial appendage closure used in contemporary practice, with particular emphasis on safety and efficacy, technical challenges, and future developments. Along with the continued practice of surgical left atrial appendage closure, which has evolved substantially with the advent of clipping techniques, a number of percutaneous methods have been developed to close the left atrial appendage with endocardial, epicardial, and hybrid approaches. The last 18 months has seen the Food and Drug Administration approval of the WATCHMAN device for stroke prevention in the United States, the initiation of a randomized controlled trial to further examine the LARIAT device, and an increasing body of literature surrounding use of the AMPLATZER Amulet in Europe. Left atrial appendage closure is a promising alternative to systemic anticoagulation for stroke prevention in appropriate atrial fibrillation patients. The wealth of available data for the various modalities sheds light on the strengths and limitations of each, postprocedural complications and their management, and new areas for exploration. With a plethora of new devices on the horizon, it is a very exciting time in the field of 'appendage-ology' as we pursue new avenues to optimize care for atrial fibrillation patients.

  13. Left atrial appendage occlusion with the AMPLATZER Amulet device

    DEFF Research Database (Denmark)

    Tzikas, Apostolos; Gafoor, Sameer; Meerkin, David

    2016-01-01

    anatomies like "chicken wing" left atrial appendage. Finally, for operators who are switching from AMPLATZER Cardiac Plug to Amulet, the main differences between the two devices with respect to implantation technique are presented. CONCLUSIONS: In conclusion, this document reflects a consensus approach...

  14. Percutaneous vascular plug for incomplete surgical left atrial appendage closure.

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    Levisay, Justin P; Sangodkar, Sandeep; Salinger, Michael H; Lampert, Mark; Feldman, Ted

    2014-04-01

    Surgical left atrial appendage (LAA) exclusion has a failure rate as high as 60% due to persistent residual flow in the LAA or large LAA remnants. We describe a novel technique for treatment of incomplete surgical LAA ligation, and define the mechanism that led to persistence of the remnant LAA without any thrombus formation.

  15. Predictors of left atrial appendage stunning after electrical cardioversion of non-valvular atrial fibrillation

    Institute of Scientific and Technical Information of China (English)

    杨沙宁; 黄从新; 胡晓军; 金立军; 李凤翥; 彭水先

    2003-01-01

    Objective To identify predictors of left atrial appendage stunning after the use of electrical cardioversion to restore sinus rhythm in patients with non-valvular atrial fibrillation.Methods A total of 68 consecutive patients (45 men, 23 women, 60.5±8.7 years of age) with non-valvular atrial fibrillation undergoing electrical cardioversion were enlisted in this study. Clinical and echocardiographic variables were analyzed by univariate regression and multivariate logistic regression to investigate the relationship between occurrences of left atrial appendage stunning and these factors. Results Univariate analysis revealed that, in comparing patients without and with left atrial appendage stunning, there were significant differences in the duration of atrial fibrillation > 8 weeks (32.3% vs 75.5%, P 50 mm (29.0% vs 54.1%, P 8 weeks (OR=7.249, 95%CI=1.998-26.304, P 50 mm (OR=3.896, 95%CI=1.105-13.734, P8 weeks, left atrial diameter >50 mm, left ventricular ejection fraction <50%, and cumulative energy of electrical cardioversion are independent predictors of left atrial appendage stunning. Anticoagulation treatment should be individualized for patients undergoing electrical cardioversion to reduce the risk of both cardioversion-related thromboembolic events and hemorrhagic complications caused by warfarin treatment.

  16. Overlay Technique for Transcatheter Left Atrial Appendage Closure.

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    Li, Shuang; Zhu, Mengyun; Lu, Yunlan; Tang, Kai; Zhao, Dongdong; Chen, Wei; Xu, Yawei

    2015-08-01

    The Overlay technique is popular in peripheral artery interventions, but not in coronary or cardiac structural procedures. We present an initial experience using three-episode overlays during a transcatheter left atrial appendage closure. The first overlay was applied to facilitate advancement of the delivery sheath into left atrium. The second overlay was used to navigate the advancement of prepped delivery system containing the compressed occluder into its optimal position in the left atrium. The third overlay facilitated the real-time deployment of the closure device. This case report demonstrates the effectiveness of the overlay technique in facilitating each step of the transcatheter left atrial appendage closure. Copyright © 2015 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  17. Possible role for cryoballoon ablation of right atrial appendage tachycardia when conventional ablation fails.

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    Amasyali, Basri; Kilic, Ayhan

    2015-06-01

    Focal atrial tachycardia arising from the right atrial appendage usually responds well to radiofrequency ablation; however, successful ablation in this anatomic region can be challenging. Surgical excision of the right atrial appendage has sometimes been necessary to eliminate the tachycardia and prevent or reverse the resultant cardiomyopathy. We report the case of a 48-year-old man who had right atrial appendage tachycardia resistant to multiple attempts at ablation with use of conventional radiofrequency energy guided by means of a 3-dimensional mapping system. The condition led to cardiomyopathy in 3 months. The arrhythmia was successfully ablated with use of a 28-mm cryoballoon catheter that had originally been developed for catheter ablation of paroxysmal atrial fibrillation. To our knowledge, this is the first report of cryoballoon ablation without isolation of the right atrial appendage. It might also be an alternative to epicardial ablation or surgery when refractory atrial tachycardia originates from the right atrial appendage.

  18. Percutaneous left atrial appendage closure for stroke prevention

    DEFF Research Database (Denmark)

    De Backer, Ole; Loupis, Anastasia M; Ihlemann, Nikolaj

    2014-01-01

    INTRODUCTION: In atrial fibrillation (AF) patients with an increased stroke risk, oral anticoagulation (OAC) is the standard treatment for stroke prevention. However, this therapy carries a high risk of major bleeding. Percutaneous closure of the left atrial appendage (LAA) is suggested as an alt......INTRODUCTION: In atrial fibrillation (AF) patients with an increased stroke risk, oral anticoagulation (OAC) is the standard treatment for stroke prevention. However, this therapy carries a high risk of major bleeding. Percutaneous closure of the left atrial appendage (LAA) is suggested...... as an alternative option for stroke prevention in AF patients with contraindication(s) for OAC treatment. MATERIAL AND METHODS: A total of 42 patients underwent percutaneous LAA closure. In this report, we describe our experience with this procedure. RESULTS: The patients treated were AF patients with a high stroke...... risk (CHADS-VASc 4.5±1.4) and contra-indication(s) for OAC and/or a high bleeding risk (HAS-BLED 3.7±0.9). A history of intracerebral bleeding was the most common reason for LAA closure. Successful implantation was obtained in 41 of 42 patients. One major peri-procedural complication occurred; a major...

  19. Amplatzer Amulet left atrial appendage occluder entrapment through mitral valve.

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    González-Santos, Jose María; Arnáiz-García, María Elena; Arribas-Jiménez, Antonio; López-Rodríguez, Javier; Rodríguez-Collado, Javier; Vargas-Fajardo, María del Carmen; Dalmau-Sorlí, María José; Bueno-Codoñer, María Encarnación; Arévalo-Abascal, R Adolfo

    2013-11-01

    We report on a 77-year-old woman in whom percutaneous left atrial appendage (LAA) closure was performed. The patient had a left atrial myxoma resection 3 years previously, and 2 years later, she suffered a transient ischemic attack. Atrial fibrillation was detected and anticoagulation therapy was established. An episode of intracranial bleeding forced interruption of anticoagulation. Thus, percutaneous LAA closure with an Amplatzer Amulet LAA Occluder (St Jude Medical) was proposed. During the procedure, the LAA occluder migrated and became trapped in the mitral valve. Secondary massive mitral regurgitation and hemodynamic instability forced emergent cardiac surgery. Successful removal of the Amplatzer Amulet LAA Occluder was achieved. Copyright © 2013 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  20. Navx-guided Cryoablation of Atrial Tachycardia Inside the Left Atrial Appendage

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    Pandozi, Claudio; Galeazzi, Marco; Lavalle, Carlo; Ficili, Sabina; Russo, Maurizio; Santini, Massimo

    2010-01-01

    Radiofrequency ablation procedures inside the left atrial appendage (LAA) are likely to involve dangerous complications because of a high thrombogenic effect. Cryoablation procedures are supposed to be safer. We describe two cases of successful cryoablation procedures. Two NavX-guided cryoablations of permanent focal atrial arrhythmias arising from the LAA were performed. Left atrial reconstruction and mapping allowed the zone of the earliest atrial potential to be recorded; the entire course of the ablation catheter was monitored. The arrhythmias were successfully ablated; no thrombotic complications were observed. PMID:21346824

  1. Left atrial appendage occlusion for stroke prevention in atrial fibrillation in Europe

    DEFF Research Database (Denmark)

    Lip, Gregory Y.H.; Dagres, Nikolaos; Proclemer, Alessandro;

    2013-01-01

    The purpose of this EP wire survey was to assess clinical practice in relation to the use of left atrial appendage occlusion (LAAO) devices for stroke prevention in atrial fibrillation (AF) among members of the European Heart Rhythm Association research network. The average number of performed LA...... are most often performed by interventional cardiologists. Experience varied widely, and this was reflected in the wide range of thromboembolic and procedural (tamponade, bleeding) complications reported by the respondents to this EP wire survey....

  2. Left atrial appendage closure devices for cardiovascular risk reduction in atrial fibrillation patients

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    Cruz-Gonzalez I

    2015-05-01

    Full Text Available Ignacio Cruz-Gonzalez,* Juan Carlos Rama-Merchan,* Javier Rodriguez-Collado, Javier Martin-Moreiras, Alejandro Diego-Nieto, Antonio Arribas-Jimenez, Pedro Luís SanchezDepartment of Cardiology, University Hospital of Cardiology and IBSAL, Salamanca, Spain *Ignacio Cruz-Gonzalez and Juan Carlos Rama-Merchan have contributed equally to this work and should be considered co-first authors Abstract: Atrial fibrillation (AF is the most common sustained arrhythmia in clinical practice. AF is associated with a 4–5-fold increased risk of stroke and systemic embolism. Oral anticoagulant is the first-line therapy for this purpose, but it has various limitations and is often contraindicated or underutilized. Autopsy and surgical data have suggested that 90% of atrial thrombi in nonvalvular AF patients originate from the left atrial appendage, leading to the development of percutaneous closure for thromboembolic prevention. This paper examines the current evidence on left atrial appendage closure devices for cardiovascular risk reduction in AF patients. Keywords: atrial fibrillation, left atrial appendage, stroke, oral anticoagulant, percutaneous closure, thromboembolic prevention

  3. Hemostasis of Left Atrial Appendage Bleed With Lariat Device

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    Amena Hussain, MD

    2014-09-01

    Full Text Available New devices designed for minimally invasive closure of the left atrial appendage (LAA may be a viable alternative for patients in whom anticoagulation is considered high risk. The Lariat (Sentreheart, Redwood City, CA, which is currently FDA-approved for percutaneous closure of tissue, requires both trans-septal puncture and epicardial access. However it requires no anticoagulation after the procedure. Here we describe a case of effusion and tamponade during a Lariat procedure with successful completion of the case and resolution of the effusion.

  4. Right Atrial Appendage Aneurysm in a Newborn Diagnosed with Fetal Echocardiography

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    Yartaşı Tik, Elif; Öztarhan, Kazım; Dedeoğlu, Reyhan; Çetinkaya, Merih

    2016-01-01

    Right atrial appendage aneurysm is a very rare condition which can be asymptomatic or can cause arrhythmia or life-threatening thromboembolism. We report a case of newborn with right atrial appendage aneurysm who was diagnosed with fetal echocardiography. Anticoagulant therapy was applied to prevent thromboembolism and he is still going on follow-up without any complaint. PMID:27703828

  5. Role of Imaging in Left Atrial Appendage Occlusion

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    Mathieu Lempereur

    2017-04-01

    Full Text Available Percutaneous left atrial appendage (LAA occlusion is now a valid alternative to long-term oral anticoagulation in patients with non-valvular atrial fibrillation at high thrombo-embolism risk, especially for patients who are considered ineligible for anticoagulation. The most frequently used occluders worldwide include the WATCHAMN (Boston Scientific, Natick, MA, USA and the Amplatzer Cardiac Plug or Amulet (St. Jude Medical/Abbott, St Paul, MN, USA devices. Multimodality imaging is key in the understanding of 3D aspects of the LAA and surrounding structures anatomy. Imaging is essential for procedural planning, during each step of the procedure and for device surveillance after implantation. Multimodality imaging, including 2D/3D echocardiography, fluoroscopy, and cardiac computed tomography can increase the safety and efficacy of the procedure.

  6. Fibrosis and electrophysiological characteristics of the atrial appendage in patients with atrial fibrillation and structural heart disease

    NARCIS (Netherlands)

    Brakel, T.J. van; Krieken, T. van der; Westra, S.W.; Laak, J.A.W.M. van der; Smeets, J.L.R.M.; Swieten, H.A. van

    2013-01-01

    PURPOSE: This study was conducted to investigate the degree of fibrosis in atrial appendages of patients with and without atrial fibrillation (AF) undergoing cardiac surgery. In addition, we hypothesized that areas of atrial fibrosis can be identified by electrogram fractionation and low voltage for

  7. Presence of accessory left atrial appendage/diverticula in a population with atrial fibrillation compared with those in sinus rhythm: a retrospective review.

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    Troupis, John; Crossett, Marcus; Scneider-Kolsky, Michal; Nandurkar, Dee

    2012-02-01

    Accessory left atrial appendages and atrial diverticula have an incidence of 10-27%. Their association with atrial fibrillation needs to be confirmed. This study determined the prevalence, number, size, location and morphology of accessory left atrial appendages/atrial diverticula in patients with atrial fibrillation compared with those in sinus rhythm. A retrospective analysis of 47 consecutive patients with atrial fibrillation who underwent 320 multidetector Coronary CT angiography (CCTA) was performed. A random group of 47 CCTA patients with sinus rhythm formed the control group. The presence, number, size, location and morphology of accessory left atrial appendages and atrial diverticula in each group were analysed. Twenty one patients had a total of 25 accessory left atrial appendages and atrial diverticula in the atrial fibrillation group and 22 patients had a total of 24 accessory left atrial appendages and atrial diverticula in the sinus rhythm group. Twenty-one atrial diverticula were identified in 19 patients in the atrial fibrillation group and 19 atrial diverticula in 17 patients in the sinus rhythm group. The mean length and width of accessory left atrial appendage was 6.9 and 4.7 mm, respectively in the atrial fibrillation group and 12 and 4.6 mm, respectively, in the sinus rhythm group, P = ns (not significant). The mean length and width of atrial diverticulum was 4.7 and 3.6 mm, respectively in the atrial fibrillation group and 6.2 and 5 mm, respectively in the sinus rhythm group (P = ns). Eighty-four % and 96% of the accessory left atrial appendages/atrial diverticula in the atrial fibrillation and sinus rhythm groups were located along the right anterosuperior left atrial wall. Accessory left atrial appendages and atrial diverticula are common structures with similar prevalence in patients with atrial fibrillation and sinus rhythm.

  8. Left atrial appendage in acute coronary syndromes: small but not insignificant

    Institute of Scientific and Technical Information of China (English)

    Mingpeng SHE

    2005-01-01

    @@ In this issue of Journal of Geriatric Cardiology, Dr.Piotrowski and colleagues explored the function of the left atrial appendage (LAA)-a small, blind-ended structure of the heart which has been often ignored by cardiologists.1

  9. Left atrial appendage occlusion with the Amplatzer Amulet for stroke prevention in atrial fibrillation: the first case in Greece.

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    Tzikas, Apostolos; Karagounis, Lambros; Bouktsi, Maria; Drevelegas, Antonios; Parcharidou, Despina; Ioannidis, Stathis; Krasopoulos, George; Giannakoulas, George

    2013-01-01

    Left atrial appendage (LAA) occlusion has been introduced into clinical practice as a valuable alternative to oral anticoagulation for stroke prevention in patients with non-valvular atrial fibrillation. In this case presentation we describe the first LAA occlusion in Greece using the Amplatzer Amulet device. We also briefly discuss issues related to procedural safety and multimodality imaging for LAA occlusion.

  10. Closure of Left Atrial Appendage With Persistent Distal Thrombus Using an Amplatzer Amulet Occluder.

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    Lange, Mathias; Bültel, Helmut; Weglage, Heinrich; Löffeld, Patrick; Wichter, Thomas

    2016-09-01

    A 73-year-old patient with permanent atrial fibrillation presented for left atrial appendage (LAA) occlusion. Transesophageal echocardiography demonstrated a thrombus in the distal LAA. This image series illustrates a "no touch" technique that was used to ensure successful implantation of an Amplatzer Amulet LAA occlusion device without the use of an embolization protection system.

  11. Rationale of cerebral protection devices in left atrial appendage occlusion.

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    Meincke, Felix; Spangenberg, Tobias; Kreidel, Felix; Frerker, Christian; Virmani, Renu; Ladich, Elena; Kuck, Karl-Heinz; Ghanem, Alexander

    2017-01-01

    Aims of this case-series were to assess the feasibility of cerebral protection devices in interventional left atrial appendage occlusion (iLAAO) procedures and to yield insight into the pathomorphological correlate of early, procedural cerebral embolization during iLAAO. Five consecutive patients underwent iLLO flanked by the Sentinel CPS® (Claret Medical, Inc., Santa Rosa, CA) cerebral protection system. Placement and recapture of the Sentinel(®) device as well as the iLAAO were successful and safe in all cases. Histomorphometric analysis of the collected filters showed embolized debris in all patients. Acute thrombus was found in three patients, organizing thrombus in four. Interestingly, two patients had endocardial or myocardial tissue in their filters. Cerebral protection during iLAAO with the Sentinel CPS(®) device is feasible. Furthermore, this dataset identifies the formation and embolization of thrombus and cardiac tissue as emboligeneic sources and potential future targets to reduce procedural complications. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  12. Isomerism of the atrial appendages in the fetus.

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    Ho, S Y; Cook, A; Anderson, R H; Allan, L D; Fagg, N

    1991-01-01

    Thirty hearts from fetuses with visceral heterotaxy were examined to determine the range of cardiac malformations. By examining the morphology of the atrial appendages, 20 hearts were identified as having left isomerism (67%) and 10 hearts right isomerism (33%). Fifteen of the hearts with left isomerism had biventricular atrioventricular connections and five had univentricular atrioventricular connections. All 10 hearts with right isomerism had biventricular atrioventricular connections. Flow to the pulmonary arteries was obstructed or occluded in 6 hearts with left isomerism (30%) and 7 hearts with right isomerism (70%). Obstruction to aortic flow was present in 4 hearts with left isomerism (20%). Anomalies of the systemic and pulmonary veins were common in both groups. The suprarenal portion of the inferior caval vein was interrupted in 11 hearts with left isomerism (55%) and 1 heart with right isomerism (10%). Atrioventricular septal defect was present in 13 hearts with left isomerism (65%) and 9 hearts with right isomerism (90%). The arrangement of the liver or stomach in each group was not consistent, nor was the status of the spleen. The constellations of cardiac malformations in both groups corresponded to those known in postnatal life and similar guidelines for their identification were applicable.

  13. Combined percutaneous balloon mitral valvuloplasty and left atrial appendage occlusion device implantation for rheumatic mitral stenosis and atrial fibrillation

    Energy Technology Data Exchange (ETDEWEB)

    Murdoch, Dale, E-mail: dale_murdoch@health.qld.gov.au [The Prince Charles Hospital, Brisbane (Australia); The University of Queensland, Brisbane (Australia); McAulay, Laura [The Prince Charles Hospital, Brisbane (Australia); Walters, Darren L. [The Prince Charles Hospital, Brisbane (Australia); The University of Queensland, Brisbane (Australia)

    2014-11-15

    Rheumatic heart disease is a common cause of cardiovascular morbidity and mortality worldwide, mostly in developing countries. Mitral stenosis and atrial fibrillation often coexist, related to both structural and inflammatory changes of the mitral valve and left atrium. Both predispose to left atrial thrombus formation, commonly involving the left atrial appendage. Thromboembolism can occur, with devastating consequences. We report the case of a 62 year old woman with rheumatic heart disease resulting in mitral stenosis and atrial fibrillation. Previous treatment with warfarin resulted in life-threatening gastrointestinal bleeding and she refused further anticoagulant therapy. A combined procedure was performed, including percutaneous balloon mitral valvuloplasty and left atrial appendage occlusion device implantation with the Atritech® Watchman® device. No thromboembolic or bleeding complications were encountered at one year follow-up. Long-term follow-up in a cohort of patients will be required to evaluate the safety and efficacy of this strategy.

  14. Surgical Left Atrial Appendage Exclusion Does Not Impair Left Atrial Contraction Function: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Gijs E. De Maat

    2015-01-01

    Full Text Available Background. In order to reduce stroke risk, left atrial appendage amputation (LAAA is widely adopted in recent years. The effect of LAAA on left atrial (LA function remains unknown. The objective of present study was to assess the effect of LAAA on LA function. Methods. Sixteen patients with paroxysmal AF underwent thoracoscopic, surgical PVI with LAAA (LAAA group, and were retrospectively matched with 16 patients who underwent the same procedure without LAA amputation (non-LAAA group. To objectify LA function, transthoracic echocardiography with 2D Speckle Tracking was performed before surgery and at 12 months follow-up. Results. Mean age was 57 ± 9 years, 84% were male. Baseline characteristics did not differ significantly except for systolic blood pressure (p=0.005. In both groups, the contractile LA function and LA ejection fraction were not significantly reduced. However, the conduit and reservoir function were significantly decreased at follow-up, compared to baseline. The reduction of strain and strain rate was not significantly different between groups. Conclusions. In this retrospective, observational matched group comparison with a convenience sample size of 16 patients, findings suggest that LAAA does not impair the contractile LA function when compared to patients in which the appendage was unaddressed. However, the LA conduit and reservoir function are reduced in both the LAAA and non-LAAA group. Our data suggest that the LAA can be removed without late LA functional consequences.

  15. Left atrial appendage occlusion: initial experience with the Amplatzer™ Amulet™.

    Science.gov (United States)

    Freixa, Xavier; Abualsaud, Ali; Chan, Jason; Nosair, Mohamed; Tzikas, Apostolos; Garceau, Patrick; Basmadjian, Arsène; Ibrahim, Réda

    2014-07-01

    The Amplatzer™ Amulet™ (Amulet) is the evolution of the Amplatzer™ Cardiac Plug, a dedicated device for percutaneous left atrial appendage (LAA) occlusion. The new device has been designed to facilitate the implantation process, improve the sealing performance and further reduce the risk of complications. The objective of the study was to describe the initial experience with the Amplatzer Amulet for percutaneous LAA occlusion. This was a prospective single-center study of patients undergoing percutaneous LAA occlusion. The indication for LAA closure was a formal contraindication for oral anticoagulation or previous history of stroke due to INR lability. All procedures were done under general anesthesia and transesophageal echocardiography (TEE) guidance. Transthoracic echocardiography was performed 24h after the procedure in order to rule out procedural complications before discharge. Further follow-up was done with a clinical visit and TEE at 1-3 months. Between July-2012 and June-2013, 25 patients with a mean CHA2DS2-VASC of 4.3 ± 1.7 underwent LAA occlusion with the Amplatzer Amulet. The device was successfully implanted in 24 patients (96%) without any procedural stroke, pericardial effusion or device embolization. None of the patients presented any clinical event at follow-up. Follow-up TEE showed complete LAA sealing in all patients with no residual leaks >3mm and no device embolization. One patient (4.1%) presented a device thrombosis at follow-up without clinical expression. In this initial series of patients, the Amulet showed a remarkable acute and short-term performance in terms of feasibility and safety as depicted by the high successful implantation rate and the low incidence of complications. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  16. A giant left atrial appendage aneurysm with a large pinball-like thrombus in a 2 year old

    OpenAIRE

    Simarjot Singh Sarin; Tripat Bindra; Gurpreet S Chhabra

    2012-01-01

    Congenital left atrial appendage aneurysm is very rare. We describe a giant left atrial appendage aneurysm with a pinball-like mobile thrombus in a 2-year-old child with cardioembolic stroke. Patient underwent successful surgical resection of the aneurysm.

  17. Cardiac Plug I and Amulet Devices: Left Atrial Appendage Closure for Stroke Prophylaxis in Atrial Fibrillation.

    Science.gov (United States)

    Parashar, Akhil; Tuzcu, E Murat; Kapadia, Samir R

    2015-01-01

    Percutaneous left atrial appendage (LAA) occlusion has emerged as an exciting and effective modality for stroke prophylaxis in patients with non-valvular atrial fibrillation who are deemed too high risk for anticoagulation with warfarin or newer anticoagulants. The Amplatzer devices have been used in LAA occlusion for more than a decade, starting with off label use of an atrial septal occluder device for LAA occlusion. This was followed by introduction of a dedicated Amplatzer cardiac plug (ACP) 1 for LAA occlusion, and more recently, the second generation Amulet device, with reported better stability enhancing features, has been introduced. Both these devices are widely used outside the United States, however in the US only the WATCHMAN device has been FDA approved. Unlike the WATCHMAN device, where the evidence is continuously building as the data from two pivotal randomized controlled trials are emerging, most of the evidence for ACP devices is from pooled multicenter registry data. In this article, we review the device design, implantation techniques and the most recently published evidence for both the Amplatzer cardiac plug 1 and the newer Amulet device. Our goal is to summarize the most recent literature and discuss the current role of the Amplatzer devices in the exciting and rapidly growing field of percutaneous LAA occlusion.

  18. [Giant congenital intrapericardial left atrial appendage aneurysm: about a case and review of the literature].

    Science.gov (United States)

    Zhari, Bouchra; Bellamlih, Habib; Boumdine, Hassan; Amil, Touriya; Bamous, Mehdi; En-Nouali, Hassan

    2016-01-01

    Left atrial appendage aneurysm is a very rare heart anomaly. It may be congenital or acquired, secondary to inflammatory or degenerative processes. Most cases are asymptomatic. The prevalence of these lesions in pediatric age has been very rarely reported. As it can cause potentially fatal arrhythmias or thrombus, surgery is required immediately after diagnosis. This study reports the case of a 14-year-old boy with rapidly progressive dyspnea, palpitations, sensation of repetitive dizziness and fainting, in whom congenital left atrial appendage aneurysm was detected. Diagnosis was based on coronary CTA data. The patient was successfully treated with surgical resection of the aneurysm.

  19. Percutaneous left atrial appendage closure: Technical aspects and prevention of periprocedural complications with the watchman device

    Institute of Scientific and Technical Information of China (English)

    Sven; M?bius-Winkler; Nicolas; Majunke; Marcus; Sandri; Norman; Mangner; Axel; Linke; Gregg; W; Stone; Ingo; D?hnert; Gerhard; Schuler; Peter; B; Sick

    2015-01-01

    Transcatheter closure of the left atrial appendage has been developed as an alternative to chronic oral anticoagulation for stroke prevention in patients with atrial fibrillation, and as a primary therapy for patients with contraindications to chronic oral anticoagulation. The promise of this new intervention compared with warfarin has been supported by several, small studies and two pivotal randomized trial with the Watchman Device. The results regarding risk reduction for stroke have been favourable although acute complications were not infrequent. Procedural complications, which are mainly related to transseptal puncture and device implantation, include air embolism, pericardial effusions/tamponade and device embolization. Knowledge of nature, management and prevention of complications should minimize the risk of complications and allow transcatheter left atrial appendage closure to emerge as a therapeutic option for patients with atrial fibrillation at risk for cardioembolic stroke.

  20. Age-related changes in morphology of left atrial appendage in patients with atrial fibrillation.

    Science.gov (United States)

    Hirata, Yukina; Kusunose, Kenya; Yamada, Hirotsugu; Shimizu, Rikuto; Torii, Yuta; Nishio, Susumu; Saijo, Yoshihito; Takao, Shoichiro; Soeki, Takeshi; Sata, Masataka

    2017-08-14

    The purpose of this study was to evaluate the relationship between age and frequency of left atrial appendage (LAA) morphology in patients with atrial fibrillation (AF) compared with sinus rhythm (SR). We enrolled 145 AF patients, and 199 SR patients for the control group without any cardiovascular disease. LAA volume index (LAAVi) and morphology were assessed by electrocardiogram-gated computed tomography angiography. LAA morphology was classified into "chicken wing" or "non-chicken wing" according to the previously described classification. There was no significant trend in frequency of non-chicken wing morphology among ages in the SR group (p = 0.36 for trend), whereas the frequency was negatively related to age in the AF group (p = 0.002 for trend). In multivariable logistic regression, age > 65 (odds ratio [OR] 0.42, p = 0.002) and duration of AF (OR 0.53, p = 0.010) and LAAVi (OR 0.62, p = 0.017) were independent factors of non-chicken wing LAA morphology in the AF group. LAA morphology is affected by age, especially in patients with AF. When we utilize non-chicken wing LAA morphology as a stroke risk factor in patients with AF, we should pay attention to their age.

  1. Left atrial appendage occlusion in high-risk patients with non-valvular atrial fibrillation.

    Science.gov (United States)

    Berti, Sergio; Pastormerlo, Luigi Emilio; Rezzaghi, Marco; Trianni, Giuseppe; Paradossi, Umberto; Cerone, Elisa; Ravani, Marcello; De Caterina, Alberto Ranieri; Rizza, Antonio; Palmieri, Cataldo

    2016-12-15

    Percutaneous left atrial appendage (LAA) occlusion has been developed as a viable option for stroke and thromboembolism prevention in patients with non-valvular atrial fibrillation (NVAF) and at high risk for cerebral cardioembolic events. Data on device implantation and long-term follow-up from large cohorts are limited. 110 consecutive patients with NVAF and contraindications to oral anticoagulants (OACs) underwent LAA occlusion procedures and achieved a longer than 1 year follow-up. All patients were enrolled in a prospective registry. Procedures were performed using the Amplatzer Cardiac Plug or Amulet guided by fluoroscopy and intracardiac echocardiography. Mean age of the population was 77±6 years old; 68 were men. Atrial fibrillation was paroxysmal in 20%, persistent in 15.5% and permanent in 64.5% of cases, respectively. Mean CHA2DS2-VASc and HAS-BLED scores were 4.3±1.3 and 3.4±1, respectively. Technical success (successful deployment and implantation of device) was achieved in 100% of procedures. Procedural success (technical success without major procedure-related complications) was achieved in 96.4%, with a 3.6% rate of major procedural complications (three cases of pericardial tamponade requiring drainage and one case of major bleeding). Mean follow-up was 30±12 months (264 patient-years). Annual rates for ischaemic stroke and for other thromboembolic events were respectively 2.2% and 0%, and annual rate for major bleeding was 1.1%. Our data suggest LAA occlusion in high-risk patients with NVAF not suitable for OACs is feasible and associated with low complication rates as well as low rates of stroke and major bleeding at long-term follow-up. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  2. Impact of electrical cardioversion for atrial fibrillation on left atrial appendage function and spontaneous echo contrast: characterization by simultaneous transesophageal echocardiography.

    Science.gov (United States)

    Grimm, R A; Stewart, W J; Maloney, J D; Cohen, G I; Pearce, G L; Salcedo, E E; Klein, A L

    1993-11-01

    This study assessed the function of the left atrial appendage in the pericardioversion period to gain insights into mechanisms involved in thromboembolism after cardioversion of atrial fibrillation. Systemic embolization associated with electrical cardioversion of atrial fibrillation is thought to originate from the left atrium or left atrial appendage, or both. However, the mechanism involved is poorly understood. We studied left atrial appendage function with transesophageal echocardiography in 20 patients with atrial fibrillation before and after successful electrical cardioversion. We measured left atrial appendage emptying and filling velocities by pulsed wave Doppler echocardiography, characterized Doppler emptying patterns, measured atrial appendage areas and assessed the presence or absence of spontaneous echo contrast or thrombus. Organized left atrial appendage function returned in 16 (80%) of 20 patients immediately after cardioversion. Atrial appendage emptying velocities before cardioversion were greater in patients without (0.39 +/- 0.02 m/s) than in those with (0.25 +/- 0.12 m/s) spontaneous echo contrast (p = 0.045). Furthermore, emptying velocities before cardioversion were significantly greater than late diastolic emptying velocities after cardioversion (0.31 +/- 0.15 vs. 0.14 +/- 0.12 m/s, p = 0.0001), as well as in both the group with (0.25 +/- 0.12 vs. 0.13 +/- 0.13 m/s, p = 0.001) and the group without (0.39 +/- 0.02 vs. 0.15 +/- 0.12 m/s, p = 0.01) spontaneous echo contrast. In addition, left atrial and atrial appendage spontaneous echo contrast developed in 4 of 20 patients and increased in intensity in 3 of 20 patients in the immediate postcardioversion period. Organized left atrial appendage function returns in most patients immediately after cardioversion of atrial fibrillation. However, its function is impaired compared with that before cardioversion. Furthermore, spontaneous echo contrast increased in 7 (35%) of 20 patients after

  3. Left atrial appendage closure in patients with intracranial haemorrhage and atrial fibrillation.

    Science.gov (United States)

    Fayos-Vidal, F; Arzamendi-Aizpurua, D; Millán-Álvarez, X; Guisado-Alonso, D; Camps-Renom, P; Prats-Sánchez, L; Martínez-Domeño, A; Delgado-Mederos, R; Martí-Fàbregas, J

    2017-08-30

    The use of oral anticoagulants in patients with a history of atrial fibrillation (AF) and intracranial haemorrhage (ICH) is controversial on account of the risk of haemorrhagic stroke recurrence. This study presents our experience regarding the safety and efficacy of percutaneous left atrial appendage closure (LAAC), an alternative to anticoagulation in these patients. We conducted a retrospective, single-centre, observational study. LAAC was performed in patients with a history of ICH and non-valvular AF. Risk of ischaemic and haemorrhagic events was estimated using the CHA2DS2-VASc and HAS-BLED scales. We recorded periprocedural complications, IHC recurrence, cerebral/systemic embolism, mortality and use of antithrombotic drugs following the procedure. LAAC was performed in 9 patients (7 men, 2 women) using the AMPLATZER Amulet device in 7 cases and the AMPLATZER Cardiac Plug device in 2. Mean age was 72.7±8.2 years. Time between ICH and LAAC was less than one month in 5 patients and more than one month in 4 patients. Median CHA2DS2-VASc score was 4 (interquartile range of 2.5). Median HAS-BLED score was 3 (interquartile range of 0). No periprocedural complications were recorded. All patients received single anti-platelet therapy (clopidogrel in 5 patients, aspirin in 4) after the procedure; 5 patients received this treatment for 6 months and 4 received it indefinitely. No ischaemic or haemorrhagic events were recorded during follow-up (mean duration of 15 months). In our series, LAAC was found to be safe and effective in patients with a history of ICH who required anticoagulation due to AF. Copyright © 2017 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  4. Left atrial appendage morphology in patients with suspected cardiogenic stroke without known atrial fibrillation.

    Directory of Open Access Journals (Sweden)

    Miika Korhonen

    Full Text Available The left atrial appendage (LAA is the typical origin for intracardiac thrombus formation. Whether LAA morphology is associated with increased stroke/TIA risk is controversial and, if it does, which morphological type most predisposes to thrombus formation. We assessed LAA morphology in stroke patients with cryptogenic or suspected cardiogenic etiology and in age- and gender-matched healthy controls. LAA morphology and volume were analyzed by cardiac computed tomography in 111 patients (74 males; mean age 60 ± 11 years with acute ischemic stroke of cryptogenic or suspected cardiogenic etiology other than known atrial fibrillation (AF. A subgroup of 40 patients was compared to an age- and gender-matched control group of 40 healthy individuals (21 males in each; mean age 54 ± 9 years. LAA was classified into four morphology types (Cactus, ChickenWing, WindSock, CauliFlower modified with a quantitative qualifier. The proportions of LAA morphology types in the main stroke group, matched stroke subgroup, and control group were as follows: Cactus (9.0%, 5.0%, 20.0%, ChickenWing (23.4%, 37.5%, 10.0%, WindSock (47.7%, 35.0%, 67.5%, and CauliFlower (19.8%, 22.5%, 2.5%. The distribution of morphology types differed significantly (P<0.001 between the matched stroke subgroup and control group. The proportion of single-lobed LAA was significantly higher (P<0.001 in the matched stroke subgroup (55% than the control group (6%. LAA volumes were significantly larger (P<0.001 in both stroke study groups compared to controls patients. To conclude, LAA morphology differed significantly between stroke patients and controls, and single-lobed LAAs were overrepresented and LAA volume was larger in patients with acute ischemic stroke of cryptogenic or suspected cardiogenic etiology.

  5. Aneurisma de apêndice atrial esquerdo: diagnóstico ecocardiográfico Left atrial appendage aneurysm: echocardiografic diagnostic

    Directory of Open Access Journals (Sweden)

    Viviane Cordeiro Veiga

    2008-05-01

    Full Text Available O aneurisma de apêndice atrial esquerdo é condição rara que se manifesta freqüentemente por arritmias cardíacas ou tromboembolismo. Relatamos um caso de paciente portador de aneurisma de apêndice atrial esquerdo, diagnosticado pela ecocardiografia e submetido a ressecção cirúrgica.The left atrial appendage aneurysm is a rare condition that frequently manifests itself by heart arrhythmias or thromboembolism. We report the case of a patient with left atrial appendage aneurysm, diagnosed by echocardiography and submitted to surgical resection.

  6. Percutaneous left atrial appendage closure devices: safety, efficacy, and clinical utility

    Directory of Open Access Journals (Sweden)

    Swaans MJ

    2016-09-01

    Full Text Available Martin J Swaans, Lisette IS Wintgens, Arash Alipour,  Benno JWM Rensing, Lucas VA Boersma Department of Cardiology, St. Antonius Hospital, Nieuwegein, the Netherlands Abstract: Atrial fibrillation (AF is the most common arrhythmia treated in the clinical practice. One of the major complications of AF is a thromboembolic cerebral ischemic event. Up to 20% of all strokes are caused by AF. Thromboembolic cerebral ischemic event in patients with AF occurs due to atrial thrombi, mainly from the left atrial appendage (LAA. Prevention of clot formation with antiplatelet agents and especially oral anticoagulants (­vitamin K antagonists or newer oral anticoagulants has been shown to be effective in reducing the stroke risk in patients with AF but has several drawbacks with (major bleedings as the most important disadvantage. Therefore, physical elimination of the LAA, which excludes the site of clot formation by surgical or percutaneous techniques, might be a good alternative. In this review, we discuss the safety, efficacy, and clinical utility of the Watchman™ LAA closure device. Keywords: stroke, left atrial appendage, prevention, atrial fibrillation

  7. Left Atrial Appendage Closure for Atrial Fibrillation Is Safe and Effective After Intracranial or Intraocular Hemorrhage.

    Science.gov (United States)

    Fahmy, Peter; Spencer, Ryan; Tsang, Michael; Gooderham, Peter; Saw, Jacqueline

    2016-03-01

    Atrial fibrillation (AF) affects 1%-2% of the general population and 13% of individuals older than 80 years of age. Anticoagulation has been the mainstay therapy to reduce stroke risk. Patients with previous intracranial hemorrhage (ICH) or intraocular hemorrhage (IOH) are at increased risk of recurrence if anticoagulation is continued or initiated. Left atrial appendage (LAA) closure may obviate the need for long-term anticoagulation in these patients. We report our consecutive series of patients with nonvalvular AF with previous ICH or IOH who underwent LAA closure with the AMPLATZER Cardiac Plug (ACP; St Jude Medical, St Paul, MN), AMPLATZER Amulet, or WATCHMAN (Boston Scientific, Natick, MA) device. Demographics, clinical status, procedural outcomes, and complications were collected at baseline, during the procedure, at 3 months, at 1 year, and annually thereafter. Twenty-six patients with previous ICH (n = 24) or IOH (n = 2) underwent LAA closure (9 with the ACP, 3 with the Amulet, and 7 with the WATCHMAN). The mean age was 76 ± 7 years, and 61.5% were men with a mean CHADS2 (Congestive Heart Failure, Hypertension, Age, Diabetes, Stroke/Transient Ischemic Attack) score of 3.2 ± 1.4 and CHA2DS2-VASc (Congestive Heart Failure, Hypertension, Age [≥ 75 years], Diabetes, Stroke/Transient Ischemic Attack, Vascular Disease, Age [65-74 years], Sex [Female] score) of 4.9 ± 1.7. No procedure-related complications occurred. Mean follow-up was 11.9 ± 13.3 months. One patient died at 13 months (this death was not related to the procedure), and 1 patient had a transient ischemic attack at 20.6 months after the procedure. No ischemic stroke, haemorrhagic stroke, or bleeding problems occurred during follow-up. In our consecutive series, LAA closure was found to be safe and effective in patients with AF and a history of ICH or IOH. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  8. Intra-procedural imaging of the left atrial appendage: implications for closure with the Amplatzer™ cardiac plug.

    Science.gov (United States)

    Sobrino, Ayax; Tzikas, Apostolos; Freixa, Xavier; Pulido, Alicia; Chan, Jason; Garceau, Patrick; Ibrahim, Reda; Basmadjian, Arsène J

    2014-01-01

    To evaluate intra-procedural imaging with transesophageal echocardiography and angiography during left atrial appendage occlusion using the Amplatzer™ Cardiac Plug with regard to sizing and final device shape. Left atrial appendage ostium dimensions and diameter at a depth of 10mm from the ostium were measured by transesophageal echocardiography (0-180°) and angiography (RAO 30° - Cranial 20°) in consecutive patients undergoing left atrial appendage occlusion using the ACP with an oversizing strategy of 10-20% relative to the baseline measurements. After delivery, ACP dimensions were measured and device shape was assessed. Twenty-seven consecutive patients underwent successful uncomplicated left atrial appendage closure with Amplatzer™ Cardiac Plug. We found a significant difference between the largest and smallest left atrial appendage diameter measured with transesophageal echocardiography (22.3±4.2 vs. 18.1±4.1mm, p<0.001). By the end of the procedure (by angiography), ACP had an optimal shape in 17 patients (63%), a strawberry-like shape in 7 patients (26%), and a square-like shape in 3 patients (11%). ACP was oversized on average by 1.5±2.7 and 3.3±2.3mm compared to transesophageal echocardiography and angiography, respectively. The final shape of the device was not significantly associated with the degree of oversizing. We found a considerable variability in the assessment of the left atrial appendage, using transesophageal echocardiography and angiography. The degree of Amplatzer™ Cardiac Plug expansion within the left atrial appendage and the final shape of the device were not associated with the degree of oversizing. Copyright © 2013 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.

  9. Radiofrequency Ablation of a Left Atrial Appendage Tachycardia on ECMO Support

    Directory of Open Access Journals (Sweden)

    Mohsin Khan

    2013-01-01

    Full Text Available Extracorporeal membrane oxygenation (ECMO has been utilized in the pediatric population for cardiogenic shock secondary to medically intractable arrhythmias. There is limited experience with cardiac radiofrequency ablation (RFA on these patients while on ECMO. A 7-year-old girl presented with a tachycardia-mediated cardiomyopathy secondary to a left atrial appendage tachycardia. She suffered a cardiac arrest due to pulseless electrical activity and was placed on ECMO. Due to elevated left atrial pressures and the refractoriness of her arrhythmia to cardioversion and antiarrhythmic therapy, while on ECMO, blade atrial septostomy and radiofrequency ablation were performed. The patient tolerated the procedure well and was successfully decannulated. Her cardiac function normalized within four weeks of the ablation procedure. Twelve months after the procedure, she remains completely well, with no symptoms or tachycardia.

  10. [Implantation of Watchman™ occluder of the left atrial appendage. Tips and tricks].

    Science.gov (United States)

    Israel, Carsten W; Tschishow, Wladimir N; Ridjab, Denio; Kische, Stephan; Buddecke, Julia; Ince, Hüseyin

    2013-03-01

    The implantation of an occluder system for the left atrial appendage (LAA) represents an interesting alternative for patients with atrial fibrillation and a CHA2DS2-VASc-Score ≥ 2 who cannot take permanent anticoagulation for various reasons. As in other left cardiac interventions, there are potentially dangerous possibilities for complications that can limit the advantages of this therapy. This overview summarizes practical tips and tricks at the implantation of a Watchman™ occluder which may help to minimize the complication rate. These hints refer to peri-interventional anticoagulation as well as transseptal puncture (technique, imaging), exchange of catheters, left atrial pressure, intubation and fluoroscopy of the LAA, preparation of the device and sheath, delivery of the Watchman™ device, confirmation of optimal position, and partial or complete recapture. If these precautions are considered, the complication rate at implantation of a Watchman™ occluder should be  95 %.

  11. Electron-beam computed tomography findings of left atrial appendage in patients with cardiogenic cerebral embolism

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, Makiko; Takahashi, Satoshi; Yonezawa, Hisashi [Iwate Medical Univ., Morioka (Japan). School of Medicine

    2002-04-01

    We studied electron-beam computed tomography (EBCT) findings in the left atrial appendage of 72 patients with cerebral embolism [27 in the acute phase (<48 hours) and 45 in the chronic phase], 9 cases with nonvalvular atrial fibrillation (NVAF) but without stroke, and 13 controls. EBCT was performed in the early (during injection of contrast medium), late-1 (5 min after injection), and-2 (10 min after injection) phases. In the acute phase patients, 41% showed filling defect (FD) in the early phase alone (FDE), 15% showed FD until late phase-1 (FDL-1), and 15% showed FD until late phase-2 (FDL-2). The chronic phase patients showed FDE in 33% of cases, FDL-1 in 8% and FDL-2 11%. Only FDE was observed in 44% in NVAF cases without stroke. No FDs were observed in controls. Flow velocity in the appendage measured by transesophageal echocardiography was 23{+-}10 cm/sec in 21 FDE cases, 14{+-}3 cm/sec in 3 FDL-1 cases, 29{+-}23 cm/sec in 4 FDL-2 cases, significantly lower in comparison with 58{+-}25 cm/s in the 23 cases with no FD. FDL-1 and -2 suggested severe stasis or presence of thrombus in the appendage, which indicated high risk of embolism slower the movement of MES through the sample volume. (author)

  12. Thrombus-in-Transit Entrapped in a Partially Ligated Left Atrial Appendage

    Directory of Open Access Journals (Sweden)

    Farideh Roshanali

    2015-10-01

    Full Text Available A 54-year-old man referred to our center with Barlow’s disease and severe mitral regurgitation. He had atrial fibrillation (AF rhythm, with a mildly enlarged left atrium (LA. Transesophageal echocardiography (TEE showed no clot in the LA and LA appendage; there was only mild spontaneous echo contrast in the LA appendage. The patient underwent mitral valve repair and the Maze operation, during which the LA appendage was ligated with the double suture technique. He was discharged from the hospital in good condition and in sinus rhythm. He was recommended Warfarin and PT control.One month later, he returned with the complaint of vision loss twice in the left eye each time for a few seconds. The AF rhythm had returned.TEE demonstrated a fresh and mobile thrombus entrapped in the LA appendage with a small portion in the LA (Figures 1 and 2. Laboratory tests showed therapeutic international normalized ratio (INR. The patient refused re- operation.  Plavix was added to his medication, and he was discharged.

  13. Left Atrial Appendage: Physiology, Pathology, and Role as a Therapeutic Target

    Directory of Open Access Journals (Sweden)

    Damiano Regazzoli

    2015-01-01

    Full Text Available Atrial fibrillation (AF is the most common clinically relevant cardiac arrhythmia. AF poses patients at increased risk of thromboembolism, in particular ischemic stroke. The CHADS2 and CHA2DS2-VASc scores are useful in the assessment of thromboembolic risk in nonvalvular AF and are utilized in decision-making about treatment with oral anticoagulation (OAC. However, OAC is underutilized due to poor patient compliance and contraindications, especially major bleedings. The Virchow triad synthesizes the pathogenesis of thrombogenesis in AF: endocardial dysfunction, abnormal blood stasis, and altered hemostasis. This is especially prominent in the left atrial appendage (LAA, where the low flow reaches its minimum. The LAA is the remnant of the embryonic left atrium, with a complex and variable morphology predisposing to stasis, especially during AF. In patients with nonvalvular AF, 90% of thrombi are located in the LAA. So, left atrial appendage occlusion could be an interesting and effective procedure in thromboembolism prevention in AF. After exclusion of LAA as an embolic source, the remaining risk of thromboembolism does not longer justify the use of oral anticoagulants. Various surgical and catheter-based methods have been developed to exclude the LAA. This paper reviews the physiological and pathophysiological role of the LAA and catheter-based methods of LAA exclusion.

  14. Peri-procedural silent cerebral infarcts after left atrial appendage occlusion.

    Science.gov (United States)

    Laible, M; Möhlenbruch, M; Horstmann, S; Pfaff, J; Geis, N A; Pleger, S; Schüler, S; Rizos, T; Bendszus, M; Veltkamp, R

    2017-01-01

    To determine the rate of peri-interventional silent brain infarcts after left atrial appendage occlusion (LAAO). In this prospective, uncontrolled single-center pilot study, consecutive patients with atrial fibrillation undergoing LAAO between July 2013 and January 2016 were included. The Amplatzer Cardiac Plug, WATCHMAN or Amulet device was used. A neurological examination and cranial magnetic resonance imaging (MRI) were performed within 48 h before and after the procedure. MRI was evaluated for new diffusion-weighted imaging (DWI) hyperintensities, cerebral microbleeds (CMBs) and white-matter lesions (WMLs). Left atrial appendage occlusion was performed in 21 patients (mean age, 73.2 ± 9.5 years). Main reasons for LAAO were previous intracerebral hemorrhage (n = 11) and major systemic bleeding (n = 6). No clinically overt stroke occurred peri-interventionally. After the intervention, one patient had a small cerebellar hyperintensity on DWI (4.8%; 95% confidence interval, 0.0-14.3) that was not present on the MRI 1 day before the procedure. Among 11 patients with available MRI just before LAAO, there were no significant changes in the number of CMBs and the severity of WMLs after LAAO. This study of peri-interventional MRI in LAAO suggests a low rate of silent peri-procedural infarcts in this elderly population. Confirmation in larger studies is needed. © 2016 EAN.

  15. Left atrial appendage thrombus with resulting stroke post-RF ablation for atrial fibrillation in a patient on dabigatran.

    LENUS (Irish Health Repository)

    Lobo, R

    2015-11-01

    Dabigatran etexilate is licensed for use in prevention of deep venous thromboembolism and in prevention of stroke and systemic embolism in nonvalvular atrial fibrillation (AF). It has also been used in patients for other indications as a substitute for warfarin therapy because it requires no monitoring; one group being patients undergoing radiofrequency (RF), ablation for AF, although there have been no consensus guidelines with regards to dosage and timing of dose. We report the case of a patient with documentary evidence of left atrial appendage (LAA) thrombus formation and neurological sequelae post-RF ablation despite being on dabigatran. This case highlights the concern that periprocedural dabigatran may not provide adequate protection from development of LAA thrombus and that a standardised protocol will need to be developed and undergo large multicentre trials before dabigatran can be safely used for patients undergoing RF-ablation.

  16. Cardiac embolism after implantable cardiac defibrillator shock in non-anticoagulated atrial fibrillation: The role of left atrial appendage occlusion.

    Science.gov (United States)

    Freixa, Xavier; Andrea, Rut; Martín-Yuste, Victoria; Fernández-Rodríguez, Diego; Brugaletta, Salvatore; Masotti, Mónica; Sabaté, Manel

    2014-04-26

    Cardioembolic events are one of the most feared complications in patients with non-valvular atrial fibrillation (NVAF) and a formal contraindication to oral anticoagulation (OAC). The present case report describes a case of massive peripheral embolism after an implantable cardiac defibrillator (ICD) shock in a patient with NVAF and a formal contraindication to OAC due to previous intracranial hemorrhage. In order to reduce the risk of future cardioembolic events, the patient underwent percutaneous left atrial appendage (LAA) occlusion. A 25 mm Amplatzer™ Amulet was implanted and the patient was discharged the following day without complications. The potential risk of thrombus dislodgement after an electrical shock in patients with NVAF and no anticoagulation constitutes a particular scenario that might be associated with an additional cardioembolic risk. Although LAA occlusion is a relatively new technique, its usage is rapidly expanding worldwide and constitutes a very valid alternative for patients with NVAF and a formal contraindication to OAC.

  17. Thromboembolism Prevention via Transcatheter Left Atrial Appendage Closure with Transeosophageal Echocardiography Guidance

    Directory of Open Access Journals (Sweden)

    John Palios

    2014-01-01

    Full Text Available Atrial fibrillation (AF is an independent risk factor for stroke. Anticoagulation therapy has a risk of intracerebral hemorrhage. The use of percutaneous left atrial appendage (LAA closure devices is an alternative to anticoagulation therapy. Echocardiography has a leading role in LAA closure procedure in patient selection, during the procedure and during followup. A comprehensive echocardiography study is necessary preprocedural in order to identify all the lobes of the LAA, evaluate the size of the LAA ostium, look for thrombus or spontaneous echo contrast, and evaluate atrial anatomy, including atrial septal defect and patent foramen ovale. Echocardiography is used to identify potential cardiac sources of embolism, such as atrial septal aneurysm, mitral valve disease, and aortic debris. During the LAA occlusion procedure transeosophageal echocardiography provides guidance for the transeptal puncture and monitoring during the release of the closure device. Procedure-related complications can be evaluated and acceptable device release criteria such as proper position and seating of the occluder in the LAA, compression, and stability can be assessed. Postprocedural echocardiography is used for followup to assess the closure of the LAA ostium. This overview paper describes the emerging role of LAA occlusion procedure with transeosophageal echocardiography guidance as an alternative to anticoagulation therapy in patients with AF.

  18. Fibrosis and electrophysiological characteristics of the atrial appendage in patients with atrial fibrillation and structural heart disease.

    Science.gov (United States)

    van Brakel, Thomas J; van der Krieken, Thomas; Westra, Sjoerd W; van der Laak, Jeroen A; Smeets, Joep L; van Swieten, Henry A

    2013-11-01

    This study was conducted to investigate the degree of fibrosis in atrial appendages of patients with and without atrial fibrillation (AF) undergoing cardiac surgery. In addition, we hypothesized that areas of atrial fibrosis can be identified by electrogram fractionation and low voltage for potential ablation therapy. Interstitial fibrosis from right (RAA) and/or left atrial appendages (LAA) was studied in patients with sinus rhythm (SR, n = 8), paroxysmal (n = 21), and persistent AF (n = 20) undergoing coronary artery bypass and/or aortic or mitral valve surgery. Atrial fibrosis quantification was performed with Masson trichrome staining. Intraoperative bipolar epicardial electrophysiological measurements were performed to correlate fibrosis to electrogram fractionation, voltage, and AF cycle length. The average degree of fibrosis was 11.2 ± 7.2 % in the LAA and 22.8 ± 7.6 % in the RAA (p Fibrosis was not significantly higher in paroxysmal AF patients compared to SR subjects (18.2 ± 8.7 versus 20.7 ± 5.3 %). Persistent AF patients had a higher degree of LAA and RAA fibrosis compared to paroxysmal AF patients (LAA 14.6 ± 8.7 versus 8.6 ± 4.7 %, p = 0.02, and RAA 28.2 ± 7.9 versus 18.2 ± 8.7 %, respectively, p = 0.04). The left atrial end diastolic volume index was higher in persistent AF patients compared to SR controls (38.3 ± 16.4 and 28 ± 11 ml/m(2), respectively, p = 0.04). No correlation between atrial fibrosis and electrogram fractionation or voltage was found. Patients with structural heart disease undergoing cardiac surgery have more fibrosis in the RAA than in the LAA. Furthermore, RAA fibrosis is increased in persistent AF but not paroxysmal AF patients compared to control subjects. Electrogram fractionation and low voltage did not provide accurate identification of the fibrotic substrate.

  19. Percutaneous closure of a very large left atrial appendage using the Amplatzer amulet.

    Science.gov (United States)

    Freixa, Xavier; Kwai Chan, Jason Leung; Tzikas, Apostolos; Garceau, Patrick; Basmadjian, Arsène; Ibrahim, Réda

    2013-10-01

    Although percutaneous left atrial appendage (LAA) closure is becoming a common procedure worldwide, there are still some anatomic limitations. The size of the LAA is one of the current limitations as the most popular devices do not allow the closure of very large LAAs. The new Amplatzer Cardiac Plug 2, also called "Amulet," has been redesigned not only to improve delivery and safety but also to allow the closure of larger LAAs. The present report describes the successful closure of a very large LAA using the Amulet.

  20. Left atrial appendage closure: patient, device and post-procedure drug selection.

    Science.gov (United States)

    Tzikas, Apostolos; Bergmann, Martin W

    2016-05-17

    Left atrial appendage closure (LAAC), a device-based therapy for stroke prevention in patients with atrial fibrillation, is considered an alternative to oral anticoagulation therapy, particularly for patients at high risk of bleeding. Proof of concept has been demonstrated by the PROTECT AF and PREVAIL trials which evaluated the WATCHMAN device (Boston Scientific, Marlborough, MA, USA) versus warfarin, showing favourable outcome for the device group. The most commonly used devices for LAAC are the WATCHMAN and its successor, the WATCHMAN FLX (Boston Scientific) and the AMPLATZER Cardiac Plug and more recently the AMPLATZER Amulet device (both St. Jude Medical, St. Paul, MN, USA). The procedure is typically performed via a transseptal puncture under fluoroscopic and echocardiographic guidance. Technically, it is considered quite demanding due to the anatomic variability and fragility of the appendage. Careful material manipulation, adequate operator training, and good cardiac imaging and device sizing allow a safe, uneventful procedure. Post-procedure antithrombotic drug selection is based on the patient's history, indication and quality of LAAC.

  1. Procedural success and intra-hospital outcome related to left atrial appendage morphology in patients that receive an interventional left atrial appendage closure.

    Science.gov (United States)

    Fastner, Christian; Behnes, Michael; Sartorius, Benjamin; Wenke, Annika; El-Battrawy, Ibrahim; Ansari, Uzair; Gill, Ishar-Singh; Borggrefe, Martin; Akin, Ibrahim

    2017-08-01

    The interventional left atrial appendage (LAA) closure represents an emerging alternative to oral anticoagulation for stroke prevention in certain atrial fibrillation patients. Preliminary results have suggested high procedural success rates and fewer peri-interventional complications; however, there persists an insufficient understanding of the role of many underlying confounding variables (e.g., anatomical characteristics). It was investigated whether varying LAA morphologies influence procedural success as well as in-hospital outcome. Sixty-seven patients ineligible for long-term oral anticoagulation were included in this single-center, prospective, observational registry spanning from the years 2014 to 2016. Interventions were performed with the Watchman occluder (Boston Scientific, Natick, MA) or the Amplatzer Amulet (St. Jude Medical, St. Paul, MN), at the operator's discretion. Results derived from the data describing procedural success, fluoroscopy, and peri-interventional safety events were classified according to the presenting LAA morphology (cauliflower, cactus, windsock, and chicken wing). Rates of successful implantation were high across all groups (≥98%; P = 0.326). Surrogate parameters underlining procedural complexity like median total duration (P = 0.415), median fluoroscopy time (P = 0.459), median dose area product (P = 0.698), and the median amount of contrast agent (P = 0.076) demonstrated similar results across all groups. Likewise, the periprocedural complication rate was not significantly different and was mainly restricted to minor bleeding events. Irrespective of the varying morphological presentation of the LAA, the procedural success rates, interventional characteristics, and safety events did not significantly differ among patients receiving an interventional LAA closure. © 2017 Wiley Periodicals, Inc.

  2. Early results of first versus second generation Amplatzer occluders for left atrial appendage closure in patients with atrial fibrillation.

    Science.gov (United States)

    Gloekler, Steffen; Shakir, Samera; Doblies, Janosch; Khattab, Ahmed A; Praz, Fabien; Guerios, Ênio; Koermendy, Dezsoe; Stortecky, Stefan; Pilgrim, Thomas; Buellesfeld, Lutz; Wenaweser, Peter; Windecker, Stephan; Moschovitis, Aris; Jaguszewski, Milosz; Landmesser, Ulf; Nietlispach, Fabian; Meier, Bernhard

    2015-08-01

    Transcatheter left atrial appendage (LAA) occlusion has been proven to be an effective treatment for stroke prophylaxis in patients with atrial fibrillation. For this purpose, the Amplatzer cardiac plug (ACP) was introduced. Its second generation, the Amulet, was developed for easier delivery, better coverage, and reduction of complications. To investigate the safety and efficacy of first generation versus second generation Amplatzer occluders for LAA occlusion. Retrospective analysis of prospectively collected data from the LAA occlusion registries of the Bern and Zurich university hospitals. Comparison of the last consecutive 50 ACP cases versus the first consecutive 50 Amulet cases in patients with non-valvular atrial fibrillation. For safety, a periprocedural combined endpoint, which is composed of death, stroke, cardiac tamponade, and bailout by surgery was predefined. For efficacy, the endpoint was procedural success. There were no differences between the two groups in baseline characteristics. The percentage of associated interventions during LAA occlusion was high in (78% with ACP vs. 70% with Amulet p = ns). Procedural success was similar in both groups (98 vs. 94%, p = 0.61). The combined safety endpoint for severe adverse events was reached by a similar rate of patients in both groups (6 vs. 8%, p = 0.7). Overall complication rate was insignificantly higher in the ACP group, which was mainly driven by clinically irrelevant pericardial effusions (24 vs. 14%, p = 0.31). Death, stroke, or tamponade were similar between the groups (0 vs. 2%, 0 vs. 0%, or 6 vs. 6%, p = ns). Transcatheter LAA occlusion for stroke prophylaxis in patients with atrial fibrillation can be performed with similarly high success rates with first and second generations of Amplatzer occluders. According to this early experience, the Amulet has failed to improve results of LAA occlusion. The risk for major procedural adverse events is acceptable but has to be taken into account when

  3. Cardiac procedures to prevent stroke: patent foramen ovale closure/left atrial appendage occlusion.

    Science.gov (United States)

    Freixa, Xavier; Arzamendi, Dabit; Tzikas, Apostolos; Noble, Stephane; Basmadjian, Arsene; Garceau, Patrick; Ibrahim, Réda

    2014-01-01

    Stroke is a major contributor to population morbidity and mortality. Cardiac thromboembolic sources are an important potential cause of stroke. Left atrial appendage (LAA) thromboembolism in association with atrial fibrillation is a major contributor to stroke occurrence, particularly in elderly individuals. Patent foramen ovale (PFO) acts as a potential conduit from the right-sided circulation to the brain, and has been suggested to be an important factor in cryptogenic stroke in the young patients. Advances in interventional cardiology have made it possible to deal with these potential stroke sources (LAA and PFO), but the available methods have intrinsic limitations that must be recognized. Furthermore, the potential value of LAA and PFO closure depends on our ability to identify when the target structure is importantly involved in stroke risk; this is particularly challenging for PFO. This article addresses the clinical use of PFO and LAA closure in stroke prevention. We discuss technical aspects of closure devices and methods, questions of patient selection, and clinical trials evidence. We conclude that for PFO closure, the clinical trials evidence is thus far negative in the broad cryptogenic stroke population, but closure might nevertheless be indicated for selected high-risk patients. LAA closure has an acceptable balance between safety and efficacy for atrial fibrillation patients with high stroke risk and important contraindications to oral anticoagulation. Much more work needs to be done to optimize the devices and techniques, and better define patient selection for these potentially valuable procedures.

  4. Left Atrial Appendage Isolation in Patients With Longstanding Persistent AF Undergoing Catheter Ablation: BELIEF Trial.

    Science.gov (United States)

    Di Biase, Luigi; Burkhardt, J David; Mohanty, Prasant; Mohanty, Sanghamitra; Sanchez, Javier E; Trivedi, Chintan; Güneş, Mahmut; Gökoğlan, Yalçın; Gianni, Carola; Horton, Rodney P; Themistoclakis, Sakis; Gallinghouse, G Joseph; Bailey, Shane; Zagrodzky, Jason D; Hongo, Richard H; Beheiry, Salwa; Santangeli, Pasquale; Casella, Michela; Dello Russo, Antonio; Al-Ahmad, Amin; Hranitzky, Patrick; Lakkireddy, Dhanunjaya; Tondo, Claudio; Natale, Andrea

    2016-11-01

    Longstanding persistent (LSP) atrial fibrillation (AF) is the most challenging type of AF. In addition to pulmonary vein isolation, substrate modification and triggers ablation have been reported to improve freedom from AF in patients with LSPAF. This study sought to assess whether the empirical electrical isolation of the left atrial appendage (LAA) could improve success at follow-up. This was an open-label, randomized study assessing the effectiveness of empirical electrical left atrial appendage isolation for the treatment of LSPAF. Patients were randomly assigned to undergo empirical electrical left atrial appendage isolation along with extensive ablation (group 1; n = 85) or extensive ablation alone (group 2; n = 88). Recurrence of atrial arrhythmias was the primary endpoint. Secondary endpoints included cardiac-related hospitalization, all-cause mortality, and stroke at follow-up. Major clinical characteristics were not different between the 2 groups. At 12-month follow-up, 48 (56%) patients in group 1 and 25 (28%) in group 2 were recurrence free after a single procedure (unadjusted hazard ratio [HR] for recurrence with standard ablation: 1.92; 95% confidence interval [CI]: 1.3 to 2.9; log-rank p = 0.001). After adjusting for age, sex, and left atrial size, standard ablation was predictive of recurrence (HR: 2.22; 95% CI: 1.29 to 3.81; p = 0.004). During repeat procedures, empirical electrical left atrial appendage isolation was performed in all patients. After an average of 1.3 procedures, cumulative success at 24-month follow-up was reported in 65 (76%) in group 1 and in 49 (56%) in group 2 (unadjusted HR: 2.24; 95% CI: 1.3 to 3.8; log-rank p = 0.003). This randomized study showed that both after a single procedure and after redo procedures in patients with LSPAF, empirical electrical isolation of the LAA improved long-term freedom from atrial arrhythmias without increasing complications. (Effect of Empirical Left Atrial Appendage Isolation on Long

  5. Endoscopic Ultrasound for the Detection of Left Atrial Appendage Thrombus: A Useful Technique in Patients with Transesophageal Echocardiography Contraindication

    Science.gov (United States)

    Jurado-Román, Alfonso; López-Viedma, Bartolomé; Piqueras-Flores, Jesús; López-Lluva, María T.

    2016-01-01

    Endoscopic ultrasound is a diagnostic and therapeutic technique used in specialized centers for patients that have undergone digestive procedures. This technique enables highly precise real-time imaging of the digestive tract wall and surrounding organs. Endoscopic ultrasound is also useful in patients with cardiovascular diseases such as atrial fibrillation. In patients with contraindication for transesophageal echocardiography due to high risk of esophageal bleeding or complications that may require immediate intervention, endoscopic ultrasound may be a safer option for visualizing atrial chambers to rule out the presence of left atrial appendage thrombi before cardioversion. PMID:27642527

  6. The chicken-wing morphology: an anatomical challenge for left atrial appendage occlusion.

    Science.gov (United States)

    Freixa, Xavier; Tzikas, Apostolos; Basmadjian, Arsène; Garceau, Patrick; Ibrahim, Rèda

    2013-10-01

    To describe the particular assessment and closure strategy that was followed in patients with left atrial appendages (LAA) with an early and severe bend. The presence of a chicken-wing morphology with an early and severe bend constitutes one of the most difficult anatomical settings for transcatheter LAA occlusion. Between November 2009 and December 2012, patients who presented chicken-wing LAA with an early (Amulet (n = 3). Successful occlusion was achieved in all patients. None of them presented any procedural complication. Follow-up transesophageal echocardiography at 3 months showed successful LAA sealing in all patients and no device embolization or thrombosis. According to our results, the pre-specified closing implantation technique for chicken-wing LAAs with an early and severe bend might be a valid strategy for this challenging anatomical setting. Further cases will be necessary to confirm the results. © 2013, Wiley Periodicals, Inc.

  7. Left Atrial Appendage Closure Guided by Integrated Echocardiography and Fluoroscopy Imaging Reduces Radiation Exposure.

    Directory of Open Access Journals (Sweden)

    Christiane Jungen

    Full Text Available To investigate whether percutaneous left atrial appendage (LAA closure guided by automated real-time integration of 2D-/3D-transesophageal echocardiography (TEE and fluoroscopy imaging results in decreased radiation exposure.In this open-label single-center study LAA closure (AmplatzerTM Cardiac Plug was performed in 34 consecutive patients (8 women; 73.1±8.5 years with (n = 17, EN+ or without (n = 17, EN- integrated echocardiography/fluoroscopy imaging guidance (EchoNavigator® [EN]; Philips Healthcare. There were no significant differences in baseline characteristics between both groups. Successful LAA closure was documented in all patients. Radiation dose was reduced in the EN+ group about 52% (EN+: 48.5±30.7 vs. EN-: 93.9±64.4 Gy/cm2; p = 0.01. Corresponding to the radiation dose fluoroscopy time was reduced (EN+: 16.7±7 vs. EN-: 24.0±11.4 min; p = 0.035. These advantages were not at the cost of increased procedure time (89.6±28.8 vs. 90.1±30.2 min; p = 0.96 or periprocedural complications. Contrast media amount was comparable between both groups (172.3±92.7 vs. 197.5±127.8 ml; p = 0.53. During short-term follow-up of at least 3 months (mean: 8.1±5.9 months no device-related events occurred.Automated real-time integration of echocardiography and fluoroscopy can be incorporated into procedural work-flow of percutaneous left atrial appendage closure without prolonging procedure time. This approach results in a relevant reduction of radiation exposure.ClinicalTrials.gov NCT01262508.

  8. Left Atrial Appendage Closure Guided by 3D Printed Cardiac Reconstruction: Emerging Directions and Future Trends.

    Science.gov (United States)

    Pellegrino, Pier Luigi; Fassini, Gaetano; DI Biase, Matteo; Tondo, Claudio

    2016-06-01

    Percutaneous left atrial appendage (LAA) occlusion has emerged as an alternative therapeutic approach to medical therapy for stroke prevention in patients with atrial fibrillation. 3D printing is a novel technology able to create a patient specific model of any given anatomical portion of the heart. Herein we report the first 2 cases of LAA occlusion procedure with 2 different systems, the Wave Crest device (Coherex Medical, Inc., USA) and the Amplatzer Amulet device (St. Jude Medical, St. Paul, MN, USA), in which a 3D printed LAA model (Care Tronik, Prato, Italy) was used in a rehearse phase. Both patients had history of paroxysmal AF and previous transient ischemic attack (TIA) occurred during oral anticoagulation with correct INR. In the first patient the occlusive device was positioned within the LAA after a rehearse occlusion using the 3D printed LAA plus a 27 mm Coherex Wavecrest device, demonstrating a good compression and sealing, particularly considering a proximal lobe of the appendage. In the second patient an attempt with the 27 mm Amulet device delivered within the 3D printed LAA, based on angiography and transesophageal echocardiographic (TEE), revealed insufficient covering of the proximal part of LAA vestibule; the device was released only after a second test with the 31 mm Amulet demonstrating a good sealing. These 2 cases demonstrated that 3D model could help in finding the correct position within LAA, sizing the device and guiding the choice of the closure device despite the measurements provided by angiography and TEE. © 2016 Wiley Periodicals, Inc.

  9. Left atrial appendage closure for prevention of death, stroke, and bleeding in patients with nonvalvular atrial fibrillation.

    Science.gov (United States)

    Gloekler, Steffen; Saw, Jacqueline; Koskinas, Konstantinos C; Kleinecke, Caroline; Jung, Werner; Nietlispach, Fabian; Meier, Bernhard

    2017-08-26

    Nonvalvular atrial fibrillation (AF) is the most frequent arrhythmia with a prevalence of 1%-2% in the general population. Its prevalence increases with age and its diagnosis benefits of improvement and simplification of technologies for its detection. Today, AF affects approximately 7% of individuals age>65years and 15%-20% of octogenarians. Due to stasis and activation of coagulation in a fibrillating atrium, patients are at increased risk of thromboembolism, in particular ischemic stroke, with an overall stroke risk of 5% per year. Since the left atrium itself is round and smooth-walled, thrombi typically do not form there, but almost exclusively in the left atrial appendage (LAA), a blind sac-like heterogeneous structure trabeculated by pectinate muscles. In the past five decades, oral anticoagulation (OAC) with vitamin K antagonists (VKA) has been the state-of-the art treatment to prevent stroke and systemic embolism from thrombi in AF. In the last decade, nonvitamin K dependant oral anticoagulants (NOAC) have been shown to be overall superior to VKA with respect to efficacy and safety in large trials and registries. Given the safety issues of indefinite OAC with either VKA or NOAC, it is plausible to consider left atrial appendage closure (LAAC) as an alternative strategy for prevention of all three catastrophes for patients with AF on anticoagulation: death, stroke or other systemic embolization, and bleeding. In the past years, LAAC has been compared to VKA in prospective randomized trials, yielding superior results regarding efficacy and non-inferiority regarding safety in the mid-term. Today, the decision to provide the most appropriate treatment for a patient with AF (OAC, NOAC, or LAAC) is complex and needs to be individualized. This review provides a comprehensive update on the current state of LAAC in the field of prevention of death, stroke and bleedings in patients suffering from nonvalvular AF. We describe the pathophysiology of the LAA with regard

  10. RELATIONSHIP OF LEFT VENTRICULAR SIZE TO LEFT ATRIAL AND LEFT ATRIAL APPENDAGE SIZE IN SINUS RHYTHM PATIENTS WITH DILATED CARDIOMYOPATHY

    Science.gov (United States)

    Bakalli, Aurora; Georgievska-Ismail, Ljubica; Musliu, Nebi; Koçinaj, Dardan; Gashi, Zaim; Zeqiri, Nexhmi

    2012-01-01

    Introduction: Thromboembolic events are a frequent cause of mortality in patients with congestive heart failure. The aim of or study was to evaluate the relationship of left ventricular end diastolic diameter (LVEDD) to left atrial (LA) size and left atrial appendage (LAA) size in patients with dilated cardiomyopathy in sinus rhythm, as well as to determine the prevalence of thrombi in LV and LA /LAA. Methods: This was a prospective cross-sectional study, conducted from December 2009 until December 2011. The study included 95 patients with dilated cardiomyopathy in sinus rhythm. Patients with swallowing problems, acute myocardial infarction, atrial fibrillation/flatter, severe systolic dysfunction, and/or patients who were taking oral anticoagulation therapy were excluded. Results: Mean patient age was 58.6 ± 12.2 years and 68.4% were men. Mean LVEDD of our population was 66.5 ± 6.5 mm, while mean LA atrium, LA volume and LAA maximal area were 46 ± 5.1 mm, 87.2 ± 38.7 cm3 and 4.7 ± 1.2 cm2, respectively. LA diameter (p<0.001) and LAA maximal area (p=0.01) showed to be independent predictors of LV size. LV thrombus was detected in 13 (13.7%) patients, while LAA thrombus in 46 (48.4%) patients of our study population. Conclusions: In conclusion, dilated LV size is associated with enlarged LA and LAA size. On the other hand, dilation of LV, LA and LAA is related to high prevalence of left chamber cardiac thrombi. PMID:23322961

  11. Percutaneous methods of left atrial appendage exclusion: an alternative to the internist.

    Science.gov (United States)

    Le, Duong L; Khodjaev, Soidjon D; Morelli, Remo L

    2014-01-01

    Thromboembolic stroke from the left atrial appendage (LAA) is the most feared complication in patients with atrial fibrillation (AF). The cornerstone for the management of chronic non-valvular AF is stroke reduction with oral anticoagulation (OAC). However, poor compliance, maintaining a narrow therapeutic window, and major side effects such as bleeding have severely limited their use, which creates a therapeutic dilemma. As much as 20% of AF patients are not receiving OAC due to contraindications and less than half of AF patients are not on OAC due to reluctance of the prescribing physician and/or patient non-compliance. Fortunately, over the past decade, there have been great interests in providing an alternative strategy unbeknownst to the practicing internist. The introduction of percutaneous approaches for LAA occlusion has added a different dimension to the management of chronic AF in patients with OAC intolerance. Occlusion devices such as the Amplatzer Cardiac Plug and WATCHMAN device are currently being investigated for stroke prophylaxis. More recently, the LARIAT device may provide an alternative means for potential stroke prophylaxis without the need for short-term post-procedural OAC. We aim to review the current literature and bring attention to an alternative strategy for high-risk AF patients intolerant to OAC.

  12. Velocity encoded cardiovascular magnetic resonance to assess left atrial appendage emptying

    Directory of Open Access Journals (Sweden)

    Muellerleile Kai

    2012-06-01

    Full Text Available Abstract Background The presence of impaired left atrial appendage (LAA function identifies patients who are prone to thrombus formation in the LAA and therefore being at high risk for subsequent cardioembolic stroke. LAA function is typically assessed by measurements of LAA emptying velocities using transesophageal echocardiography (TEE in clinical routine. This study aimed at evaluating the feasibility of assessing LAA emptying by velocity encoded (VENC cardiovascular magnetic resonance (CMR. Methods This study included 30 patients with sinus rhythm (n = 18 or atrial fibrillation (n = 12. VENC-CMR velocity measurements were performed perpendicular to the orifice of the LAA. Peak velocities were measured of passive diastolic LAA emptying (e-wave in all patients. Peak velocities of active, late-diastolic LAA emptying (a-wave were assessed in patients with sinus rhythm. Correlation and agreement was analyzed between VENC-CMR and TEE measurements of e- and a-wave peak velocities. Results A significant correlation and good agreement was found between VENC-CMR and TEE measurements of maximal e-wave velocities (r = 0.61, P  Conclusions The assessment of active and passive LAA emptying by VENC-CMR is feasible. Further evaluation is required of potential future clinical applications such as risk stratification for cardioembolic stroke.

  13. Percutaneous left atrial appendage closure: procedural techniques and outcomes.

    Science.gov (United States)

    Saw, Jacqueline; Lempereur, Mathieu

    2014-11-01

    Percutaneous left atrial appendage closure technology for stroke prevention in patients with atrial fibrillation has significantly advanced in the past 2 decades. Several devices are under clinical investigation, and a few have already received Conformité Européene (CE)-mark approval and are available in many countries. The WATCHMAN device (Boston Scientific, Natick, Massachusetts) has the most supportive data and is under evaluation by the U.S. Food and Drug Administration for warfarin-eligible patients. The Amplatzer Cardiac Plug (St. Jude Medical, Plymouth, Minnesota) has a large real-world experience over the past 5 years, and a randomized trial comparing Amplatzer Cardiac Plug with the WATCHMAN device is anticipated in the near future. The Lariat procedure (SentreHEART Inc., Redwood City, California) has also gained interest lately, but early studies were concerning for high rates of serious pericardial effusion and major bleeding. The current real-world experience predominantly involves patients who are not long-term anticoagulation candidates or who are perceived to have high bleeding risks. This pattern of practice is expected to change when the U.S. Food and Drug Administration approves the WATCHMAN device for warfarin-eligible patients. This paper reviews in depth the procedural techniques, safety, and outcomes of the current leading devices. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  14. Twelve-month follow-up of left atrial appendage occlusion with Amplatzer Amulet.

    Science.gov (United States)

    Kleinecke, Caroline; Park, Jai-Wun; Gödde, Martin; Zintl, Konstantin; Schnupp, Steffen; Brachmann, Johannes

    2017-01-01

    The Amplatzer Amulet (St. Jude Medical, Minneapolis, MN, USA) is a second gen-eration Amplatzer device for left atrial appendage (LAA) occlusion (LAAO) for stroke prophylaxis in patients with atrial fibrillation. This research sought to assess the clinical performance of the Amplatzer Amulet device and in follow up for 12 months. In this single-center registry patients with atrial fibrillation and contraindication to oral anticoagulation underwent LAAO with the Amplatzer Amulet device. Follow-up was performed before discharge, by transesophageal echocardiography (TEE) after 6 weeks and telephone interview after 3, 6 and 12 months. Between October 2014 and August 2015 50 patients (76.1 ± 8.3 years; 30 male) were en-rolled. Procedural success was achieved in 49 (98%) patients. Major periprocedural adverse events were observed in 4 (8%) of patients: 1 device embolization, 2 pericardial effusions requiring pericardiocente-sis and 1 prolonged hospital stay due to retropharyngeal hematoma from the TEE probe. Follow-up TEE was available in 38 of 50 patients showing complete LAA sealing in all. 2 device-related thrombi were also documented. At 12-month follow-up 7 patients had died unrelated to the device. Ischemic stroke occurred in 3 patients. According to neurological examination two were classified as microangiopathic and not cardio-embolic. The other one could not be classified. Bleeding complications (5 minor, 3 major) were documented in 8 patients. Although minimizing procedure-related complications remains challenging, LAAO with the Amplatzer Amulet device showed high procedural success and excellent LAA sealing. (Cardiol J 2017; 24, 2: 131-138).

  15. [GISE/AIAC position paper on percutaneous left atrial appendage occlusion in patients with nonvalvular atrial fibrillation: recommendations for patient selection, facilities, competences, organizing and training requirements].

    Science.gov (United States)

    Berti, Sergio; Themistoclakis, Sakis; Santoro, Gennaro; De Ponti, Roberto; Danna, Paolo; Zecchin, Massimo; Bedogni, Francesco; Padeletti, Luigi

    2014-09-01

    Thromboembolism from the left atrial appendage is the most feared complication in patients with atrial fibrillation (AF). The cornerstone for the management of chronic nonvalvular AF is stroke reduction with oral anticoagulation (OAC). However, poor compliance, maintaining a narrow therapeutic window, and major side effects such as bleeding have severely limited its use, creating a therapeutic dilemma. About 20% of AF patients do not receive OAC due to contraindications and less than half of AF patients are not on OAC due to reluctance of the prescribing physician and/or patient non-compliance. Fortunately, over the past decade, the introduction of percutaneous approaches for left atrial appendage occlusion has offered a viable alternative to the management of nonvalvular AF in patients with OAC contraindication. Occlusion devices such as the Amplatzer Cardiac Plug and Watch man device have shown their noninferiority to OAC for stroke prophylaxis with less bleeding complications, while more recently some new devices have been introduced. The aim of this position paper is to review the most relevant clinical aspects of left atrial appendage occlusion from patient selection to periprocedural and follow-up management. In addition, the importance of a medical team and an organizational environment adequate to optimize all the steps of this procedure is discussed.

  16. Percutaneous left atrial appendage occlusion - treatment outcomes and 6 months of follow-up - a single-center experience.

    Science.gov (United States)

    Karczewski, Michał; Woźniak, Sebastian; Skowronek, Radomir; Burysz, Marian; Fischer, Marcin; Anisimowicz, Lech; Demkow, Marcin; Konka, Marek; Ogorzeja, Wojciech

    2016-06-01

    To present the results of treatment and evaluate 6 months of follow-up in a group of patients with non-valvular atrial fibrillation, who underwent the procedure of percutaneous left atrial appendage occlusion (PLAAO). Percutaneous left atrial appendage occlusion was performed in 34 patients with non-valvular atrial fibrillation and contraindications for oral anticoagulation therapy. The risk of thromboembolic and bleeding complications was determined based on the CHA2DS2VASc and HAS-BLED scales. The Amplatzer Amulet system from St. Jude Medical was used. On the first postoperative day, all patients were started on double antiplatelet therapy with 75 mg/day of acetylsalicylic acid (ASA) and 75 mg/day of clopidogrel (CLO). On the 30(th) postoperative day, the efficacy of the antiplatelet therapy was assessed with impedance aggregometry using a Multiplate analyzer (Roche). Echocardiographic examinations were performed intraoperatively and on the first postoperative day; subsequently, follow-up examinations were conducted 1 and 6 months after the implantation. In all patients, proper occluder position was observed throughout the follow-up. No leakage or thrombi around the implants were found. No strokes or bleeding complications associated with the antiplatelet therapy were observed. Multiplate assessment of platelet activity was conducted in 20 out of 34 patients. The efficacy of ASA treatment was demonstrated in all patients; no response to clopidogrel treatment was observed in 5 out of 20 patients. One patient suffered from cardiac tamponade, which required the performance of full sternotomy. Local complications (hematomas of the inguinal region) were observed in 3 patients. One of the patients died for reasons unrelated to the procedure. Percutaneous left atrial appendage occlusion is an effective procedure in patients with non-valvular atrial fibrillation and contraindications for chronic anticoagulation therapy. Further observation is necessary to evaluate the

  17. Left Atrial Appendage Closure Device With Delivery System: A Health Technology Assessment

    Science.gov (United States)

    Nevis, Immaculate; Falk, Lindsey; Wells, David; Higgins, Caroline

    2017-01-01

    Background Atrial fibrillation is a common cardiac arrhythmia, and 15% to 20% of those who have experienced stroke have atrial fibrillation. Treatment options to prevent stroke in people with atrial fibrillation include pharmacological agents such as novel oral anticoagulants or nonpharmacological devices such as the left atrial appendage closure device with delivery system (LAAC device). The objectives of this health technology assessment were to assess the clinical effectiveness and cost-effectiveness of the LAAC device versus novel oral anticoagulants in patients without contraindications to oral anticoagulants and versus antiplatelet agents in patients with contraindications to oral anticoagulants. Methods We performed a systematic review and network meta-analysis. We also conducted an economic literature review, economic evaluation, and budget impact analysis to assess the cost-effectiveness and budget impact of the LAAC device compared with novel oral anticoagulants and oral antiplatelet agents (e.g., aspirin). We also spoke with patients to better understand their preferences, perspectives, and values. Results Seven randomized controlled studies met the inclusion criteria for indirect comparison. Five studies assessed the effectiveness of novel oral anticoagulants versus warfarin, and two studies compared the LAAC device with warfarin. No studies were identified that compared the LAAC device with aspirin in patients in whom oral anticoagulants were contraindicated. Using the random effects model, we found that the LAAC device was comparable to novel oral anticoagulants in reducing stroke (odds ratio [OR] 0.85; credible interval [Cr.I] 0.63–1.05). Similarly, the reduction in the risk of all-cause mortality was comparable between the LAAC device and novel oral anticoagulants (OR 0.71; Cr.I 0.49–1.22). The LAAC device was found to be superior to novel oral anticoagulants in preventing hemorrhagic stroke (OR 0.45; Cr.I 0.29–0.79), whereas novel oral

  18. Single trans-septal access technique for left atrial intracardiac echocardiography to guide left atrial appendage closure.

    Science.gov (United States)

    Aguirre, Daniel; Pincetti, Christian; Perez, Luis; Deck, Carlos; Alfaro, Mario; Vergara, Maria Jesus; Maluenda, Gabriel

    2017-08-24

    This registry aimed to describe the safety and feasibility of a single trans-septal (TS) access technique for left intracardiac echocardiography (ICE) guidance of left-atrial appendage (LAA) closure procedure. LAA closure is currently accepted as an alternative to oral anticoagulation (OAC) in patients with non-valvular atrial fibrillation (NVAF) who are at high-risk for bleeding. Currently, LAA closure procedure is typically performed under trans-esophageal echocardiogram (TEE) guidance. Although, ICE has the advantage of not requiring profound sedation/anesthesia, ICE-LAA imaging quality is often limited from the right atrium requiring double TS access. Twenty-two patients with NVAF underwent LAA closure using the Amplatzer Amulet™ device (St Jude Medical) under ICE guidance from the left atrium. The ICE AcuNav catheter (Biosense Webster) and the Amulet delivery sheath were advanced into the LA through single TS puncture technique. The population was predominately male (59.1%) with a mean age of 74 ± 9.3 years, at high-risk for stroke (mean CHADS2 score of 3.8 ± 1.1) and bleeding (mean HAS BLED score of 3.5 ± 1.3). The Amplatzer Amulet(TM) device was successfully implanted in all patients. No procedural related complications including device embolization were noted. No major cardiovascular events occurred and all patients were discharged alive. At 30-day follow-up all patients remained alive, free of ischemic stroke and with no residual leak or device thrombus on TEE. This initial experience suggests that LAA occlusion with the Amplatzer Amulet device using ICE guidance from the left atrium via a single trans-septal technique is feasible and safe. © 2017 Wiley Periodicals, Inc.

  19. The Amplatzer™ Cardiac Plug 2 for left atrial appendage occlusion: novel features and first-in-man experience.

    Science.gov (United States)

    Freixa, Xavier; Chan, Jason L K; Tzikas, Apostolos; Garceau, Patrick; Basmadjian, Arsène; Ibrahim, Réda

    2013-01-22

    Percutaneous left atrial appendage (LAA) closure is becoming a frequently performed procedure for patients with atrial fibrillation and high haemorrhagic risk. The Amplatzer™ Cardiac Plug (ACP) is one of the most commonly used devices for this purpose. Despite high success rate and low procedure risk associated with the ACP, a second generation of the device is now available. The new ACP has been designed to facilitate the implantation process, improve sealing performance and further reduce the risk of complications. The present report focuses on the novel features of the second generation of the Amplatzer™ Cardiac Plug (ACP 2 or Amulet™) and describes the first-in-man experience.

  20. A comparative study of different imaging modalities for successful percutaneous left atrial appendage closure.

    Science.gov (United States)

    Chow, Danny Hf; Bieliauskas, Gintautas; Sawaya, Fadi J; Millan-Iturbe, Oscar; Kofoed, Klaus F; Søndergaard, Lars; De Backer, Ole

    2017-01-01

    Accurate sizing of the left atrial appendage (LAA) is essential when performing percutaneous LAA closure. This study aimed to compare different LAA imaging modalities and sizing methods in order to obtain successful LAA closure. Percutaneous LAA closure is an increasingly used treatment strategy to prevent stroke in patients with atrial fibrillation. LAA sizing has typically been done by 2D-transoesophageal echocardiography (TEE). Patients who had a preprocedural TEE and preprocedural and postprocedural multislice CT (MSCT) were identified. Preprocedural measurements of LAA ostia and landing zones by 2D-TEE, MSCT and angiography were collected and analysed for those patients with successful LAA closure - i.e. with no contrast leakage at 3-month follow-up MSCT. The study population (n=67) had a mean CHA2DS2-VASc score of 3.0 and HAS-BLED score of 2.7. Fifty-eight patients (87%) were identified to have successful LAA closure. Based on MSCT, 48 LAA sizings (83%) resulted in a correct LAA closure device size selection, whereas with 2D-TEE sizing, only 33 measurements (57%) would have resulted in a correct device size selection (pAmulet, WatchmanFLX), whereas the maximal diameter was the best parameter for the ‘open-end’ Watchman device. Preprocedural MSCT-based LAA closure device size selection proves to be a more accurate method than conventional 2D-TEE-based sizing. Depending on the LAA closure device design, perimeter-derived mean diameter or maximal diameter could be the better sizing method.

  1. Cardiac CT angiography for device surveillance after endovascular left atrial appendage closure.

    Science.gov (United States)

    Saw, Jacqueline; Fahmy, Peter; DeJong, Peggy; Lempereur, Mathieu; Spencer, Ryan; Tsang, Michael; Gin, Kenneth; Jue, John; Mayo, John; McLaughlin, Patrick; Nicolaou, Savvas

    2015-11-01

    Left atrial appendage (LAA) device imaging after endovascular closure is important to assess for device thrombus, residual leak, positioning, surrounding structures, and pericardial effusion. Cardiac CT angiography (CCTA) is well suited to assess these non-invasively. We report our consecutive series of non-valvular atrial fibrillation patients who underwent CCTA post-LAA closure with Amplatzer Cardiac Plug (ACP), Amulet (second generation ACP), or WATCHMAN devices. Patients underwent CCTA typically 1-6 months post-implantation. Prospective cardiac-gated CCTA was performed with Toshiba 320-detector or Siemens 2nd generation 128-slice dual-source scanners, and images interpreted with VitreaWorkstation™. GFR Amulet, 18 WATCHMAN). Average age was 75.5 ± 8.9 years, mean CHADS2 score 3.1 ± 1.3, and CHADS-VASc score 4.9 ± 1.6. All had contraindications to oral anticoagulation. Post-procedure, 41 (91.1%) were discharged on DAPT. There was one device embolization (ACP, successfully retrieved percutaneously) and one thrombus (WATCHMAN, resolved with 3 months of warfarin). There were two pericardial effusions, both pre-existing and not requiring intervention. Residual leak (patency) was seen in 28/44 (63.6%), and the mechanisms of leak were readily identified by CCTA (off-axis device, gaps at orifice, or fabric leak). Mean follow-up was 1.2 ± 1.1year, with no death, stroke, or systemic embolism. CCTA appears to be a feasible alternative to transoesophageal echocardiography for post-LAA device surveillance to evaluate for device thrombus, residual leak, embolization, position, and pericardial effusion. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  2. Far field R-wave sensing in Myotonic Dystrophy type 1: right atrial appendage versus Bachmann's bundle region lead placement.

    Science.gov (United States)

    Russo, Vincenzo; Nigro, Gerardo; Antonio Papa, Andrea; Rago, Anna; Di Meo, Federica; Cristiano, Anna; Molino, Antonio; Calabrò, Raffaele; Giovanna Russo, Maria; Politano, Luisa

    2014-10-01

    Aim of the present study was to investigate far field R-wave sensing (FFRS) timing and characteristics in 34 Myotonic Dystrophy type 1 (DM1) patients undergoing dual chamber pacemaker implantation, comparing Bachmann's bundle (BB) stimulation (16 patients) site with the conventional right atrial appendage (RAA) pacing site (18 patients). All measurements were done during sinus rhythm and in supine position, with unipolar (UP) and bipolar (BP) sensing configuration. The presence, amplitude threshold (FFRS trsh) and FFRS timing were determined. There were no differences between both atrial sites in the Pmin and Pmean values of sensed P-wave amplitudes, as well as between UP and BP sensing configurations. The FFRS trsh was lower at the BB region in comparison to the RAA site. The mean BP FFRS trsh was significantly lower than UP configuration in both atrial locations. There were no significant differences in atrial pacing threshold, sensing threshold and atrial lead impedances at the implant time and at FFRS measurements. Bachmann's bundle area is an optimal atrial lead position for signal sensing as well as conventional RAA, but it offers the advantage of reducing the oversensing of R-wave on the atrial lead, thus improving functioning of standard dual chamber pacemakers in DM1 patients.

  3. Predictors of Early (1-Week) Outcomes Following Left Atrial Appendage Closure With Amplatzer Devices.

    Science.gov (United States)

    Koskinas, Konstantinos C; Shakir, Samera; Fankhauser, Máté; Nietlispach, Fabian; Attinger-Toller, Adrian; Moschovitis, Aris; Wenaweser, Peter; Pilgrim, Thomas; Stortecky, Stefan; Praz, Fabien; Räber, Lorenz; Windecker, Stephan; Meier, Bernhard; Gloekler, Steffen

    2016-07-11

    The aim of this study was to assess predictors of adverse 1-week outcomes and determine the effect of left atrial appendage (LAA) morphology following LAA closure (LAAC) with Amplatzer devices. Percutaneous LAAC is a valuable treatment option for stroke prevention in patients with atrial fibrillation. Determinants of procedural safety events with Amplatzer occluders are not well established, and the possibly interrelating effect of LAA anatomy is unknown. Between 2009 and 2014, 500 consecutive patients with atrial fibrillation ineligible or at high risk for oral anticoagulation underwent LAAC using Amplatzer devices. Procedure- and device-related major adverse events (MAEs) were defined as the composite of death, stroke, major or life-threatening bleeding, serious pericardial effusion, device embolization, major access-site vascular complication, or need for cardiovascular surgery within 7 days following the intervention. Patients (mean age 73.9 ± 10.1 years) were treated with Amplatzer Cardiac Plug (n = 408 [82%]) or Amulet (n = 92 [18%]) devices. Early procedural success was 97.8%, and MAEs occurred in 29 patients (5.8%). Independent predictors of MAEs included device repositioning (odds ratio: 9.13; 95% confidence interval: 2.85 to 33.54; p < 0.001) and left ventricular ejection fraction <30% (odds ratio: 4.08; 95% confidence interval: 1.49 to 11.20; p = 0.006), with no effect of device type or size. Angiographic LAA morphology, characterized as cauliflower (33%), cactus (32%), windsock (20%), or chicken wing (15%), was not associated with procedural success (p = 0.51) or the occurrence of MAEs (p = 0.78). In this nonrandomized study, procedural success of LAAC using Amplatzer devices was high. MAEs within 7 days were predicted by patient- and procedure-related factors. Although LAA morphology displayed substantial heterogeneity, outcomes were comparable across the spectrum of LAA anatomies. Copyright © 2016 American College of Cardiology Foundation

  4. Early Canadian Multicenter Experience With WATCHMAN for Percutaneous Left Atrial Appendage Closure.

    Science.gov (United States)

    Saw, Jacqueline; Fahmy, Peter; Azzalini, Lorenzo; Marquis, Jean-Francois; Hibbert, Benjamin; Morillo, Carlos; Carrizo, Aldo; Ibrahim, Reda

    2017-04-01

    There are limited data with WATCHMAN (Boston Scientific Corporation, Natick, MA, USA) for left atrial appendage (LAA) closure in patients with nonvalvular atrial fibrillation (AF) and contraindications to anticoagulation. The purpose of this study was to evaluate the safety and efficacy of WATCHMAN in our early Canadian experience. We report our pooled consecutive series of patients who underwent WATCHMAN implantation at four major Canadian centers. Indications for LAA closure were CHADS2 ≥ 1 or CHA2 DS2 -VASc ≥ 2, and contraindication/intolerance to or failure on anticoagulation. Follow-up imaging was typically performed 1-6 months postprocedure. One hundred and six patients underwent LAA closure with WATCHMAN from May 2013 to October 2015. The mean age was 74.8 ± 7.7, mean CHADS2 score was 2.8 ± 1.2, CHA2 DS2 -VASc score was 4.3 ± 1.5, and HASBLED score was 3.2 ± 1.2. Permanent AF was present in 67.9% and paroxysmal AF in 32.1%. Indications for LAA closure were prior bleeding 89.6% (87 major bleeding and 8 minor bleeding), 9.4% were deemed high risk for bleeding, and 0.9% with recurrent strokes on warfarin. Procedural success was 97.2% (103 of 106), with one device embolization (snared percutaneously), one implant failure due to inadequate LAA depth, and one cardiac perforation requiring surgical repair before WATCHMAN implantation. The composite major safety event-rate was 1.9% (1 death and 1 device embolization). Mean hospital stay was 1.8 ± 4.7 days. Antithrombotic therapy postimplant included dual antiplatelet therapy in 76 of 103 (73.8%). Mean follow-up was 210 ± 182 days; there were two transient ischemic attacks, with estimated 66% reduction in thromboembolic events relative to CHADS2 predicted risk. In our early Canadian experience, WATCHMAN for LAA closure in patients contraindicated to anticoagulation appeared safe and effective. © 2017 Wiley Periodicals, Inc.

  5. Percutaneous left atrial appendage occlusion procedures in patients with heart failure.

    Science.gov (United States)

    Szymała, Magdalena; Streb, Witold; Mitręga, Katarzyna; Podolecki, Tomasz; Mencel, Grzegorz; Kukulski, Tomasz; Kalarus, Zbigniew

    2017-01-01

    Atrial fibrillation (AF) is the most common supraventricular tachyarrhythmia. Percutaneous left atrial appendage occlusion (LAAO) may be considered for stroke prophylaxis in patients with nonvalvular AF (NVAF), especially in contraindications for oral anticoagulants (OAC) or high risk of bleeding. The data about implantation, safety, efficacy, and follow-up are limited. Moreover, there are no studies on patients with NVAF and heart failure with severe left ventricular systolic dysfunction (left ventricular ejection fraction [LVEF] ≤ 35%). To assess the safety, efficacy, and mid-term outcomes of LAAO procedures with Amplatzer Cardiac Plug (ACP) and Amplatzer Amulet device in patients with NVAF and heart failure with LVEF ≤ 35% (group I) and to perform a comparative analysis of the patients who had LAAO with NVAF and LVEF > 35%. The analysis included 80 patients (group I: 19, group II: 61) with NVAF. The patients were enrolled for the study if they had: CHA2DS2VASc ≥ 2 and high risk of bleeding assessed in HAS-BLED (≥ 3) or less points in HAS-BLED but coexisting contraindications for OAC, or thromboembolic complications while using OAC. Time of follow-up was six months. In the studied population, the median CHA2DS2VASc score was 4 and the average HAS-BLED score was 3.2. Device implantation was successful in all patients from group I and in 59/61 patients from group II. The periprocedural clinical ef-ficacy (no thromboembolic complications) was 100% in group I and 98.4% in group II. Serious periprocedural complications (cardiac tamponade: 2.5%, device embolisation: 1.25%, unexplained death: 1.25%) occurred only in patients from group II (p = NS). The mid-term clinical efficacy was 100% in group I and 98.3% in group II (p = NS). During follow-up, one transient ischaemic attack and three deaths not related to the procedure occurred. Percutaneous LAAO is an effective and safe procedure in patients with NVAF and severe systolic heart failure. No significant

  6. Application of an Epicardial Left Atrial Appendage Occlusion Device by a Robotic-Assisted, Right Chest Approach.

    Science.gov (United States)

    Lewis, Clifton T P; Stephens, Richard L; Horst, Vernon D; Angelillo, Margaret; Tyndal, Charles M

    2016-05-01

    Closure of the left atrial appendage (LAA) has become a standard part of any mitral valve operation because it is thought to reduce the potential for late thrombus development and for embolic events. To date, surgeons performing robotic mitral valve operations have been limited to an endocardial approach to LAA closure. However, oversewing the orifice of the LAA is time consuming and lengthens the cross-clamp time, and failures to obtain permanent closure have been reported. We describe our technique for an epicardial approach that is safe and efficient and that gives a secure closure of the LAA.

  7. Left atrial appendage occlusion with Amplatzer Cardio Plug is an acceptable therapeutic option for prevention of stroke recurrence in patients with non-valvular atrial fibrillation and contraindication or failure of oral anticoagulation with acenocumarol

    OpenAIRE

    Hawkes, Maximiliano A; Lucía Pertierra; Federico Rodriguez-Lucci; Virginia A. Pujol-Lereis; Sebastián F. Ameriso

    2016-01-01

    ABSTRACT Left atrial appendage occlusion (LAAO) appears as a therapeutic option for some atrial fibrillation patients not suitable for oral anticoagulation because an increased hemorrhagic risk or recurrent ischemic events despite anticoagulant treatment. Methods Report of consecutive atrial fibrillation patients treated with LAAO with Amplatzer Cardio Plug because contraindication or failure of oral anticoagulation with acenocumarol. CHA2DS2VASC, HAS-BLED, NIHSS, mRS, procedural complicati...

  8. Left atrial appendage occlusion with Amplatzer Cardio Plug is an acceptable therapeutic option for prevention of stroke recurrence in patients with non-valvular atrial fibrillation and contraindication or failure of oral anticoagulation with acenocumarol

    OpenAIRE

    Hawkes,Maximiliano A; Lucía Pertierra; Federico Rodriguez-Lucci; Pujol-Lereis,Virginia A.; Ameriso,Sebastián F

    2016-01-01

    ABSTRACT Left atrial appendage occlusion (LAAO) appears as a therapeutic option for some atrial fibrillation patients not suitable for oral anticoagulation because an increased hemorrhagic risk or recurrent ischemic events despite anticoagulant treatment. Methods Report of consecutive atrial fibrillation patients treated with LAAO with Amplatzer Cardio Plug because contraindication or failure of oral anticoagulation with acenocumarol. CHA2DS2VASC, HAS-BLED, NIHSS, mRS, procedural complicati...

  9. Echocardiographic guidance and monitoring of left atrial appendage closure with AtriClip during open-chest cardiac surgery.

    Science.gov (United States)

    Contri, Rachele; Clivio, Sara; Torre, Tiziano; Cassina, Tiziano

    2017-09-12

    Left atrial appendage (LAA) closure prevents thromboembolic risk and avoids lifelong anticoagulation due to atrial fibrillation (AF). Nowadays, AtriClip, a modern epicardial device approved in June 2010, allows external and safe closure of LAA in patients undergoing cardiac surgery during other open-chest cardiac surgical procedures. Such a surgical approach and its epicardial deployment differentiates LAA closure with AtriClip from percutaneous closure techniques such as Watchman (Boston Scientific, Marlborough, MA, USA), Lariat (SentreHEART Inc., Redwood City, CA, USA), and Amplatzer Amulet (St. Jude Medical, St. Paul, MN, USA) device procedures. AtriClip positioning must consider perioperative transesophageal echocardiography (TEE) to confirm LAA anatomical features, to explore the links with neighboring structures, and finally to assess its successful closure. We report a sequence of images to document the role of intraoperative TEE during an elective aortic valve replacement and LAA external closure with AtriClip. © 2017, Wiley Periodicals, Inc.

  10. Effect of Metabolic Syndrome on Risk Stratification for Left Atrial or Left Atrial Appendage Thrombus Formation in Patients with Nonvalvular Atrial Fibrillation

    Science.gov (United States)

    Chen, Yu-Yang; Liu, Qi; Liu, Li; Shu, Xiao-Rong; Su, Zi-Zhuo; Zhang, Hai-Feng; Nie, Ru-Qiong; Wang, Jing-Feng; Xie, Shuang-Lun

    2016-01-01

    Background: Metabolic syndrome (MS) is a risk factor for stroke and thromboembolism event. Left atrial or LA appendage (LA/LAA) thrombus is a surrogate of potential stroke. The relationship between MS and atrial thrombus remains unclear. In this study, we sought to investigate the effect of MS on risk stratification of LA/LAA thrombus formation in patients with nonvalvular atrial fibrillation (NVAF). Methods: This cross-sectional study enrolled 294 consecutive NVAF patients without prior anticoagulant and lipid-lowering therapies. LA/LAA thrombus was determined by transesophageal echocardiography. Risk assessment of LA/LAA thrombus was performed using the CHADS2, CHA2DS2-VASc, MS, CHADS2-MS, and CHA2DS2-VASc-MS scores. Logistic regression analyses were performed to determine which factors were significantly related to LA/LAA thrombus. Odds ratio (OR) including 95% confidence interval was also calculated. The predictive powers of different scores for the risk of LA/LAA thrombus were represented by C-statistics and compared by receiver operating characteristic (ROC) analysis. Results: LA/LAA thrombi were identified in 56 patients (19.0%). Logistic analysis showed that MS was the strongest risk factor for LA/LAA thrombus in NVAF patients (OR = 14.698, P < 0.001). ROC curve analyses revealed that the C-statistics of CHADS2-MS and CHA2DS2-VASc-MS was significantly higher than those of CHADS2 and CHA2DS2-VASc scores (CHADS2-MS vs. CHADS2, 0.807 vs. 0.726, P = 0.0019). Furthermore, MS was helpful for identifying individuals with a high risk of LA/LAA thrombus in the population with a low risk of stroke (CHADS2 or CHA2DS2-VASc score = 0). Conclusions: MS is associated with LA/LAA thrombus risk in patients with NVAF. In addition to the CHADS2 and CHA2DS2-VASc scores, the CHADS2-MS and CHA2DS2-VASc-MS scores provide additional information on stroke risk assessment. PMID:27748329

  11. Comparing Measurements of CT Angiography, TEE, and Fluoroscopy of the Left Atrial Appendage for Percutaneous Closure.

    Science.gov (United States)

    Saw, Jacqueline; Fahmy, Peter; Spencer, Ryan; Prakash, Roshan; McLaughlin, Patrick; Nicolaou, Savvas; Tsang, Michael

    2016-04-01

    Left atrial appendage (LAA) closure requires accurate preprocedural measurements, and trans-esophageal echocardiography (TEE), cardiac computed tomography angiography (CCTA) and fluoroscopy can be utilized. However, correlations between these measurements remain inadequately assessed. Patients who underwent LAA closure at Vancouver General Hospital who had baseline LAA measurements by CCTA, TEE, and fluoroscopy were included in this analysis. CCTAs were performed with prospective-ECG-gating with Toshiba 320-detector or Siemens second generation 128-slice dual-source scanners, and images interpreted with VitreaWorkstation.™ LAA maximal dimensions were obtained for all patients at: (1) Amplatzer Cardiac Plug (ACP)/Amulet landing zone 10 mm within orifice, (2) WATCHMAN ostium, and (3) WATCHMAN depth measurements. Correlations and agreements were compared. We report 50 consecutive patients who underwent LAA closure (8 ACP, 10 Amulet, 32 WATCHMAN). Average age was 75.2 ± 8.7 years, mean CHADS2 score 3.0 ± 1.3, and CHA2 DS2 -VASc 4.7 ± 1.5. Procedural device implantation success was 100%. For ACP landing zone, mean maximal measurements were 24.1 ± 4.7 mm with CCTA, 22.3 ± 4.9 mm TEE, and 19.9 ± 5.6 mm fluoroscopy (P < 0.001); R value 0.81 fluoroscopy/CTA, 0.67 fluoroscopy/TEE, and 0.80 CTA/TEE. For WATCHMAN ostium, mean maximal measurements were 25.8 ± 4.7 mm CCTA (P < 0.001 vs. fluoroscopy, P = 0.16 vs. TEE), 25.1 ± 4.4 mm TEE (P = 0.016 vs. fluoroscopy), and 23.8 ± 4.9 mm fluoroscopy; R value 0.71 fluoroscopy/CTA, 0.65 fluoroscopy/TEE, and 0.74 CTA/TEE. Depth measurements were 34.3 ± 5.7 mm with CCTA, 31.1 ± 6.5 mm TEE, and 27.8 ± 7.1 mm fluoroscopy (all P < 0.01); and correlations with R value 0.28 fluoroscopy/CTA, 0.22 fluoroscopy/TEE, and 0.56 CTA/TEE. All 3 imaging modalities correlated with ACP landing zone and WATCHMAN ostium measurements, with CCTA providing the largest measurements, followed by TEE and fluoroscopy. © 2016 Wiley Periodicals, Inc.

  12. Potential uselessness and futility of left atrial appendage occlusion and patent foramen ovale closure in cardioembolic stroke.

    Science.gov (United States)

    Nicolosi, Gian L

    2017-02-16

    International guidelines indicate that interventional closure of left atrial appendage and patent foramen ovale may be considered in selected patients for stroke prevention. These procedures appear, however, from the published literature, at high risk of uselessness and futility in the single case, if not even capable to induce harm and adverse events. In fact, all reported systematic reviews and meta-analyses have not shown in a convincing manner the superiority of these procedures in stroke prevention, taking into account the occurrence of possible complications also, as compared with alternative medical treatment. On the basis of these considerations, it becomes very difficult to define always and unequivocally how adequate and complete was the information when given to each single candidate patient before the procedure by the Heart Team, the left atrial appendage occlusion Team or patent foramen ovale closure Team, potentially involved in conflict of interest. Before indicating these procedures, a complete diagnostic work-up should then be planned for each single patient to identify and treat not only one, but all concomitant risk factors and potential different cardioembolic sources. It could also be suggested to have, for each single candidate patient, a second independent opinion from physicians not involved in the procedure and possibly not operating in the same institution. This prudential approach could reduce in each single case the risk of uselessness, futility and even potential harm and adverse events of those procedures.

  13. Left atrial appendage occlusion with the AMPLATZER Amulet device: an expert consensus step-by-step approach.

    Science.gov (United States)

    Tzikas, Apostolos; Gafoor, Sameer; Meerkin, David; Freixa, Xavier; Cruz-Gonzalez, Ignacio; Lewalter, Thorsten; Saw, Jacqueline; Berti, Sergio; Nielsen-Kudsk, Jens Erik; Ibrahim, Reda; Lakkireddy, Dhanunjaya; Paul, Vincent; Arzamendi, Dabit; Nietlispach, Fabian; Worthley, Stephen G; Hildick-Smith, David; Thambo, Jean Benoit; Tondo, Claudio; Aminian, Adel; Kalarus, Zbigniew; Schmidt, Boris; Sondergaard, Lars; Kefer, Joelle; Meier, Bernhard; Park, Jai-Wun; Sievert, Horst; Omran, Heyder

    2016-04-20

    This document aims to describe a standardised methodology for performing left atrial appendage occlusion (LAAO) using the AMPLATZER Amulet device, and to provide useful tips and tricks for operators with different levels of experience. Physicians who are experts in LAAO and had personal clinical experience with the AMPLATZER Amulet device were asked to contribute in the preparation of this consensus document. Twenty-seven physicians (20 interventional cardiologists and 7 electrophysiologists) from 14 different countries reviewed the manuscript. A step-by-step approach, simulating a real case, was followed. Starting with patient selection and planning, related cardiac imaging is discussed, followed by vascular access - transseptal puncture optimisation. Then, angiographic calibration/sizing and the required fluoroscopy views are explained and a device sizing strategy is proposed. Device preparation and de-airing is briefly described, followed by sheath exchange, device deployment steps, evaluation of device stability and decision for final release. The way to recapture and change a device is then shown, together with some additional tips on how to deal with challenging anatomies like "chicken wing" left atrial appendage. Finally, for operators who are switching from AMPLATZER Cardiac Plug to Amulet, the main differences between the two devices with respect to implantation technique are presented. In conclusion, this document reflects a consensus approach by expert implanters on the steps of LAAO technique and best practices for implantation of the AMPLATZER Amulet device, along with some practical tips to minimise the complication rate.

  14. Pulmonary artery perforation and coronary air embolism-two fatal outcomes in percutaneous left atrial appendage occlusion.

    Science.gov (United States)

    Zwirner, J; Bayer, R; Hädrich, C; Bollmann, A; Klein, N; Dreßler, J; Ondruschka, B

    2017-01-01

    Percutaneous left atrial appendage (LAA) closure is a routinely performed method to reduce the risk of stroke in patients suffering from atrial fibrillation, when an oral anticoagulation is no longer indicated due to relevant bleeding complications. Currently, the Amplatzer Amulet and the Watchman system are two equally used systems. While there is an acute success rate of more than 95 per cent for this intervention, several minor and major complications such as pericardial effusions, air embolism, vascular lesions in proximity to the heart or even death can occur. Here, we report two cases of very rare fatal outcomes in percutaneous LAA occlusion. Eight hours after deployment of an Amplatzer Amulet a patient died, after the pulmonary trunk was perforated by a hook of the occluder device causing pericardial tamponade. In the second case during final radiological position control of the deployed Watchman occluder air was injected accidentally. The patient immediately died due to coronary air embolism. Forensic autopsies are necessary to solve the cause and manner of death, to evaluate and develop medical devices and to rule out medical malpractice. Thus, a close collaboration of legal medicine and the various cardiologic departments is proposed.

  15. Motion of left atrial appendage as a determinant of thrombus formation in patients with a low CHADS2 score receiving warfarin for persistent nonvalvular atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Ono Koji

    2012-12-01

    Full Text Available Abstract Background The aim of this study was to define the independent determinants of left atrial appendage (LAA thrombus among various echocardiographic parameters measured by Velocity Vector Imaging (VVI in patients with nonvalvular atrial fibrillation (AF receiving warfarin, particularly in patients with a low CHADS2 score. Methods LAA emptying fraction (EF and LAA peak longitudinal strain were measured by VVI using transesophageal echocardiography in 260 consecutive patients with nonvalvular persistent AF receiving warfarin. The patients were divided into two groups according to the presence (n=43 or absence (n=217 of LAA thrombus. Moreover, the patients within each group were further divided into subgroups according to a CHADS2 score ≤1. Results Multivariate logistic regression analysis showed that LAAEF was an independent determinant of LAA thrombus in the subgroup of 140 with a low CHADS2 score. Receiver operating characteristics curve analysis showed that an LAAEF of 21% was the optimal cutoff value for predicting LAA thrombus. Conclusions LAA thrombus formation depended on LAA contractility. AF patients with reduced LAA contractile fraction (LAAEF ≤21% require strong anticoagulant therapy to avoid thromboembolic events regardless of a low CHADS2 score (≤1.

  16. Left atrial appendage occlusion versus standard medical care in patients with atrial fibrillation and intracerebral haemorrhage: a propensity score-matched follow-up study.

    Science.gov (United States)

    Nielsen-Kudsk, Jens Erik; Johnsen, Søren Paaske; Wester, Per; Damgaard, Dorte; Airaksinen, Juhani; Lund, Juha; De Backer, Ole; Pakarinen, Sami; Odenstedt, Jacob; Vikman, Saila; Settergren, Magnus; Kongstad, Ole; Rosenqvist, Mårten; Krieger, Derk W

    2017-06-20

    The aim of this study was to investigate the prognosis in patients with atrial fibrillation (AF) and intracerebral haemorrhage (ICH) having a left atrial appendage occlusion (LAAO) versus patients receiving standard medical therapy. A total of 151 patients from the Nordic countries with AF and previous ICH who underwent LAAO using the AMPLATZER Cardiac Plug or the AMPLATZER AMULET were compared to a propensity score-matched group of 151 patients receiving standard medical therapy. The two groups were matched so that their risks for stroke and bleeding were similar (CHA2DS2-VASc and HAS-BLED scores). The standard care patients were identified from the Danish Stroke Registry among 787 patients with AF and ICH. The primary endpoint was a composite of all-cause mortality, ischaemic stroke and major bleeding. Patients with AF and a prior ICH treated with LAAO had a lower risk of the composite outcome as compared to patients treated with standard medical care (events/1,000 years [95% confidence interval]: 53.3 [44.3-64.1] vs. 366.7 [298.2-450.9]; hazard ratio 0.16 [0.07-0.37]). LAAO is suggested to be of major clinical benefit in AF patients having sustained an ICH. These results have to be confirmed in a randomised clinical trial.

  17. Percutaneous left atrial appendage occlusion – treatment outcomes and 6 months of follow-up – a single-center experience

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    Karczewski, Michał; Skowronek, Radomir; Burysz, Marian; Fischer, Marcin; Anisimowicz, Lech; Demkow, Marcin; Konka, Marek; Ogorzeja, Wojciech

    2016-01-01

    Aim To present the results of treatment and evaluate 6 months of follow-up in a group of patients with non-valvular atrial fibrillation, who underwent the procedure of percutaneous left atrial appendage occlusion (PLAAO). Material and methods Percutaneous left atrial appendage occlusion was performed in 34 patients with non-valvular atrial fibrillation and contraindications for oral anticoagulation therapy. The risk of thromboembolic and bleeding complications was determined based on the CHA2DS2VASc and HAS-BLED scales. The Amplatzer Amulet system from St. Jude Medical was used. On the first postoperative day, all patients were started on double antiplatelet therapy with 75 mg/day of acetylsalicylic acid (ASA) and 75 mg/day of clopidogrel (CLO). On the 30th postoperative day, the efficacy of the antiplatelet therapy was assessed with impedance aggregometry using a Multiplate analyzer (Roche). Echocardiographic examinations were performed intraoperatively and on the first postoperative day; subsequently, follow-up examinations were conducted 1 and 6 months after the implantation. Results In all patients, proper occluder position was observed throughout the follow-up. No leakage or thrombi around the implants were found. No strokes or bleeding complications associated with the antiplatelet therapy were observed. Multiplate assessment of platelet activity was conducted in 20 out of 34 patients. The efficacy of ASA treatment was demonstrated in all patients; no response to clopidogrel treatment was observed in 5 out of 20 patients. One patient suffered from cardiac tamponade, which required the performance of full sternotomy. Local complications (hematomas of the inguinal region) were observed in 3 patients. One of the patients died for reasons unrelated to the procedure. Conclusions Percutaneous left atrial appendage occlusion is an effective procedure in patients with non-valvular atrial fibrillation and contraindications for chronic anticoagulation therapy. Further

  18. Light and electron microscopic features of surgically excised left atrial appendage in rheumatic heart disease patients with atrial fibrillation and sinus rhythm.

    Science.gov (United States)

    Sharma, Shruti; Sharma, Gautam; Hote, Milind; Devagourou, V; Kesari, Vikas; Arava, Sudhir; Airan, Balram; Ray, Ruma

    2014-01-01

    There are few studies comparing the pathology of the remodeled substrate in patients of rheumatic heart disease with atrial fibrillation (AF) and normal sinus rhythm (NSR). The study group comprised 30 patients with rheumatic heart disease undergoing mitral valve replacement. Excised left atrial appendages of these patients [17 with persistent AF and 13 NSR (control group)] were subjected to light and electron microscopic examination. The histopathological findings of the myocardium were characterized by cardiomyocyte hypertrophy (CH), nuclear enlargement (NE), perinuclear clearing (PC), sarcoplasmic vacuolation (SV), fibrosis, and inflammation in the patients with AF and NSR. NE (17/17 vs. 4/13; P=.004), PC (17/17 vs. 4/13; P=.004), SV (17/17 vs. 9/13; P=.06), and fibrosis (15/17 vs. 3/13; P=.001) were all significantly more common in patients with AF. Inflammatory cells were observed in 9/17 patients of AF as compared to 1 in NSR patients (9/17 vs. 1/13; P=.02). CH was common in the patients with AF as compared with those in NSR (17/17 vs. 10/13; P=.103). In AF patients, electron microscopy revealed cardiomyocytes with depletion of the contractile elements (Z-bands), glycogen particle accumulation, and an increase in mitochondria. Cells severely affected by AF showed loss of contractile elements with extensive areas of SV, presence of myelin figures, and mitochondrial aggregates. Majority of AF cases showed extensive fibrosis in the form of collagen bundles in the interstitium. The left atrial substrate in AF as compared with NSR, in rheumatic heart disease patients, is associated with significant degenerative remodeling and ongoing inflammation that is associated with extensive fibrosis. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Ionic Remodeling and Direct Effects of Valsartan on Ionic Currentsin Human Atrial Myocytes with Atrial Fibrillation

    Institute of Scientific and Technical Information of China (English)

    Xue Yumei; Wu Shulin; Deng Chunyu; Qian Weimin; Chen Chunbo

    2004-01-01

    Objectives Previous studies demonstrated that angiotensin receptor antagonists had effects on some potassium channels in guinea pig myocytes and cloned channels that expressed in human cardiac myocytes. This study determined the direct effects of Valsartan on I caL, INa, IKur, IK1 and Ito1 in isolated human atrial myocytes. Methods and Results Specimens of right atrial appendage tissue were obtained from 39 patients with coronary artery and valvular heart diseases during cardiopulmonary bypass procedure. Pre- operation cardiac rhythm was sinus (SR)in 19 patients and was atrial fibrillation (AF) in the others. Single atrial myocyte was isolated by enzymatic dissociation with the chunk method. The ionic currents were recorded using the whole cell coffiguration of the voltage clamp technique. ICaL and Ito1 densities in AF patients were significantly lower than those in SR patients by 74% and 60%, respectively, while IK1density was significantly higher by 34% at command potential of - 120 mV. With 10 μmol/L Valsartan, INa density was significantly decreased by 59% in SR patients and by 66% in AF patients. IKur and IKl density were significantly decreased in only AF patients by 31% and23%, respectively. Conclusions Conclusions Decreased IcaL and Itol and increased IKl at hyperpolarizing potentials in AF patients' atrial myocytes may result from the electrophysiological remodeling by AF. Valsartan significantly decreases INa, IK1 and IKur current densities in AF patients' myocyte, but decreases only INa in SR patients' myocyte, suggesting that Valsartan may be beneficial to the recovering of remolded atria.

  20. The Value of 3D Printing Models of Left Atrial Appendage Using Real-Time 3D Transesophageal Echocardiographic Data in Left Atrial Appendage Occlusion: Applications toward an Era of Truly Personalized Medicine.

    Science.gov (United States)

    Liu, Peng; Liu, Rijing; Zhang, Yan; Liu, Yingfeng; Tang, Xiaoming; Cheng, Yanzhen

    2016-01-01

    The objective of this study was to assess the clinical feasibility of generating 3D printing models of left atrial appendage (LAA) using real-time 3D transesophageal echocardiogram (TEE) data for preoperative reference of LAA occlusion. Percutaneous LAA occlusion can effectively prevent patients with atrial fibrillation from stroke. However, the anatomical structure of LAA is so complicated that adequate information of its structure is essential for successful LAA occlusion. Emerging 3D printing technology has the demonstrated potential to structure more accurately than conventional imaging modalities by creating tangible patient-specific models. Typically, 3D printing data sets are acquired from CT and MRI, which may involve intravenous contrast, sedation, and ionizing radiation. It has been reported that 3D models of LAA were successfully created by the data acquired from CT. However, 3D printing of the LAA using real-time 3D TEE data has not yet been explored. Acquisition of 3D transesophageal echocardiographic data from 8 patients with atrial fibrillation was performed using the Philips EPIQ7 ultrasound system. Raw echocardiographic image data were opened in Philips QLAB and converted to 'Cartesian DICOM' format and imported into Mimics® software to create 3D models of LAA, which were printed using a rubber-like material. The printed 3D models were then used for preoperative reference and procedural simulation in LAA occlusion. We successfully printed LAAs of 8 patients. Each LAA costs approximately CNY 800-1,000 and the total process takes 16-17 h. Seven of the 8 Watchman devices predicted by preprocedural 2D TEE images were of the same sizes as those placed in the real operation. Interestingly, 3D printing models were highly reflective of the shape and size of LAAs, and all device sizes predicted by the 3D printing model were fully consistent with those placed in the real operation. Also, the 3D printed model could predict operating difficulty and the

  1. Left atrial appendage closure using the Amulet device: an initial experience with the second generation amplatzer cardiac plug.

    Science.gov (United States)

    Lam, Simon Cheung Chi; Bertog, Stefan; Gafoor, Sameer; Vaskelyte, Laura; Boehm, Patrick; Ho, Raymond Wei Jian; Franke, Jennifer; Hofmann, Ilona; Sievert, Horst

    2015-02-01

    Aim of this study was to demonstrate the feasibility, safety, and short-term outcome of left atrial appendage (LAA) closure with a new generation LAA closure device. The Amulet device (AGA, St Jude Medical, Minneapolis, MN) is a new generation of the amplatzer cardiac plug (ACP), specifically designed for LAA closure. This new version is designed to facilitate the implantation process and minimize procedural or device-related complications. The device was implanted in 17 patients with nonvalvular atrial fibrillation (AF). Clinical data were obtained at baseline, during the procedure, at discharge, at 30 and 90 days. All devices were implanted successfully. Device sizes ranged from 20 mm to 31 mm. A 12 French (Fr) or 14 Fr delivery sheath was used depending on the selected device size. Full and partial recapture was performed in 1 case and 3 cases, respectively. There was 1 procedure-related pericardial effusion successfully managed with pericardiocentesis. There was no device embolization. The mean length of stay was 2.1 ± 0.3 days. At 90 days, there were no deaths, strokes, systemic thromboembolism, or bleeding complications. There was no device-related thrombus or pericardial effusion at 90-day TEE. In 2 of the 17 patients minimal peridevice flow (smaller than 2 mm) was present. The Amulet device, which has new novel features as compared with the first generation ACP, is a feasible option for LAA closure. From our initial experience, implantation of the Amulet is associated with high success rate and good short-term outcome. © 2014 Wiley Periodicals, Inc.

  2. Safety and efficacy of catheter-based left atrial appendage closure in patients with contraindications for long-term anticoagulation.

    Science.gov (United States)

    Seidel, Adrian; Parwani, Abdul S; Krackhardt, Florian; Huemer, Martin; Attanasio, Philipp; Haverkamp, Wilhelm; Pieske, Burkert; Boldt, Leif-Hendrik

    2017-05-31

    Percutaneous left atrial appendage closure (LAAC) and the role of post interventional anticoagulation often evokes controversy in daily practice. This study aimed to evaluate LAAC in patients with non-rheumatic atrial fibrillation, high thromboembolic risk and contraindications for long-term anticoagulation in a clinical scenario. Between 2010-2015, LAAC was attempted in 118 patients (47 women). Devices were successfully implanted in 95% (Watchman™ device n=97, St. Amplatzer™ Cardiac Plug/Amulet n=14, Amplatzer PFO Occluder n=1). Mean age, HAS-BLED and CHA2DS2VASc score were 75 years (SD 8.35yrs), 4.3 and 4.9, respectively. Median followup was 447 days (P25=183d, P75=789d). The primary safety endpoint was defined as major bleeding according to the International Society on Thrombosis and Haemostasis. The combined efficacy endpoint included ischemic strokes, transitory ischemic attacks (TIA) and systemic embolisms. Procedural complication rate was 3.4%. After successful intervention, either a therapy with anticoagulants (n=62) or dual antiplatelet therapy (DAPT, n=50) was prescribed temporarily. Medication was reduced if implantation proved satisfying in a 6-week follow-up transesophageal echocardiography, which was the case in 79% of these patients. During follow-up, one patient suffered a TIA (0.6%/year). No other efficacy event was observed. 11 major bleedings occurred (6.6%/year): one each under DAPT plus phenprocoumon, DAPT plus rivaroxaban, acetylsalicylic acid (ASA) plus rivaroxaban, two under DAPT, two under ASA plus low molecular weight heparin, and four under ASA only. In our analysis, catheter-based LAA occlusion prevented thromboembolisms with high efficacy. Major bleedings were however common in patients with, but also without anticoagulation, independent from time course.

  3. Comparison of the Feasibility and Safety of First- versus Second-Generation AMPLATZER™ Occluders for Left Atrial Appendage Closure

    Directory of Open Access Journals (Sweden)

    Baravan Al-Kassou

    2017-01-01

    Full Text Available Introduction. Left atrial appendage closure (LAAC is considered an alternative to oral anticoagulation therapy in patients with atrial fibrillation (AF. The aim of this study was to compare the safety and efficacy of the first- and second-generation AMPLATZER Devices for LAAC, AMPLATZER Cardiac Plug (ACP versus AMPLATZER Amulet™. Methods. Procedural data, such as fluoroscopy time, radiation dose, and contrast-dye, as well as VARC criteria and major adverse events (MAEs were assessed for both devices. The rate of peridevice leaks was analyzed at echocardiographic follow-up. Results. A total of 196 patients with AF underwent LAAC with the ACP (n=99 or Amulet device (n=97. The use of Amulet was associated with significantly lower fluoroscopy time (14.8 ± 7.4 min versus 10.6 ± 4.1 min; p<0.001, lower radiation dose (4833 ± 3360 cGy⁎cm2 versus 3206 ± 2169 cGy⁎cm2; p<0.001, and reduced amount of contrast-dye (150.2 ± 83.9 ml versus 128.8 ± 46.0 ml; p=0.03. Furthermore, LAAC with Amulet devices resulted in lower device-resizing rates (3 versus 16 cases; p=0.001. Peridevice leaks were less frequent in the Amulet group (12 versus 4; p=0.03. MAE occurred in 6 ACP and 4 Amulet patients (p=0.58. Conclusions. The Amulet device is associated with shorter fluoroscopy times and radiation dosages, reduced use of contrast-dye, lower recapture rates, and less peridevice leaks as compared to the ACP.

  4. Quantitative Evaluation of the Substantially Variable Morphology and Function of the Left Atrial Appendage and Its Relation with Adjacent Structures.

    Science.gov (United States)

    Li, Cai-Ying; Gao, Bu-Lang; Liu, Xiao-Wei; Fan, Qiong-Ying; Zhang, Xue-Jing; Liu, Guo-Chao; Yang, Hai-Qing; Feng, Ping-Yong; Wang, Yong; Song, Peng

    2015-01-01

    To investigate quantitatively the morphology, anatomy and function of the left atrial appendage (LAA) and its relation with adjacent structures. A total of 860 patients (533 men, 62.0%, age 55.9±10.4 year) who had cardiac multidetector computed tomography angiography from May to October 2012 were enrolled for analysis. Seven types and 6 subtypes of LAA morphology were found with Type 2 being the most prevalent. Type 5 was more significantly (Pwater drop-like in 3.2%, round in 2.4% and foot-like in 1.6%. The LAA orifice had a significantly greater (Pvolume, aortic cross area long axis or LSPV long axis but poor correlation with the height, weight, surface area and vertebral body height of the patients. Four types of LAA ridge were identified: AI, AII, B and C with the distribution of 17.6%, 69.9%, 5.9% and 6.6%, respectively. The LAA had a significantly (Pvolume at 45% phase but the least volume at 5% phase. The LAA maximal, minimal and emptying volumes were all significantly (Pvolume but no correlation with the maximal volume. The LAA has substantially variable morphologies and relation with the adjacent structures, which may be helpful in guiding the LAA trans-catheter occlusion or catheter ablation procedures.

  5. Assessment of normal left atrial appendage anatomy and function over gender and ages by dynamic cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Boucebci, Samy; Velasco, Stephane; Duboe, Pier-Olivier; Tasu, Jean-Pierre [University of Poitiers, University Hospital, Department of Radiology, Poitiers (France); Pambrun, Thomas [University of Poitiers, University Hospital, Department of Cardiology, Poitiers (France); Ingrand, Pierre [University of Poitiers, University Institute of Public Health, Poitiers (France)

    2016-05-15

    The aim of this study was to evaluate variations in anatomy and function according to age and gender using cardiac computed tomography (CT) in a large prospective cohort of healthy patients. The left atrial appendage (LAA) is considered the most frequent site of intracardiac thrombus formation. However, variations in normal in vivo anatomy and function according to age and gender remain largely unknown. Three-dimensional (3D) cardiac reconstructions of the LAA were performed from CT scans of 193 consecutive patients. Parameters measured included LAA number of lobes, anatomical position of the LAA tip, angulation measured between the proximal and distal portions, minimum (iVol{sub min}) and maximum (iVol{sub max}) volumes indexed to body surface area (BSA), and ejection fraction (LAAEF). Relationship with age was assessed for each parameter. We found that men had longer and wider LAAs. The iVol{sub min} and iVol{sub max} increased by 0.23 and 0.19 ml per decade, respectively, while LAAEF decreased by 2 % per decade in both sexes. Although LAA volumes increase, LAAEF decreases with age in both sexes. (orig.)

  6. Postoperative pulmonary hypertensive crisis caused by inverted left atrial appendage after cardiopulmonary bypass surgery for congenital heart disease in a neonate.

    Science.gov (United States)

    Zhao, Qifeng; Hu, Xingti

    2013-09-01

    Postoperative pulmonary hypertensive crisis (PHC) caused by an inverted left atrial appendage (ILAA) is a rare complication following cardiac surgery. We present a case of 23 day-old male infant who developed postoperative PHC attacks after undergoing cardiopulmonary bypass (CPB) surgery for repair of the coactation of aorta. A hyperechogenic left atrial mass was detected via bedside transthoracic echocardiography (TTE), which was identified as an ILAA and corrected following repeat surgery. In this case, both the negative pressure in vent catheter and the long left atrial appendage (LAA) with a narrow base led to an irreversible ILAA. As in this neonate, ILAA had significant influence on the left atrial volume and caused PHC since the ILAA was located on the mitral valve orifice and interfered with the blood flow through the valve. Therefore, we recommend that the vent catheter should be turned off before removing to avoid this potential complication. Additionally, LAA should be carefully inspected after CPB surgery, and intra-operative and post-operative transoesophageal echocardiography (TEE) should be performed to detect ILAA intraoperatively so as to avoid the reoperation. When an ILAA is diagnosed postoperatively, whether conservative treatment or surgery will depend on the balance of benefit and risk for a particular patient.

  7. Transcatheter left atrial appendage occlusion in patients with atrial fibrillation and a high bleeding risk using aspirin alone for post-implant antithrombotic therapy.

    Science.gov (United States)

    Korsholm, Kasper; Nielsen, Kirsten Melgaard; Jensen, Jesper Møller; Jensen, Henrik Kjærulf; Andersen, Grethe; Nielsen-Kudsk, Jens Erik

    2017-04-20

    The aim of the study was to evaluate the safety and efficacy of left atrial appendage occlusion (LAAO) with the AMPLATZER Cardiac Plug (ACP) or Amulet using aspirin alone (ASA) as post-implantation antithrombotic treatment. This was a single-centre, prospective, non-randomised study on LAAO with the ACP or Amulet in a consecutive cohort (n=110) treated by ASA alone post implantation. The primary outcome was device-related thrombosis, while secondary outcomes were ischaemic stroke or major bleeding. Clinical follow-up was conducted after six weeks and 12 months with TEE and cardiac CT. One hundred and seven patients were included in the analysis. Three patients were excluded due to a mechanical valve prosthesis. CHA2DS2-VASc score was 4.4±1.6 and HAS-BLED 4.1±1.1. Successful implantation was obtained in all patients with a periprocedural complication rate of 4.6%. Median follow-up was 2.3 years, with a total of 265 patient-years. Device-related thrombosis was detected in 2/107 (1.9%) cases. Stroke occurred in 6/107 patients, with an annualised rate of 2.3%, which is a 61% risk reduction compared to the predicted rate. Annual risk of major bleeding was reduced by 57%. LAAO with the ACP or Amulet was safely performed with ASA monotherapy after implantation without an increased risk of device-related thrombosis or stroke.

  8. Left atrial appendage morphology and risk of stroke following pulmonary vein isolation for drug-refractory atrial fibrillation in low CHA2DS2Vasc risk patients.

    Science.gov (United States)

    Kelly, Faith R; Hull, Robert A; Arrey-Mbi, Takor B; Williams, Michael U; Lee, Joshua S; Slim, Ahmad M; Thomas, Dustin M

    2017-02-28

    Cardiac CT angiography (CCTA) has become an important adjunct in the structural assessment of the pulmonary veins (PV) prior to pulmonary vein isolation (PVI). Published data is conflicting regarding a relationship between left atrial appendage (LAA) and the risk of ischemic stroke (CVA) following PVI. We investigated the associations of volumetric and morphologic left atrial (LA) and LAA measurements for CVA following PVI. We retrospectively reviewed 332 consecutive patients with drug refractory atrial fibrillation who obtained cardiac CT angiogram (CCTA) prior to PVI. Baseline demographic data, procedural and lab details, and outcomes were obtained from abstraction of an electronic medical records system. LA, LAA, and PV volumes were measured using CCTA datasets utilizing a semi-automated 3D workstation application. LAA morphology was assigned utilizing volume rendered images as previously described. The study cohort was 55 ± 13 years-old, 83.7% male, low CVA risk (median CHA2DS2Vasc 1; IQR 1, 3), and 30.4% were treated with novel oral anticoagulants. Chicken wing (CW) was the most common morphology (52%), followed by windsock (WS), cauliflower (CF), and cactus (CS) at 18, 9, and 2%, respectively. CVAs occurred in 4 patients following PVI with median time to CVA of 170.5 days. All CVAs were observed in CW morphology patients. When comparing CW morphology with non-CW morphology, CVAs occurred more frequently with the CW morphology (2.1% vs 0%, p = 0.03). This difference was not significant, though, after adjusting for CHA2DS2Vasc risk factors (p = 0.14). The CW morphology was observed more commonly in patients who experienced post-PVI CVA. After adjusting for CHA2DS2Vasc risk factors, CW morphology was not an independent predictor of post-PVI CVA. These findings should be interpreted in the setting of a low CVA event rate amongst a low risk population that was highly compliant with indicated anticoagulation therapy.

  9. A comparison of two-dimensional and real-time 3D transoesophageal echocardiography and angiography for assessing the left atrial appendage anatomy for sizing a left atrial appendage occlusion system: impact of volume loading.

    Science.gov (United States)

    Al-Kassou, Baravan; Tzikas, Apostolos; Stock, Friederike; Neikes, Fabian; Völz, Alexander; Omran, Heyder

    2017-04-20

    Correct sizing of a left atrial appendage (LAA) closure system is important to avoid redeployment of the device and peri-device leaks. The aims of this study were to assess the significance of two-dimensional transoesophageal echocardiography (2D-TEE), real-time 3D transoesophageal echocardiography (RT 3D-TEE) and angiography for measuring the size of the LAA landing zone and to determine the impact on sizing an LAA closure device. Furthermore, we investigated the relevance of volume loading on LAA size. In a prospective study, 46 patients underwent 2D-TEE and RT 3D-TEE 24 hours prior to LAA closure, at the beginning of the procedure and just before the procedure after volume loading with an average of 1,035±246 ml. Angiography was performed immediately before the implantation. Maximal diameter (2.2±0.4 versus 2.3±0.4 cm; pcorrelation (R) between measurements and LAA device size was found for RT 3D-TEE-derived perimeter (R=0.97) and area (R=0.96), whereas the maximal diameter (R=0.78) measured by 2D-TEE and angiography (R=0.76) correlated less closely. Sizing based on an RT 3D-TEE-measured perimeter resulted only in 4% of undersizing the implanted device. Peri-device leaks occurred in seven cases (15%) and were associated with a lower compression of LAA devices (7±1.3% versus 14±3.2% for patients without leaks, pcorrelation to LAA closure device size than 2D-TEE or angiographic measurements.

  10. Left atrial appendage closure device implantation and pulmonary vein isolation as a comprehensive treatment for atrial fibrillation

    Directory of Open Access Journals (Sweden)

    А. А. Якубов

    2016-01-01

    Full Text Available Objective. This randomized clinical trial was designed to assess the impact of pulmonary vein isolation (PVI combined with LAA occlusion on patients with high-risk AF. Methods. Patients with a history of symptomatic paroxysmal (P AF and/or persistent (Pers AF and CHA2DS2-VASc score ≥2 and HAS-BLED score ≥3 were randomized in groups with PVI only (n = 44 and PVI combined with LAA occlusion (n = 45. All patients were followed during 24 months in order to evaluate the safety of thromboembolic complications and to monitor the heart rhythm conducted by means of an implantable cardiac monitor. Results. 6 patients from the PVI with LAA occlusion group were transferred to the PVI only group because of a failure to implant a LAA closure device. Based on ILR data, by the end of the follow-up 33 (66% out of 50 patients in the PVI only group and 23 (59% out of 39 patients in the PVI with LAA closure device implantation group were free from atrial fibrillation and flutter without antiarrhythmic drugs (p = 0.34. In the blanking period, AF% was significantly higher in the PVI with LAA closure group than that in the PVI-only group, 9.7±10.8 and 4.2±4.1% respectively (p = 0.004. After the blanking period, the AF% was similar in both groups. During the entire follow-up, no AF/intervention-related complications were observed. Conclusion. The combination of LAA closure device implantation with PVI seems to be a safe procedure. However, it does not improve the efficacy of PVI in patients with symptomatic refractory AF. But in the blanking period LAA occlusion increases AF %.

  11. Roles of real-time three-dimensional transesophageal echocardiography in peri-operation of transcatheter left atrial appendage closure

    Science.gov (United States)

    Zhou, Qing; Song, Hongning; Zhang, Lan; Deng, Qing; Chen, Jinling; Hu, Bo; Wang, Yijia; Guo, Ruiqiang

    2017-01-01

    Abstract Left atrial appendage (LAA) closure is a new treatment option for the prevention of stroke in patients with nonvalvular atrial fibrillation (AF). Conventional 2-dimensional transesophageal echocardiography (2D TEE) has some limitations in the imaging assessment of LAA closure. Real-time 3-dimensional transesophageal echocardiography (RT-3D TEE) allows for detailed morphologic assessment of the LAA. In this study, we aim to determine the clinical values of RT-3D TEE in the periprocedure of LAA closure. Thirty-eight persistent or paroxysmal AF patients with indications for LAA closure were enrolled in this study. RT-3D TEE full volume data of the LAA were recorded before operation to evaluate the anatomic feature, the landing zone dimension, and the depth of the LAA. On this basis, selection of LAA closure device was carried out. During the procedure, RT-3D TEE was applied to guide the interatrial septal puncture, device operation, and evaluate the occlusion effects. The patients were follow-up 1 month and 3 months postclosure. Twenty-eight (73.7%) patients with AF received placement of LAA occlusion device under RT-3D TEE. Eleven cases with single-lobe LAAs were identified using RT-3D TEE, among which 4 showed limited depth. Seventeen cases showed bilobed or multilobed LAA. Seven cases received LAA closure using Lefort and 21 using LAmbre based on the 3D TEE and radiography. The landing zone dimension of the LAA measured by RT-3D TEE Flexi Slice mode was better correlated with the device size used for occlusion (r = 0.90) than 2D TEE (r = 0.88). The interatial septal puncture, the exchange of the sheath, as well as the release of the device were executed under the guidance of RT-3D TEE during the procedure. The average number of closure devices utilized for optimal plugging was (1.11 ± 0.31). There were no clinically unacceptable residual shunts, pericardial effusion, or tamponade right after occlusion. All the patients had the device well

  12. Intracardiac Echocardiography From the Left Atrium for Procedural Guidance of Transcatheter Left Atrial Appendage Occlusion.

    Science.gov (United States)

    Korsholm, Kasper; Jensen, Jesper Møller; Nielsen-Kudsk, Jens Erik

    2017-08-24

    The aim of this study was to compare the efficacy and safety of intracardiac echocardiography (ICE) from the left atrium (LA) with transesophageal echocardiography (TEE) for procedural guidance of transcatheter left atrial appendage occlusion (LAAO). TEE with general anesthesia is the current gold standard to guide LAAO. By the use of ICE from the LA, LAAO can be performed in local anesthesia and may potentially have advantages over TEE. A single-center, cohort study of patients undergoing LAAO with the Amplatzer Cardiac Plug or Amulet (St. Jude Medical, St. Paul, Minnesota). Procedures were guided by ICE from the LA with local anesthesia (n = 109) or TEE using general anesthesia (n = 107). All patients had pre-procedural cardiac computed tomography. Efficacy outcomes were technical success, procedural success, and peridevice leakage at TEE 8 weeks after LAAO. Safety outcome was a composite of periprocedural complications. Technical success was achieved in 99% of both the TEE and ICE group. Procedural success was similar between groups: 94.4% success rate in the TEE-guided group, and 94.5% in the ICE-guided group. Major periprocedural complications occurred in 4.7% of the TEE group and 1.8% of the ICE group. Rate and degree of peridevice leak did not differ between groups at follow-up. Turnover time in the catheter laboratory, and contrast use were reduced with ICE. LA ICE to guide LAAO as compared with TEE appears to be effective and safe, without increased procedure-related complications. The rate of peridevice leak is low and similar to TEE-guided procedures. Time spent in the catheterization room may decrease substantially. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  13. Efficacy and Safety of the WATCHMAN Left Atrial Appendage System for Stroke Prevention in Chinese Patients with Nonvalvular Atrial Fibrillation: A Single-center, Prospective, Observational Study

    Science.gov (United States)

    Huang, Wei-Ping; Zhang, Yong-Hua; He, Lei; Su, Xi; Yang, Xin-Wei; Guo, Zai-Xiong

    2017-01-01

    Background: In patients with nonvalvular atrial fibrillation (NVAF), embolic stroke is thought to be associated with left atrial appendage (LAA) thrombi. The WATCHMAN LAA Occlusion Device has been shown to be noninferior to conventional oral anticoagulation with warfarin for stroke prevention in patients with NVAF. This study aimed to evaluate the procedural feasibility, safety and 12-month outcomes of the WATCHMAN LAA Occlusion Device in NVAF patients with high risk for stroke in China. Methods: The clinical data of 106 NVAF patients, who were consecutively underwent LAA closure with the WATCHMAN Device between April 2014 and May 2015, were collected. Patients were followed up at 1, 3, 6, and 12 months after discharge. A transesophageal echocardiograph was performed at 45 days after implantation and repeated in case of an unexpected event during the follow-up period. Results: This study included 106 NVAF patients with a mean age of 64.2 ± 8.6 years (ranging from 50 to 88 years), and the mean CHA2DS2-VASc score of all patients was 3.6 ± 1.6 (ranging from 2 to 9). Among those 106 NVAF patients, 100 (94.3%) patients were implanted with the device successfully. The procedural success rate was 94.3% (100/106), and the occlusion rate was 100.0% (100/100). There were one tamponade, one ischemic stroke, and eight minor pericardial effusions during hospitalization. During 12-month follow-up period, two patients developed a thrombus layer on the device that resolved with additional anticoagulation: one with visible device-thrombus experienced transient ischemic stroke, and one had a hemorrhagic stroke. There were no deaths in this study. The overall survival rate was 100.0%, and nonmajor adverse event rate was 95.0% (95/100). In this study, the expected annual rate of ischemic stroke risk in these patients according to the CHA2DS2-VASc score was 4.0%, while the observed ischemic stroke rate was 2.0% per year. Conclusions: LAA closure with the WATCHMAN Device was feasible

  14. The New 3D Printed Left Atrial Appendage Closure with a Novel Holdfast Device: A Pre-Clinical Feasibility Animal Study.

    Directory of Open Access Journals (Sweden)

    M Brzeziński

    Full Text Available Many patients undergoing cardiac surgery have risk factors for both atrial fibrillation (AF and stroke. The left atrial appendage (LAA is the primary site for thrombi formation. The most severe complication of emboli derived from LAA is stroke, which is associated with a 12-month mortality rate of 38% and a 12-month recurrence rate of 17%. The most common form of treatment for atrial fibrillation and stroke prevention is the pharmacological therapy with anticoagulants. Nonetheless this form of therapy is associated with high risk of major bleeding. Therefore LAA occlusion devices should be tested for their ability to reduce future cerebral ischemic events in patients with high-risk of haemorrhage.The aim of this study was to evaluate the safety and feasibility of a novel left atrial appendage exclusion device with a minimally invasive introducer in a swine model.A completely novel LAA device, which is composed of two tubes connected together using a specially created bail, was designed using finite element modelling (FEM to obtain an optimal support force of 36 N at the closure line. The monolithic form of the occluder was obtained by using additive manufacturing of granular PA2200 powder with the technology of selective laser sintering (SLS. Fifteen swine were included in the feasibility tests, with 10 animals undergoing fourteen days of follow-up and 5 animals undergoing long-term observation of 3 months. For one animal, the follow-up was further prolonged to 6 months. The device was placed via minithoracotomy. After the observation period, all of the animals were euthanized, and their hearts were tested for LAA closure and local inflammatory and tissue response.After the defined observation period, all fifteen hearts were explanted. In all cases the full closure of the LAA was achieved. The macroscopic and microscopic evaluation of the explanted hearts showed that all devices were securely integrated in the surrounding tissues. No

  15. Quantitative Evaluation of the Substantially Variable Morphology and Function of the Left Atrial Appendage and Its Relation with Adjacent Structures.

    Directory of Open Access Journals (Sweden)

    Cai-Ying Li

    Full Text Available To investigate quantitatively the morphology, anatomy and function of the left atrial appendage (LAA and its relation with adjacent structures.A total of 860 patients (533 men, 62.0%, age 55.9±10.4 year who had cardiac multidetector computed tomography angiography from May to October 2012 were enrolled for analysis.Seven types and 6 subtypes of LAA morphology were found with Type 2 being the most prevalent. Type 5 was more significantly (P<0.05 present in women (8.0% than in men (4.2%. LAA orifice was oval in 81.5%, triangular in 7.3%, semicircular in 4%, water drop-like in 3.2%, round in 2.4% and foot-like in 1.6%. The LAA orifice had a significantly greater (P<0.01 major axis in men (24.79±3.81 than in women (22.68±4.07. The LAA orifice long axis was significantly (P<0.05 positively correlated with the height, weight and surface area of the patient. The LAA morphology parameters displayed strong positive correlation with the left atrium volume, aortic cross area long axis or LSPV long axis but poor correlation with the height, weight, surface area and vertebral body height of the patients. Four types of LAA ridge were identified: AI, AII, B and C with the distribution of 17.6%, 69.9%, 5.9% and 6.6%, respectively. The LAA had a significantly (P<0.05 greater distance from its orifice to the mitral ring in women than in men. The LAA had two filling and two emptying processes with the greatest volume at 45% phase but the least volume at 5% phase. The LAA maximal, minimal and emptying volumes were all significantly (P<0.05 positively correlated with the body height, weight and surface area, whereas the LAA ejection fraction had an inverse correlation with the LAA minimal volume but no correlation with the maximal volume.The LAA has substantially variable morphologies and relation with the adjacent structures, which may be helpful in guiding the LAA trans-catheter occlusion or catheter ablation procedures.

  16. Relative uptake of minoxidil into appendages and stratum corneum and permeation through human skin in vitro.

    Science.gov (United States)

    Grice, Jeffrey E; Ciotti, Susan; Weiner, Norman; Lockwood, Peter; Cross, Sheree E; Roberts, Michael S

    2010-02-01

    We examined uptake of the model therapeutic agent, minoxidil, into appendages, stratum corneum (SC), and through human skin, under the influence of different vehicles. Quantitative estimation of therapeutic drug deposition into all three areas has not previously been reported. Finite doses of minoxidil (2%, w/v) in formulations containing varying amounts of ethanol, propylene glycol (PG), and water (60:20:20, 80:20:0, and 0:80:20 by volume, respectively) were used. Minoxidil in SC (by tape stripping), appendages (by cyanoacrylate casting), and receptor fluid was determined by liquid scintillation counting. At early times (30 min, 2 h), ethanol-containing formulations (60:20:20 and 80:20:0) caused significantly greater minoxidil retention in SC and appendages, compared to the formulation lacking ethanol (0:80:20). A significant increase in minoxidil receptor penetration occurred with the PG-rich 0:80:20 formulation after 12 h. We showed that deposition of minoxidil into appendages, SC, and skin penetration into receptor fluid were similar in magnitude. Transport by the appendageal route is likely to be a key determinant of hair growth promotion by minoxidil. (c) 2009 Wiley-Liss, Inc. and the American Pharmacists Association.

  17. Oclusão do apêndice atrial esquerdo com o Amplatzer Cardiac Plug em pacientes com fibrilação atrial Left atrial appendage closure with the Amplatzer Cardiac Plug in patients with atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Ênio Eduardo Guérios

    2012-06-01

    Full Text Available FUNDAMENTO: A oclusão percutânea do apêndice atrial esquerdo (OAAE surgiu como alternativa à anticoagulação oral (AO para prevenção do acidente vascular cerebral (AVC em pacientes com fibrilação atrial não-valvular (FANV. OBJETIVO: Relatar os resultados imediatos e o seguimento clínico de pacientes submetidos a OAAE com o Amplatzer Cardiac Plug (ACP em um único centro de referência. MÉTODOS: Oitenta e seis pacientes consecutivos com FANV, contra-indicação à AO e escore CHADS2= 2,6±1,2 foram submetidos a OAAE com implante de ACP. Realizou-se seguimento clínico e ecocardiográfico no mínimo 4 meses após o implante. RESULTADOS: Todos os implantes foram guiados apenas por angiografia. O sucesso do procedimento foi de 99% (1 insucesso por tamponamento cardíaco e consequente suspensão da OAAE. Houve 4 complicações maiores (o tamponamento já referido, 2 AVCs transitórios e uma embolização com retirada percutânea da prótese e duas menores (um derrame pericárdico sem tamponamento e uma pequena comunicação interatrial evidenciada no seguimento. Houve 1 óbito hospitalar após 6 dias, não relacionado à intervenção. Todos os outros pacientes receberam alta sem AO. Após seguimento de 25,9 pacientes-ano (69 pacientes não houve AVCs nem embolizações tardias de próteses. O AAE estava completamente ocluído em 97% dos casos. Seis pacientes apresentaram evidência de trombo sobre a prótese, que desapareceram após reinstituição de AO por 3 meses. CONCLUSÃO: OAAE se associa a um alto índice de sucesso, um índice aceitável de complicações e resultados promissores a médio prazo, podendo ser considerada uma alternativa válida à OA na prevenção do AVC em pacientes com FANV.BACKGROUND: Percutaneous left atrial appendage closure (LAAC has emerged as an alternative to oral anticoagulation (OA for prevention of thromboembolic stroke in patients with non-valvular atrial fibrillation (NVAF. OBJECTIVE: To describe the

  18. Left atrial appendage occlusion with Amplatzer Cardio Plug is an acceptable therapeutic option for prevention of stroke recurrence in patients with non-valvular atrial fibrillation and contraindication or failure of oral anticoagulation with acenocumarol

    Directory of Open Access Journals (Sweden)

    Maximiliano A. Hawkes

    2016-03-01

    Full Text Available ABSTRACT Left atrial appendage occlusion (LAAO appears as a therapeutic option for some atrial fibrillation patients not suitable for oral anticoagulation because an increased hemorrhagic risk or recurrent ischemic events despite anticoagulant treatment. Methods Report of consecutive atrial fibrillation patients treated with LAAO with Amplatzer Cardio Plug because contraindication or failure of oral anticoagulation with acenocumarol. CHA2DS2VASC, HAS-BLED, NIHSS, mRS, procedural complications and outcome were assessed. Seven patients (73 ± 6 year-old were treated after intracerebral (n = 5 and gastrointestinal (n = 1 hemorrhages or ischemic stroke recurrence while on acenocumarol (n = 1. Results Mean follow up was 18 months. Baseline CHA2DS2Vasc y HAS-BLED scores were 5.6 ± 0.7 and 4.1 ± 0.3 respectively. There were no strokes or deaths. There was only one non-serious adverse event. Conclusion LAAO with ACP appears as a feasible therapeutic option for stroke prevention in patients with atrial fibrillation and failure or contraindication to acenocumarol.

  19. Limb ischemia, an alarm signal to a thromboembolic cascade - renal infarction and nephrectomy followed by surgical suppression of the left atrial appendage.

    Science.gov (United States)

    Caraşca, Cosmin; Borda, Angela; Incze, Alexandru; Caraşca, Emilian; Frigy, Attila; Suciu, HoraŢiu

    2016-01-01

    We present the case of a 55-year-old male with mild hypertension and brief episodes of paroxysmal self-limiting atrial fibrillation (AF) since 2010. Despite a small cardioembolic risk score, CHA2DS2-Vasc=1 (Congestive heart failure, Hypertension, Age=75, Diabetes melitus, prior Stroke), the patient is effectively anticoagulated using acenocumarol. In December 2014, he showed signs of plantar transitory ischemia, for which he did not address the doctor. In early January 2015, he urgently presented at the hospital with left renal pain, caused by a renal infarction, diagnosed by computed tomography (CT) angiography. Left nephrectomy was performed with pathological confirmation. He was discharged with effective anticoagulation treatment. Within the next two weeks, he suffered a transitory ischemic event and a stroke, associated with right sided hemiparesis. On admission, AF was found and converted to sinus rhythm with effective anticoagulation - international normalized ratio (INR) of 2.12. Transthoracic echocardiography detected no pathological findings. Transesophageal echocardiography showed an expended left atrial appendage (LAA) with a slow blood flow (0.2 m÷s) and spontaneous echocontrast. Considering these clinical circumstances, surgical LAA suppression was decided on as a last therapeutic resort. Postoperative evolution was favorable; the patient is still free of ischemic events, one year post-intervention. Some morphological and hemodynamic characteristics of LAA may add additional thromboembolic risk factors, not included in scores. Removing them by surgical LAA suppression may decrease the risk of cardioembolic events. Intraoperative presence of thrombus makes it an indisputable proof.

  20. Percutaneous closure of the left atrial appendage for prevention of thromboembolism in atrial fibrillation for patients with contraindication to or failure of oral anticoagulation: a single-center experience.

    Science.gov (United States)

    Faustino, Ana; Paiva, Luís; Providência, Rui; Trigo, Joana; Botelho, Ana; Costa, Marco; Leitão-Marques, António

    2013-06-01

    In non-valvular atrial fibrillation 90% of thrombi originate in the left atrial appendage (LAA). Percutaneous LAA closure has been shown to be non-inferior to warfarin for prevention of thromboembolism. To evaluate the initial experience of a single center in percutaneous LAA closure in patients with high thromboembolic risk and in whom oral anticoagulation was impractical or contraindicated or had failed. Patients with non-valvular atrial fibrillation and CHADS2 score ≥2 in whom oral anticoagulation was impractical or contraindicated or had failed underwent percutaneous LAA closure according to the standard technique. After the procedure, dual antiplatelet therapy was maintained for one month, followed by single antiplatelet therapy indefinitely. Patients were followed by clinical assessment and transthoracic and transesophageal echocardiography. The procedure was performed in 22 of the 23 selected patients (95.7%), mean age 70±9 years, CHADS2 score 3.2±0.9 and CHA2DS2-VASC score 4.7±1.4. Intraprocedural device replacement was necessary only in the first patient, due to oversizing. The following periprocedural complications were observed: one femoral pseudoaneurysm, three femoral hematomas and two minor oropharyngeal bleeds, resolved by local hemostatic measures. During a 12±8 month follow-up a mild peri-device flow and a thrombus adhering to the device, resolved under with enoxaparin therapy, were identified. The rate of transient ischemic attack (TIA)/stroke was lower than expected according to the CHADS2 score (0 vs. 6.7±2.2%). In our initial experience, this procedure proved to be a feasible, safe and effective alternative for atrial fibrillation patients in whom oral anticoagulation is not an option. Only relatively minor complications were observed, with a lower than expected TIA/stroke rate. Copyright © 2012 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  1. Activation of proteolysis by calpains and structural changes in human paroxysmal and persistent atrial fibrillation

    NARCIS (Netherlands)

    Brundel, BJJM; Ausma, J; van Gelder, IC; Van Der Want, JJL; van Gilst, WH; Crijns, HJGM; Henning, RH

    2002-01-01

    Objective: Atrial fibrillation (AF) is accompanied by electrical. structural and ion-channel protein remodeling. We tested if proteolysis by calpain and proteasome is activated during AF. and studied the relation with the remodeling processes. Methods: Right atrial appendages were obtained from pati

  2. Endoscopic Ultrasound for the Detection of Left Atrial Appendage Thrombus: A Useful Technique in Patients with Transesophageal Echocardiography Contraindication

    OpenAIRE

    2016-01-01

    Endoscopic ultrasound is a diagnostic and therapeutic technique used in specialized centers for patients that have undergone digestive procedures. This technique enables highly precise real-time imaging of the digestive tract wall and surrounding organs. Endoscopic ultrasound is also useful in patients with cardiovascular diseases such as atrial fibrillation. In patients with contraindication for transesophageal echocardiography due to high risk of esophageal bleeding or complications that ma...

  3. Left atrial appendage occlusion with the AMPLATZER Amulet device: periprocedural and early clinical/echocardiographic data from a global prospective observational study.

    Science.gov (United States)

    Landmesser, Ulf; Schmidt, Boris; Nielsen-Kudsk, Jens Erik; Lam, Simon Cheung Chi; Park, Jai-Wun; Tarantini, Giuseppe; Cruz-Gonzalez, Ignacio; Geist, Volker; Della Bella, Paolo; Colombo, Antonio; Zeus, Tobias; Omran, Heyder; Piorkowski, Christopher; Lund, Juha; Tondo, Claudio; Hildick-Smith, David

    2017-09-20

    The global, prospective AMPLATZER Amulet observational study documents real-world periprocedural, transoesophageal echocardiographic (TEE) and clinical outcomes from left atrial appendage occlusion (LAAO) using the AMPLATZER Amulet device. The aim of this report is to describe the periprocedural and early clinical/TEE results from this study. This multicentre prospective real-world registry included 1,088 patients (75±8.5 years, 64.5% male, CHA2DS2-VASc: 4.2±1.6, HAS-BLED: 3.3±1.1) with non-valvular atrial fibrillation; 82.8% of patients were considered to have an absolute or relative contraindication to long-term anticoagulation and 72.4% had had a previous major bleeding. Periprocedural results, clinical outcomes up to the first three months and the available TEE results from the first scheduled follow-up (one to three months post implant) are reported. Successful device implantation was achieved in 99.0% of patients. During the procedure and index hospitalisation, major adverse events occurred in 3.2% of patients. Patients were discharged on a single antiplatelet agent (23.0%), dual antiplatelets (54.3%) or an oral anticoagulant (18.9%). TEE follow-up 67±23 days post procedure in 673 patients showed adequate (Amulet device reports a high implant success rate and a low periprocedural complication rate in a population with a high risk of stroke and bleeding. Transoesophageal echo data confirm good closure rates during follow-up and low rates of device-associated thrombus.

  4. Dynamics of AV coupling during human atrial fibrillation: role of atrial rate.

    Science.gov (United States)

    Masè, M; Marini, M; Disertori, M; Ravelli, F

    2015-07-01

    The causal relationship between atrial and ventricular activities during human atrial fibrillation (AF) is poorly understood. This study analyzed the effects of an increase in atrial rate on the link between atrial and ventricular activities during AF. Atrial and ventricular time series were determined in 14 patients during the spontaneous acceleration of the atrial rhythm at AF onset. The dynamic relationship between atrial and ventricular activities was quantified in terms of atrioventricular (AV) coupling by AV synchrogram analysis. The technique identified n:m coupling patterns (n atrial beats in m ventricular cycles), quantifying their percentage, maximal length, and conduction ratio (= m/n). Simulations with a difference-equation AV model were performed to correlate the observed dynamics to specific atrial/nodal properties. The atrial rate increase significantly affected AV coupling and ventricular response during AF. The shortening of atrial intervals from 185 ± 32 to 165 ± 24 ms (P AV patterns with progressively decreasing m/n ratios (from conduction ratio = 0.34 ± 0.09 to 0.29 ± 0.08, P AV block and coupling instability at higher atrial rates were associated with increased ventricular interval variability (from 123 ± 52 to 133 ± 55 ms, P AV pattern transitions and coupling instability in patients were predicted, assuming the filtering of high-rate irregular atrial beats by the slow recovery of nodal excitability. These results support the role of atrial rate in determining AV coupling and ventricular response and may have implications for rate control in AF. Copyright © 2015 the American Physiological Society.

  5. Appraising the safety and efficacy profile of left atrial appendage closure in 2016 and the future clinical perspectives. Results of the EAPCI LAAC survey.

    Science.gov (United States)

    Santucci, Andrea; Byrne, Robert A; Baumbach, Andreas; Colleran, Roisin; Haude, Michael; Windecker, Stephan; Valgimigli, Marco

    2016-05-17

    The aim of this study was to determine the opinion of the scientific community regarding percutaneous left atrial appendage closure (LAAC). The main focus of the survey was on concerns and expectations regarding the safety and efficacy profile of LAAC in clinical practice and on current and future clinical perspectives. A voluntary web-based survey was distributed by the European Association of Percutaneous Coronary Interventions (EAPCI) to all individuals registered on the EuroIntervention mailing list (n=21,800). A total of 724 physicians responded to the survey, of whom 31.8% had first operator experience with LAAC. Exclusive use of the Amulet (34.4%) or WATCHMAN (30.3%) was similar, but the former was the most frequently used device in Europe. The majority of respondents (59.3%) deemed LAAC to be as effective as, but safer than oral anticoagulants (OAC) in reducing stroke risk. Periprocedural complications (40.3%) and cost (28.8%) were the major concerns. Most practitioners did not consider novel oral anticoagulants (NOACs) to be a deterrent for performing LAAC procedures. Moreover, a history of serious haemorrhage was not deemed necessary to justify LAAC for 59.8% of physicians. The results of this survey reveal a high level of confidence in percutaneous LAAC amongst surveyed interventional cardiologists, with the majority believing it to be as effective as OAC in terms of stroke prevention and safer in terms of bleeding risk.

  6. La orejuela izquierda como fuente de accidentes cerebrovasculares: cerrar (y cómo, o no cerrar (y por qué Left atrial appendage as a source of stroke: to close (and how, or not to close (and why

    Directory of Open Access Journals (Sweden)

    R. Hernández-Estefanía

    2012-04-01

    Full Text Available La orejuela izquierda se considera la principal fuente de émbolos en los accidentes cerebrovasculares que se producen en pacientes con fibrilación auricular. El tratamiento con anticoagulantes orales reduce significativamente el riesgo de accidentes embólicos cerebrales en relación con la aspirina, pero se asocia a riesgo de complicaciones hemorrágicas, por lo que no siempre son utilizados. Se ha descrito que el cierre de la orejuela izquierda reduce la tasa de accidentes tromboembólicos y en la actualidad se recomienda en pacientes en fibrilación auricular sometidos a cirugía mitral, pero la formación de émbolos en estos pacientes puede deberse a otras causas, y la implicación de la orejuela podría ser menor de la que se presupone. Además, no todos los pacientes son candidatos para la anticoagulación oral, y no todos se mantienen en un rango terapéutico adecuado, lo que podría justificar la formación de trombos auriculares. Existen diversos métodos para el cierre de la orejuela: sutura directa, exclusión epicárdica mediante grapadora o clip, u oclusión mediante los recientes dispositivos endovasculares de aplicación percutánea. Pero, según la bibliografía, la efectividad de estos métodos para ocluir completamente la orejuela, así como su seguridad y eficacia para la prevención de accidentes embólicos cerebrales, pueden presentar resultados dispares. Para aumentar la controversia, algunos métodos de cierre con sutura no revelan un claro beneficio e, incluso, en algunos se describe un aumento del riesgo de tromboembolismo. Se presenta una revisión sobre la necesidad de cierre de la orejuela izquierda para la prevención de accidentes vasculares cerebrales, así como los diversos procedimientos descritos.Left atrial appendage is considered the main source of emboli in stroke for patients with atrial fibrillation. Oral anticoagulant therapy significantly reduces the risk of cerebral embolic events as compared with

  7. Long-term follow-up after left atrial appendage occlusion with comparison of transesophageal echocardiography versus computed tomography to guide medical therapy and data about postclosure cardioversion.

    Science.gov (United States)

    Berte, Benjamin; Jost, Christine Attenhofer; Maurer, Dominik; Fäh-Gunz, Anja; Pillois, Xavier; Naegeli, Barbara; Pfyffer, Monica; Sütsch, Gabor; Scharf, Christoph

    2017-07-04

    The use of left atrial appendage (LAA) occluders in atrial fibrillation is increasing. There are few data on the comparison between transesophageal echocardiography (TEE) and computed tomography (MDCT) assessing peridevice flow and outcome of electrical cardioversion (ECV) in these patients. Single-center prospective registry from 2009 to 2015 including all LAA occluders to analyze success and complications during implantation and follow-up. Patients having ≥1 ECV were further analyzed. TEE was performed during implantation and at 6 weeks. In a subgroup of 77 patients, we compared MDCT with TEE at 6 weeks. Overall, 135 patients (69 ± 9 years; 70% male; CHA2 DS2 -VASc score: 3.6 ± 1.4; HAS-BLED score: 2.5 ± 0.6) received a LAA occluder (Watchman, n = 73; ACP-1, n = 59; Amulet, n = 3; PVI + LAA occluder, n = 91; and LAA occluder only, n = 44). Device implantation was successful in 131 (97%). Eight patients (5.9%) had major periprocedural complications (ischemic stroke/transient ischemic attacks, n = 4, tamponade, n = 2, device thrombosis, n = 2, Dressler syndrome, n = 1). The periprocedural complication rate was similar between concomitant procedure and LAA occluder only (8/91 vs. 5/44; P = 0.6). Twelve patients (9%) died (procedure-related, n = 2; 1%) during follow-up of 44 months (IQR: 43). MDCT (n = 77) at 6 weeks showed similar peridevice flow compared to TEE (TEE: 1.5 ± 1.9 mm vs. MDCT: 1.1 ± 2.2 mm, P = 0.25). Thromboembolic events occurred in 3 patients (CVA, n = 1; TIA, n = 2) during follow-up. In total, 41 ECV were performed in 26 patients (1.6 ± 0.9/patient), 13 months (IQR: 24) after implantation (<1 month: n = 8). No ECV-related clinical complications were observed. LAA occlusion is feasible with an acceptable safety profile and few events during long-term follow-up. ECV after LAA occlusion is feasible. MDCT could help to evaluate peridevice flow. © 2017 Wiley Periodicals, Inc.

  8. Device-associated thrombus formation after left atrial appendage occlusion: A systematic review of events reported with the Watchman, the Amplatzer Cardiac Plug and the Amulet.

    Science.gov (United States)

    Lempereur, Mathieu; Aminian, Adel; Freixa, Xavier; Gafoor, Sameer; Kefer, Joelle; Tzikas, Apostolos; Legrand, Victor; Saw, Jacqueline

    2017-02-01

    This study aimed to provide a systematic review of device-associated thrombosis (DAT) after left atrial appendage occlusion (LAAO) with the Watchman, Amplatzer Cardiac Plug, and Amulet devices. DAT is known as a complication of LAAO but data about its clinical impact is scarce. A systematic review of studies evaluating the incidence, treatment and clinical implications of DAT from January 2008 to September 2015 was conducted. A total of 30 studies describing DAT events were included in the analysis. The overall incidence of DAT was 3.9% (82 DAT for 2118 implanted devices). The median time from procedure to diagnosis of DAT was 1.5 months (IQR: 0-2.9). Most cases were diagnosed with transesophageal echocardiogram (TEE). The treatment consisted of low molecular weight heparin (LMWH) in 45.5% of cases, and oral anticoagulation (OAC) or other treatment modalities in 54.5%. Complete thrombus resolution was achieved in 95.0% of cases (100% with LMWH and 89.5% with OAC). Treatment duration varied greatly with a median treatment duration of 45 days (IQR: 14-135). Clinical events related to DAT consisted of neurologic events namely two transient ischemic attacks (2.4%) and four ischemic strokes (4.9%). DAT is an infrequent complication of percutaneous LAAO. It occurs mainly early after the procedure and is associated with a low rate of neurological complications. In the majority of cases, diagnosis is made during follow-up imaging with TEE. Anticoagulation treatment seems to be safe and highly effective. Further studies are needed to evaluate the optimal management of DAT. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  9. The relationship between gap junctional remodeling and human atrial fibrillation

    Institute of Scientific and Technical Information of China (English)

    李大强; 冯义柏; 张会琴

    2004-01-01

    @@ Atrial fibrillation (AF) is currently the most common cardiac tachyarrhythmia in clinical practice. AF has a tendency to become more persistent over time. Progression of an underlying disease is one explanation. Another possible explanation is electrical, structural, and gap junctional remodeling of the atrium by repetitive induction of AF.1 The expression level and distribution of it have close relation with the conduction velocity of electrical activation in the atrium. The aim of the present study was to investigate the alternations of the expression and distribution of (connexin 40, Cx 40) and (connexin 43, Cx 43) in the right atrial appendages of the patients with AF by laser confocal scanning microscopy and Western blot technique.

  10. Incomplete left atrial appendage occlusion and thrombus formation after Watchman implantation treated with anticoagulation followed by further transcatheter closure with a second-generation Amplatzer Cardiac Plug (Amulet device).

    Science.gov (United States)

    Lam, Simon Cheung Chi; Bertog, Stefan; Sievert, Horst

    2015-02-01

    We report a case of incomplete left atrial appendage (LAA) closure after Watchman device (Atritech, Boston Scientific, Natrick, MA) implantation which subsequently developed a thrombus 3 years after the initial procedure. The thrombus resolved after a short period of anticoagulation with warfarin, and the LAA was successfully occluded with a second-generation Amplatzer Cardiac Plug (Amulet device, AGA, St Jude Medical, Minneapolis, MN). Incomplete LAA closure may be associated with increased risk of thrombus formation and further closure with a second device after a course of anticoagulation may be a reasonable and feasible strategy. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.

  11. Rationale and design of a study exploring the efficacy of once-daily oral rivaroxaban (X-TRA) on the outcome of left atrial/left atrial appendage thrombus in nonvalvular atrial fibrillation or atrial flutter and a retrospective observational registry providing baseline data (CLOT-AF).

    Science.gov (United States)

    Lip, Gregory Y H; Hammerstingl, Christoph; Marin, Francisco; Cappato, Riccardo; Meng, Isabelle Ling; Kirsch, Bodo; Morandi, Eolo; van Eickels, Martin; Cohen, Ariel

    2015-04-01

    There are still many unresolved issues concerning patient outcomes and prognostic factors in patients with atrial fibrillation (AF) and left atrial/left atrial appendage (LA/LAA) thrombi. Rivaroxaban (Xarelto®), a potent and highly selective oral, direct factor Xa inhibitor, is a new therapeutic option in this setting. The planned study program will consist of a prospective interventional study (X-TRA) and a retrospective observational registry (CLOT-AF). The primary objective of the X-TRA study is to explore the efficacy of rivaroxaban in the treatment of LA/LAA thrombi in patients with nonvalvular AF or atrial flutter, scheduled to undergo cardioversion or AF ablation, in whom an LA/LAA thrombus has been found on transesophageal echocardiography (TEE) before the procedure. The primary end point is the complete LA/LAA thrombus resolution rate at 6 weeks of end of treatment confirmed by TEE. The secondary objectives are to describe categories of thrombus outcome in patients (resolved, reduced, unchanged, larger, or new) confirmed on TEE at the end of treatment (after 6 weeks of treatment), incidence of the composite of stroke and noncentral nervous system systemic embolism at the end of treatment and during follow-up, and incidence of all bleeding at the end of treatment and during follow-up. The objective of the CLOT-AF registry is to provide retrospective thrombus-related patient outcome data after standard-of-care anticoagulant treatment in patients with nonvalvular AF or atrial flutter, who have TEE-documented LA/LAA thrombi. The data will be used as a reference for the prospective X-TRA study. In conclusion, X-TRA and CLOT-AF will provide some answers to the many unresolved issues concerning patient outcomes and prognostic factors in patients with AF and LAA thrombi. Results from this study program would provide the first prospective interventional study (X-TRA) and a large international retrospective observational registry (CLOT-AF) on the prevalence and

  12. Keratin Gene Mutations in Disorders of Human Skin and its Appendages

    Science.gov (United States)

    Chamcheu, Jean Christopher; Siddiqui, Imtiaz A.; Syed, Deeba N.; Adhami, Vaqar M.; Liovic, Mirjana; Mukhtar, Hasan

    2011-01-01

    Keratins, the major structural protein of all epithelia, are a diverse group of cytoskeletal scaffolding proteins that form intermediate filament networks, providing structural support to keratinocytes that maintain the integrity of the skin. Expression of keratin genes is usually regulated by differentiation of the epidermal cells within the stratifying squamous epithelium. Amongst the 54 known functional keratin genes in humans, about 21 different genes including hair and hair follicle-specific keratins have been associated with diverse hereditary disorders. The exact phenotype of each disease mostly reflects the spatial level of expression and types of the mutated keratin genes, the positions of the mutations as well as their consequences at sub-cellular levels. The identification of specific mutations in keratin disorders is the basis of our understanding that lead to reclassification, improved diagnosis with prognostic implications, prenatal testing and genetic counseling in severe cutaneous keratin genodermatoses. A disturbance in cutaneous keratins as a result of mutation(s) in the gene(s) that encode keratin intermediate filaments (KIF) causes keratinocytes and cutaneous tissue fragility, accounting for a large number of genetic disorders in human skin and its appendages. These diseases are characterized by a loss of structural integrity in keratinocytes expressing mutated keratins in vivo, often manifested as keratinocytes fragility (cytolysis), intra-epidermal blistering, hyperkeratosis, and keratin filament aggregation in severely affected tissues. Examples include epidermolysis bullosa simplex (EBS), keratinopathic ichthyosis (KPI), pachyonychia congenital (PC), monilethrix, steatocystoma multiplex and ichthyosis bullosa of Siemens (IBS). These keratins also have been identified to have roles in cell growth, apoptosis, tissue polarity, wound healing and tissue remodeling. PMID:21176769

  13. Keratin gene mutations in disorders of human skin and its appendages.

    Science.gov (United States)

    Chamcheu, Jean Christopher; Siddiqui, Imtiaz A; Syed, Deeba N; Adhami, Vaqar M; Liovic, Mirjana; Mukhtar, Hasan

    2011-04-15

    Keratins, the major structural protein of all epithelia are a diverse group of cytoskeletal scaffolding proteins that form intermediate filament networks, providing structural support to keratinocytes that maintain the integrity of the skin. Expression of keratin genes is usually regulated by differentiation of the epidermal cells within the stratifying squamous epithelium. Amongst the 54 known functional keratin genes in humans, about 22 different genes including, the cornea, hair and hair follicle-specific keratins have been implicated in a wide range of hereditary diseases. The exact phenotype of each disease usually reflects the spatial expression level and the types of mutated keratin genes, the location of the mutations and their consequences at sub-cellular levels as well as other epigenetic and/or environmental factors. The identification of specific pathogenic mutations in keratin disorders formed the basis of our understanding that led to re-classification, improved diagnosis with prognostic implications, prenatal testing and genetic counseling in severe keratin genodermatoses. Molecular defects in cutaneous keratin genes encoding for keratin intermediate filaments (KIFs) causes keratinocytes and tissue-specific fragility, accounting for a large number of genetic disorders in human skin and its appendages. These diseases are characterized by keratinocytes fragility (cytolysis), intra-epidermal blistering, hyperkeratosis, and keratin filament aggregation in severely affected tissues. Examples include epidermolysis bullosa simplex (EBS; K5, K14), keratinopathic ichthyosis (KPI; K1, K2, K10) i.e. epidermolytic ichthyosis (EI; K1, K10) and ichthyosis bullosa of Siemens (IBS; K2), pachyonychia congenita (PC; K6a, K6b, K16, K17), epidermolytic palmo-plantar keratoderma (EPPK; K9, (K1)), monilethrix (K81, K83, K86), ectodermal dysplasia (ED; K85) and steatocystoma multiplex. These keratins also have been identified to have roles in apoptosis, cell proliferation

  14. Molecular adaptations in human atrial fibrillation : mechanisms of protein remodeling

    NARCIS (Netherlands)

    Brundel, Bianca Johanna Josephina Maria

    2000-01-01

    The main goal was to study the molecular remodeling in human atrial fibrillation. We focussed on gene expression of proteins wich influence the calcium homeostasis and action potential duration in human AF. The impact of modulation sysems like the natriuretic peptide system and the endothelin system

  15. Successful Left Atrial Appendage Occlusion with the New Generation Amulet® Device after Late-Occurring Embolization of an Amplatzer® Cardiac Plug in a Patient with Repetitive Strokes.

    Science.gov (United States)

    Schroeter, Marco R; Schillinger, Wolfgang

    2016-01-01

    The Amplatzer Cardiac Plug (ACP) is one of the most commonly used devices for percutaneous left atrial appendage (LAA) closure in order to prevent a stroke in patients with atrial fibrillation and contraindication for long-term oral anticoagulation therapy. We have previously described a patient who had experienced an embolization of the ACP device about 12 months after implantation and the device could be percutaneously retrieved. A few years later, he suffered from a posterior stroke and a stroke located in the brainstem as well as a transischemic attack (TIA). In order to protect him from further cardioembolic events a reocclusion of the LAA with the new generation of ACP device, the Amplatzer Amulet, was performed. A stable position of the device within follow-up period could be confirmed and the patient was free of additional strokes/TIA or bleeding events. This case stresses the importance of proper LAA sizing in order to prevent device embolization and notes that LAA size is not static. Moreover, it demonstrates that repeated implantation of an LAA occlusion device was still possible; one should be aware of undersizing the LAA dimensions and that the modifications of new generation LAA occlusion devices may overcome limitations of first-generation devices in order to prevent a cardioembolic stroke.

  16. Successful Left Atrial Appendage Occlusion with the New Generation Amulet® Device after Late-Occurring Embolization of an Amplatzer® Cardiac Plug in a Patient with Repetitive Strokes

    Directory of Open Access Journals (Sweden)

    Marco R. Schroeter

    2016-01-01

    Full Text Available The Amplatzer Cardiac Plug (ACP is one of the most commonly used devices for percutaneous left atrial appendage (LAA closure in order to prevent a stroke in patients with atrial fibrillation and contraindication for long-term oral anticoagulation therapy. We have previously described a patient who had experienced an embolization of the ACP device about 12 months after implantation and the device could be percutaneously retrieved. A few years later, he suffered from a posterior stroke and a stroke located in the brainstem as well as a transischemic attack (TIA. In order to protect him from further cardioembolic events a reocclusion of the LAA with the new generation of ACP device, the Amplatzer Amulet, was performed. A stable position of the device within follow-up period could be confirmed and the patient was free of additional strokes/TIA or bleeding events. This case stresses the importance of proper LAA sizing in order to prevent device embolization and notes that LAA size is not static. Moreover, it demonstrates that repeated implantation of an LAA occlusion device was still possible; one should be aware of undersizing the LAA dimensions and that the modifications of new generation LAA occlusion devices may overcome limitations of first-generation devices in order to prevent a cardioembolic stroke.

  17. Electrophysiological effects of hydrogen sulfide on human atrial fibers

    Institute of Scientific and Technical Information of China (English)

    XU Meng; WU Yu-ming; LI Qian; LIU Su; HE Rui-rong

    2011-01-01

    Background It has been reported that endogenous or exogenous hydrogen sulfide (H2S) exerts physiological effects in the vertebrate cardiovascular system.We have also demonstrated that H2S acts as an important regulator of electrophysiological properties in guinea pig papillary muscles and on pacemaker cells in sinoatrial nodes of rabbits.This study was to observe the electrophysiological effects of H2S on human atrial fibers.Methods Human atrial samples were collected during cardiac surgery.Parameters of action potential in human atrial specialized fibers were recorded using a standard intracellular microelectrode technique.Results NaHS (H2S donor) (50,100 and 200 μmol/L) decreased the amplitude of action potential (APA),maximal rate of depolarization (Vmax),velocity of diastolic (phase 4) depolarization (VDD) and rate of pacemaker firing (RPF),and shortened the duration of 90% repolarization (APD90) in a concentration-dependent manner.ATP-sensitive K+ (KATP)channel blocker glibenclamide (Gli,20 μmol/L) partially blocked the effects of NaHS (100 μmol/L) on human atrial fiber cells.The L-type Ca2+ channel agonist Bay K8644 (0.5 μmol/L) also partially blocked the effects of NaHS (100 μmol/L).An inhibitor of cystathionine y-lyase (CSE),DL-propargylglycine (PPG,200 μmol/L),increased APA,Vmax,VDD and RPF,and prolonged APD90.Conclusions H2S exerts a negative chronotropic action and accelerates the repolarization of human atrial specialized fibers,possibly as a result of increases in potassium efflux through the opening of KATP channels and a concomitant decrease in calcium influx.Endogenous H2S may be generated by CSE and act as an important regulator of electrophysiological properties in human atrial fibers.

  18. Atrial natriuretic peptide induces postprandial lipid oxidation in humans.

    NARCIS (Netherlands)

    Birkenfeld, A.L.; Budziarek, P.; Boschmann, M.; Moro, C.; Adams, F.; Franke, G.; Berlan, M.; Marques, M.A.; Sweep, F.C.; Luft, F.C.; Lafontan, M.; Jordan, J.

    2008-01-01

    OBJECTIVE: Atrial natriuretic peptide (ANP) regulates arterial blood pressure. In addition, ANP has recently been shown to promote human adipose tissue lipolysis through cGMP-mediated hormone-sensitive lipase activation. We hypothesized that ANP increases postprandial free fatty acid (FFA) availabil

  19. Basement membrane zone remodeling during appendageal development in human fetal skin. The absence of type VII collagen is associated with gelatinase-A (MMP2) activity.

    Science.gov (United States)

    Karelina, T V; Bannikov, G A; Eisen, A Z

    2000-02-01

    Epithelial cell adhesion, migration, and differentiation are controlled by interactions at the basement membrane zone (BMZ). Type VII collagen is the major collagenous component of anchoring fibrils that are essential for the attachment of the epidermis to the dermis. Gelatinase A (MMP-2) is believed to be necessary for the degradation of type VII collagen. In this study we have examined the in vivo distribution of type VII collagen and gelatinase A (Gel A) in the developing human epidermis and its appendages. At 13-15 wk of gestation a marked decrease in type VII collagen immunoreactivity was seen in the BMZ surrounding invading appendageal buds; however, type VII collagen mRNA was strongly expressed in the budding epidermal keratinocytes adjacent to the BMZ. At these stages, Gel A-positive mesenchymal-like cells were found scattered throughout the stroma with numerous Gel A-containing cells in direct contact with the developing appendageal buds. In situ zymography was used to show Gel A-activity in vivo. Gel A-mediated lysis was present at the interface between the appendageal buds and the underlying BMZ. By 20-25 wk of gestational age, immunostaining for type VII collagen protein was absent from the BMZ surrounding the distal portion of invading appendageal epithelial cords of both hair follicles and sweat glands. In contrast, type VII collagen mRNA was present in the basal keratinocytes adjacent to the BMZ surrounding the distal portion of these invading appendageal epithelial cords. At these stages Gel A-positive cells were present in the stroma directly adjacent to the distal portion of developing appendageal cords that lacked type VII collagen. In situ zymography showed zones of Gel A-mediated stromal lysis at the distal portion of developing appendageal cords. Interestingly, no differences were seen in the distribution of type IV collagen in the BMZ of both budding and resting fetal epidermis. These observations suggest that the absence of type VII collagen

  20. Atrial tissue expression of receptor for advanced glycation end-products (RAGE) and atrial fibrosis in patients with mitral valve disease.

    Science.gov (United States)

    Yang, Pil-Sung; Lee, Seung Hyun; Park, Junbeom; Kim, Tae-Hoon; Uhm, Jae-Sun; Joung, Boyoung; Lee, Moon-Hyoung; Chang, Byung-Chul; Pak, Hui-Nam

    2016-10-01

    It has been reported that receptor for advanced glycation end-products (RAGE) plays a significant role in cardiac fibrosis. Nonetheless, the precise relationship between the RAGE and atrial fibrosis has never been studied in humans. The aim of this study was to determine whether degree of atrial fibrosis was associated with atrial tissue expression of RAGE in patients with mitral valve disease (MVD). We collected human left atrial (LA) appendage tissue from 25 patients who underwent mitral valve surgery. We quantified the expression of RAGE and other protein markers by Western blotting and compared these levels with histological evaluations. RAGE expression in the LA appendage tissue was significantly correlated with atrial fibrosis (r=0.681, p=0.001). RAGE expression (regression coefficient [B] 9.49, 95% confidence interval [CI] 4.76-14.2, pRAGE expression was significantly correlated with protein expression of von Willebrand factor (r=0.659, pRAGE expression than those with no, mild, or moderate MS (p=0.013). Patients with MVD and atrial fibrillation (AF) had more severe atrial fibrosis (p=0.024) and higher RAGE expression (p=0.047) than those who remained in sinus rhythm. Atrial tissue expression of RAGE was significantly associated with atrial fibrosis, severe MS, and AF rhythm in patients with MVD. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  1. 基于三维经食管超声的3D打印模型指导左心耳封堵的可行性研究%Guidance of three-dimensional printing model of left atrial appendage derived from transesophageal echocardiography for left atrial appendage closure

    Institute of Scientific and Technical Information of China (English)

    宋宏宁; 周青; 邓倾; 陈金玲; 张兰; 何发智; 潘一腾; 刘育; 郭瑞强

    2016-01-01

    Objective To investigate the feasibility of three dimensional printing left atrial appendage(LAA) models from three dimensional transesophageal echocardiography (3D-TEE) volume-rendered data and its value for guiding the placement of LAA occlusion device.Methods Ten patients with non-valvular atrial fibrillation (AF) were underwent TEE before LAA occlusion.3D full volume data and routine two dimensional images of the LAA were acquired.The 3D-TEE data were post-processed by grey values inverted imaging and threshold segmentation to create volume rendered images of the LAA in STL format.The cardiac chamber model and the cardiac wall model of the LAA were printed out by 3D printer for the LAA morphology evaluation and measurement.Preoperative rehearsal was carried out on the printed 3D LAA models.Results In all the patients,3D-TEE full volume data of the LAA were successfully reprocessed and printed out.In terms of the LAA morphology classification based on cardiac chamber models there were 5 chicken wing,3 windsock and 2 cauliflower.And there were 4 single-lobed,3 bi-lobed and 3 multi-lobed.The maximal ostium diameter and the depth of the main anchoring lobe were (20.30 ±3.53)mm and (28.26 ± 5.51)mm respectively,which were concordant well with the measurements of 2D-TEE and CT.The LAmbre and the Lefort occlusion device could be implanted into the 3D LAA models for occlusion planning before the procedure.Occlusion success rate was 100%.Conclusions 3D-TEE full volume data is feasible and capable of creating LAA 3D models.3D models of LAA derived from 3D-TEE have promising value in guiding the LAA occlusion procedure.%目的 探讨应用三维经食管超声(3D-TEE)心腔容积成像进行左心耳3D打印的技术可行性及该技术对左心耳封堵的指导价值.方法 10例因非瓣膜性心房颤动进行经导管左心耳封堵患者,术前行经食管超声心动图检查,采集左心耳二维图像及三维容积图像.对三维DICOM数据进行后处理

  2. Chymase-dependent generation of angiotensin II from angiotensin-(1-12 in human atrial tissue.

    Directory of Open Access Journals (Sweden)

    Sarfaraz Ahmad

    Full Text Available Since angiotensin-(1-12 [Ang-(1-12] is a non-renin dependent alternate precursor for the generation of cardiac Ang peptides in rat tissue, we investigated the metabolism of Ang-(1-12 by plasma membranes (PM isolated from human atrial appendage tissue from nine patients undergoing cardiac surgery for primary control of atrial fibrillation (MAZE surgical procedure. PM was incubated with highly purified ¹²⁵I-Ang-(1-12 at 37°C for 1 h with or without renin-angiotensin system (RAS inhibitors [lisinopril for angiotensin converting enzyme (ACE, SCH39370 for neprilysin (NEP, MLN-4760 for ACE2 and chymostatin for chymase; 50 µM each]. ¹²⁵I-Ang peptide fractions were identified by HPLC coupled to an inline γ-detector. In the absence of all RAS inhibitor, ¹²⁵I-Ang-(1-12 was converted into Ang I (2±2%, Ang II (69±21%, Ang-(1-7 (5±2%, and Ang-(1-4 (2±1%. In the absence of all RAS inhibitor, only 22±10% of ¹²⁵I-Ang-(1-12 was unmetabolized, whereas, in the presence of the all RAS inhibitors, 98±7% of ¹²⁵I-Ang-(1-12 remained intact. The relative contribution of selective inhibition of ACE and chymase enzyme showed that ¹²⁵I-Ang-(1-12 was primarily converted into Ang II (65±18% by chymase while its hydrolysis into Ang II by ACE was significantly lower or undetectable. The activity of individual enzyme was calculated based on the amount of Ang II formation. These results showed very high chymase-mediated Ang II formation (28±3.1 fmol × min⁻¹ × mg⁻¹, n = 9 from ¹²⁵I-Ang-(1-12 and very low or undetectable Ang II formation by ACE (1.1±0.2 fmol×min⁻¹ × mg⁻¹. Paralleling these findings, these tissues showed significant content of chymase protein that by immunocytochemistry were primarily localized in atrial cardiac myocytes. In conclusion, we demonstrate for the first time in human cardiac tissue a dominant role of cardiac chymase in the formation of Ang II from Ang-(1-12.

  3. Late Sodium Current in Human Atrial Cardiomyocytes from Patients in Sinus Rhythm and Atrial Fibrillation.

    Science.gov (United States)

    Poulet, Claire; Wettwer, Erich; Grunnet, Morten; Jespersen, Thomas; Fabritz, Larissa; Matschke, Klaus; Knaut, Michael; Ravens, Ursula

    2015-01-01

    Slowly inactivating Na+ channels conducting "late" Na+ current (INa,late) contribute to ventricular arrhythmogenesis under pathological conditions. INa,late was also reported to play a role in chronic atrial fibrillation (AF). The objective of this study was to investigate INa,late in human right atrial cardiomyocytes as a putative drug target for treatment of AF. To activate Na+ channels, cardiomyocytes from transgenic mice which exhibit INa,late (ΔKPQ), and right atrial cardiomyocytes from patients in sinus rhythm (SR) and AF were voltage clamped at room temperature by 250-ms long test pulses to -30 mV from a holding potential of -80 mV with a 100-ms pre-pulse to -110 mV (protocol I). INa,late at -30 mV was not discernible as deviation from the extrapolated straight line IV-curve between -110 mV and -80 mV in human atrial cells. Therefore, tetrodotoxin (TTX, 10 μM) was used to define persistent inward current after 250 ms at -30 mV as INa,late. TTX-sensitive current was 0.27±0.06 pA/pF in ventricular cardiomyocytes from ΔKPQ mice, and amounted to 0.04±0.01 pA/pF and 0.09±0.02 pA/pF in SR and AF human atrial cardiomyocytes, respectively. With protocol II (holding potential -120 mV, pre-pulse to -80 mV) TTX-sensitive INa,late was always larger than with protocol I. Ranolazine (30 μM) reduced INa,late by 0.02±0.02 pA/pF in SR and 0.09±0.02 pA/pF in AF cells. At physiological temperature (37°C), however, INa,late became insignificant. Plateau phase and upstroke velocity of action potentials (APs) recorded with sharp microelectrodes in intact human trabeculae were more sensitive to ranolazine in AF than in SR preparations. Sodium channel subunits expression measured with qPCR was high for SCN5A with no difference between SR and AF. Expression of SCN8A and SCN10A was low in general, and lower in AF than in SR. In conclusion, We confirm for the first time a TTX-sensitive current (INa,late) in right atrial cardiomyocytes from SR and AF patients at room

  4. Late Sodium Current in Human Atrial Cardiomyocytes from Patients in Sinus Rhythm and Atrial Fibrillation.

    Directory of Open Access Journals (Sweden)

    Claire Poulet

    Full Text Available Slowly inactivating Na+ channels conducting "late" Na+ current (INa,late contribute to ventricular arrhythmogenesis under pathological conditions. INa,late was also reported to play a role in chronic atrial fibrillation (AF. The objective of this study was to investigate INa,late in human right atrial cardiomyocytes as a putative drug target for treatment of AF. To activate Na+ channels, cardiomyocytes from transgenic mice which exhibit INa,late (ΔKPQ, and right atrial cardiomyocytes from patients in sinus rhythm (SR and AF were voltage clamped at room temperature by 250-ms long test pulses to -30 mV from a holding potential of -80 mV with a 100-ms pre-pulse to -110 mV (protocol I. INa,late at -30 mV was not discernible as deviation from the extrapolated straight line IV-curve between -110 mV and -80 mV in human atrial cells. Therefore, tetrodotoxin (TTX, 10 μM was used to define persistent inward current after 250 ms at -30 mV as INa,late. TTX-sensitive current was 0.27±0.06 pA/pF in ventricular cardiomyocytes from ΔKPQ mice, and amounted to 0.04±0.01 pA/pF and 0.09±0.02 pA/pF in SR and AF human atrial cardiomyocytes, respectively. With protocol II (holding potential -120 mV, pre-pulse to -80 mV TTX-sensitive INa,late was always larger than with protocol I. Ranolazine (30 μM reduced INa,late by 0.02±0.02 pA/pF in SR and 0.09±0.02 pA/pF in AF cells. At physiological temperature (37°C, however, INa,late became insignificant. Plateau phase and upstroke velocity of action potentials (APs recorded with sharp microelectrodes in intact human trabeculae were more sensitive to ranolazine in AF than in SR preparations. Sodium channel subunits expression measured with qPCR was high for SCN5A with no difference between SR and AF. Expression of SCN8A and SCN10A was low in general, and lower in AF than in SR. In conclusion, We confirm for the first time a TTX-sensitive current (INa,late in right atrial cardiomyocytes from SR and AF patients at room

  5. Late Sodium Current in Human Atrial Cardiomyocytes from Patients in Sinus Rhythm and Atrial Fibrillation

    DEFF Research Database (Denmark)

    Poulet, Claire; Wettwer, Erich; Grunnet, Morten

    2015-01-01

    -pulse to -80 mV) TTX-sensitive INa,late was always larger than with protocol I. Ranolazine (30 μM) reduced INa,late by 0.02±0.02 pA/pF in SR and 0.09±0.02 pA/pF in AF cells. At physiological temperature (37°C), however, INa,late became insignificant. Plateau phase and upstroke velocity of action potentials...... to -30 mV from a holding potential of -80 mV with a 100-ms pre-pulse to -110 mV (protocol I). INa,late at -30 mV was not discernible as deviation from the extrapolated straight line IV-curve between -110 mV and -80 mV in human atrial cells. Therefore, tetrodotoxin (TTX, 10 μM) was used to define...... persistent inward current after 250 ms at -30 mV as INa,late. TTX-sensitive current was 0.27±0.06 pA/pF in ventricular cardiomyocytes from ΔKPQ mice, and amounted to 0.04±0.01 pA/pF and 0.09±0.02 pA/pF in SR and AF human atrial cardiomyocytes, respectively. With protocol II (holding potential -120 mV, pre...

  6. Analysis of atrial fibrillatory rate during spontaneous episodes of atrial fibrillation in humans using implantable loop recorder electrocardiogram.

    Science.gov (United States)

    Platonov, Pyotr G; Stridh, Martin; de Melis, Mirko; Urban, Lubos; Carlson, Jonas; Corbucci, Giorgio; Holmqvist, Fredrik

    2012-01-01

    Atrial fibrillatory rate (AFR) can predict outcome of interventions for atrial fibrillation (AF); however, AFR behavior at AF onset in humans is poorly described. We studied AFR during spontaneous AF episodes in patients with lone paroxysmal AF who received implantable loop recorders and had AF episodes of 1 hour or more recorded (n = 4). Mean AFR per minute was assessed from continuous implantable loop recorder electrocardiogram using spatiotemporal QRST cancellation and time-frequency analysis. Atrial fibrillatory rate increased from 290 ± 20 to 326 ± 39 fibrillations per minute during the first 3 hours (P<.05) and reached plateau then. Atrial fibrillatory rate beyond the initial 3 hours can, therefore, be considered stable and may be evaluated for prediction of intervention effect.

  7. BM-12CEREBRAL INFARCTION SECONDARY TO PULMONARY VEIN COMPRESSION AND LEFT ATRIAL APPENDAGE TUMOR INFILTRATION AS THE PRESENTING SIGN OF METASTATIC SQUAMOUS CELL CARCINOMA OF THE BASE OF THE TONGUE

    Science.gov (United States)

    Dredla, Brynn; Siegel, Jason; Jaeckle, Kurt

    2014-01-01

    BACKGROUND: Squamous cell carcinoma of the tongue has been documented to metastasize to the lungs and rarely involve the heart. The majority of documented cases of cardiac metastases are from postmortem analysis. Cases of sudden death, syncope, and dyspnea have been reported. However, stroke and tumor embolization to the brain as the initial clinical presentation has not been documented in the English literature. METHODS: Case Report. RESULTS: This case addresses a 61-year-old male with Stage IVA squamous cell carcinoma of the left tongue base, believed to be in remission after systemic chemotherapy and local radiation, who presented with acute cerebral infarctions involving multiple vascular territories. Cardiac CT obtained during stroke etiology evaluation displayed metastatic disease compressing the pulmonary vein resulting in virtual pulmonary vein thrombus. Transthoracic echocardiogram was negative for cardiac valvular pathology. Anticoagulation was initiated. Twelve days later he returned with recurrent strokes and suspected tumor embolization to the brain. Imaging displayed left atrial appendage structural abnormality highly suggestive of tumor infiltration. CONCLUSION: Cardiac metastases are rare and non-myxomatous tumor embolization to the brain even rarer especially in the setting of cerebral infarction due to pulmonary vein thrombus. Here we describe a case of multiple acute cerebral infarctions appearing from a proximal source refractory to anticoagulation. Thromboembolism from the pulmonary vein and tumor embolization from cardiac metastases are the likely mechanisms for his clinical presentation and radiographic findings. This case demonstrates the complexity of multiple stroke etiologies in one patient and the importance of cardiac imaging in stroke evaluation, particularly in the setting of a patient with a history of cancer.

  8. Application of Mimics three-dimensional imaging in percutaneous left atrial appendage closure with Watchman system%Mimics三维成像在经皮左心耳封堵术中的应用

    Institute of Scientific and Technical Information of China (English)

    杨栋; 徐曌; 张逸群; 罗艳红; 张菊红; 王益钢; Brendan Gunalingam; 张邢炜

    2015-01-01

    目的 使用Mimics三维成像技术重建心房颤动患者左心耳三维结构,初步评估经皮左心耳封堵术(Watchman系统)手术风险,指导封堵器选择及放置.方法 入选2014年5-12月在杭州师范大学附属医院心内科行左心耳封堵术患者10例,年龄40 ~ 85岁的心房颤动患者10例,均不愿长期口服抗凝药物或口服抗凝药物有禁忌证,具有左心耳封堵适应证,且自愿参加本试验.术前行Mimics左心耳三维重建,结合术中经食道超声心动图(TEE)及造影结果,选择Watchman左心耳封堵器尺寸及放置位置,置入封堵器至左心耳颈部.结果 入选心房颤动患者年龄为(66.3±11.9)岁,其中9例为非瓣膜病心房颤动患者,CHADS2-VAS评分(3.2±1.7)分,HAS-BLED评分(2.7±1.6)分;1例为瓣膜病心房颤动患者(曾行二尖瓣成形术,缺乏外科换瓣手术的适应证).10例患者均成功置入Watchman左心耳封堵系统,术后行左心耳造影及TEE均未发现封堵伞处血流渗漏.围手术期及术后1个月随访无出血及栓塞等并发症发生.结论 术前使用Mimics三维成像技术重建心房颤动患者左心耳三维结构,为左心耳封堵术封堵器置入提供重要的参考依据.%Objective The three-dimensional (3D) structure of left atrial appendage (LAA) in atrial fibrillation patients were reconstructed by Mimics 3D imaging system,aiming at guiding for selection of both the size and location of the closure devices and making preliminary risk assessment of LAA closure with Watchman system.Methods Inclusion criteria were:ten voluntary patients with both atrial fibrillation and indication for LAA closure aging from 40 to 85 years old with contraindication for oral anticoagulants or unwillingness to take long-term oral anticoagulation therapy from May to December 2014.3D reconstruction of LAA was preoperatively made by Mimics 3D imaging system.With the Mimics 3D reconstruction model and the results of both transesophageal

  9. Rationale and design of a global registry to evaluate real-world clinical outcomes in patients with atrial fibrillation and high risk of stroke treated with left atrial appendage occlusion using the AMPLATZER amulet device-Perspective of available/ongoing registries of catheter-based LAA occlusion.

    Science.gov (United States)

    Hildick-Smith, David; Diener, Hans-Christoph; Schmidt, Boris; Paul, Vincent; Settergren, Magnus; Teiger, Emmanuel; Camm, John; Tondo, Claudio; Landmesser, Ulf

    2017-09-01

    To describe the rationale and design of a global prospective registry on catheter-based left atrial appendage (LAA) occlusion using the second generation AMPLATZER Amulet LAA occlusion device and to provide a comprehensive perspective on available/ongoing registries for catheter-based LAA occlusion. Given the increasing clinical application of catheter-based LAA occlusion, there is an important need for prospective real-world clinical data regarding this cardiac intervention. The Global Amplatzer Amulet LAA registry aims to provide prospective real-world data from an all-comer population of atrial fibrillation (AF) patients undergoing catheter-based LAA occlusion for stroke prevention. This observational, prospective, multicenter registry will provide peri-procedural and long-term clinical outcome data for catheter-based LAA occlusion using a second generation LAA occlusion device. The global registry will enroll 1,000 patients at up to 75 institutions. Patients will be followed for 2 years after implantation. Primary endpoints will report procedural and long-term data on ischemic stroke, systemic embolism, cardiovascular death and major bleeding. The study will involve independent event adjudication and echocardiographic core laboratory evaluation. Long-term follow-up data are expected in 2018. The Global Amplatzer Amulet LAA registry will collect safety and efficacy information on catheter-based LAA occlusion. Characteristics of available and ongoing catheter-based LAA occlusion registries are described. There is an important need for prospective real-world clinical data of catheter-based LAA occlusion given the increasing application of this intervention. The present global real-world registry will expand our knowledge on peri-procedural and long-term outcome of catheter-based LAA occlusion using a second generation occlusion device. © 2017 Wiley Periodicals, Inc.

  10. Identification and purification of human induced pluripotent stem cell-derived atrial-like cardiomyocytes based on sarcolipin expression.

    Directory of Open Access Journals (Sweden)

    Rebecca Josowitz

    Full Text Available The use of human stem cell-derived cardiomyocytes to study atrial biology and disease has been restricted by the lack of a reliable method for stem cell-derived atrial cell labeling and purification. The goal of this study was to generate an atrial-specific reporter construct to identify and purify human stem cell-derived atrial-like cardiomyocytes. We have created a bacterial artificial chromosome (BAC reporter construct in which fluorescence is driven by expression of the atrial-specific gene sarcolipin (SLN. When purified using flow cytometry, cells with high fluorescence specifically express atrial genes and display functional calcium handling and electrophysiological properties consistent with atrial cardiomyocytes. Our data indicate that SLN can be used as a marker to successfully monitor and isolate hiPSC-derived atrial-like cardiomyocytes. These purified cells may find many applications, including in the study of atrial-specific pathologies and chamber-specific lineage development.

  11. Isolated Atrial Amyloidosis in Patients with Various Types of Atrial Fibrillation.

    Science.gov (United States)

    Sukhacheva, T V; Eremeeva, M V; Ibragimova, A G; Vaskovskii, V A; Serov, R A; Revishvili, A Sh

    2016-04-01

    The myocardium of the right and left atrial appendages (auricles) in patients with paroxysmal, persistent, and permanent forms of atrial fibrillation was examined by histological methods and electron microscopy. Isolated atrial amyloidosis was detected in the left (50.0-56.3% patients) and in the right (45.0-55.6% patients) atrial appendages. In all cases, immunohistochemistry revealed atrial natriuretic peptide in fibrillary amyloid deposits. Ultrastructurally, amyloid masses formed clusters of myofibrils 8-10 nm in diameter. They were chaotically located in the extracellular space along the sarcolemma as well as in membrane invaginations, dilated tubules of cardiomyocyte T-tubular system, and vascular walls. Amyloidosis was predominantly observed in women; its degree positively correlated with age of patients and duration of atrial fibrillation but negatively correlated with atrial fibrosis. The study revealed positive (in permanent atrial fibrillation) and negative (in paroxysmal atrial fibrillation) correlation of amyloidosis with myofibril content in atrial cardiomyocytes.

  12. Nodal recovery, dual pathway physiology, and concealed conduction determine complex AV dynamics in human atrial tachyarrhythmias.

    Science.gov (United States)

    Masè, Michela; Glass, Leon; Disertori, Marcello; Ravelli, Flavia

    2012-11-15

    The genesis of complex ventricular rhythms during atrial tachyarrhythmias in humans is not fully understood. To clarify the dynamics of atrioventricular (AV) conduction in response to a regular high-rate atrial activation, 29 episodes of spontaneous or pacing-induced atrial flutter (AFL), covering a wide range of atrial rates (cycle lengths from 145 to 270 ms), were analyzed in 10 patients. AV patterns were identified by applying firing sequence and surrogate data analysis to atrial and ventricular activation series, whereas modular simulation with a difference-equation AV node model was used to correlate the patterns with specific nodal properties. AV node response at high atrial rate was characterized by 1) AV patterns of decreasing conduction ratios at the shortening of atrial cycle length (from 236.3 ± 32.4 to 172.6 ± 17.8 ms) according to a Farey sequence ordering (conduction ratio from 0.34 ± 0.12 to 0.23 ± 0.06; P AV block patterns occurring during regular atrial tachyarrhythmias. The characterization of AV nodal function during different AFL forms constitutes an intermediate step toward the understanding of complex ventricular rhythms during atrial fibrillation.

  13. Application of CHADS2 score in prediction of left atrial/left atrial appendage thrombus in patients with nonvalvular atrial fibrillation%应用CHADS2评分预测非瓣膜性心房颤动患者左心房/左心耳血栓

    Institute of Scientific and Technical Information of China (English)

    毕文静; 李颖; 任卫东; 杨军; 孙菲菲

    2013-01-01

    Objective To explore the correlation between CHADS2 score and prevalence of left atrial/left atrial appendage (LA/LAA) thrombus in patients with nonvalvular atrial fibrillation (NVAF). Methods Clinical data of 187 NVAF patients were analyzed, and CHADS2 score were derived. The patients were divided into thrombus group and non-thrombus group based on the results of TEE. The association between CHADS2 score and prevalence of LA/LAA thrombus, and frequency differences of CHADS2 factors between thrombus group and non-thrombus groups were analyzed. Results The prevalence of LA/LAA thrombus was 14. 44% (27/187) , and the detection rate of thrombus was 2. 13% (1/47), 13. 41% (11/82), 24.24% (8/33), 29.41% (5/17), 16.67% (1/6), 50.00% (1/2) in patients with CHADS2 score of 0, 1, 2, 3, 4 and 5, respectively. The prevalence of LA/LAA thrombus showed a trend of increase with the raising of CHADS2 score, and both of them had significant correlation (P = 0. 001). In thrombus group, 37. 04% (10/27) patients had history of congestive heart failure, higher than those in non-thrombus group (x2 =5. 92, P=0. 02). Of other factors of CHADS2 score, there was no significant difference between thrombus group and non-thrombus groups (all P>0. 05). Conclusion In NVAF patients, the prevalence of LA/LAA thrombus increases significantly with higher CHADS2 scores. Congestive heart failure is the only independent associated risk factor of LA/LAA thrombus.%目的 探讨非瓣膜性心房颤动(简称房颤)患者CHADS2评分与其左心房/左心耳(LA/LAA)血栓患病率间的关系.方法 回顾性分析187例非瓣膜性房颤患者资料,对其进行CHADS2评分,根据TEE检查结果分为血栓组及非血栓组,分析CHADS2评分与LA/LAA血栓患病率间的关系及各因子在两组中的差异.结果 187例中,27例(27/187,14.44%)确诊为LA/LAA血栓,其中0分者1例(1/47,2.13%),1分者11例(11/82,13.41%),2分者8例(8/33,24.24%),3分者5例(5/17,29.41%),4分者1例(1

  14. Immunohistochemical expression of atrial natriuretic peptide (ANP) in the conducting system and internodal atrial myocardium of human hearts.

    Science.gov (United States)

    Benvenuti, L A; Aiello, V D; Higuchi, M de L; Palomino, S A

    1997-06-01

    Expression and distribution of atrial natriuretic peptide (ANP) were studied immunohistochemically in the conducting system and internodal atrial myocardium of 5 adult human hearts. Myocytes from the sinus node and compact atrioventricular node were usually ANP-negative; only a very few cells exhibited ANP immunoreactivity. These ANP-positive myocytes were small and did not appear to be trapped working atrial myocytes which are larger than nodal cells. The transitional cell zones of the sinus node and the atrioventricular node were composed of bundles of ANP-positive myocytes, intermingled with non-reactive myocytes. The internodal atrial myocardium exhibited a comparable intensity of myocyte staining in each case examined. Thus, morphologically distinct connecting pathways between the sinus node and the atrioventricular node with regard to myocyte ANP immunoreactivity could not be demonstrated, reinforcing the notion that they actually do not exist. The penetrating bundle, branching bundle and bundle branches were usually composed of ANP-negative myocytes although some ANP-positive myocytes were observed in the branching bundle and bundle branches in 4 cases. Myocytes from the ventricular conducting tissue presenting ANP immunoreactivity have been designated Purkinje fibers and have been found in several mammalian species.

  15. Effects of Persistent Atrial Fibrillation-Induced Electrical Remodeling on Atrial Electro-Mechanics – Insights from a 3D Model of the Human Atria

    Science.gov (United States)

    Adeniran, Ismail; MacIver, David H.; Garratt, Clifford J.; Ye, Jianqiao; Hancox, Jules C.; Zhang, Henggui

    2015-01-01

    Aims Atrial stunning, a loss of atrial mechanical contraction, can occur following a successful cardioversion. It is hypothesized that persistent atrial fibrillation-induced electrical remodeling (AFER) on atrial electrophysiology may be responsible for such impaired atrial mechanics. This simulation study aimed to investigate the effects of AFER on atrial electro-mechanics. Methods and Results A 3D electromechanical model of the human atria was developed to investigate the effects of AFER on atrial electro-mechanics. Simulations were carried out in 3 conditions for 4 states: (i) the control condition, representing the normal tissue (state 1) and the tissue 2–3 months after cardioversion (state 2) when the atrial tissue recovers its electrophysiological properties after completion of reverse electrophysiological remodelling; (ii) AFER-SR condition for AF-remodeled tissue with normal sinus rhythm (SR) (state 3); and (iii) AFER-AF condition for AF-remodeled tissue with re-entrant excitation waves (state 4). Our results indicate that at the cellular level, AFER (states 3 & 4) abbreviated action potentials and reduced the Ca2+ content in the sarcoplasmic reticulum, resulting in a reduced amplitude of the intracellular Ca2+ transient leading to decreased cell active force and cell shortening as compared to the control condition (states 1 & 2). Consequently at the whole organ level, atrial contraction in AFER-SR condition (state 3) was dramatically reduced. In the AFER-AF condition (state 4) atrial contraction was almost abolished. Conclusions This study provides novel insights into understanding atrial electro-mechanics illustrating that AFER impairs atrial contraction due to reduced intracellular Ca2+ transients. PMID:26606047

  16. Effect of microRNA-101 on atrial fibrosis in human chronic atrial fibrillation%微小RNA鄄101在心房颤动心房纤维化中的作用

    Institute of Scientific and Technical Information of China (English)

    蒋智渊; 钟国强; 肖飞; 何艳; 洪钰杰

    2015-01-01

    目的:探讨微小RNA-101(miRNA-101)在心房颤动心房纤维化中的作用。方法:59例开胸手术患者(心脏瓣膜病47例,先天性心脏病12例),分为房颤组30例、窦律组29例。qPCR及锁定核苷酸原位杂交技术检测两组右心耳 miRNA-101表达;qPCR 检测两组右心耳转化生长因子βⅠ型受体( TGFβRⅠ)、Ⅰ型胶原(COL1)mRNA 表达;免疫印迹法检测两组右心耳 TGFβRI、COL1蛋白表达;Masson 染色观察两组右心耳胶原的沉积。结果:房颤组右心耳 miRNA-101表达明显低于窦律组(P <0.05),原位杂交显示miRNA-101主要分布于心房结缔组织,房颤组 miRNA-101表达较窦律组下降24.9%;房颤组 TGFβRⅠmRNA表达与窦律组无明显差异(P >0.05),但蛋白表达明显高于窦律组(P <0.05);COL1mRNA及蛋白表达均明显高于窦律组(P <0.05);房颤组右心耳胶原沉积明显多于窦律组(P <0.05)。结论:miRNA-101下调在心房颤动心房纤维化过程中起重要作用,其可能通过调控TGFβRⅠ而参与心房纤维化。%Objective To investigate the effect of microRNA-101 (miRNA-101) on atrial fibrosis in human chronic atrial fibrillation (AF). Methods Right atrial appendages were obtained from 59 patients (30 with AF) undergoing cardiac surgery, including 47 patients with valve heart disease and 12 patients with congenital heart disease. The expression of miRNA-101 was determined by quantitative real-time PCR in the right atrial appendages of patients with and without AF. The cell-specific localization of miRNA-101 was detected by in situ hybridization assay. The mRNA and protein expression levels of transforming growth factor β typeⅠreceptor (TGFβRⅠ) and collagen type I (COL1) were determined by quantitative real-time PCR and Western-blot assay, respectively. Collagen in the right atrial appendages was observed by Masson staining assay. Results The expression

  17. Difference of Sodium Currents between Pediatric and Adult Human Atrial Myocytes: Evidence for Developmental Changes of Sodium Channels

    Directory of Open Access Journals (Sweden)

    Benzhi Cai, Xiaoqin Mu, Dongmei Gong, Shulin Jiang, Jianping Li, Qingxin Meng, Yunlong Bai, Yanju Liu, Xinyue Wang, Xueying Tan, Baofeng Yang, Yanjie Lu

    2011-01-01

    Full Text Available Voltage-gated calcium currents and potassium currents were shown to undergo developmental changes in postnatal human and animal cardiomocytes. However, so far, there is no evidence whether sodium currents also presented the developmental changes in postnatal human atrial cells. The aim of this study was to observe age-related changes of sodium currents between pediatric and adult atrial myocytes. Human atrial myocytes were acutely isolated and the whole-cell patch clamp technique was used to record sodium currents isolated from pediatric and adult atrial cardiomocytes. The peak amplitude of sodium currents recorded in adult atrial cells was significantly larger than that in pediatric atrial myocytes. However, there was no significant difference of the activation voltage for peak sodium currents between two kinds of atrial myocytes. The time constants for the activation and inactivation of sodium currents were smaller in adult atria than pediatric atria. The further study revealed that the voltage-dependent inactivation of sodium currents were more slow in adult atrial cardiomyocytes than pediatric atrial cells. A significant difference was also observed in the recovery process of sodium channel from inactivation. In summary, a few significant differences were demonstrated in sodium currents characteristics between pediatric and adult atrial myocytes, which indicates that sodium currents in human atria also undergo developmental changes.

  18. Effects of NIP-141 on K currents in human atrial myocytes.

    Science.gov (United States)

    Seki, Akiko; Hagiwara, Nobuhisa; Kasanuki, Hiroshi

    2002-01-01

    A novel benzopyran derivative, NIP-141, effectively terminates experimental atrial fibrillation in canine hearts by prolonging atrial refractoriness. However, the effects of this drug on human atrial myocytes are unknown. This experiment evaluated the effects of NIP-141 on K currents in isolated human atrial myocytes using a whole-cell voltage-clamp method. NIP-141 inhibited the transient outward current (I(to)) and the ultra-rapid delayed rectifier K current (I(Kur)), each in a dose-dependent manner, with half-maximal inhibition concentrations of 16.3 microM and 5.3 microM, respectively (n = 5). NIP-141 inhibited both K currents in a voltage- and use-independent fashion, and it preferentially blocked them in the open state and dissociated rapidly from the channel. Because both K currents contribute significantly to the repolarization of the atrial action potential, these findings suggest that NIP-141 may terminate atrial fibrillation by prolonging action potential duration.

  19. Hypertension is associated with preamyloid oligomers in human atrium: a missing link in atrial pathophysiology?

    Science.gov (United States)

    Sidorova, Tatiana N; Mace, Lisa C; Wells, K Sam; Yermalitskaya, Liudmila V; Su, Pei-Fang; Shyr, Yu; Atkinson, James B; Fogo, Agnes B; Prinsen, Joseph K; Byrne, John G; Petracek, Michael R; Greelish, James P; Hoff, Steven J; Ball, Stephen K; Glabe, Charles G; Brown, Nancy J; Barnett, Joey V; Murray, Katherine T

    2014-12-02

    Increasing evidence indicates that proteotoxicity plays a pathophysiologic role in experimental and human cardiomyopathy. In organ-specific amyloidoses, soluble protein oligomers are the primary cytotoxic species in the process of protein aggregation. While isolated atrial amyloidosis can develop with aging, the presence of preamyloid oligomers (PAOs) in atrial tissue has not been previously investigated. Atrial samples were collected during elective cardiac surgery in patients without a history of atrial arrhythmias, congestive heart failure, cardiomyopathy, or amyloidosis. Immunohistochemistry was performed for PAOs using a conformation-specific antibody, as well as for candidate proteins identified previously in isolated atrial amyloidosis. Using a myocardium-specific marker, the fraction of myocardium colocalizing with PAOs (PAO burden) was quantified (green/red ratio). Atrial samples were obtained from 92 patients, with a mean age of 61.7±13.8 years. Most patients (62%) were male, 23% had diabetes, 72% had hypertension, and 42% had coronary artery disease. A majority (n=62) underwent aortic valve replacement, with fewer undergoing coronary artery bypass grafting (n=34) or mitral valve replacement/repair (n=24). Immunostaining detected intracellular PAOs in a majority of atrial samples, with a heterogeneous distribution throughout the myocardium. Mean green/red ratio value for the samples was 0.11±0.1 (range 0.03 to 0.77), with a value ≥0.05 in 74 patients. Atrial natriuretic peptide colocalized with PAOs in myocardium, whereas transthyretin was located in the interstitium. Adjusting for multiple covariates, PAO burden was independently associated with the presence of hypertension. PAOs are frequently detected in human atrium, where their presence is associated with clinical hypertension. © 2014 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  20. Molecular mechanisms of remodeling in human atrial fibrillation

    NARCIS (Netherlands)

    Brundel, BJJM; Henning, RH; Kampinga, HH; Van Gelder, IC; Crijns, HJGM

    2002-01-01

    An important acknowledgement of the last several years is that atrial fibrillation (AF) modifies the electrical properties of the atrium in a way that promotes its occurrence and maintenance. This arrhythmogenic electrophysiological remodeling is well established, but can not explain by itself that

  1. T wave alternans during exercise and atrial pacing in humans

    Science.gov (United States)

    Hohnloser, S. H.; Klingenheben, T.; Zabel, M.; Li, Y. G.; Albrecht, P.; Cohen, R. J.

    1997-01-01

    INTRODUCTION: Evidence is accumulating that microvolt T wave alternans (TWA) is a marker of increased risk for ventricular tachyarrhythmias. Initially, atrial pacing was used to elevate heart rate and elicit TWA. More recently, a noninvasive approach has been developed that elevates heart rate using exercise. METHODS AND RESULTS: In 30 consecutive patients with a history of ventricular tachyarrhythmias, the spectral method was used to detect TWA during both atrial pacing and submaximal exercise testing. The concordance rate for the presence or absence of TWA using the two measurement methods was 84%. There was a patient-specific heart rate threshold for the detection of TWA that averaged 100 +/- 14 beats/min during exercise compared with 97 +/- 9 beats/min during right atrial pacing (P = NS). Beyond this threshold, there was a significant and comparable increase in level of TWA with decreasing pacing cycle length and increasing exercise heart rates. CONCLUSIONS: The present study is the first to demonstrate that microvolt TWA can be assessed reliably and noninvasively during exercise stress. There is a patient-specific heart rate threshold beyond which TWA continues to increase with increasing heart rates. Heart rate thresholds for the onset of TWA measured during atrial pacing and exercise stress were comparable, indicating that heart rate alone appears to be the main factor of determining the onset of TWA during submaximal exercise stress.

  2. Block of Na(+)/Ca(2+) exchanger by SEA0400 in human right atrial preparations from patients in sinus rhythm and in atrial fibrillation.

    Science.gov (United States)

    Christ, Torsten; Kovács, Peter P; Acsai, Karoly; Knaut, Michael; Eschenhagen, Thomas; Jost, Norbert; Varró, András; Wettwer, Erich; Ravens, Ursula

    2016-10-01

    The Na(+)/Ca(2+) exchanger (NCX) plays a major role in myocardial Ca(2+) homoeostasis, but is also considered to contribute to the electrical instability and contractile dysfunction in chronic atrial fibrillation (AF). Here we have investigated the effects of the selective NCX blocker SEA0400 in human right atrial cardiomyocytes from patients in sinus rhythm (SR) and AF in order to obtain electrophysiological evidence for putative antiarrhythmic activity of this new class of drugs. Action potentials were measured in right atrial trabeculae using conventional microelectrodes. Human myocytes were enzymatically isolated. Rat atrial and ventricular cardiomyocytes were used for comparison. Using perforated-patch, NCX was measured as Ni(2+)-sensitive current during ramp pulses. In ruptured-patch experiments, NCX current was activated by changing the extracellular Ca(2+) concentration from 0 to 1mM in Na(+)-free bath solution (100mM Na(+) intracellular, "Hilgemann protocol"). Although SEA0400 was effective in rat cardiomyocytes, 10µM did not influence action potentials and contractility, neither in SR nor AF. SEA0400 (10μM) also failed to affect human atrial NCX current measured with perforated patch. With the "Hilgemann protocol" SEA0400 concentration-dependently suppressed human atrial NCX current, and its amplitude was larger in AF than in SR cardiomyocytes. Our results confirm higher NCX activity in AF than SR. SEA0400 fails to block Ni(2+)-sensitive current in human atrial cells unless unphysiological conditions are used. We speculate that block of NCX with SEA0400 depends on intracellular Na(+) concentration.

  3. Splanchnic removal of human alpha-atrial natriuretic peptide in humans: enhancement after food intake

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik; Bendtsen, Flemming; Gerbes, A L

    1990-01-01

    In order to assess the effect of food ingestion on splanchnic disposal of human alpha-atrial natriuretic peptide (ANF), hepatic-intestinal removal of ANF was determined before and after a test meal. Hepatic venous and arterial plasma samples were obtained from six subjects, most of whom had only...... disorders of minor degree. Hepatic blood flow (HBF) increased significantly after meal ingestion (1.10 +/- 0.17 [SEM] to 1.51 +/- 0.26 L/min, P less than .01). Baseline arterial ANF (10.9 +/- 3.1 pmol/L) did not change significantly. In contrast, hepatic venous ANF increased after meal intake (5.7 +/- 2...

  4. Splanchnic removal of human alpha-atrial natriuretic peptide in humans: enhancement after food intake

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik Sahl; Bendtsen, F; Gerbes, A L

    1990-01-01

    In order to assess the effect of food ingestion on splanchnic disposal of human alpha-atrial natriuretic peptide (ANF), hepatic-intestinal removal of ANF was determined before and after a test meal. Hepatic venous and arterial plasma samples were obtained from six subjects, most of whom had only...... .05). Splanchnic removal of ANF was 3.0 +/- 0.5 pmol/min before and increased to a maximum value (7.1 +/- 2.2 pmol/min, P less than .05) 35 minutes after ingestion of the meal. Our results showed enhanced splanchnic removal of ANF after food intake. This is due to increased hepatic...

  5. 3D virtual human atria: A computational platform for studying clinical atrial fibrillation.

    Science.gov (United States)

    Aslanidi, Oleg V; Colman, Michael A; Stott, Jonathan; Dobrzynski, Halina; Boyett, Mark R; Holden, Arun V; Zhang, Henggui

    2011-10-01

    Despite a vast amount of experimental and clinical data on the underlying ionic, cellular and tissue substrates, the mechanisms of common atrial arrhythmias (such as atrial fibrillation, AF) arising from the functional interactions at the whole atria level remain unclear. Computational modelling provides a quantitative framework for integrating such multi-scale data and understanding the arrhythmogenic behaviour that emerges from the collective spatio-temporal dynamics in all parts of the heart. In this study, we have developed a multi-scale hierarchy of biophysically detailed computational models for the human atria--the 3D virtual human atria. Primarily, diffusion tensor MRI reconstruction of the tissue geometry and fibre orientation in the human sinoatrial node (SAN) and surrounding atrial muscle was integrated into the 3D model of the whole atria dissected from the Visible Human dataset. The anatomical models were combined with the heterogeneous atrial action potential (AP) models, and used to simulate the AP conduction in the human atria under various conditions: SAN pacemaking and atrial activation in the normal rhythm, break-down of regular AP wave-fronts during rapid atrial pacing, and the genesis of multiple re-entrant wavelets characteristic of AF. Contributions of different properties of the tissue to mechanisms of the normal rhythm and arrhythmogenesis were investigated. Primarily, the simulations showed that tissue heterogeneity caused the break-down of the normal AP wave-fronts at rapid pacing rates, which initiated a pair of re-entrant spiral waves; and tissue anisotropy resulted in a further break-down of the spiral waves into multiple meandering wavelets characteristic of AF. The 3D virtual atria model itself was incorporated into the torso model to simulate the body surface ECG patterns in the normal and arrhythmic conditions. Therefore, a state-of-the-art computational platform has been developed, which can be used for studying multi

  6. Atrial distension, haemodilution, and acute control of renin release during water immersion in humans

    DEFF Research Database (Denmark)

    Gabrielsen, A; Pump, B; Bie, P;

    2002-01-01

    We tested the hypothesis that atrial distension (stimulation of cardiopulmonary baroreceptors) is not the single pivotal stimulus for the acute suppression of renin release during water immersion in humans and that immersion-induced haemodilution constitutes an important additional stimulus...... immersion. During WI, central venous pressure (CVP) and left atrial diameter (LAD) increased (P mL(-1) h......), and markedly inhibited suppression of PRA, which decreased by 0.4 +/- 0.1 ng mL(-1) h(-1) (to 87 +/- 4% of baseline values, P

  7. Slow conduction in the border zones of patchy fibrosis stabilises the drivers for atrial fibrillation: Insights from multi-scale human atrial modelling

    Directory of Open Access Journals (Sweden)

    Ross Morgan

    2016-10-01

    Full Text Available Introduction. The genesis of atrial fibrillation (AF and success of AF ablation therapy have been strongly linked with atrial fibrosis. Increasing evidence suggests that patient-specific distributions of fibrosis may determine the locations of electrical drivers (rotors sustaining AF, but the underlying mechanisms are incompletely understood. This study aims to elucidate a missing mechanistic link between patient-specific fibrosis distributions and AF drivers. Methods. 3D atrial models integrated human atrial geometry, rule-based fibre orientation, region-specific electrophysiology and AF-induced ionic remodelling. A novel detailed model for an atrial fibroblast was developed, and effects of myocyte-fibroblast (M-F coupling were explored at single-cell, 1D tissue and 3D atria levels. Left atrial LGE MRI datasets from 3 chronic AF patients were segmented to provide the patient-specific distributions of fibrosis. The data was non-linearly registered and mapped to the 3D atria model. Six distinctive fibrosis levels (0 – healthy tissue, 5 – dense fibrosis were identified based on LGE MRI intensity and modelled as progressively increasing M-F coupling and decreasing atrial tissue coupling. Uniform 3D atrial model with diffuse (level 2 fibrosis was considered for comparison.Results. In single cells and tissue, the largest effect of atrial M-F coupling was on the myocyte resting membrane potential, leading to partial inactivation of sodium current and reduction of conduction velocity (CV. In the 3D atria, further to the M-F coupling, effects of fibrosis on tissue coupling greatly reduce atrial CV. AF was initiated by fast pacing in each 3D model with either uniform or patient-specific fibrosis. High variation in fibrosis distributions between the models resulted in varying complexity of AF, with several drivers emerging. In the diffuse fibrosis models, waves randomly meandered through the atria, whereas in each the patient-specific models, rotors

  8. Simulation of biatrial conduction via different pathways during sinus rhythm with a detailed human atrial model

    Institute of Scientific and Technical Information of China (English)

    Dong-dong DENG; Ying-lan GONG; Guo-fa SHOU; Pei-feng JIAO; Heng-gui ZHANG; Xue-song YE; Ling XIA

    2012-01-01

    In order to better understand biatrial conduction,investigate various conduction pathways,and compare the differences between isotropic and anisotropic conductions in human atria,we present a simulation study of biatrial conduction with known/assumed conduction pathways using a recently developed human atrial model.In addition to known pathways:(1) Bachmann's bundle (BB),(2) limbus of fossa ovalis (LFO),and (3) coronary sinus (CS),we also hypothesize that there exist two fast conduction bundles that connect the crista terminalis (CT),LFO,and CS.Our simulation demonstrates that use of these fast conduction bundles results in a conduction pattern consistent with experimental data.The comparison of isotropic and anisotropoic conductions in the BB case showed that the atrial working muscles had small effect on conduction time and conduction speed,although the conductivities assigned in anisotropic conduction were two to four times higher than the isotropic conduction.In conclusion,we suggest that the hypothesized intercaval bundles play a significant role in the biatrial conduction and that myofiber orientation has larger effects on the conduction system than the atrial working muscles.This study presents readers with new insights into human atrial conduction.

  9. Pharmacologic Atrial Natriuretic Peptide Reduces Human Leg Capillary Filtration

    Science.gov (United States)

    Watenpaugh, Donald E.; Vissing, Susanne F.; Lane, Lynda D.; Buckey, Jay C.; Firth, Brian G.; Erdman, William; Hargens, Alan R.; Blomqvist, C. Gunnar

    1995-01-01

    Atrial natriuretic peptide (ANP) is produced and secreted by atrial cells. We measured calf capillary filtration rate with prolonged venous-occlusion plethys-mography of supine health male subjects during pharmacologic infusion of ANP (48 pmol/kg/min for 15 min; n equals 6) and during placebo infusion (n equals 7). Results during infusions were compared to prior control measurements. ANP infusion increased plasma (ANP) from 30 plus or minus 4 to 2,568 plus or minus 595 pmol/L. Systemic hemoconcentration occurred during ANP infusion; mean hematocrit and plasma colloid osmotic pressure increased 4.6 and 11.3 percent respectively, relative to pre-infusion baseline values (p is less than 0.05). Mean calf filtration, however was significantly reduced from 0.15 to 0.08 ml/100 ml/min with ANP. Heart rate increased 20 percent with ANP infusion, wheras blood pressure was unchanged. Calf conductance (blood flow/arterial pressure) and venous compliance were unaffected by ANP infusion. Placebo infusion had no effect relative to prior baseline control measurements. Although ANP induced systemic capillary filtration, in the calf, filtration was reduced with ANP. Therefore, phamacologic ANP infusion enhances capillary filtration from the systemic circulation, perhaps at upper body or splanchic sites or both, while having the opposite effect in the leg.

  10. Simulation of biatrial conduction via different pathways during sinus rhythm with a detailed human atrial model*

    OpenAIRE

    Deng, Dong-dong; Gong, Ying-lan; Shou, Guo-fa; Jiao, Pei-feng; Zhang, Heng-gui; Ye, Xue-song; Xia, Ling

    2012-01-01

    In order to better understand biatrial conduction, investigate various conduction pathways, and compare the differences between isotropic and anisotropic conductions in human atria, we present a simulation study of biatrial conduction with known/assumed conduction pathways using a recently developed human atrial model. In addition to known pathways: (1) Bachmann’s bundle (BB), (2) limbus of fossa ovalis (LFO), and (3) coronary sinus (CS), we also hypothesize that there exist two fast conducti...

  11. Atrial Ectopics Precipitating Atrial Fibrillation

    OpenAIRE

    Johnson Francis

    2015-01-01

    Holter monitor tracing showing blocked atrial ectopics and atrial ectopic precipitating atrial fibrillation is being demonstrated. Initially it was coarse atrial fibrillation, which rapidly degenerated into fine atrial fibrillation.

  12. Some aspects of the mitochondrial oxidative metabolism in human atrial tissue during cardiopulmonary by-pass.

    Science.gov (United States)

    Corbucci, G G; Gasparetto, A; Antonelli, M; Bufi, M; De Blasi, R A

    1987-01-01

    Following previous research on the hypoxic cell in human circulatory shock, the present work has investigated some mitochondrial oxidative aspects in atrial biopsies taken during cardiopulmonary by-pass. Cardioplegic solution and hypothermia were administered to 10 patients and the atrial samples were collected before and after aortic clamping. The results show a cellular protective effect of cardioplegia and hypothermia on the electron-transport chain, even if the enzymes with high KmO2 appear to be more sensitive to ischaemia. The results suggest a metabolic injury rather than an oxidative damage due to the induced ischaemia, alterations to fatty-acid beta-oxidation being especially notable. Because of the unchanged oxidative capacities, the oxyradical generation and the peroxidative damage appear to be irrelevant in the ischaemic period and during the course of reperfusion. Further studies are needed to elucidate the metabolic damage and the therapeutic implications due to the induced ischaemia in the myocardial cell during the aortic clamping.

  13. Can contrast-enhanced multi-detector computed tomography replace transesophageal echocardiography for the detection of thrombogenic milieu and thrombi in the left atrial appendage. A prospective study with 124 patients; Kann die kontrastmittelverstaerkte Mehrzeilen-Computertomografie die transoesophageale Echokardiografie bei der Detektion von thrombogenem Milieu und Vorhofohrthromben ersetzen? Eine prospektive Studie mit 124 Patienten

    Energy Technology Data Exchange (ETDEWEB)

    Homsi, R.; Luetkens, J.A.; Schild, H.H.; Naehle, C.P. [Bonn Univ. (Germany). Dept. of Radiology; Nath, B. [SHG-KLliniken Voelklingen (Germany). Dept. of Medicine I - Cardiology; Schwab, J.O. [Bonn Univ. (Germany). Dept. of Medicine I - Cardiology

    2016-01-15

    To assess the diagnostic value of contrast-enhanced multi-detector computed tomography (MD-CT) for identifying patients with left atrial appendage (LAA) thrombus or circulatory stasis. 124 patients with a history of atrial fibrillation and/or cerebral ischemia (83 men, mean age 58.6 ± 12.4 years) and with a clinical indication for MD-CT of the heart and for transesophageal echocardiography (TEE) were included in the study. LAA thrombus or thrombogenic milieu was visually identified in TEE and MD-CT. In addition, MD-CT was analyzed quantitatively measuring the Hounsfield units (HU) of the left atrium (LA), the LAA and the ascending aorta (AA), and calculating the HU ratios LAA/AA (HU [LAA/AA]) und LAA/LA (HU [LAA/LA]). Sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) were calculated. The prevalence of a thrombus or thrombogenic milieu as assessed by TEE was 21.8 %. The HU ratio was lower in patients with thrombus or thrombogenic milieu (HU [LAA/AA]: 0.590 ± 0.248 vs. 0.909 ± 0.141; p < 0.001 und HU [LAA/LA] 0.689 ± 0.366 vs. 1.082 ± 0.228; p < 0.001). For the diagnosis of thrombus or a thrombogenic milieu, visual analysis yielded a sensitivity of 81.5 %, a specificity of 96.9 %, a PPV of 87.5 % and a NPV of 95.2 %. By combining visual and quantitative analysis with one criterion being positive, the specificity decreased to 91.8 %, the sensitivity to 77.8 %, the PPV to 72.4 %, and the NPV to 94.9 %. Visual analysis of the LAA in the evaluation of thrombus or thrombogenic milieu yields a high NPV of 95.1 % and may especially be useful to rule out LAA thrombi in patients with contraindications for TEE. Additional calculation of HU ratios did not improve the diagnostic performance of MD-CT.

  14. Direct differentiation of atrial and ventricular myocytes from human embryonic stem cells by alternating retinoid signals

    Institute of Scientific and Technical Information of China (English)

    Qiangzhe Zhang; Li Chen; Tian Tian; Xin Wang; Pu Li; Jurgen Hescheler; Guangju Ji; Yue Ma; Junjie Jiang; Pengcheng Han; Qi Yuan; Jing Zhang; Xiaoqian Zhang; Yanyan Xu; Henghua Cao; Qingzhang Meng

    2011-01-01

    Although myocyte cell transplantation studies have suggested a promising therapeutic potential for myocardial infarction, a major obstacle to the development of clinical therapies for myocardial repair is the difficulties associated with obtaining relatively homogeneous ventricular myocytes for transplantation. Human embryonic stem cells (hESCs)are a promising source of cardiomyocytes. Here we report that retinoid signaling regulates the fate specification of atrial versus ventricular myocytes during cardiac differentiation of hESCs. We found that both Noggin and the panretinoic acid receptor antagonist BMS-189453 (RAi) significantly increased the cardiac differentiation efficiency of hESCs. To investigate retinoid functions, we compared Noggin+RAi-treated cultures with Noggin+RA-treated cultures. Our results showed that the expression levels of the ventricular-specific gene IRX-4 were radically elevated in Noggin+RAi-treated cultures. MLC-2V, another ventricular-specific marker, was expressed in the majority of the cardiomyocytes in Noggin+RAi-treated cultures, hut not in the cardiomyocytes of Noggin+RA-treated cultures. Flow cytometry analysis and electrophysiologicai studies indicated that with 64.7 ± 0.88% (mean ± s.e.m) cardiac differentiation efficiency, 83% of the cardiomyocytes in Noggin+RAi-treated cultures had embryonic ventricular-like action potentials (APs). With 50.7 ± 1.76% cardiac differentiation efficiency, 94% of the cardiomyocytes in Noggin+RA-treated cultures had embryonic atrial-like APs. These results were further confirmed by imaging studies that assessed the patterns and properties of the Ca2+ sparks of the cardiomyocytes from the two cultures. These findings demonstrate that retinoid signaling specifies the atrial versus ventricular differentiation of hESCs. This study also shows that relatively homogeneous embryonic atrial- and ventricular-like myocyte populations can be efficiently derived from hESCs by specifically regulating Noggin

  15. Cardiac remodeling as a consequence of atrial fibrillation: An anatomical study of perfusion-fixed human heart specimens

    Institute of Scientific and Technical Information of China (English)

    Christopher D Rolfes; Stephen A Howard; Ryan P Goff; Paul A Iaizzo

    2011-01-01

    Background Atrial fibrillation(AF)causes a continuum of atrial anatomical remodeling.Methods Using a library of perfusion-fixed human hearts,specimens with AF were compared to controls.During this preliminary assessment study,direct measurements were taken of atrial volume,pulmonary vein(PV)circumference,and left atrial(LA)wall thicknesses.Results Hearts with AF typically had larger atrial volumes,as well as a much larger variation in volume compared to controls(range of 59.6-227.1 mL in AF hearts compared to 65.1-115.9 mL in controls).For all hearts,right PVs were larger than left PVs(mean: 171.4±84.6 mm' for right and 118.2±50.1 mm2 for left P<0.005).LA wall thicknesses ranged from 0.7 mm to 3.1 min for both AF and control hearts.Conclusions Hearts with AF had a large range of sizes which is consistent with the progression of atrial remodeling during AF.The large range of thicknesses will influence the amount of energy needed to create transmural lesions during ablation procedures.

  16. Left Atrial Ablation for Atrial Fibrillation

    Science.gov (United States)

    Sternik, Leonid; Schaff, Hartzel V.; Luria, David; Glikson, Michael; Kogan, Alexander; Malachy, Ateret; First, Maya; Raanani, Ehud

    2011-01-01

    The maze procedure is the gold standard for the ablation of atrial fibrillation, and the “box lesion” around the pulmonary veins is the most important part of this procedure. We have created this lesion with a bipolar radiofrequency ablator, abandoning the usual use of this device (to achieve bilateral epicardial isolation of the pulmonary veins). From March 2004 through the end of May 2010, we performed surgical ablation of atrial fibrillation in 240 patients. Of this number, 205 underwent operation by a hybrid maze technique and the remaining 35 (our study cohort) underwent the creation of a box lesion around the pulmonary veins by means of a bipolar radiofrequency device. Ablation lines were created by connecting the left atriotomy to the amputated left atrial appendage, with 2 ablation lines made with a bipolar radiofrequency device above and below the pulmonary veins. Lesions were made along the transverse and oblique sinuses by epicardial and endocardial application of a bipolar device. The left atrial isthmus was ablated by bipolar radiofrequency and cryoprobe. No complications were associated with the box lesion: 90% and 89% of patients were in sinus rhythm at 3 and 6 months of follow-up, respectively. By creating a box lesion around the pulmonary veins, we expect to improve transmurality by means of epicardial and endocardial ablation of 1 rather than 2 layers of atrial wall, as in epicardial pulmonary vein isolation. Isolation of the entire posterior wall of the left atrium is better electrophysiologically and renders dissection around the pulmonary veins unnecessary. PMID:21494518

  17. A three-dimensional finite element model of human atrial anatomy: new methods for cubic Hermite meshes with extraordinary vertices.

    Science.gov (United States)

    Gonzales, Matthew J; Sturgeon, Gregory; Krishnamurthy, Adarsh; Hake, Johan; Jonas, René; Stark, Paul; Rappel, Wouter-Jan; Narayan, Sanjiv M; Zhang, Yongjie; Segars, W Paul; McCulloch, Andrew D

    2013-07-01

    High-order cubic Hermite finite elements have been valuable in modeling cardiac geometry, fiber orientations, biomechanics, and electrophysiology, but their use in solving three-dimensional problems has been limited to ventricular models with simple topologies. Here, we utilized a subdivision surface scheme and derived a generalization of the "local-to-global" derivative mapping scheme of cubic Hermite finite elements to construct bicubic and tricubic Hermite models of the human atria with extraordinary vertices from computed tomography images of a patient with atrial fibrillation. To an accuracy of 0.6 mm, we were able to capture the left atrial geometry with only 142 bicubic Hermite finite elements, and the right atrial geometry with only 90. The left and right atrial bicubic Hermite meshes were G1 continuous everywhere except in the one-neighborhood of extraordinary vertices, where the mean dot products of normals at adjacent elements were 0.928 and 0.925. We also constructed two biatrial tricubic Hermite models and defined fiber orientation fields in agreement with diagrammatic data from the literature using only 42 angle parameters. The meshes all have good quality metrics, uniform element sizes, and elements with aspect ratios near unity, and are shared with the public. These new methods will allow for more compact and efficient patient-specific models of human atrial and whole heart physiology. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. 经胸超声心动图评价右心耳形态的可行性及方法学研究%Feasibility and methodology study of tran-sthoracic echocardiography for assessment of the morphology of right atrial appendage

    Institute of Scientific and Technical Information of China (English)

    陈欧迪; 林琼雯; 费洪文; 郑智超; 陈烁

    2015-01-01

    目的:探讨经胸超声心动图评价右心耳的可行性及方法.方法:分别于胸骨左缘旁、心尖部、剑突下、平卧位胸骨右缘及右侧卧位胸骨右缘显示右心耳结构,比较不同透声部位及切面显示右心耳的成功率及图像质量.结果:不同透声部位的相应切面显示右心耳的成功率明显不同.胸骨左缘旁及心尖部、剑突下、平卧位胸骨右缘、右侧卧位胸骨右缘显示右心耳的成功率分别为10.85%、28.83%、50.46%、84.97%.右侧卧位胸骨右缘切面显示右心耳的成功率最高,图像也最为清晰.结论:经胸超声心动图显示右心耳具有一定的可行性且右侧卧位胸骨右缘切面是显示右心耳的最佳切面.%AIM: To explore the feasibility and methodology of transthoracic echocardiography ( TTE ) in the evaluation of right atrial appendage ( RAA ) . METHODS: Left parasternal view, apical view, subcostal view, right parasternal view with a supine position and right parasternal view with a right lateral decubitus were chosen as the reference views in displaying RAA. The success rate and image quality of viewing RAA through these acoustic windows were compared. RESULTS: There was a significant difference in the success rate and image quality among various acoustic windows in displaying RAA. The success rate were 10.85%, 28.83%, 50. 46%, 84. 97% in left parasternal view and apical view, subcostal view, right parasternal view with a supine position and right parasternal view with a right lateral decubitus, respec⁃tively. The success rate was highest and the image quality was optimal in the right parasternal view with a right lateral decubitus. CONCLUSION:It is feasible for TTE to display RAA, and right parasternal view with a right lateral decubitus could be regarded as the optimum orientation for displaying RAA.

  19. Doppler echo evaluation of pulmonary venous-left atrial pressure gradients: human and numerical model studies

    Science.gov (United States)

    Firstenberg, M. S.; Greenberg, N. L.; Smedira, N. G.; Prior, D. L.; Scalia, G. M.; Thomas, J. D.; Garcia, M. J.

    2000-01-01

    The simplified Bernoulli equation relates fluid convective energy derived from flow velocities to a pressure gradient and is commonly used in clinical echocardiography to determine pressure differences across stenotic orifices. Its application to pulmonary venous flow has not been described in humans. Twelve patients undergoing cardiac surgery had simultaneous high-fidelity pulmonary venous and left atrial pressure measurements and pulmonary venous pulsed Doppler echocardiography performed. Convective gradients for the systolic (S), diastolic (D), and atrial reversal (AR) phases of pulmonary venous flow were determined using the simplified Bernoulli equation and correlated with measured actual pressure differences. A linear relationship was observed between the convective (y) and actual (x) pressure differences for the S (y = 0.23x + 0.0074, r = 0.82) and D (y = 0.22x + 0.092, r = 0.81) waves, but not for the AR wave (y = 0. 030x + 0.13, r = 0.10). Numerical modeling resulted in similar slopes for the S (y = 0.200x - 0.127, r = 0.97), D (y = 0.247x - 0. 354, r = 0.99), and AR (y = 0.087x - 0.083, r = 0.96) waves. Consistent with numerical modeling, the convective term strongly correlates with but significantly underestimates actual gradient because of large inertial forces.

  20. Mechanisms of arrhythmogenesis related to calcium-driven alternans in a model of human atrial fibrillation

    Science.gov (United States)

    Chang, Kelly C.; Trayanova, Natalia A.

    2016-11-01

    The occurrence of atrial fibrillation (AF) is associated with progressive changes in the calcium handling system of atrial myocytes. Calcium cycling instability has been implicated as an underlying mechanism of electrical alternans observed in patients who experience AF. However, the extent to which calcium-induced alternation of electrical activity in the atria contributes to arrhythmogenesis is unknown. In this study, we investigated the effects of calcium-driven alternans (CDA) on arrhythmia susceptibility in a biophysically detailed, 3D computer model of the human atria representing electrical and structural remodeling secondary to chronic AF. We found that elevated propensity to CDA rendered the atria vulnerable to ectopy-induced arrhythmia. It also increased the complexity and persistence of arrhythmias induced by fast pacing, with unstable scroll waves meandering and frequently breaking up to produce multiple wavelets. Our results suggest that calcium-induced electrical instability may increase arrhythmia vulnerability and promote increasing disorganization of arrhythmias in the chronic AF-remodeled atria, thus playing an important role in the progression of the disease.

  1. Study of atrial arrhythmias in a computer model based on magnetic resonance images of human atria

    Science.gov (United States)

    Virag, N.; Jacquemet, V.; Henriquez, C. S.; Zozor, S.; Blanc, O.; Vesin, J.-M.; Pruvot, E.; Kappenberger, L.

    2002-09-01

    The maintenance of multiple wavelets appears to be a consistent feature of atrial fibrillation (AF). In this paper, we investigate possible mechanisms of initiation and perpetuation of multiple wavelets in a computer model of AF. We developed a simplified model of human atria that uses an ionic-based membrane model and whose geometry is derived from a segmented magnetic resonance imaging data set. The three-dimensional surface has a realistic size and includes obstacles corresponding to the location of major vessels and valves, but it does not take into account anisotropy. The main advantage of this approach is its ability to simulate long duration arrhythmias (up to 40 s). Clinically relevant initiation protocols, such as single-site burst pacing, were used. The dynamics of simulated AF were investigated in models with different action potential durations and restitution properties, controlled by the conductance of the slow inward current in a modified Luo-Rudy model. The simulation studies show that (1) single-site burst pacing protocol can be used to induce wave breaks even in tissue with uniform membrane properties, (2) the restitution-based wave breaks in an atrial model with realistic size and conduction velocities are transient, and (3) a significant reduction in action potential duration (even with apparently flat restitution) increases the duration of AF.

  2. Right versus left atrial pacing in patients with sick sinus syndrome and paroxysmal atrial fibrillation (Riverleft study): Study protocol for randomized controlled trial

    NARCIS (Netherlands)

    T. Ramdjan (T.); L. Van Der Does (Lisette); S.P. Knops (Simon); J. Res (Jan); N. de Groot (Natasja)

    2014-01-01

    textabstractBackground: The incidence of sick sinus syndrome will increase due to population ageing. Consequently, this will result in an increase in the number of pacemaker implantations. The atrial lead is usually implanted in the right atrial appendage, but this position may be ineffective for pr

  3. Hepatic-intestinal disposal of endogenous human alpha atrial natriuretic factor99-126 in patients with cirrhosis

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik; Bendtsen, Flemming; Schütten, H J

    1990-01-01

    Hepatic-intestinal disposal of endogenous human alpha atrial natriuretic factor99-126 (ANF) was assessed in 13 patients with cirrhosis (six Child-Turcotte class A, five class B, and two class C) and eight control subjects. The Fick principle was applied during hepatic vein catheterization. Arterial...

  4. Hepatic-intestinal disposal of endogenous human alpha atrial natriuretic factor99-126 in patients with cirrhosis

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik Sahl; Bendtsen, F; Schütten, H J

    1990-01-01

    Hepatic-intestinal disposal of endogenous human alpha atrial natriuretic factor99-126 (ANF) was assessed in 13 patients with cirrhosis (six Child-Turcotte class A, five class B, and two class C) and eight control subjects. The Fick principle was applied during hepatic vein catheterization. Arterial...

  5. Impact of pulmonary vein isolation on atrial vagal activity and atrial electrical remodeling

    Institute of Scientific and Technical Information of China (English)

    Yingxue Dong; Shulong Zhang; Lianjun Gao; Hongwei Zhao; Donghui Yang; Yunlong Xia; Yanzong Yang

    2008-01-01

    Objective Mechanisms of pulmonary vein isolation (PVI) for atrial fibrillation remain controversy.This study aimed to investigate the impact of PVI on vagal modulation to atria.Methods Eighteen adult mongrel dogs under general anesthesia were randomly divided into two groups.Bilateral cervical sympathovagal trunks were decentralized and sympathetic effects was blocked by metoprolol administration.Atrial electrical remodeling (AER) was established by rapid right atrial pacing at the rate of 600 bpm for 30 minutes.PVI was performed in group A.Atrial effective refractory period (ERP),vulnerability window (VW) of atrial fibrillation,and sinus rhythm cycle length (SCL) were measured at baseline and during vagal stimulation before and after atrial rapid pacing with and without PVI at fight atrial appendage (RAA),left atrial appendage (LAA),distal coronary sinus (CSd) and proximal coronary sinus (CSp).Results (1) Effects of PVI on vagal modulation:Shortening of SCL during vagal stimulation decreased significantly after PVI compared with that before PVI in group A (P<0.001).Shortening of ERP during vagal stimulation decreaseed significantly after PVI compared with that before PVI (P<0.05).VW of atrial fibrillation during vagal stimulation decreased significantly after PVI compared with that before PVI (P<0.05).(2) Effects of PVI on AER:shortening of ERP before and after atrial rapid pacing increased significantly at baseline and vagal stimulation in group B compared with that in group A (P<0.05).VW during vagal stimulation increased significantly after atrial rapid pacing in group B (P<0.05).Conclusion PVI attenuates the vagal modulation to the atria,thereby decreases the susceptibility to atrial fibrillation mediated by vagal activity.PVI releases AER,which maybe contributes to the vagal denervation.Our study indicates that PVI not only can eradicate triggered foci but also modify substrates for AF.(J Geriatr Cardiol 2008;5:28-32)

  6. TASK-1 and TASK-3 may form heterodimers in human atrial cardiomyocytes.

    Science.gov (United States)

    Rinné, Susanne; Kiper, Aytug K; Schlichthörl, Günter; Dittmann, Sven; Netter, Michael F; Limberg, Sven H; Silbernagel, Nicole; Zuzarte, Marylou; Moosdorf, Rainer; Wulf, Hinnerk; Schulze-Bahr, Eric; Rolfes, Caroline; Decher, Niels

    2015-04-01

    TASK-1 channels have emerged as promising drug targets against atrial fibrillation, the most common arrhythmia in the elderly. While TASK-3, the closest relative of TASK-1, was previously not described in cardiac tissue, we found a very prominent expression of TASK-3 in right human auricles. Immunocytochemistry experiments of human right auricular cardiomyocytes showed that TASK-3 is primarily localized at the plasma membrane. Single-channel recordings of right human auricles in the cell-attached mode, using divalent-cation-free solutions, revealed a TASK-1-like channel with a single-channel conductance of about 30pS. While homomeric TASK-3 channels were not found, we observed an intermediate single-channel conductance of about 55pS, possibly reflecting the heteromeric channel formed by TASK-1 and TASK-3. Subsequent experiments with TASK-1/TASK-3 tandem channels or with co-expressed TASK-1 and TASK-3 channels in HEK293 cells or Xenopus oocytes, supported that the 55pS channels observed in right auricles have electrophysiological characteristics of TASK-1/TASK-3 heteromers. In addition, co-expression experiments and single-channel recordings suggest that heteromeric TASK-1/TASK-3 channels have a predominant surface expression and a reduced affinity for TASK-1 blockers. In summary, the evidence for heteromeric TASK-1/TASK-3 channel complexes together with an altered pharmacologic response to TASK-1 blockers in vitro is likely to have further impact for studies isolating ITASK-1 from cardiomyocytes and for the development of drugs specifically targeting TASK-1 in atrial fibrillation treatment.

  7. A novel approach to quickly differential diagnose the macro-reentrant mitral annular atrial tachycardia with left appendage potentials%结合左心耳电位快速鉴别二尖瓣环折返性房性心动过速

    Institute of Scientific and Technical Information of China (English)

    施海峰; 刘旭; 王新华; 谭红伟; 姜伟峰; 周立; 顾佳宁; 王远龙; 杨国澍; 刘玉岗

    2011-01-01

    目的 探讨结合左心耳电位快速鉴别二尖瓣环折返性房性心动过速(房速)的临床应用价值.方法 连续348例心房颤动(房颤)导管消融患者中发生大折返房速时,将环状标测电极置于左心耳内,消融导管置于左心房前壁,根据冠状静脉窦、左心耳和左心房前壁电位的激动模式初步判断大折返房速的机制,然后在Carto系统指导下进行激动标测和拖带标测明确折返机制,评价结合左心耳和冠状静脉窦电位快速鉴别诊断二尖瓣环折返的准确性和特异性.结果 40例房颤患者消融过程中共发生经Carto系统激动标测及拖带验证明确诊断的53种大折返房速,其中24种二尖瓣折返、19种三尖瓣折返和10种房顶依赖的折返.24种二尖瓣折返中,8种为冠状静脉窦近端领先的逆钟向折返,均表现为冠状静脉窦近端-中间-远端-左心耳(CSP-CSM-CSD-LAA)的激动模式,16种是冠状静脉窦远端领先的顺钟向折返,均表现为左心耳-冠状静脉窦远端-中间-近端(LAA-CSD-CSM-CSP)的激动模式.与Carto指导的激动标测和拖带标测出的折返环相比,用CSP-CSM-CSD-LAA或LAA-CSD-CSM-CSP的激动模式判断二尖瓣折返性房速总体敏感性100%,特异性75%,结合左心房前壁电位可进一步提高诊断特异性.结论 结合左心耳电位的快速标测是鉴别二尖瓣环折返性房速的有效方法.%Objective To investigate the feasibility and efficacy of quick mapping by analyzing the left atrial appendage (LAA)potentials to categorize two types of macro-reentrant mitral annular atrial tachycardia (MAAT).Methods Three hundred forty-eight consecutive patients with atrial fibrillation (AF)underwent catheter ablation were enrolled.When macro-reentrant AT occurred,the circular electrodes were placed into LAA to record the changing of activation sequence during mapping and ablating.Simultaneously,the activation sequence mapping guided by Carto system and entrainment

  8. Characterization of Mg2+-regulated TRPM7-like current in human atrial myocytes

    Directory of Open Access Journals (Sweden)

    Macianskiene Regina

    2012-08-01

    Full Text Available Abstract Background TRPM7 (Transient Receptor Potential of the Melastatin subfamily proteins are highly expressed in the heart, however, electrophysiological studies, demonstrating and characterizing these channels in human cardiomyocytes, are missing. Methods We have used the patch clamp technique to characterize the biophysical properties of TRPM7 channel in human myocytes isolated from right atria small chunks obtained from 116 patients in sinus rhythm during coronary artery and valvular surgery. Under whole-cell voltage-clamp, with Ca2+ and K+ channels blocked, currents were generated by symmetrical voltage ramp commands to potentials between -120 and +80 mV, from a holding potential of -80 mV. Results We demonstrate that activated native current has dual control by intracellular Mg2+ (free-Mg2+ or ATP-bound form, and shows up- or down-regulation by its low or high levels, respectively, displaying outward rectification in physiological extracellular medium. High extracellular Mg2+ and Ca2+ block the outward current, while Gd3+, SpM4+, 2-APB, and carvacrol inhibit both (inward and outward currents. Besides, divalents also permeate the channel, and the efficacy sequence, at 20 mM, was Mg2+>Ni2+>Ca2+>Ba2+>Cd2+ for decreasing outward and Ni2+>Mg2+>Ba2+≥Ca2+>Cd2+ for increasing inward currents. The defined current bears many characteristics of heterologously expressed or native TRPM7 current, and allowed us to propose that current under study is TRPM7-like. However, the time of beginning and time to peak as well steady state magnitude (range from 1.21 to 11.63 pA/pF, ncells/patients = 136/77 of induced TRPM7-like current in atrial myocytes from different patients showed a large variability, while from the same sample of human atria all these parameters were very homogenous. We present new information that TRPM7-like current in human myocytes is less sensitive to Mg2+. In addition, in some myocytes (from 24 out of 77 patients that current

  9. A new algorithm to diagnose atrial ectopic origin from multi lead ECG systems--insights from 3D virtual human atria and torso.

    Science.gov (United States)

    Alday, Erick A Perez; Colman, Michael A; Langley, Philip; Butters, Timothy D; Higham, Jonathan; Workman, Antony J; Hancox, Jules C; Zhang, Henggui

    2015-01-01

    Rapid atrial arrhythmias such as atrial fibrillation (AF) predispose to ventricular arrhythmias, sudden cardiac death and stroke. Identifying the origin of atrial ectopic activity from the electrocardiogram (ECG) can help to diagnose the early onset of AF in a cost-effective manner. The complex and rapid atrial electrical activity during AF makes it difficult to obtain detailed information on atrial activation using the standard 12-lead ECG alone. Compared to conventional 12-lead ECG, more detailed ECG lead configurations may provide further information about spatio-temporal dynamics of the body surface potential (BSP) during atrial excitation. We apply a recently developed 3D human atrial model to simulate electrical activity during normal sinus rhythm and ectopic pacing. The atrial model is placed into a newly developed torso model which considers the presence of the lungs, liver and spinal cord. A boundary element method is used to compute the BSP resulting from atrial excitation. Elements of the torso mesh corresponding to the locations of the placement of the electrodes in the standard 12-lead and a more detailed 64-lead ECG configuration were selected. The ectopic focal activity was simulated at various origins across all the different regions of the atria. Simulated BSP maps during normal atrial excitation (i.e. sinoatrial node excitation) were compared to those observed experimentally (obtained from the 64-lead ECG system), showing a strong agreement between the evolution in time of the simulated and experimental data in the P-wave morphology of the ECG and dipole evolution. An algorithm to obtain the location of the stimulus from a 64-lead ECG system was developed. The algorithm presented had a success rate of 93%, meaning that it correctly identified the origin of atrial focus in 75/80 simulations, and involved a general approach relevant to any multi-lead ECG system. This represents a significant improvement over previously developed algorithms.

  10. Atrial natriuretic peptide regulates lipid mobilization and oxygen consumption in human adipocytes by activating AMPK

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Sandra C. [Translational Sciences - Translational Medicine, Novartis Institutes for Biomedical Research, Inc., 220 Massachusetts Avenue, Cambridge, MA 02139 (United States); Chau, Mary D.L.; Yang, Qing [Cardiovascular and Metabolism Disease Area, Novartis Institutes for Biomedical Research, Inc., 100 Technology Square, Cambridge, MA 02139 (United States); Gauthier, Marie-Soleil [Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA 02140 (United States); Clairmont, Kevin B.; Wu, Zhidan; Gromada, Jesper [Cardiovascular and Metabolism Disease Area, Novartis Institutes for Biomedical Research, Inc., 100 Technology Square, Cambridge, MA 02139 (United States); Dole, William P., E-mail: bill.dole@novartis.com [Translational Sciences - Translational Medicine, Novartis Institutes for Biomedical Research, Inc., 220 Massachusetts Avenue, Cambridge, MA 02139 (United States)

    2011-07-08

    Highlights: {yields} Treatment of differentiated human adipocytes with atrial natriuretic peptide (ANP) increased lipolysis and oxygen consumption by activating AMP-activated protein kinase (AMPK). {yields} ANP stimulated lipid mobilization by selective activation of the alpha2 subunit of AMPK and increased energy utilization through activation of both the alpha1 and alpha2 subunits of AMPK. {yields} ANP enhanced adipocyte mitochondrial oxidative capacity as evidenced by induction of oxidative mitochondrial genes and increase in oxygen consumption. {yields} Exposure of human adipocytes to fatty acids and (TNF{alpha}) induced insulin resistance and decreased expression of mitochondrial genes which was restored to normal by ANP. -- Abstract: Atrial natriuretic peptide (ANP) has been shown to regulate lipid and carbohydrate metabolism providing a possible link between cardiovascular function and metabolism by mediating the switch from carbohydrate to lipid mobilization and oxidation. ANP exerts a potent lipolytic effect via cGMP-dependent protein kinase (cGK)-I mediated-stimulation of AMP-activated protein kinase (AMPK). Activation of the ANP/cGK signaling cascade also promotes muscle mitochondrial biogenesis and fat oxidation. Here we demonstrate that ANP regulates lipid metabolism and oxygen utilization in differentiated human adipocytes by activating the alpha2 subunit of AMPK. ANP treatment increased lipolysis by seven fold and oxygen consumption by two fold, both of which were attenuated by inhibition of AMPK activity. ANP-induced lipolysis was shown to be mediated by the alpha2 subunit of AMPK as introduction of dominant-negative alpha2 subunit of AMPK attenuated ANP effects on lipolysis. ANP-induced activation of AMPK enhanced mitochondrial oxidative capacity as evidenced by a two fold increase in oxygen consumption and induction of mitochondrial genes, including carnitine palmitoyltransferase 1A (CPT1a) by 1.4-fold, cytochrome C (CytC) by 1.3-fold, and

  11. Appendage mountable electronic devices conformable to surfaces

    Science.gov (United States)

    Rogers, John; Ying, Ming; Bonifas, Andrew; Lu, Nanshu

    2017-01-24

    Disclosed are appendage mountable electronic systems and related methods for covering and conforming to an appendage surface. A flexible or stretchable substrate has an inner surface for receiving an appendage, including an appendage having a curved surface, and an opposed outer surface that is accessible to external surfaces. A stretchable or flexible electronic device is supported by the substrate inner and/or outer surface, depending on the application of interest. The electronic device in combination with the substrate provides a net bending stiffness to facilitate conformal contact between the inner surface and a surface of the appendage provided within the enclosure. In an aspect, the system is capable of surface flipping without adversely impacting electronic device functionality, such as electronic devices comprising arrays of sensors, actuators, or both sensors and actuators.

  12. Appendage mountable electronic devices conformable to surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, John; Ying, Ming; Bonifas, Andrew; Lu, Nanshu

    2017-01-24

    Disclosed are appendage mountable electronic systems and related methods for covering and conforming to an appendage surface. A flexible or stretchable substrate has an inner surface for receiving an appendage, including an appendage having a curved surface, and an opposed outer surface that is accessible to external surfaces. A stretchable or flexible electronic device is supported by the substrate inner and/or outer surface, depending on the application of interest. The electronic device in combination with the substrate provides a net bending stiffness to facilitate conformal contact between the inner surface and a surface of the appendage provided within the enclosure. In an aspect, the system is capable of surface flipping without adversely impacting electronic device functionality, such as electronic devices comprising arrays of sensors, actuators, or both sensors and actuators.

  13. Atrial natriuretic peptide contributes to physiological control of lipid mobilization in humans.

    Science.gov (United States)

    Moro, Cedric; Crampes, Francois; Sengenes, Coralie; De Glisezinski, Isabelle; Galitzky, Jean; Thalamas, Claire; Lafontan, Max; Berlan, Michel

    2004-05-01

    In humans, lipid mobilization is considered to depend mainly on sympathetic nervous system activation and catecholamine action. A contribution of ANP was hypothesized because we have previously shown that atrial natriuretic peptide (ANP) is a lipolytic agent on isolated human fat cells. Control of lipid-mobilizing mechanisms was investigated using in situ microdialysis in subcutaneous adipose tissue (SCAT) in healthy young men during two successive exercise bouts performed at 35% and 60% peak oxygen consumption (VO2max) after placebo or acute oral tertatolol (nonselective beta-antagonist) treatment. In placebo-treated subjects, infusion of propranolol in the probe (100 micromol/l) only partially reduced (40%) the increment in extracellular glycerol concentration (EGC) promoted by exercise. Moreover, oral beta-adrenergic receptor blockade did not prevent exercise-induced lipid mobilization in SCAT while exerting fat cell beta-adrenergic receptor blockade. Exercise-induced increase in plasma ANP was potently amplified by oral tertatolol. A positive correlation was found between EGC and plasma ANP levels but also between extracellular cGMP (i.e., index of ANP-mediated lipolysis) and EGC. Thus, we demonstrate that exercise-induced lipid mobilization resistant to local propranolol and lipid-mobilizing action observed under oral beta-blockade is related to the action of ANP. Oral beta-adrenergic receptor blockade, which potentiates exercise-induced ANP release by the heart, may contribute to lipid mobilization in SCAT. The potential relevance of an ANP-related lipid-mobilizing pathway is discussed.

  14. Atrial fibrillation

    African Journals Online (AJOL)

    ABEOLUGBENGAS

    patients with atrial fibrillation managed in a referral hospital in Port Harcourt, southern Nigeria. ... treatment despite all the patients having moderate to high risk of stroke ... Keywords: Atrial fibrillation, thrombosis, CHADS2 Score, stroke risk, ...

  15. Caecal epiploic appendagitis: an unlikely occurrence

    Energy Technology Data Exchange (ETDEWEB)

    Macari, M. [Department of Radiology, Abdominal Imaging, NYU School of Medicine, NY (United States)], E-mail: michael.macari@nyumc.org; Laks, S.; Hajdu, C.; Babb, J. [Department of Radiology, Abdominal Imaging, NYU School of Medicine, NY (United States)

    2008-08-15

    Aim: To determine whether epiploic appendagitis occurs in the caecum. Methods: From 2000-2006, 58 cases with classic computed tomography (CT) features of acute epiploic appendagitis (focal round or oval fat density immediately adjacent to the colon with surrounding oedema and stranding, with or without a central area of high attenuation) were identified from a radiology information system and available for review on the picture archiving and communication system (PACS). Cases were assigned to one of six colonic segments: rectum, sigmoid, descending colon, transverse colon, ascending colon, and caecum. The Blyth-Still-Casella procedure was used to derive an exact upper bound on the likelihood of epiploic appendagitis occurring within the caecum. Results: Twenty-eight cases occurred in the sigmoid colon, 16 in the descending colon, four in the transverse colon, and 10 in the ascending colon. No cases of acute epiploic appendagitis were identified in the caecum. Four cases of prospectively dictated caecal epiploic appendagitis were identified from the database. Retrospective review of these cases showed two cases to be epiploic appendagitis of the ascending colon. The third case demonstrated peritoneal thickening without evidence of an inflamed epiploic appendage. The fourth case was caecal diverticulitis. Based on these findings there is 95% confidence that no more than 4.6% of patients with epiploic appendagitis will show this condition within the caecum. Conclusion: In the authors' experience, epiploic appendagitis does not occur in the caecum. Therefore, it is an unlikely cause for an inflammatory process in this region and other conditions should be considered.

  16. Appendagitis following Diagnostic Laparoscopy and Laparoscopic Appendicectomy

    Directory of Open Access Journals (Sweden)

    R. Kumar

    2016-01-01

    Full Text Available Appendagitis is an uncommon clinical entity, often not recognised, and mistaken for more serious infective conditions. We describe a proven case of appendagitis which occurred after confirmed appendicitis. We postulate that this condition can coexist with appendicitis and indeed may be the result of coinflammation. This has several implications. Firstly, clinicians must retain an index of suspicion for this condition in a patient with localised abdominal pain which occurs after appendicitis. Secondly, it would be reasonable to suggest careful examination of colocated appendages in a patient with an otherwise normal-appearing appendix. Treatment might require laparoscopic resection, as performed in this case.

  17. A 2D Electromechanical Model of Human Atrial Tissue Using the Discrete Element Method.

    Science.gov (United States)

    Brocklehurst, Paul; Adeniran, Ismail; Yang, Dongmin; Sheng, Yong; Zhang, Henggui; Ye, Jianqiao

    2015-01-01

    Cardiac tissue is a syncytium of coupled cells with pronounced intrinsic discrete nature. Previous models of cardiac electromechanics often ignore such discrete properties and treat cardiac tissue as a continuous medium, which has fundamental limitations. In the present study, we introduce a 2D electromechanical model for human atrial tissue based on the discrete element method (DEM). In the model, single-cell dynamics are governed by strongly coupling the electrophysiological model of Courtemanche et al. to the myofilament model of Rice et al. with two-way feedbacks. Each cell is treated as a viscoelastic body, which is physically represented by a clump of nine particles. Cell aggregations are arranged so that the anisotropic nature of cardiac tissue due to fibre orientations can be modelled. Each cell is electrically coupled to neighbouring cells, allowing excitation waves to propagate through the tissue. Cell-to-cell mechanical interactions are modelled using a linear contact bond model in DEM. By coupling cardiac electrophysiology with mechanics via the intracellular Ca(2+) concentration, the DEM model successfully simulates the conduction of cardiac electrical waves and the tissue's corresponding mechanical contractions. The developed DEM model is numerically stable and provides a powerful method for studying the electromechanical coupling problem in the heart.

  18. Feasibility of In-Vivo Simulation of Acute Hemodynamics in Human Atrial Fibrillation

    Science.gov (United States)

    Sramko, Marek; Wichterle, Dan; Kautzner, Josef

    2016-01-01

    This study evaluated hemodynamic feasibility and reproducibility of a new method for in vivo simulation of human atrial fibrillation (AF). The method was tested during sinus rhythm in 10 patients undergoing catheter ablation for AF. A simple electronic device was assembled that allowed triggering a cardiac stimulator by predefined series of RR intervals. Irregular RR interval sequences with a mean heart rate of 90/min and 130/min were obtained from ECG recordings of another patients with AF. Simultaneous atrioventricular pacing was delivered by catheters placed inside the coronary sinus and at the His bundle region. Hemodynamic effect of the simulated AF was assessed by invasive measurement of the left ventricular (LV) pressure, dP/dt, and Tau. Compared to regular pacing at the same mean heart rate, the simulated AF significantly impaired the LV both systolic and diastolic function. Repeated AF pacing in the same patients generated similar LV hemodynamics. The proposed method provides a realistic and reproducible in-vivo model of AF. It can be exploited for investigation of the hemodynamic consequences of AF in various patient populations. PMID:27764240

  19. Innervation of the sinu-atrial node and neighbouring regions in two human embryos.

    Science.gov (United States)

    Orts Llorca, F; Domenech Mateu, J M; Puerta Fonolla, J

    1979-03-01

    In human embryos of 20 to 23 mm (36 to 40 days) it is possible to identify on the right side a nerve that we may call the sinusal, which originates by several roots from the nervus vagus dexter (Figs. 1A, B, D), descending through the right ventrolateral face of the primary trachea and right bronchus (Fig. 2, arrows). Beaded in appearance, it gives a fine anastomotic branch which, passing in front of the arteria pulmonalis dextra, passes to the left side (Figs. 2B, C, D; AN). At this level it gives the large branch for the nodus sinoatrialis which, penetrating through the wall of the superior vena cava, provides a rich innervation for the nodus sinoatrialis which is already in an advanced stage of differentiation (Fig. 3, 2; Cy, D, AN). Afterwards it gives fine branches which, following the atrial fold, are distributed throughout the posterior face of the atrium dextrum (Fig. 3). It increases in diameter and, passing through the angle formed by the right pulmonary veins with the atrium dextrum, reaches the intrapericardial portion of the inferior vena cava in the vicinity of its outlet from the atrium (Fig. 3, arrows). The whole innervation is parasympathetic at the stages studied.

  20. Up-regulation of miR-31 in human atrial fibrillation begets the arrhythmia by depleting dystrophin and neuronal nitric oxide synthase

    Science.gov (United States)

    Carnicer, Ricardo; Recalde, Alice; Muszkiewicz, Anna; Jayaram, Raja; Carena, Maria Cristina; Wijesurendra, Rohan; Stefanini, Matilde; Surdo, Nicoletta C.; Lomas, Oliver; Ratnatunga, Chandana; Sayeed, Rana; Krasopoulos, George; Rajakumar, Timothy; Bueno-Orovio, Alfonso; Verheule, Sander; Fulga, Tudor A.; Rodriguez, Blanca; Schotten, Ulrich

    2016-01-01

    Atrial fibrillation (AF) is a growing public health burden, and its treatment remains a challenge. AF leads to electrical remodeling of the atria, which in turn promotes AF maintenance and resistance to treatment. Although remodeling has long been a therapeutic target in AF, its causes remain poorly understood. We show that atrial-specific up-regulation of microRNA-31 (miR-31) in goat and human AF depletes neuronal nitric oxide synthase (nNOS) by accelerating mRNA decay and alters nNOS subcellular localization by repressing dystrophin translation. By shortening action potential duration and abolishing rate-dependent adaptation of the action potential duration, miR-31 overexpression and/or disruption of nNOS signaling recapitulates features of AF-induced remodeling and significantly increases AF inducibility in mice in vivo. By contrast, silencing miR-31 in atrial myocytes from patients with AF restores dystrophin and nNOS and normalizes action potential duration and its rate dependency. These findings identify atrial-specific up-regulation of miR-31 in human AF as a key mechanism causing atrial dystrophin and nNOS depletion, which in turn contributes to the atrial phenotype begetting this arrhythmia. miR-31 may therefore represent a potential therapeutic target in AF. PMID:27225184

  1. Arrhythmias, elicited by catecholamines and serotonin, vanish in human chronic atrial fibrillation.

    Science.gov (United States)

    Christ, Torsten; Rozmaritsa, Nadiia; Engel, Andreas; Berk, Emanuel; Knaut, Michael; Metzner, Katharina; Canteras, Manuel; Ravens, Ursula; Kaumann, Alberto

    2014-07-29

    Atrial fibrillation (AF) is the most common heart rhythm disorder. Transient postoperative AF can be elicited by high sympathetic nervous system activity. Catecholamines and serotonin cause arrhythmias in atrial trabeculae from patients with sinus rhythm (SR), but whether these arrhythmias occur in patients with chronic AF is unknown. We compared the incidence of arrhythmic contractions caused by norepinephrine, epinephrine, serotonin, and forskolin in atrial trabeculae from patients with SR and patients with AF. In the patients with AF, arrhythmias were markedly reduced for the agonists and abolished for forskolin, whereas maximum inotropic responses were markedly blunted only for serotonin. Serotonin and forskolin produced spontaneous diastolic Ca(2+) releases in atrial myocytes from the patients with SR that were abolished or reduced in myocytes from the patients with AF. For matching L-type Ca(2+)-current (ICa,L) responses, serotonin required and produced ∼ 100-fold less cAMP/PKA at the Ca(2+) channel domain compared with the catecholamines and forskolin. Norepinephrine-evoked ICa,L responses were decreased by inhibition of Ca(2+)/calmodulin-dependent kinase II (CaMKII) in myocytes from patients with SR, but not in those from patients with AF. Agonist-evoked phosphorylation by CaMKII at phospholamban (Thr-17), but not of ryanodine2 (Ser-2814), was reduced in trabeculae from patients with AF. The decreased CaMKII activity may contribute to the blunting of agonist-evoked arrhythmias in the atrial myocardium of patients with AF.

  2. Chemical-defined and albumin-free generation of human atrial and ventricular myocytes from human pluripotent stem cells

    Directory of Open Access Journals (Sweden)

    Fei Pei

    2017-03-01

    Full Text Available Most existing culture media for cardiac differentiation of human pluripotent stem cells (hPSCs contain significant amounts of albumin. For clinical transplantation applications of hPSC-derived cardiomyocytes (hPSC-CMs, culturing cells in an albumin containing environment raises the concern of pathogen contamination and immunogenicity to the recipient patients. In addition, batch-to-batch variation of albumin may cause the inconsistent of hPSC cardiac differentiation. Here, we demonstrated that antioxidants l-ascorbic acid, trolox, N-acetyl-l-cysteine (NAC and sodium pyruvate could functionally substitute albumin in the culture medium, and formulated an albumin-free, chemical-defined medium (S12 medium. We showed that S12 medium could support efficient hPSC cardiac differentiation with significantly improved reproducibility, and maintained long-term culture of hPSC-CMs. Furthermore, under chemical-defined and albumin-free conditions, human-induced pluripotent stem cells (hiPSCs were established, and differentiated into highly homogenous atrial and ventricular myocytes in a scalable fashion with normal electrophysiological properties. Finally, we characterized the activity of three typical cardiac ion channels of those cells, and demonstrated that hPSC-derived ventricular cardiomyocytes (hPSC-vCMs were suitable for drug cardiac safety evaluation. In summary, this simplified, chemical-defined and albumin-free culture medium supports efficient generation and maintaining of hPSC-CMs and facilitates both research and clinical applications of these cells.

  3. Prevention of adenosine A2A receptor activation diminishes beat-to-beat alternation in human atrial myocytes.

    Science.gov (United States)

    Molina, Cristina E; Llach, Anna; Herraiz-Martínez, Adela; Tarifa, Carmen; Barriga, Montserrat; Wiegerinck, Rob F; Fernandes, Jacqueline; Cabello, Nuria; Vallmitjana, Alex; Benitéz, Raúl; Montiel, José; Cinca, Juan; Hove-Madsen, Leif

    2016-01-01

    Atrial fibrillation (AF) has been associated with increased spontaneous calcium release from the sarcoplasmic reticulum and linked to increased adenosine A2A receptor (A2AR) expression and activation. Here we tested whether this may favor atrial arrhythmogenesis by promoting beat-to-beat alternation and irregularity. Patch-clamp and confocal calcium imaging was used to measure the beat-to-beat response of the calcium current and transient in human atrial myocytes. Responses were classified as uniform, alternating or irregular and stimulation of Gs-protein coupled receptors decreased the frequency where a uniform response could be maintained from 1.0 ± 0.1 to 0.6 ± 0.1 Hz; p < 0.01 for beta-adrenergic receptors and from 1.4 ± 0.1 to 0.5 ± 0.1 Hz; p < 0.05 for A2ARs. The latter was linked to increased spontaneous calcium release and after-depolarizations. Moreover, A2AR activation increased the fraction of non-uniformly responding cells in HL-1 myocyte cultures from 19 ± 3 to 51 ± 9 %; p < 0.02, and electrical mapping in perfused porcine atria revealed that adenosine induced electrical alternans at longer cycle lengths, doubled the fraction of electrodes showing alternation, and increased the amplitude of alternations. Importantly, protein kinase A inhibition increased the highest frequency where uniform responses could be maintained from 0.84 ± 0.12 to 1.86 ± 0.11 Hz; p < 0.001 and prevention of A2AR-activation with exogenous adenosine deaminase selectively increased the threshold from 0.8 ± 0.1 to 1.2 ± 0.1 Hz; p = 0.001 in myocytes from patients with AF. In conclusion, A2AR-activation promotes beat-to-beat irregularities in the calcium transient in human atrial myocytes, and prevention of A2AR activation may be a novel means to maintain uniform beat-to-beat responses at higher beating frequencies in patients with atrial fibrillation.

  4. Clinical Benefit of Ablating Localized Sources for Human Atrial Fibrillation: The Indiana University FIRM Registry.

    Science.gov (United States)

    Miller, John M; Kalra, Vikas; Das, Mithilesh K; Jain, Rahul; Garlie, Jason B; Brewster, Jordan A; Dandamudi, Gopi

    2017-03-14

    Mounting evidence shows that localized sources maintain atrial fibrillation (AF). However, it is unclear in unselected "real-world" patients if sources drive persistent atrial fibrillation (PeAF), long-standing persistent atrial fibrillation (LPeAF), or paroxysmal atrial fibrillation (PAF); if right atrial sites are important; and what the long-term success of source ablation is. The aim of this study was to analyze the role of rotors and focal sources in a large academic registry of consecutive patients undergoing source mapping for AF. One hundred seventy consecutive patients (mean age 59 ± 12 years, 79% men) with PAF (37%), PeAF (31%), or LPeAF (32%). Of these, 73 (43%) had undergone at least 1 prior ablation attempt (mean 1.9 ± 0.8; range: 1 to 4). Focal impulse and rotor modulation (FIRM) with an endocardial basket catheter was used in all cases. FIRM analysis revealed sources in the right atrium in 85% of patients (1.8 ± 1.3) and in the left atrium in 90% of patients (2.0 ± 1.3). FIRM ablation terminated AF to sinus rhythm or atrial flutter or tachycardia in 59% (PAF), 37% (PeAF), and 19% (LPeAF) of patients, with 15 of 67 terminations due to right atrial ablation. On follow-up, freedom from AF after a single FIRM procedure for the entire series was 95% (PAF), 83% (PeAF), and 82% (LPeAF) at 1 year and freedom from all atrial arrhythmias was 77% (PAF), 75% (PeAF), and 57% (LPeAF). In the Indiana University FIRM registry, FIRM-guided ablation produced high single-procedure success, mostly in patients with nonparoxysmal AF. Data from mapping, acute terminations, and outcomes strongly support the mechanistic role of biatrial rotors and focal sources in maintaining AF in diverse populations. Randomized trials of FIRM-guided ablation and mechanistic studies to determine how rotors form, progress, and regress are needed. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  5. Pulmonary vein and atrial wall pathology in human total anomalous pulmonary venous connection

    NARCIS (Netherlands)

    Douglas, Yvonne L.; Jongbloed, Monique R. M.; den Hartog, Wietske C. E.; Bartelings, Margot M.; Bogers, Ad J. J. C.; Ebels, Tjark; DeRuiter, Marco C.; Gittenberger-de Groot, Adriana C.

    2009-01-01

    Background: Normally, the inside of the left atrial (LA) body and pulmonary veins (PVs) is lined by vessel wall tissue covered by myocardium. In total anomalous pulmonary venous connection (TAPVC), no connection of the PVs with the LA body exists. These veins have an increased incidence of PV

  6. Atrial Electrogram Fractionation Distribution before and after Pulmonary Vein Isolation in Human Persistent Atrial Fibrillation—A Retrospective Multivariate Statistical Analysis

    Science.gov (United States)

    Almeida, Tiago P.; Chu, Gavin S.; Li, Xin; Dastagir, Nawshin; Tuan, Jiun H.; Stafford, Peter J.; Schlindwein, Fernando S.; Ng, G. André

    2017-01-01

    Purpose: Complex fractionated atrial electrograms (CFAE)-guided ablation after pulmonary vein isolation (PVI) has been used for persistent atrial fibrillation (persAF) therapy. This strategy has shown suboptimal outcomes due to, among other factors, undetected changes in the atrial tissue following PVI. In the present work, we investigate CFAE distribution before and after PVI in patients with persAF using a multivariate statistical model. Methods: 207 pairs of atrial electrograms (AEGs) were collected before and after PVI respectively, from corresponding LA regions in 18 persAF patients. Twelve attributes were measured from the AEGs, before and after PVI. Statistical models based on multivariate analysis of variance (MANOVA) and linear discriminant analysis (LDA) have been used to characterize the atrial regions and AEGs. Results: PVI significantly reduced CFAEs in the LA (70 vs. 40%; P PVI that remained fractionated after PVI (31% of the collected points); (ii) fractionated that converted to normal (39%); (iii) normal prior to PVI that became fractionated (9%) and; (iv) normal that remained normal (21%). Individually, the attributes failed to distinguish these LA regions, but multivariate statistical models were effective in their discrimination (P PVI, while others are affected by it. Although, traditional methods were unable to identify these different regions, the proposed multivariate statistical model discriminated LA regions resistant to PVI from those affected by it without prior ablation information. PMID:28883795

  7. Atrial Electrogram Fractionation Distribution before and after Pulmonary Vein Isolation in Human Persistent Atrial Fibrillation-A Retrospective Multivariate Statistical Analysis.

    Science.gov (United States)

    Almeida, Tiago P; Chu, Gavin S; Li, Xin; Dastagir, Nawshin; Tuan, Jiun H; Stafford, Peter J; Schlindwein, Fernando S; Ng, G André

    2017-01-01

    Purpose: Complex fractionated atrial electrograms (CFAE)-guided ablation after pulmonary vein isolation (PVI) has been used for persistent atrial fibrillation (persAF) therapy. This strategy has shown suboptimal outcomes due to, among other factors, undetected changes in the atrial tissue following PVI. In the present work, we investigate CFAE distribution before and after PVI in patients with persAF using a multivariate statistical model. Methods: 207 pairs of atrial electrograms (AEGs) were collected before and after PVI respectively, from corresponding LA regions in 18 persAF patients. Twelve attributes were measured from the AEGs, before and after PVI. Statistical models based on multivariate analysis of variance (MANOVA) and linear discriminant analysis (LDA) have been used to characterize the atrial regions and AEGs. Results: PVI significantly reduced CFAEs in the LA (70 vs. 40%; P multivariate statistical models were effective in their discrimination (P multivariate statistical model discriminated LA regions resistant to PVI from those affected by it without prior ablation information.

  8. Recurrence quantification analysis applied to spatiotemporal pattern analysis in high-density mapping of human atrial fibrillation

    NARCIS (Netherlands)

    Zeemering, Stef; Bonizzi, Pietro; Maesen, Bart; Peeters, Ralf; Schotten, Ulrich

    2015-01-01

    Spatiotemporal complexity of atrial fibrillation (AF) patterns is often quantified by annotated intracardiac contact mapping. We introduce a new approach that applies recurrence plot (RP) construction followed by recurrence quantification analysis (RQA) to epicardial atrial electrograms, recorded wi

  9. Prostacyclins have no direct inotropic effect on isolated atrial strips from the normal and pressure-overloaded human right heart

    DEFF Research Database (Denmark)

    Holmboe, Sarah; Andersen, Asger; Vibjerg Jensen, Rebekka

    2017-01-01

    mimetics in the normal and the pressure-overloaded human right atrium. Trabeculae from the right atrium were collected during surgery from chronic thromboembolic pulmonary hypertension (CTEPH) patients with pressure-overloaded right hearts, undergoing pulmonary thromboendarterectomy (n = 10) and from...... to elicit a reference inotropic response. The force of contraction was measured continuously. The expression of prostanoid receptors was explored through quantitative polymerase chain reaction (qPCR). Iloprost, treprostinil, epoprostenol, or MRE-269 did not alter force of contraction in any...... expression of the different prostanoid receptors in the human atrium. In conclusion, prostacyclin mimetics did not increase the force of contraction of human atrial trabeculae from the normal or the pressure-overloaded right heart. These data suggest that prostacyclin mimetics have no direct inotropic...

  10. Maximal heart rate does not limit cardiovascular capacity in healthy humans: insight from right atrial pacing during maximal exercise.

    Science.gov (United States)

    Munch, G D W; Svendsen, J H; Damsgaard, R; Secher, N H; González-Alonso, J; Mortensen, S P

    2014-01-15

    In humans, maximal aerobic power (VO2 max ) is associated with a plateau in cardiac output (Q), but the mechanisms regulating the interplay between maximal heart rate (HRmax) and stroke volume (SV) are unclear. To evaluate the effect of tachycardia and elevations in HRmax on cardiovascular function and capacity during maximal exercise in healthy humans, 12 young male cyclists performed incremental cycling and one-legged knee-extensor exercise (KEE) to exhaustion with and without right atrial pacing to increase HR. During control cycling, Q and leg blood flow increased up to 85% of maximal workload (WLmax) and remained unchanged until exhaustion. SV initially increased, plateaued and then decreased before exhaustion (P rate pressure product and RAP (P heart can be paced to a higher HR than observed during maximal exercise, suggesting that HRmax and myocardial work capacity do not limit VO2 max in healthy individuals. A limited left ventricular filling and possibly altered contractility reduce SV during atrial pacing, whereas a plateau in LVFP appears to restrict Q close to VO2 max .

  11. Excitation-Contraction Coupling between Human Atrial Myocytes with Fibroblasts and Stretch Activated Channel Current: A Simulation Study

    Directory of Open Access Journals (Sweden)

    Heqing Zhan

    2013-01-01

    Full Text Available Myocytes have been regarded as the main objectives in most cardiac modeling studies and attracted a lot of attention. Connective tissue cells, such as fibroblasts (Fbs, also play crucial role in cardiac function. This study proposed an integrated myocyte-Isac-Fb electromechanical model to investigate the effect of Fbs and stretch activated ion channel current (Isac on cardiac electrical excitation conduction and mechanical contraction. At the cellular level, an active Fb model was coupled with a human atrial myocyte electrophysiological model (including Isac and a mechanical model. At the tissue level, electrical excitation conduction was coupled with an elastic mechanical model, in which finite difference method (FDM was used to solve the electrical excitation equations, while finite element method (FEM was used for the mechanics equations. The simulation results showed that Fbs and Isac coupling caused diverse effects on action potential morphology during repolarization, depolarized the resting membrane potential of the human atrial myocyte, slowed down wave propagation, and decreased strains in fibrotic tissue. This preliminary simulation study indicates that Fbs and Isac have important implications for modulating cardiac electromechanical behavior and should be considered in future cardiac modeling studies.

  12. Recurrent epiploic appendagitis mimicking appendicitis and cholecystitis

    Science.gov (United States)

    Hearne, Christopher B.; Taboada, Jorge

    2017-01-01

    Epiploic appendagitis (EA) is a rare cause of acute abdominal pain caused by inflammation of an epiploic appendage. It has a nonspecific clinical presentation that may mimic other acute abdominal pathologies on physical exam, such as appendicitis, diverticulitis, or cholecystitis. However, EA is usually benign and self-limiting and can be treated conservatively. We present the case of a patient with two episodes of EA, the first mimicking acute appendicitis and the second mimicking acute cholecystitis. Although recurrence of EA is rare, it should be part of the differential diagnosis of acute, localized abdominal pain. A correct diagnosis of EA will prevent unnecessary hospitalization, antibiotic use, and surgical procedures. PMID:28127129

  13. Percutaneous atrial appendage occlusion for stroke prevention in patients with atrial fibrillation

    DEFF Research Database (Denmark)

    Munkholm-Larsen, Stine; Cao, Christopher; Yan, Tristan D;

    2012-01-01

    databases. Fourteen studies were identified for evaluation. Overall, implantation was successful in 93% of all cases. Periprocedural mortality and stroke rates were 1.1% and 0.6%, respectively. The incidences of pericardial effusion/cardiac tamponade and device embolisation were 4% and 0.7%, respectively...

  14. Percutaneous left atrial appendage occlusion for stroke prevention in atrial fibrillation

    DEFF Research Database (Denmark)

    De Backer, O; Arnous, S; Ihlemann, N

    2014-01-01

    prevention in patients with AF with an increased stroke risk. However, there are several obstacles to long-term OAC therapy, including the risk of serious bleeding, several drug-drug interactions and the need for frequent blood testing. Although newer oral anticoagulants have been developed, these drugs also...

  15. Left atrial appendage occlusion versus standard medical care in patients with atrial fibrillation and intracerebral hemorrhage

    DEFF Research Database (Denmark)

    Nielsen-Kudsk, Jens Erik; Johnsen, Søren Paaske; Wester, Per

    2017-01-01

    countries with AF and previous ICH who underwent LAAO using the Amplatzer Cardiac Plug or the Amplatzer Amulet were compared to a propensity score matched group of 151 patients receiving standard medical therapy. The two groups were matched so that their risks for stroke and bleeding were similar (CHA2DS2...

  16. Is percutaneous closure of the left atrial appendage comparable to anticoagulants for atrial fibrillation?

    Directory of Open Access Journals (Sweden)

    Thomas Uslar

    2015-08-01

    Full Text Available La anticoagulación oral constituye el tratamiento estándar para la prevención de accidentes vasculares encefálicos en la mayoría de los pacientes con fibrilación auricular. Sin embargo, conlleva un riesgo importante de sangrado, por lo que han aparecido nuevas alternativas terapéuticas, como el cierre percutáneo de la orejuela de la aurícula izquierda. No existe claridad sobre si este procedimiento es comparable a la terapia convencional con tratamiento anticoagulante. Utilizando la base de datos Epistemonikos, la cual es mantenida mediante búsquedas en 30 bases de datos, identificamos tres revisiones sistemáticas que incluyen sólo un estudio aleatorizado pertinente. Realizamos un resumen de los resultados utilizando el método GRADE. Se concluye que el cierre percutáneo de la orejuela de la aurícula izquierda podría disminuir el número total de accidentes vasculares y la mortalidad, pero la certeza de la evidencia es baja. Existe incertidumbre sobre su efecto sobre otros desenlaces porque la certeza de la evidencia es muy baja.

  17. Atrial Electrogram Fractionation Distribution before and after Pulmonary Vein Isolation in Human Persistent Atrial Fibrillation—A Retrospective Multivariate Statistical Analysis

    Directory of Open Access Journals (Sweden)

    Tiago P. Almeida

    2017-08-01

    Full Text Available Purpose: Complex fractionated atrial electrograms (CFAE-guided ablation after pulmonary vein isolation (PVI has been used for persistent atrial fibrillation (persAF therapy. This strategy has shown suboptimal outcomes due to, among other factors, undetected changes in the atrial tissue following PVI. In the present work, we investigate CFAE distribution before and after PVI in patients with persAF using a multivariate statistical model.Methods: 207 pairs of atrial electrograms (AEGs were collected before and after PVI respectively, from corresponding LA regions in 18 persAF patients. Twelve attributes were measured from the AEGs, before and after PVI. Statistical models based on multivariate analysis of variance (MANOVA and linear discriminant analysis (LDA have been used to characterize the atrial regions and AEGs.Results: PVI significantly reduced CFAEs in the LA (70 vs. 40%; P < 0.0001. Four types of LA regions were identified, based on the AEGs characteristics: (i fractionated before PVI that remained fractionated after PVI (31% of the collected points; (ii fractionated that converted to normal (39%; (iii normal prior to PVI that became fractionated (9% and; (iv normal that remained normal (21%. Individually, the attributes failed to distinguish these LA regions, but multivariate statistical models were effective in their discrimination (P < 0.0001.Conclusion: Our results have unveiled that there are LA regions resistant to PVI, while others are affected by it. Although, traditional methods were unable to identify these different regions, the proposed multivariate statistical model discriminated LA regions resistant to PVI from those affected by it without prior ablation information.

  18. TRIF promotes angiotensin II-induced cross-talk between fibroblasts and macrophages in atrial fibrosis

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiao-Qing; Zhang, Dao-Liang [Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai (China); Zhang, Ming-Jian; Guo, Meng; Zhan, Yang-Yang; Liu, Fang [National Key Laboratory of Medical Immunology, Second Military Medical University, Shanghai (China); Jiang, Wei-Feng; Zhou, Li [Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai (China); Zhao, Liang, E-mail: zhaol_zg@163.com [Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai (China); Wang, Quan-Xing, E-mail: wqxejd@126.com [National Key Laboratory of Medical Immunology, Second Military Medical University, Shanghai (China); Liu, Xu, E-mail: liuxu_xk@163.com [Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai (China)

    2015-08-14

    Aims: Atrial fibroblasts and macrophages have long been thought to participate in atrial fibrillation (AF). However, which specific mediator may regulate the interaction between them remains unclear. Methods and results: We provided the evidence for the involvement of Toll/IL-1 receptor domain-containing adaptor inducing IFN-β (TRIF), an important inflammation-related molecule, in the pathophysiology of AF. Patients with AF showed higher levels of angiotensin II (AngII) and TRIF expression and larger number of macrophages infiltration in left atria appendage than individuals with sinus rhythm (SR). In the cell study, AngII induced chemokines expressions in mouse atrial fibroblasts and AngII-stimulated atrial fibroblasts induced the chemotaxis of macrophages, which were reduced by losartan and TRIF siRNA. Meanwhile, AngII-stimulated atrial fibroblasts proliferation was enhanced by macrophages. Conclusions: Our data demonstrated that TRIF may be a crucial factor promoting the interaction between atrial fibroblasts and macrophages, leading to atrial fibrosis. - Highlights: • Compared with SR, AF showed higher TRIF expression in left atrial appendage. • TRIF siRNA reversed macrophage chemotaxis induced by AngII-treated fibroblast. • TRIF siRNA reversed chemokines expressions induced by AngII in fibroblast. • AngII-stimulated atrial fibroblast proliferation was enhanced by macrophage.

  19. Novel Mutations in the Transcriptional Activator Domain of the Human TBX20 in Patients with Atrial Septal Defect

    Directory of Open Access Journals (Sweden)

    Irma Eloisa Monroy-Muñoz

    2015-01-01

    Full Text Available Background. The relevance of TBX20 gene in heart development has been demonstrated in many animal models, but there are few works that try to elucidate the effect of TBX20 mutations in human congenital heart diseases. In these studies, all missense mutations associated with atrial septal defect (ASD were found in the DNA-binding T-box domain, none in the transcriptional activator domain. Methods. We search for TBX20 mutations in a group of patients with ASD or ventricular septal defect (VSD using the High Resolution Melting (HRM method and DNA sequencing. Results. We report three missense mutations (Y309D, T370O, and M395R within the transcriptional activator domain of human TBX20 that were associated with ASD. Conclusions. This is the first association of TBX20 transcriptional activator domain missense mutations with ASD. These findings could have implications for diagnosis, genetic screening, and patient follow-up.

  20. Protein analysis of atrial fibrosis via label-free proteomics in chronic atrial fibrillation patients with mitral valve disease.

    Directory of Open Access Journals (Sweden)

    Peide Zhang

    Full Text Available BACKGROUND: Atrial fibrosis, as a hallmark of atrial structure remodeling, plays an important role in maintenance of chronic atrial fibrillation, but interrelationship of atrial fibrosis and atrial fibrillation is uncertain. Label-free proteomics can implement high throughput screening for finding and analyzing pivotal proteins related to the disease.. Therefore, we used label-free proteomics to explore and analyze differentially proteins in chronic atrial fibrillation patients with mitral valve disease. METHODS: Left and right atrial appendages obtained from patients with mitral valve disease were both in chronic atrial fibrillation (CAF, AF≥6 months, n = 6 and in sinus rhythm (SR, n = 6. One part of the sample was used for histological analysis and fibrosis quantification; other part were analyzed by label-free proteomic combining liquid chromatography with mass spectrometry (LC-MS, we utilized bioinformatics analysis to identify differential proteins. RESULTS: Degree of atrial fibrosis was higher in CAF patients than that of SR patients. 223 differential proteins were detected between two groups. These proteins mainly had vital functions such as cell proliferation, stress response, focal adhesion apoptosis. We evaluated that serine/threonine protein kinase N2 (PKN2, dermatopontin (DP, S100 calcium binding protein B (S100B, protein tyrosine kinase 2 (PTK2 and discoidin domain receptor tyrosine kinase 2 (DDR2 played important roles in fibrotic process related to atrial fibrillation. CONCLUSION: The study presented differential proteins responsible for atrial fibrosis in chronic atrial fibrillation patients through label-free proteomic analysis. We assessed some vital proteins including their characters and roles. These findings may open up new realm for mechanism research of atrial fibrillation.

  1. Association of left atrial endothelin-1 with atrial rhythm, size, and fibrosis in patients with structural heart disease.

    Science.gov (United States)

    Mayyas, Fadia; Niebauer, Mark; Zurick, Andrew; Barnard, John; Gillinov, A Marc; Chung, Mina K; Van Wagoner, David R

    2010-08-01

    Atrial fibrillation (AF) promotes atrial remodeling and can develop secondary to heart failure or mitral valve disease. Cardiac endothelin-1 (ET-1) expression responds to wall stress and can promote myocyte hypertrophy and interstitial fibrosis. We tested the hypothesis that atrial ET-1 is elevated in AF and is associated with AF persistence. Left atrial appendage tissue was studied from coronary artery bypass graft, valve repair, and/or Maze procedure in patients in sinus rhythm with no history of AF (SR, n=21), with history of AF but in SR at surgery (AF/SR, n=23), and in AF at surgery (AF/AF, n=32). The correlation of LA size with atrial protein and mRNA expression of ET-1 and ET-1 receptors (ETAR and ETBR) was evaluated. LA appendage ET-1 content was higher in AF/AF than in SR, but receptor levels were similar. Immunostaining revealed that ET-1 and its receptors were present both in atrial myocytes and in fibroblasts. ET-1 content was positively correlated with LA size, heart failure, AF persistence, and severity of mitral regurgitation. Multivariate analysis confirmed associations of ET-1 with AF, hypertension, and LA size. LA size was associated with ET-1 and MR severity. ET-1 mRNA levels were correlated with genes involved in cardiac dilatation, hypertrophy, and fibrosis. Elevated atrial ET-1 content is associated with increased LA size, AF rhythm, hypertension, and heart failure. ET-1 is associated with atrial dilatation, fibrosis, and hypertrophy and probably contributes to AF persistence. Interventions that reduce atrial ET-1 expression and/or block its receptors may slow AF progression.

  2. Atrial distension, arterial pulsation, and vasopressin release during negative pressure breathing in humans

    DEFF Research Database (Denmark)

    Pump, B; Damgaard, M; Gabrielsen, A

    2001-01-01

    in eight healthy males, we tested the hypothesis that with similar increases in LA diameter, suppression of AVP release is dependent on the degree of increase in PP. LA diameter increased similarly during the posture change and negative pressure breathing (-9 to -24 mmHg) from between 30 and 31 +/- 1 to 34......During an antiorthostatic posture change, left atrial (LA) diameter and arterial pulse pressure (PP) increase, and plasma arginine vasopressin (AVP) is suppressed. By comparing the effects of a 15-min posture change from seated to supine with those of 15-min seated negative pressure breathing...... +/- 1 mm (P breathing from 36 +/- 3 to 42 +/- 3 mmHg (P

  3. Atrial distension, arterial pulsation, and vasopressin release during negative pressure breathing in humans

    DEFF Research Database (Denmark)

    Pump, B; Damgaard, M; Gabrielsen, A;

    2001-01-01

    During an antiorthostatic posture change, left atrial (LA) diameter and arterial pulse pressure (PP) increase, and plasma arginine vasopressin (AVP) is suppressed. By comparing the effects of a 15-min posture change from seated to supine with those of 15-min seated negative pressure breathing...... in eight healthy males, we tested the hypothesis that with similar increases in LA diameter, suppression of AVP release is dependent on the degree of increase in PP. LA diameter increased similarly during the posture change and negative pressure breathing (-9 to -24 mmHg) from between 30 and 31 +/- 1 to 34...... +/- 1 mm (P breathing from 36 +/- 3 to 42 +/- 3 mmHg (P

  4. Role of the MAPKs/TGF-β1/TRAF6 signaling pathway in atrial fibrosis of patients with chronic atrial fibrillation and rheumatic mitral valve disease.

    Science.gov (United States)

    Zhang, Daoliang; Liu, Xu; Chen, Xiaoqing; Gu, Jun; Li, Feng; Zhang, Wei; Zheng, Yue

    2014-01-01

    Atrial remodeling is involved in atrial fibrillation (AF), and atrial fibrosis is an important marker of atrial remodeling. On the basis of our previous animal studies of the mitogen-activated protein kinases (MAPKs)/transforming growth factor β1 (TGF-β1)/tumor necrosis factor pathway in atrial fibrosis, we undertook investigation of this signaling pathway in atrial fibrosis of patients with chronic AF (CAF) and rheumatic mitral valve disease. Fifty-six rheumatic mitral valve disease patients were divided into CAF (course of AF >12 months) and sinus rhythm (SR) groups. Left atrial appendage tissue was collected during heart surgery, and pathological examination was done to evaluate atrial fibrosis. Protein and mRNA expression of TGF-β1, TRAF6 and connective tissue growth factor (CTGF) and protein expression of phosphorylated MAPKs and TGF-β-activated kinase 1 (TAK1) were measured. Histological examination revealed that the severity of atrial fibrosis in CAF patients was significantly higher, mRNA and protein expression of TGF-β1, TRAF6 and CTGF in CAF were significantly increased, and the protein expression of phosphorylated MAPKs and TAK1 was significantly increased in CAF compared to SR patients. The MAPKs/TGF-β1/TRAF6 signaling pathway is involved in atrial fibrosis of CAF patients, and TRAF6 may become a new target for the treatment of atrial fibrosis.

  5. Atrial Tachycardias Arising from Ablation of Atrial Fibrillation: A Proarrhythmic Bump or an Antiarrhythmic Turn?

    Directory of Open Access Journals (Sweden)

    Ashok J. Shah

    2010-01-01

    Full Text Available The occurrence of atrial tachycardias (AT is a direct function of the volume of atrial tissue ablated in the patients with atrial fibrillation (AF. Thus, the incidence of AT is highest in persistent AF patients undergoing stepwise ablation using the strategic combination of pulmonary vein isolation, electrogram based ablation and left atrial linear ablation. Using deductive mapping strategy, AT can be divided into three clinical categories viz. the macroreentry, the focal and the newly described localized reentry all of which are amenable to catheter ablation with success rate of 95%. Perimitral, roof dependent and cavotricuspid isthmus dependent AT involve large reentrant circuits which can be successfully ablated at the left mitral isthmus, left atrial roof and tricuspid isthmus respectively. Complete bidirectional block across the sites of linear ablation is a necessary endpoint. Focal and localized reentrant AT commonly originate from but are not limited to the septum, posteroinferior left atrium, venous ostia, base of the left atrial appendage and left mitral isthmus and they respond quickly to focal ablation. AT not only represents ablation-induced proarrhythmia but also forms a bridge between AF and sinus rhythm in longstanding AF patients treated successfully with catheter ablation.

  6. Alpha-human atrial natriuretic polypeptide (. cap alpha. -hANP) specific binding sites in bovine adrenal gland

    Energy Technology Data Exchange (ETDEWEB)

    Higuchi, K.; Nawata, H.; Kato, K.I.; Ibayashi, H.; Matsuo, H.

    1986-06-13

    The effects of synthetic ..cap alpha..-human atrial natriuretic polypeptide (..cap alpha..-hANP) on steroidogenesis in bovine adrenocortical cells in primary monolayer culture were investigated. ..cap alpha..-hANP did not inhibit basal aldosterone secretion. ..cap alpha..-hANP induced a significant dose-dependent inhibition of basal levels of cortisol and dehydroepiandrosterone (DHEA) secretion and also of aCTH (10/sup -8/M)-stimulated increases in aldosterone, cortisol and DHEA secretion. Visualization of (/sup 125/I) ..cap alpha..-hANP binding sites in bovine adrenal gland by an in vitro autoradiographic technique demonstrated that these sites were highly localized in the adrenal cortex, especially the zona glomerulosa. These results suggest that the adrenal cortex may be a target organ for direct receptor-mediated actions of ..cap alpha..-hANP.

  7. Spatial relationship of organized rotational and focal sources in human atrial fibrillation to autonomic ganglionated plexi.

    Science.gov (United States)

    Baykaner, Tina; Zografos, Theodoros A; Zaman, Junaid A B; Pantos, Ioannis; Alhusseini, Mahmood; Navara, Rachita; Krummen, David E; Narayan, Sanjiv M; Katritsis, Demosthenes G

    2017-08-01

    One approach to improve ablation for atrial fibrillation (AF) is to focus on physiological targets including focal or rotational sources or ganglionic plexi (GP). However, the spatial relationship between these potential mechanisms has never been studied. We tested the hypothesis that rotors and focal sources for AF may co-localize with ganglionated plexi (GP). We prospectively identified locations of AF rotors and focal sources, and correlated these to GP sites in 97 consecutive patients (age 59.9±11.4, 73% persistent AF). AF was recorded with 64-pole catheters with activation/phase mapping, and related to anatomic GP sites on electroanatomic maps. AF sources arose in 96/97 (99%) patients for 2.6±1.4 sources per patient (left atrium: 1.7±0.9 right atrium: 1.1±0.8), each with an area of 2-3cm(2). On area analyses, the probability of an AF source randomly overlapping a GP area was 26%. Left atrial sources were seen in 94 (97%) patients, in whom ≥1 source co-localized with GP in 75 patients (80%; psources were more likely to colocalize with left vs right GPs (p65, diabetes; psources in the left atrium often colocalize with regions of autonomic innervation. Studies should define if the role of AF sources differs by their anatomical location. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. CT features of primary epiploic appendagitis

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Keng Sin [Department of Oncologic Imaging, National Cancer Centre, 11 Hospital Drive, Singapore 169610 (Singapore)]. E-mail: ngkeng@gmail.com; Tan, Andrew Gee Seng [Department of Radiology, Changi General Hospital, 2 Simei Street 3, Singapore 529889, Singapore. (Singapore); Chen, Kevin K' o Wen [Department of Diagnostic Radiology, Singapore General Hospital, Outram Road, Singapore 169608 (Singapore); Wong, Siew Kune [Department of Diagnostic Radiology, Singapore General Hospital, Outram Road, Singapore 169608 (Singapore); Tan, How Ming [Department of Diagnostic Radiology, Singapore General Hospital, Outram Road, Singapore 169608 (Singapore)

    2006-08-15

    Objective: The aim of this study is to describe the computed tomography (CT) findings of primary epiploic appendagitis (PEA). Methods: We reviewed the clinical records and CT images of 14 consecutive patients in Singapore who presented with acute abdominal pain from July 2000 to April 2004 and had radiological signs of PEA. Results: Hyperattenuated ring with adjacent fat stranding was present in all the patients. The central high attenuation dot was seen in 42.9% (6/14) of the patients. We observed a lobulated fatty mass in 21.4% (3/14) of our patients. All patients recovered during clinical follow-up. Conclusions: We believe the lobulated appearance of PEA is due to two or more, contiguous infarcted epiploic appendages lying in close proximity. This appearance further aids in the diagnosis of PEA and helps differentiates the condition from omental infarction. Recognizing the CT signs of PEA should allow a confident diagnosis and avoid unnecessary surgery.

  9. Primary epiploic appendagitis: from A to Z

    Directory of Open Access Journals (Sweden)

    Iyad A Issa

    2010-07-01

    Full Text Available Iyad A Issa1, Mohamad-Tarek Berjaoui2, Wajdi S Hamdan21Department of Gastroenterology and Hepatology, Rafik Hariri University Hospital, Beirut, Lebanon; 2Department of General Surgery, Rafik Hariri University Hospital, Beirut, LebanonAbstract: Epiploic appendagitis is a rare and uncommon diagnosis that is frequently unknown to clinicians. Inflammation is usually acute and causes abrupt symptoms, but once the diagnosis is accurately made, most patients respond to pain control and conservative management. We report the case of a young woman presenting with acute primary epiploic appendagitis of the right colon. The inflammatory mass was unusually large and occurred a few months after surgery for gastric bypass. This case will give us the opportunity to discuss the clinical presentation of this disease, as well as the potential associations and risk factors and the means for adequate diagnosis and treatment.Keywords: appendices, epiploicae, bypass surgery, inflammation, computed tomography

  10. Mean corpuscular volume and red cell distribution width as predictors of left atrial stasis in patients with non-valvular atrial fibrillation.

    Science.gov (United States)

    Providência, Rui; Ferreira, Maria João; Gonçalves, Lino; Faustino, Ana; Paiva, Luís; Fernandes, Andreia; Barra, Sérgio; Pimenta, Joana; Leitão-Marques, António M

    2013-01-01

    The role of erythrocyte indexes for the prediction of left atrial stasis, assessed by transesophageal echocardiography in patients with non-valvular atrial fibrillation, has not been previously clarified. Single center cross-sectional study comprising 247 consecutive patients admitted to the emergency department due to symptomatic atrial fibrillation and undergoing transesophageal echocardiogram evaluation for exclusion of left atrial appendage thrombus (LAAT) before cardioversion. All patients had a complete blood count performed up to 12 hours prior to the transesophageal echocardiogram. Markers of left atrial stasis were sought: LAAT, dense spontaneous echocardiographic contrast (DSEC) and low flow velocities (LFV) in the left atrial appendage. Erythrocyte indexes' accuracy for detecting transesophageal echocardiogram changes was evaluated through receiver operating curve analysis. Binary logistic multivariate analysis, using solely erythrocyte indexes and in combination with other variables (i.e. CHADS2, CHA2DS2VASc classifications and left ventricle ejection fraction), was used for transesophageal echocardiogram endpoints prediction. LAAT was found in 8.5%, DSEC in 26.1% and LFV in 12.1%. Mean corpuscular volume and red cell distribution width were independent predictors of LAAT and DSEC. Despite adding incremental predictive value to each other, when clinical risk factors from CHADS2 and CHA2DS2VASc classifications and left ventricle ejection fraction were added to the models, only mean corpuscular volume remained an independent predictor of LAAT and DSEC. These findings suggest that mean corpuscular volume and red cell distribution width may be linked to left atrial stasis markers.

  11. Primary epiploic appendagitis: US and CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Molla, E.; Ripolles, T.; Martinez, M.J.; Morote, V. [Department of Radiology, Hospital Dr. Peset, Valencia (Spain); Rosello-Sastre, E. [Department of Pathology, Hospital Dr. Peset, Valencia (Spain)

    1998-03-27

    A retrospective review is presented of seven cases of epiploic appendagitis, with surgical confirmation in one case. The main clinico-analytical data and the US and CT findings are described, as well as the histopathologic features in the sole case that underwent surgical resection. We also calculated the frequency of this entity in patients undergoing emergency abdominal US on clinical suspicion of diverticulitis. In all seven cases the clinico-analytical evidence was nonspecific (localized acute abdominal pain and slight leukocytosis), mimicking in six cases the clinical presentation of sigmoid diverticulitis and in one case that of acute appendicitis. US imaging findings were characteristic: a hyperechoic mass localized under the point of maximum pain, adjacent to the anterior peritoneal wall and fixed during deep breathing. In none of the cases did color Doppler US show flow. CT findings were also typical and showed a mass with a peripheral hyperattenuated rim surrounding an area of fatty attenuation. Overall 7.1 % of patients investigated to exclude sigmoid diverticulitis finally showed findings of primary epiploic appendagitis. Primary epiploic appendagitis thus shows characteristic US and CT findings that allow its diagnosis and follow-up. This entity is much more frequent than previously reported, especially in patients referred for US to exclude sigmoid diverticulitis. (orig.) With 4 figs., 14 refs.

  12. Accessory left atrial diverticulae: contractile properties depicted with 64-slice cine-cardiac CT.

    LENUS (Irish Health Repository)

    Killeen, Ronan P

    2012-02-01

    To assess the contractility of accessory left atrial appendages (LAAs) using multiphasic cardiac CT. We retrospectively analyzed the presence, location, size and contractile properties of accessory LAAs using multiphasic cardiac 64-slice CT in 102 consecutive patients (63 males, 39 females, mean age 57). Multiplanar reformats were used to create image planes in axial oblique, sagittal oblique and coronal oblique planes. For all appendages with an orifice diameter >or= 10 mm, axial and sagittal diameters and appendage volumes were recorded in atrial diastole and systole. Regression analysis was performed to assess which imaging appearances best predicted accessory appendage contractility. Twenty-three (23%) patients demonstrated an accessory LAA, all identified along the anterior LA wall. Dimensions for axial oblique (AOD) and sagittal oblique (SOD) diameters and sagittal oblique length (SOL) were 6.3-19, 3.4-20 and 5-21 mm, respectively. All appendages (>or=10 mm) demonstrated significant contraction during atrial systole (greatest diameter reduction was AOD [3.8 mm, 27%]). Significant correlations were noted between AOD-contraction and AOD (R = 0.57, P < 0.05) and SOD-contraction and AOD, SOD and SOL (R = 0.6, P < 0.05). Mean diverticulum volume in atrial diastole was 468.4 +\\/- 493 mm(3) and in systole was 171.2 +\\/- 122 mm(3), indicating a mean change in volume of 297.2 +\\/- 390 mm(3), P < 0.0001. Stepwise multiple regression analysis revealed SOL to be the strongest independent predictor of appendage contractility (R(2) = 0.86, P < 0.0001) followed by SOD (R(2) = 0.91, P < 0.0001). Accessory LAAs show significant contractile properties on cardiac CT. Those accessory LAAs with a large sagittal height or depth should be evaluated for contractile properties, and if present should be examined for ectopic activity during electrophysiological studies.

  13. Neonatal repair of left atrial diverticulum with gigantic thrombus without cardiopulmonary bypass.

    Science.gov (United States)

    Higashida, Akihiko; Hoashi, Takaya; Sakaguchi, Heima; Ichikawa, Hajime

    2017-04-08

    A 5-day-old neonate with coarctation of the aorta, hypoplastic aortic arch, large apical muscular ventricular septal defect, and patent ductus arteriosus developed pulmonary over-circulation and systemic hypoperfusion underwent bilateral pulmonary artery banding through median sternotomy as a part of hybrid stage I palliation. At operation, left atrial diverticulum with gigantic thrombus formation at the base of the left atrial appendage was incidentally detected by intraoperative direct echocardiography, and therefore, was successfully resected with the whole thrombus inside it without use of cardiopulmonary bypass. Histopathological finding was compatible with diverticulum. The patient was free from atrial arrhythmia and recurrent thrombus formation.

  14. [Successful treatment of atrial fibrillation by resection of a congenital aneurysm of the left heart atrium].

    Science.gov (United States)

    Heigl, F; Steinbeck, G; Rienmüller, R; Kemkes, B M; Klinner, W

    1992-10-01

    Atrial fibrillation occurred in a 27-year-old patient with a history of globular cardiac enlargement since childhood. Because of the probable causal relationship between the preexisting heart disease-which was supposed to be an enlargement of the left atrium-and the rhythm disturbance, we recommended a surgical intervention. Cardiac surgery revealed a congenital aneurysm of the left atrial appendage which could be resected without any complication. Postoperatively, atrial fibrillation had returned to regular sinus rhythm. The bad prognosis with a high risk of systemic embolism is the reason why early cardiac surgery should be performed after diagnosis of this rare anomaly (20 reported cases) of the left atrium.

  15. Atrial fibrillation

    DEFF Research Database (Denmark)

    Lip, Gregory Y H; Fauchier, Laurent; Freedman, Saul B;

    2016-01-01

    Atrial fibrillation (AF) is the most common sustained cardiac rhythm disorder, and increases in prevalence with increasing age and the number of cardiovascular comorbidities. AF is characterized by a rapid and irregular heartbeat that can be asymptomatic or lead to symptoms such as palpitations...

  16. Atrial fibrillation

    DEFF Research Database (Denmark)

    Olesen, Morten S; Nielsen, Morten W; Haunsø, Stig;

    2014-01-01

    Atrial fibrillation (AF) is the most common cardiac arrhythmia affecting 1-2% of the general population. A number of studies have demonstrated that AF, and in particular lone AF, has a substantial genetic component. Monogenic mutations in lone and familial AF, although rare, have been recognized...

  17. Low Energy Multi-Stage Atrial Defibrillation Therapy Terminates Atrial Fibrillation with Less Energy than a Single Shock

    Science.gov (United States)

    Li, Wenwen; Janardhan, Ajit H.; Fedorov, Vadim V.; Sha, Qun; Schuessler, Richard B.; Efimov, Igor R.

    2011-01-01

    Background Implantable device therapy of atrial fibrillation (AF) is limited by pain from high-energy shocks. We developed a low-energy multi-stage defibrillation therapy and tested it in a canine model of AF. Methods and Results AF was induced by burst pacing during vagus nerve stimulation. Our novel defibrillation therapy consisted of three stages: ST1 (1-4 low energy biphasic shocks), ST2 (6-10 ultra-low energy monophasic shocks), and ST3 (anti-tachycardia pacing). Firstly, ST1 testing compared single or multiple monophasic (MP) and biphasic (BP) shocks. Secondly, several multi-stage therapies were tested: ST1 versus ST1+ST3 versus ST1+ST2+ST3. Thirdly, three shock vectors were compared: superior vena cava to distal coronary sinus (SVC>CSd), proximal coronary sinus to left atrial appendage (CSp>LAA) and right atrial appendage to left atrial appendage (RAA>LAA). The atrial defibrillation threshold (DFT) of 1BP shock was less than 1MP shock (0.55 ± 0.1 versus 1.38 ± 0.31 J; p =0.003). 2-3 BP shocks terminated AF with lower peak voltage than 1BP or 1MP shock and with lower atrial DFT than 4 BP shocks. Compared to ST1 therapy alone, ST1+ST3 lowered the atrial DFT moderately (0.51 ± 0.46 versus 0.95 ± 0.32 J; p = 0.036) while a three-stage therapy, ST1+ST2+ST3, dramatically lowered the atrial DFT (0.19 ± 0.12 J versus 0.95 ± 0.32 J for ST1 alone, p=0.0012). Finally, the three-stage therapy ST1+ST2+ST3 was equally effective for all studied vectors. Conclusions Three-stage electrotherapy significantly reduces the AF defibrillation threshold and opens the door to low energy atrial defibrillation at or below the pain threshold. PMID:21980076

  18. Receptors for atrial natriuretic peptide (ANP) and regulation of thyroglobulin secretion by ANP in human thyroid cells

    Energy Technology Data Exchange (ETDEWEB)

    Sellitti, D.F.; Tseng, Y.C.L.; Wartofsky, L. (Uniformed Services Univ. of the Health Sciences, Bethesda, MD (USA) Walter Reed Army Medical Center, Washington, DC (USA))

    1989-01-01

    Specific binding sites for atrial natriuretic peptide (ANP) were identified and characterized in primary cultures of human thyroid cells. Saturation analysis using ({sup 125}I) {alpha} rat (1-28) ANP as the ligand showed a single class of high affinity binding which was inhibited by atriopeptin I and the {alpha} -human form of ANP, but not by a C-terminal fragment (13-28) of the peptide. The number of ANP binding sites in these cultures was not altered by the thyroid hormone concentration of the medium. In a dose-response experiment, thyroglobulin secretion was significantly reduced in the presence of 0.01 nM ANP and was maximally reduced with 10 nM ANP. Cyclic GMP production was increased threefold in the presence of 100 nM ANP, but was unchanged with lower doses of the peptides. The finding of receptors in thyroid follicular cells suggests a hitherto unrecognized role of ANP in the thyroid gland.

  19. Gene Expression of Atrial Calcium-Handling Proteins in Patients with Rheumatic Heart Disease and Atrial Fibrillation

    Institute of Scientific and Technical Information of China (English)

    伍伟锋; 黄从新; 刘唐威; 朱树雄

    2003-01-01

    Objectives To investigate the gene expression of calcium-handling proteins inpatients with rheumatic heart disease (RHD) and atrialfibrillation (AF) . Methods A total of 50 patientswith rheumatic mitral valve disease were included.According to cardiac rhythm and duration of episode ofAF, patients were divided into four groups: sinusrhythm group, paroxysmal AF group, persistent AF forless than 6 months group and persistent AF for morethan 6 months group. Atrial tissue was obtained fromthe right atrial appendage, the right atrial free wall andthe left atrial appendage respectively during open heartsurgery. Total RNA was isolated and reversly tran-scribed into cDNA. In a semi -quantitative polymerasechain reaction the cDNA of interest and of glyceralde-hyde3 -phosphate dehydrogenase (GAPDH) were am-plified and separated by ethidium bromide - stained gelelectrophoresis. Multiple liner regress was used forcorrelation between the mRNA amount and age, sex,right atrial diameter (RAd) and left atrial diameter(LAd) Results The mRNA of L- type calciumchannelα1c subunit, of Ca2 + - ATPase and of ryanodinereceptor in patients with persistent AF for more than 6months were significantly decreased ( P all < 0. 01 ). But no alterations of the mRNA levels for SR phos-pholamban and calsequestrin were observed in patientswith persistent AF for more than 6 months comparedwith patients with sinus rhythm, paroxysmal AF andpersistent AF for less than 6 months( P all > 0.05) .There was no difference of the gene expression amongthe three atrial tissue sampling sites(P all > 0.05). Age, gender, RAd and LAd had no significant effectson the gene expression of calcium- handling proteins( P all> 0. 05). Conclusions The mRNA expressionof calcium -handling proteins is down -regulated onlyin patients with RHD and long- term persistent AF.Such abnormalities may be related to the initiationand/or perpetuation of AF in the patients with RHD.

  20. Content of alpha-linolenic acid in human atrial tissue correlates with plasma levels of alpha-linolenic acid

    DEFF Research Database (Denmark)

    Gu, Jiwei; Eschen, Rikke Bülow; Andreasen, Annette

    and ALA levels were compared by the Pearson correlation coefficient. Results: There was a statistical significant correlation (r=0.54, 95% confidence interval: 0.30-0.71) between levels of ALA in plasma phospholipids and atrial tissue. Conclusion: The content of ALA in plasma phospholipids is a short term...... indicator of intake of ALA and this correlated well with the content of ALA in atrial tissue. Atrial tissue is not readily available but this study shows that determination of plasma phospholipids may be useful to further investigate an antiarrhythmic effect of ALA on AF....

  1. Study on the incidence of testicular and epididymal appendages in patients with cryptorchidism

    Directory of Open Access Journals (Sweden)

    Favorito Luciano A.

    2004-01-01

    Full Text Available OBJECTIVE: To study the incidence of testicular and epididymal appendages in patients with cryptorchidism. MATERIALS AND METHODS: We studied 65 patients with cryptorchidism, totalizing 83 testes and 40 patients who had prostate adenocarcinoma and hydrocele (control group, totalizing 55 testes. The following situations were analyzed: I absence of testicular and epididymal appendages, II presence of testicular appendage only, III presence of epididymal appendage, IV presence of testicular and epididymal appendage, V presence of 2 epididymal appendages and 1 testicular appendage and VI presence of paradidymis or vas aberrans of Haller. RESULTS: In patients with cryptorchidism we found testicular appendages in 23 cases (41.8%, epididymal appendages in 9 (16.3%, testicular and epididymal appendage in 8 (14.5%, 2 epididymal appendages and 1 testicular in 1 (1.8% and absence of appendages in 14 (25.4%. In the control group, we found testicular appendages in 29 (34.9%, epididymal appendages in 19 (22.8%, testicular and epididymal appendage in 7 (8.4%, and absence of appendages in 28 (33.7%, we did not find 2 epididymal appendages in this group, and none of the patients in the 2 groups presented paradidymis or vas aberrans of Haller. CONCLUSION: The occurrence of testicular and epididymal appendages is quite variable. There was no statistically significant difference in the incidence and distribution of the testicular and epididymal appendages between patients with cryptorchidism and those from the control group.

  2. Prostacyclins have no direct inotropic effect on isolated atrial strips from the normal and pressure-overloaded human right heart.

    Science.gov (United States)

    Holmboe, Sarah; Andersen, Asger; Jensen, Rebekka V; Kimose, Hans Henrik; Ilkjær, Lars B; Shen, Lei; Clapp, Lucie H; Nielsen-Kudsk, Jens Erik

    2017-01-01

    Prostacyclins are vasodilatory agents used in the treatment of pulmonary arterial hypertension. The direct effects of prostacyclins on right heart function are still not clarified. The aim of this study was to investigate the possible direct inotropic properties of clinical available prostacyclin mimetics in the normal and the pressure-overloaded human right atrium. Trabeculae from the right atrium were collected during surgery from chronic thromboembolic pulmonary hypertension (CTEPH) patients with pressure-overloaded right hearts, undergoing pulmonary thromboendarterectomy (n = 10) and from patients with normal right hearts operated by valve replacement or coronary bypass surgery (n = 9). The trabeculae were placed in an organ bath, continuously paced at 1 Hz. They were subjected to increasing concentrations of iloprost, treprostinil, epoprostenol, or MRE-269, followed by isoprenaline to elicit a reference inotropic response. The force of contraction was measured continuously. The expression of prostanoid receptors was explored through quantitative polymerase chain reaction (qPCR). Iloprost, treprostinil, epoprostenol, or MRE-269 did not alter force of contraction in any of the trabeculae. Isoprenaline showed a direct inotropic response in both trabeculae from the pressure-overloaded right atrium and from the normal right atrium. Control experiments on ventricular trabeculae from the pig failed to show an inotropic response to the prostacyclin mimetics. qPCR demonstrated varying expression of the different prostanoid receptors in the human atrium. In conclusion, prostacyclin mimetics did not increase the force of contraction of human atrial trabeculae from the normal or the pressure-overloaded right heart. These data suggest that prostacyclin mimetics have no direct inotropic effects in the human right atrium.

  3. Fibroblast growth factor-21 is positively associated with atrial fibrosis in atrial fibrillation patients with rheumatic heart disease.

    Science.gov (United States)

    Wang, Rui; Yi, Xin; Li, Xiaoyan; Jiang, Xuejun

    2015-01-01

    Fibroblast growth factor-21 (FGF-21) has been discovered as a strong hormone, plays an important role in lipid metabolism, glucose metabolism, associated with several diseases such as obesity, metabolic syndrome, diabetes mellitus, and cardiovascular events; however, no evidence is available concerning the relationship of FGF-21 and atrial fibrosis in patients with atrial fibrillation (AF) and rheumatic heart disease (RHD). Twenty-four rheumatic heart disease patients were divided into two groups, 12 cases with AF and 12 cases with sinus rhythm (SR). Clinical characteristics and blood samples were collected before surgery; right atrial appendage samples were taken in the surgery of valve replacement. HE staining was performed to determine cross-sectional area of atrial myocytes; Masson stained sections and mRNA levels of cardiac fibrosis biomarkers were used to evaluate the degree of cardiac fibrosis; the level of FGF-21 was evaluated via enzyme-linked immunosorbent assay (ELISA), immunohistochemistry, and real-time polymerase chain reaction (PCR). Compared with SR group, cross-sectional area of atrial myocytes and collagen volume fraction were significantly increased in the atrial tissue of AF group. The distribution of FGF-21 in the AF group was remarkably higher than SR group. In addition, plasma and mRNA levels of FGF-21 in atrial tissue of AF showed the same trend as the result of immunohistochemistry. Using linear correlation analysis, the expression level of FGF-21 was found to be positively related to the degree of atrial fibrosis. FGF-21 might involve in the development and maintenance of atrial fibrosis in atrial fibrillation with rheumatic heart disease, and FGF-21 could be used as a novel biomarker to evaluate myocardial fibrosis in the future.

  4. Efficacy of adjunctive measures used to assist pulmonary vein isolation for atrial fibrillation: a systematic review.

    Science.gov (United States)

    Nair, Girish M; Raut, Roshan; Bami, Karan; Nery, Pablo B; Redpath, Calum J; Sadek, Mouhannad M; Green, Martin S; Birnie, David H

    2017-01-01

    Pulmonary vein reconnection leading to recurrence of atrial arrhythmias after pulmonary vein isolation (PVI) for atrial fibrillation remains a significant challenge. A number of adjunctive measures during PVI have been used to attempt to reduce pulmonary vein reconnection and recurrence of atrial arrhythmias. We performed a systematic review of the literature and meta-analysis of studies evaluating the efficacy of adjunctive measures used during PVI in reducing recurrent atrial arrhythmias. Our literature search found four interventions that met the prespecified definition of adjunctive measure: adenosine testing post-PVI, contact force-guided PVI, pacing inexcitability of the ablation line during PVI and additional ablation based on the computed tomography thickness of the pulmonary vein-left atrial appendage ridge. Sixteen studies enrolling 3507 patients met all inclusion and exclusion criteria. PVI performed with adjunctive measures was shown to reduce the 1-year recurrence rate of atrial arrhythmias. The point estimate for the combined relative risk of atrial arrhythmia recurrence was 0.56 [95% confidence interval (CI): 0.43-0.73; P value PVI with adjunctive measures group. PVI for atrial fibrillation assisted by adjunctive measures results in clinically significant reduction of recurrent atrial arrhythmias. Additional research is required to assess the relative efficacy of individual or combined adjunctive strategies used during PVI for atrial fibrillation.

  5. I(f) blocking potency of ivabradine is preserved under elevated endotoxin levels in human atrial myocytes.

    Science.gov (United States)

    Scheruebel, Susanne; Koyani, Chintan N; Hallström, Seth; Lang, Petra; Platzer, Dieter; Mächler, Heinrich; Lohner, Karl; Malle, Ernst; Zorn-Pauly, Klaus; Pelzmann, Brigitte

    2014-07-01

    Lower heart rate is associated with better survival in patients with multiple organ dysfunction syndrome (MODS), a disease mostly caused by sepsis. The benefits of heart rate reduction by ivabradine during MODS are currently being investigated in the MODIfY clinical trial. Ivabradine is a selective inhibitor of the pacemaker current If and since If is impaired by lipopolysaccharide (LPS, endotoxin), a trigger of sepsis, we aimed to explore If blocking potency of ivabradine under elevated endotoxin levels in human atrial cardiomyocytes. Treatment of myocytes with S-LPS (containing the lipid A moiety, a core oligosaccharide and an O-polysaccharide chain) but not R595 (an O-chain lacking LPS-form) caused If inhibition under acute and chronic septic conditions. The specific interaction of S-LPS but not R595 to pacemaker channels HCN2 and HCN4 proves the necessity of O-chain for S-LPS-HCN interaction. The efficacy of ivabradine to block If was reduced under septic conditions, an observation that correlated with lower intracellular ivabradine concentrations in S-LPS- but not R595-treated cardiomyocytes. Computational analysis using a sinoatrial pacemaker cell model revealed that despite a reduction of If under septic conditions, ivabradine further decelerated pacemaking activity. This novel finding, i.e. If inhibition by ivabradine under elevated endotoxin levels in vitro, may provide a molecular understanding for the efficacy of this drug on heart rate reduction under septic conditions in vivo, e.g. the MODIfY clinical trial.

  6. Atrial Fibrillation.

    Science.gov (United States)

    Zimetbaum, Peter

    2017-03-07

    This issue provides a clinical overview of atrial fibrillation, focusing on diagnosis, treatment, and practice improvement. The content of In the Clinic is drawn from the clinical information and education resources of the American College of Physicians (ACP), including MKSAP (Medical Knowledge and Self-Assessment Program). Annals of Internal Medicine editors develop In the Clinic in collaboration with the ACP's Medical Education and Publishing divisions and with the assistance of additional science writers and physician writers.

  7. Mosaic trisomy 13 and a sacral appendage.

    Science.gov (United States)

    Pachajoa, Harry; Meza Escobar, Luis Enrique

    2013-07-31

    Mosaic trisomy 13 occurs when there is a percentage of trisomic cells for an entire chromosome 13, while the remaining percentage of cells is euploid. The prevalence of this syndrome ranges from 1 in 10 000 to 1 in 20 000 births. Complete, partial or mosaic forms of this disorder can occur. The phenotype of mosaic trisomy 13 patients varies widely. Patients with mosaic trisomy 13 usually have a longer survival and a less severe phenotype compared to patients with complete trisomy 13. Genetic counselling is difficult due to the wide variation among the clinical manifestations of these patients. There have been 49 cases of mosaic trisomy 13 reported in the literature. We report the case of a patient with mosaic trisomy 13, a sacral appendage and a cleft lip and palate.

  8. Partial co-option of the appendage patterning pathway in the development of abdominal appendages in the sepsid fly Themira biloba.

    Science.gov (United States)

    Bowsher, Julia H; Nijhout, H Frederik

    2009-12-01

    The abdominal appendages on male Themira biloba (Diptera: Sepsidae) are complex novel structures used during mating. These abdominal appendages superficially resemble the serially homologous insect appendages in that they have a joint and a short segment that can be rotated. Non-genital appendages do not occur in adult pterygote insects, so these abdominal appendages are novel structures with no obvious ancestry. We investigated whether the genes that pattern the serially homologous insect appendages have been co-opted to pattern these novel abdominal appendages. Immunohistochemistry was used to determine the expression patterns of the genes extradenticle (exd), Distal-less (Dll), engrailed (en), Notch, and the Bithorax Complex in the appendages of T. biloba during pupation. The expression patterns of Exd, En, and Notch were consistent with the hypothesis that a portion of the patterning pathway that establishes the coxopodite has been co-opted to pattern the developing abdominal appendages. However, Dll was only expressed in the bristles of the developing appendages and not the proximal-distal axis of the appendage itself. The lack of Dll expression indicates the absence of a distal domain of the appendage suggesting that sepsid abdominal appendages only use genes that normally pattern the base of segmental appendages.

  9. Preparation of mono-radioiodinated tracers for study of the in vivo metabolism of atrial natriuretic peptide in humans

    Energy Technology Data Exchange (ETDEWEB)

    Clerico, A. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Iervasi, G. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Manfredi, C. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Salvadori, S. [Dept. of Pharmaceutical Sciences, Univ. of Ferrara (Italy); Marastoni, M. [Dept. of Pharmaceutical Sciences, Univ. of Ferrara (Italy); Del Chicca, M.G. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Giannessi, D. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Del Ry, S. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Andreassi, M.G. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Sabatino, L. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Iascone, M.R. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Biagini, A. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Donato, L. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica

    1995-09-01

    The authors evaluate the optimum chemical conditions for labelling atrial natriuretic peptide (ANP) and its metabolites and for preparing highly purified radiotracers which can be used for in vivo kinetic studies of ANP in humans. Synthetic {alpha} h{sub 1-28}ANP and some hormone metabolites were iodinated with Na{sup 125}I or Na{sup 131}I by means of the lactoperoxidase (ANP) or the chloramine-T (ANP metabolites) technique. The biological activity of labelled ANP was tested by means of a binding study using mouse cardiac membranes. A high-performance liquid chromatography (HPLC) procedure was used to purify the labelled hormone and the principal labelled metabolites in venous plasma samples collected up to 50 min after the injection of {sup 125}I-labelled ANP from nine healthy men. The main ANP kinetic parameters were derived from the disappearance curves of the [{sup 125}I]ANP, which were satisfactorily fitted by a bi-exponential function in all subjects. The main advantages of this tracer technique are high accuracy, allowing the identification of the metabolites produced in vivo under steady-state conditions after injection of the precursor (labelled hormone) high sensitivity, allowing the detection of minimal quantities of metabolites high specificity, allowing the detection of possible in vitro artefactual generation of cleavage products of ANP using an internal labelled standard. Utilizing this tracer method, it was possible to estimate the principal parameters of ANP kinetics and also to plot the appearance curves of the labelled metabolites produced in vivo after the injection of the labelled precursor. (orig.). With 5 figs.

  10. Expression of Extracellular Signal-regulated Kinase and Angiotensin-converting Enzyme in Human Atria during Atrial Fibrillation

    Institute of Scientific and Technical Information of China (English)

    戴友平; 王祥; 曹林生; 杨杪; 邬堂春

    2004-01-01

    Summary: In order to investigate the changes in the expression of extracellular signal-regulated kinase (ERK1/ERK2) and angiotensin-converting enzyme (ACE) in the patients with atrial fibrillation (AF), 52 patients with rheumatic heart diseases were examined. Nineteen patients had chronic persistent AF (AF≥6 months, CAF), 12 patients had paroxymal AF (PAF) and 21 patients had no history of AF. The ERK expression was detected at the mRNA level by reverse transcription polymerase chain reaction, at the protein level by Western blotting and at atrial tissue level by immunohistochemistry. ERK-activating kinases (MEK1/2) and ACE were determined by Western blotting techniques. The expression of ERK2-mRNA was increased in the patients with CAF (74±19 U vs sinus rhythm: 32±24 U, P<0.05). Activated ERK1/ERK2 and MEK1/2 were increased to more than 150 % in the patients with AF compared to those with sinus rhythm. No significant difference between CAF and PAF was found. The expression of ACE was three-fold increased in the patients with CAF compared to those with sinus rhythm. Patients with AF showed an increased expression of ERK1/ERK2 in atrial interstitial cells and marked atrial fibrosis. An ACE-dependent increase in the amounts of activated ERK1/ERK2 in atrial interstitial cells may be one of molecular mechanisms for the development of atrial fibrosis in the patients with AF. These findings may have important impact on the treatment of AF.

  11. A Rare Cause of Abdominal Pain: Primary Epiploic Appendagitis (PEA

    Directory of Open Access Journals (Sweden)

    Gulbanu Erkan

    2016-07-01

    Full Text Available Primary epiploic appendagitis (PEA is a rare disease caused by torsion or spontaneous thrombosis of the central vein that drains epiploic appendages (EA. Primary Epiploic Appendagitis (PEA is an ischemic infarction. Although PEA is a self-limiting disease and does not require surgical intervention in most cases, it may mimic diseases that require surgical intervention or aggressive medical therapy, such as appendicitis, diverticulitis, or cholecystitis. In order to avoid unnecessary surgical intervention, PEA should be kept in mind when patients present with acute abdominal pain. In this report, we present a PEA case admitted with abdominal pain.

  12. Distribution and function of sodium channel subtypes in human atrial myocardium

    NARCIS (Netherlands)

    Kaufmann, Susann G.; Westenbroek, Ruth E.; Maass, Alexander H.; Lange, Volkmar; Renner, Andre; Wischmeyer, Erhard; Bonz, Andreas; Muck, Jenny; Ertl, Georg; Catterall, William A.; Scheuer, Todd; Maier, Sebastian K. G.

    2013-01-01

    Voltage-gated sodium channels composed of a pore-forming alpha subunit and auxiliary beta subunits are responsible for the upstroke of the action potential in cardiac muscle. However, their localization and expression patterns in human myocardium have not yet been clearly defined. We used immunohist

  13. Isolation of cardiac myosin light-chain isotypes by chromatofocusing. Comparison of human cardiac atrial light-chain 1 and foetal ventricular light-chain 1.

    Science.gov (United States)

    Vincent, N D; Cummins, P

    1985-04-01

    Cardiac myosin light chain isotypes have been resolved using chromatofocusing, a new preparative column chromatographic technique. The method relies on production of narrow-range, shallow and stable pH gradients using ion-exchange resins and buffers with even buffering capacity over the required pH range. Light chains were resolved in order of decreasing isoelectric point in the pH range 5.2-4.5. Gradients of delta pH = 0.004-0.006/ml elution volume were achieved which were capable of resolving light chains with isoelectric point differences of only 0.03. Analytical isoelectric focusing of light chains in polyacrylamide gels could be used to predict the results of preparative chromatofocusing for method development. Chromatofocusing was capable of resolving human and bovine cardiac light chain 1 and 2 subunits, atrial (ALC) and ventricular (VLC) light chain isotypes and homologous VLC-2 and VLC-2* light chains. The technique was used to purify and resolve the human foetal ventricular light chain 1 (FLC-1) from adult ventricular light chain 1 (VLC-1) present in foetal ventricles and the atrial light chain 1 (ALC-1) in adult atria. Comparative peptide mapping studies and amino acid analyses were carried out on FLC-1 and ALC-1. No differences were detected between FLC-1 and ALC-1 using three different proteases and amino acid compositions were similar with the exception of glycine content. The studies indicate that FLC-1 and ALC-1 are homologous, and possibly identical, light chains. Comparison of human FLC-1/ALC-1 with VLC-1 suggested marked structural and chemical differences in these light chain isotypes, in particular in the contents of methionine, proline, lysine and alanine residues. Differences in the contents of these residues were also apparent in the corresponding bovine atrial and ventricular light chains [Wikman-Coffelt, J. & Srivastava, S. (1979) FEBS Lett. 106, 207-212]. The latter three residues are known to be rich in the N-termini of cardiac and

  14. The comparative hydrodynamics of rapid rotation by predatory appendages.

    Science.gov (United States)

    McHenry, M J; Anderson, P S L; Van Wassenbergh, S; Matthews, D G; Summers, A P; Patek, S N

    2016-11-01

    Countless aquatic animals rotate appendages through the water, yet fluid forces are typically modeled with translational motion. To elucidate the hydrodynamics of rotation, we analyzed the raptorial appendages of mantis shrimp (Stomatopoda) using a combination of flume experiments, mathematical modeling and phylogenetic comparative analyses. We found that computationally efficient blade-element models offered an accurate first-order approximation of drag, when compared with a more elaborate computational fluid-dynamic model. Taking advantage of this efficiency, we compared the hydrodynamics of the raptorial appendage in different species, including a newly measured spearing species, Coronis scolopendra The ultrafast appendages of a smasher species (Odontodactylus scyllarus) were an order of magnitude smaller, yet experienced values of drag-induced torque similar to those of a spearing species (Lysiosquillina maculata). The dactyl, a stabbing segment that can be opened at the distal end of the appendage, generated substantial additional drag in the smasher, but not in the spearer, which uses the segment to capture evasive prey. Phylogenetic comparative analyses revealed that larger mantis shrimp species strike more slowly, regardless of whether they smash or spear their prey. In summary, drag was minimally affected by shape, whereas size, speed and dactyl orientation dominated and differentiated the hydrodynamic forces across species and sizes. This study demonstrates the utility of simple mathematical modeling for comparative analyses and illustrates the multi-faceted consequences of drag during the evolutionary diversification of rotating appendages. © 2016. Published by The Company of Biologists Ltd.

  15. Angiotensin II activates signal transducers and activators of transcription 3 via Rac1 in the atrial tissue in permanent atrial fibrillation patients with rheumatic heart disease.

    Science.gov (United States)

    Xue, Xiao-Dong; Huang, Jian-Hua; Wang, Hui-Shan

    2015-01-01

    Patients with rheumatic heart disease (RHD) often experience persistent atrial fibrillation (AF) associated with adverse atrial structural remodeling (ASR) manifested by atrial fibrosis and left atrial enlargement. The aim of this study was to explore the potential molecular signaling mechanisms for atrial fibrosis and ASR. Twenty RHD patients with persistent AF and 10 RHD patients with sinus rhythm (Group A) were recruited in our study, which all underwent transthoracic echocardiography. Right atrial appendage (RAA) tissue samples were obtained from these patients during mitral/aortic valve replacement operation. The AF patients were further divided into two groups according to left atrial diameter (LAD): Group B with LAD ranging 50-65 mm and Group C with LAD >65 mm. Histological examinations were performed with hematoxylin-eosin staining and Masson's trichrome staining. Atrial angiotensin II (AngII) content was measured by ELISA. Rac1 and STAT3 protein levels were determined by Western blot analysis. Hematoxylin-eosin staining demonstrated highly organized arrangement of atrial muscles in control Group A and significant derangement in both Group B and C AF patients with reduced cell density and increased cell size. Moreover, Masson's trichrome staining showed that atrial myocytes were surrounded by large trunks of collagen fibers in both Group B and C, but not in Group A. There was a positive correlation between atrial tissue fibrosis and LAD. AngII content was markedly higher in Group C than in Group B than in Group A, which was positively correlated with LAD. Similarly, Rac1 and STAT3 protein levels were found considerably higher in Group C and B than in Group A with excellent correlation to LAD. Our study unraveled for the first time the AngII/Rac1/STAT3 signaling as a mechanism for ASR thereby AF in a particular clinical setting-RHD patients with persistent AF and indicated inhibition of this pathway may help ameliorating adverse ASR.

  16. Impaired relaxation despite upregulated calcium-handling protein atrial myocardium from type 2 diabetic patients with preserved ejection fraction.

    Science.gov (United States)

    Lamberts, Regis R; Lingam, Shivanjali J; Wang, Heng-Yu; Bollen, Ilse A E; Hughes, Gillian; Galvin, Ivor F; Bunton, Richard W; Bahn, Andrew; Katare, Rajesh; Baldi, J Chris; Williams, Michael J A; Saxena, Pankaj; Coffey, Sean; Jones, Peter P

    2014-04-05

    Diastolic dysfunction is a key factor in the development and pathology of cardiac dysfunction in diabetes, however the exact underlying mechanism remains unknown, especially in humans. We aimed to measure contraction, relaxation, expression of calcium-handling proteins and fibrosis in myocardium of diabetic patients with preserved systolic function. Right atrial appendages from patients with type 2 diabetes mellitus (DM, n = 20) and non-diabetic patients (non-DM, n = 36), all with preserved ejection fraction and undergoing coronary artery bypass grafting (CABG), were collected. From appendages, small cardiac muscles, trabeculae, were isolated to measure basal and β-adrenergic stimulated myocardial function. Expression levels of calcium-handling proteins, sarcoplasmic reticulum Ca2+ ATPase (SERCA2a) and phospholamban (PLB), and of β1-adrenoreceptors were determined in tissue samples by Western blot. Collagen deposition was determined by picro-sirius red staining. In trabeculae from diabetic samples, contractile function was preserved, but relaxation was prolonged (Tau: 74 ± 13 ms vs. 93 ± 16 ms, non-DM vs. DM, p = 0.03). The expression of SERCA2a was increased in diabetic myocardial tissue (0.75 ± 0.09 vs. 1.23 ± 0.15, non-DM vs. DM, p = 0.007), whereas its endogenous inhibitor PLB was reduced (2.21 ± 0.45 vs. 0.42 ± 0.11, non-DM vs. DM, p = 0.01). Collagen deposition was increased in diabetic samples. Moreover, trabeculae from diabetic patients were unresponsive to β-adrenergic stimulation, despite no change in β1-adrenoreceptor expression levels. Human type 2 diabetic atrial myocardium showed increased fibrosis without systolic dysfunction but with impaired relaxation, especially during β-adrenergic challenge. Interestingly, changes in calcium-handling protein expression suggests accelerated active calcium re-uptake, thus improved relaxation, indicating a compensatory calcium-handling mechanism in diabetes

  17. Managing atrial fibrillation in the very elderly patient: challenges and solutions.

    Science.gov (United States)

    Karamichalakis, Nikolaos; Letsas, Konstantinos P; Vlachos, Konstantinos; Georgopoulos, Stamatis; Bakalakos, Athanasios; Efremidis, Michael; Sideris, Antonios

    2015-01-01

    Atrial fibrillation (AF) is the most common arrhythmia affecting elderly patients. Management and treatment of AF in this rapidly growing population of older patients involve a comprehensive assessment that includes comorbidities, functional, and social status. The cornerstone in therapy of AF is thromboembolic protection. Anticoagulation therapy has evolved, using conventional or newer medications. Percutaneous left atrial appendage closure is a new invasive procedure evolving as an alternative to systematic anticoagulation therapy. Rate or rhythm control leads to relief in symptoms, fewer hospitalizations, and an improvement in quality of life. Invasive methods, such as catheter ablation, are the new frontier of treatment in maintaining an even sinus rhythm in this particular population.

  18. Relationship between local production of microRNA-328 and atrial substrate remodeling in atrial fibrillation.

    Science.gov (United States)

    Soeki, Takeshi; Matsuura, Tomomi; Bando, Sachiko; Tobiume, Takeshi; Uematsu, Etsuko; Ise, Takayuki; Kusunose, Kenya; Yamaguchi, Koji; Yagi, Shusuke; Fukuda, Daiju; Yamada, Hirotsugu; Wakatsuki, Tetsuzo; Shimabukuro, Michio; Sata, Masataka

    2016-12-01

    The underlying mechanism of atrial substrate remodeling in atrial fibrillation (AF) remains unknown. In this study, we investigated whether local and systemic levels of microRNA (miR) might be associated with the presence of AF and with left atrial (LA) substrate properties. Blood from the periphery, pulmonary vein (PV), and left atrial appendage (LAA) was sampled from 30 patients with AF undergoing PV isolation, and from 10 control subjects with Wolff-Parkinson-White syndrome and without AF. We measured peripheral, PV, and LAA plasma levels of miR-1, -26, -133a, -328, and -590 by reverse transcription-polymerase chain reaction. LA global contact mapping during sinus rhythm was performed before PV isolation. Plasma levels of miR-328 were higher in patients with AF than in control subjects. Plasma miR-328 levels were significantly higher in the LAA than in the periphery and PV in patients with AF, but not in control subjects. Plasma miR-1 levels were also higher in the LAA than in the PV in AF patients. Interestingly, LAA plasma levels of miR-328 showed a positive correlation with the LA voltage zone index (area with voltage <0.5mV divided by total LA surface area) and a weak correlation with LA volume. Local production of miR-328 in the left atrium may be involved in the process of atrial remodeling in patients with AF. Copyright © 2016 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

  19. Varying types of circus movement re-entry with both normal and dissociated contralateral conduction causing different right and left atrial rhythms in canine atrial flutter.

    Science.gov (United States)

    Yamauchi, S; Boineau, J P; Schuessler, R B; Cox, J L

    1998-03-01

    The purpose of this study was to develop an animal model of atrial flutter (AFL) or fibrillation (AFB) and to determine precisely the pathway of atrial activation during arrhythmias induced by programmed stimulation. In 10 dogs, a shunt from the left subclavian artery to the left upper pulmonary vein was created to produce left atrial enlargement. Five months later, using programmed electrical stimulation, it was possible to induce 17 sustained atrial tachycardias in 9 of the 10 dogs, including 9 episodes of AFL caused by circus movement re-entry, 6 episodes of focal tachycardia, and 2 episodes of AFB. Short cycle length left atrial tachycardias caused by either circus movement or a focus did not propagate in a uniform 1:1 pattern to the right atrium (RA), resulting in RA dissociation. In these arrhythmias, complex wavefronts from both current and preceding left atrial cycles coexisted in the RA. Circus movement was associated with a spectrum of different re-entrant pathways with different path lengths. These differences in the path length were determined by various ways in which obstacles such as the superior vena cava and orifice of the right atrial appendage or pulmonary vein orifices were combined by contiguous areas of functional block.

  20. Selection of reference genes is critical for miRNA expression analysis in human cardiac tissue. A focus on atrial fibrillation

    Science.gov (United States)

    Masè, Michela; Grasso, Margherita; Avogaro, Laura; D’Amato, Elvira; Tessarolo, Francesco; Graffigna, Angelo; Denti, Michela Alessandra; Ravelli, Flavia

    2017-01-01

    MicroRNAs (miRNAs) are emerging as key regulators of complex biological processes in several cardiovascular diseases, including atrial fibrillation (AF). Reverse transcription-quantitative polymerase chain reaction is a powerful technique to quantitatively assess miRNA expression profile, but reliable results depend on proper data normalization by suitable reference genes. Despite the increasing number of studies assessing miRNAs in cardiac disease, no consensus on the best reference genes has been reached. This work aims to assess reference genes stability in human cardiac tissue with a focus on AF investigation. We evaluated the stability of five reference genes (U6, SNORD48, SNORD44, miR-16, and 5S) in atrial tissue samples from eighteen cardiac-surgery patients in sinus rhythm and AF. Stability was quantified by combining BestKeeper, delta-Cq, GeNorm, and NormFinder statistical tools. All methods assessed SNORD48 as the best and U6 as the worst reference gene. Applications of different normalization strategies significantly impacted miRNA expression profiles in the study population. Our results point out the necessity of a consensus on data normalization in AF studies to avoid the emergence of divergent biological conclusions. PMID:28117343

  1. Altered expression of micro-RNA 199a and increased levels of cardiac SIRT1 protein are associated with the occurrence of atrial fibrillation after coronary artery bypass graft surgery.

    Science.gov (United States)

    Yamac, Aylin Hatice; Kucukbuzcu, Sitki; Ozansoy, Mehmet; Gok, Ozlem; Oz, Kursat; Erturk, Mehmet; Yilmaz, Emre; Ersoy, Burak; Zeybek, Rahmi; Goktekin, Omer; Kilic, Ulkan

    2016-01-01

    Postoperative atrial fibrillation (POAF) is a potentially life-threatening complication after coronary artery bypass graft (CABG) surgery. The expression of the cardioprotective SIRT1 protein with its antioxidant activity is increased in cardiac tissue of patients suffering from POAF. So far, information is lacking about the relationship between SIRT1 regulating micro RNAs (miRs), SIRT1 protein and the occurrence of POAF. A total of 63 patients undergoing CABG were recruited, and biopsies were obtained from the right atrial appendage during cannulation. Postoperative, all patients were rhythm-monitored until discharge and randomized to POAF (n=20) or sinus rhythm (n=43). The expression of the micro RNAs miR-199a and miR-195 was quantified by real-time PCR. SIRT1 protein was detected by western blot analysis. The relative expression of miR-199a in the POAF group was significantly decreased compared to the control group (0.77±0.27 vs. 1.11±0.69, P=.022) Accordingly, SIRT 1 protein was significantly induced in tissue probes of patients with POAF (P<.001). Altered expression of the SIRT1 protein regulating miR-199a in human atrial tissue was found to be related to the occurrence of POAF, indicating its usefulness as a biomarker for cardiac surgery management. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Combined catheter ablation for atrial fibrillation and Watchman® left atrial appendage occlusion procedures: Five-year experience

    Directory of Open Access Journals (Sweden)

    Karen P. Phillips, MBBS

    2016-04-01

    Conclusions: Combined procedures of catheter ablation for AF and Watchman® LAA implant appear to be feasible and safe, with excellent rates of LAA occlusion achieved and an observed stroke rate of 0.5% per year during mid-term follow-up. Incomplete occlusion was associated with lower achieved device compression and was more frequently associated with suboptimal device position.

  3. Atrial fibrillation: a new look at an old arrhythmia

    NARCIS (Netherlands)

    Meijler, F.L.

    1983-01-01

    The ventricular rhythm during atrial fibrillation in human beings is random because the excitatory process of atrial fibrillation itself is almost certainly a random phenomenon. It remains random because A V junctional memory is too short to inftuence the sequence of conducted impulses . In human be

  4. 房颤对外周血CD34+造血祖细胞的影响 及SDF-1/CXCR4在心房中的表达%Effect of atrial fibrillation on human CD34 + hematopoietic progenitor cells in circulation and expression of SDF-1/CXCR4 in atrium

    Institute of Scientific and Technical Information of China (English)

    李佳; 葛海龙; 陈光远; 高倩萍; 孙俊峰; 李元十; 富路

    2011-01-01

    目的:研究不同类型的房颤(AF)对人外周血CD34+造血祖细胞(CD34+ HPCs)的影响,以及持续心房快速起搏犬心肌基质细胞衍生因子-1(SDF-1)及其受体CXCR4的表达,初步探讨CD34+ HPCs及SDF-1/CXCR4在AF时心肌损伤修复中的作用.方法:应用流式细胞术测定阵发性AF患者组(a=35)、持续性AF患者组(n=35)及窦性心律者对照组(n=30)外周血中CD34+ HPCs的百分含量;并对持续性AF患者组中24例患者成功进行体外直流电复律后48 h,测定外周血中CD34+ HPCs的百分含量.另外,将成年健康杂种犬13条随机分为两组:即快速起搏组(n=7)和假手术组(n=6),均开胸后于右心耳缝植AOO型起搏器,快速起搏组以400次/min起搏6周,假手术组不起搏.应用RT-PCR测定左心耳和左心房CXCR4mRNA的表达水平,用蛋白质免疫印迹法检测左心房SDF-1蛋白的表达.结果:持续性AF患者组外周血中CD34+ HPCs的百分含量明显高于阵发性AF患者组和对照组(P<0.05);而后两组间无差别.持续性AF患者成功进行体外直流电复律后48 h,外周血中CD34+ HPCs的百分含量较复律前明显下降(P<0.05).快速起搏组犬左心耳和左心房CXCR4mRNA表达的水平明显高于假手术组(P<0.05),左心耳增高16.7%,左心房增高18.8%:SDF-1蛋白质表达的水平亦明显高于假手术组(P<0.01).结论:持续性AF患者外周血中CD34 HPCs的数量增加;心房快速起搏犬心房SDF-1/CXCR4的表达增加.CD34+ HPCs和SDF1/CXCR4可能参与了持续性AF患者心房损伤时心肌组织的修复过程.%AIM: To investigate the effect of different kinds of atrial fibrillation (AF) on human CD34 + hematopoietic cells ( HPCs) in circulation and on myocardial expression of SDF-1 and its receptor CXCR4 in canines with lasting rapid atrial pacing and to explore the role of CD34 + HPCs and SDF-1/ CXCR4 in repairing atrium during AF. METHODS; Included in our study were 100 subjects (35 with paroxysmal AF, 35

  5. Atrial Strain and Strain Rate: A Novel Method for the Evaluation of Atrial Stunning

    Science.gov (United States)

    Ozkan, Hakan; Binici, Suleyman; Tenekecioglu, Erhan; Ari, Hasan; Bozat, Tahsin

    2016-01-01

    Background Atrial fibrillation (AF) is the most common arrhythmia seen in adults. Atrial stunning is defined as the temporary mechanical dysfunction of the atrial appendage developing after AF has returned to sinus rhythm (SR). Objectives We aimed to evaluate atrial contractile functions by strain and strain rate in patients with AF, following pharmacological and electrical cardioversion and to compare it with conventional methods. Methods This study included 41 patients with persistent AF and 35 age-matched control cases with SR. All the AF patients included in the study had transthoracic and transesophageal echocardiography performed before and after. Septum (SEPsSR), left atrium (LAsSR) and right atrium peak systolic strain rate (RAsSR) were defined as the maximum negative value during atrial contraction and septum (SEPε), left atrium (LAε) and right atrium peak systolic strain (RAε) was defined as the percentage of change. Parameters of two groups were compared. Results In the AF group, 1st hour and 24th hour LAε, RAε, SEPε, LAsSR, RAsSR, SEPsSR found to be significantly lower than in the control group (LAε: 2.61%±0.13, 3.06%±0.19 vs 6.45%±0.27, p<0.0001; RAε: 4.03%±0.38, 4.50%±0.47 vs 10.12%±0.64, p<0.0001; SEPε: 3.0%±0.22, 3.19%±0.15 vs 6.23%±0.49, p<0.0001; LAsSR: 0.61±0.04s-1, 0.75±0.04s-1 vs 1.35±0.04s-1, p<0.0001; RAsSR: 1.13±0.06s-1, 1.23±0.07s-1 vs 2.10±0.08s- 1, p<0.0001; SEPsSR: 0.76±0.04s- 1, 0.78±0.04s- 1 vs 1.42±0.06 s- 1, p<0.0001). Conclusion Atrial strain and strain rate parameters are superior to conventional echocardiographic parameters for the evaluation of atrial stunning in AF cases where SR has been achieved. PMID:27627221

  6. Effect of renal sympathetic denervation on atrial substrate remodeling in ambulatory canines with prolonged atrial pacing.

    Directory of Open Access Journals (Sweden)

    Xule Wang

    Full Text Available We have previously demonstrated that catheter-based renal sympathetic denervation (RSD could suppress atrial fibrillation (AF in canines with short-time rapid right atrial pacing (RAP. However, the role of renal denervation on atrial remodeling is unclear. The aim of the present study was to explore the long-term effect of RSD on the atrial remodeling during prolonged RAP. Twenty mongrel dogs were implanted with a high-frequency cardiac pacemaker with a transvenous lead inserted into the right atrial appendage. The dogs were divided into three groups: a sham-operated group (n = 6, the chronic RAP (CRAP group (n = 7, and the CRAP+RSD group (n = 7. In the CRAP+RSD group, a pacemaker was implanted 6 weeks after RSD was performed bilaterally for recovery. RAP was maintained for 5 weeks in CRAP group and CRAP+RSD group. The plasma levels of Angiotensin II and aldosterone were significantly increased in CRAP group compared with sham-operated group, but the increasing trend was inhibited in CRAP+RSD group compared with CRAP group (P<0.05. Similarly, RSD suppressed the increasing trend that prolonged RAP produced in the left atrial levels of ANP, TNF-α and IL-6. Compared with the sham-operated group, the CRAP group had significantly increased levels of caspase-3, bax and Cx40 whereas the level of Bcl-2 decreased (P<0.05. RSD markedly reduced the upregulation of caspase-3, bax and Cx40 and the downregulation of Bcl-2 expression compared with the CRAP group (P<0.05. Picric acid-sirius red staining study suggested that RSD could markedly alleviate the lesion degree of cardic fibrosis induced by CRAP (P<0.05. Immunohistochemistry results showed that the densities of TH- and GAP43- positive nerves were significantly elevated in the CRAP group compared with the sham-operated group, while RSD operation signicantly inhibited the these changes produced by CRAP. These findings suggest that renal denervation could suppress the atrial remodeling after

  7. Atrial fibrillation.

    Science.gov (United States)

    Bang, Casper N

    2013-10-01

    Atrial fibrillation (AF) is a common complication after myocardial infarction (MI) and new-onset AF has been demonstrated to be associated with adverse outcome and a large excess risk of death in both MI and aortic stenosis (AS) patients. Prevention of new-onset AF is therefore a potential therapeutic target in AS and MI patients. Lipid-lowering drugs, particularly statins, have anti-inflammatory and antioxidant properties that may prevent AF. Accordingly, statins are recommended as a class IIa recommendation for prevention of new-onset AF after coronary artery bypass grafting (CABG). However, this preventive effect has not been investigated on new-onset AF in asymptomatic patients with AS or a large scale first-time MI patient sample and data in patients not undergoing invasive cardiac interventions are limited. This PhD thesis was conducted at the Heart Centre, Rigshospitalet, Denmark, with the aim to investigate the three aforementioned questions and to add to the existing evidence of AF prevention with statins. This was done using three different settings: 1) a randomized patients sample of 1,873 from the Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) study, 2) a register patient sample of 97,499 with first-time MI, and 3) all published studies until beginning of June 2011 examining statin treatment on new-onset and recurrent AF in patients not undergoing cardiac surgery. This thesis revealed that statins did not lower the incidence or the time to new-onset AF in patients with asymptomatic AS. However, statin treatment showed an independently preventive effect on new-onset AF, including type-dependent effect and a trend to dosage-dependent effect. In addition, this thesis showed that good compliance to statin treatment was important to prevent new-onset AF. Finally, the meta-analysis in this PhD thesis showed a preventive effect in the observational studies although this effect was absent in the randomized controlled trials. Based on this PhD thesis

  8. Inhibition by atrial and brain natriuretic peptides of endothelin-1 secretion after stimulation with angiotensin II and thrombin of cultured human endothelial cells.

    Science.gov (United States)

    Kohno, M; Yasunari, K; Yokokawa, K; Murakawa, K; Horio, T; Takeda, T

    1991-01-01

    We examined the inhibition by atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) of endothelin-1 secretion stimulated by angiotensin II (ANGII) and thrombin using cultured human umbilical-vein endothelial cells. ANGII and thrombin dose-dependently stimulated immunoreactive (ir) endothelin-1 secretion. Human ANP(1-28) and human BNP-32 both inhibited such secretion in a dose-dependent way. Inhibition of this secretion by ANP and BNP was paralleled by an increase in the level of cyclic guanosine 5'-monophosphate (GMP). The addition of a cyclic GMP analogue, 8-bromo cyclic GMP, reduced this stimulated secretion. Rat ANP(5-25) was weaker than human ANP(1-28) at inhibiting ir-endothelin-1 secretion and increasing cyclic GMP in the cells. ir-Endothelin-1 in the medium consisted of two components separated by high pressure liquid chromatography; the major one corresponded to endothelin-1(1-21) and the minor one corresponded to big endothelin-1(1-38). Treatment with ANP and BNP did not affect this profile. These findings suggest that human ANP and BNP inhibit endothelin-1 secretion stimulated by ANGII and thrombin in these cells through a cyclic GMP-dependent process. Taken together with endothelin stimulation of ANP and BNP secretion from the heart, our results suggest the existence of a cardiac-endothelium feedback. PMID:1645748

  9. Growth differentiation factor-15 (GDF-15), novel biomarker for assessing atrial fibrosis in patients with atrial fibrillation and rheumatic heart disease.

    Science.gov (United States)

    Zhou, Yong-Ming; Li, Ming-Jiang; Zhou, Yan-Li; Ma, Le-Le; Yi, Xin

    2015-01-01

    Growth differentiation factor-15 (GDF-15) has been identified as a strong biomarker of cardiovascular diseases; however, no evidence are available concerning the relationship of GDF-15 and atrial fibrosis in patients with atrial fibrillation (AF) and rheumatic heart disease (RHD). Twenty patients with rheumatic heart disease were divided into two groups, 10 cases with AF and 10 cases with sinus rhythm (SR). Clinical data and blood samples were collected; left atrial appendage was taken by the surgeon in the process of valve replacement. Masson stained sections and mRNA levels of cardiac fibrosis biomarkers were used to determine the level of cardiac fibrosis, the expression level of GDF-15 was evaluated via immunohistochemistry, enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (PCR). Compared with SR group, more collagen deposited in the atrial tissue of AF group. The distribution of GDF-15 in the AF group was significantly higher than SR group (Pfibrosis. GDF-15 might involve in the development and maintenance of atrial fibrosis in patients with atrial fibrillation and rheumatic heart disease, and GDF-15 could be used as a novel biomarker to evaluate myocardial fibrosis in the future.

  10. Effect of Low-level Vagus Nerve Stimulation on Cardiac Remodeling in a Rapid Atrial Pacing-induced Canine Model of Atrial Fibrillation.

    Science.gov (United States)

    Lu, Yanmei; Sun, Juan; Zhou, Xianhui; Zhang, Ling; Ma, Mei; Tang, Baopeng

    2016-03-01

    The aim of this study was to establish a rapid atrial pacing-induced canine model of atrial fibrillation in studying the effects of low-level vagus nerve stimulation (LLVNS) on atrial fibrillation and the underlying mechanisms for those effects. Adult beagle dogs were randomly assigned to 3 groups: a sham operation group (sham group), a fast left atrial appendage 12-hour pacing group (pacing group), and a 12-hour pacing + LLVNS group (LLVNS group). All dogs underwent tests for their left and right atrial effective refractory period at various time points, after which they were killed, and samples of atrial and anterior right ganglionated plexi tissue were removed and microscopically examined. As pacing times increased, the mean effective refractory period in the pacing group became significantly shortened. The pacing group and the LLVNS group did show significant differences (P nerve growth factor and neurturin (NRTN) in the sham group and the LLVNS group were lower than those in the pacing group (nerve growth factor in 3 groups were (36.35 ± 6.18) × 1000, (86.35 ± 5.63) × 1000, and (40.50 ± 7.24) × 1000 μm²/mm², P nerves.

  11. Minimally invasive surgery for atrial fibrillation.

    Science.gov (United States)

    Zembala, Michael O; Suwalski, Piotr

    2013-11-01

    Atrial fibrillation (AF) remains the most common cardiac arrhythmia, affecting nearly 2% of the general population worldwide. Minimally invasive surgical ablation remains one of the most dynamically evolving fields of modern cardiac surgery. While there are more than a dozen issues driving this development, two seem to play the most important role: first, there is lack of evidence supporting percutaneous catheter based approach to treat patients with persistent and long-standing persistent AF. Paucity of this data offers surgical community unparalleled opportunity to challenge guidelines and change indications for surgical intervention. Large, multicenter prospective clinical studies are therefore of utmost importance, as well as honest, clear data reporting. Second, a collaborative methodology started a long-awaited debate on a Heart Team approach to AF, similar to the debate on coronary artery disease and transcatheter valves. Appropriate patient selection and tailored treatment options will most certainly result in better outcomes and patient satisfaction, coupled with appropriate use of always-limited institutional resources. The aim of this review, unlike other reviews of minimally invasive surgical ablation, is to present medical professionals with two distinctly different, approaches. The first one is purely surgical, Standalone surgical isolation of the pulmonary veins using bipolar energy source with concomitant amputation of the left atrial appendage-a method of choice in one of the most important clinical trials on AF-The Atrial Fibrillation Catheter Ablation Versus Surgical Ablation Treatment (FAST) Trial. The second one represents the most complex approach to this problem: a multidisciplinary, combined effort of a cardiac surgeon and electrophysiologist. The Convergent Procedure, which includes both endocardial and epicardial unipolar ablation bonds together minimally invasive endoscopic surgery with electroanatomical mapping, to deliver best of the

  12. Selected Disorders of Skin Appendages--Acne, Alopecia, Hyperhidrosis.

    Science.gov (United States)

    Vary, Jay C

    2015-11-01

    This article reviewed some of the more common diseases of the skin appendages that are encountered in medicine: hyperhidrosis, acne, AA, FPHL, AGA, and TE. The pathophysiology behind the conditions and their treatments were discussed so that the clinician can make logical therapeutic choices for their affected patients.

  13. Primary ciliogenesis requires the distal appendage component Cep123

    Directory of Open Access Journals (Sweden)

    James E. Sillibourne

    2013-04-01

    Primary cilium formation is initiated at the distal end of the mother centriole in a highly co-ordinated manner. This requires the capping of the distal end of the mother centriole with a ciliary vesicle and the anchoring of the basal body (mother centriole to the cell cortex, both of which are mediated by the distal appendages. Here, we show that the distal appendage protein Cep123 (Cep89/CCDC123 is required for the assembly, but not the maintenance, of a primary cilium. In the absence of Cep123 ciliary vesicle formation fails, suggesting that it functions in the early stages of primary ciliogenesis. Consistent with such a role, Cep123 interacts with the centriolar satellite proteins PCM-1, Cep290 and OFD1, all of which play a role in primary ciliogenesis. These interactions are mediated by a domain in the C-terminus of Cep123 (400–783 that overlaps the distal appendage-targeting domain (500–600. Together, the data implicate Cep123 as a new player in the primary ciliogenesis pathway and expand upon the role of the distal appendages in this process.

  14. Recurrence quantification analysis applied to spatiotemporal pattern analysis in high-density mapping of human atrial fibrillation.

    Science.gov (United States)

    Zeemering, Stef; Bonizzi, Pietro; Maesen, Bart; Peeters, Ralf; Schotten, Ulrich

    2015-01-01

    Spatiotemporal complexity of atrial fibrillation (AF) patterns is often quantified by annotated intracardiac contact mapping. We introduce a new approach that applies recurrence plot (RP) construction followed by recurrence quantification analysis (RQA) to epicardial atrial electrograms, recorded with a high-density grid of electrodes. In 32 patients with no history of AF (aAF, n=11), paroxysmal AF (PAF, n=12) and persistent AF (persAF, n=9), RPs were constructed using a phase space electrogram embedding dimension equal to the estimated AF cycle length. Spatial information was incorporated by 1) averaging the recurrence over all electrodes, and 2) by applying principal component analysis (PCA) to the matrix of embedded electrograms and selecting the first principal component as a representation of spatial diversity. Standard RQA parameters were computed on the constructed RPs and correlated to the number of fibrillation waves per AF cycle (NW). Averaged RP RQA parameters showed no correlation with NW. Correlations improved when applying PCA, with maximum correlation achieved between RP threshold and NW (RR1%, r=0.68, p <; 0.001) and RP determinism (DET, r=-0.64, p <; 0.001). All studied RQA parameters based on the PCA RP were able to discriminate between persAF and aAF/PAF (DET persAF 0.40 ± 0.11 vs. 0.59 ± 0.14/0.62 ± 0.16, p <; 0.01). RP construction and RQA combined with PCA provide a quick and reliable tool to visualize dynamical behaviour and to assess the complexity of contact mapping patterns in AF.

  15. Gene signatures of postoperative atrial fibrillation in atrial tissue after coronary artery bypass grafting surgery in patients receiving β-blockers.

    Science.gov (United States)

    Kertai, Miklos D; Qi, Wenjing; Li, Yi-Ju; Lombard, Frederick W; Liu, Yutao; Smith, Michael P; Stafford-Smith, Mark; Newman, Mark F; Milano, Carmelo A; Mathew, Joseph P; Podgoreanu, Mihai V

    2016-03-01

    Atrial tissue gene expression profiling may help to determine how differentially expressed genes in the human atrium before cardiopulmonary bypass (CPB) are related to subsequent biologic pathway activation patterns, and whether specific expression profiles are associated with an increased risk for postoperative atrial fibrillation (AF) or altered response to β-blocker (BB) therapy after coronary artery bypass grafting (CABG) surgery. Right atrial appendage (RAA) samples were collected from 45 patients who were receiving perioperative BB treatment, and underwent CABG surgery. The isolated RNA samples were used for microarray gene expression analysis, to identify probes that were expressed differently in patients with and without postoperative AF. Gene expression analysis was performed to identify probes that were expressed differently in patients with and without postoperative AF. Gene set enrichment analysis (GSEA) was performed to determine how sets of genes might be systematically altered in patients with postoperative AF. Of the 45 patients studied, genomic DNA from 42 patients was used for target sequencing of 66 candidate genes potentially associated with AF, and 2,144 single-nucleotide polymorphisms (SNPs) were identified. We then performed expression quantitative trait loci (eQTL) analysis to determine the correlation between SNPs identified in the genotyped patients, and RAA expression. Probes that met a false discovery rate<0.25 were selected for eQTL analysis. Of the 17,678 gene expression probes analyzed, 2 probes met our prespecified significance threshold of false discovery rate<0.25. The most significant probe corresponded to vesicular overexpressed in cancer - prosurvival protein 1 gene (VOPP1; 1.83 fold change; P=3.47×10(-7)), and was up-regulated in patients with postoperative AF, whereas the second most significant probe, which corresponded to the LOC389286 gene (0.49 fold change; P=1.54×10(-5)), was down-regulated in patients with

  16. The developing pulmonary veins and left atrium: implications for ablation strategy for atrial fibrillation.

    Science.gov (United States)

    Sherif, Hisham M F

    2013-11-01

    The majority of cases of atrial fibrillation (AF) are the result of triggers originating in the area of the pulmonary veins. The reason for the predilection for that area remains unclear. We sought to examine the different mechanisms responsible for this observation through an extensive search of the medical literature, examining the development of the pulmonary veins, genetics of AF and left to -right cardiac chamber differentiation. Results confirm that the LAA is anatomically and embryologically different from other areas of the atrial walls and develops under distinct genetic and transcriptional pathways. Findings support an ablation strategy whose primary focus should be the creation of a 'box' lesion set, plus additional lines to prevent propagation to the left atrial appendage, the isthmus of the left atrium and the right atrium are likely to be more effective than simple pulmonary vein isolation.

  17. Managing atrial fibrillation in the very elderly patient: challenges and solutions

    Directory of Open Access Journals (Sweden)

    Karamichalakis N

    2015-10-01

    Full Text Available Nikolaos Karamichalakis, Konstantinos P Letsas, Konstantinos Vlachos, Stamatis Georgopoulos, Athanasios Bakalakos, Michael Efremidis, Antonios Sideris Laboratory of Cardiac Electrophysiology, "Evangelismos" General Hospital of Athens, Athens, Greece Abstract: Atrial fibrillation (AF is the most common arrhythmia affecting elderly patients. Management and treatment of AF in this rapidly growing population of older patients involve a comprehensive assessment that includes comorbidities, functional, and social status. The cornerstone in therapy of AF is thromboembolic protection. Anticoagulation therapy has evolved, using conventional or newer medications. Percutaneous left atrial appendage closure is a new invasive procedure evolving as an alternative to systematic anticoagulation therapy. Rate or rhythm control leads to relief in symptoms, fewer hospitalizations, and an improvement in quality of life. Invasive methods, such as catheter ablation, are the new frontier of treatment in maintaining an even sinus rhythm in this particular population. Keywords: elderly, atrial fibrillation, anticoagulation, drugs, catheter ablation

  18. Alterations in gene expression of proteins involved in the calcium handling in patients with atrial fibrillation

    NARCIS (Netherlands)

    Van Gelder, IC; Brundel, BJJM; Henning, RH; Tuinenburg, AE; Tieleman, RG; Deelman, L; Grandjean, JG; De Kam, PJ; Van Gilst, WH; Crijns, HJGM

    1999-01-01

    Gene Expression in Human Atrial Fibrillation, Introduction: Atrial fibrillation (AF) leads to a loss of atrial contraction within hours to days. During persistence of AF, cellular dedifferentiation and hypertrophy occur, eventually resulting in degenerative changes and cell death, Abnormalities in t

  19. Effect of ablation of complex fractionated atrial electrogram on vagal modulation in dogs

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shu-long; YANG Yan-zong; DONG Ying-xue; JIANG Peng; GAO Lian-jun; CHA Yong-mei; Douglas L.Packer; XIA Yun-long; YIN Xiao-meng; CHANG Dong

    2010-01-01

    Background Clinical observations have shown that the complex fractionated atrial electrogram (CFAE) associates with ganglionated plexus activity in the cardiac autonomic nervous system. This study aimed to investigate the impact of CFAE ablation on vagal modulation to atria and vulnerability to develop atrial fibrillation (AF).Methods Ten adult mongrel dogs were involved. Cervical sympathovagal trunks were decentralized and sympathetic effects were blocked. CFAE was color tagged on the atrial 3-dimensional image and ablated during AF induced by S1S2 programmed stimulation plus sympathovagal trunk stimulation. Atrial effective refractory period (ERP) and vulnerability window (VW) of AF were measured on baseline and at vagal stimulation at 4 atrium sites. Serial tissue sections from ablative and control specimens received hematoxylin and eosin staining for microscopic examination.Results Most CFAE areas were localized at the right superior pulmonary quadrant, distal coronary sinus (CSd)quadrant, and proximal coronary sinus (CSp) quadrant (21.74%, separately). Sinus rhythm cycle length (SCL) shortening did not decrease significantly after ablation at the sites, including right atrial appendage, left atrial appendage, CSd, and CSp (P >0.05). ERP shortening during vagal stimulation significantly decreased after ablation (P <0.01); the VW to vagal stimulation significantly decreased after ablation (P <0.05). The architecture of individual ganglia altered after ablation.Conclusions CFAE has an autonomic basis in dogs. The decreased SCL and ERP shortening to vagal stimulation after CFAE ablation demonstrate that CFAE ablation attenuates vagal modulation to the atria, thereby suppressing AF mediated by enhanced vagal activity. CFAE ablation could suppress AF mediated by enhanced vagal activity.

  20. Left atrial volume index

    DEFF Research Database (Denmark)

    Poulsen, Mikael K; Dahl, Jordi S; Henriksen, Jan Erik;

    2013-01-01

    To determine the prognostic importance of left atrial (LA) dilatation in patients with type 2 diabetes (T2DM) and no history of cardiovascular disease.......To determine the prognostic importance of left atrial (LA) dilatation in patients with type 2 diabetes (T2DM) and no history of cardiovascular disease....

  1. Left atrial strain: a new predictor of thrombotic risk and successful electrical cardioversion

    Directory of Open Access Journals (Sweden)

    Cátia Costa

    2016-06-01

    Full Text Available Background: Left atrial deformation (LAD parameters are new markers of atrial structural remodelling that seem to be affected in atrial fibrillation (AF and atrial flutter (AFL. This study aimed to determine whether LAD can identify patients with a higher risk of thrombosis and unsuccessful electrical cardioversion (ECV. Methods: Retrospective study including 56 patients with AF or AFL undergoing ECV, with previous transthoracic (TTE and transoesophageal echocardiography (TEE studies. Echocardiographic parameters analysed were as follows: left ventricle function, left atrium (LA dimensions, LAD parameters (positive and negative strain peaks, left atrial appendage (LAA filling and emptying velocities and the presence of thrombi. Strain values were analysed according to thrombotic risk and success of ECV. Results: Lower mean values of peak-positive strain (PPS in patients with prothrombotic velocities (<25 cm/s and a higher incidence of thrombi in LAA were observed compared with those with normal velocities. Multivariate analysis revealed PPS normalised by LA maximum volume indexed by body surface area (BSA to be associated with prothrombotic risk (odds ratio 0.000 (95% CI: 0.000–0.243, P 0.017, regardless of CHADs2VASC score. Peak-negative strain normalised by LA volumes indexed by BSA were associated with unsuccessful ECV. Conclusions: Atrial deformation parameters identify AF and AFL patients with a high risk of thrombosis and unsuccessful ECV. Therefore, these new parameters should be included in anticoagulation management and rhythm vs rate control strategies.

  2. An unsuspected metabolic role for atrial natriuretic peptides: the control of lipolysis, lipid mobilization, and systemic nonesterified fatty acids levels in humans.

    Science.gov (United States)

    Lafontan, Max; Moro, Cédric; Sengenes, Coralie; Galitzky, Jean; Crampes, François; Berlan, Michel

    2005-10-01

    In normal and obese humans, lipid mobilization and systemic nonesterified fatty acid levels are thought to be acutely controlled by catecholamines (ie, epinephrine and norepinephrine) and insulin. Natriuretic peptides (NPs) are known to play a key role in the regulation of salt and water balance and blood pressure homeostasis. They are involved in the pathophysiology of hypertension and heart failure. NPs have recently been found to exert potent lipolytic effects (ie, activating the breakdown of stored triacylglycerols) in isolated human fat cells and to promote lipid mobilization in vivo. Atrial natriuretic peptide increases the intracellular 3', 5'-cyclic guanosine monophosphate (cGMP) concentration which activates cGMP-dependent protein kinase leading to perilipin and hormone-sensitive lipase phosphorylation and lipolysis. NPs promote lipid mobilization when administered intravenously. NPs are also responsible for the residual lipid-mobilizing action observed under oral beta-blockade in subjects performing physical exercise. NPs are therefore novel factors which may open promising research pathways to explain the control of lipid mobilization in physiological and pathological conditions. The metabolic impact of altered production and circulation of NPs remains to be established. The potential influence of NPs on the development of lipid disorders, obesity-related cardiovascular events, and cardiac cachexia will be discussed in this review.

  3. Clinical Study of Recombinant Human atrial Natriuretic Peptide in Treatment of Acute Heart Failure%重组人心钠肽治疗急性心力衰竭的临床研究

    Institute of Scientific and Technical Information of China (English)

    贺宇峰

    2015-01-01

    目的:探讨重组人心钠肽治疗急性心力衰竭疗效。方法:对自2011年5月~2013年2月我院收治的急性心力衰竭患者应用重组人心钠肽治疗,于用药前后监测患者的血流动力学参数。结果:66例患者59例症状缓解,显效27例,有效32例,无效7例,有效率89.39%。结论:重组人心钠肽是治疗急性心力衰竭疗效可靠的药物,安全性高。%Objective:To investigate the recombinant human atrial natriuretic peptide in treatment of acute heart failure efficacy .Meth-ods:the application of recombinant human atrial natriuretic peptide in patients with acute heart failure treatment since 2011 May to 2013 February in our hospital , in hemodynamic parameters monitoring of patients before and after treatment .Results:of the 66 patients, 59 ca-ses of remission, 27 cases markedly effective, effective 32 cases, invalid 7 cases, efficiency of 89.39%.Conclusion:recombinant human atrial natriuretic peptide drugs and reliable effect in the treatment of acute heart failure , high safety.

  4. A Rare Cause of Acute Abdominal Pain: Primary Appendagitis Epiploica

    Directory of Open Access Journals (Sweden)

    Tarkan Ergun

    2014-03-01

    Primary appendagitis epiploica – one of the causes of acute abdominal pain – is a self-limited rare benign inflammatory condition involving the colonic epiploic appendages. Their therapy is conservative and clinically mimics other conditions requiring surgery such as acute diverticulitis or appendicitis. However, being a quite rare condition is the reason they are usually neglected by both the surgeon and the radiologist. However the computed tomography (CT findings are rather characteristic and pathognomonic. Thus, to consider CT as the diagnostic modality of choice is extremely important in order to diagnose the condition and to avoid unnecessary surgical interventions.             This is a paper reporting an acute abdominal pain case of primary appendicitis epiploica diagnosed using computed tomography. 

  5. Magnetic resonance imaging of epiploic appendagitis in children.

    Science.gov (United States)

    Boscarelli, Alessandro; Frediani, Simone; Ceccanti, Silvia; Falconi, Ilaria; Masselli, Gabriele; Casciani, Emanuele; Cozzi, Denis A

    2016-12-01

    In children, epiploic appendagitis has been seldom reported. We describe two children with clinical presentations mimicking appendicitis. A correct diagnosis was eventually achieved by magnetic resonance imaging (MRI) and confirmed at laparoscopy in the initial case. Our preliminary experience suggests that MRI is a valid and non-invasive alternative to computed tomography for characterization of unusual causes of pediatric abdominal pain in the acute hospital care setting. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Evo-Devo of Amniote Integuments and Appendages

    OpenAIRE

    Wu, Ping; Hou, Lianhai; Plikus, Maksim; Hughes, Michael; Scehnet, Jeffrey; Suksaweang, Sanong; Widelitz, Randall B.; Jiang, Ting-Xin; Chuong, Cheng-Ming

    2004-01-01

    Integuments form the boundary between an organism and the environment. The evolution of novel developmental mechanisms in integuments and appendages allows animals to live in diverse ecological environments. Here we focus on amniotes. The major achievement for reptile skin is an adaptation to the land with the formation of a successful barrier. The stratum corneum enables this barrier to prevent water loss from the skin and allowed amphibian/reptile ancestors to go onto the land. Overlapping ...

  7. Kodymirus and the case for convergence of raptorial appendages in Cambrian arthropods

    Science.gov (United States)

    Lamsdell, James C.; Stein, Martin; Selden, Paul A.

    2013-09-01

    Kodymirus vagans Chlupáč and Havlíček in Sb Geol Ved Paleontol 6:7-20, 1965 is redescribed as an aglaspidid-like arthropod bearing a single pair of enlarged raptorial appendages, which are shown to be the second cephalic appendage. A number of early Palaeozoic arthropods, recognized from predominantly Cambrian Konservat-Lagerstätten, are known to have borne single pairs of large raptorial appendages. They are well established for the iconic yet problematic anomalocarids, the common megacheirans, and the ubiquitous bivalved Isoxys. Further taxa, such as fuxianhuiids and Branchiocaris, have been reported to have single pairs of specialized cephalic appendages, i.e., appendages differentiated from a largely homonomous limbs series, members of which act in metachronal motion. The homology of these raptorial appendages across these Cambrian arthropods has often been assumed, despite differences in morphology. Thus, anomalocaridids, for instance, have long multiarticulate "frontal appendages" consisting of many articles bearing an armature of paired serial spines, while megacheirans and Isoxys have short "great appendages" consisting of few articles with well-developed endites or elongate fingers. Homology of these appendages would require them to belong to the same cephalic segment. We argue based on morphological evidence that, to the contrary, the raptorial appendages of some of these taxa can be shown to belong to different cephalic segments and are the result of convergence in life habits. K. vagans is yet another important example for this, representing an instance for this morphology from a marginal marine environment.

  8. [Epiploic appendagitis: a rare cause of abdominal pain].

    Science.gov (United States)

    García-Marín, Andrés; Nofuentes-Riera, Carmen; Mella-Laborde, Mario; Pérez-López, Mercedes; Pérez-Bru, Susana; Rubio-Cerdido, José María

    2014-01-01

    Epiploic appendagitis is an atypical cause of abdominal pain whose knowledge could avoid diagnostic or treatment errors. Diagnosis has been performed with abdominal ultrasound or tomography with the only treatment being nonsteroidal anti-inflammatory drugs. To analyze patients diagnosed in our hospital. We performed a 4-year retrospective and descriptive study (March 2009-March 2013) of patients diagnosed with epiploic appendagitis in our hospital. Seventeen patients were included, 14 females and three males with a median age of 57 years. Symptom delay was 72 h. Abdominal pains were located in the left lower quadrant in 64.7% and right lower quadrant in 35.3% of patients. Blood test demonstrated leukocytes 6,300 (5,000-9,500), neutrophils 61.6% (57-65.8), and C reactive protein 1.5 (0.85-2.92). Diagnosis was confirmed with abdominal ultrasound or tomography in 88.2% and intraoperatively in 11.8%. Epiploic appendagitis was more frequent in women. Abdominal pain was located in the lower quadrant, more predominant in left than right. Blood tests were normal except for increased levels of C-reactive protein. Diagnosis was made mostly preoperatively due to imaging tests, avoiding unnecessary surgical intervention.

  9. The internodal atrial myocardium.

    Science.gov (United States)

    Anderson, R H; Ho, S Y; Smith, A; Becker, A E

    1981-09-01

    The anatomical substrates of internodal conduction have long been a contentious topic. Debated first by the German Pathological Society in 1910, the consensus of established opinion for over half a century was that conduction between sinus and atrioventricular nodes occurred through plain myocardium. This was a conclusion supported by Truex in 1961. Despite his restatement of this fact in 1976, it has become fashionable to describe internodal conduction as being mediated by specialized internodal pathways. To reinvestigate this problem we studied 22 human fetal and 32 human infant hearts. In each case it was possible to cut the atrial tissues as a single block of tissue and to examine serial sections through the internodal myocardium. The sinus node, atrioventricular node, and segments of atrioventricular ring specialized tissue were recognized as specialized tissue using the light microscope in each heart. In contrast, there was nothing "special" about the myocardium between the nodes, nor was it possible to recognize tracts on the basis of either histological appearance or cellular architecture. It is concluded that, from the standpoint of light microscopy, there is no evidence whatsoever to support the purported concept of specialized anatomical substrates for internodal conduction.

  10. Differential regulation of atrial natriuretic peptide- and adrenergic receptor-dependent lipolytic pathways in human adipose tissue.

    Science.gov (United States)

    Moro, Cédric; Polak, Jan; Richterova, Blanka; Sengenès, Coralie; Pelikanova, Terezie; Galitzky, Jean; Stich, Vladimir; Lafontan, Max; Berlan, Michel

    2005-01-01

    The aim of the study was to investigate the regulation affecting the recently described atrial natriuretic peptide (ANP)-dependent lipolytic pathway in comparison with the adrenergic lipolytic cascade. We studied in vivo the effect of a euglycemic-hyperinsulinemic clamp on the changes occurring in the extracellular glycerol concentration (EGC) of subcutaneous adipose tissue (SCAT) during ANP or epinephrine perfusion in a microdialysis probe. Homologous desensitization and the incidence of hyperinsulinemia on the ANP- and catecholaminergic-dependent control of lipolysis were also investigated in vitro on fat cells from SCAT. When perfused in SCAT, epinephrine and ANP promoted an increase in EGC; the EGC increase was significantly lower during the clamp. The reduction of epinephrine-induced lipolysis was limited (18%) when phentolamine (an alpha(2)-adrenergic receptor [AR] antagonist) was perfused together with epinephrine. Unlike the effect of epinephrine, the response to ANP observed during the second perfusion was reduced by 32%. The increase in extracellular guanosine 3',5' -cyclic monophosphate concentration, which reflects ANP activity, was also reduced during the second perfusion. Desensitization of the lipolytic effects of ANP was observed in vitro after a 2-hour period of recovery, while the effects of alpha(2)-AR agonist or of epinephrine were unchanged. Insulin was without any effect on ANP-induced lipolysis and alpha(2)-AR-mediated antilipolysis, while it reduced beta-AR-induced lipolysis. The ANP-dependent lipolytic pathway undergoes desensitization in vitro and in situ. Insulin had no inhibitory effect on either ANP- or alpha(2)-AR-dependent pathways, while it counteracted the beta-AR pathway.

  11. Atrial natriuretic peptide contribution to lipid mobilization and utilization during head-down bed rest in humans.

    Science.gov (United States)

    Moro, Cédric; Pillard, Fabien; de Glisezinski, Isabelle; Crampes, Francois; Thalamas, Claire; Harant, Isabelle; Marques, Marie-Adeline; Lafontan, Max; Berlan, Michel

    2007-08-01

    Head-down bed rest (HDBR) increases plasma levels of atrial natriuretic peptide (ANP) and decreases norepinephrine levels. We previously demonstrated that ANP promotes lipid mobilization and utilization, an effect independent of sympathetic nervous system activation, when infused into lean healthy men at pharmacological doses. The purpose of the present study was to demonstrate that a physiological increase in ANP contributes to lipid mobilization and oxidation in healthy young men. Eight men were positioned for 4 h in a sitting (control) or in a HDBR position. Indexes of lipid mobilization and hormonal changes were measured in plasma. Extracellular glycerol, an index of lipolysis, was determined in subcutaneous adipose tissue (SCAT) with a microdialysis technique. A twofold increase in plasma ANP concentration was observed after 60 min of HDBR, and a plateau was maintained thereafter. Plasma norepinephrine decreased by 30-40% during HDBR, while plasma insulin and glucose levels did not change. The level of plasma nonesterified fatty acids was higher during HDBR. SCAT lipolysis, as reflected by interstitial glycerol, as well as interstitial cGMP, the second messenger of the ANP pathway, increased during HDBR. This was associated with an increase in blood flow observed throughout HDBR. Significant changes in respiratory exchange ratio and percent use of lipid and carbohydrate were seen only after 3 h of HDBR. Thus the proportion of lipid oxidized increased by 40% after 3 h of HDBR. The rise in plasma ANP during HDBR was associated with increased lipolysis in SCAT and whole body lipid oxidation. In this physiological setting, independent of increasing catecholamines, our study suggests that ANP contributes to lipid mobilization and oxidation in healthy young men.

  12. Effects of beta-blockade on atrial and atrioventricular nodal refractoriness, and atrial fibrillatory rate during atrial fibrillation in pigs

    NARCIS (Netherlands)

    van den Berg, MP; van de Ven, LLM; Witting, W; Crijns, JGM; Haaksma, J; Bel, KJ; de Langen, CDJ; Lie, KI

    1997-01-01

    Despite their widespread use in atrial fibrillation, the effects of beta-adrenoceptor blockers on atrial and atrioventricular (AV) nodal refractoriness, and atrial fibrillatory rate during atrial fibrillation have been incompletely characterised. In particular, it is unknown whether additional sodiu

  13. Surgery for atrial fibrillation.

    Science.gov (United States)

    Lawrance, Christopher P; Henn, Matthew C; Damiano, Ralph J

    2014-11-01

    Atrial fibrillation is the most common cardiac arrhythmia, and its treatment options include drug therapy or catheter-based or surgical interventions. The surgical treatment of atrial fibrillation has undergone multiple evolutions over the last several decades. The Cox-Maze procedure went on to become the gold standard for the surgical treatment of atrial fibrillation and is currently in its fourth iteration (Cox-Maze IV). This article reviews the indications and preoperative planning for performing a Cox-Maze IV procedure. This article also reviews the literature describing the surgical results for both approaches including comparisons of the Cox-Maze IV to the previous cut-and-sew method.

  14. Hierarchical assembly of centriole subdistal appendages via centrosome binding proteins CCDC120 and CCDC68.

    Science.gov (United States)

    Huang, Ning; Xia, Yuqing; Zhang, Donghui; Wang, Song; Bao, Yitian; He, Runsheng; Teng, Junlin; Chen, Jianguo

    2017-04-19

    In animal cells, the centrosome is the main microtubule-organizing centre where microtubules are nucleated and anchored. The centriole subdistal appendages (SDAs) are the key structures that anchor microtubules in interphase cells, but the composition and assembly mechanisms of SDAs are not well understood. Here, we reveal that centrosome-binding proteins, coiled-coil domain containing (CCDC) 120 and CCDC68 are two novel SDA components required for hierarchical SDA assembly in human cells. CCDC120 is anchored to SDAs by ODF2 and recruits CEP170 and Ninein to the centrosome through different coiled-coil domains at its N terminus. CCDC68 is a CEP170-interacting protein that competes with CCDC120 in recruiting CEP170 to SDAs. Furthermore, CCDC120 and CCDC68 are required for centrosome microtubule anchoring. Our findings elucidate the molecular basis for centriole SDA hierarchical assembly and microtubule anchoring in human interphase cells.

  15. Hierarchical assembly of centriole subdistal appendages via centrosome binding proteins CCDC120 and CCDC68

    Science.gov (United States)

    Huang, Ning; Xia, Yuqing; Zhang, Donghui; Wang, Song; Bao, Yitian; He, Runsheng; Teng, Junlin; Chen, Jianguo

    2017-01-01

    In animal cells, the centrosome is the main microtubule-organizing centre where microtubules are nucleated and anchored. The centriole subdistal appendages (SDAs) are the key structures that anchor microtubules in interphase cells, but the composition and assembly mechanisms of SDAs are not well understood. Here, we reveal that centrosome-binding proteins, coiled-coil domain containing (CCDC) 120 and CCDC68 are two novel SDA components required for hierarchical SDA assembly in human cells. CCDC120 is anchored to SDAs by ODF2 and recruits CEP170 and Ninein to the centrosome through different coiled-coil domains at its N terminus. CCDC68 is a CEP170-interacting protein that competes with CCDC120 in recruiting CEP170 to SDAs. Furthermore, CCDC120 and CCDC68 are required for centrosome microtubule anchoring. Our findings elucidate the molecular basis for centriole SDA hierarchical assembly and microtubule anchoring in human interphase cells. PMID:28422092

  16. Induction of atrial fibrillation by neutrophils critically depends on CD11b/CD18 integrins.

    Directory of Open Access Journals (Sweden)

    Kai Friedrichs

    Full Text Available BACKGROUND: Recent observational clinical and ex-vivo studies suggest that inflammation and in particular leukocyte activation predisposes to atrial fibrillation (AF. However, whether local binding and extravasation of leukocytes into atrial myocardium is an essential prerequisite for the initiation and propagation of AF remains elusive. Here we investigated the role of atrial CD11b/CD18 mediated infiltration of polymorphonuclear neutrophils (PMN for the susceptibility to AF. METHODS AND RESULTS: C57bl/6J wildtype (WT and CD11b/CD18 knock-out (CD11b(-/- mice were treated for 14 days with subcutaneous infusion of angiotensin II (Ang II, a known stimulus for PMN activation. Atria of Ang II-treated WT mice were characterized by increased PMN infiltration assessed in immunohistochemically stained sections. In contrast, atrial sections of CD11b(-/- mice lacked a significant increase in PMN infiltration upon Ang II infusion. PMN infiltration was accompanied by profoundly enhanced atrial fibrosis in Ang II treated WT as compared to CD11b(-/- mice. Upon in-vivo electrophysiological investigation, Ang II treatment significantly elevated the susceptibility for AF in WT mice if compared to vehicle treated animals given an increased number and increased duration of AF episodes. In contrast, animals deficient of CD11b/CD18 were entirely protected from AF induction. Likewise, epicardial activation mapping revealed decreased electrical conduction velocity in atria of Ang II treated WT mice, which was preserved in CD11b(-/- mice. In addition, atrial PMN infiltration was enhanced in atrial appendage sections of patients with persistent AF as compared to patients without AF. CONCLUSIONS: The current data critically link CD11b-integrin mediated atrial PMN infiltration to the formation of fibrosis, which promotes the initiation and propagation of AF. These findings not only reveal a mechanistic role of leukocytes in AF but also point towards a potential novel

  17. What Is Atrial Fibrillation?

    Science.gov (United States)

    ... regular beat. Certain cells in your heart make electric signals that cause the heart to contract and pump ... read your ECG to find out if the electric signals are normal. In atrial fibrillation (AFib), the heart’s ...

  18. Right coronary artery perforation by an active-fixation atrial pacing lead resulting in life-threatening tamponade.

    Science.gov (United States)

    Nakagawa, Eiichiro; Abe, Yukio; Komatsu, Ryushi; Naruko, Takahiko; Itoh, Akira

    2015-10-01

    Cardiac tamponade resulting from perforation of a cardiac chamber is a relatively rare complication of pacemaker implantation. We report the first case of perforation of the right coronary artery related to the implantation of a screw-in atrial pacing lead, presenting as life-threatening cardiac tamponade. We report the case of a 72-year-old woman with complete atrioventricular block and dyspnea on exertion. A permanent pacemaker was implanted with bipolar Medtronic active-fixation leads positioned in the right atrial appendage and at the right ventricular basal septum without any difficulty. Approximately 3.5 h after the procedure, the patient complained of nausea, and the systolic blood pressure decreased to less than 60 mmHg. Echocardiography revealed a large pericardial effusion. Because the effects of pericardiocentesis lasted for less than an hour, the patient underwent a thoracotomy. After evacuation of a massive hemopericardium, bright red blood was seen gushing out from the right coronary artery, which was located on the opposite site of the right atrial appendage where a small portion of the screw tip was observed to be penetrating the atrial wall. The right coronary artery perforation was repaired using autologous pericardium-reinforced 7-0 prolene mattress sutures. Perforation of the right coronary artery is a potential complication and should be part of the differential diagnosis of cardiac tamponade after pacemaker implantation.

  19. Mutational analysis of βCOP (Sec26p identifies an appendage domain critical for function

    Directory of Open Access Journals (Sweden)

    Cerione Richard A

    2008-01-01

    Full Text Available Abstract Background The appendage domain of the γCOP subunit of the COPI vesicle coat bears a striking structural resemblance to adaptin-family appendages despite limited primary sequence homology. Both the γCOP appendage domain and an equivalent region on βCOP contain the FxxxW motif; the conservation of this motif suggested the existence of a functional appendage domain in βCOP. Results Sequence comparisons in combination with structural prediction tools show that the fold of the COOH-terminus of Sec26p is strongly predicted to closely mimic that of adaptin-family appendages. Deletion of the appendage domain of Sec26p results in inviability in yeast, over-expression of the deletion construct is dominant negative and mutagenesis of this region identifies residues critical for function. The ArfGAP Glo3p was identified via suppression screening as a potential downstream modulator of Sec26p in a manner that is independent of the GAP activity of Glo3p but requires the presence of the COOH-terminal ISS motifs. Conclusion Together, these results indicate an essential function for the predicted βCOP appendage and suggest that both COPI appendages perform a biologically active regulatory role with a structure related to adaptin-family appendage domains.

  20. A mutation in the atrial-specific myosin light chain gene (MYL4) causes familial atrial fibrillation.

    Science.gov (United States)

    Orr, Nathan; Arnaout, Rima; Gula, Lorne J; Spears, Danna A; Leong-Sit, Peter; Li, Qiuju; Tarhuni, Wadea; Reischauer, Sven; Chauhan, Vijay S; Borkovich, Matthew; Uppal, Shaheen; Adler, Arnon; Coughlin, Shaun R; Stainier, Didier Y R; Gollob, Michael H

    2016-04-12

    Atrial fibrillation (AF), the most common arrhythmia, is a growing epidemic with substantial morbidity and economic burden. Mechanisms underlying vulnerability to AF remain poorly understood, which contributes to the current lack of highly effective therapies. Recognizing mechanistic subtypes of AF may guide an individualized approach to patient management. Here, we describe a family with a previously unreported syndrome characterized by early-onset AF (age <35 years), conduction disease and signs of a primary atrial myopathy. Phenotypic penetrance was complete in all mutation carriers, although complete disease expressivity appears to be age-dependent. We show that this syndrome is caused by a novel, heterozygous p.Glu11Lys mutation in the atrial-specific myosin light chain gene MYL4. In zebrafish, mutant MYL4 leads to disruption of sarcomeric structure, atrial enlargement and electrical abnormalities associated with human AF. These findings describe the cause of a rare subtype of AF due to a primary, atrial-specific sarcomeric defect.

  1. The Connexin40A96S mutation from a patient with atrial fibrillation causes decreased atrial conduction velocities and sustained episodes of induced atrial fibrillation in mice.

    Science.gov (United States)

    Lübkemeier, Indra; Andrié, René; Lickfett, Lars; Bosen, Felicitas; Stöckigt, Florian; Dobrowolski, Radoslaw; Draffehn, Astrid M; Fregeac, Julien; Schultze, Joachim L; Bukauskas, Feliksas F; Schrickel, Jan Wilko; Willecke, Klaus

    2013-12-01

    Atrial fibrillation (AF) is the most common type of cardiac arrhythmia and a major cause of stroke. In the mammalian heart the gap junction proteins connexin40 (Cx40) and connexin43 (Cx43) are strongly expressed in the atrial myocardium mediating effective propagation of electrical impulses. Different heterozygous mutations in the coding region for Cx40 were identified in patients with AF. We have generated transgenic Cx40A96S mice harboring one of these mutations, the loss-of-function Cx40A96S mutation, as a model for atrial fibrillation. Cx40A96S mice were characterized by immunochemical and electrophysiological analyses. Significantly reduced atrial conduction velocities and strongly prolonged episodes of atrial fibrillation were found after induction in Cx40A96S mice. Analyses of the gating properties of Cx40A96S channels in cultured HeLa cells also revealed significantly lower junctional conductance and enhanced sensitivity voltage gating of Cx40A96S in comparison to Cx40 wild-type gap junctions. This is caused by reduced open probabilities of Cx40A96S gap junction channels, while single channel conductance remained the same. Similar to the corresponding patient, heterozygous Cx40A96S mice revealed normal expression levels and localization of the Cx40 protein. We conclude that heterozygous Cx40A96S mice exhibit prolonged episodes of induced atrial fibrillation and severely reduced atrial conduction velocities similar to the corresponding human patient.

  2. [Regeneration of vertebrate appendage: an old experimental model to study stem cells in the adult].

    Science.gov (United States)

    Tawk, Marcel; Vriz, Sophie

    2003-04-01

    The application of stem cell therapy to cure degenerative diseases offers immense possibilities, but the research in this field is the subject of ethical debates raised by the question of destructive research on early human embryos. Stem cells taken in the adult constitute an alternative to human embryonic stem cells, but our knowledge on totipotent or pluripotent cells is currently insufficient. Furthermore, many questions must be solved before selection and differentiation of these cells in a given cellular type can be controlled on a routine basis. What are the molecular characteristics of an adult stem cell? What are the mechanisms involved in cell reprogramming? Which signals control stem cell replication and differentiation? Basic research activities must be carried out in order to clarify all these points. In this context, the regeneration of vertebrate appendages provides a model for this type of research. The regeneration process is defined by both the morphological and functional reconstruction of a part of a living organism, which has previously been destroyed. But why are some vertebrates able to regenerate complex structures and others apparently not? Among most vertebrates, the capacity to regenerate is limited to some tissues. It is however possible to observe the regeneration of appendages (limb, tail, fin, jaw, etc.) among several amphibians and fish. This regeneration leads to re-forming of the amputated part with a complete restoration of its shape, segmentation and function. Why is the amputation of limbs not followed by regeneration in mammals and birds: absence of stem cells, absence of recruitment signals for these cells, or absence of signal receptivity? This review constitutes a report on the current understanding of the basis of on regeneration of legs in tetrapods and of fins in fish with an emphasis in the role of the nervous system in this process.

  3. A Conserved MicroRNA Regulatory Circuit Is Differentially Controlled during Limb/Appendage Regeneration.

    Directory of Open Access Journals (Sweden)

    Benjamin L King

    Full Text Available Although regenerative capacity is evident throughout the animal kingdom, it is not equally distributed throughout evolution. For instance, complex limb/appendage regeneration is muted in mammals but enhanced in amphibians and teleosts. The defining characteristic of limb/appendage regenerative systems is the formation of a dedifferentiated tissue, termed blastema, which serves as the progenitor reservoir for regenerating tissues. In order to identify a genetic signature that accompanies blastema formation, we employ next-generation sequencing to identify shared, differentially regulated mRNAs and noncoding RNAs in three different, highly regenerative animal systems: zebrafish caudal fins, bichir pectoral fins and axolotl forelimbs.These studies identified a core group of 5 microRNAs (miRNAs that were commonly upregulated and 5 miRNAs that were commonly downregulated, as well as 4 novel tRNAs fragments with sequences conserved with humans. To understand the potential function of these miRNAs, we built a network of 1,550 commonly differentially expressed mRNAs that had functional relationships to 11 orthologous blastema-associated genes. As miR-21 was the most highly upregulated and most highly expressed miRNA in all three models, we validated the expression of known target genes, including the tumor suppressor, pdcd4, and TGFβ receptor subunit, tgfbr2 and novel putative target genes such as the anti-apoptotic factor, bcl2l13, Choline kinase alpha, chka and the regulator of G-protein signaling, rgs5.Our extensive analysis of RNA-seq transcriptome profiling studies in three regenerative animal models, that diverged in evolution ~420 million years ago, reveals a common miRNA-regulated genetic network of blastema genes. These comparative studies extend our current understanding of limb/appendage regeneration by identifying previously unassociated blastema genes and the extensive regulation by miRNAs, which could serve as a foundation for future

  4. A Conserved MicroRNA Regulatory Circuit Is Differentially Controlled during Limb/Appendage Regeneration

    Science.gov (United States)

    King, Benjamin L.; Yin, Viravuth P.

    2016-01-01

    Background Although regenerative capacity is evident throughout the animal kingdom, it is not equally distributed throughout evolution. For instance, complex limb/appendage regeneration is muted in mammals but enhanced in amphibians and teleosts. The defining characteristic of limb/appendage regenerative systems is the formation of a dedifferentiated tissue, termed blastema, which serves as the progenitor reservoir for regenerating tissues. In order to identify a genetic signature that accompanies blastema formation, we employ next-generation sequencing to identify shared, differentially regulated mRNAs and noncoding RNAs in three different, highly regenerative animal systems: zebrafish caudal fins, bichir pectoral fins and axolotl forelimbs. Results These studies identified a core group of 5 microRNAs (miRNAs) that were commonly upregulated and 5 miRNAs that were commonly downregulated, as well as 4 novel tRNAs fragments with sequences conserved with humans. To understand the potential function of these miRNAs, we built a network of 1,550 commonly differentially expressed mRNAs that had functional relationships to 11 orthologous blastema-associated genes. As miR-21 was the most highly upregulated and most highly expressed miRNA in all three models, we validated the expression of known target genes, including the tumor suppressor, pdcd4, and TGFβ receptor subunit, tgfbr2 and novel putative target genes such as the anti-apoptotic factor, bcl2l13, Choline kinase alpha, chka and the regulator of G-protein signaling, rgs5. Conclusions Our extensive analysis of RNA-seq transcriptome profiling studies in three regenerative animal models, that diverged in evolution ~420 million years ago, reveals a common miRNA-regulated genetic network of blastema genes. These comparative studies extend our current understanding of limb/appendage regeneration by identifying previously unassociated blastema genes and the extensive regulation by miRNAs, which could serve as a foundation

  5. Primary epiploic appendagitis: Clinic and radiologic imaging findings

    Directory of Open Access Journals (Sweden)

    Mustafa Koplay

    2013-01-01

    Full Text Available Introduction: Primary epiploic appendagitis (PEA is arare and self-limiting disease that can mimicking acuteapendicitis and diverticulitis because of the clinical symptoms.The present retrospective study was discussed toclinical and radiologic characteristics of PEA.Methods: We reviewed the clinical, laboratory and computedtomography (CT findings of 10 patients with PEAbetween August 2010 and December 2012.Results: Ten patients (1 female and 9 males were diagnosedwith PEA. The average age was 37.1 (15-63years. Abdominal pain was localized to the right (2 cases,20% or left (7 cases, 70% lower quadrants and generalized(1 cases, 10%. All patients were afebrile. Only twopatients showed leukocytosis. There were gastrointestinalsymptoms such as nausea (3 patients and vomiting(1patient. In all cases, a pericolic fatty mass with a hyperattenuated ring was observed on CT. All of the patientswere treated symptomatic.Conlusion: In patients have atypical symptoms and laboratoryvalues with abdominal pain (especially left lowerabdominal pain, PEA should be considered in differentialdiagnosis. For correct diagnosis and avoid unnecessarysurgery, CT must be used in diagnosis because imagingfindings characteristic of the disease.Key words: Primary epiploic appendagitis, imaging, CT

  6. Evo-Devo of amniote integuments and appendages.

    Science.gov (United States)

    Wu, Ping; Hou, Lianhai; Plikus, Maksim; Hughes, Michael; Scehnet, Jeffrey; Suksaweang, Sanong; Widelitz, Randall; Jiang, Ting-Xin; Chuong, Cheng-Ming

    2004-01-01

    Integuments form the boundary between an organism and the environment. The evolution of novel developmental mechanisms in integuments and appendages allows animals to live in diverse ecological environments. Here we focus on amniotes. The major achievement for reptile skin is an adaptation to the land with the formation of a successful barrier. The stratum corneum enables this barrier to prevent water loss from the skin and allowed amphibian / reptile ancestors to go onto the land. Overlapping scales and production of beta-keratins provide strong protection. Epidermal invagination led to the formation of avian feather and mammalian hair follicles in the dermis. Both adopted a proximal - distal growth mode which maintains endothermy. Feathers form hierarchical branches which produce the vane that makes flight possible. Recent discoveries of feathered dinosaurs in China inspire new thinking on the origin of feathers. In the laboratory, epithelial - mesenchymal recombinations and molecular mis-expressions were carried out to test the plasticity of epithelial organ formation. We review the work on the transformation of scales into feathers, conversion between barbs and rachis and the production of "chicken teeth". In mammals, tilting the balance of the BMP pathway in K14 noggin transgenic mice alters the number, size and phenotypes of different ectodermal organs, making investigators rethink the distinction between morpho-regulation and pathological changes. Models on the evolution of feathers and hairs from reptile integuments are discussed. A hypothetical Evo-Devo space where diverse integument appendages can be placed according to complex phenotypes and novel developmental mechanisms is presented.

  7. High Accuracy Attitude Control System Design for Satellite with Flexible Appendages

    Directory of Open Access Journals (Sweden)

    Wenya Zhou

    2014-01-01

    Full Text Available In order to realize the high accuracy attitude control of satellite with flexible appendages, attitude control system consisting of the controller and structural filter was designed. When the low order vibration frequency of flexible appendages is approximating the bandwidth of attitude control system, the vibration signal will enter the control system through measurement device to bring impact on the accuracy or even the stability. In order to reduce the impact of vibration of appendages on the attitude control system, the structural filter is designed in terms of rejecting the vibration of flexible appendages. Considering the potential problem of in-orbit frequency variation of the flexible appendages, the design method for the adaptive notch filter is proposed based on the in-orbit identification technology. Finally, the simulation results are given to demonstrate the feasibility and effectiveness of the proposed design techniques.

  8. Strangulation Caused by a Small Bowel Epiploic Appendage: Report of a Case

    Directory of Open Access Journals (Sweden)

    Hiroshi Nemoto

    2008-07-01

    Full Text Available While many recent cases of colonic epiploic appendage causing acute abdomen have been reported, such appendages of the small bowel are extremely rare. We present a 59-year-old woman in whom a small bowel epiploic appendage caused volvulus. She presented with abdominal pain and vomiting in the absence of previous abdominal operations. A diagnosis of small bowel obstruction from strangulation was made. Laparotomy disclosed bloody peritoneal fluid and a closed loop of strangulated small intestine. An adherent band composed of an epiploic appendage and intestine had completely encircled a loop of jejunum, leading to obstruction. This band was released, and approximately 80 cm of gangrenous bowel was resected. Four epiploic appendages 5–6 cm in length were attached to the ileum at the mesenteric border, beginning at a point 70 cm proximal to the terminal ileum.

  9. Integrin β1 Participates in Atrial Remodeling in Rapid Atrial Pacing Induced Canine Atrial Fibrillation Model

    Institute of Scientific and Technical Information of China (English)

    Zhang wei; Yang guirong; Zheng zhaotong; Wang sujia; Zhang yun

    2004-01-01

    @@ Objective Integrin β1 regulates cell to cell and cell to extracellualr matrix interaction in heart. however, its pathop hysiological role in atrial fibrillation is unclear. The purpose of t his study was to determine whether atrial structural remodeling during atrial fibrillation is associated with altered integrinβ1.

  10. Coefficient of Variation of P-Wave Duration Is a Novel Atrial Heterogeneity Index to Predict Recurrence of Atrial Fibrillation After Catheter Ablation.

    Science.gov (United States)

    Nakatani, Yosuke; Sakamoto, Tamotsu; Mizumaki, Koichi; Nishida, Kunihiro; Kataoka, Naoya; Tsujino, Yasushi; Yamaguchi, Yoshiaki; Inoue, Hiroshi

    2016-05-01

    Atrial conduction heterogeneity is associated with progression of atrial fibrillation (AF). However, the relationship between P-wave parameters representing atrial conduction heterogeneity and AF recurrence after catheter ablation (ABL) is still unclear. Subjects of the study were 126 consecutive patients with AF (78 paroxysmal and 48 persistent) who had received ABL. Coefficient of variation of P-wave duration (CV-PWD) was determined with all 12 surface electrocardiographic leads as an index of atrial conduction heterogeneity. Rates of freedom from AF recurrence were 78% and 77% in patients with paroxysmal and persistent AF, respectively, over a 12-month follow-up. CV-PWD measured before ABL was smaller in AF-free patients compared with AF-recurrent patients (0.089 ± 0.019 vs. 0.129 ± 0.042, P < 0.001). CV-PWD significantly decreased after ABL in AF-free patients, but did not change in AF-recurrent patients. CV-PWD after ABL was also smaller in AF-free patients compared with AF-recurrent patients (0.087 ± 0.025 vs. 0.133 ± 0.035, P < 0.001). In receiver operating curve analysis, CV-PWD before and after ABL achieved area under the curve of 0.829 and 0.854, respectively, for the ability to predict AF recurrence. CV-PWD correlated positively with left atrial (LA) diameter and negatively with LA appendage flow velocity. CV-PWD is a useful index to predict AF recurrence after ABL for both patients with paroxysmal and persistent AF. ABL may suppress AF by decreasing atrial conduction heterogeneity. © 2016 Wiley Periodicals, Inc.

  11. Stroke prevention in atrial fibrillation

    DEFF Research Database (Denmark)

    Freedman, Ben; Potpara, Tatjana S; Lip, Gregory Y H

    2016-01-01

    Atrial fibrillation is found in a third of all ischaemic strokes, even more after post-stroke atrial fibrillation monitoring. Data from stroke registries show that both unknown and untreated or under treated atrial fibrillation is responsible for most of these strokes, which are often fatal...... or debilitating. Most could be prevented if efforts were directed towards detection of atrial fibrillation before stroke occurs, through screening or case finding, and treatment of all patients with atrial fibrillation at increased risk of stroke with well-controlled vitamin K antagonists or non-vitamin K...

  12. Ferrofluid Appendages: Fluid Fins, a Numerical Investigation on the Feasibility of using Fluids as Shapeable Propulsive Appendages

    Directory of Open Access Journals (Sweden)

    M. A. Feizi Chekab

    2017-01-01

    Full Text Available The present study focuses on the feasibility of using fluids, and in particular magnetic fluids, as “Fluid Structures” in designing external appendages for the submerged bodies and propulsive fins as a practical example. After reviewing the literature of the mathematical simulation of magnetic fluids and their applications, the concept of “Fluid Structures” and “Fluid Fins” are briefly introduced. The validation of the numerical solver against analytical solutions is presented and acceptable error of 1.21% up to 2.29% is estimated. Subsequently, the initial shaping of the ferrofluid as an external fluid fin, using three combinations of internal magnetic actuators, is presented which makes the way to the oscillating motion of the obtained fin, by producing a periodically changing magnetic field. It is demonstrated that the shape of the fluid fin is almost the replica of the magnetic field. On the other hand, it is illustrated that a fluid fin with a size under 0.005 m on a circular submerged body of 1cm diameter could produce 0.0158 N force which is a high thrust force relative to the size of the body and the fin. Based on the obtained results, one may conclude that, when a “Fluid Fin” is capable of producing this amount of thrust, other fluid appendages could be scientifically contemplated and practically designed.

  13. Atrial natriuretic peptide in patients with heart failure and chronic atrial fibrillation : Role of duration of at atrial fibrillation

    NARCIS (Netherlands)

    Van Den Berg, MP; Crijns, HJGM; Van Veldhuisen, DJ; Van Gelder, IC; De Kam, PJ; Lie, KI

    1998-01-01

    The purpose of this study was to analyze the determinants of atrial natriuretic peptide level in patients with congestive heart failure and atrial fibrillation. In particular, the duration of atrial fibrillation was analyzed because atrial fibrillation per se might have a specific effect on atrial n

  14. Changes in human atrial myocyte dimension among different ages%不同年龄人心房肌细胞的形态观察

    Institute of Scientific and Technical Information of China (English)

    孙秀梅; 胡小琴; 苏俊武; 潘世伟; 刘迎龙

    2001-01-01

    AIM: To observe the changes in right atrial myocyte dimensionswith myocardial development. METHODS: Cell length, width, length/width and cross-sectional area were measured in right atrial myocytes isolated from 12 weaning [ages 0.4-5 years, (1.8±1.3) years, n=103 cells], 10 young [6-11 years, (9.3±1.8) years, n=104 cells], 13 adult [30-56 years, (43.7±11.5) years, n=110 cells] human hearts. RESULTS: Cell length, width, length/width and cross-sectional area, at weanling group were (70.2±1.3) μm, (8.0±0.2) μm, (9.0±0.2) and (50.9±2.6) μm2, respectively, at young group were (93.5±1.6) μm, (11.7±0.3) μm, 8.1±0.2, (109.7±5.8) μm2, and (100.9±2.2) μm, (12.1±0.3) μm, 8.5±0.2, (119.0±5.5) μm2 for adult group. Clearly, young myocyte lenght, width, cross-sectional area were greater than that of myocytes at weanling group(P<0.01) but adult myocytes length/width and cross-sectional area increase slightly compared with young group. The length/width ratio has no significant change through myocyte maturity, which is between 8-9. CONCLUSIONS: Our data suggest that myocyte dimensions expect length/width ratio have increased progressively with maturity, the length/width ratio is preserved in atrial myocyte during the period of normal myocyte growth from weanling to adulthood, and these changes in myocyte dimensions are similar with ventricular myocytes changes from other mammalian species.%的:观察不同年龄人心房肌细胞的形态变化。方法:取右心房组织块进行酶解,得到单个细胞。分别观察小儿组(12例0.4-5岁,平均1.8岁±1.3岁,n=103个细胞)、儿童组(10例6-11岁,平均9.3岁±1.8岁,n=104)、成年组(13例30-56岁,平均43.7岁±11.5岁,n=110)病人心房肌细胞的长、宽(直径)、长/宽比和细胞横截面积(±s)。结果:细胞长(μm)小儿组为70.2±1.3,儿童组为93.5±1.6,成年组为100.8±2.2,细胞宽(μm)分别为8.0±0.2、11.7±0.3、12.0±0.3

  15. Comparison of Approaches for Stroke Prophylaxis in Patients with Non-Valvular Atrial Fibrillation: Network Meta-Analyses of Randomized Controlled Trials

    Science.gov (United States)

    Patel, Nirav; Hashim, Taimoor; Godara, Hemant; Ather, Sameer; Arora, Garima; Pasala, Tilak; Whitfield, Thomas T.; McGiffin, David C.; Ahmed, Mustafa I.; Lloyd, Steven G.; Limdi, Nita A.

    2016-01-01

    Background Multiple novel oral anticoagulants and left atrial appendage closure devices (WATCHMAN) have been tested against dose-adjusted vitamin K antagonists in randomized controlled trials for stroke prophylaxis in non-valvular atrial fibrillation. No direct comparisons of these strategies are available from randomized controlled trials. We conducted the current analyses by combining efficacy and safety characteristics of all FDA approved stroke prophylaxis treatment strategies for patients with non-valvular atrial fibrillation. Materials and Methods We searched SCOPUS from 1945 till October 2015 for randomized controlled trials comparing these strategies and reporting efficacy and safety outcomes. Six randomized controlled trials were identified and included in the final analyses and review. We followed PRISMA guidelines for network meta-analyses while reporting the current analyses. We collected data on ischemic stroke, major bleeding, and the composite primary safety endpoint as defined by various randomized controlled trials. Network meta-analyses were conducted using consistency and inconsistency models for efficacy and safety outcomes. Surface under the cumulative ranking curve were then utilized to cluster rank these treatments for safety and efficacy. Results Six randomized controlled trials with 59,627 patients comparing six treatment strategies were eligible for the analyses. All prophylaxis strategies had comparable rates of ischemic stroke. Apixaban was associated with the least number of primary safety endpoint events as compared with all other treatments. In the cluster analyses assessing safety and efficacy, apixaban, edoxaban and dabigatran ranked best followed by vitamin K antagonists and rivaroxaban, whereas the WATCHMAN left atrial appendage closure device ranked last. Conclusions Dose-adjusted vitamin K antagonists, novel oral anticoagulants, and the WATCHMAN left atrial appendage closure devices are equally efficacious for ischemic stroke

  16. Modulation of atrial fibrillation

    NARCIS (Netherlands)

    Geuzebroek, G.S.C.

    2013-01-01

    In this thesis we investigate the results of various surgical procedures for atrial fibrillation which have been performed in the last 2 decades in the Sint Antonius Hospital, Nieuwegein, The Netherlands. In the 1990s the classical Maze III procedure was the main surgical technique for drug-refracto

  17. Lesson Five Atrial fibrillation

    Institute of Scientific and Technical Information of China (English)

    鲁端; 吴文烈

    2003-01-01

    @@ Atrial fibrillation(AF) may occur in paroxysmaland persistent forms. It may be seen in normal subjects,particularly during emotional stress or follow-ing surgery,exercise, or acute alcoholic intoxication.It also may occur in patients with heart or lungdisease who develop acute hypoxia, hypercapnia,ormetabolic or hemodynamic derangements.

  18. Protective effect of. cap alpha. -human atrial natriuretic polypeptide (. cap alpha. -hANP) on chemical-induced pulmonary edema

    Energy Technology Data Exchange (ETDEWEB)

    Imamura, T.; Ohnuma, N.; Iwasa, F.; Furuya, M.; Hayashi, Y.; Inomata, N.; Ishihara, T.; Noguchi, T.

    1988-01-01

    It has been established that ..cap alpha..-hANP, the newly discovered peptide extracted from human cardiac atria, has potent natriuretic and hypotensive actions. The authors present investigation is the first to demonstrate that ..cap alpha..-hANP is capable of protecting against pulmonary edema caused by various chemicals, using isolated perfused guinea pig lung system. Lungs were perfused via pulmonary artery with Krebs-Ringer bicarbonate buffer at 5.0 ml/min, and wet weight of lungs and perfusion pressure of pulmonary artery (Pa) were monitored. Bolus injection of Triton-X or CHAPS into cannulated pulmonary artery produced enema as indicated by a massive increase in wet weight and a slight increase in Pa. Constant infusion of ..cap alpha..-hANP through pulmonary artery at 200 ng/ml was effective in causing decrease in wet weight of lung. Perfusion of lung with paraquat or PGF/sub 2..cap alpha..'/, and repeated bolus injection of arachidonic acid or PGE/sub 2/ caused elevation in both wet weight of lung and Pa.

  19. Medical image of the week: bilateral atrial appendange thrombi

    Directory of Open Access Journals (Sweden)

    Ateeli H

    2015-01-01

    Full Text Available No abstract available. Article truncated at 150 words. A 63-year-old man with a past history significant for hypertension, low back pain and polysubstance abuse (tobacco and marijuana presented with shortness of breath and hemoptysis for the last 8 days prior to admission. His initial exam showed elevated jugular venous pressure and bilateral basal crackles with reduced air entry on the right lower lung zone. The patient was found to be in atrial fibrillation with a rapid ventricular response. His initial chest X-ray showed a moderate right-sided pleural effusion. Immediate bedside echo was concerning for bilateral ventricular dysfunction with concerns of right-sided heart pressure and volume overload. A chest CT angiogram was obtained and showed acute lower lobe pulmonary embolism, with possible distal infarct, moderate right sided pleural effusion, and filling defects in both atrial appendages concerning for thrombi (Figure 1, Panels A & B. The patient was started on therapeutic anticoagulation and underwent therapeutic thoracentesis, gentle diuresis, and ...

  20. Current problems concerning parasitology and mycology with regard to diseases of the skin and its appendages.

    Science.gov (United States)

    Błaszkowska, Joanna; Wójcik, Anna

    2012-01-01

    Current issues concerning Parasitology and Mycology with regard to diseases of the skin and its appendages are presented. Aspects of diagnostics, clinical picture and therapy of skin and nail mycoses, as well as difficulties in the diagnosis and treatment of both native parasitoses (toxoplasmosis) and imported human tropical parasitoses (malaria, filariosis) have been emphasised. The clinical importance of environmental mould fungi in nosocomial infections and fungal meningitis, as well as selected properties of fungi isolated from patients with head and neck neoplasms treated by radiotherapy are discussed. Other mycological topics include the characteristics of newly-synthesized thiosemicarbazides and thiadiazoles as potential drugs against toxoplasmosis and their biological activity against Toxoplasma gondii tachyzoites, selected molecular mechanisms of resistance to azoles, Candida albicans strains and a new tool (barcoding DNA) for describing the biodiversity of potential allergenic molds. The importance of environmental factors in pathogenesis of mycoses and parasitoses is noted. The characteristics of pathogenic fungi isolated from natural ponds in Bialystok and potentially pathogenic yeast-like fungi isolated from children's recreation areas in Lodz are presented. The ongoing problem of anthropozoonoses is considered, as are the roles of stray cats and dogs in contaminating soil with the developing forms of intestinal parasites. The characteristics of the human microbiome, including population composition, activity and their importance in normal human physiology, are presented, as are the major goals of the Human Microbiome Project initiated by National Institutes of Health (NIH).

  1. Passive control of a falling sphere by elliptic-shaped appendages

    Science.gov (United States)

    Lācis, Uǧis; Olivieri, Stefano; Mazzino, Andrea; Bagheri, Shervin

    2017-03-01

    The majority of investigations characterizing the motion of single or multiple particles in fluid flows consider canonical body shapes, such as spheres, cylinders, discs, etc. However, protrusions on bodies—either surface imperfections or appendages that serve a function—are ubiquitous in both nature and applications. In this work, we characterize how the dynamics of a sphere with an axis-symmetric wake is modified in the presence of thin three-dimensional elliptic-shaped protrusions. By investigating a wide range of three-dimensional appendages with different aspect ratios and lengths, we clearly show that the sphere with an appendage may robustly undergo an inverted-pendulum-like (IPL) instability. This means that the position of the appendage placed behind the sphere and aligned with the free-stream direction is unstable, similar to how an inverted pendulum is unstable under gravity. Due to this instability, nontrivial forces are generated on the body, leading to turn and drift, if the body is free to fall under gravity. Moreover, we identify the aspect ratio and length of the appendage that induces the largest side force on the sphere, and therefore also the largest drift for a freely falling body. Finally, we explain the physical mechanisms behind these observations in the context of the IPL instability, i.e., the balance between surface area of the appendage exposed to reversed flow in the wake and the surface area of the appendage exposed to fast free-stream flow.

  2. Characterization of a novel Bacillus thuringiensis phenotype possessing multiple appendages attached to a parasporal body.

    Science.gov (United States)

    Ventura-Suárez, Antonio; Cruz-Camarillo, Ramón; Rampersad, Joanne; Ammons, David R; López-Villegas, Edgar O; Ibarra, Jorge E; Rojas-Avelizapa, Luz I

    2011-01-01

    Bacillus thuringiensis is a bacterium best known for its production of crystal-like bodies comprised of one or more Cry-proteins, which can be toxic to insects, nematodes or cancer cells. Although strains of B. thuringiensis have occasionally been observed with filamentous appendages attached to their spores, appendages in association with their parasporal bodies are extremely rare. Herein we report the characterization of Bt1-88, a bacterial strain isolated from the Caribbean that produces a spore-crystal complex containing six long appendages, each comprised of numerous thinner filaments approximately 10 nm in diameter and 2.5 μm in length. Each of the multi-filament appendages was attached to a single, small parasporal body located at one end of the bacterial spore. Biochemical tests, 16S rDNA gene sequencing, and the identification of two Cry proteins by partial protein sequencing (putatively Cry1A and Cry2A), unambiguously identified Bt1-88 as a strain of B. thuringiensis. Bt1-88 represents the second reported strain of B. thuringiensis possessing a parasporal body/appendage phenotype characterized by one or more long appendages, comprised of numerous filaments in association with a parasporal body. This finding suggests that Bt1-88 is a member of a new phenotypic class of B. thuringiensis, in which the parasporal body may perform a novel structural role through its association with multi-filament appendages.

  3. Right atrial mural thrombi: An autopsy study of an under-diagnosed complication at an unusual site

    Directory of Open Access Journals (Sweden)

    P Vaideeswar

    2017-01-01

    Full Text Available Background: Right atrial mural thrombi (RAMT are often seen in association with cardiac diseases or foreign bodies. Unusual locations at the flutter isthmus and the atrial appendage prompted us to evaluate our 2-year autopsy data on such thrombi. Materials and Methods: In the 2-year retrospective autopsy, the clinical and autopsy records of patients with RAMT were reviewed, with particular reference to the presence of central venous catheter (CVC, its site of insertion, its type, material and size, its duration of placement, and the drugs infused through the catheter. Results: Of the 940 autopsies performed in 2 years, RAMT was seen in 24 hearts and was related to an insertion of a CVC in 23 patients (95.8%. The risk and/or associated factors for this complication were tunneled and polyethylene catheters, Intensive Care Unit admission, infused drugs, underlying cardiac diseases, and pregnancy. A noteworthy feature was the location of the thrombi in the flutter isthmus in 16 hearts (66.7% and atrial appendage in another six hearts. Localized endocarditis/myocarditis and pulmonary thromboembolism were observed in six and four patients, respectively.Conclusions: This autopsy study, which has a high incidence of catheter-related RAMT, does not reflect the true incidence but reiterates the importance of guided insertion of central venous and prompt recognition of thrombus formation.

  4. Complex fractionated electrogram distribution and temporal stability in patients undergoing atrial fibrillation ablation.

    Science.gov (United States)

    Roux, Jean-François; Gojraty, Sattar; Bala, Rupa; Liu, Christopher F; Hutchinson, Mathew D; Dixit, Sanjay; Callans, David J; Marchlinski, Francis; Gerstenfeld, Edward P

    2008-08-01

    Targeting of complex fractionated electrograms (CFEs) has been described as an approach for catheter ablation of atrial fibrillation (AF); however, the distribution and temporal stability of CFE regions remain poorly defined. In patients with persistent AF referred for ablation, we performed two consecutive left atrial (LA) CFE maps prior to AF ablation. Bipolar electrograms were acquired during AF, and the mean AF cycle length and electrogram voltage were automatically determined at each point. Sites with mean CL CFE positive. The two maps were then compared qualitatively and quantitatively. A total of 15 patients (93% male, age 56.1 +/- 9.0 years) undergoing AF ablation were studied. The two maps were separated in time by 31 +/- 10 minutes. There was no significant difference in the number of CFE-positive regions (12.3 +/- 5.2 vs 11.3 +/- 4.7; P = 0.06) between the maps. While CFEs were widely distributed within the LA, the PV/left atrial junction (73%) and left atrial appendage (77%) were most often CFE positive. The presence of CFEs at each region was concordant 78% of the time. There was a significant correlation between the two maps (r = 0.35 +/- 0.21, range 0.1-0.84; P CFE regions are found in the vicinity of the PVs. There is a significant correlation between two CFE maps constructed 31 minutes apart, with 78% concordance of CFE sites.

  5. Acute Appendagitis Presenting with Features of Appendicitis: Value of Abdominal CT Evaluation

    Directory of Open Access Journals (Sweden)

    Sukhpreet Dubb

    2008-05-01

    Full Text Available We report a case of acute appendagitis in a patient who presented initially with typical features of acute appendicitis. The diagnosis of acute appendagitis was made on pathognomonic signs on computed tomography (CT scan. Abdominal pain is a common surgical emergency. CT is not always done if there are clear features of acute appendicitis. The rare but important differential diagnosis of acute appendagitis must be borne in mind when dealing with patients with suspected acute appendicitis. A CT scan of the abdomen may avoid unnecessary surgery in these patients.

  6. HYPERTHYROIDISM AND ATRIAL FIBRILLATION

    Directory of Open Access Journals (Sweden)

    I. M. Marusenko

    2017-01-01

    Full Text Available Review on a problem of the development of atrial fibrillation in patients with thyrotoxicosis is presented. Thyrotoxicosis is one of the most frequent endocrine diseases, conceding only to a diabetes mellitus. The most frequent reasons of hyperthyroidism are Graves’ disease and functional thyroid autonomy. The authors give an analysis of data on the cardiac effects of thyrotoxicosis, features of heart remodeling under the influence of thyroid hyperfunction, prevalence of atrial fibrillation in thyrotoxicosis, depending on age, as well as the possibility of restoring sinus rhythm in the combination of these diseases. Particular attention is paid to the effect on the heart of subclinical thyrotoxicosis, which is defined as a dysfunction of the thyroid gland, characterized by low serum concentration of thyrotropin, normal values of free thyroxine and free triiodothyronine. Subclinical hyperthyroidism is also capable of causing heart remodeling and diastolic dysfunction.Prevalence of thyrotoxicosis in elderly people is higher in areas of iodine deficiency; it is relevant for our country due to the large territory of iodine deficiency. In elderly patients, the cardiac effects of thyrotoxicosis prevail in the clinical picture, that makes it difficult to diagnose endocrine disorders, and correction of thyrotoxicosis is critically important for the successful control of the heart rhythm. The article also discusses the problem of thyrotoxic cardiomyopathy, caused by the toxic effect of excess thyroid hormones: features of this heart disorder, factors affecting its formation, clinical significance and contribution to the development of rhythm disturbances. The greatest significance is the development of atrial fibrillation as a result of thyrotox-icosis in older patients who already have various cardiovascular diseases.Atrial fibrillation is the most frequent heart rhythm disorder in thyrotoxicosis. The main cause of arrhythmia in hyperthyroidism is the

  7. Hepatocyte growth factor and basic fibroblast growth factor regulate atrial fibrosis in patients with atrial fibrillation and rheumatic heart disease via the mitogen-activated protein kinase signaling pathway.

    Science.gov (United States)

    Li, Mingjiang; Yi, Xin; Ma, Lele; Zhou, Yanli

    2013-11-01

    The aim of this study was to investigate the interrelation between basic fibroblast growth factor (bFGF), hepatocyte growth factor (HGF) and atrial fibrosis in patients with atrial fibrillation (AF) and rheumatic heart disease (RHD), and to explore the possible molecular mechanisms underlying this interrelation. Twenty patients with RHD who were scheduled for valve replacement were divided into two groups, comprising 10 cases with AF and 10 cases with sinus rhythm (SR). Clinical data were collected and a small sample of aseptic left atrial appendage was collected by the surgeon. Hematoxylin and eosin (H&E) and Masson's trichrome-stained sections were used to evaluate the cross-sectional area and level of fibrosis, respectively. The expression levels of bFGF and HGF were assessed using immunohistochemistry. The phosphorylation levels of mitogen-activated protein kinase/extracellular signal-regulated kinase 1/2 (MEK1/2), c-Jun N-terminal kinase 1/2 (JNK1/2), extracellular signal-regulated kinase 1/2 (ERK1/2) and p38 in atrial tissue were measured using western blotting. Compared with the SR group, myocardial cell diameter was significantly expanded and there was increased collagen deposition in the AF group (Pfibrosis, while HGF may function in an opposite manner in patients with AF and RHD. The mitogen-activated protein kinase (MAPK) signaling pathway may be the molecular basis for these roles in atrial fibrosis.

  8. Multimodality imaging for patient evaluation and guidance of catheter ablation for atrial fibrillation - current status and future perspective.

    Science.gov (United States)

    Bhagirath, P; van der Graaf, A W M; Karim, R; van Driel, V J H M; Ramanna, H; Rhode, K S; de Groot, N M S; Götte, M J W

    2014-08-20

    Left atrial catheter ablation is an established non-pharmacological therapy for the treatment of atrial fibrillation. The importance of a noninvasive multimodality imaging approach is emphasized by the current guidelines for the various phases of the ablation work-up e.g. patient identification, therapy guidance and procedural evaluation. Advances in the capabilities of imaging modalities and the increasing cost of healthcare warrant a review of the multimodality approach. This review discusses the application of cardiac imaging for pulmonary vein and left atrial ablation divided into stages: pre-procedural stage (assessment of left atrial dimensions, left atrial appendage thrombus and pulmonary vein anatomy), peri-procedural stage (integration of anatomical and electrical information) and post-procedural stage (evaluation of efficacy by assessment of tissue properties). Each section is dedicated to one of the subtopics of a stage, allowing a thorough comparison to be made between the strengths and weaknesses of the different imaging modalities and the identification of one that exhibits the potential for a single technique approach.

  9. Atrial fibrillation in the elderly

    Institute of Scientific and Technical Information of China (English)

    Roberto A.Franken; Ronaldo F.Rosa; Silvio CM Santos

    2012-01-01

    This review discusses atrial fibrillation according to the guidelines of Brazilian Society of Cardiac Arrhythmias and the Brazilian Cardiogeriatrics Guidelines. We stress the thromboembolic burden of atrial fibrillation and discuss how to prevent it as well as the best way to conduct cases of atrial fibrillatios in the elderly, reverting the arrhythmia to sinus rhythm, or the option of heart rate control. The new methods to treat atrial fibrillation, such as radiofrequency ablation, new oral direct thrombin inhibitors and Xa factor inhibitors, as well as new antiarrhythmic drugs, are depicted.

  10. Hypertension and Atrial Fibrillation

    DEFF Research Database (Denmark)

    Dzeshka, Mikhail S.; Shahid, Farhan; Shantsila, Alena

    2017-01-01

    Atrial fibrillation (AF) is the most prevalent sustained arrhythmia found in clinical practice. AF rarely exists as a single entity but rather as part of a diverse clinical spectrum of cardiovascular diseases, related to structural and electrical remodeling within the left atrium, leading to AF o...... of complications as the first clinical manifestation of the disease. Antithrombotic prevention in AF combined with strict blood pressure control is of primary importance, since stroke risk and bleeding risk are both greater with underlying hypertension....... onset, perpetuation, and progression. Due to the high overall prevalence within the AF population arterial hypertension plays a significant role in the pathogenesis of AF and its complications. Fibroblast proliferation, apoptosis of cardiomyocytes, gap junction remodeling, accumulation of collagen both...... in atrial and ventricular myocardium all accompany ageing-related structural remodeling with impact on electrical activity. The presence of hypertension also stimulates oxidative stress, systemic inflammation, rennin-angiotensin-aldosterone and sympathetic activation, which further drives the remodeling...

  11. Electrophysiologic and Clinical Consequences of Left Atrial Anterior Wall Linear Ablation in Patients With Persistent Atrial Fibrillation.

    Science.gov (United States)

    Zhang, Jinlin; Tang, Cheng; Zhang, Yonghua; Su, X I

    2015-05-20

    As an alternative to the mitral isthmus line (MIL), the left atrial anterior wall line (LAAWL) is effective for the treatment of perimitral flutter. This study evaluated the electrophysiologic and clinical outcomes of LAAWL versus MIL in patients with persistent atrial fibrillation (AF). Two hundred patients with persistent AF were evenly randomized to the LAAWL and MIL groups. After confirming bidirectional block of the line, left atrial appendage (LAA) activation time and LA propagation pattern were assessed during sinus rhythm (SR). Transthoracic and transesophageal echocardiography (TTE and TEE) were performed at 12 months after ablation in patients who remained in stable SR. In the 74 patients with LAAWL conduction block relative to the 79 with MIL conduction block, LA propagation contour was markedly changed with delayed LAA potential (longer P-wave onset-to-LAA potential interval: 151.7 ± 19.5 vs. 67.8 ± 18.3 milliseconds, P wave was delayed in the LAAWL group compared with the MIL group; spontaneous echo contrast (SEC) detected in the LAAWL group was significantly higher than that in the MIL group (15.8% vs. 1.6%, p = 0.0004). During a mean follow-up period of 31.8 ± 9.4 (22-57) months, there were 5 cases of stroke in the LAAWL group, which was significantly different from the MIL group (5% vs. 0%, P = 0.047). Complete linear lesions transecting the anterior LA were associated with a significant change in the SR propagation pattern with late activation of LAA. This might result in an increased risk of long-term thrombo-embolism events. © 2015 Wiley Periodicals, Inc.

  12. Prevalence of right atrial non-pulmonary vein triggers in atrial fibrillation patients treated with thyroid hormone replacement therapy.

    Science.gov (United States)

    Kim, Ki-Hun; Mohanty, Sanghamitra; Mohanty, Prasant; Trivedi, Chintan; Morris, Eli Hamilton; Santangeli, Pasquale; Bai, Rong; Al-Ahmad, Amin; Burkhardt, John David; Gallinghouse, Joseph G; Horton, Rodney; Sanchez, Javier E; Bailey, Shane; Hranitzky, Patrick M; Zagrodzky, Jason; Kim, Soo G; Di Biase, Luigi; Natale, Andrea

    2017-08-01

    Thyroid hormone (TH) is known to enhance arrhythmogenicity, and high-normal thyroid function is related with an increased recurrence of atrial fibrillation (AF) after catheter ablation. However, the impact of thyroid hormone replacement (THR) on AF ablation is not well known. This study evaluated 1163 consecutive paroxysmal AF patients [160 (14%) on THR and 1003 (86%) without THR] undergoing their first catheter ablation. A total of 146 patients on THR and 146 controls were generated by propensity matching, based on calculated risk factor scores, using a logistic model (age, sex, body mass index, and left atrium size). The presence of non-pulmonary vein (PV) triggers was disclosed by a high-dose isoproterenol challenge (up to 30 μg/min) after PV isolation. Clinical characteristics were not different between the groups. When compared to the control, non-PV triggers were significantly greater in the THR patients [112 (77%) vs. 47 (32%), P right atrium (95 vs. 56%, P sources of non-PV triggers were the interatrial septum (25 vs. 11%, P = 0.002), coronary sinus (70 vs. 52%, P = 0.01), left atrial appendage (47 vs. 34%, P = 0.03), crista terminalis/superior vena cava (11 vs. 8%, P = 0.43), and mitral valve annulus (7 vs. 5%, P = 0.45) (THR vs. control), respectively. After mean follow-up of 14.7 ± 5.2 months, success rate was lower in patients on THR therapy [94 (64.4%)] compared to patients not receiving THR therapy [110 (75.3%), log-rank test value = 0.04]. Right atrial non-PV triggers were more prevalent in AF patients treated with THR. Elimination of non-PV triggers provided better arrhythmia-free survival in the non-THR group.

  13. Canonical Wnt signalling regulates epithelial patterning by modulating levels of laminins in zebrafish appendages.

    Science.gov (United States)

    Nagendran, Monica; Arora, Prateek; Gori, Payal; Mulay, Aditya; Ray, Shinjini; Jacob, Tressa; Sonawane, Mahendra

    2015-01-15

    The patterning and morphogenesis of body appendages - such as limbs and fins - is orchestrated by the activities of several developmental pathways. Wnt signalling is essential for the induction of limbs. However, it is unclear whether a canonical Wnt signalling gradient exists and regulates the patterning of epithelium in vertebrate appendages. Using an evolutionarily old appendage - the median fin in zebrafish - as a model, we show that the fin epithelium exhibits graded changes in cellular morphology along the proximo-distal axis. This epithelial pattern is strictly correlated with the gradient of canonical Wnt signalling activity. By combining genetic analyses with cellular imaging, we show that canonical Wnt signalling regulates epithelial cell morphology by modulating the levels of laminins, which are extracellular matrix components. We have unravelled a hitherto unknown mechanism involved in epithelial patterning, which is also conserved in the pectoral fins - evolutionarily recent appendages that are homologous to tetrapod limbs.

  14. Inhibitory effects of hesperetin on Kv1.5 potassium channels stably expressed in HEK 293 cells and ultra-rapid delayed rectifier K(+) current in human atrial myocytes.

    Science.gov (United States)

    Wang, Huan; Wang, Hong-Fei; Wang, Chen; Chen, Yu-Fang; Ma, Rong; Xiang, Ji-Zhou; Du, Xin-Ling; Tang, Qiang

    2016-10-15

    In the present study, the inhibitory effects of hesperetin (HSP) on human cardiac Kv1.5 channels expressed in HEK 293 cells and the ultra-rapid delayed rectifier K(+) current (Ikur) in human atrial myocytes were examined by using the whole-cell configuration of the patch-clamp techniques. We found that hesperetin rapidly and reversibly suppressed human Kv1.5 current in a concentration dependent manner with a half-maximal inhibition (IC50) of 23.15 μΜ with a Hill coefficient of 0.89. The current was maximally diminished about 71.36% at a concentration of 300μM hesperetin. Hesperetin significantly positive shifted the steady-state activation curve of Kv1.5, while negative shifted the steady-state inactivation curve. Hesperetin also accelerated the inactivation and markedly slowed the recovery from the inactivation of Kv1.5 currents. Block of Kv1.5 currents by hesperetin was in a frequency dependent manner. However, inclusion of 30μM hesperetin in pipette solution produced no effect on Kv1.5 channel current, while the current were remarkable and reversibly inhibited by extracellular application of 30μM hesperetin. We also found that hesperetin potently and reversibly inhibited the ultra-repaid delayed K(+) current (Ikur) in human atrial myocytes, which is in consistent with the effects of hesperetin on Kv1.5 currents in HEK 293 cells. In conclusion, hesperetin is a potent inhibitor of Ikur (which is encoded by Kv1.5), with blockade probably due to blocking of both open state and inactivated state channels from outside of the cell.

  15. Refractoriness in human atria

    DEFF Research Database (Denmark)

    Skibsbye, Lasse; Jespersen, Thomas; Christ, Torsten

    2016-01-01

    drugs. Cardiomyocyte excitability depends on availability of sodium channels, which involves both time- and voltage-dependent recovery from inactivation. This study therefore aims to characterise how sodium channel inactivation affects refractoriness in human atria. METHODS AND RESULTS: Steady......-state activation and inactivation parameters of sodium channels measured in vitro in isolated human atrial cardiomyocytes were used to parameterise a mathematical human atrial cell model. Action potential data were acquired from human atrial trabeculae of patients in either sinus rhythm or chronic atrial...... in pharmacological management of chronic atrial fibrillation....

  16. Appendage modal coordinate truncation criteria in hybrid coordinate dynamic analysis. [for spacecraft attitude control

    Science.gov (United States)

    Likins, P.; Ohkami, Y.; Wong, C.

    1976-01-01

    The paper examines the validity of the assumption that certain appendage-distributed (modal) coordinates can be truncated from a system model without unacceptable degradation of fidelity in hybrid coordinate dynamic analysis for attitude control of spacecraft with flexible appendages. Alternative truncation criteria are proposed and their interrelationships defined. Particular attention is given to truncation criteria based on eigenvalues, eigenvectors, and controllability and observability. No definitive resolution of the problem is advanced, and exhaustive study is required to obtain ultimate truncation criteria.

  17. Abnormal atrial activation in young patients with lone atrial fibrillation

    DEFF Research Database (Denmark)

    Holmqvist, Fredrik; Olesen, Morten S; Tveit, Arnljot

    2011-01-01

    Aims Patients with a history of atrial fibrillation (AF) have previously been shown to have altered atrial conduction, as seen non-invasively using signal-averaged P-wave analysis. However, little is known about the P-wave morphology in patients in the early phases of AF with structurally normal ...

  18. Effect of hepatocyte growth factor and transforming growth factor-β1 on atrial fibroblasts fibrosis

    Institute of Scientific and Technical Information of China (English)

    张建成

    2012-01-01

    Objective To investigate the effect of hepatocyte growth factor (HGF) and transforming growth factor-β1 (TGFβ1) on the expression of α-smooth muscle actin(α-SMA) and collagen I in human atrial fibroblast in vitro, and to explore the possible molecular mechanism of atrial fibrosis in patients

  19. Strangulation and Necrosis of an Epiploic Appendage of the Sigmoid Colon in a Right Inguinal Hernia

    Directory of Open Access Journals (Sweden)

    Yuri N. Shiryajev

    2013-01-01

    Full Text Available An epiploic appendage of the sigmoid colon is considered to be an unusual type of inguinal hernia content. The strangulation of a sigmoid colon appendage into a right inguinal hernia is exclusively rare. We present a case of an 81-year-old female patient with severe cardiovascular comorbidities who was urgently admitted after an episode of strangulation and subsequent spontaneous reduction of a right inguinal hernia. The condition of the patient was stable, and an urgent operation was not indicated for three days after admission. However, we had to operate because the hernia strangulation recurred. In the hernia sac, a free fatty body (a separated and saponified epiploic appendage of the colon and a strangulated epiploic appendage of dolichosigmoid, with signs of necrosis, were found. Removal of the free fatty body and necrotic epiploic appendage and subsequent anterior-wall inguinal hernioplasty were successfully performed. In the world literature, this case may be the first report of a sigmoid epiploic appendage strangulation in a right inguinal hernia that is well documented by photography.

  20. Skin appendageal immune reactivity in a case of cutaneous lupus

    Directory of Open Access Journals (Sweden)

    Ana Maria Abreu Velez

    2011-10-01

    Full Text Available Background: Discoid lupus erythematosus is a cutaneous disease with a worldwide distribution, and its pathogenesis remains unclear. Case Report: A 41 year old male was evaluated for hair loss, in patches on the scalp. We studied selected adaptor proteins expressed in T, natural killer, neutrophil and mast cells; these proteins are important mediators for antigen receptor signaling in situ. Methods: Skin biopsies for hematoxylin and eosin examination, as well as for direct immunofluorescence and immunohistochemistry analysis were performed. Results: Hematoxylin and eosin staining demonstrated classic features of lupus with focal dermal scarring; epidermal atrophy was noted, with lymphohistiocytic infiltrates around the skin appendages. Direct immunofluoresence revealed classic, lupus band positive staining along the dermal/epidermal junction. In addition, immune reactants were identified in neurovascular areas, and around pilosebaceous units. Immunohistochemistry staining showed positive staining for the T-cell antigen receptor zeta chain, the linker for activation of T cells, myeloperoxidase, cyclo-oxygenase 2, melanoma-associated antigen 1, B cell leukemia/lymphoma-2 associated X protein, and BCL-2 markers. The positive staining was observed within the dermal inflammatory infiltrate, around pilosebaceous units, upper dermal blood vessels, and focally within eccrine sweat glands. Conclusions: The pathobiology of cutaneous lupus involves not only the epidermis, but also dermal pilosebaceous units, eccrine sweat glands and blood vessels. Further studies are recommended, especially in the light of presented data regarding T cell activation and proapototic molecules.

  1. Photodynamic Therapy and Skin Appendage Disorders: A Review

    Science.gov (United States)

    Megna, Matteo; Fabbrocini, Gabriella; Marasca, Claudio; Monfrecola, Giuseppe

    2017-01-01

    Photodynamic therapy (PDT) is a noninvasive treatment that utilizes light treatment along with application of a photosensitizing agent. In dermatology, PDT is commonly used and approved for the treatment of oncological conditions such as actinic keratosis, Bowen disease and superficial basal cell carcinoma. In the last 2 decades however, PDT has also been used for the treatment of several nonneoplastic dermatological diseases. The present review summarizes published data on PDT application in skin appendage disorders. Our literature review shows that: (a) PDT may be a suitable treatment for acne, folliculitis decalvans, hidradenitis suppurativa, nail diseases, and sebaceous hyperplasia; (b) there is a lack of agreement on PDT features (type, concentrations and incubation period of used substances, number and frequency of PDT sessions, optimal parameters of light sources, and patient characteristics [e.g., failure to previous treatments, disease severity, body surface area involved, etc.] which should guide PDT use in these diseases); (c) further research is needed to establish international guidelines helping dermatologists to choose PDT for the right patient at the right time.

  2. The role of atrial electrical remodeling in the progression of focal atrial ectopy to persistent atrial fibrillation

    NARCIS (Netherlands)

    Hobbs, WJC; Van Gelder, IC; Fitzpatrick, AP; Crijns, HJGM; Garratt, CJ

    1999-01-01

    Focal Atrial Fibrillation and Electrical Remodeling. Although atrial fibrillation- (AF) induced changes in atrial refractoriness (atrial electrical remodeling) have been demonstrated in a number of different animal models, the clinical significance of this process is unknown. We describe a patient i

  3. Effects of trimetazidine on atrial structural remodeling and platelet activation in dogs with atrial fibrillation

    Institute of Scientific and Technical Information of China (English)

    HAN Wei; LI Wei-min; ZHOU Hong-yan; HUO Hong; WEI Na; DONG Guo; CAO Yong; ZHOU Guo; YANG Shu-sen

    2009-01-01

    @@ Atrial fibrillation (AF) is one of the most common arrhythmias in clinical practice. AF results in electrophysiological alterations which involve increased atrial effective refractory period and atrial effective refractory period dispersion, reduced rate adaptation of atrial effective refractory period, and slowed atrial conduction.

  4. [Stroke. are there any difference between patients with or without patent foramen ovale in left atrial appendage systolic function?].

    Science.gov (United States)

    Contreras, Alejandro E; Perrote, Federico; Concari, Ignacio; Brenna, Eduardo J; Lucero, Cecilia

    2012-01-01

    Introducción: El objetivo del presente trabajo fue comparar la función sistólica de la orejuela de la aurícula izquierda (OAI) en un grupo de pacientes con y sin foramen oval permeable (FOP) quienes sufrieron eventos cerebrovasculares isquémicos. Material y métodos: Entre septiembre de 2010 y octubre de 2011, 17 pacientes fueron enviados para la realización de un ecocardiograma transesofágico (ETE) por haber sufrido un accidente cerebrovascular (ACV). Se definió FOP al pasaje de al menos una burbuja a través del septum interauricular con test de burbujas. Se comparó la velocidad sistólica en la orejuela entre los pacientes con y sin FOP y con un grupo control. Resultados: Fueron 8 mujeres y 9 hombres, con una edad media de 54,1 ± 19,5 años. Todos los pacientes habían sufrido un evento cerebrovascular isquémico, el 41,2% habían tenido ACV, el 52,9% crisis isquémica transitoria y el 5,9% amaurosis fugaz. En la evaluación con ETE, el 11,8% tuvo aneurisma del septum interauricular y el 35,3% FOP. La velocidad sistólica media de la OAI fue 66,3 ± 20,3 cm/seg. No hubo diferencia en la velocidad sistólica de la OAI entre pacientes con o sin FOP (67,5 ± 11,8 cm/seg vs 65,7 ± 24,3 cm/seg respectivamente, p= 0,87). El grupo control compuesto por 8 pacientes, 5 mujeres y 3 hombres, con una edad media de 39,5 ± 18 años, tuvo una velocidad sistólica de la OAI de 77,6 ± 28,9 cm/seg, sin diferencias significativas con los pacientes isquémicos. Conclusión: No hubo diferencias en la función sistólica de la OAI entre pacientes con y sin FOP con eventos cerebrovasculares isquemicos.

  5. Total plasma proANP increases with atrial dilatation in horses

    DEFF Research Database (Denmark)

    Van Der Vekens, N; Hunter, I; Timm, A

    2015-01-01

    Equine atrial natriuretic peptide (ANP) plasma concentrations are correlated with left atrial size. However, species-specific assays are lacking and the results from human assays are poorly reproducible. A new methodology called processing independent analysis (PIA) that measures the total pro......ANP product in plasma has proven to be successful in human medicine, but has never been used in horses. The aims were to establish an equine proANP reference interval by measurement of the total proANP product using PIA and to examine the proANP concentrations in horses with atrial dilatation. Sample...... stability was studied by comparison of storage at -80°C and -20°C. Plasma samples were obtained from 23 healthy horses, 12 horses with moderate or severe valvular regurgitation without atrial dilatation and 42 horses with valvular regurgitation and atrial dilatation. The proANP concentration...

  6. Atrial fibrillation: effects beyond the atrium?

    Science.gov (United States)

    Wijesurendra, Rohan S; Casadei, Barbara

    2015-03-01

    Atrial fibrillation (AF) is the most common sustained clinical arrhythmia and is associated with significant morbidity, mostly secondary to heart failure and stroke, and an estimated two-fold increase in premature death. Efforts to increase our understanding of AF and its complications have focused on unravelling the mechanisms of electrical and structural remodelling of the atrial myocardium. Yet, it is increasingly recognized that AF is more than an atrial disease, being associated with systemic inflammation, endothelial dysfunction, and adverse effects on the structure and function of the left ventricular myocardium that may be prognostically important. Here, we review the molecular and in vivo evidence that underpins current knowledge regarding the effects of human or experimental AF on the ventricular myocardium. Potential mechanisms are explored including diffuse ventricular fibrosis, focal myocardial scarring, and impaired myocardial perfusion and perfusion reserve. The complex relationship between AF, systemic inflammation, as well as endothelial/microvascular dysfunction and the effects of AF on ventricular calcium handling and oxidative stress are also addressed. Finally, consideration is given to the clinical implications of these observations and concepts, with particular reference to rate vs. rhythm control.

  7. Evolution of nubbin function in hemimetabolous and holometabolous insect appendages

    Science.gov (United States)

    Turchyn, Nataliya; Chesebro, John; Hrycaj, Steven; Couso, Juan P.; Popadić, Aleksandar

    2011-01-01

    Insects display a whole spectrum of morphological diversity, which is especially noticeable in the organization of their appendages. A recent study in a hemipteran, Oncopeltus fasciatus (milkweed bug), showed that nubbin (nub) affects antenna morphogenesis, labial patterning, the length of the femoral segment in legs, and the formation of a limbless abdomen. To further determine the role of this gene in the evolution of insect morphology, we analyzed its functions in two additional hemimetabolous species, Acheta domesticus (house cricket) and Periplaneta americana (cockroach), and re-examined its role in Drosophila. While both Acheta and Periplaneta nub-RNAi first nymphs develop crooked antennae, no visible changes are observed in the morphologies of their mouthparts and abdomen. Instead, the main effect is seen in legs. The joint between the tibia and first tarsomere (Ta-1) is lost in Acheta, which in turn, causes a fusion of these two segments and creates a chimeric nub-RNAi tibia-tarsus that retains a tibial identity in its proximal half and acquires a Ta-1 identity in its distal half. Similarly, our re-analysis of nub function in Drosophila reveals that legs lack all true joints and the fly tibia also exhibits a fused tibia and tarsus. Finally, we observe a similar phenotype in Periplaneta except that it encompasses different joints (coxa-trochanter and femur-tibia), and in this species we also show that nub expression in the legs is regulated by Notch signaling, as had previously been reported in flies and spiders. Overall, we propose that nub acts downstream of Notch on the distal part of insect leg segments to promote their development and growth, which in turn is required for joint formation. Our data represent the first functional evidence defining a role for nub in leg segmentation and highlight the varying degrees of its involvement in this process across insects. PMID:21708143

  8. Evolution of nubbin function in hemimetabolous and holometabolous insect appendages.

    Science.gov (United States)

    Turchyn, Nataliya; Chesebro, John; Hrycaj, Steven; Couso, Juan P; Popadić, Aleksandar

    2011-09-01

    Insects display a whole spectrum of morphological diversity, which is especially noticeable in the organization of their appendages. A recent study in a hemipteran, Oncopeltus fasciatus (milkweed bug), showed that nubbin (nub) affects antenna morphogenesis, labial patterning, the length of the femoral segment in legs, and the formation of a limbless abdomen. To further determine the role of this gene in the evolution of insect morphology, we analyzed its functions in two additional hemimetabolous species, Acheta domesticus (house cricket) and Periplaneta americana (cockroach), and re-examined its role in Drosophila melanogaster (fruit fly). While both Acheta and Periplaneta nub-RNAi first nymphs develop crooked antennae, no visible changes are observed in the morphologies of their mouthparts and abdomen. Instead, the main effect is seen in legs. The joint between the tibia and first tarsomere (Ta-1) is lost in Acheta, which in turn, causes a fusion of these two segments and creates a chimeric nub-RNAi tibia-tarsus that retains a tibial identity in its proximal half and acquires a Ta-1 identity in its distal half. Similarly, our re-analysis of nub function in Drosophila reveals that legs lack all true joints and the fly tibia also exhibits a fused tibia and tarsus. Finally, we observe a similar phenotype in Periplaneta except that it encompasses different joints (coxa-trochanter and femur-tibia), and in this species we also show that nub expression in the legs is regulated by Notch signaling, as had previously been reported in flies and spiders. Overall, we propose that nub acts downstream of Notch on the distal part of insect leg segments to promote their development and growth, which in turn is required for joint formation. Our data represent the first functional evidence defining a role for nub in leg segmentation and highlight the varying degrees of its involvement in this process across insects.

  9. Long-term results of a minimally invasive surgical pulmonary vein isolation and ganglionic plexi ablation for atrial fibrillation.

    Directory of Open Access Journals (Sweden)

    Shuai Zheng

    Full Text Available BACKGROUND: Ganglionated plexi (GP ablation has been become an adjunct to pulmonary vein isolation (PVI. This study describes the long-term results of minimally invasive surgical PVI, ablation of GPs, and exclusion of the left atrial appendage for atrial fibrillation (AF. METHODS: Long-term follow-up of 55 months was performed in 139 consecutive patients (age 58.3±20.8 years with symptomatic, drug-refractory lone AF who underwent minimally invasive surgical PVI, GPs ablation, and exclusion of the left atrial appendage. Success was defined as freedom from AF, atrial flutter, or atrial tachycardia off antiarrhythmic drugs. RESULTS: AF was paroxysmal in 77.7%, persistent in 12.2% and long-standing persistent in 10.1%. Single-procedure success rate was 71.7%, 59.4% and 46.6% at 12, 24 and 60 months respectively. Single-procedure success rate was 72.9%, 62.6% and 51.8% for paroxysmal AF, 64.7%, 35.3%, and 28.2% for persistent AF, 71.4%, 64.3% and 28.6% for long-standing persistent AF at 12, 24 and 60 months respectively. Duration of AF>24 months (hazard ratio [HR]: 3.09, 95% confidence interval [CI]: 1.51 to 6.32; p = 0.002, left atrial diameter≥40 mm (HR: 4.03, 95% CI: 1.88 to 8.65; p<0.001, early recurrence of AF (HR: 4.66, 95% CI: 2.25 to 9.63; p<0.001 independently predicted long-term recurrence of AF. There was no procedure-related death. One patient converted to median sternotomy because of uncontrolled bleeding. Two patients underwent perioperative cerebrovascular events. CONCLUSIONS: At nearly 5-year of clinical follow-up, single-procedure success rate of minimally invasive surgical PVI with GP ablation was 51.8% for paroxysmal AF, 28.2% for persistent AF, 28.6% for long-standing persistent AF after initial procedure. Patients with AF duration≤24 months, left atrial diameter<40 mm and no early recurrence of AF, had favorable outcomes.

  10. The human adult cardiomyocyte phenotype

    NARCIS (Netherlands)

    Bird, SD; Doevendans, PA; van Rooijen, MA; de la Riviere, AB; Hassink, RJ; Passier, R; Mummery, CL

    2003-01-01

    Aim: Determination of the phenotype of adult human atrial and ventricular myocytes based on gene expression and morphology. Methods: Atrial and ventricular cardiomyocytes were obtained from patients undergoing cardiac surgery using a modified isolation procedure. Myocytes were isolated and cultured

  11. Transcatheter left atrial appendage occlusion in patients with atrial fibrillation and a high bleeding risk using aspirin alone for post-implant antithrombotic therapy

    DEFF Research Database (Denmark)

    Korsholm, Kasper; Nielsen, Kirsten Melgaard; Jensen, Jesper Møller

    2016-01-01

    in a consecutive cohort (n=110) treated by ASA alone post-implantation. Primary outcome was device-related thrombosis, while secondary outcomes were ischemic stroke or major bleeding. Clinical follow-up was conducted after 6 weeks and 12 months with TEE and cardiac CT. 107 patients were included for analysis. 3...... patients were excluded due to mechanical valve prosthesis. CHA2DS2-VASc score was 4.4±1.6 and HAS-BLED 4.1±1.1. Successful implantation was obtained in all patients with a periprocedural complication rate of 4.6%. Median follow-up was 2.3 years, with a total of 265 patient-years. Device-related thrombosis...... was detected in 2/107 (1.9%) cases. Stroke occurred in 6/107 patients, with an annualized rate of 2.3%, which is a 61% risk reduction compared to the predicted rate. Annual risk of major bleeding was reduced by 57%. CONCLUSIONS: LAAO with the ACP or Amulet was safely performed with ASA monotherapy after...

  12. Effects of electrical and structural remodeling on atrial fibrillation maintenance: a simulation study.

    Science.gov (United States)

    Krogh-Madsen, Trine; Abbott, Geoffrey W; Christini, David J

    2012-01-01

    Atrial fibrillation, a common cardiac arrhythmia, often progresses unfavourably: in patients with long-term atrial fibrillation, fibrillatory episodes are typically of increased duration and frequency of occurrence relative to healthy controls. This is due to electrical, structural, and contractile remodeling processes. We investigated mechanisms of how electrical and structural remodeling contribute to perpetuation of simulated atrial fibrillation, using a mathematical model of the human atrial action potential incorporated into an anatomically realistic three-dimensional structural model of the human atria. Electrical and structural remodeling both shortened the atrial wavelength--electrical remodeling primarily through a decrease in action potential duration, while structural remodeling primarily slowed conduction. The decrease in wavelength correlates with an increase in the average duration of atrial fibrillation/flutter episodes. The dependence of reentry duration on wavelength was the same for electrical vs. structural remodeling. However, the dynamics during atrial reentry varied between electrical, structural, and combined electrical and structural remodeling in several ways, including: (i) with structural remodeling there were more occurrences of fragmented wavefronts and hence more filaments than during electrical remodeling; (ii) dominant waves anchored around different anatomical obstacles in electrical vs. structural remodeling; (iii) dominant waves were often not anchored in combined electrical and structural remodeling. We conclude that, in simulated atrial fibrillation, the wavelength dependence of reentry duration is similar for electrical and structural remodeling, despite major differences in overall dynamics, including maximal number of filaments, wave fragmentation, restitution properties, and whether dominant waves are anchored to anatomical obstacles or spiralling freely.

  13. Attitude maneuver of liquid-filled spacecraft with a flexible appendage by momentum wheel

    Institute of Scientific and Technical Information of China (English)

    Dan-Dan Yang; Bao-Zeng Yue; Wen-Jun Wu; Xiao-Juan Song; Le-Mei Zhu

    2012-01-01

    Attitude maneuver of liquid-filled spacecraft with an appendage as a cantilever beam by momentum wheel is studied.The dynamic equations are derived by conservation of angular momentum and force equilibrium principle.A feedback control strategy of the momentum wheel is applied for the attitude maneuver.The residual nutation of the spacecraft in maneuver process changes with some chosen parameters,such as steady state time,locations of the liquid container and the appendage,and appendage parameters.The results indicate that locations in the second and fourth quadrants of the body-fixed coordinate system and the second quadrant of the wall of the main body are better choices forplacing the liquid containers and the appendage than other locations if they can be placed randomly.Higher density and thicker cross section are better for lowering the residual nutation if they can be changed.Light appendage can be modeled as a rigid body,which results in a larger residual nutation than a flexible model though.The residual nutation decreases with increasing absolute value of the initial sloshing angular height.

  14. Management of atrial fibrillation marching towards a glorious future%心房颤动的治疗:前景光明

    Institute of Scientific and Technical Information of China (English)

    马长生; 陈新

    2010-01-01

    @@ 心房颤动(房颤)是最常见的持续性心律失常,内科治疗主要包括药物、导管消融、左心耳封堵等[1].%Great achievements have been made in management of atrial fibrillation (AF),including drug therapy,catheter ablation and percutaneous closure of left atrial appendage in recent years.The development of new generation anticoagulation drugs will hopefully be a landmark in the management of AF.It was shown in RELY study that dabigatran,a direct competitive inhibitor of thrombin,was associated with lower rates of stroke and systemic embolism but similar rates of major hemorrhage as compared with warfarin.ATHENA study revealed that dronedarone reduced the incidence of stroke and hospitalization due to cardiovascular events or death in patients with AF.Dmnedarone,a new antiarrhythmie drug,was approved by FDA for management of AF.Catheter ablation of AF has emerged as a mainstream therapy.it was shown in a recent study that the incidence of stroke in the patients underwent Successful ablation was only 0.07%.This study estabolished the fact that Successful catheter ablation of AF could improve the outcome of patients with AF.In the field of device therapy of AF,PROTECT-AF confirmed that percutaneous closure of left atrial appendage was not inferior to warfarin with regard to prevention of stroke in patients with AF.

  15. Atrial fibrillation and heart failure: is atrial fibrillation a disease?

    Science.gov (United States)

    Tilman, V

    2014-09-01

    Atrial fibrillation in heart failure often occur together. The relationship between atrial fibrillation and heart failure has remained a subject of research. The main manifestation of the violation of hydrodynamics in heart failure is the increased end-diastolic pressure, which is transmitted through the intercommunicated system (left ventricle-left atrium-pulmonary veins-alveolar capillaries) causing increased pulmonary wedge pressure with the danger for pulmonary edema. End-diastolic pressure is the sum of left ventricle diastolic pressure and left atrial systolic pressure. Stopping the mechanical systole of the left atrium can reduce the pressure in the system in heart failure. Atrial fibrillation stops the mechanical systole of the left atrium and decreases the intercommunicating pressure and pulmonary wedge pressure. It is possible that atrial fibrillation is a mechanism for protection from increasing end-diastolic pressure and pulmonary wedge pressure, and prevents the danger of pulmonary edema. This hypothesis may explain the relationship between heart failure and atrial fibrillation and their frequent association.

  16. Case report: successful repeat tricuspid valve replacement combined with atrial flutter ablation during correction of Ebstein's anomaly

    Directory of Open Access Journals (Sweden)

    Bockeria L.A.

    2013-09-01

    Full Text Available Patients with Ebstein's anomaly often suffer from a variety of arrhythmias, such as paroxysmal supraventricular tachycardia, atrial fibrillation and atrial flutter, which in turn adversely affects the prognosis of these patients. This is why early diagnosis and treatment can reduce the risk of sudden cardiac death. Patient V. 34 years old admitted to the department of surgical treatment of interactive pathology Bakoulev's Сenter for Сardiovascular Surgery RAMS. In 1987 the patient underwent tricuspid valve replacement with bioprosthesis made of aortic valve of a pig. After the operation he felt well. Worsening of the disease was noticed in July 2012. Due to worsening of the symptoms the patient admitted to a hospital. Dysfunction of bioprosthesis with calcification and insufficiency were revealed. Atrial flutter was diagnosed as well. 19.10.2012 redo tricuspid valve replacement with bioprosthesis Bioglis (28 in diameter, cryoablation of right isthmus and the dase of right atrial appendage with Atri Cure system. The patient was discharged on postoperative day 12. He felt well and was sent to supervision of cardiologist for follow-up.

  17. [Nosology and mechanism of monomorphous atrial tachycardia].

    Science.gov (United States)

    Puech, P

    1990-12-01

    Monomorphous atrial tachycardias have been classified taking into account the ectopic rhythm rate, atrial wave morphology, the mode of activation of the atrial studied by endocavitary cartography, stimulation tests and their natural history. Atrial flutter is a right intra-atrial macroreentry of anticlockwise (common flutter) or clockwise (atypical flutter) rotation, maintained by anisotropic conduction around two pivotal zones located at the posterior and inferior part of the atrium. Tachycardia is made possible by the existence of an excitable zone on the circuit. Paroxysmal atrial tachycardias are far more often linked to localised reentry (sino-atrial or intra-atrial microreentry) than to provoked activity, stimulation tests enabling the distinction to be made. "Digitalis tachycardias" must be seen in the context of activity induced by late post-potential. Focal atrial tachycardias linked to ectopic automatism are a separate entity. They follow a chronic course in the young individual and may lead to a cardiomyopathy purely due to the rhythm abnormality.

  18. Skin appendage-derived stem cells: cell biology and potential for wound repair.

    Science.gov (United States)

    Xie, Jiangfan; Yao, Bin; Han, Yutong; Huang, Sha; Fu, Xiaobing

    2016-01-01

    Stem cells residing in the epidermis and skin appendages are imperative for skin homeostasis and regeneration. These stem cells also participate in the repair of the epidermis after injuries, inducing restoration of tissue integrity and function of damaged tissue. Unlike epidermis-derived stem cells, comprehensive knowledge about skin appendage-derived stem cells remains limited. In this review, we summarize the current knowledge of skin appendage-derived stem cells, including their fundamental characteristics, their preferentially expressed biomarkers, and their potential contribution involved in wound repair. Finally, we will also discuss current strategies, future applications, and limitations of these stem cells, attempting to provide some perspectives on optimizing the available therapy in cutaneous repair and regeneration.

  19. Atrial Electrophysiological Remodeling and Fibrillation in Heart Failure

    Science.gov (United States)

    Pandit, Sandeep V.; Workman, Antony J.

    2016-01-01

    Heart failure (HF) causes complex, chronic changes in atrial structure and function, which can cause substantial electrophysiological remodeling and predispose the individual to atrial fibrillation (AF). Pharmacological treatments for preventing AF in patients with HF are limited. Improved understanding of the atrial electrical and ionic/molecular mechanisms that promote AF in these patients could lead to the identification of novel therapeutic targets. Animal models of HF have identified numerous changes in atrial ion currents, intracellular calcium handling, action potential waveform and conduction, as well as expression and signaling of associated proteins. These studies have shown that the pattern of electrophysiological remodeling likely depends on the duration of HF, the underlying cardiac pathology, and the species studied. In atrial myocytes and tissues obtained from patients with HF or left ventricular systolic dysfunction, the data on changes in ion currents and action potentials are largely equivocal, probably owing mainly to difficulties in controlling for the confounding influences of multiple variables, such as patient’s age, sex, disease history, and drug treatments, as well as the technical challenges in obtaining such data. In this review, we provide a summary and comparison of the main animal and human electrophysiological studies to date, with the aim of highlighting the consistencies in some of the remodeling patterns, as well as identifying areas of contention and gaps in the knowledge, which warrant further investigation. PMID:27812293

  20. Idiopathic giant right atrial aneurysm

    Science.gov (United States)

    Uppu, Santosh C; Sachdeva, Ritu; Imamura, Michiaki

    2013-01-01

    A 2-year-old boy with an incidental finding of massive cardiomegaly on a chest X-ray was diagnosed with a giant right atrial aneurysm upon further investigation with echocardiography. The patient underwent successful surgical reduction of the right atrium and closure of the patent foramen ovale to prevent thromboembolic complications and to lower the risk of atrial arrhythmias. The resected atrium had paper-thin walls and pathological features of interstitial fibrosis with endocardial thickening. PMID:23626440

  1. Idiopathic giant right atrial aneurysm

    OpenAIRE

    Uppu, Santosh C; Ritu Sachdeva; Michiaki Imamura

    2013-01-01

    A 2-year-old boy with an incidental finding of massive cardiomegaly on a chest X-ray was diagnosed with a giant right atrial aneurysm upon further investigation with echocardiography. The patient underwent successful surgical reduction of the right atrium and closure of the patent foramen ovale to prevent thromboembolic complications and to lower the risk of atrial arrhythmias. The resected atrium had paper-thin walls and pathological features of interstitial fibrosis with endocardial thicken...

  2. Idiopathic giant right atrial aneurysm

    Directory of Open Access Journals (Sweden)

    Santosh C Uppu

    2013-01-01

    Full Text Available A 2-year-old boy with an incidental finding of massive cardiomegaly on a chest X-ray was diagnosed with a giant right atrial aneurysm upon further investigation with echocardiography. The patient underwent successful surgical reduction of the right atrium and closure of the patent foramen ovale to prevent thromboembolic complications and to lower the risk of atrial arrhythmias. The resected atrium had paper-thin walls and pathological features of interstitial fibrosis with endocardial thickening.

  3. Neovascularization in Left Atrial Myxoma

    Science.gov (United States)

    Dubey, Laxman; Chaurasia, Amit Kumar

    2012-01-01

    Abstract We report a case with a left atrial mass who underwent coronary angiography to rule out coronary artery disease. Coronary angiography revealed an anomalous tortuous vascular structure originating from the left circumflex coronary artery to the left atrial tumor suggestive of neovascularization. Preoperative coronary angiography is useful for coronary artery evaluation and also provides additional information regarding the feeding vessel supplying the mass. PMID:24757609

  4. Comparative study of atrial fibrillation and AV conduction in mammals

    NARCIS (Netherlands)

    Meijler, F.L.; Tweel, I. van der

    1987-01-01

    Atrial fibrillation is one ofthe most common cardiac arrhythmias in humans. It a1so occurs quite frequent1y in dogs and horses. Comparative study of this arrhythmia may contribute to better understanding of the pathophysiologica1 mechanisms involved. In this study, we present a quantitative analysis

  5. The chelifores of sea spiders (Arthropoda, Pycnogonida) are the appendages of the deutocerebral segment.

    Science.gov (United States)

    Brenneis, Georg; Ungerer, Petra; Scholtz, Gerhard

    2008-01-01

    Within the last decade, gene expression patterns and neuro-anatomical data have led to a new consensus concerning the long-debated association between anterior limbs and neuromeres in the arthropod head. According to this new view, the first appendage in all extant euarthropods is innervated by the second neuromere, the deutocerebrum, whereas the anterior-most head region bearing the protocerebrum lacks an appendage. This stands in contrast to the clearly protocerebrally targeted "antennae" of Onychophora and to some evidence for protocerebral limbs in fossil euarthropod representatives. Yet, the latter "frontal appendages" or "primary antennae" have most likely been reduced or lost in the lineage, leading to extant taxa. Surprisingly, a recent neuro-anatomical study on a pycnogonid challenged this evolutionary scenario, reporting a protocerebral innervation of the first appendages, the chelifores. However, this interpretation was soon after questioned by Hox gene expression data. To re-evaluate the unresolved controversy, we analyzed neuro-anatomy and neurogenesis in four pycnogonid species using immunohistochemical techniques. We clearly show the postprotocerebral innervation of the chelifores, which is resolved as the plesiomorphic condition in pycnogonids when evaluated against a recently published comprehensive phylogeny. By providing direct morphological support for the deutocerebral status of the cheliforal ganglia, we reconcile morphological and gene expression data and argue for a corresponding position between the anterior-most appendages in all extant euarthropods. Consequently, other structures have to be scrutinized to illuminate the fate of a presumptive protocerebral appendage in recent euarthropods. The labrum and the "frontal filaments" of some crustaceans are possible candidates for this approach.

  6. Probucol attenuates atrial autonomic remodeling in a canine model of atrial fibrillation produced by prolonged atrial pacing

    Institute of Scientific and Technical Information of China (English)

    GONG Yong-tai; LI Wei-min; LI Yue; YANG Shu-sen; SHENG Li; YANG Ning; SHAN Hong-bo; XUE Hong-jie; LIU Wei; YANG Bao-feng; DONG De-li; LI Bao-xin

    2009-01-01

    Background We hypothesize that increased atrial oxidative stress and inflammation may play an important role in atrial nerve sprouting and heterogeneous sympathetic hyperinnervation during atrial fibrillation (AF). To test the hypothesis, we examined whether the antioxidant and anti-inflammatory treatment with probucol attenuates atrial autonomic remodeling in a canine model of AF produced by prolonged rapid right atrial pacing. Methods Twenty-one dogs were divided into a sham-operated group, a control group and a probucol group. Dogs in the control group and probucol group underwent right atrial pacing at 400 beats per minute for 6 weeks, and those in the probucol group received probucol 1 week before rapid atrial pacing until pacing stopped. After 6-week rapid atrial pacing, general properties including left atrial structure and function, atrial hemodynamics and the inducibility and duration of AF were measured in all the groups. Atrial oxidative stress markers and serum C-reactive protein (CRP) concentration were estimated. The degree of nerve sprouting and sympathetic innervation at the right atrial anterior wall (RAAW) and the left atrial anterior wall (LAAW) were quantified by immunohistochemistry, atdal norepinephrine contents were also detected. Atrial beta-nerve growth factor (beta-NGF) mRNA and protein expression at the RAAW and LAAW were assessed by real-time quantitative RT-PCR and Western blotting respectively. Results Atrial tachypacing induced significant nerve sprouting and heterogeneous sympathetic hyperinnervation, and the magnitude of nerve sprouting and hyperinnervation was higher in the RAAW than in the LAAW. Atrial beta-NGF mRNA and protein levels were significantly increased at the RAAW and LAAW, and the upregulation of beta-NGF expression was greater at the RAAW than at the LAAW in the control group. The beta-NGF protein level was positively correlated with the density of sympathetic nerves in all groups. Probucol decreased the increase of

  7. Plasma atrial natriuretic peptide and spontaneous diuresis in sick neonates.

    OpenAIRE

    Kojima, T; Hirata, Y; Fukuda, Y; Iwase, S.; Kobayashi, Y.

    1987-01-01

    Plasma concentrations of immunoreactive human atrial natriuretic peptide (human ANP) were sequentially determined in 12 infants with respiratory distress syndrome (RDS) or meconium aspiration syndrome (MAS) during various phases of diuresis to elucidate the role of human ANP in the occurrence of spontaneous diuresis in the newborn. Plasma immunoreactive ANP concentrations during the diuretic as well as the maximum diuretic phase were significantly (p less than 0.001) higher than during the pr...

  8. Amplatzer Cardiac Plug for Stroke Prevention in Patients with Atrial Fibrillation and Bigger Left Atrial Appendix Size.

    Science.gov (United States)

    Yuniadi, Yoga; Hanafy, Dicky A; Raharjo, Sunu B; Soeryo, Ario; Yasmina, IIf; Soesanto, Amiliana M

    2016-12-01

    Left atrial appendage (LAA) dimensions have been shown as an independent predictor of higher risk for stroke in AF patients. Little data exist on the outcomes after LAA closure in patients with nonvalvular atrial fibrillation (NVAF) who have relatively bigger LAA size. This study aims to evaluate the results associated with LAA closure with the Amplatzer cardiac plug (ACP, AGA, St. Jude Medical, Minneapolis, MN) in bigger LAA size. A total of 25 patients with NVAF underwent LAA closure with the ACP device. All patients received short-term (up to 3 months) dual-antiplatelet therapy (clopidogrel and aspirin) after the procedure and aspirin only thereafter. A transesophageal echocardiography was performed in all patients at the 3- and 6-month follow-ups. No patient was lost to follow-up (≥ 12 months in all patients). The mean age, CHA2DS2-VASc score, and HAS-BLED score were 66.2 ± 8.79 years; 3.2 ± 1.46 and 2.4 ± 1.0, respectively. The average sizes of the LAA landing zone and ostium were 23.08 ± 5.0 and 24.9 ± 4.4 mm, respectively. The procedure was successful in 23 (92%) patients and was canceled in 2 (8%) patients due to huge LAA dimensions. In 56% of the patients "pull and release" technique is needed to appropriately implant the ACP. During a mean follow-up of 12 months, no cases of periprocedural stroke and no mortality were observed. In patients with NVAF at high risk of cardioembolic events and big LAA size, LAA closure using the ACP device is safe and effective.

  9. Left atrial electrophysiologic feature specific for the genesis of complex fractionated atrial electrogram during atrial fibrillation.

    Science.gov (United States)

    Hoshiyama, Tadashi; Yamabe, Hiroshige; Koyama, Junjiroh; Kanazawa, Hisanori; Ogawa, Hisao

    2016-05-01

    Complex fractionated atrial electrogram (CFAE) has been suggested to contribute to the maintenance of atrial fibrillation (AF). However, electrophysiologic characteristics of the left atrial myocardium responsible for genesis of CFAE have not been clarified. Non-contact mapping of the left atrium was performed at 37 AF onset episodes in 24 AF patients. Electrogram amplitude, width, and conduction velocity were measured during sinus rhythm, premature atrial contraction (PAC) with long- (L-PAC), short- (S-PAC) and very short-coupling intervals (VS-PAC). These parameters were compared between CFAE and non-CFAE regions. Unipolar electrogram amplitude was higher in CFAE than non-CFAE during sinus rhythm, L-, S- and VS-PAC (1.82 ± 0.73 vs. 1.13 ± 0.38, p genesis of CFAE.

  10. Effect of nifekalant on acute electrical remodelling in rapid atrial pacing canine model

    Institute of Scientific and Technical Information of China (English)

    TANG Min; ZHANG Shu; SUN Qi; HUA Wei; HUANG Cong-xin

    2006-01-01

    Background Nifekalant may prevent atrial fibrillation (AF) and possibly be useful in treatment of atrial tachyarrhythmia in patients with severe heart failure. This study investigated the electophysiologic effect of nifekalant on the acute atrial remodeling in rapid atrial pacing (RAP) model of canine.Methods Twelve mongrel dogs subjected to rapid stimulation (400 beats/min) at left atrial appendage (LAA)for 24 hours, were randomized into the control group (rapid pacing only, n=6) and the nifekalant group (intravenous nifekalant therapy immediately after RAP, n=6). Atrial electrophysiological parameters were measured in right atrium, coronary sinus, LAA, posterior wall of left atrium (PWLA) and left superior pulmonary vein (LSPV), before and after the RAP.Results In the control group, the effective refractory periods (ERP) were shortened greatly at all sites, paced dogs had substantially shorter ERPs in the high right atrium, LAA, and LSPV, but fewer changes in the PWLA,the coefficient variation of ERP (COV ERP) was increased significantly. After rapid atrial stimulation, the inducibility of AF increased significantly [induction number: pre-RAP vs post-RAP, 1.00± 0.89 vs 8.17 ± 2.79,P<0.01; duration of AF: pre-RAP vs post-RAP, (450.34± 362.59) ms vs (9975.77 ±4376.99) ms, P<0.01]. In the nifekalant group, although the ERPs were prolonged at all sites compared with those in pre-RAP state, only the value at LSPV differed significantly from that in pre-RAP state [pre-RAP vs post-RAP, (102.50±5.24) ms vs (132.51 ±5.20) ms, P<0.01]; the COV ERP did not change statistically in this group. The inducibility of AF slightly increased but insignificantly after pacing [induction number: pre-RAP vs post-RAP, 0.83 ±0.75 vs 1.67±0.82, P=0.19; duration of AF: pre-RAP vs post-RAP, (378.67±317.88) ms vs (1124.08±1109.77) ms,P=0.06]. Conduction time values did not alter significantly in either of the two groups after RAP.Conclusions In canine RAP model, nifekalant

  11. Implantation of Lumenless Pacing Leads at the Inter-atrial Septum and Right Ventricular Outflow Tract with Deflectable Catheter-sheath

    Institute of Scientific and Technical Information of China (English)

    Rong BAI; Ruth KAM; Chi Keong CHING; Li Fern HSU; Wee Siong TEO

    2008-01-01

    Current permanent fight ventricular and fight atrial endocardial pacing leads are implanted utilizing a central lumen stylet. Right ventricular apex pacing initiates an abnormal asyno chronous electrical activation pattern, which results in asynchronous ventricular contraction and re-laxation. When pacing from right atrial appendage, the conduction time between two atria will be prolonged, which results in heterogeneity for both depolarization and repolarization. Six patients with Class Ⅰ indication for permanent pacing were implanted with either single chamber or dual chamber pacemaker. The SelectSecure 3830 4-French (Fr) lumenless lead and the SelectSite C304 8.5-Fr steerable catheter-sheath (Medtronic Inc., USA) were used. Pre-selected pacing sites included inter-atrial septum and right ventricular outflow tract, which were defined by ECG and fluoroscopic criteria. All the implanting procedures were successful without complication. Testing results (mean atrial pacing threshold: 0.87 V; mean P wave amplitude: 2.28 mV; mean ventricular pacing threshold:0.53V; mean R wave amplitude: 8.75 mV) were satisfactory. It is concluded that implantation of a 4-Fr lumenless pacing lead by using a streerable catheter-sheath to achieve inter-atrial septum or right ventricular outflow tract pacing is safe and feasible.

  12. Origin of archosaurian integumentary appendages: the bristles of the wild turkey beard express feather-type beta keratins.

    Science.gov (United States)

    Sawyer, Roger H; Washington, Lynette D; Salvatore, Brian A; Glenn, Travis C; Knapp, Loren W

    2003-06-15

    The discovery that structurally unique "filamentous integumentary appendages" are associated with several different non-avian dinosaurs continues to stimulate the development of models to explain the evolutionary origin of feathers. Taking the phylogenetic relationships of the non-avian dinosaurs into consideration, some models propose that the "filamentous integumentary appendages" represent intermediate stages in the sequential evolution of feathers. Here we present observations on a unique integumentary structure, the bristle of the wild turkey beard, and suggest that this non-feather appendage provides another explanation for some of the "filamentous integumentary appendages." Unlike feathers, beard bristles grow continuously from finger-like outgrows of the integument lacking follicles. We find that these beard bristles, which show simple branching, are hollow, distally, and express the feather-type beta keratins. The significance of these observations to explanations for the evolution of archosaurian integumentary appendages is discussed.

  13. Late atypical atrial flutter after ablation of atrial fibrillation.

    Science.gov (United States)

    Ferreira, Raquel; Primo, João; Adão, Luís; Gonzaga, Anabela; Gonçalves, Helena; Santos, Rui; Fonseca, Paulo; Santos, José; Gama, Vasco

    2016-10-01

    Cardiac surgery for structural heart disease (often involving the left atrium) and radiofrequency catheter ablation of atrial fibrillation have led to an increased incidence of regular atrial tachycardias, often presenting as atypical flutters. This type of flutter is particularly common after pulmonary vein isolation, especially after extensive atrial ablation including linear lesions and/or defragmentation. The authors describe the case of a 51-year-old man, with no relevant medical history, referred for a cardiology consultation in 2009 for paroxysmal atrial fibrillation. After failure of antiarrhythmic therapy, he underwent catheter ablation, with criteria of acute success. Three years later he again suffered palpitations and atypical atrial flutter was documented. The electrophysiology study confirmed the diagnosis of atypical left flutter and reappearance of electrical activity in the right inferior pulmonary vein. This vein was again ablated successfully and there has been no arrhythmia recurrence to date. In an era of frequent catheter ablation it is essential to understand the mechanism of this arrhythmia and to recognize such atypical flutters.

  14. Novel nonpharmacologic approaches for stroke prevention in atrial fibrillation: results from clinical trials

    Directory of Open Access Journals (Sweden)

    Proietti R

    2015-01-01

    Full Text Available Riccardo Proietti,1,2 Jacqueline Joza,1 Andrea Arensi,2 Michael Levi,1 Vincenzo Russo,3 Apostolos Tzikas,4 Paolo Danna,2 Antonio Sagone,2 Maurizio Viecca,2 Vidal Essebag1,5 1McGill University Health Center, Montreal, QC, Canada; 2Cardiology Department, Luigi Sacco Hospital, Milano, Italy; 3Cardiology Department, Second University of Naples, Monaldi Hospital, Naples, Italy; 4Interbalkan European Medical Centre, Thessaloniki, Greece; 5Hôpital Sacré-Coeur de Montréal, Montreal, QC, Canada Abstract: Atrial fibrillation (AF, the most common cardiac arrhythmia, confers a 5-fold risk of stroke that increases to 17-fold when associated with mitral stenosis. At this time, the most effective long-term solution to protect patients from stroke and thromboembolism is oral anticoagulation, either with vitamin K antagonists (VKAs or a novel oral anticoagulant (NOAC. Despite the significant benefits they confer, both VKAs and NOACs are underused because of their increased potential for bleeding, and VKAs are underused because of their narrow therapeutic range, need for regular international normalized ratio checks, and interactions with food or medications. In patients with nonvalvular AF, approximately 90% of strokes originate from the left atrial appendage (LAA; in patients with rheumatic mitral valve disease, many patients (60% have strokes that originate from the left atrium itself. Surgical LAA amputation or closure, although widely used to reduce stroke risk in association with cardiac surgery, is not currently performed as a stand-alone operation for stroke risk reduction because of its invasiveness. Percutaneous LAA closure, as an alternative to anticoagulation, has been increasingly used during the last decade in an effort to reduce stroke risk in nonvalvular AF. Several devices have been introduced during this time, of which one has demonstrated noninferiority compared with warfarin in a randomized controlled trial. This review describes the

  15. Assessment of Mitochondrial Dysfunction and Monoamine Oxidase Contribution to Oxidative Stress in Human Diabetic Hearts

    Directory of Open Access Journals (Sweden)

    O. M. Duicu

    2016-01-01

    Full Text Available Mitochondria-related oxidative stress is a pathomechanism causally linked to coronary heart disease (CHD and diabetes mellitus (DM. Recently, mitochondrial monoamine oxidases (MAOs have emerged as novel sources of oxidative stress in the cardiovascular system and experimental diabetes. The present study was purported to assess the mitochondrial impairment and the contribution of MAOs-related oxidative stress to the cardiovascular dysfunction in coronary patients with/without DM. Right atrial appendages were obtained from 75 patients randomized into 3 groups: (1 Control (CTRL, valvular patients without CHD; (2 CHD, patients with confirmed CHD; and (3 CHD-DM, patients with CHD and DM. Mitochondrial respiration was measured by high-resolution respirometry and MAOs expression was evaluated by RT-PCR and immunohistochemistry. Hydrogen peroxide (H2O2 emission was assessed by confocal microscopy and spectrophotometrically. The impairment of mitochondrial respiration was substrate-independent in CHD-DM group. MAOs expression was comparable among the groups, with the predominance of MAO-B isoform but no significant differences regarding oxidative stress were detected by either method. Incubation of atrial samples with MAOs inhibitors significantly reduced the H2O2 in all groups. In conclusion, abnormal mitochondrial respiration occurs in CHD and is more severe in DM and MAOs contribute to oxidative stress in human diseased hearts with/without DM.

  16. Pathological study on right atrium myocardium in rheumatic heart disease patients with atrial fibrillation

    Institute of Scientific and Technical Information of China (English)

    DUAN Xiang-ying; ZHANG Bao-ren; LI Li

    2002-01-01

    Objective:To study the pathological basis of right atrial fibrillation in rheumatic heart disease (RHD) patients with atrial fibrillation (AF). Methods: Twenty-nine patients with mitral valve replacement of RHD were divided into AF group (n= 13) and sinus rhythm group (SN group) (n= 16). There was no significant statistical difference in clinical factors between the 2 groups. During the operation of valve replacement, the samples of right atrial appendages were taken and the qualitative and quantitative study were made by light microscopy and electron microscopy. Results: (1) Light microscope: The interstitial fibrosis and the arrangement of myocardium was more disordered in AF group than that in SN group. However, no statistic difference was found in interstitial fibrosis and cellar hypertrophy degree between the 2 groups. (2) Electron microscope: Mitochondrial crosta broke and dissolved obviously in AF group. The mitochondrial volume in AF group was smaller than that in SN group. Volume density, average area and average perimeter in AF group were less than that in SN group; specific surface in AF group was bigger than that in SN group. There was significant difference of above factors between the 2 groups; but there was no significant difference of surface density and numerical density on area in the 2 groups. Volume density of myofibril in AF group and SN group were less than that in SN group. (3)Split of Intercalated disc(ID) gap was found in AF group, and there was marrowing and floccular substance in ID gap. Conclusion: There were significant differences in the pathological changes of right atrial myocardium between AF and SN with RHD, these changes may be the important pathological basis for RA fibrillation of AF patients with RHD.

  17. Dual-enhancement cardiac computed tomography for assessing left atrial thrombus and pulmonary veins before radiofrequency catheter ablation for atrial fibrillation.

    Science.gov (United States)

    Hur, Jin; Pak, Hui-Nam; Kim, Young Jin; Lee, Hye-Jeong; Chang, Hyuk-Jae; Hong, Yoo Jin; Choi, Byoung Wook

    2013-07-15

    Noninvasive imaging that provides anatomic information while excluding intracardiac thrombus would be of significant clinical value for patients referred for catheter ablation of atrial fibrillation (AF). This study assessed the diagnostic performance of a dual-enhancement single-phase cardiac computed tomography (CT) protocol for thrombus and circulatory stasis detection in AF patients before catheter ablation. We studied 101 consecutive symptomatic AF patients (71 men and 30 women; mean age, 61.8 years) who were scheduled to have catheter ablation. All patients had undergone pre-AF ablation CT imaging and transesophageal echocardiography on the same day. CT was performed with prospective electrocardiographic gating, and scanning began 180 seconds after the test bolus. Mean left atrial appendage (LAA)/ascending aorta Hounsfield unit (HU) ratios were measured on CT images. Among the 101 patients, 9 thrombi and 18 spontaneous echo contrasts were detected by transesophageal echocardiography. The overall sensitivity, specificity, positive predictive value, and negative predictive value of CT for the detection of thrombi in the LAA were 89%, 100%, 100%, and 99%, respectively. The mean LAA/ascending aorta HU ratios were significantly different between thrombus and circulatory stasis (0.17 vs 0.33, p = 0.002). Dual-enhancement single-scan cardiac CT is a sensitive modality for detecting and differentiating LAA thrombus and circulatory stasis.

  18. Detection of left atrial thrombus in patients with mitral stenosis and atrial fibrillation: retrospective comparison of two-phase computed tomography, transoesophageal echocardiography and surgical findings

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Bo Hwa; Ko, Sung Min [Konkuk University Medical Center, Konkuk University School of Medicine, Department of Radiology, Research Institute of Medical Science, Seoul (Korea, Republic of); Hwang, Hweung Kon [Konkuk University Medical Center, Konkuk University School of Medicine, Department of Cardiology, Seoul (Korea, Republic of); Song, Meong Gun; Shin, Je Kyoun [Konkuk University Medical Center, Konkuk University School of Medicine, Department of Thoracic surgery, Seoul (Korea, Republic of); Kang, Woon Seok; Kim, Tae-Yop [Konkuk University Medical Center, Konkuk University School of Medicine, Department of Anesthesiology, Seoul (Korea, Republic of)

    2013-11-15

    This retrospective study aims to assess the accuracy of two-phase computed tomography (CT) and transoesophageal echocardiography (TEE) for the detection of left atrial (LA) thrombus in patients with mitral stenosis (MS) and atrial fibrillation (AF), by using intraoperative findings as the reference standard. Preoperative two-phase CT and intraoperative TEE were performed in 106 patients with MS and AF. The ratio (LAA/AA{sub L}) of Hounsfield units (HU) in the LA appendage (LAA) to the ascending aorta (AA) was calculated on the late-phase CT image. LA echodense masses on TEE and LA filling defects on two-phase CT were observed in 29 and 39 patients, respectively. Thirty-five LA thrombi were identified at surgery in 27 patients. Compared with the intraoperative findings, per-patient sensitivity, specificity, positive and negative predictive values of two-phase CT were 100 %, 85 %, 69 % and 100 %, and those by using TEE were 93 %, 95 %, 86 % and 97 % in detecting LAA thrombus. After adopting the cut-off value of 0.5 for the LAA/AA{sub L} HU ratio, the specificity and positive predictive value of two-phase CT were increased to 96 % and 90 %, respectively. Two-phase CT with a cut-off value of LAA/AA{sub L} HU ratio of 0.5 provides high performance for the detection of LAA thrombus. (orig.)

  19. Left Atrial Linear Ablation of Paroxysmal Atrial Fibrillation Guided by Three-dimensional Electroanatomical System

    DEFF Research Database (Denmark)

    Zhang, Dai-Fu; Li, Ying; Qi, Wei-Gang

    2005-01-01

    Objective To investigate the safety and efficacy of Left atrial linear ablation of paroxysmal atrial fibrillation guided by three-dimensional electroanatomical system. Methods 29 patients with paroxysmal atrial fibrillation in this study. A nonfluoroscopic mapping system was used to generate a 3D...... attacks unchanged. No pulmonary vein narrowing was observed. Conclusion Left atrial linear ablation of paroxysmal atrial fibrillation guided by three-dimensional electroanatomical system was safe and effective....

  20. Passive control of a falling sphere by elliptic-shaped appendages

    CERN Document Server

    Lācis, Uǧis; Mazzino, Andrea; Bagheri, Shervin

    2016-01-01

    The majority of investigations characterizing the motion of single or multiple particles in fluid flows consider canonical body shapes, such as spheres, cylinders, discs, etc. However, protrusions on bodies -- being either as surface imperfections or appendages that serve a function -- are ubiquitous in both nature and applications. In this work, we characterize how the dynamics of a sphere with an axis-symmetric wake is modified in the presence of thin three-dimensional elliptic-shaped protrusions. By investigating a wide range of three-dimensional appendages with different aspect ratios and lengths, we clearly show that the sphere with an appendage may robustly undergo an inverted-pendulum-like (IPL) instability. This means that the position of the appendage placed behind the sphere and aligned with the free-stream direction is unstable, in a similar way that an inverted pendulum is unstable under gravity. Due to this instability, non-trivial forces are generated on the body, leading to turn and drift, if t...

  1. Space robots with flexible appendages: Dynamic modeling, coupling measurement, and vibration suppression

    Science.gov (United States)

    Meng, Deshan; Wang, Xueqian; Xu, Wenfu; Liang, Bin

    2017-05-01

    For a space robot with flexible appendages, vibrations of flexible structure can be easily excited during both orbit and/or attitude maneuvers of the base and the operation of the manipulators. Hence, the pose (position and attitude) of the manipulator's end-effector will greatly deviate from the desired values, and furthermore, the motion of the manipulator will trigger and exacerbate vibrations of flexible appendages. Given lack of the atmospheric damping in orbit, the vibrations will last for quite a while and cause the on-orbital tasks to fail. We derived the rigid-flexible coupling dynamics of a space robot system with flexible appendages and established a coupling model between the flexible base and the space manipulator. A specific index was defined to measure the coupling degree between the flexible motion of the appendages and the rigid motion of the end-effector. Then, we analyzed the dynamic coupling for different conditions, such as modal displacements, joint angles (manipulator configuration), and mass properties. Moreover, the coupling map was adopted and drawn to represent the coupling motion. Based on this map, a trajectory planning method was addressed to suppress structure vibration. Finally, simulation studies of typical cases were performed, which verified the proposed models and method. This work provides a theoretic basis for the system design, performance evaluation, trajectory planning, and control of such space robots.

  2. Hedgehog signaling patterns the outgrowth of unpaired skeletal appendages in zebrafish

    Directory of Open Access Journals (Sweden)

    Ahlberg Per

    2007-06-01

    Full Text Available Abstract Background Little is known about the control of the development of vertebrate unpaired appendages such as the caudal fin, one of the key morphological specializations of fishes. Recent analysis of lamprey and dogshark median fins suggests the co-option of some molecular mechanisms between paired and median in Chondrichthyes. However, the extent to which the molecular mechanisms patterning paired and median fins are shared remains unknown. Results Here we provide molecular description of the initial ontogeny of the median fins in zebrafish and present several independent lines of evidence that Sonic hedgehog signaling emanating from the embryonic midline is essential for establishment and outgrowth of the caudal fin primordium. However, gene expression analysis shows that the primordium of the adult caudal fin does not harbor a Sonic hedgehog-expressing domain equivalent to the Shh secreting zone of polarizing activity (ZPA of paired appendages. Conclusion Our results suggest that Hedgehog proteins can regulate skeletal appendage outgrowth independent of a ZPA and demonstrates an unexpected mechanism for mediating Shh signals in a median fin primordium. The median fins evolved before paired fins in early craniates, thus the patterning of the median fins may be an ancestral mechanism that controls the outgrowth of skeletogenic appendages in vertebrates.

  3. Knockdown of Parhyale Ultrabithorax recapitulates evolutionary changes in crustacean appendage morphology.

    Science.gov (United States)

    Liubicich, Danielle M; Serano, Julia M; Pavlopoulos, Anastasios; Kontarakis, Zacharias; Protas, Meredith E; Kwan, Elaine; Chatterjee, Sandip; Tran, Khoa D; Averof, Michalis; Patel, Nipam H

    2009-08-18

    Crustaceans possess remarkably diverse appendages, both between segments of a single individual as well as between species. Previous studies in a wide range of crustaceans have demonstrated a correlation between the anterior expression boundary of the homeotic (Hox) gene Ultrabithorax (Ubx) and the location and number of specialized thoracic feeding appendages, called maxillipeds. Given that Hox genes regulate regional identity in organisms as diverse as mice and flies, these observations in crustaceans led to the hypothesis that Ubx expression regulates the number of maxillipeds and that evolutionary changes in Ubx expression have generated various aspects of crustacean appendage diversity. Specifically, evolutionary changes in the expression boundary of Ubx have resulted in crustacean species with either 0, 1, 2, or 3 pairs of thoracic maxillipeds. Here we test this hypothesis by altering the expression of Ubx in Parhyale hawaiensis, a crustacean that normally possesses a single pair of maxillipeds. By reducing Ubx expression, we can generate Parhyale with additional maxillipeds in a pattern reminiscent of that seen in other crustacean species, and these morphological alterations are maintained as the animals molt and mature. These results provide critical evidence supporting the proposition that changes in Ubx expression have played a role in generating crustacean appendage diversity and lend general insights into the mechanisms of morphological evolution.

  4. Development of laser welded appendages to Zircaloy-4 fuel tubing (sheath/cladding)

    Energy Technology Data Exchange (ETDEWEB)

    Livingstone, S., E-mail: steve.livingstone@cnl.ca [Canadian Nuclear Laboratories Limited, Chalk River, ON, Canada K0J 1J0 (Canada); Xiao, L. [Canadian Nuclear Laboratories Limited, Chalk River, ON, Canada K0J 1J0 (Canada); Corcoran, E.C.; Ferrier, G.A.; Potter, K.N. [Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, ON, Canada K7K 7B4 (Canada)

    2015-04-01

    Highlights: • Examines feasibility of laser welding appendages to Zr-4 tubing. • Laser welding minimizes the HAZ and removes toxic Be. • Mechanical properties of laser welds appear competitive with induction brazed joints. • Work appears promising and lays the foundation for further investigations. - Abstract: Laser welding is a potential alternative to the induction brazing process commonly used for appendage attachment in CANDU{sup ®} fuel fabrication that uses toxic Be as a filler metal, and creates multiple large heat affected zones in the sheath. For this work, several appendages were laser welded to tubing using different laser heat input settings and then examined with a variety of techniques: visual examination, metallography, shear strength testing, impact testing, and fracture surface analysis. Where possible, the examination results are contrasted against production induction brazed joints. The work to date looks promising for laser welded appendages. Further work on joint optimization, corrosion testing, irradiation testing, and post-irradiation examination will be performed in the future.

  5. Air-flow sensitive hairs: boundary layers in oscillatory flows around arthropod appendages

    NARCIS (Netherlands)

    Steinmann, T.; Casas, J.; Krijnen, Gijsbertus J.M.; Dangles, O.

    2006-01-01

    The aim of this work is to characterize the boundary layer over small appendages in insects in longitudinal and transverse oscillatory flows. The problem of immediate interest is the early warning system in crickets perceiving flying predators using air-flow-sensitive hairs on cerci, two long

  6. Air-flow sensitive hairs: boundary layers in oscillatory flows around arthropod appendages

    NARCIS (Netherlands)

    Steinmann, T.; Casas, J.; Krijnen, G.J.M.; Dangles, O.

    2006-01-01

    The aim of this work is to characterize the boundary layer over small appendages in insects in longitudinal and transverse oscillatory flows. The problem of immediate interest is the early warning system in crickets perceiving flying predators using air-flow-sensitive hairs on cerci, two long append

  7. Epibulbar lipodermoids, preauricular appendages and polythelia in four generations: a new hereditary syndrome?

    DEFF Research Database (Denmark)

    Goldschmidt, Ernst; Jacobsen, Nina

    2010-01-01

    A new syndrome with abnormalities along the first branchial arch and the milk list is described in a family of four affected generations. The characteristics of the syndrome are epibulbar lipodermoids, preauricular appendages and polythelia. The expressivity varies but all affected have supernume...

  8. RELATION BETWEEN LEFT ATRIAL SIZE AND ATRIAL FIBRILLATION IN DIFFERENT DISEASES

    Directory of Open Access Journals (Sweden)

    Rajith

    2014-11-01

    Full Text Available BACKGROUND: Atrial fibrillation is the most common cardiac dysrhythmia and left atrial size is an important factor in the development of atrial fibrillation. In the presence of atrial fibrillation an increase in left atrial size is associated with increased risk of stroke as well as increased morbidity and mortality. In this context, this study entitled “relation between left atrial size and atrial fibrillation in different diseases” was undertaken to study the left atrial size in different diseases causing atrial fibrillation and its relation to the atrial fibrillation. METHODS: A cross-sectional study was done from March 2004 to February 2006 in all medical units of Basaveshwar teaching and general hospital and Government general hospital Gulbarga. 70 cases of atrial fibrillation were studied in the present study. RESULTS: In the present study Atrial Fibrillation was common in >40 years age group (70%, left atrial enlargement was also more common in this age group (69.38%. Left atrial enlargement was seen in 70% of patients with Atrial Fibrillation. Rheumatic heart disease was the most common cause of Atrial Fibrillation (54.28% and left atrial enlargement was seen in 92% of these patients with mean left atrial size of 58.92 mm. Next most common cause was coronary artery disease (20% and left atrial enlargement was seen in 57.14% patients with a mean left atrial size of 39.5 mm. Left atrial size was normal in patients with thyrotoxicosis, congenital heart disease, lone Atrial Fibrillation and primary pulmonary hypertension. Left atrial enlargement was significantly associated with worsening of functional status (p<0.01, pulmonary arterial hypertension (p<0.005 and congestive cardial failure (p<0.02. 17.14% of patients with Atrial Fibrillation had embolic complications like stroke, of them left atrial enlargement was seen in 83.33% patients. 4.27% of patients with Atrial Fibrillation died during the hospital course, of them left atrial

  9. Low atrial septum pacing in pacemaker patients

    NARCIS (Netherlands)

    Voogt, Willem Gijsbert de

    2006-01-01

    In patients with an indication for anti bradycardia pacing, atrial fibrillation (AF) is a common arrhythmia (30-50%) even in the absence of atrial tachy arrhythmias before pacemaker implantation. Pace prevention and pace intervention for atrial tachy arrhythmias could be an interesting adjuvant trea

  10. Low atrial septum pacing in pacemaker patients

    NARCIS (Netherlands)

    Voogt, Willem Gijsbert de

    2006-01-01

    In patients with an indication for anti bradycardia pacing, atrial fibrillation (AF) is a common arrhythmia (30-50%) even in the absence of atrial tachy arrhythmias before pacemaker implantation. Pace prevention and pace intervention for atrial tachy arrhythmias could be an interesting adjuvant

  11. Developing an ancient epithelial appendage: FGF signalling regulates early tail denticle formation in sharks.

    Science.gov (United States)

    Cooper, Rory L; Martin, Kyle J; Rasch, Liam J; Fraser, Gareth J

    2017-01-01

    Vertebrate epithelial appendages constitute a diverse group of organs that includes integumentary structures such as reptilian scales, avian feathers and mammalian hair. Recent studies have provided new evidence for the homology of integumentary organ development throughout amniotes, despite their disparate final morphologies. These structures develop from conserved molecular signalling centres, known as epithelial placodes. It is not yet certain whether this homology extends beyond the integumentary organs of amniotes, as there is a lack of knowledge regarding their development in basal vertebrates. As the ancient sister lineage of bony vertebrates, extant chondrichthyans are well suited to testing the phylogenetic depth of this homology. Elasmobranchs (sharks, skates and rays) possess hard, mineralised epithelial appendages called odontodes, which include teeth and dermal denticles (placoid scales). Odontodes constitute some of the oldest known vertebrate integumentary appendages, predating the origin of gnathostomes. Here, we used an emerging model shark (Scyliorhinus canicula) to test the hypothesis that denticles are homologous to other placode-derived amniote integumentary organs. To examine the conservation of putative gene regulatory network (GRN) member function, we undertook small molecule inhibition of fibroblast growth factor (FGF) signalling during caudal denticle formation. We show that during early caudal denticle morphogenesis, the shark expresses homologues of conserved developmental gene families, known to comprise a core GRN for early placode morphogenesis in amniotes. This includes conserved expression of FGFs, sonic hedgehog (shh) and bone morphogenetic protein 4 (bmp4). Additionally, we reveal that denticle placodes possess columnar epithelial cells with a reduced rate of proliferation, a conserved characteristic of amniote skin appendage development. Small molecule inhibition of FGF signalling revealed placode development is FGF dependent

  12. Nova abordagem técnica e eletrofisiológica para tratamento da fibrilação atrial New technical and eletrophysiological approach for atrial fibrillation treatment

    Directory of Open Access Journals (Sweden)

    Otoni Moreira Gomes

    2004-06-01

    controle ecocardiográfico. CONCLUSÃO: Pode-se concluir, como experiência inicial, que a abordagem eletrofisiológica e a técnica empregada otimizaram o tratamento cirúrgico da fibrilação atrial, possibilitando a correção de lesões valvares mitrais e tricúspide sem morbidade adicional.INTRODUCTION: The maze procedure for primary atrial fibrillation treatment, initially proposed by Cox, is somewhat complex and increases the morbidity risk originating from the isolated mitral valve surgery itself. OBJECTIVE: To describe the surgical technique, the concepts of electrophysiology considered and the initial results of a new surgical and electrophysiological approach. Also the blocking of main atrial circuits as defined by Frame and optimization of the surgical tactic for atrial fibrillation treatment are considered. METHOD: Eight patients with chronic atrial fibrillation and mitral valve dysfunction and with tricuspid valve regurgitation in one case were operated on. The following modifications of the classic Cox procedure were employed: 1. - Exclusion of the left atrium appendage by internal suturing to close its left atrial ostium; 2. - Exclusion of the right atrium appendage by one purse string suture used for the fixation of the superior vena cava draining cannula; 3. - Single atrial incision; 4. - Transendocardial electrocauterization of the left atrium wall around all the pulmonary vein ostia; 5. - Substitution of the incisions and sutures in the left atrium by transendocardial electrocauterization. RESULTS: The cardiopulmonary bypass time varied from 64 to 133 min (mean 107.5 min and the cardioplegia time was from 40 to 105 min. (mean 76.7 min. At the end of the surgery all patients were in regular atrial rhythm. The postoperative period was uneventful with all patients discharged from hospital showing regular atrial rhythm, without definitive pacemaker implantation. Six months after surgery, six patients were in regular atrial rhythm (75% with preserved atrial

  13. Oxidative stress and inflammation as central mediators of atrial fibrillation in obesity and diabetes.

    Science.gov (United States)

    Karam, Basil S; Chavez-Moreno, Alejandro; Koh, Wonjoon; Akar, Joseph G; Akar, Fadi G

    2017-09-29

    Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in humans. Several risk factors promote AF, among which diabetes mellitus has emerged as one of the most important. The growing recognition that obesity, diabetes and AF are closely intertwined disorders has spurred major interest in uncovering their mechanistic links. In this article we provide an update on the growing evidence linking oxidative stress and inflammation to adverse atrial structural and electrical remodeling that leads to the onset and maintenance of AF in the diabetic heart. We then discuss several therapeutic strategies to improve atrial excitability by targeting pathways that control oxidative stress and inflammation.

  14. Substrate-specific derangements in mitochondrial metabolism and redox balance in the atrium of the type 2 diabetic human heart.

    Science.gov (United States)

    Anderson, Ethan J; Kypson, Alan P; Rodriguez, Evelio; Anderson, Curtis A; Lehr, Eric J; Neufer, P Darrell

    2009-11-10

    The aim of this study was to determine the impact of diabetes on oxidant balance and mitochondrial metabolism of carbohydrate- and lipid-based substrates in myocardium of type 2 diabetic patients. Heart failure represents a major cause of death among diabetic patients. It has been proposed that derangements in cardiac metabolism and oxidative stress may underlie the progression of this comorbidity, but scarce evidence exists in support of this mechanism in humans. Mitochondrial oxygen (O(2)) consumption and hydrogen peroxide (H(2)O(2)) emission were measured in permeabilized myofibers prepared from samples of the right atrial appendage obtained from nondiabetic (n = 13) and diabetic (n = 11) patients undergoing nonemergent coronary artery bypass graft surgery. Mitochondria in atrial tissue of type 2 diabetic individuals show a sharply decreased capacity for glutamate and fatty acid-supported respiration, in addition to an increased content of myocardial triglycerides, as compared to nondiabetic patients. Furthermore, diabetic patients show an increased mitochondrial H(2)O(2) emission during oxidation of carbohydrate- and lipid-based substrates, depleted glutathione, and evidence of persistent oxidative stress in their atrial tissue. These findings are the first to directly investigate the effects of type 2 diabetes on a panoply of mitochondrial functions in the human myocardium using cellular and molecular approaches, and they show that mitochondria in diabetic human hearts have specific impairments in maximal capacity to oxidize fatty acids and glutamate, yet increased mitochondrial H(2)O(2) emission, providing insight into the role of mitochondrial dysfunction and oxidative stress in the pathogenesis of heart failure in diabetic patients. 2009 by the American College of Cardiology Foundation

  15. Substrate-Specific Derangements in Mitochondrial Metabolism and Redox Balance in Atrium of Type 2 Diabetic Human Heart

    Science.gov (United States)

    Anderson, Ethan J.; Kypson, Alan P.; Rodriguez, Evelio; Anderson, Curtis A.; Lehr, Eric J.; Neufer, P. Darrell

    2009-01-01

    Objective This aim of this study was to determine the impact of diabetes on oxidant balance and mitochondrial metabolism of carbohydrate- and lipid-based substrates in myocardium of type 2 diabetic patients. Background Heart failure represents a major cause of death among diabetics, and it has been proposed that derangements in cardiac metabolism and oxidative stress may underlie the progression of this co-morbidity, but scarce evidence exists in support of this mechanism in humans. Methods Mitochondrial O2 consumption and H2O2 emission were measured in permeabilized myofibers prepared from samples of right atrial appendage obtained from non-diabetic (n=13) and diabetic (n=11) patients undergoing non-emergent coronary artery bypass graft surgery. Results Mitochondria in atrial tissue of type 2 diabetic individuals display a sharply decreased capacity for glutamate and fatty acid-supported respiration, in addition to an increased content of myocardial triglycerides, as compared to non-diabetics. Furthermore, diabetics display an increased mitochondrial H2O2 emission during oxidation of carbohydrate- and lipid-based substrates, depleted glutathione, and evidence of persistent oxidative stress in their atrial tissue. Conclusions These findings are the first to directly investigate the effects of type 2 diabetes on a panoply of mitochondrial functions in the human myocardium using cellular and molecular approaches, and they demonstrate that mitochondria in diabetic human heart have specific impairments in maximal capacity to oxidize fatty acids and glutamate, yet increased mitochondrial H2O2 emission, providing insight into the role of mitochondrial dysfunction and oxidative stress in the pathogenesis of heart failure in diabetic patients. PMID:19892241

  16. Total plasma proANP increases with atrial dilatation in horses.

    Science.gov (United States)

    Van Der Vekens, N; Hunter, I; Timm, A; Decloedt, A; De Clercq, D; Deprez, P; Goetze, J P; van Loon, G

    2015-12-19

    Equine atrial natriuretic peptide (ANP) plasma concentrations are correlated with left atrial size. However, species-specific assays are lacking and the results from human assays are poorly reproducible. A new methodology called processing independent analysis (PIA) that measures the total proANP product in plasma has proven to be successful in human medicine, but has never been used in horses. The aims were to establish an equine proANP reference interval by measurement of the total proANP product using PIA and to examine the proANP concentrations in horses with atrial dilatation. Sample stability was studied by comparison of storage at -80°C and -20°C. Plasma samples were obtained from 23 healthy horses, 12 horses with moderate or severe valvular regurgitation without atrial dilatation and 42 horses with valvular regurgitation and atrial dilatation. The proANP concentration was significantly (Phorses with atrial dilatation (761.4 (442.1-1859.1) pmol/l) than in healthy horses (491.6 (429.5-765.9) pmol/l; Phorses with cardiac disease but without atrial dilatation (544.4 (457.0-677.6) pmol/l). A cut-off value (573.8 pmol/l) for detection of atrial dilatation was calculated. Sample storage at -80°C did not differ from sample storage at -20°C. The measurement of total proANP in plasma detects atrial dilatation in horses and may be useful for clinical evaluation in equine medicine.

  17. Atrial fibrillation and delayed gastric emptying.

    Directory of Open Access Journals (Sweden)

    Isadora C Botwinick

    Full Text Available BACKGROUND: Atrial fibrillation and delayed gastric emptying (DGE are common after pancreaticoduodenectomy. Our aim was to investigate a potential relationship between atrial fibrillation and DGE, which we defined as failure to tolerate a regular diet by the 7(th postoperative day. METHODS: We performed a retrospective chart review of 249 patients who underwent pancreaticoduodenectomy at our institution between 2000 and 2009. Data was analyzed with Fisher exact test for categorical variables and Mann-Whitney U or unpaired T-test for continuous variables. RESULTS: Approximately 5% of the 249 patients included in the analysis experienced at least one episode of postoperative atrial fibrillation. Median age of patients with atrial fibrillation was 74 years, compared with 66 years in patients without atrial fibrillation (p = 0.0005. Patients with atrial fibrillation were more likely to have a history of atrial fibrillation (p = 0.03. 92% of the patients with atrial fibrillation suffered from DGE, compared to 46% of patients without atrial fibrillation (p = 0.0007. This association held true when controlling for age. CONCLUSION: Patients with postoperative atrial fibrillation are more likely to experience delayed gastric emptying. Interventions to manage delayed gastric function might be prudent in patients at high risk for postoperative atrial fibrillation.

  18. Serum atrial natriuretic peptide (ANP) as an objective indicator for the diagnosis of neurogenic shock: animal experiment and human case report.

    Science.gov (United States)

    Zhao, Min-Zhu; Li, Yong-Guo; Zhang, Peng; Xiong, Jin-Cheng; Zhu, Shi-Sheng; Xiao, Xuan; Li, Jian-Bo

    2017-03-01

    In forensic medicine, the diagnosis of death due to neurogenic shock is considered to be an aporia, as lacking objective indicators and presenting atypical symptoms in autopsy. Medico-legal disputes and complaints occasionally result from this ambiguity. To explore potential objective indicators of neurogenic shock, we set up a model of neurogenic shock by applying an external mechanical force on the carotid sinus baroreceptor in rabbits. The serum atrial natriuretic peptide (ANP) level was measured by radioimmunoassay in the control group (n = 8), survival group (n = 15) and death group (n = 5) both before and after the insult. The serum ANP level showed a significant increase after the insult in the death group compared with the serum obtained before the insult (P = 0.006), while the serum ANP level after the insult in the survival group and control group was not statistically significant compared with the serum obtained before the insult (P = 0.332 and P = 0.492, respectively). To verify the repeatability of the model and the postmortem behavior of serum ANP, five healthy adult rabbits underwent the same procedure as the experimental group. The mortality rate was consistent with the former experiment (20 %). There were no significant changes in serum ANP level in vitro and in vivo (within 48 and 24 h, respectively). But there was a significant decrease in serum ANP level at 48 h postmortem in vivo (P = 0.001). A female patient who expired due to neurogenic shock during a hysteroscopy was reported. Neither fatal primary disease nor evidence for mechanical injuries or intoxication was found according to the autopsy. The serum ANP level was assayed as a supplementary indicator and was found to be three-fold higher than the normal maximum limit. Combined with the animal experiment, this case highlights that serum ANP has the potential to be an objective indicator for the diagnosis of death due to neurogenic shock.

  19. Formation of body appendages during caudal regeneration in Platynereis dumerilii: adaptation of conserved molecular toolsets

    Directory of Open Access Journals (Sweden)

    Jan Grimmel

    2016-04-01

    Full Text Available Abstract Background Platynereis and other polychaete annelids with homonomous segmentation are regarded to closely resemble ancestral forms of bilateria. The head region comprises the prostomium, the peristomium, a variable number of cephalized body segments and several appendages, like cirri, antennae and palps. The trunk of such polychaetes shows numerous, nearly identical segments. Each segment bears a parapodium with species-specific morphology on either side. The posterior end of the trunk features a segment proliferation zone and a terminal pygidium with the anus and anal cirri. The removal of a substantial part of the posterior trunk is by no means lethal. Cells at the site of injury dedifferentiate and proliferate forming a blastema to regenerate both the pygidium and the proliferation zone. The pygidium forms new anal cirri, and the proliferation zone generates new segments at a rapid pace. The formation of body appendages like the cirri and the segmental parapodia can thus be studied in the caudal regenerate of Platynereis within only a few days. Results The development of body appendages in Platynereis is regulated by a network of genes common to polychaetes but also shared by distant taxa. We isolated DNA sequences from P. dumerilii of five genes known to be involved in appendage formation within other groups: Meis/homothorax, Pbx1/extradenticle, Dlx/Distal-less, decapentaplegic and specific protein 1/buttonhead. Analyses of expression patterns during caudal regeneration by in situ hybridization reveal striking similarities related to expression in arthropods and vertebrates. All genes exhibit transient expression during differentiation and growth of segments. As was shown previously in other phyla Pdu-Meis/hth and Pdu-Pbx1/exd are co-expressed, although the expression is not limited to the proximal part of the parapodia. Pdu-Dll is prominent in parapodia but upregulated in the anal cirri. No direct dependence concerning Pdu-Dll and

  20. [New antithrombotics for atrial fibrillation].

    NARCIS (Netherlands)

    Verheugt, F.W.A.

    2011-01-01

    Cerebral infarction is the most serious complication of atrial fibrillation. Coumarin derivatives (vitamin K antagonists) counteract systemic thromboembolism and reduce the risk of stroke by more than 60%, but carry a risk of serious bleeding. Antiplatelet therapy and subcutaneous low-molecular-weig

  1. Radiofrequency ablation of atrial fibrillation

    NARCIS (Netherlands)

    Wiesfeld, ACP; Tan, ES; Van Veldhuisen, DJ; Crijns, HJGM; Van Gelder, IC

    2004-01-01

    Twenty-five patients (16 males, mean age 46 years.) underwent radiofrequency ablation because of either paroxysmal (13 patients) or persistent atrial fibrillation (12 patients). Ablation aimed at earliest activation of spontaneous and catheter-induced repetitive ectopy in left and right atria and ap

  2. Genetic basis of atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Oscar Campuzano

    2016-12-01

    Full Text Available Atrial fibrillation is the most common sustained arrhythmia and remains as one of main challenges in current clinical practice. The disease may be induced secondary to other diseases such as hypertension, valvular heart disease, and heart failure, conferring an increased risk of stroke and sudden death. Epidemiological studies have provided evidence that genetic factors play an important role and up to 30% of clinically diagnosed patients may have a family history of atrial fibrillation. To date, several rare variants have been identified in a wide range of genes associated with ionic channels, calcium handling protein, fibrosis, conduction and inflammation. Important advances in clinical, genetic and molecular basis have been performed over the last decade, improving diagnosis and treatment. However, the genetics of atrial fibrillation is complex and pathophysiological data remains still unraveling. A better understanding of the genetic basis will induce accurate risk stratification and personalized clinical treatment. In this review, we have focused on current genetics basis of atrial fibrillation.

  3. Facts about Atrial Septal Defect

    Science.gov (United States)

    ... Living With Heart Defects Data & Statistics Tracking & Research Articles & Key Findings Free Materials Multimedia and Tools Links to Other Websites Information For... Media Policy Makers Facts about Atrial Septal Defect Language: English Español (Spanish) Recommend on Facebook Tweet Share Compartir ...

  4. Personalized management of atrial fibrillation

    DEFF Research Database (Denmark)

    Kirchhof, Paulus; Breithardt, Günter; Aliot, Etienne

    2013-01-01

    The management of atrial fibrillation (AF) has seen marked changes in past years, with the introduction of new oral anticoagulants, new antiarrhythmic drugs, and the emergence of catheter ablation as a common intervention for rhythm control. Furthermore, new technologies enhance our ability to de...

  5. Acupuncture Antiarrhythmic Effects on Drug Refractory Persistent Atrial Fibrillation: Study Protocol for a Randomized, Controlled Trial

    Directory of Open Access Journals (Sweden)

    Jimin Park

    2015-01-01

    Full Text Available Background. Atrial fibrillation (AF is the most common form of arrhythmia. Several trials have suggested that acupuncture may prevent AF. However, the efficacy of acupuncture for AF prevention has not been well investigated. Therefore, we designed a prospective, two-parallel-armed, participant and assessor blinded, randomized, sham-controlled clinical trial to investigate acupuncture in persistent AF (ACU-AF. Methods. A total of 80 participants will be randomly assigned to active acupuncture or sham acupuncture groups in a 1 : 1 ratio. Both groups will take the same antiarrhythmic medication during the study period. Patients will receive 10 sessions of acupuncture treatment once a week for 10 weeks. The primary endpoint is AF recurrence rate. Secondary endpoints are left atrium (LA and left atrial appendage (LAA changes in function and volume, and inflammatory biomarker changes. Ethics. This study protocol was approved by the institutional review boards (IRBs of Kyung Hee University Hospital (number 1335-04. This trial is registered with clinicaltrials.gov NCT02110537.

  6. Novel nonpharmacologic approaches for stroke prevention in atrial fibrillation: results from clinical trials

    Science.gov (United States)

    Proietti, Riccardo; Joza, Jacqueline; Arensi, Andrea; Levi, Michael; Russo, Vincenzo; Tzikas, Apostolos; Danna, Paolo; Sagone, Antonio; Viecca, Maurizio; Essebag, Vidal

    2015-01-01

    Atrial fibrillation (AF), the most common cardiac arrhythmia, confers a 5-fold risk of stroke that increases to 17-fold when associated with mitral stenosis. At this time, the most effective long-term solution to protect patients from stroke and thromboembolism is oral anticoagulation, either with vitamin K antagonists (VKAs) or a novel oral anticoagulant (NOAC). Despite the significant benefits they confer, both VKAs and NOACs are underused because of their increased potential for bleeding, and VKAs are underused because of their narrow therapeutic range, need for regular international normalized ratio checks, and interactions with food or medications. In patients with nonvalvular AF, approximately 90% of strokes originate from the left atrial appendage (LAA); in patients with rheumatic mitral valve disease, many patients (60%) have strokes that originate from the left atrium itself. Surgical LAA amputation or closure, although widely used to reduce stroke risk in association with cardiac surgery, is not currently performed as a stand-alone operation for stroke risk reduction because of its invasiveness. Percutaneous LAA closure, as an alternative to anticoagulation, has been increasingly used during the last decade in an effort to reduce stroke risk in nonvalvular AF. Several devices have been introduced during this time, of which one has demonstrated noninferiority compared with warfarin in a randomized controlled trial. This review describes the available technologies for percutaneous LAA closure, as well as a summary of the published trials concerning their safety and efficacy in reducing stroke risk in AF. PMID:25678828

  7. Ultrasonographic diagnosis of torsion of testicular appendages; Diagnostico por ecografia de la torsion de los apendices testiculares

    Energy Technology Data Exchange (ETDEWEB)

    Esparza, J.; Gonzalez, A.; Cordero, J. L. [Hospital Virgen del Camino. Pamplona (Spain)

    2000-07-01

    To determine the efficacy of ultrasound in boys presenting torsion of a testicular appendage. A series of 30 boys with acute scrotal pain due to torsion of a testicular appendage was studied. Nine patients underwent surgery. The clinical findings and course in the remaining 21 suggested the presence of this abnormality. All of them underwent conventional and color Doppler ultrasound using a 7.5 MHz transducer. In 15 boys, ultrasound images depicted the affected appendage as a mass between the epididymal head and the testicle. In 13 cases, only signs of a inflammatory reaction, with enlargement of the epididymal head and tunicas presenting hyperflow and hydrocele, mimicking acute epididymities. In two cases, the images were normal. There is no definitive, distinguishing ultrasound image corresponding to testicular appendage torsion. Therefore, this diagnostic technique should be accompanied by clinical assessment. (Author) 14 refs.

  8. [Atrial fibrillation and cognitive function].

    Science.gov (United States)

    Duron, Emmanuelle; Hanon, Olivier

    2010-09-01

    Atrial fibrillation (AF), which prevalence increases with age, is a growing public health problem and a well known risk factor for stroke. On the other hand, dementia is one of the most important neurological disorders in the elderly, and with aging of the population in developed countries, the number of demented patients will increase in absence of prevention. In the past decade, several vascular risk factors (hypertension, obesity and metabolic syndrome, hypercholesterolemia) have been found, with various degree of evidence, to be associated with vascular dementia but also, surprisingly, with Alzheimer's disease. This review is devoted to the links between atrial fibrillation, cognitive decline and dementia. Globally, transversal studies showed a significant association between atrial fibrillation, cognitive decline and dementia. However, these studies are particularly sensitive to various biases. In this context, recent longitudinal studies of higher level of evidence have been conducted to assess the link between AF and dementia. One study disclosed a high incidence of dementia among patients suffering from atrial fibrillation during a 4.6 years follow-up. Similarly another study showed that atrial fibrillation was significantly associated with conversion from mild cognitive impairment to dementia during a 3 years follow-up. Nevertheless two other longitudinal studies did not find any significant association between AF and dementia, but this discrepancy should be interpreted taking into account that the comparability of all these studies is moderate because they were using different methodologies (population, cognitive testing, and mean follow-up). Possible explanatory mechanisms for the association between AF and the risk of dementia are proposed, such as thrombo-embolic ischemic damage and cerebral hypo perfusion due to fluctuations in the cardiac output. Thus, there is some evidence that FA could be associated with cognitive decline and dementia but this

  9. Cephalic and appendage morphology of the Cambrian arthropod Sidneyia inexpectans Walcott, 1911

    DEFF Research Database (Denmark)

    Stein, Martin

    2013-01-01

    as an evidence for variability of head segment counts in Cambrian arthropods, and to falsify the hypothesis of a head with three postantennular segments in the euarthropod ground pattern. Restudy of a substantial amount of material of S. inexpectans shows that previous interpretations of a short head were based...... understood, but the exopod seemed to differ from that of other artiopodans, except for the shared presence of lamellae. The head was considered to comprise only the ocular and antennular segments, these being covered entirely on the ventral side by a large doublure. This short head was often taken...... postantennular appendage bearing segments. The appendage morphology is shown to be consistent with artiopodan affinities. The exopod is of the bilobate flap-like type with lamellae inserting on the proximal portion, earlier proposed as a potential autapomorphy of Artiopoda. Reinforcement of artiopodan affinities...

  10. emc has a role in dorsal appendage fate formation in Drosophila oogenesis.

    Science.gov (United States)

    Papadia, Sofia; Tzolovsky, George; Zhao, Debiao; Leaper, Kevin; Clyde, Dorothy; Taylor, Paul; Asscher, Eva; Kirk, Graeme; Bownes, Mary

    2005-09-01

    extramacrochaetae (emc) functions during many developmental processes in Drosophila, such as sensory organ formation, sex determination, wing vein differentiation, regulation of eye photoreceptor differentiation, cell proliferation and development of the Malpighian tubules, trachea and muscles in the embryo. It encodes a Helix-Loop-Helix transcription factor that negatively regulates bHLH proteins. We show here that emc mRNA and protein are present throughout oogenesis in a dynamic expression pattern and that emc is involved in the regulation of chorionic appendage formation during late oogenesis. Expression of sense and antisense emc constructs as well as emc follicle cell clones leads to eggs with shorter, thicker dorsal appendages that are closer together at base than in the wild type. We demonstrate that emc lies downstream of fs(1)K10, gurken and EGFR in the Grk/EGFR signalling pathway and that it participates in controlling Broad-Complex expression at late stages of oogenesis.

  11. The integumental appendages of the turtle shell: an evo-devo perspective.

    Science.gov (United States)

    Moustakas-Verho, Jacqueline E; Cherepanov, Gennadii O

    2015-05-01

    The turtle shell is composed of dorsal armor (carapace) and ventral armor (plastron) covered by a keratinized epithelium. There are two epithelial appendages of the turtle shell: scutes (large epidermal shields separated by furrows and forming a unique mosaic) and tubercles (numerous small epidermal bumps located on the carapaces of some species). In our perspective, we take a synthetic, comparative approach to consider the homology and evolution of these integumental appendages. Scutes have been more intensively studied, as they are autapomorphic for turtles and can be diagnostic taxonomically. Their pattern of tessellation is stable phylogenetically, but labile in the individual. We discuss the history of developmental investigations of these structures and hypotheses of evolutionary and anomalous variation. In our estimation, the scutes of the turtle shell are an evolutionary novelty, whereas the tubercles found on the shells of some turtles are homologous to reptilian scales. © 2015 Wiley Periodicals, Inc.

  12. MARCKS-like protein is an initiating molecule in axolotl appendage regeneration.

    Science.gov (United States)

    Sugiura, Takuji; Wang, Heng; Barsacchi, Rico; Simon, Andras; Tanaka, Elly M

    2016-03-10

    Identifying key molecules that launch regeneration has been a long-sought goal. Multiple regenerative animals show an initial wound-associated proliferative response that transits into sustained proliferation if a considerable portion of the body part has been removed. In the axolotl, appendage amputation initiates a round of wound-associated cell cycle induction followed by continued proliferation that is dependent on nerve-derived signals. A wound-associated molecule that triggers the initial proliferative response to launch regeneration has remained obscure. Here, using an expression cloning strategy followed by in vivo gain- and loss-of-function assays, we identified axolotl MARCKS-like protein (MLP) as an extracellularly released factor that induces the initial cell cycle response during axolotl appendage regeneration. The identification of a regeneration-initiating molecule opens the possibility of understanding how to elicit regeneration in other animals.

  13. Epiploic appendagitis of caecum: a diagnostic dilemma [Appendicitis epiploica des Blinddarms: ein diagnostisches Dilemma

    Directory of Open Access Journals (Sweden)

    Rashid, Arshad

    2012-10-01

    Full Text Available [english] Epiploic appendagitis is a rare cause of acute abdomen. Depending on the site of occurrence, it can mimic any cause of acute abdomen or disease of the colon and caecal appendix; making its preoperative diagnosis very difficult. We present here a case of a 7-year-old boy misdiagnosed preoperatively as acute appendicitis and later on, upon surgical exploration, found to have caecal appendagitis. The affected epiploic appendage was removed and the patient had an uneventful recovery. We also review the relevant literature and discuss the measures to overcome this diagnostic dilemma. General surgeons should be aware of this self-limiting disease and consider it as a differential diagnosis of acute abdomen.[german] Appendicitis epiploica oder epiploische Appendagitis ist eine seltene Ursache des akuten Abdomens. Je nach Ort des Auftretens kann sie jede Ursache für akuten Unterleibsschmerz oder Erkrankungen des Dickdarms und Appendix vermiformis imitieren, was ihre präoperative Diagnose sehr schwierig macht. Wir präsentieren hier den Fall eines alten Jungen, bei dem präoperativ akute Blinddarmentzündung diagnostiziert wurde. Beim chirurgischen Eingriff stellte sich dann eine Appendicitis epiploica des Blinddarms als Befund heraus. Der betroffene Appendix epiploica wurde entfernt und der Patient erholte sich ohne besondere Vorkommnisse. Wir geben auch eine Übersicht über die relevante Literatur und diskutieren die Maßnahmen, um dieses diagnostische Dilemma zu überwinden. Allgemeine Chirurgen sollten sich dieser selbstlimitierenden Krankheit bewusst sein und sie als eine Differentialdiagnose bei akutem Abdomen in Betracht ziehen.

  14. Pallister-Killian syndrome: additional manifestations of cleft palate and sacral appendage.

    OpenAIRE

    McLeod, D R; Wesselman, L R; Hoar, D I

    1991-01-01

    We report a case of Pallister-Killian syndrome in a 28 week gestation infant. In addition to the characteristic phenotype, this patient had a cleft palate, diaphragmatic hernia, sacral appendage, and imperforate anus. The lymphocyte karyotype showed 96% 46,XX/4% 47,XX+i (12p) and the fibroblast karyotype 47,XX,+marker (presumed i(12p]. Fibroblast cytogenetic studies should be considered in all cases of diaphragmatic hernia associated with other malformations.

  15. MARCKS-Like Protein is an Initiating Molecule in Axolotl Appendage Regeneration

    OpenAIRE

    Sugiura, Takuji; Wang, Heng; Barsacchi, Rico; Simon, Andras; Tanaka, Elly M.

    2016-01-01

    Identifying key molecules that launch regeneration has been a long sought goal. Multiple regenerative animals show an initial wound-associated proliferative response that transits into sustained proliferation if a significant portion of the body part has been removed 1-3 . In the axolotl, appendage amputation initiates a round of wound-associated cell cycle induction followed by continued proliferation that is dependent on nerve-derived signals 4,5 . A wound-associated molecule that triggers ...

  16. Acute epiploic appendagitis: A rare cause of acute abdomen and a diagnostic dilemma

    Directory of Open Access Journals (Sweden)

    Afnan F Almuhanna

    2016-01-01

    Full Text Available Acute epiploic appendagitis is a relatively rare cause of lower abdominal pain that clinically mimics other acute abdomen conditions that require surgery such as acute diverticulitis or appendicitis. Here, we report a case of a 50-year-old lady who presented with an unusual lower abdominal pain. Awareness of such a clinical condition with its characteristic imaging findings is important to avoid costly hospitalization, unnecessary antibiotic courses, and the morbidity and mortality associated with surgical procedures.

  17. Functional similarity in appendage specification by the Ultrabithorax and abdominal-A Drosophila HOX genes.

    OpenAIRE

    Casares, F.; Calleja, M.; Sánchez-Herrero, E

    1996-01-01

    In Drosophila, the Ultrabithorax, abdominal-A and Abdominal-B HOX genes of the bithorax complex determine the identity of part of the thorax and the whole abdomen. Either the absence of these genes or their ectopic expression transform segments into the identity of different ones along the antero-posterior axis. Here we show that misexpression of Ultrabithorax, abdominal-A and, to some extent, Abdominal-B genes cause similar transformations in some of the fruitfly appendages: antennal tissue ...

  18. Adaptação de um sistema de ensaio biológico para detecção de fatores relaxantes endoteliais derivados do endocárdio atrial canino Adaptation of bioassay to detect endothelium-derived relaxing factors from the canine atrial endocardium

    Directory of Open Access Journals (Sweden)

    Yeow Leng Chua

    2009-06-01

    Full Text Available OBJETIVO: Estudar a liberação de fatores relaxantes derivados do endotélio (EDRF pelo endocárdio de aurículas de corações caninos. MÉTODOS: Aurículas atriais caninas foram suturadas em forma de tubos e o efluente desses tubos foram submetidos a ensaios biológicos (sistema de perfusão isolada em câmaras de órgãos utilizando artéria coronária canina, para a detecção de EDRFs. RESULTADOS: O efluente da aurícula direita promoveu relaxamento de 58,4 + 10,1% e da aurícula esquerda 74,9 + 8,5% da contração inicial obtida pela ação da prostagladina F2α em artéria coronária. Não houve diferença estatística no relaxamento da artéria coronária induzido pelos efluentes das aurículas direita e esquerda. O relaxamento induzido pelos efluentes das aurículas direita e esquerda foi abolido pelo tratamento das mesmas com Triton X-100. O tratamento das aurículas com L-NMMA, um inibidor competitivo da síntese de óxido nítrico, e com indometacina, um inibidor da via da ciclooxigenase, promoveu redução no relaxamento da artéria coronária induzido pelo efluente auricular, indicando que o endotélio endocárdico libera óxido nítrico e prostanóides. CONCLUSÕES: Esse estudo demonstra, pela primeira vez, a liberação luminal in vitro de EDRF e prostaciclina pelo átrio de coração canino. A habilidade do endotélio endocárdico em produzir esses fatores pode ter um papel importante na prevenção da formação de trombos nas câmaras cardíacas.OBJECTIVE: The aim of this study was to assess the release of endothelium-derived relaxing factors from the endocardium of canine atrial appendage. METHODS: To study the release of endothelium-derived relaxing factor (EDRF from intact atrial endocardial endothelium, tube-shaped sutures of canine atrial appendages were performed and effluents from these tubes were bioassayed (isolated perfused organ chamber system for detection of EDRF in canine coronary artery. RESULTS: Effluent from

  19. Advanced CFD simulations of turbulent flows around appendages in CANDU fuel bundles

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, F.; Hadaller, G.I.; Fortman, R.A., E-mail: fabbasian@sternlab.com [Stern Laboratories Inc., Hamilton, Ontario (Canada)

    2013-07-01

    Computational Fluid Dynamics (CFD) was used to simulate the coolant flow in a modified 37-element CANDU fuel bundle, in order to investigate the effects of the appendages on the flow field. First, a subchannel model was created to qualitatively analyze the capabilities of different turbulence models such as k.ε, Reynolds Normalization Group (RNG), Shear Stress Transport (SST) and Large Eddy Simulation (LES). Then, the turbulence model with the acceptable quality was used to investigate the effects of positioning appendages, normally used in CANDU 37-element Critical Heat Flux (CHF) experiments, on the flow field. It was concluded that the RNG and SST models both show improvements over the k.ε method by predicting cross flow rates closer to those predicted by the LES model. Also the turbulence effects in the k.ε model dissipate quickly downstream of the appendages, while in the RNG and SST models appear at longer distances similar to the LES model. The RNG method simulation time was relatively feasible and as a result was chosen for the bundle model simulations. In the bundle model simulations it was shown that the tunnel spacers and leaf springs, used to position the bundles inside the pressure tubes in the experiments, have no measureable dominant effects on the flow field. The flow disturbances are localized and disappear at relatively short streamwise distances. (author)

  20. Improbable appendages: Deer antler renewal as a unique case of mammalian regeneration.

    Science.gov (United States)

    Kierdorf, Uwe; Li, Chunyi; Price, Joanna S

    2009-07-01

    Deer antlers are periodically replaced cranial appendages that develop from permanent outgrowths of the frontal bones known as pedicles. Antler re-growth is a unique regenerative event in mammals which in general are unable to replace bony appendages. Recent evidence suggests that antler regeneration is a stem cell-based process that depends on the activation of stem cells located in the pedicle periosteum which are presumed to be neural crest-derived. It has been demonstrated that several developmental pathways are involved in antler regeneration that are also known to play a role in the control of skeletal development and regeneration in other vertebrates. However, in contrast to most other natural examples of regeneration of complete body structures, antler regeneration apparently neither depends on a functional nerve supply nor involves a direct contact between wound epithelium and mesenchymal tissue. Antlers thus demonstrate that regeneration of a large bony appendage in a mammal can be achieved by a process that differs in certain aspects from epimorphic regeneration in lower vertebrates.

  1. Regulatory evolution of Tbx5 and the origin of paired appendages.

    Science.gov (United States)

    Adachi, Noritaka; Robinson, Molly; Goolsbee, Aden; Shubin, Neil H

    2016-09-01

    The diversification of paired appendages has been a major factor in the evolutionary radiation of vertebrates. Despite its importance, an understanding of the origin of paired appendages has remained elusive. To address this problem, we focused on T-box transcription factor 5 (Tbx5), a gene indispensable for pectoral appendage initiation and development. Comparison of gene expression in jawless and jawed vertebrates reveals that the Tbx5 expression in jawed vertebrates is derived in having an expression domain that extends caudal to the heart and gills. Chromatin profiling, phylogenetic footprinting, and functional assays enabled the identification of a Tbx5 fin enhancer associated with this apomorphic pattern of expression. Comparative functional analysis of reporter constructs reveals that this enhancer activity is evolutionarily conserved among jawed vertebrates and is able to rescue the finless phenotype of tbx5a mutant zebrafish. Taking paleontological evidence of early vertebrates into account, our results suggest that the gain of apomorphic patterns of Tbx5 expression and regulation likely contributed to the morphological transition from a finless to finned condition at the base of the vertebrate lineage.

  2. Atrioverter : An implantable device for the treatment of atrial fibrillation

    NARCIS (Netherlands)

    Wellens, HJJ; Lau, CP; Luderitz, B; Akhtar, M; Waldo, AL; Camm, AJ; Timmermans, C; Tse, HF; Jung, W; Jordaens, L; Ayers, G

    1998-01-01

    Background-During atrial fibrillation, electrophysiological changes occur in atrial tissue that favor the maintenance of the arrhythmia and facilitate recurrence after conversion to sinus rhythm. An implantable defibrillator connected to right atrial and coronary sinus defibrillation leads allows pr

  3. Left Atrial Tachycardia After Pulmonary Vein Isolation for Atrial Fibrillation

    Directory of Open Access Journals (Sweden)

    Kenichi Hashimoto, MD

    2005-01-01

    Full Text Available Left atrial tachycardia (AT has been reported to occur after pulmonary vein isolation (PVI for the treatment of atrial fibrillation (AF. We treated 3 patients who developed AT of different mechanisms following PVI. In case 1, focal AT originating at the ostium of the left superior PV was demonstrated and focal radiofrequency ablation was performed at the breakthrough point at the ostium of the left superior PV terminated the AT. In case 2, AT was shown to be counterclockwise macroreentrant AT around the left inferior PV through the conduction gap of the left sided posterior wall for which linear ablation was performed between left superior and inferior PVs. Focal ablation at the conduction gap terminated the AT. In case 3, a macroreentrant AT propagating around the mitral annulus was demonstrated and linear ablation between left inferior pulmonary vein and mitral annulus (mitral isthmus terminated the AT.

  4. Epidermal hyperplasia and appendage abnormalities in mice lacking CD109.

    Science.gov (United States)

    Mii, Shinji; Murakumo, Yoshiki; Asai, Naoya; Jijiwa, Mayumi; Hagiwara, Sumitaka; Kato, Takuya; Asai, Masato; Enomoto, Atsushi; Ushida, Kaori; Sobue, Sayaka; Ichihara, Masatoshi; Takahashi, Masahide

    2012-10-01

    CD109, a glycosylphosphatidylinositol-anchored glycoprotein, is highly expressed in several types of human cancer tissues, in particular, squamous cell carcinomas. In normal human tissues, human CD109 expression is limited to certain cell types including myoepithelial cells of the mammary, lacrimal, salivary, and bronchial glands and basal cells of the prostate and bronchial epithelium. Although CD109 has been reported to negatively regulate transforming growth factor-β signaling in keratinocytes in vitro, its physiologic role in vivo remains largely unknown. To investigate the function of CD109 in vivo, we generated CD109-deficient (CD109(-/-)) mice. Although CD109(-/-) mice were born normally, transient impairment of hair growth was observed. At histologic analysis, kinked hair shafts, ectatic hair follicles with an accumulation of sebum, and persistent hyperplasia of the epidermis and sebaceous glands were observed in CD109(-/-) mice. Immunohistochemical analysis revealed thickening of the basal and suprabasal layers in the epidermis of CD109(-/-) mice, which is where endogenous CD109 is expressed in wild-type mice. Although CD109 was reported to negatively regulate transforming growth factor-β signaling, no significant difference in levels of Smad2 phosphorylation was observed in the epidermis between wild-type and CD109(-/-) mice. Instead, Stat3 phosphorylation levels were significantly elevated in the epidermis of CD109(-/-) mice compared with wild-type mice. These results suggest that CD109 regulates differentiation of keratinocytes via a signaling pathway involving Stat3.

  5. Atrial septal stenting - How I do it?

    Directory of Open Access Journals (Sweden)

    Kothandam Sivakumar

    2015-01-01

    Full Text Available A wide atrial communication is important to maintain hemodynamics in certain forms of congenital and acquired heart defects. In comparison to balloon septostomy or blade septostomy, atrial septal stenting provides a controlled, predictable, and long-lasting atrial communication. It often needs a prior Brockenbrough needle septal puncture to obtain a stable stent position. A stent deployed across a previously dilated and stretched oval foramen or tunnel form of oval foramen carries higher risk of embolization. This review provides technical tips to achieve a safe atrial septal stenting. Even though this is a "How to do it article," an initial discussion about the indications for atrial septal stenting is vital as the resultant size of the atrial septal communication should be tailored for each indication.

  6. Risk of atrial fibrillation in diabetes mellitus

    DEFF Research Database (Denmark)

    Pallisgaard, Jannik L.; Schjerning, Anne-Marie; Lindhardt, Tommi B.

    2016-01-01

    AIM: Diabetes has been associated with atrial fibrillation but the current evidence is conflicting. In particular knowledge regarding young diabetes patients and the risk of developing atrial fibrillation is sparse. The aim of our study was to investigate the risk of atrial fibrillation in patients...... with diabetes compared to the background population in Denmark. METHODS AND RESULTS: Through Danish nationwide registries we included persons above 18 years of age and without prior atrial fibrillation and/or diabetes from 1996 to 2012. The study cohort was divided into a background population without diabetes...... and a diabetes group. The absolute risk of developing atrial fibrillation was calculated and Poisson regression models adjusted for sex, age and comorbidities were used to calculate incidence rate ratios of atrial fibrillation. The total study cohort included 5,081,087 persons, 4,827,713 (95%) in the background...

  7. Atrial – Ventricular Septal Defect

    Directory of Open Access Journals (Sweden)

    T Panagiotopoulos

    2009-05-01

    Full Text Available Atrial and ventricular septal defect constitute the most common congenital heart disease.Aim: Τhe aim of the present retrospective study was to record data and factors that affect atrial and ventricular septal defect.Method and material: The sample study included patients of both sexes who were hospitalized with diagnosis atrial and ventricular septal defect in a Cardiac Surgery hospital of Athens. A specially constructed printed form was used for data collection, where were recorded the demographic and personal variables, the pathological, surgical, cardiology and obstetric history, the habits of adults, as well as the personal characteristics of mothers. Analysis of data was performed by descriptive statistical analysis.Results: The sample study consisted of 101 individuals with diagnosis atrial or ventricular Septal Defect, of which 40% were boys and 60% girls. The 70% of the sample study suffered from atrial Septal Defect and the 30% suffered from ventricular Septal Defect. Regarding age, 12% of the sample study was 0-1 years old, 35% was >1 years old, 8% was >12-18 years old and 45% over than 18 years old. Regarding educational status of the adult participants, 9% was of 0-6 years education, 22%>6 -12 years, 13%>12 years. 14% of the adult paticipants smoked, 4% consumed alcohol and 5% smoked in conjunction with alcohol. In terms of the obstetric history of the sample studied, 32% of the cases had normal birth, 4% had a twin birth and 1% had a triplet one. According to the variables related to mothers, the mean age of the mother was 30 years and 3 months, 10% were smokers at pregnancy and 3% used chemical substance and mainly hair color. Also, the results of the present study showed that individuals of 12-18 and >18 years old did not suffer from ventricular Septal Defect, whereas the infants 0-1 years old did not suffer from Atrial Septal Defect. The mean value of age at the admission in intensive care unit was 7 months (12% for the infants

  8. Impact of stepwise ablation on the biatrial substrate in patients with persistent atrial fibrillation and heart failure.

    Science.gov (United States)

    Jones, David G; Haldar, Shouvik K; Jarman, Julian W E; Johar, Sofian; Hussain, Wajid; Markides, Vias; Wong, Tom

    2013-08-01

    Ablation of persistent atrial fibrillation can be challenging, often involving not only pulmonary vein isolation (PVI) but also additional linear lesions and ablation of complex fractionated electrograms (CFE). We examined the impact of stepwise ablation on a human model of advanced atrial substrate of persistent atrial fibrillation in heart failure. In 30 patients with persistent atrial fibrillation and left ventricular ejection fraction ≤35%, high-density CFE maps were recorded biatrially at baseline, in the left atrium (LA) after PVI and linear lesions (roof and mitral isthmus), and biatrially after LA CFE ablation. Surface area of CFE (mean cycle length ≤120 ms) remote to PVI and linear lesions, defined as CFE area, was reduced after PVI (18.3±12.03 to 10.2±7.1 cm(2); PCFE reduction (P=0.02). Right atrial CFE area was reduced by LA ablation, from 25.9±14.1 to 12.9±11.8 cm(2) (PCFE area was progressively reduced following PVI and linear lesions, and LA ablation reduced right atrial CFE area. Reduction of CFE area at sites remote from ablation would suggest either regression of the advanced atrial substrate or that these CFE were functional phenomena. Nevertheless, in an advanced atrial fibrillation substrate, linear lesions after PVI diminished the target area for CFE ablation, and complete lesions resulted in a favorable clinical outcome.

  9. Changes of IK,ATP current density and allosteric modulation during chronic atrial fibrillation

    Institute of Scientific and Technical Information of China (English)

    WU Gang; HUANG Cong-xin; TANG Yan-hong; JIANG Hong; WAN Jun; CHEN Hui; XIE Qiang; HUANG Zheng-rong

    2005-01-01

    Background Atrial fibrillation (AF) is the most common supraventricular arrhythmia in clinical practice. Chronic atrial fibrillation (CAF) is associated with ionic remodeling. However, little is known about the activity of ATP-sensitive potassium current (IK,ATP) during CAF. So we studied the changes of IK,ATP density and allosteric modulation of ATP-sensitivity by intracellular pH during CAF.Methods Myocardium samples were obtained from the right auricular appendage of patients with rheumatic heart disease complicated with valvular disease in sinus rhythm (SR) or CAF. There were 14 patients in SR group and 9 patients in CAF group. Single atrial cells were isolated using an enzyme dispersion technique. IK,ATP was recorded using the whole-cell and inside-out configuration of voltage-clamp techniques. In whole-cell model, myocytes of SR and CAF groups were perfused with simulated ischemic solution to elicit IK,ATP. In inside-out configuration, the internal patch membranes were exposed to different ATP concentrations in pH 7.4 and 6.8.Results Under simulated ischemia, IK,ATP current density of CAF group was significantly higher than in SR group [(83.5±10.8) vs. (58.7±8.4) pA/pF, P<0.01]. IK,ATP of the two groups showed ATP concentration-dependent inhibition. The ATP concentration for 50% current inhibition (IC50) for the SR group was significantly different in pH 7.4 and pH 6.8 (24 vs. 74 μmol/L, P<0.01). The IC50 did not change significantly in CAF group when the pH decreased from 7.4 to 6.8.Conclusions During CAF, IK,ATP current density was increased and its allosteric modulation of ATP-sensitivity by intracellular pH was diminished.

  10. ANALYSIS OF RANDOMNESS OF ATRIAL AND VENTRICULAR RHYTHM IN ATRIAL-FIBRILLATION

    NARCIS (Netherlands)

    VANDENBERG, MP; DELANGEN, CDJ; HAAKSMA, J; BEL, KJ; CRIJNS, HJGM; DIJK, WA; LIE, KI

    1995-01-01

    The aim of the present study was top examine the relationship between randomness of atrial and ventricular rhythm during atrial fibrillation. Atrial fibrillation was induced in 10 open-chest pigs by application of metacholine on the surface of the right atrium followed by incremental pacing. Local a

  11. Correlation of Left Atrial Diameter by Echocardiography and Left Atrial Volume by Computed Tomography

    NARCIS (Netherlands)

    Hof, Irene; Arbab-Zadeh, Armin; Scherr, Daniel; Chilukuri, Karuna; Dalal, Darshan; Abraham, Theodore; Lima, Joao; Calkins, Hugh

    2009-01-01

    Computed Tomography. Introduction: For patients undergoing catheter ablation of atrial fibrillation (AF), left atrial size is a predictor of recurrence of AF during follow-up. For this reason, major clinical trials have used a left atrial diameter (LAD) of more than 5.0 or 5.5 cm, assessed by echoca

  12. The effects of rhythm control strategies versus rate control strategies for atrial fibrillation and atrial flutter

    DEFF Research Database (Denmark)

    Sethi, Naqash; Safi, Sanam; Nielsen, Emil E

    2017-01-01

    BACKGROUND: Atrial fibrillation is the most common arrhythmia of the heart with a prevalence of approximately 2% in the western world. Atrial flutter, another arrhythmia, occurs less often with an incidence of approximately 200,000 new patients per year in the USA. Patients with atrial fibrillation...... as healthcare systems and healthcare economy. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42016051433....

  13. Atrial fibrillation in the elderly

    Institute of Scientific and Technical Information of China (English)

    Roger Kerzner; Michael W. Rich

    2005-01-01

    Atrial fibrillation (AF) is an extremely common condition in the elderly, with increasing prevalence around the world as the population ages. AF may be associated with serious health consequences, including stroke, heart failure, and decreased quality of life, so that careful management of AF by geriatric health care providers is required. With careful attention to anticoagulation therapy, and prudent use of medications and invasive procedures to minimize symptoms, many of the adverse health consequences of AF can be prevented.

  14. CORRELATION OF LEFT ATRIAL SIZE AND ATRIAL FIBRILLATION IN RHD WITH MITRAL VALVE DISEASE

    Directory of Open Access Journals (Sweden)

    Raghavendra

    2016-03-01

    Full Text Available BACKGROUND Atrial fibrillation (AF, the most common sustained cardiac rhythm disturbance, commonly occurs with rheumatic heart disease, particularly mitral stenosis. Hemodynamic impairment and thromboembolic events result in significant morbidity& mortality. Left atrial (LA enlargement is one of the elements that evolve in the natural history of mitral stenosis. The objective of this study is to study the relation between echo cardio graphically determined left atrial size and atrial fibrillation in mitral valve disease (MVD. METHODOLOGY 50 Patients with rheumatic heart disease with mitral valve disease were studied using ECG and ECHO, excluding patients with congenital heart diseases, non-rheumatic mitral valve disease, essential hypertension, patients undergone PTMC or valvuloplasty or valve replacement, coronary artery diseases, patients on antiarrhythmic drugs, pregnant women. Left atrial dimensions measured by ECHO in patients of MVD and AF on ECG were compared with the left atrial dimension of patients in sinus rhythm. RESULTS In this study 42 patients had left atrial size >40 mm, 29(93.55% of them were in atrial fibrillation and only 13(68.42% were in sinus rhythm. Among 8 patients with left atrial size <40 mm, 2(6.45% were in atrial fibrillation and 06(31.58% were in sinus rhythm with p<0.02 which is significant. CONCLUSION Atrial fibrillation incidence was common when left atrial dimension was above 40 mm. There is a quantitative relation between left atrial size measured echocardiographically and the presence or absence of atrial fibrillation. These results may have therapeutic implication in that it may be possible with echocardiography, to identify patients in sinus rhythm, who are at high risk of developing atrial fibrillation. Prophylactic anticoagulation, antiarrhythmic therapy or both might be considered in management to prevent embolism.

  15. Awkward Appendages: Comic Umbrellas in Nineteenth-Century Print Culture

    DEFF Research Database (Denmark)

    Damkjær, Maria

    2017-01-01

    In nineteenth-century comic writing, the umbrella represents a troublesome material world: umbrellas were always threatening to break, flip inside out or to disappear and reappear in the most mysterious fashion. The umbrella was a trope for oddness, resistance and perversity of intent. With the h......In nineteenth-century comic writing, the umbrella represents a troublesome material world: umbrellas were always threatening to break, flip inside out or to disappear and reappear in the most mysterious fashion. The umbrella was a trope for oddness, resistance and perversity of intent....... With the help of Alenka Zupančič’s theory of comedy, this article argues that the umbrella in the cultural imagination marks an unreliable world of signs. Umbrellas, with their troublesome peripatetic nature, become arbiters of human destiny. Comic writers, including Robert Louis Stevenson in ‘The Philosophy...

  16. Bacterial surface appendages strongly impact nanomechanical and electrokinetic properties of Escherichia coli cells subjected to osmotic stress.

    Directory of Open Access Journals (Sweden)

    Grégory Francius

    Full Text Available The physicochemical properties and dynamics of bacterial envelope, play a major role in bacterial activity. In this study, the morphological, nanomechanical and electrohydrodynamic properties of Escherichia coli K-12 mutant cells were thoroughly investigated as a function of bulk medium ionic strength using atomic force microscopy (AFM and electrokinetics (electrophoresis. Bacteria were differing according to genetic alterations controlling the production of different surface appendages (short and rigid Ag43 adhesins, longer and more flexible type 1 fimbriae and F pilus. From the analysis of the spatially resolved force curves, it is shown that cells elasticity and turgor pressure are not only depending on bulk salt concentration but also on the presence/absence and nature of surface appendage. In 1 mM KNO(3, cells without appendages or cells surrounded by Ag43 exhibit large Young moduli and turgor pressures (∼700-900 kPa and ∼100-300 kPa respectively. Under similar ionic strength condition, a dramatic ∼50% to ∼70% decrease of these nanomechanical parameters was evidenced for cells with appendages. Qualitatively, such dependence of nanomechanical behavior on surface organization remains when increasing medium salt content to 100 mM, even though, quantitatively, differences are marked to a much smaller extent. Additionally, for a given surface appendage, the magnitude of the nanomechanical parameters decreases significantly when increasing bulk salt concentration. This effect is ascribed to a bacterial exoosmotic water loss resulting in a combined contraction of bacterial cytoplasm together with an electrostatically-driven shrinkage of the surface appendages. The former process is demonstrated upon AFM analysis, while the latter, inaccessible upon AFM imaging, is inferred from electrophoretic data interpreted according to advanced soft particle electrokinetic theory. Altogether, AFM and electrokinetic results clearly demonstrate the

  17. Optimisation of Ionic Models to Fit Tissue Action Potentials: Application to 3D Atrial Modelling

    Directory of Open Access Journals (Sweden)

    Amr Al Abed

    2013-01-01

    Full Text Available A 3D model of atrial electrical activity has been developed with spatially heterogeneous electrophysiological properties. The atrial geometry, reconstructed from the male Visible Human dataset, included gross anatomical features such as the central and peripheral sinoatrial node (SAN, intra-atrial connections, pulmonary veins, inferior and superior vena cava, and the coronary sinus. Membrane potentials of myocytes from spontaneously active or electrically paced in vitro rabbit cardiac tissue preparations were recorded using intracellular glass microelectrodes. Action potentials of central and peripheral SAN, right and left atrial, and pulmonary vein myocytes were each fitted using a generic ionic model having three phenomenological ionic current components: one time-dependent inward, one time-dependent outward, and one leakage current. To bridge the gap between the single-cell ionic models and the gross electrical behaviour of the 3D whole-atrial model, a simplified 2D tissue disc with heterogeneous regions was optimised to arrive at parameters for each cell type under electrotonic load. Parameters were then incorporated into the 3D atrial model, which as a result exhibited a spontaneously active SAN able to rhythmically excite the atria. The tissue-based optimisation of ionic models and the modelling process outlined are generic and applicable to image-based computer reconstruction and simulation of excitable tissue.

  18. PAROXYSMAL ATRIAL FIBRILLATION: CHOICE OF CARDIOVERSION THERAPY

    Directory of Open Access Journals (Sweden)

    B. A. Tatarskii

    2007-01-01

    Full Text Available Characteristics and classification of different patterns of paroxysmal atrial fibrillation are presented. Main indications to restoration of sinus rhythm are discussed. The features of main medications used to terminate of atrial fibrillation are given. The choice of antiarrhythmic drug is considerate. Necessity of individual approach to therapy tactics is proved.

  19. A novel and simple atrial retractor.

    Science.gov (United States)

    Kofidis, Theo; Lee, Chuen Neng

    2011-05-01

    Minimally invasive cardiac operations require specialized equipment. Atrial retractors are a frequently used tool to expose heart valves for minimally invasive and open procedures. The models currently available in the market are efficient; however, they may be complex, bulky, or expensive. We introduce a novel, very simple atrial retractor we designed using ubiquitously available materials.

  20. Atrial Arrhythmia Summit: Post Summit Report

    Science.gov (United States)

    Barr, Yael

    2010-01-01

    The Atrial Arrhythmia Summit brought together nationally and internationally recognized experts in cardiology, electrophysiology, exercise physiology, and space medicine in an effort to elucidate the mechanisms, risk factors, and management of atrial arrhythmias in the unique occupational cohort of the U.S. astronaut corps.

  1. Corticosteroids and the risk of atrial fibrillation

    NARCIS (Netherlands)

    van der Hooft, CS; Heeringa, J; Brusselle, GG; Hofman, A; Witteman, JCM; Kingma, JH; Sturkenboom, MCJM; Stricker, BHC

    2006-01-01

    Background: High-dose ( pulse) corticosteroid therapy has been associated with the development of atrial fibrillation. This association, however, is mainly based on case reports. Methods: To test the hypothesis that high-dose corticosteroid exposure increases the risk of new-onset atrial fibrillatio

  2. Atrial fibrillation in rats induced by rapid transesophageal atrial pacing during brief episodes of asphyxia: A new in vivo model

    DEFF Research Database (Denmark)

    Haugan, K.; Lam, Henrik Rye; Knudsen, C. B.;

    2004-01-01

    Non-pharmacological in vivo models of atrial fibrillation (AF) have been developed in large animals only. We aimed to develop and characterize a new small animal non-pharmacological in vivo model of AF. AF was induced by transesophageal atrial burst pacing during 35 seconds periods of asphyxia...... was associated with a marked profibrillatory effect. Increasing gap junction intracellular communication using the antiarrhythmic peptide analogue AAP 10 did not affect AF duration. Basal plasma level of epinephrine and norepinephrine were increased 5- to 20-fold relative to values reported by others......, but unchanged following 35 seconds of asphyxia. The results from our study demonstrate that the rat model shares several clinical key characteristics with human AF: (1) hemodynamic response to AF; (2) increased autonomic tone; (3) antiarrhythmic effects of clinically used drugs; (4) profibrillatory effect...

  3. Atrial Remodeling And Atrial Fibrillation: Mechanistic Interactions And Clinical Implications

    OpenAIRE

    2009-01-01

    Atrial fibrillation (AF) is the most common arrhythmia in clinical practice. The prevalence of AF increases dramatically with age and is seen in as high as 9% of individuals by the age of 80 years. In high-risk patients, the thromboembolic stroke risk can be as high as 9% per year and is associated with a 2-fold increase in mortality. Although the pathophysiological mechanism underlying the genesis of AF has been the focus of many studies, it remains only partially understood. Conventional th...

  4. The cephalopod arm crown: appendage formation and differentiation in the Hawaiian bobtail squid Euprymna scolopes.

    Science.gov (United States)

    Nödl, Marie-Therese; Kerbl, Alexandra; Walzl, Manfred G; Müller, Gerd B; de Couet, Heinz Gert

    2016-01-01

    Cephalopods are a highly derived class of molluscs that adapted their body plan to a more active and predatory lifestyle. One intriguing adaptation is the modification of the ventral foot to form a bilaterally symmetric arm crown, which constitutes a true morphological novelty in evolution. In addition, this structure shows many diversifications within the class of cephalopods and therefore offers an interesting opportunity to study the molecular underpinnings of the emergence of phenotypic novelties and their diversification. Here we use the sepiolid Euprymna scolopes as a model to study the formation and differentiation of the decabrachian arm crown, which consists of four pairs of sessile arms and one pair of retractile tentacles. We provide a detailed description of arm crown formation in order to understand the basic morphology and the developmental dynamics of this structure. We show that the morphological formation of the cephalopod appendages occurs during distinct phases, including outgrowth, elongation, and tissue differentiation. Early outgrowth is characterized by uniform cell proliferation, while the elongation of the appendages initiates tissue differentiation. The latter progresses in a gradient from proximal to distal, whereas cell proliferation becomes restricted to the distal-most end of the arm. Differences in the formation of arms and tentacles exist, with the tentacles showing an expedite growth rate and higher complexity at younger stages. The early outgrowth and differentiation of the E. scolopes arm crown shows similarities to the related, yet derived cephalopod Octopus vulgaris. Parallels in the growth and differentiation of appendages seem to exist throughout the animal kingdom, raising the question of whether these similarities reflect a recruitment of similar molecular patterning pathways.

  5. Atrial fibrillation in patients with ischemic stroke

    DEFF Research Database (Denmark)

    Thygesen, Sandra Kruchov; Frost, Lars; Eagle, Kim A;

    2009-01-01

    BACKGROUND: Atrial fibrillation is a major risk factor for ischemic stroke. However, the prognostic impact of atrial fibrillation among patients with stroke is not fully clarified. We compared patient characteristics, including severity of stroke and comorbidity, quality of in-hospital care...... and outcomes in a cohort of first-time ischemic stroke patients with and without atrial fibrillation. METHODS: Based on linkage of public medical databases, we did a population-based follow-up study among 3,849 stroke patients from the County of Aarhus, Denmark admitted in the period of 2003......-2007 and prospectively registered in the Danish National Indicator Project. RESULTS: Atrial fibrillation was associated with an adverse prognostic profile but not with an overall poorer quality of in-hospital care. Patients with atrial fibrillation had a longer total length of stay (median: 15 vs 9 days), and were...

  6. 风湿性心房颤动患者左心房组织中钙蛋白酶-2的表达%Expression of calpain-2 in human left atrium in rheumatic atrial fibrillation

    Institute of Scientific and Technical Information of China (English)

    韩波; 王建春; 张涛; 朱小龙; 李丛; 王正军; 赵勇; 邹承伟

    2014-01-01

    目的:观察风湿性心房颤动(AF)患者左心房中钙蛋白酶-2(calpain-2)的表达,探讨其在AF发病机制中的作用。方法选取外科换瓣手术的风湿性心脏病患者39例,分为窦性心律组( n=16例)和心房颤动组( n=23例)。应用RT-PCR技术和免疫组化LSAB法半定量检测calpain-2的表达。结果心房颤动组calpain-2 mRNA的deltaCt值高于窦性心律组[(0.091±0.035) vs (0.066±0.022),P=0.017];两组左心房心肌细胞中均有棕黄色颗粒沉着,心外膜和心内膜细胞均未见棕黄色颗粒;心房颤动组中calpain-2表达含量明显高于窦性心律组( P<0.001),两者平均光密度值分别为0.92±0.17和0.65±0.01;calpain-2的含量与左心房收缩末期直径呈正相关(r=0.929, P<0.001)。结论 calpain-2在人类左心房心肌细胞中表达;AF时calpain-2的表达明显增加。%Objective To observe the expression of calpain-2 in the left atrum of patients with rheumatic atrial fibrilla-tion, and to explore its roles in the pathogenesis of atrial fibrillation.Methods A total of 39 patients with rheumatic heart disease who received surgical valve replacement were divided into two groups: the atrial fibrillation group ( n=23) and sinus rhythm group (n=16).The expression of calpain-2 was detected with LSAB immunohistochemical and the Real-time PCR technology.Results The deltaCt of calpain-2 mRNA of the atrial fibrillation group ( 0.091 ± 0.035) was higher than that of the sinus rhythm group (0.066 ±0.022, P=0.017).Brown particle deposits were ob-served in the left atrial myocytes in both groups, but the epicardial and endocardial cells showed no brown particles.The average optical density values of calpain-2 of the atrial fibrillation group and sinus rhythm group were (0.92 ±0.17) and (0.65 ±0.01)(P<0.001).Calpain-2 levels and left atrial systolic diameter were correlated (r=0.929, P<0.01).Conclusion

  7. Artificial atrial fibrillation in the dog. An artifact?

    NARCIS (Netherlands)

    Strackee, J.; Hoelen, A.J.; Zimmerman, A.N.E.; Meijler, F.L.

    1971-01-01

    R-R interval sequences during artificial atrial fibrillation in dogs were studied in the same way as in patients in a previous study and compared with results obtained in dogs with spontaneous atrial fibrillation. Artificial atrial fibrillation was effected by right atrial stimulation in three close

  8. Galectin-3 in patients undergoing ablation of atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Nicolas Clementy

    2014-11-01

    Conclusions: Persistent type of atrial fibrillation is an independent predictor of higher Galectin-3 concentration. This biomarker of fibrosis may be implied in the mechanisms of atrial remodeling and maintenance of atrial fibrillation, and thus be helpful for the design of therapeutic strategy in patients with atrial fibrillation.

  9. Left atrial thrombus resolution in atrial fibrillation or flutter: Results of a prospective study with rivaroxaban (X-TRA) and a retrospective observational registry providing baseline data (CLOT-AF).

    Science.gov (United States)

    Lip, Gregory Y H; Hammerstingl, Christoph; Marin, Francisco; Cappato, Riccardo; Meng, Isabelle Ling; Kirsch, Bodo; van Eickels, Martin; Cohen, Ariel

    2016-08-01

    Data on left atrial/left atrial appendage (LA/LAA) thrombus resolution after non-vitamin K antagonist (VKA) oral anticoagulant treatment are scarce. The primary objective of X-TRA was to explore the use of rivaroxaban for the resolution of LA/LAA thrombi in patients with nonvalvular atrial fibrillation (AF) or atrial flutter, with the CLOT-AF registry providing retrospective data after standard-of-care therapy in this setting. X-TRA was a prospective, single-arm, open-label, multicenter study that investigated rivaroxaban treatment for 6 weeks for LA/LAA thrombus resolution in patients with nonvalvular AF or atrial flutter and LA/LAA thrombus confirmed at baseline on a transesophageal echocardiogram (TEE). CLOT-AF retrospectively collected thrombus-related patient outcome data after standard-of-care anticoagulant treatment for 3 to 12 weeks in patients with nonvalvular AF or atrial flutter who had LA/LAA thrombi on TEE recorded in their medical file. In X-TRA, patients were predominantly (95.0%) from Eastern European countries. The adjudicated thrombus resolution rate was 41.5% (22/53 modified intention-to-treat [mITT] patients, 95% CI 28.1%-55.9%) based on central TEE assessments. Resolved or reduced thrombus was evident in 60.4% (32/53 mITT patients, 95% CI 46.0%-73.6%) of patients. In CLOT-AF, the reported thrombus resolution rate was 62.5% (60/96 mITT patients, 95% CI 52.0%-72.2%) and appeared better in Western European countries (34/50; 68.0%) than in Eastern European countries (26/46; 56.5%). X-TRA is the first prospective, multicenter study examining LA/LAA thrombus resolution with a non-VKA oral anticoagulant in VKA-naïve patients or in patients with suboptimal VKA therapy. Rivaroxaban could be a potential option for the treatment of LA/LAA thrombi. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  10. Surgical Treatment of Concomitant Atrial Fibrillation: Focus onto Atrial Contractility

    Directory of Open Access Journals (Sweden)

    Claudia Loardi

    2015-01-01

    Full Text Available Background. Maze procedure aims at restoring sinus rhythm (SR and atrial contractility (AC. This study evaluated multiple aspects of AC recovery and their relationship with SR regain after ablation. Methods. 122 mitral and fibrillating patients underwent radiofrequency Maze. Rhythm check and echocardiographic control of biatrial contractility were performed at 3, 6, 12, and 24 months postoperatively. A multivariate Cox analysis of risk factors for absence of AC recuperation was applied. Results. At 2-years follow-up, SR was achieved in 79% of patients. SR-AC coexistence increased from 76% until 98%, while biatrial contraction detection augmented from 84 to 98% at late stage. Shorter preoperative arrhythmia duration was the only common predictor of SR-AC restoring, while pulmonary artery pressure (PAP negatively influenced AC recuperation. Early AC restoration favored future freedom from arrhythmia recurrence. Minor LA dimensions correlated with improved future A/E value and vice versa. Right atrial (RA contractility restoring favored better left ventricular (LV performance and volumes. Conclusions. SR and left AC are two interrelated Maze objectives. Factors associated with arrhythmia “chronic state” (PAP and arrhythmia duration are negative predictors of procedural success. Our results suggest an association between postoperative LA dimensions and “kick” restoring and an influence of RA contraction onto LV function.

  11. Left atrial ball valve thrombus

    Directory of Open Access Journals (Sweden)

    R. Balaji

    2013-10-01

    Full Text Available "Ball valve thrombus" which is a spherical free floating clot in left atrium is an often quoted, but uncommonly encountered complication in patients with severe mitral stenosis of rheumatic origin, who are in atrial fibrillation. We describe the case of a 31-year-old lady with rheumatic heart disease, severe mitral stenosis and moderately severe aortic stenosis who had undergone closed mitral valvotomy 13 years ago. The patient presented with an episode of non-exertional syncope and breathlessness on exertion of 6 months duration and was in normal sinus rhythm. Echocardiography facilitated ante-mortem diagnosis and prompt institution of surgery was life saving.

  12. Atrial and ventricular volume and function in persistent and permanent atrial fibrillation, a magnetic resonance imaging study

    DEFF Research Database (Denmark)

    Therkelsen, Susette Krohn; Groenning, Bjoern Aaris; Svendsen, Jesper Hastrup

    2005-01-01

    Left atrial size is independently related to cardiovascular morbidity and mortality, and atrial fibrillation (AF) is strongly associated with atrial size. Our aims were to report atrial and ventricular dimensions in patients with AF evaluated with magnetic resonance imaging (MRI), and to assess t...

  13. A functional polymorphism C-509T in TGFβ-1 promoter contributes to susceptibility and prognosis of lone atrial fibrillation in Chinese population.

    Directory of Open Access Journals (Sweden)

    Hailong Cao

    Full Text Available Transforming growth factor-β1 (TGF-β1 is an important mediator of atrial fibrosis and atrial fibrillation (AF. But the involved genetic mechanism is unknown. Herein, the TGF-β1 C-509 T polymorphism (rs1800469 was genotyped in a case-control study of 840 patients and 845 controls in Chinese population to explore the association between the polymorphism and susceptibility and prognosis of lone AF. As a result, the CT and/or TT genotypes had an increased lone AF risk [adjusted odds ratio (OR = 1.50 for CT, OR = 3.72 for TT, and OR = 2.15 for CT/TT], compared with the TGF-β1CC genotype. Moreover, patients carrying CT/TT genotypes showed a higher possibility of AF recurrence after catheter ablation, compared with patients carrying CC genotype. In a genotype-phenotype correlation analysis using 24 normal left atrial appendage samples, increasing gradients of atrial TGF-β1 expression levels positively correlated with atrial collagen volume fraction were identified in samples with CC, CT and TT genotypes. The in vitro luciferase assays also showed a higher luciferase activity of the -509 T allele than that of the -509 C allele. In conclusion, the TGF-β1 C-509 T polymorphism is involved in the etiology of lone AF and thus may be a marker for genetic susceptibility to lone AF and predicting prognosis after catheter ablation in Chinese populations. Therefore, we provide new information about treatment strategies and our understanding of TGF-β1 in AF.

  14. Mapping strategy for multiple atrial tachyarrhythmias in a transplant heart

    DEFF Research Database (Denmark)

    Jin, Qi; Pehrson, Steen; Jacobsen, Peter Karl;

    2015-01-01

    BACKGROUND: Different atrial arrhythmias can coexist in the recipient and donor atria after heart transplantation. CASE PRESENTATION: We report an unusual case of a patient with three different types of atrial arrhythmia after heart transplantation: an atrial fibrillation in the recipient atria....... CONCLUSIONS: It is critical to understand the surgical anatomy of a bi-atrial anastomosis and its relevant electrical activation pattern before ablation. Appropriate electroanatomical mapping strategy with RMN can facilitate the successful ablation of post-transplant atrial arrhythmias....

  15. Age-related changes in dispersion of atrial effective refractory period and its ionic mechanism in canines

    Institute of Scientific and Technical Information of China (English)

    SUN Qi; TANG Min; LI Ning; PU Jie-lin; ZHANG Shu

    2007-01-01

    @@ Atrial fibrillation (AF) is the most common cardiac arrhythmia in man, and epidemiological study has shown the close relationship between the incidence of AF and aging.1 Although the effects of aging on atrial electrophysiology have been investigated in humans and animal models,2-9 the electrophysiological changes that make the atria of aged individuals more susceptible to AF than those of adults remain poorly understood.

  16. Analytical method for the attitude stability of partially liquid filled spacecraft with flexible appendage

    Science.gov (United States)

    Yan, Yulong; Yue, Baozeng

    2017-02-01

    In this paper, the attitude stability of liquid-filled spacecraft with flexible appendage is investigated. The motion of liquid sloshing is modeled as the spherical pendulum, and the flexible appendage is approached by a linear shearing beam. Nonlinear dynamic equations of the coupled system are derived from the Hamiltonian. The stability of the coupled system was analyzed by using the energy-Casimir method, and the nonlinear stability theorem of the coupled spacecraft system was also obtained. Through numerical computation, the correctness of the proposed theorem is verified and the boundary curves of the stable region are presented. The increase of the angular velocity and flexible attachment length will weaken the attitude stability, and the change of the filled ratio of liquid fuel tank has a different influence on the stability of the coupled spacecraft, depending on the different conditions. The attitude stability analysis of the coupled spacecraft system in this context is useful for selecting appropriate parameters in the complex spacecraft design.

  17. Evaluation of body appendage injuries to juvenile signal crayfish (Pacifastacus leniusculus: relationships and consequences

    Directory of Open Access Journals (Sweden)

    Kouba A.

    2011-05-01

    Full Text Available Aggressive behaviour occurs frequently in crayfish and commonly results in injuries to body appendages. This study aimed to evaluate injuries to antennae, chelae, and walking legs of juvenile signal crayfish after seven months of rearing at high stocking density. We suggest that the high incidence of antennae injuries (66.8% is related to their delicate structure and exposed position, which makes them vulnerable to damage. Chelae were more frequently injured (45.5% than walking legs (7.8–23.6%. Considering the robustness of these structures and the scarcity of animals with both chelae missing and/or regenerating (4.9%, it seemed that injured animals were often killed by less injured ones. Antennae of crayfish with a single injured chela were more frequently injured on the side of the body with the damaged chela, and a similar pattern was observed for walking legs. Expanding on previous research reporting a negative relationship only between incidence of chela injury and crayfish size, we found this relationship to be significant for all evaluated appendages. We hypothesize that any injury and accompanying regeneration may have significant impact on subsequent injuries, overall growth, and reproductive success, and may result in death through cannibalism.

  18. Effect of Red Clover Isoflavones over Skin, Appendages, and Mucosal Status in Postmenopausal Women

    Directory of Open Access Journals (Sweden)

    Markus Lipovac

    2011-01-01

    Full Text Available Objective. Evaluate in postmenopausal women the effect of red clover extract (RCE isoflavones over subjective status of skin, appendages, and several mucosal sites. Method. Postmenopausal women (n=109 were randomly assigned to receive either two daily capsules of the active compound (80 mg RCE, Group A or placebo of equal appearance (Group B for a 90-day period. After a washout period of 7 days, medication was crossed over and taken for 90 days more. Subjective improvement of skin, appendages, and several mucosal site status was assessed for each studied group at 90 and 187 days using a visual analogue scale (VAS. In addition, libido, tiredness, and urinary, sleep, and mood complaints were also evaluated. Results. Women after RCE intervention (both groups reported better subjective improvement of scalp hair and skin status, libido, mood, sleep, and tiredness. Improvement of urinary complaints, nail, body hair, and mucosa (oral, nasal, and ocular status did not differ between treatment phases (intra- and intergroup. Overall satisfaction with treatment was reported higher after RCE intervention (both groups as compared to placebo. Conclusion. RCE supplementation exerted a subject improvement of scalp hair and skin status as well as libido, mood, sleep, and tiredness in postmenopausal women.

  19. Analytical method for the attitude stability of partially liquid filled spacecraft with flexible appendage

    Science.gov (United States)

    Yan, Yulong; Yue, Baozeng

    2016-11-01

    In this paper, the attitude stability of liquid-filled spacecraft with flexible appendage is investigated. The motion of liquid sloshing is modeled as the spherical pendulum, and the flexible appendage is approached by a linear shearing beam. Nonlinear dynamic equations of the coupled system are derived from the Hamiltonian. The stability of the coupled system was analyzed by using the energy-Casimir method, and the nonlinear stability theorem of the coupled spacecraft system was also obtained. Through numerical computation, the correctness of the proposed theorem is verified and the boundary curves of the stable region are presented. The increase of the angular velocity and flexible attachment length will weaken the attitude stability, and the change of the filled ratio of liquid fuel tank has a different influence on the stability of the coupled spacecraft, depending on the different conditions. The attitude stability analysis of the coupled spacecraft system in this context is useful for selecting appropriate parameters in the complex spacecraft design.

  20. Trichohyalin-like proteins have evolutionarily conserved roles in the morphogenesis of skin appendages.

    Science.gov (United States)

    Mlitz, Veronika; Strasser, Bettina; Jaeger, Karin; Hermann, Marcela; Ghannadan, Minoo; Buchberger, Maria; Alibardi, Lorenzo; Tschachler, Erwin; Eckhart, Leopold

    2014-11-01

    S100 fused-type proteins (SFTPs) such as filaggrin, trichohyalin, and cornulin are differentially expressed in cornifying keratinocytes of the epidermis and various skin appendages. To determine evolutionarily conserved, and thus presumably important, features of SFTPs, we characterized nonmammalian SFTPs and compared their amino acid sequences and expression patterns with those of mammalian SFTPs. We identified an ortholog of cornulin and a previously unknown SFTP, termed scaffoldin, in reptiles and birds, whereas filaggrin was confined to mammals. In contrast to mammalian SFTPs, both cornulin and scaffoldin of the chicken are expressed in the embryonic periderm. However, scaffoldin resembles mammalian trichohyalin with regard to its expression in the filiform papillae of the tongue and in the epithelium underneath the forming tips of the claws. Furthermore, scaffoldin is expressed in the epithelial sheath around growing feathers, reminiscent of trichohyalin expression in the inner root sheath of hair. The results of this study show that SFTP-positive epithelia function as scaffolds for the growth of diverse skin appendages such as claws, nails, hair, and feathers, indicating a common evolutionary origin.

  1. Robotic and mathematical modeling reveal general principles of appendage control and coordination in terrestrial locomotion

    Science.gov (United States)

    McInroe, Benjamin; Astley, Henry; Gong, Chaohui; Kawano, Sandy; Schiebel, Perrin; Choset, Howie; Goldman, Daniel I.

    The transition from aquatic to terrestrial life presented new challenges to early walkers, necessitating robust locomotion on complex, flowable substrates (e.g. sand, mud). Locomotion on such substrates is sensitive to limb morphology and kinematics. Although early walker morphologies are known, principles of appendage control remain elusive. To reveal limb control strategies that facilitated the invasion of land, we study both robotic and mathematical models. Robot experiments show that an active tail is critical for robust locomotion on granular media, enabling locomotion even with poor foot placement and limited ability to lift the body. Using a granular resistive force theory model, we construct connection vector fields that reveal how appendage coordination and terrain inclination impact locomotor performance. This model replicates experimental results, showing that moving limbs/tail in phase is most effective (suggesting a locomotor template). Varying limb trajectories and contacts, we find gaits for which tail use can be neutral or harmful, suggesting limb-tail coordination to be a nontrivial aspect of locomotion. Our findings show that robot experiments coupled with geometric mechanics provide a general framework to reveal principles of robust terrestrial locomotion. This work was supported by NSF PoLS.

  2. Connexins and pannexins in the integumentary system: the skin and appendages.

    Science.gov (United States)

    Faniku, Chrysovalantou; Wright, Catherine S; Martin, Patricia E

    2015-08-01

    The integumentary system comprises the skin and its appendages, which includes hair, nails, feathers, sebaceous and eccrine glands. In this review, we focus on the expression profile of connexins and pannexins throughout the integumentary system in mammals, birds and fish. We provide a picture of the complexity of the connexin/pannexin network illustrating functional importance of these proteins in maintaining the integrity of the epidermal barrier. The differential regulation and expression of connexins and pannexins during skin renewal, together with a number of epidermal, hair and nail abnormalities associated with mutations in connexins, emphasize that the correct balance of connexin and pannexin expression is critical for maintenance of the skin and its appendages with both channel and non-channel functions playing profound roles. Changes in connexin expression during both hair and feather regeneration provide suggestions of specialized communication compartments. Finally, we discuss the potential use of zebrafish as a model for connexin skin biology, where evidence mounts that differential connexin expression is involved in skin patterning and pigmentation.

  3. Atrial fibrillation and survival in colorectal cancer

    Directory of Open Access Journals (Sweden)

    Justin Timothy A

    2004-11-01

    Full Text Available Abstract Background Survival in colorectal cancer may correlate with the degree of systemic inflammatory response to the tumour. Atrial fibrillation may be regarded as an inflammatory complication. We aimed to determine if atrial fibrillation is a prognostic factor in colorectal cancer. Patients and methods A prospective colorectal cancer patient database was cross-referenced with the hospital clinical-coding database to identify patients who had underwent colorectal cancer surgery and were in atrial fibrillation pre- or postoperatively. Results A total of 175 patients underwent surgery for colorectal cancer over a two-year period. Of these, 13 patients had atrial fibrillation pre- or postoperatively. Atrial fibrillation correlated with worse two-year survival (p = 0.04; log-rank test. However, in a Cox regression analysis, atrial fibrillation was not significantly associated with survival. Conclusion The presence or development of atrial fibrillation in patients undergoing surgery for colorectal cancer is associated with worse overall survival, however it was not found to be an independent factor in multivariate analysis.

  4. Anticoagulation therapy for atrial fibrillation.

    Science.gov (United States)

    Hylek, Elaine M

    2013-03-01

    Atrial fibrillation (AF) is the most common significant cardiac rhythm disorder, and its prevalence is increasing worldwide. Atrial fibrillation confers a fivefold increased risk of stroke, and these strokes are associated with significant mortality and disability. The vitamin K antagonist, warfarin, has been the mainstay of anticoagulant therapy for patients with AF, reducing the risk of stroke by 65%. Despite its efficacy, warfarin remains underused in clinical practice because of its variable dose response, diet and medication interactions, and need for frequent monitoring. Stroke prevention in AF has entered an exciting therapeutic era with new classes of targeted anticoagulants that avoid the many pitfalls of the vitamin K antagonists. Dabigatran, an oral thrombin inhibitor, and the factor Xa inhibitors, rivaroxaban and apixaban, have demonstrated efficacy for stroke prevention and a reduced risk of intracranial hemorrhage relative to warfarin. Translating the efficacy of clinical trials into effective use of these novel agents in clinical practice will require an understanding of their pharmacokinetic profiles, dose selection, and management in select clinical situations.

  5. Incidence and clinical predictors of subsequent atrial fibrillation requiring additional ablation after cavotricuspid isthmus ablation for typical atrial flutter.

    Science.gov (United States)

    De Bortoli, Alessandro; Shi, Li-Bin; Ohm, Ole-Jørgen; Hoff, Per Ivar; Schuster, Peter; Solheim, Eivind; Chen, Jian

    2017-06-01

    We sought to investigate the incidence of atrial fibrillation after catheter ablation for typical atrial flutter and to determine the predictors for symptomatic atrial fibrillation that required a further additional dedicated ablation procedure. 127 patients underwent elective cavotricuspid isthmus ablation with the indication of symptomatic, typical atrial flutter. The occurrence of atrial flutter, atrial fibrillation, cerebrovascular events and the need for additional ablation procedures for symptomatic atrial fibrillation was assessed during long-term follow-up. The majority of patients (70%) manifested atrial fibrillation during a follow-up period of 68 ± 24 months, and a significant proportion (42%) underwent one or multiple atrial fibrillation ablation procedures after an average of 26 months from the index procedure. Recurrence of typical atrial flutter was rare. Ten patients (8%) suffered cerebrovascular events. Earlier documentation of atrial fibrillation (OR 3.53), previous use of flecainide (OR 3.33) and left atrial diameter (OR 2.96) independently predicted occurrence of atrial fibrillation during the follow-up. A combination of pre- and intra-procedural documentation of atrial fibrillation (OR 3.81) and previous use of flecainide (OR 2.43) independently predicted additional atrial fibrillation ablation. Atrial fibrillation occurred in the majority of patients after ablation for typical atrial flutter and 42% of them required an additional dedicated ablation procedure. Pre- and intraprocedural documentation of atrial fibrillation together with previous use of flecainide independently predicted atrial fibrillation occurrence and a need for additional ablation. Anticoagulation treatment should be continued in high-risk patients in spite of clinical disappearance of atrial flutter.

  6. Response of atrial flutter to overdrive atrial pacing and intravenous disopyramide phosphate, singly and in combination.

    Science.gov (United States)

    Camm, J; Ward, D; Spurrell, R

    1980-01-01

    Ten patients who suffered spontaneous paroxysms of atrial flutter were investigated by electrophysiological techniques. Two had overt Wolff-Parkinson-White syndrome; three Lown-Ganong-Levine syndrome; and one a concealed accessory atrioventricular connection. Atrial flutter was initiated, at study, by right atrial pacing and electrograms from the right atrium and coronary sinus were observed for at least five minutes to ensure stable flutter in both atria. Atrial flutter was terminated by 2.5 s or 5 s bursts of atrial pacing at rates 10, 50, or 100 beats/min faster than the intrinsic flutter rate in only two patients. Atrial flutter, which was reinitiated in two patients, was then treated with intravenous disopyramide phosphate, 2 mg/kg body weight, infused over five minutes. In all 10 patients the atrial rate slowed from a mean of 310 +/- 39 beats/min to 217 +/- 27 beats/min and atrial flutter terminated in one case. Though the mean ventricular rate fell from 161 +/- 52 beats/min to 156 +/- 45 beats/min the atrioventricular conduction ratio fell from 2.17 +/- 0.86 to 1.55 +/- 0.59 and four patients were left with symptomatically significant increases of ventricular rate. In seven of nine patients overdrive atrial pacing, repeated after disopryamide, resulted in the conversion of atrial flutter to sinus rhythm. In this study, overdrive atrial pacing and intravenous disopyramide, singly and in combination, terminated atrial flutter in nine of the 10 patients and it is suggested that this method may provide an effective alternative to direct current cardioversion. PMID:7426181

  7. The circadian variation of premature atrial contractions

    DEFF Research Database (Denmark)

    Larsen, Bjørn Strøier; Kumarathurai, Preman; Nielsen, Olav W

    2016-01-01

    AIMS: The aim of the study was to assess a possible circadian variation of premature atrial contractions (PACs) in a community-based population and to determine if the daily variation could be used to assess a more vulnerable period of PACs in predicting later incidence of atrial fibrillation (AF...... variation in heart rate. After adjusting for relevant risk factors, the risk of AF was equal in all time intervals throughout the day. CONCLUSION: Premature atrial contractions showed a circadian variation in subjects with frequent PACs. No specific time interval of the day was more predictive of AF than...

  8. Contemporary Atrial Fibrillation Management: A Comparison of the Current AHA/ACC/HRS, CCS, and ESC Guidelines.

    Science.gov (United States)

    Andrade, Jason G; Macle, Laurent; Nattel, Stanley; Verma, Atul; Cairns, John

    2017-08-01

    In this article we compare and contrast the current recommendations, and highlight the important differences, in the American College of Cardiology/American Heart Association/Heart Rhythm Society, European Society of Cardiology, and Canadian Cardiovascular Society atrial fibrillation (AF) guidelines. Although many of the recommendations of the various societies are similar, there are important differences in the methodologies underlying their development and the specific content. Specifically, key differences can be observed in: (1) the definition of nonvalvular AF, which subsequently affects anticoagulation choices and candidacy for non-vitamin K antagonist oral anticoagulants; (2) the symptom score used to guide management decisions and longitudinal patient profiling; (3) the stroke risk stratification algorithm used to determine indications for oral anticoagulant therapy; (4) the role of acetylsalicylic acid in stroke prevention in AF; (5) the antithrombotic regimens used in the context of coronary artery disease, acute coronary syndromes, and percutaneous coronary intervention; (6) the rate control target and medications recommended to achieve the target; and (7) the role of "first-line" catheter ablation, open surgical ablation, and left atrial appendage exclusion. Copyright © 2017 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  9. Dynamic approximate entropy electroanatomic maps detect rotors in a simulated atrial fibrillation model.

    Science.gov (United States)

    Ugarte, Juan P; Orozco-Duque, Andrés; Tobón, Catalina; Kremen, Vaclav; Novak, Daniel; Saiz, Javier; Oesterlein, Tobias; Schmitt, Clauss; Luik, Armin; Bustamante, John

    2014-01-01

    There is evidence that rotors could be drivers that maintain atrial fibrillation. Complex fractionated atrial electrograms have been located in rotor tip areas. However, the concept of electrogram fractionation, defined using time intervals, is still controversial as a tool for locating target sites for ablation. We hypothesize that the fractionation phenomenon is better described using non-linear dynamic measures, such as approximate entropy, and that this tool could be used for locating the rotor tip. The aim of this work has been to determine the relationship between approximate entropy and fractionated electrograms, and to develop a new tool for rotor mapping based on fractionation levels. Two episodes of chronic atrial fibrillation were simulated in a 3D human atrial model, in which rotors were observed. Dynamic approximate entropy maps were calculated using unipolar electrogram signals generated over the whole surface of the 3D atrial model. In addition, we optimized the approximate entropy calculation using two real multi-center databases of fractionated electrogram signals, labeled in 4 levels of fractionation. We found that the values of approximate entropy and the levels of fractionation are positively correlated. This allows the dynamic approximate entropy maps to localize the tips from stable and meandering rotors. Furthermore, we assessed the optimized approximate entropy using bipolar electrograms generated over a vicinity enclosing a rotor, achieving rotor detection. Our results suggest that high approximate entropy values are able to detect a high level of fractionation and to locate rotor tips in simulated atrial fibrillation episodes. We suggest that dynamic approximate entropy maps could become a tool for atrial fibrillation rotor mapping.

  10. Increasing Prevalence of Atrial Fibrillation and Permanent Atrial Arrhythmias in Congenital Heart Disease.

    Science.gov (United States)

    Labombarda, Fabien; Hamilton, Robert; Shohoudi, Azadeh; Aboulhosn, Jamil; Broberg, Craig S; Chaix, Marie A; Cohen, Scott; Cook, Stephen; Dore, Annie; Fernandes, Susan M; Fournier, Anne; Kay, Joseph; Macle, Laurent; Mondésert, Blandine; Mongeon, François-Pierre; Opotowsky, Alexander R; Proietti, Anna; Rivard, Lena; Ting, Jennifer; Thibault, Bernard; Zaidi, Ali; Khairy, Paul

    2017-08-15

    Atrial arrhythmias are the most common complication encountered in the growing and aging population with congenital heart disease. This study sought to assess the types and patterns of atrial arrhythmias, associated factors, and age-related trends. A multicenter cohort study enrolled 482 patients with congenital heart disease and atrial arrhythmias, age 32.0 ± 18.0 years, 45.2% female, from 12 North American centers. Qualifying arrhythmias were classified by a blinded adjudicating committee. The most common presenting arrhythmia was intra-atrial re-entrant tachycardia (IART) (61.6%), followed by atrial fibrillation (28.8%), and focal atrial tachycardia (9.5%). The proportion of arrhythmias due to IART increased with congenital heart disease complexity from 47.2% to 62.1% to 67.0% in patients with simple, moderate, and complex defects, respectively (p = 0.0013). Atrial fibrillation increased with age to surpass IART as the most common arrhythmia in those ≥50 years of age (51.2% vs. 44.2%; p heart disease, with a predominantly paroxysmal pattern. However, atrial fibrillation increases in prevalence and atrial arrhythmias progressively become permanent as the population ages. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  11. Towards Low Energy Atrial Defibrillation

    Directory of Open Access Journals (Sweden)

    Philip Walsh

    2015-09-01

    Full Text Available A wireless powered implantable atrial defibrillator consisting of a battery driven hand-held radio frequency (RF power transmitter (ex vivo and a passive (battery free implantable power receiver (in vivo that enables measurement of the intracardiac impedance (ICI during internal atrial defibrillation is reported. The architecture is designed to operate in two modes: Cardiac sense mode (power-up, measure the impedance of the cardiac substrate and communicate data to the ex vivo power transmitter and cardiac shock mode (delivery of a synchronised very low tilt rectilinear electrical shock waveform. An initial prototype was implemented and tested. In low-power (sense mode, >5 W was delivered across a 2.5 cm air-skin gap to facilitate measurement of the impedance of the cardiac substrate. In high-power (shock mode, >180 W (delivered as a 12 ms monophasic very-low-tilt-rectilinear (M-VLTR or as a 12 ms biphasic very-low-tilt-rectilinear (B-VLTR chronosymmetric (6ms/6ms amplitude asymmetric (negative phase at 50% magnitude shock was reliably and repeatedly delivered across the same interface; with >47% DC-to-DC (direct current to direct current power transfer efficiency at a switching frequency of 185 kHz achieved. In an initial trial of the RF architecture developed, 30 patients with AF were randomised to therapy with an RF generated M-VLTR or B-VLTR shock using a step-up voltage protocol (50–300 V. Mean energy for successful cardioversion was 8.51 J ± 3.16 J. Subsequent analysis revealed that all patients who cardioverted exhibited a significant decrease in ICI between the first and third shocks (5.00 Ω (SD(σ = 1.62 Ω, p < 0.01 while spectral analysis across frequency also revealed a significant variation in the impedance-amplitude-spectrum-area (IAMSA within the same patient group (|∆(IAMSAS1-IAMSAS3[1 Hz − 20 kHz] = 20.82 Ω-Hz (SD(σ = 10.77 Ω-Hz, p < 0.01; both trends being absent in all patients that failed to cardiovert

  12. Atrial Fibrillation During an Exploration Class Mission

    Science.gov (United States)

    Lipsett, Mark; Hamilton, Douglas; Lemery, Jay; Polk, James

    2011-01-01

    This slide presentation reviews a possible scenario of an astronaut having Atrial Fibrillation during a Mars Mission. In the case review the presentation asks several questions about the alternatives for treatment, medications and the ramifications of the decisions.

  13. POSTOPERATIVE ATRIAL FIBRILLATION – AN UPDATE

    Directory of Open Access Journals (Sweden)

    Johnson Francis

    2015-12-01

    Full Text Available Atrial fibrillation is the most common perioperative cardiac arrhythmia. Sympathetic overactivity, inflammatory state and oxidative stress are important contributors to the genesis of postoperative atrial fibrillation. Advancing age and mitral valve disease along with left atrial size are important parameters in noted in multivariate prediction model. Genetic predisposition has also been noted. Preventive strategies tried include beta blockers, statins, posterior pericardiotomy, carperitide infusion and thoracic epidural analgesia. Treatment options include rate and rhythm control along with anticoagulation if it persists more than 48 hours with high CHADS2 score. Some of the therapeutic modalities which have been found to be NOT useful in preventing post operative atrial fibrillation are dexamethasone, magnesium infusion and concomitant pulmonary vein isolation.

  14. Atrial Fibrillation and Stroke in Elderly Patients

    Directory of Open Access Journals (Sweden)

    Geetanjali Dang

    2016-11-01

    Full Text Available The increasing prevalence of stroke, with an estimated annual cost of $71.5 billion, has made it a major health problem that increases disability and death, particularly in patients with atrial fibrillation. Although advanced age and atrial fibrillation are recognized as strong risk factors for stroke, the basis for this susceptibility are not well defined. Aging or associated diseases are accompanied by changes in rheostatic, humoral, metabolic and hemodynamic factors that may contribute more to stroke predisposition than rhythm abnormality alone. Several thromboembolism-predisposing clinical characteristics and serum biomarkers with prognostic significance have been identified in patients with atrial fibrillation. Although anticoagulation decreases the risk of thromboembolism, management in the elderly remains complex due to major concerns about bleeding. New anticoagulants and nonpharmacologic strategies are helpful to reduce the risk of bleeding, particularly in older-elderly patients. Herein, we review the pathogenesis and management of select issues of thromboembolism in the elderly with atrial fibrillation.

  15. [Cardiac rehabilitation in patients with atrial fibrillation].

    Science.gov (United States)

    Schlitt, Axel; Kamke, Wolfram; Guha, Manju; Haberecht, Olaf; Völler, Heinz

    2015-06-01

    The course of cardiac rehabilitation is often altered due to episodes of paroxysmal, predominantly postoperative atrial fibrillation. In symptomatic patients, a TEE-guided cardioversion - preferential DC shock - is indicated. In patients with persistent / permanent atrial fibrillation, a heart rate up to 110 / min and 170 / min at rest and during physical activity should, respectively, be tolerated. Therefore, training should not be quitted by heart rate but rather by load. The antithrombotic management is in addition a great task in treating patients with atrial fibrillation. With the exception of patients with a CHA2DS2-VASc-Score < 1, oral anticoagulation is indicated. Atrial fibrillation has little impact on social aspects, whereas the underlying heart disease and drug treatment (oral anticoagulation) has an important impact.

  16. Alcohol consumption and risk of atrial fibrillation

    DEFF Research Database (Denmark)

    Tolstrup, Janne Schurmann; Wium-Andersen, Marie Kim; Ørsted, David Dynnes

    2016-01-01

    BACKGROUND: The aim of this study was to test the hypothesis that alcohol consumption, both observational (self-reported) and estimated by genetic instruments, is associated with a risk of atrial fibrillation and to determine whether people with high cardiovascular risk are more sensitive towards...... register. As a measure of alcohol exposure, both self-reported consumption and genetic variations in alcohol metabolizing genes (ADH1B/ADH1C) were used as instrumental variables. The endpoint was admission to hospital for atrial fibrillation as recorded in a validated hospital register. RESULTS: A total...... of 3493 cases of atrial fibrillation occurred during follow-up. High alcohol consumption was associated with a risk of atrial fibrillation among men, but not among women. Among the men who drank 28-35 and 35+ drinks/week, the hazards ratios were 1.40 (95% confidence interval 1.09-1.80) and 1.62 (95...

  17. Isolamento das veias pulmonares em pacientes com fibrilação atrial permanente secundária a valvopatia mitral Isolation of the pulmonary veins in patients with permanent atrial fibrillation secondary to mitral valve disease

    Directory of Open Access Journals (Sweden)

    Gustavo G. Lima

    2004-04-01

    atrial appendage, and a perpendicular incision originating in the inferior margin of the circumferential incision isolating the pulmonary veins down to the mitral valve. Early arrhythmias were aggressively treated with cardioversion. RESULTS: The mean follow-up was 23.9±17 months, and 3 patients died in the postoperative period. Ten patients required electrical cardioversion in the postoperative period; 87% had sinus rhythm in the last medical visit, and 33% were using amiodarone. CONCLUSION: Isolation of the pulmonary veins associated with mitral valve surgery is an effective and safe technique for maintaining sinus rhythm in patients with permanent atrial fibrillation.

  18. The chemosensory appendage proteome of Amblyomma americanum (Acari: Ixodidae) reveals putative odorant-binding and other chemoreception-related proteins

    Science.gov (United States)

    Proteomic analyses were done on 2 chemosensory appendages of the lone star tick, Amblyomma americanum. Proteins in the fore tarsi, which contain the olfactory Haller's organ, and in the palps, that include gustatory sensilla, were compared with proteins in the third tarsi. Also, male and female tick...

  19. Three-dimensionally pre