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Sample records for fractionated atrial electrograms

  1. A new approach to automated assessment of fractionation of endocardial electrograms during atrial fibrillation

    International Nuclear Information System (INIS)

    Křemen, V; Lhotská, L; Macaš, M; Čihák, R; Vančura, V; Kautzner, J; Wichterle, D

    2008-01-01

    Complex fractionated atrial electrograms (CFAEs) may represent the electrophysiological substrate for atrial fibrillation (AF). Progress in signal processing algorithms to identify sites of CFAEs is crucial for the development of AF ablation strategies. A novel algorithm for automated description of fractionation of atrial electrograms (A-EGMs) based on the wavelet transform has been proposed. The algorithm was developed and validated using a representative set of 1.5 s A-EGM (n = 113) ranked by three experts into four categories: 1—organized atrial activity; 2—mild; 3—intermediate; 4—high degree of fractionation. A tight relationship between a fractionation index and expert classification of A-EGMs (Spearman correlation ρ = 0.87) was documented with a sensitivity of 82% and specificity of 90% for the identification of highly fractionated A-EGMs. This operator-independent description of A-EGM complexity may be easily incorporated into mapping systems to facilitate CFAE identification and to guide AF substrate ablation

  2. Characteristics of complex fractionated atrial electrogram in the electroanatomically remodeled left atrium of patients with atrial fibrillation

    International Nuclear Information System (INIS)

    Park, Jae-Hyung; Kim, Jong-Youn; Park, Sang-Weon

    2010-01-01

    Complex fractionated atrial electrogram (CFAE) guided ablation is effective in some patients with persistent atrial fibrillation (PeAF), but the pattern of CFAE may be different in the remodeled left atrium (LA). In 100 AF patients (83 males, 55.0±10.6 years old) with AF (51 paroxysmal AF (PAF), 49 PeAF) who underwent catheter ablation, CFAE cycle length (CL) and distribution (NavX 3D map) were compared according to the LA volume (3D-CT) and endocardial voltage (during high right atrial pacing 500-ms (Vol PACE ) and AF (Vol AF ; NavX). The mean CFAE-CL was longer (P=0.003) and the % area CFAE was smaller (P=0.006) in patients with LA ≥125 ml than those with PACE AF PACE <1.7 mV than those with ≥1.7 mV (P=0.006). The incidence of septal CFAE was consistently high, regardless of the degree of LA remodeling. In the AF patients with an electroanatomically remodeled LA, the % area of CFAE was smaller and mean CFAE-CL was longer than in those with a less remodeled LA. However, the majority of CFAE are consistently positioned on the septum in the remodeled LA. (author)

  3. Unipolar atrial electrogram morphology from an epicardial and endocardial perspective.

    Science.gov (United States)

    van der Does, Lisette J M E; Knops, Paul; Teuwen, Christophe P; Serban, Corina; Starreveld, Roeliene; Lanters, Eva A H; Mouws, Elisabeth M J P; Kik, Charles; Bogers, Ad J J C; de Groot, Natasja M S

    2018-02-22

    Endo-epicardial asynchrony (EEA) and the interplay between the endocardial and epicardial layers could be important in the pathophysiology of atrial arrhythmias. The morphologic differences between epicardial and endocardial atrial electrograms have not yet been described, and electrogram morphology may hold information about the presence of EEA. The purpose of this study was to directly compare epicardial to endocardial unipolar electrogram morphology during sinus rhythm (SR) and to evaluate whether EEA contributes to electrogram fractionation by correlating fractionation to spatial activation patterns. In 26 patients undergoing cardiac surgery, unipolar electrograms were simultaneously recorded from the epicardium and endocardium at the inferior, middle, and superior right atrial (RA) free wall during SR. Potentials were analyzed for epi-endocardial differences in local activation time, voltage, RS ratio, and fractionation. The surrounding and opposite electrograms of fractionated deflections were evaluated for corresponding local activation times in order to determine whether fractionation originated from EEA. The superior RA was predisposed to delayed activation, EEA, and fractionation. Both epicardial and endocardial electrograms demonstrated an S-predominance. Fractionation was mostly similar between the 2 sides; however, incidentally deflections up to 4 mV on 1 side could be absent on the other side. Remote activation was responsible for most fractionated deflections (95%) in SR, of which 4% could be attributed to EEA. Local epi-endocardial differences in electrogram fractionation occur occasionally during SR but will likely increase during arrhythmias due to increasing EEA and (functional) conduction disorders. Electrogram fractionation can originate from EEA, and this study demonstrated that unipolar electrogram fractionation can potentially identify EEA. Copyright © 2018 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  4. Atrial electrogram interpretation improves after an innovative education program.

    Science.gov (United States)

    Preston, Julie L; Currey, Judy; Considine, Julie

    2015-01-01

    To avoid adverse patient outcomes from inappropriate treatment, it is recommended that an atrial electrogram (AEG) be recorded whenever atrial arrhythmias develop in patients after cardiac surgery. However, AEGs are not commonly performed because nurses lack knowledge about differentiating atrial rhythms on AEGs. To investigate whether completing a novel online evidence-based education program on interpreting AEGs would improve critical care nurses' AEG interpretation. Specialized critical care nurses were taught about obtaining and interpreting atrial rhythms on AEGs using a 42-minute online mini-movie. AEG interpretation was assessed pre and two and eight weeks post-intervention. AEG interpretation increased two weeks post intervention and was retained at eight weeks. Some participants used this newly acquired knowledge to interpret arrhythmias that were not taught during the education program. Accurate interpretation of AEGs is an easy skill for specialized critical care nurses to learn via an online education program.

  5. Automatic detection and classification of human epicardial atrial unipolar electrograms

    International Nuclear Information System (INIS)

    Dubé, B; Vinet, A; Xiong, F; Yin, Y; LeBlanc, A-R; Pagé, P

    2009-01-01

    This paper describes an unsupervised signal processing method applied to three-channel unipolar electrograms recorded from human atria. These were obtained by epicardial wires sutured on the right and left atria after coronary artery bypass surgery. Atrial (A) and ventricular (V) activations had to be detected and identified on each channel, and gathered across the channels when belonging to the same global event. The algorithm was developed and optimized on a training set of 19 recordings of 5 min. It was assessed on twenty-seven 2 h recordings taken just before the onset of a prolonged atrial fibrillation for a total of 1593697 activations that were validated and classified as normal atrial or ventricular activations (A, V) and premature atrial or ventricular activations (PAA, PVA). 99.93% of the activations were detected, and amongst these, 99.89% of the A and 99.75% of the V activations were correctly labelled. In the subset of the 39705 PAA, 99.83% were detected and 99.3% were correctly classified as A. The false positive rate was 0.37%. In conclusion, a reliable fully automatic detection and classification algorithm was developed that can detect and discriminate A and V activations from atrial recordings. It can provide the time series needed to develop a monitoring system aiming to identify dynamic predictors of forthcoming cardiac events such as postoperative atrial fibrillation

  6. Validation of double-spike electrograms as markers of conduction delay or block in atrial flutter.

    Science.gov (United States)

    Cosio, F G; Arribas, F; Barbero, J M; Kallmeyer, C; Goicolea, A

    1988-04-01

    Recent mapping studies of atrial flutter have shown that fragmented electrograms can be found in most cases from the posterior, posteroseptal and posterolateral walls of the right atrium. The fragmentation pattern most often consists of a double spike. To further assess double-spike electrograms as a possible marker of conduction delay, bipolar electrograms were continuously recorded during atrial overdrive pacing of common flutter from the right atrium (7 patients) and from the proximal coronary sinus (5). Baseline double-spike separation of 50 to 130 ms was unchanged in 1 patient and slightly increased (5 to 25 ms) in 4 by coronary sinus pacing. The electrogram sequence was unchanged and the surface morphology was similar to that of basal flutter. Right atrial pacing decreased double-spike separation by 25 to 85 ms from basal values of 45 to 175 ms (23 to 83%), suggesting fusion in the area of fragmented electrograms. These findings suggest that double-spike electrograms represent activation on both sides of a conduction delay zone. The changes induced in these electrograms by pacing from the anterior right atrium and the coronary sinus are consistent with flutter circuits rotating counterclockwise (frontal plane) in the posterior right atrial wall in common atrial flutter.

  7. Assessment of non-invasive time and frequency atrial fibrillation organization markers with unipolar atrial electrograms

    International Nuclear Information System (INIS)

    Alcaraz, Raúl; Hornero, Fernando; Rieta, José J

    2011-01-01

    The standard electrocardiogram (ECG) is the most common non-invasive way to study atrial fibrillation (AF). In this respect, previous works have shown that the surface lead V 1 reflects mainly the dominant atrial frequency (DAF) of the right atrium (RA), which has been widely used to study AF. In a similar way, AF organization and fibrillatory (f) wave amplitude are two recently proposed non-invasive AF markers. These markers need to be validated with invasive recordings in order to assess their capability to reliably reflect the internal fibrillatory activity dynamics. In this work, these two non-invasive metrics have been compared with similar measures recorded from two unipolar atrial electrograms (AEGs). For both ECG and AEG signals, AF organization has been computed by applying a nonlinear regularity index, such as sample entropy (SampEn), to the atrial activity (AA) and to its fundamental waveform, defined as the main atrial wave (MAW). The surface and epicardial f wave amplitude has been estimated through their mean power. Results obtained for 38 patients showed statistically significant correlations between the values measured from surface and invasive recordings, thus corroborating the usefulness of the aforesaid markers in the non-invasive study of AF. Precisely, for AF organization computed from the MAW, the correlation coefficients between surface and both AEGs were R = 0.926 (p < 0.001) and R = 0.932 (p < 0.001). For f wave amplitude, slightly lower significant relationships were noticed, the correlation coefficients being R = 0.765 (p < 0.001) and R = 0.842 (p < 0.001). These outcomes together with interesting linear relationships found among the parameters suggest that AF regularity estimated via SampEn and f wave amplitude can non-invasively characterize the epicardial activity related to AF

  8. Ventricular activity cancellation in electrograms during atrial fibrillation with constraints on residuals' power.

    Science.gov (United States)

    Corino, Valentina D A; Rivolta, Massimo W; Sassi, Roberto; Lombardi, Federico; Mainardi, Luca T

    2013-12-01

    During atrial fibrillation (AF), cancellation of ventricular activity from atrial electrograms (AEG) is commonly performed by template matching and subtraction (TMS): a running template, built in correspondence of QRSs, is subtracted from the AEG to uncover atrial activity (AA). However, TMS can produce poor cancellation, leaving high-power residues. In this study, we propose to modulate the templates before subtraction, in order to make the residuals as similar as possible to the nearby atrial activity, avoiding high-power ones. The coefficients used to modulate the template are estimated by maximizing, via Multi-swarm Particle Swarm Optimization, a fitness function. The modulated TMS method (mTMS) was tested on synthetic and real AEGs. Cancellation performances were assessed using: normalized mean squared error (NMSE, computed on simulated data only), reduction of ventricular activity (VDR), and percentage of segments (PP) whose power was outside the standard range of the atrial power. All testings suggested that mTMS is an improvement over TMS alone, being, on simulated data, NMSE and PP significantly decreased while VDR significantly increased. Similar results were obtained on real electrograms (median values of CS1 recordings PP: 2.44 vs. 0.38 p < 0.001; VDR: 6.71 vs. 8.15 p < 0.001). Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

  9. Atrial electrogram quality in single-pass defibrillator leads with floating atrial bipole in patients with permanent atrial fibrillation and cardiac resynchronization therapy.

    Science.gov (United States)

    Sticherling, Christian; Müller, Dirk; Schaer, Beat A; Krüger, Silke; Kolb, Christof

    2018-03-27

    Many patients receiving cardiac resynchronization therapy (CRT) suffer from permanent atrial fibrillation (AF). Knowledge of the atrial rhythm is important to direct pharmacological or interventional treatment as well as maintaining AV-synchronous biventricular pacing if sinus rhythm can be restored. A single pass single-coil defibrillator lead with a floating atrial bipole has been shown to obtain reliable information about the atrial rhythm but has never been employed in a CRT-system. The purpose of this study was to assess the feasibility of implanting a single coil right ventricular ICD lead with a floating atrial bipole and the signal quality of atrial electrograms (AEGM) in CRT-defibrillator recipients with permanent AF. Seventeen patients (16 males, mean age 73 ± 6 years, mean EF 25 ± 5%) with permanent AF and an indication for CRT-defibrillator placement were implanted with a designated CRT-D system comprising a single pass defibrillator lead with a atrial floating bipole. They were followed-up for 103 ± 22 days using remote monitoring for AEGM transmission. All patients had at last one AEGM suitable for atrial rhythm diagnosis and of 100 AEGM 99% were suitable for visual atrial rhythm assessment. Four patients were discharged in sinus rhythm and one reverted to AF during follow-up. Atrial electrograms retrieved from a single-pass defibrillator lead with a floating atrial bipole can be reliably used for atrial rhythm diagnosis in CRT recipients with permanent AF. Hence, a single pass ventricular defibrillator lead with a floating bipole can be considered in this population. Copyright © 2018 Indian Heart Rhythm Society. Production and hosting by Elsevier B.V. All rights reserved.

  10. Detecting phase singularities and rotor center trajectories based on the Hilbert transform of intraatrial electrograms in an atrial voxel model

    Directory of Open Access Journals (Sweden)

    Unger Laura Anna

    2015-09-01

    Full Text Available This work aimed at the detection of rotor centers within the atrial cavity during atrial fibrillation on the basis of phase singularities. A voxel based method was established which employs the Hilbert transform and the phase of unipolar electrograms. The method provides a 3D overview of phase singularities at the endocardial surface and within the blood volume. Mapping those phase singularities from the inside of the atria at the endocardium yielded rotor center trajectories. We discuss the results for an unstable and a more stable rotor. The side length of the areas covered by the trajectories varied from 1.5 mm to 10 mm. These results are important for cardiologists who target rotors with RF ablation in order to cure atrial fibrillation.

  11. Machine learning methods for locating re-entrant drivers from electrograms in a model of atrial fibrillation

    Science.gov (United States)

    McGillivray, Max Falkenberg; Cheng, William; Peters, Nicholas S.; Christensen, Kim

    2018-04-01

    Mapping resolution has recently been identified as a key limitation in successfully locating the drivers of atrial fibrillation (AF). Using a simple cellular automata model of AF, we demonstrate a method by which re-entrant drivers can be located quickly and accurately using a collection of indirect electrogram measurements. The method proposed employs simple, out-of-the-box machine learning algorithms to correlate characteristic electrogram gradients with the displacement of an electrogram recording from a re-entrant driver. Such a method is less sensitive to local fluctuations in electrical activity. As a result, the method successfully locates 95.4% of drivers in tissues containing a single driver, and 95.1% (92.6%) for the first (second) driver in tissues containing two drivers of AF. Additionally, we demonstrate how the technique can be applied to tissues with an arbitrary number of drivers. In its current form, the techniques presented are not refined enough for a clinical setting. However, the methods proposed offer a promising path for future investigations aimed at improving targeted ablation for AF.

  12. Influence of detomidine on atrial fibrillation cycle length measured by intracardiac electrogram recording and by colour tissue Doppler imaging in horses.

    Science.gov (United States)

    Decloedt, A; de Clercq, D; van der Vekens, N; Verheyen, T; Ven, S; van Loon, G

    2016-01-01

    Shortening of atrial fibrillation cycle length (AFCL) is a marker of atrial electrical remodelling due to atrial fibrillation (AF). To investigate the effect of administration of detomidine on AFCL measured invasively from an intra-atrial electrogram (AFCLEGM) and noninvasively by tissue Doppler imaging (AFCLTDI). We hypothesised that detomidine would have no effect on AFCL but would improve the ease of TDI measurements and facilitate noninvasive AFCL determination. Prospective clinical study. Measurements were performed before and after i.v. administration of 7.5 μg/kg bwt detomidine in 33 episodes of AF in 32 horses (582 ± 64 kg bwt, 10 ± 3 years old) referred for electrical cardioversion. The AFCLEGM was measured from a right atrial intracardiac electrogram. The AFCLTDI was measured from atrial colour tissue velocity curves in 5 atrial wall regions. Mean AFCLEGM and AFCLTDI without and with sedation were compared using a repeated-measures linear mixed model with Bonferroni correction for multiple comparisons and calculation of the Bland-Altman mean bias and limits of agreement between AFCLEGM and AFCLTDI. The mean AFCL was significantly increased after sedation, but this increase was very small (mean difference +4 ms). For AFCLTDI measurements, sedation significantly improved the quality of the atrial myocardial velocity curves and the number of AF cycles that could be measured per cardiac cycle. The Bland-Altman bias between AFCLEGM without sedation and AFCLTDI with sedation ranged from -18 to +15 ms depending on wall region. Bland-Altman limits of agreement were similar between AFCLEGM without sedation and AFCLTDI without and with sedation. Therefore, noninvasive AFCLTDI measurements with sedation can be used to estimate the atrial fibrillatory rate. Sedation facilitates noninvasive AFCL measurements but causes a slight increase in AFCL. Noninvasive AFCL measurements can be used as an indicator of atrial electrical remodelling, to study AF

  13. 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

  14. 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.

  15. 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. PMID:25489858

  16. Aspectos técnicos da cateterização do seio coronariano baseada no componente atrial do eletrograma intracavitário e anatomia radiológica durante o procedimento de implante de marcapasso biventricular Technical aspects of coronary sinus catheterization based on the atrial component of the intracavitary electrogram and radiological anatomy during the implantation procedure of a biventricular pacemaker

    Directory of Open Access Journals (Sweden)

    Fernando Sérgio Oliva de Souza

    2006-04-01

    Full Text Available OBJETIVO: Apresentar uma proposição técnica baseada na experiência de 130 implantes utilizando técnica simplificada para cateterização do seio coronariano, baseada no componente atrial do eletrograma intracavi-tário e anatomia radiológica. MÉTODOS: De outubro de 2001 a outubro de 2004 foram realiza-dos 130 implantes de marcapasso biventricular, utilizando-se anatomia radiológica e observação de eletrograma intracavitário, com prioridade ao componente atrial. RESULTADOS: O implante do sistema, utilizando-se a estimulação do ventrículo esquerdo via seio coronariano, não foi possível em 8 pacientes. Em 12 pacientes foram observadas dificuldades na canulação do óstio coronário e em 15 pacientes observaram-se dificuldades de progressão do eletrodo através do seio coronariano. O tempo médio de utilização de radioscopia foi de 18,69 min. CONCLUSÃO: A técnica de implante, utilizando a morfologia do componente atrial do eletrograma intracavitário e anatomia radiológica, demonstrou ser pouco trabalhosa, segura e eficaz para canulação do óstio do seio coronariano, necessitando de reduzido tempo de radioscopia.OBJECTIVE: To present a technical proposal based on the experience of 130 implantations using a simplified technique for coronary sinus catheterization, based on the atrial component of the intracavitary electrogram and radiological anatomy. METHODS: From October, 2001 to October, 2004, 130 biventricular pacemaker implantations were performed, using radiological anatomy and observation of the intracavitary electrogram, focusing on the atrial component. RESULTS: The implantation of the system using left ventricular pacing via coronary sinus was not possible in 8 patients. Difficulties on the cannulation of the coronary ostium were felt in 12 patients and difficulties of lead advancement through the coronary sinus were felt in 15 patients. The mean time of radioscopy utilization was 18.69 min. CONCLUSION: The

  17. Left atrial function in heart failure with impaired and preserved ejection fraction.

    Science.gov (United States)

    Fang, Fang; Lee, Alex Pui-Wai; Yu, Cheuk-Man

    2014-09-01

    Left atrial structural and functional changes in heart failure are relatively ignored parts of cardiac assessment. This review illustrates the pathophysiological and functional changes in left atrium in heart failure as well as their prognostic value. Heart failure can be divided into those with systolic dysfunction and heart failure with preserved ejection fraction (HFPEF). Left atrial enlargement and dysfunction commonly occur in systolic heart failure, in particular, in idiopathic dilated cardiomyopathy. Atrial enlargement and dysfunction also carry important prognostic value in systolic heart failure, independently of known parameters such as left ventricular ejection fraction. In HFPEF, there is evidence of left atrial enlargement, impaired atrial compliance, and reduction of atrial pump function. This occurs not only at rest but also during exercise, indicating significant impairment of atrial contractile reserve. Furthermore, atrial dyssynchrony is common in HFPEF. These factors further contribute to the development of new onset or progression of atrial arrhythmias, in particular, atrial fibrillation. Left atrial function is an integral part of cardiac function and its structural and functional changes in heart failure are common. As changes of left atrial structure and function have different clinical implications in systolic heart failure and HFPEF, routine assessment is warranted.

  18. A new LMS algorithm for analysis of atrial fibrillation signals

    OpenAIRE

    Ciaccio Edward J; Biviano Angelo B; Whang William; Garan Hasan

    2012-01-01

    Abstract Background A biomedical signal can be defined by its extrinsic features (x-axis and y-axis shift and scale) and intrinsic features (shape after normalization of extrinsic features). In this study, an LMS algorithm utilizing the method of differential steepest descent is developed, and is tested by normalization of extrinsic features in complex fractionated atrial electrograms (CFAE). Method Equations for normalization of x-axis and y-axis shift and scale are first derived. The algori...

  19. Electrograms (ECG, EEG, EMG, EOG).

    Science.gov (United States)

    Reilly, Richard B; Lee, T Clive

    2010-01-01

    There is a constant need in medicine to obtain objective measurements of physical and cognitive function as the basis for diagnosis and monitoring of health. The body can be considered as a chemical and electrical system supported by a mechanical structure. Measuring and quantifying such electrical activity provides a means for objective examination of heath status. The term electrogram, from the Greek electro meaning electricity and gram meaning write or record, is the broad definition given to the recording of electrical signal from the body. In order that comparisons of electrical activity can be made against normative data, certain methods and procedures have been defined for different electrograms. This paper reviews these methods and procedures for the more typical electrograms associated with some of the major organs in the body, providing a first point of reference for the reader.

  20. Ejection fraction and outcomes in patients with atrial fibrillation and heart failure

    DEFF Research Database (Denmark)

    Banerjee, Amitava; Taillandier, Sophie; Olesen, Jonas Bjerring

    2012-01-01

    Heart failure (HF) increases the risk of stroke and thrombo-embolism (TE) in non-valvular atrial fibrillation (NVAF), and is incorporated in stroke risk stratification scores. We aimed to establish the role of ejection fraction (EF) in risk prediction in patients with NVAF and HF.......Heart failure (HF) increases the risk of stroke and thrombo-embolism (TE) in non-valvular atrial fibrillation (NVAF), and is incorporated in stroke risk stratification scores. We aimed to establish the role of ejection fraction (EF) in risk prediction in patients with NVAF and HF....

  1. A novel intra-operative, high-resolution atrial mapping approach.

    Science.gov (United States)

    Yaksh, Ameeta; van der Does, Lisette J M E; Kik, Charles; Knops, Paul; Oei, Frans B S; van de Woestijne, Pieter C; Bekkers, Jos A; Bogers, Ad J J C; Allessie, Maurits A; de Groot, Natasja M S

    2015-12-01

    A new technique is demonstrated for extensive high-resolution intra-operative atrial mapping that will facilitate the localization of atrial fibrillation (AF) sources and identification of the substrate perpetuating AF. Prior to the start of extra-corporal circulation, a 8 × 24-electrode array (2-mm inter-electrode distance) is placed subsequently on all the right and left epicardial atrial sites, including Bachmann's bundle, for recording of unipolar electrograms during sinus rhythm and (induced) AF. AF is induced by high-frequency pacing at the right atrial free wall. A pacemaker wire stitched to the right atrium serves as a reference signal. The indifferent pole is connected to a steal wire fixed to subcutaneous tissue. Electrograms are recorded by a computerized mapping system and, after amplification (gain 1000), filtering (bandwidth 0.5-400 Hz), sampling (1 kHz) and analogue to digital conversion (16 bits), automatically stored on hard disk. During the mapping procedure, real-time visualization secures electrogram quality. Analysis will be performed offline. This technique was performed in 168 patients of 18 years and older, with coronary and/or structural heart disease, with or without AF, electively scheduled for cardiac surgery and a ventricular ejection fraction above 40 %. The mean duration of the entire mapping procedure including preparation time was 9 ± 2 min. Complications related to the mapping procedure during or after cardiac surgery were not observed. We introduce the first epicardial atrial mapping approach with a high resolution of ≥1728 recording sites which can be performed in a procedure time of only 9±2 mins. This mapping technique can potentially identify areas responsible for initiation and persistence of AF and hopefully can individualize both diagnosis and therapy of AF.

  2. II.3. Electrograms (ECG, EEG, EMG, EOG).

    Science.gov (United States)

    Reilly, Richard B; Lee, T Clive

    2010-01-01

    There is a constant need in medicine to obtain objective measurements of physical and cognitive function as the basis for diagnosis and monitoring of health. The body can be considered as a chemical and electrical system supported by a mechanical structure. Measuring and quantifying such electrical activity provides a means for objective examination of heath status. The term electrogram, from the Greek electro meaning electricity and gram meaning write or record, is the broad definition given to the recording of electrical signal from the body. In order that comparisons of electrical activity can be made against normative data, certain methods and procedures have been defined for different electrograms. This paper reviews these methods and procedures for the more typical electrograms associated with some of the major organs in the body, providing a first point of reference for the reader.

  3. The biological and immunological properties of fractionated atrial extracts from young and old rats

    International Nuclear Information System (INIS)

    Wilfinger, W.W.; Banks, R.O.; Inscho, E.W.

    1989-01-01

    The present study was undertaken to further evaluate the natriuretic, hypotensive and immunological properties of fractionated and HPLC purified atrial extracts prepared from young and old rats. Acetic acid extracts were prepared and subsequently fractionated by gel permeation chromatography. The high and low molecular weight fractions were collected, lyophilized and assayed. Radioimmunoassay competitive binding curves of the initial and fractionated extracts were parallel to the synthetic ANP 101-126 standard. No differences in parallelism were observed in the natriuretic activity of the initial extracts, the low molecular weight (LMW) fractions from both age groups, the 290 day high molecular weight (HMW) fraction or the synthetic ANP standard. However, the natriuretic activity of the 15 day HMW fraction was significantly attenuated compared to the other treatment groups. The initial 15 day extract was also significantly more hypotensive than the 290 day extract. HMW extracts were subjected to HPLC and the resulting immunoreactive ANP peak was reassayed. Based on SDS-PAGE and immuno blot analysis, the HPLC purified fraction was found to contain only immunoreactive proANP. Subsequent bioassay revealed greater hypotension and reduced natriuretic activity in the 15 day proANP fraction in comparison to a similarly prepared extract from older animals

  4. The importance of integrated left atrial evaluation: From hypertension to heart failure with preserved ejection fraction.

    Science.gov (United States)

    Beltrami, Matteo; Palazzuoli, Alberto; Padeletti, Luigi; Cerbai, Elisabetta; Coiro, Stefano; Emdin, Michele; Marcucci, Rossella; Morrone, Doralisa; Cameli, Matteo; Savino, Ketty; Pedrinelli, Roberto; Ambrosio, Giuseppe

    2018-02-01

    Functional analysis and measurement of left atrium are an integral part of cardiac evaluation, and they represent a key element during non-invasive analysis of diastolic function in patients with hypertension (HT) and/or heart failure with preserved ejection fraction (HFpEF). However, diastolic dysfunction remains quite elusive regarding classification, and atrial size and function are two key factors for left ventricular (LV) filling evaluation. Chronic left atrial (LA) remodelling is the final step of chronic intra-cavitary pressure overload, and it accompanies increased neurohormonal, proarrhythmic and prothrombotic activities. In this systematic review, we aim to purpose a multi-modality approach for LA geometry and function analysis, which integrates diastolic flow with LA characteristics and remodelling through application of both traditional and new diagnostic tools. The most important studies published in the literature on LA size, function and diastolic dysfunction in patients with HFpEF, HT and/or atrial fibrillation (AF) are considered and discussed. In HFpEF and HT, pulsed and tissue Doppler assessments are useful tools to estimate LV filling pressure, atrio-ventricular coupling and LV relaxation but they need to be enriched with LA evaluation in terms of morphology and function. An integrated evaluation should be also applied to patients with a high arrhythmic risk, in whom eccentric LA remodelling and higher LA stiffness are associated with a greater AF risk. Evaluation of LA size, volume, function and structure are mandatory in the management of patients with HT, HFpEF and AF. A multi-modality approach could provide additional information, identifying subjects with more severe LA remodelling. Left atrium assessment deserves an accurate study inside the cardiac imaging approach and optimised measurement with established cut-offs need to be better recognised through multicenter studies. © 2017 John Wiley & Sons Ltd.

  5. Value of local electrogram characteristics predicting successful catheter ablation of left-versus right-sided accessory atrioventricular pathways by radiofrequency current.

    Science.gov (United States)

    Lin, J L; Schie, J T; Tseng, C D; Chen, W J; Cheng, T F; Tsou, S S; Chen, J J; Tseng, Y Z; Lien, W P

    1995-01-01

    Despite similar guidance by local electrogram criteria, catheter ablation of right-sided accessory atrioventricular (AV) pathways by radiofrequency current has been less effective than that of left-sided ones. In order to elucidate the possible diversities in local electrosignal criteria, we systematically analyzed the morphological and timing characteristics of 215 bipolar local electrograms from catheter ablation sites of 65 left-sided accessory AV pathways and of 356 from those of 37 right-sided ones in 92 consecutive patients with Wolff-Parkinson-White syndrome or AV reentrant tachycardia incorporating concealed accessory AV pathways. After stepwise multivariate analysis, we selected the presence of a possible accessory pathway potential, local ventricular activation preceding QRS complex for 20 ms or more during ventricular insertion mapping, and the local retrograde ventriculoatrial (VA) continuity, local retrograde VA interval right-sided targets only) during atrial insertion mapping, as independent local electrogram predictors for successful ablation of left- and right-sided accessory AV pathways. Combination of all local electrogram predictors could have moderate chance of success (80 and 51%) for the ventricular and atrial insertion ablation of left-sided accessory AV pathways, but only low probability of success (40% in ventricular insertion ablation) or very low sensitivity (12.5% in atrial insertion ablation) for right-sided ones. In conclusion, with the present approach, successful catheter ablation of right-sided accessory AV pathways, compared to left-sided ones, still necessitate a breakthrough in the precision mapping and the efficiency of energy delivery.

  6. Current strategies for non-pharmacological therapy of long-standing persistent atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Teiichi Yamane, MD, PhD

    2012-06-01

    Full Text Available Non-pharmacological rhythm control of atrial fibrillation (AF is becoming increasingly important in our aging society. Advancement of catheter ablation techniques in the last decade has provided a cure for AF patients, with a nearly established efficiency for paroxysmal cases. However, since ablation of persistent/chronic AF cases is still challenging, early treatment of paroxysmal AF before transformation to the persistent/chronic form is mandatory. Although there is a consensus that pulmonary vein isolation is the first-line approach for ablation of long-standing persistent AF, similar to that for paroxysmal AF, there are still wide variations in the adjunctive approach to modify the atrial substrate of persistent AF (anatomical linear ablation, electrogram-based complex fractionated atrial electrogram ablation, ganglionated plexus ablation, etc.. Since data comparing the effectiveness of these adjunctive approaches are still lacking, large-scale controlled trials evaluating the effect of catheter ablation in diverse patient populations on a long-term basis are needed to establish the appropriate approach for long-standing persistent AF. Furthermore, the development of de novo ablation methods (new energies, new targets, etc. is expected to improve ablation outcome in patients with long-standing persistent AF.

  7. Clinical significance of right ventricular ejection fraction in cases with atrial septal defect

    Energy Technology Data Exchange (ETDEWEB)

    Hamada, Seiki; Nishimura, Tsunehiko; Hayashida, Kouhei; Uehara, Toshiisa

    1989-04-01

    Right ventricular ejection fraction (RVEF) assessed by cardiac radionuclide angiography has been applied to evaluate ventricular function such as ischemic, valvular and congenital heart disease. Using this modality, previous reports also suggest that there is good correlation between RVEF and mean pulmonary arterial pressure (mPA) from catheterization findings in mitral valvular disease and chronic obstructive lung disease. In this study, cardiac RI angiography were performed on 33 adult patients with atrial septal defect (ASD). RVEF is not so good correlation (r=-0.42) with mPA, but in cases within pulmonary to systemic ratio (Qp/Qs) less than 2.0 limits, there is good correlation between RVEF and mPA (n=9, r=-0.71). As a conclusion, in ASD, both afterload assessed by mPA and preload assessed by Qp/Qs decrease RVEF. (author).

  8. Atrial fibrillation in heart failure with preserved ejection fraction: Insights into mechanisms and therapeutics.

    Science.gov (United States)

    Patel, Ravi B; Vaduganathan, Muthiah; Shah, Sanjiv J; Butler, Javed

    2017-08-01

    Atrial fibrillation (AF) and heart failure (HF) often coexist, and the outcomes of patients who have both AF and HF are considerably worse than those with either condition in isolation. Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous clinical entity and accounts for approximately one-half of current HF. At least one-third of patients with HFpEF are burdened by comorbid AF. The current understanding of the relationship between AF and HFpEF is limited, but the clinical implications are potentially important. In this review, we explore 1) the pathogenesis that drives AF and HFpEF to coexist; 2) pharmacologic therapies that may attenuate the impact of AF in HFpEF; and 3) future directions in the management of this complex syndrome. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. 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); Patrial CFE area was reduced by LA ablation, from 25.9±14.1 to 12.9±11.8 cm(2) (Patrial 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.

  10. Positive predictive value of device-detected atrial high-rate episodes at different rates and durations

    DEFF Research Database (Denmark)

    Kaufman, Elizabeth S; Israel, Carsten W; Nair, Girish M

    2012-01-01

    BACKGROUND: Pacemakers can automatically identify and catalog atrial high-rate episodes (AHREs). While most AHREs represent true atrial tachyarrhythmia/atrial fibrillation (AT/AF), a review of stored electrograms suggests that a substantial proportion do not. As AHREs may lead to the initiation o...

  11. Influence of atrial fibrillation on the mortality of patients with heart failure with preserved ejection fraction.

    Science.gov (United States)

    Franco, Jonathan; Formiga, Francesc; Cepeda, Jose; Llacer, Pau; Arévalo-Lorido, Juan; Cerqueiro, Jose; González-Franco, Alvaro; Epelde, Francesc; Manzano, Luis; Montero Pérez-Barquero, Manuel

    2018-05-23

    The impact of atrial fibrillation (AF) on the prognosis of heart failure with preserved ejection fraction (HFpEF) is still the subject of debate. We analysed the influence of AF on the prognosis on mortality and readmission in patients with HFpEF. Prospective observational study in 1,971 patients with HFpEF, who were admitted for acute heart failure. Patients were divided into 2 groups according to the presence or absence of AF. We analysed mortality, readmissions and combined mortality/readmissions at one year follow-up. A total of 1,177 (59%) patients had AF, mean age 80.3 (7.8) years and 1,233 (63%) were women. Patients with HFpEF and AF were older, female, greater valvular aetiology and lower comorbidity measured by the Charlson index. At the one year follow-up, 430 (22%) patients had died and 840 (43%) had been readmitted. In the 2 groups analysed, there was no difference in all-cause mortality (22 vs. 21%; P=.739, AF vs. no-AF, respectively) or cardiovascular causes (9.6 vs. 8.2%; P=.739, AF vs. no-AF, respectively). In the multivariable analysis, factors associated with higher mortality were: age, male, valvular aetiology, uric acid, and comorbidity. In the analysis of the subgroup with HFpEF with AF, the presence of chronic AF compared to de novo AF was associated with higher mortality (HR 1,716; 95% CI 1,099-2,681; P=.018). In patients with HFpEF, the presence of AF is frequent. During the one-year follow-up, the presence of AF does not influence mortality or readmissions in patients with HFpEF. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  12. Creation of a restrictive atrial communication in heart failure with preserved and mid-range ejection fraction: effective palliation of left atrial hypertension and pulmonary congestion.

    Science.gov (United States)

    Bauer, Anna; Khalil, Markus; Lüdemann, Monika; Bauer, Jürgen; Esmaeili, Anoosh; De-Rosa, Roberta; Voelkel, Norbert F; Akintuerk, Hakan; Schranz, Dietmar

    2018-04-16

    Left atrial decompression is considered in patients with symptomatic heart failure with preserved ejection fraction (HFpEF). We aimed to evaluate the feasibility and efficacy of transcatheter generation of a restrictive atrial septum communication to manage HFpEF from infancy to adulthood with cardiomyopathy and congenital heart defect. From June 2009 to December 2016, 24 patients (50% with an age less than 16 years) with HFpEF were palliated; NYHA-/Ross class IV (n = 10); median systemic ventricular ejection fraction 64 (range 35-78) %. Cardiomyopathy was classified as a restrictive (n = 4) or hypertrophic (n = 2). (75% related to congenital heart defects) Three patients had a systemic right ventricle; in the majority of patients, HFpEF was associated to complex congenital heart defects (n = 18). Mean pulmonary arterial pressures (PAP systolic/diastolic) were 56/28 (± 24/13), left atrial pressures (LAP, v-, a-wave, mean) 26/25/20 (± 7/10/6). Trans-septal puncture was used in 22 patients; foramen ovale dilatation in 2 patients. Median balloon size was 12 (range 6-18) mm; procedure time including diagnostic measures 125 (83-221) min. No procedural death or complications were observed. Mean LA-pressures decreased significantly to 19/19/15 ± 6/8/5 mmHg (p = 0.05); median brain natriuretic peptide (BNP) decreased from 392 (range 93-4401) pg/ml median BNP to 314 (range 61-1544) pg/ml (p = 0.05). Three patients died; one patient received orthotopic heart and one patient a heart-lung transplantation. No patient required so far an assist device. Clinical improvement occurred in all patients, in some after additional surgical or interventional approach. Transcatheter LA decompression is an age-independent, effective palliation treating patients with HFpEF.

  13. Detection of atrial fibrillation and flutter by a dual-chamber implantable cardioverter-defibrillator. For the Worldwide Jewel AF Investigators.

    Science.gov (United States)

    Swerdlow, C D; Schsls, W; Dijkman, B; Jung, W; Sheth, N V; Olson, W H; Gunderson, B D

    2000-02-29

    To distinguish prolonged episodes of atrial fibrillation (AF) that require cardioversion from self-terminating episodes that do not, an atrial implantable cardioverter-defibrillator (ICD) must be able to detect AF continuously for extended periods. The ICD should discriminate between atrial tachycardia/flutter (AT), which may be terminated by antitachycardia pacing, and AF, which requires cardioversion. We studied 80 patients with AT/AF and ventricular arrhythmias who were treated with a new atrial/dual-chamber ICD. During a follow-up period lasting 6+/-2 months, we validated spontaneous, device-defined AT/AF episodes by stored electrograms in all patients. In 58 patients, we performed 80 Holter recordings with telemetered atrial electrograms, both to validate the continuous detection of AT/AF and to determine the sensitivity of the detection of AT/AF. Detection was appropriate in 98% of 132 AF episodes and 88% of 190 AT episodes (98% of 128 AT episodes with an atrial cycle length 1 hour, for a total of 2697 hours of continuous detection of AT/AF. During Holter monitoring, the sensitivity of the detection of AT/AF (116 hours) was 100%; the specificity of the detection of non-AT/AF rhythms (1290 hours) was 99.99%. Of 166 appropriate episodes detected as AT, 45% were terminated by antitachycardia pacing. A new ICD detects AT/AF accurately and continuously. Therapy may be programmed for long-duration AT/AF, with a low risk of underdetection. Discrimination of AT from AF permits successful pacing therapy for a significant fraction of AT.

  14. Role of atrial fibrillation and atrioventricular conduction (including Wolff-Parkinson-White Syndrome) in sudden death

    NARCIS (Netherlands)

    Meijler, F.L.; Tweel, I. van der; Herbschleb, J.N.; Hauer, R.N.W.; Robles de Medina, E.O.

    A short refractory period of the accessory pathway is considered a major threat for sudden death in patients with Wolff-Parkinson-White syndrome and atrial fibrillation. RR interval and QRS signal analysis together with signal analysis of a bipolar high right atrial electrogram were obtained in six

  15. Type of Atrial Fibrillation and Outcomes in Patients With Heart Failure and Reduced Ejection Fraction

    DEFF Research Database (Denmark)

    Mogensen, Ulrik M.; Jhund, Pardeep S.; Abraham, William T.

    2017-01-01

    Background Atrial fibrillation (AF) is common in heart failure (HF), but the outcome by type of AF is largely unknown. Objectives This study investigated outcomes related to type of AF (paroxysmal, persistent or permanent, or new onset) in 2 recent large trials in patients with HF with reduced...... risks in patients with persistent or permanent AF were not elevated. Neither type of AF was associated with higher mortality. New onset AF was associated with the greatest risk of adverse outcomes: primary endpoint (HR: 2.21; 95% CI: 1.80 to 2.71), HF hospitalization (HR: 2.11; 95% CI: 1.58 to 2.......81), stroke (HR: 2.20; 95% CI: 1.25 to 3.88), and all-cause mortality (HR: 2.26; 95% CI: 1.86 to 2.74), all p values permanent AF (71...

  16. Transcatheter treatment of heart failure with preserved or mildly reduced ejection fraction using a novel interatrial implant to lower left atrial pressure

    DEFF Research Database (Denmark)

    Søndergaard, Lars; Reddy, Vivek; Kaye, David

    2014-01-01

    BACKGROUND: Heart failure with preserved or mildly reduced ejection fraction (HFpEF) is common and, to date, therapeutic options are limited. Increased left atrial pressure is a key contributor to the symptoms associated with HFpEF, particularly during physical activity. We report the 30-day...... outcome of patients treated with a novel device intended to lower left atrial pressure by creating an 8 mm permanent shunt in the atrial septum. METHODS AND RESULTS: Eleven patients were enrolled in the pilot trial. Key inclusion criteria were: EF >45%; baseline PCWP ≥15 mmHg (rest), or ≥ 25 mm...... patients, one class in five patients, and worsened by one class in one patient. No patient developed pulmonary hypertension. Two serious adverse events occurred; heart failure re-hospitalization, and implant malposition successfully treated with a new device. CONCLUSION: Contemporary management of HFp...

  17. Angiotensin converting enzyme 2 activity and human atrial fibrillation: increased plasma angiotensin converting enzyme 2 activity is associated with atrial fibrillation and more advanced left atrial structural remodelling.

    Science.gov (United States)

    Walters, Tomos E; Kalman, Jonathan M; Patel, Sheila K; Mearns, Megan; Velkoska, Elena; Burrell, Louise M

    2017-08-01

    Angiotensin converting enzyme 2 (ACE2) is an integral membrane protein whose main action is to degrade angiotensin II. Plasma ACE2 activity is increased in various cardiovascular diseases. We aimed to determine the relationship between plasma ACE2 activity and human atrial fibrillation (AF), and in particular its relationship to left atrial (LA) structural remodelling. One hundred and three participants from a tertiary arrhythmia centre, including 58 with paroxysmal AF (PAF), 20 with persistent AF (PersAF), and 25 controls, underwent clinical evaluation, echocardiographic analysis, and measurement of plasma ACE2 activity. A subgroup of 20 participants underwent invasive LA electroanatomic mapping. Plasma ACE2 activity levels were increased in AF [control 13.3 (9.5-22.3) pmol/min/mL; PAF 16.9 (9.7-27.3) pmol/min/mL; PersAF 22.8 (13.7-33.4) pmol/min/mL, P = 0.006]. Elevated plasma ACE2 was associated with older age, male gender, hypertension and vascular disease, elevated left ventricular (LV) mass, impaired LV diastolic function and advanced atrial disease (P < 0.05 for all). Independent predictors of elevated plasma ACE2 activity were AF (P = 0.04) and vascular disease (P < 0.01). There was a significant relationship between elevated ACE2 activity and low mean LA bipolar voltage (adjusted R2 = 0.22, P = 0.03), a high proportion of complex fractionated electrograms (R2 = 0.32, P = 0.009) and a long LA activation time (R2 = 0.20, P = 0.04). Plasma ACE2 activity is elevated in human AF. Both AF and vascular disease predict elevated plasma ACE2 activity, and elevated plasma ACE2 is significantly associated with more advanced LA structural remodelling. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

  18. Ventricular rhythm in atrial fibrillation under anaesthetic infusion with propofol

    International Nuclear Information System (INIS)

    Cervigón, R; Moreno, J; Pérez-Villacastín, J; Reilly, R B; Castells, F

    2009-01-01

    Changes in patients' autonomic tone and specific pharmacologic interventions may modify the ventricular response (actual heart rate) during atrial fibrillation (AF). Hypnotic agents such as propofol may modify autonomic balance as they promote a sedative state. It has been shown that propofol slightly slows atrial fibrillatory activity, but the net global effect on the ventricular response remains unknown. We aimed to evaluate in patients in AF the effect of a propofol bolus on the ventricular rate and regularity at ECG. We analysed the possible relation with local atrial fibrillatory activities, as ratios between atrial and ventricular rates (AVRs), analysing atrial activity from intracardiac electrograms at the free wall of the right and left atria and at the interatrial septum. We compared data at the baseline and after complete hypnosis. Propofol was associated with a more homogeneous ventricular response and lower AVR values at the interatrial septum

  19. Cryoablation of Anteroseptal Accessory Pathways with a His Bundle Electrogram on the Ablation Catheter

    Directory of Open Access Journals (Sweden)

    Leonardo Liberman, MD

    2014-11-01

    Conclusions: In a small number of pediatric patients with AS AP with a His bundle electrogram seen on the ablation catheter, the use of cryotherapy was safe and effective for elimination of AP conduction without impairment of AV nodal conduction.

  20. Insights into new-onset atrial fibrillation following open heart surgery and implications for type II atrial flutter.

    Science.gov (United States)

    Sadrpour, Shervin A; Srinivasan, Deepa; Bhimani, Ashish A; Lee, Seungyup; Ryu, Kyungmoo; Cakulev, Ivan; Khrestian, Celeen M; Markowitz, Alan H; Waldo, Albert L; Sahadevan, Jayakumar

    2015-12-01

    Postoperative atrial fibrillation (POAF), new-onset AF after open heart surgery (OHS), is thought to be related to pericarditis. Based on AF studies in the canine sterile pericarditis model, we hypothesized that POAF in patients after OHS may be associated with a rapid, regular rhythm in the left atrium (LA), suggestive of an LA driver maintaining AF. The aim of this study was to test the hypothesis that in patients with POAF, atrial electrograms (AEGs) recorded from at least one of the two carefully selected LA sites would manifest a rapid, regular rhythm with AEGs of short cycle length (CL) and constant morphology, but a selected right atrial (RA) site would manifest AEGs with irregular CLs and variable morphology. In 44 patients undergoing OHS, AEGs recorded from the epicardial surface of the RA, the LA portion of Bachmann's bundle, and the posterior LA during sustained AF were analysed for regularity of CL and morphology. Sustained AF occurred in 15 of 44 patients. Atrial electrograms were recorded in 11 of 15 patients; 8 of 11 had rapid, regular activation with constant morphology recorded from at least one LA site; no regular AEG sites were present in 3 of 11 patients. Atrial electrograms recorded during sustained POAF frequently demonstrated rapid, regular activation in at least one LA site, consistent with a driver maintaining AF. Published by Oxford University Press on behalf of the European Society of Cardiology 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  1. Investigation of atrial vulnerability by analysis of the sinus node EG from atrial fibrillation models using a phase synchronization method.

    Science.gov (United States)

    Chen, Ying; Wu, Zhong; Yang, Cuiwei; Shao, Jun; Wong, Kelvin Kian Loong; Abbott, Derek

    2012-09-01

    Atrial fibrillation (AF) can result in life-threatening arrhythmia, and a clinically convenient means for detecting vulnerability remains elusive. We investigated atrial vulnerability by analyzing the sinus electrogram (EG) from AF animal models using a phase synchronization method. Using acetylcholine (ACh)-induced acute canine AF models (n= 4), a total of 128 electrical leads were attached to the surface of the anterior and posterior atria, and the pulmonary veins to form an electrocardiological mapping system. ACh was injected at varying concentrations with ladder-type adjustments. Sinus EGs and induced AF EGs that pertain to specific ACh concentrations were recorded.We hypothesize that the atrial vulnerability may be correlated with the Shannon entropy (SE) of the phase difference matrix that is extracted from the sinus EG. Our research suggests that the combination of SE with the synchronization method enables the sinus node EG to be analyzed and used to estimate atrial vulnerability.

  2. β-Blockers on Discharge From Acute Atrial Fibrillation Are Associated With Decreased Mortality and Lower Cerebrovascular Accidents in Patients With Heart Failure and Reduced Ejection Fraction.

    Science.gov (United States)

    Abi Khalil, Charbel; Zubaid, Mohammad; Asaad, Nidal; Rashed, Wafa A; Hamad, Adel Khalifa; Singh, Rajvir; Al Suwaidi, Jassim

    2018-04-01

    The benefits of β-blockers in patients with heart failure (HF) with reduced ejection fraction (HFrEF) and atrial fibrillation (AF) are controversial. The Gulf Survey of Atrial Fibrillation Events was a prospective, multinational, observational registry of consecutive patients with AF recruited from the emergency department (ED). We studied the incidence of 6- and 12-month mortality, hospitalization for HF or AF, and stroke/transient ischemic attacks (TIAs) in patients with HFrEF, in relation to β-blockers on discharge from the ED or the subsequent hospital stay. Of the 344 patients with HFrEF and AF in the GULF-SAFE, 177 patients (53%) were discharged on β-blockers. Mortality was lower in those patients compared with the non-β-blockers group at 6 and 12 months (odds ratios [ORs] 0.31, 95% CI [0.16-0.61]; OR 0.30, 95% CI [0.16-0.55]; P = .001 for both, respectively), so was the risk of stroke/TIAs. However, hospitalizations for AF increased in the β-blockers group. Even after adjustment for several risk variables in 2 different models, the beneficial effect of β-blockers on mortality persisted, at the cost of more hospitalization for AF.

  3. Effect of exercise on circulating atrial natriuretic peptide and left ventricular ejection fraction in healthy persons and patients with coronary artery disease

    International Nuclear Information System (INIS)

    Nakamura, Tetsuya; Ichikawa, Shuichi; Sakamaki, Tetsuo; Suzuki, Tadashi; Iizuka, Toshio; Yagi, Atsuko; Kurashina, Toshiaki; Kumakura, Hisao; Murata, Kazuhiko

    1988-01-01

    Radionuclide angiographic measurements of left ventricular ejection fraction were performed at rest and during exercise in 10 normal persons and 11 patients with coronary artery disease. Exercise was continued on a supine bicycle exercise table up to a symptom-limited maximum. Plasma levels of atrial natriuretic peptide (ANP) were also determined at rest and during exercise. Ejection fraction in the normal volunteers was 59±3% (mean±SEM) at rest and increased significantly (p<0.01) to 69±3% during exercise. Ejection fraction in the patients was 47±5% at rest and did not change significantly during exercise (51±7%). Plasma ANP in the normals rose significantly (p<0.01) from 62±16 pg/ml at rest to 454±94 pg/ml during exercise. Plasma ANP in the patients also rose significantly (p<0.01) from 231±102 pg/ml to 794±170 pg/ml. The response of plasma ANP to exercise was enhanced significantly (p<0.05) in the patients as compared with the normals in relation to ejection fraction by analysis of covariance. In both the normals and the patients, plasma ANP was inversely and significantly correlated with ejection fraction during exercise (r=0.46, p<0.05, n=21), however, not at rest. Because it has been reported that plasma ANP is correlated positively with pulmonary artery wedge pressure, the estimation of plasma ANP during an exercise stress test might be used for the evaluation of cardiac reserve in coronary artery disease. (author)

  4. Assessment of the dynamics of atrial signals and local atrial period series during atrial fibrillation: effects of isoproterenol administration

    Directory of Open Access Journals (Sweden)

    Mantica Massimo

    2004-10-01

    Full Text Available Abstract Background The autonomic nervous system (ANS plays an important role in the genesis and maintenance of atrial fibrillation (AF, but quantification of its electrophysiologic effects is extremely complex and difficult. Aim of the study was to evaluate the capability of linear and non-linear indexes to capture the fine changing dynamics of atrial signals and local atrial period (LAP series during adrenergic activation induced by isoproterenol (a sympathomimetic drug infusion. Methods Nine patients with paroxysmal or persistent AF (aged 60 ± 6 underwent electrophysiological study in which isoproterenol was administered to patients. Atrial electrograms were acquired during i sinus rhythm (SR; ii sinus rhythm during isoproterenol (SRISO administration; iii atrial fibrillation (AF and iv atrial fibrillation during isoproterenol (AFISO administration. The level of organization between two electrograms was assessed by the synchronization index (S, whereas the degree of recurrence of a pattern in a signal was defined by the regularity index (R. In addition, the level of predictability (LP and regularity of LAP series were computed. Results LAP series analysis shows a reduction of both LP and R index during isoproterenol infusion in SR and AF (RSR = 0.75 ± 0.07 RSRISO = 0.69 ± 0.10, p AF = 0.31 ± 0.08 RAFISO = 0.26 ± 0.09, p SR = 99.99 ± 0.001 LPSRISO = 99.97 ± 0.03, p AF = 69.46 ± 21.55 LPAFISO = 55 ± 24.75; p SR = 0.49 ± 0.08 RSRISO = 0.46 ± 0.09 p AF = 0.29 ± 0.09 RAFISO = 0.28 ± 0.08 n.s.. Conclusions The proposed parameters succeeded in discriminating the subtle changes due to isoproterenol infusion during both the rhythms especially when considering LAP series analysis. The reduced value of analyzed parameters after isoproterenol administration could reflect an important pro-arrhythmic influence of adrenergic activation on favoring maintenance of AF.

  5. Left ventricular ejection fraction and left atrium diameter related to new-onset atrial fibrillation following acute myocardial infarction: a systematic review and meta-analysis.

    Science.gov (United States)

    Zeng, Rui-Xiang; Chen, Mao-Sheng; Lian, Bao-Tao; Liao, Peng-Da; Zhang, Min-Zhou

    2017-10-06

    New-onset atrial fibrillation (NOAF) occurs frequently in patients with acute myocardial infarction (AMI), and is associated with increased subsequent cardiovascular mortality. However, only a few studies directly evaluated the relationship of left ventricular ejection fraction (LVEF) or left atrium diameter (LAD) and NOAF following AMI. MEDLINE ® , EMBASE ® and the Cochrane Library were carried out to find studies until January 2017. Pooled mean difference (MD) and 95% confidence interval (CI) were calculated to evaluate the value of LVEF and LAD in the prediction of NOAF after AMI. We performed sensitivity analyses to explore the potential sources of heterogeneity. Statistical analyses were carried out using the Revman 5.3. We included 10 qualifying studies comprising a total of 708 patients with NOAF and 6785 controls. Overall, decreased LVEF and increased LAD levels had a significant positive association with NOAF in patients with AMI. The MD in the LVEF levels between the patients with and those without NOAF was -4.91 units (95% Cl: -5.70 to -4.12), test for overall effect z-score = 12.18 ( p < 0.00001, I 2 = 35%). Moreover, in a subgroup analysis, the MD for LAD and NOAF was 2.55 units (95% Cl: 1.91 to 3.19), test for overall effect z-score = 7.80 ( p < 0.00001, I 2 = 57%). Our meta-analysis demonstrated that both decreased LVEF and increased LAD levels were associated with greater risk of NOAF following AMI.

  6. Manual Intracardiac Electrogram Method Is Accurate Alternative to Echocardiography for Atrioventricular and Interventricular Optimization in Cardiac Resynchronization Therapy.

    Science.gov (United States)

    Pezo Nikolić, Borka; Lovrić, Daniel; Ljubas Maček, Jana; Rešković Lukšić, Vlatka; Matasić, Richard; Šeparović Hanževački, Jadranka

    2017-12-01

    Some manufacturers do not provide automated intracardiac electrogram method (IEGM) systems for atrioventricular (AV) and interventricular (VV) delay optimization in cardiac resynchronization therapy (CRT). We aimed to evaluate the accuracy of manual IEGM method in 48 patients previously implanted with Medtronic Syncra CRT. All patients underwent standard device interrogation followed by CRT optimization by IEGM method and by echocardiography one month after implantation. The patient mean age was 60.7±11.8 years and there were 33 (68.8%) males. After CRT implantation, the left ventricular ejection fraction increased from 28.0±7.9% to 39.1±11.0% (p<0.001). Optimal aortic flow Velocity Time Integral (aVTI) was obtained when VV was set to 20-50 ms left ventricular pre-activation. There was a strong correlation between VV values determined by echocardiography and IEGM (R=0.823, p<0.001). We found no significant difference in AV, VV and aVTI values between echocardiography and IEGM method. However, IEGM was significantly less time-consuming than echocardiography [20 (10-28) vs. 40 (35-60) minutes, p<0.001]. Manual IEGM method may be good alternative to echocardiography and automated IEGM method. It also emphasizes the need for implementation of automated IEGM systems in as many CRT devices as possible.

  7. Spectral analysis of epicardial 60-lead electrograms in dogs with 4-week-old myocardial infarction.

    Science.gov (United States)

    Hosoya, Y; Ikeda, K; Komatsu, T; Yamaki, M; Kubota, I

    2001-01-01

    There were few studies on the spectral analysis of multiple-lead epicardial electrograms in chronic myocardial infarction. Spectral analysis of multi-lead epicardial electrograms was performed in 6 sham-operated dogs (N group) and 8 dogs with 4-week-old myocardial infarction (MI group). Four weeks after the ligation of left anterior descending coronary artery, fast Fourier transform was performed on 60-lead epicardial electrograms, and then inverse transform was performed on 5 frequency ranges from 0 to 250 Hz. From the QRS onset to QRS offset, the time integration of unsigned value of reconstructed waveform was calculated and displayed as AQRS maps. On 0-25 Hz AQRS map, there was no significant difference between the 2 groups. In the frequency ranges of 25-250 Hz, MI group had significantly smaller AQRS values than N group solely in the infarct zone. It was shown that high frequency potentials (25-250 Hz) within QRS complex were reduced in the infarct zone.

  8. Spatial characterization of electrogram morphology from transmural recordings in the intact normal heart.

    Directory of Open Access Journals (Sweden)

    Jim Pouliopoulos

    Full Text Available PURPOSE: Unipolar (UE and bipolar electrograms (BE are utilized to identify arrhythmogenic substrate. We quantified the effect of increasing distance from the source of propagation on local electrogram amplitude; and determined if transmural electrophysiological gradients exist with respect to propagation and stimulation depth. METHODS: Mapping was performed on 5 sheep. Deployment of >50 quadripolar transmural needles in the LV were located in Cartesian space using Ensite. Contact electrograms from all needles were recorded during multisite bipolar pacing from epicardial then endocardial electrodes. Analysis was performed to determine stimulus distance to local activation time, peak negative amplitude (V-P, and peak-peak amplitude (VP-P for (1 unfiltered UE, and (2 unfiltered and 30 Hz high-pass filtered BEs. Each sheep was analysed using repeated ANOVA. RESULTS: Increasing distance from the pacing sites led to significant (p0.01 during endocardial stimulation, and 2.3±2.4 ms (UE and 1.8±3.7 ms (BE during epicardal stimulation (all pVP-P. Conduction propagates preferentially via the epicardium during stimulation and is believed to contribute to a transmural amplitude gradient.

  9. Spiral wave classification using normalized compression distance: Towards atrial tissue spatiotemporal electrophysiological behavior characterization.

    Science.gov (United States)

    Alagoz, Celal; Guez, Allon; Cohen, Andrew; Bullinga, John R

    2015-08-01

    Analysis of electrical activation patterns such as re-entries during atrial fibrillation (Afib) is crucial in understanding arrhythmic mechanisms and assessment of diagnostic measures. Spiral waves are a phenomena that provide intuitive basis for re-entries occurring in cardiac tissue. Distinct spiral wave behaviors such as stable spiral waves, meandering spiral waves, and spiral wave break-up may have distinct electrogram manifestations on a mapping catheter. Hence, it is desirable to have an automated classification of spiral wave behavior based on catheter recordings for a qualitative characterization of spatiotemporal electrophysiological activity on atrial tissue. In this study, we propose a method for classification of spatiotemporal characteristics of simulated atrial activation patterns in terms of distinct spiral wave behaviors during Afib using two different techniques: normalized compressed distance (NCD) and normalized FFT (NFFTD). We use a phenomenological model for cardiac electrical propagation to produce various simulated spiral wave behaviors on a 2D grid and labeled them as stable, meandering, or breakup. By mimicking commonly used catheter types, a star shaped and a circular shaped both of which do the local readings from atrial wall, monopolar and bipolar intracardiac electrograms are simulated. Virtual catheters are positioned at different locations on the grid. The classification performance for different catheter locations, types and for monopolar or bipolar readings were also compared. We observed that the performance for each case differed slightly. However, we found that NCD performance is superior to NFFTD. Through the simulation study, we showed the theoretical validation of the proposed method. Our findings suggest that a qualitative wavefront activation pattern can be assessed during Afib without the need for highly invasive mapping techniques such as multisite simultaneous electrogram recordings.

  10. Atrial Fibrillation

    DEFF Research Database (Denmark)

    Staerk, Laila; Sherer, Jason A; Ko, Darae

    2017-01-01

    The past 3 decades have been characterized by an exponential growth in knowledge and advances in the clinical treatment of atrial fibrillation (AF). It is now known that AF genesis requires a vulnerable atrial substrate and that the formation and composition of this substrate may vary depending...... on comorbid conditions, genetics, sex, and other factors. Population-based studies have identified numerous factors that modify the atrial substrate and increase AF susceptibility. To date, genetic studies have reported 17 independent signals for AF at 14 genomic regions. Studies have established...

  11. Atrial Fibrillation: Diagnosis

    Science.gov (United States)

    ... of this page please turn JavaScript on. Feature: Atrial Fibrillation Atrial Fibrillation: Diagnosis Past Issues / Winter 2015 Table of Contents ... of your body's cells and organs. Read More "Atrial Fibrillation" Articles Atrial Fibrillation / Who Is at Risk for ...

  12. Magnetic electroanatomical mapping for ablation of focal atrial tachycardias.

    Science.gov (United States)

    Marchlinski, F; Callans, D; Gottlieb, C; Rodriguez, E; Coyne, R; Kleinman, D

    1998-08-01

    Uniform success for ablation of focal atrial tachycardias has been difficult to achieve using standard catheter mapping and ablation techniques. In addition, our understanding of the complex relationship between atrial anatomy, electrophysiology, and surface ECG P wave morphology remains primitive. The magnetic electroanatomical mapping and display system (CARTO) offers an on-line display of electrical activation and/or signal amplitude related to the anatomical location of the recorded sites in the mapped chamber. A window of electrical interest is established based on signals timed from an electrical reference that usually represents a fixed electrogram recording from the coronary sinus or the atrial appendage. This window of electrical interest is established to include atrial activation prior to the onset of the P wave activity associated with the site of origin of a focal atrial tachycardia. Anatomical and electrical landmarks are defined with limited fluoroscopic imaging support and more detailed global chamber and more focal atrial mapping can be performed with minimal fluoroscopic guidance. A three-dimensional color map representing atrial activation or voltage amplitude at the magnetically defined anatomical sites is displayed with on-line data acquisition. This display can be manipulated to facilitate viewing from any angle. Altering the zoom control, triangle fill threshold, clipping plane, or color range can all enhance the display of a more focal area of interest. We documented the feasibility of using this single mapping catheter technique for localizing and ablating focal atrial tachycardias. In a consecutive series of 8 patients with 9 focal atrial tachycardias, the use of the single catheter CARTO mapping system was associated with ablation success in all but one patient who had a left atrial tachycardia localized to the medial aspect of the orifice of the left atrial appendage. Only low power energy delivery was used in this patient because of the

  13. The effect of activation rate on left atrial bipolar voltage in patients with paroxysmal atrial fibrillation.

    Science.gov (United States)

    Williams, Steven E; Linton, Nick; O'Neill, Louisa; Harrison, James; Whitaker, John; Mukherjee, Rahul; Rinaldi, Christopher A; Gill, Jaswinder; Niederer, Steven; Wright, Matthew; O'Neill, Mark

    2017-09-01

    Bipolar voltage is used during electroanatomic mapping to define abnormal myocardium, but the effect of activation rate on bipolar voltage is not known. We hypothesized that bipolar voltage may change in response to activation rate. By examining corresponding unipolar signals we sought to determine the mechanisms of such changes. LA extrastimulus mapping was performed during CS pacing in 10 patients undergoing first time paroxysmal atrial fibrillation ablation. Bipolar and unipolar electrograms were recorded using a PentaRay catheter (4-4-4 spacing) and indifferent IVC electrode, respectively. An S1S2 pacing protocol was delivered with extrastimulus coupling interval reducing from 350 to 200 milliseconds. At each recording site (119 ± 37 per LA), bipolar peak-to-peak voltage, unipolar peak to peak voltage and activation delay between unipole pairs was measured. Four patterns of bipolar voltage/extrastimulus coupling interval curves were seen: voltage attenuation with plateau voltage >1 mV (48 ± 15%) or voltage unaffected by coupling interval with plateau voltage >1 mV (17 ± 10%) or voltage attenuation were associated with significantly greater unipolar voltage attenuation at low (25 ± 28 mV/s vs. 9 ± 11 mV/s) and high (23 ± 29 mV/s vs. 6 ± 12 mV/s) plateau voltage sites (P voltage attenuation (P = 0.026). Bipolar electrogram voltage is dependent on activation rate at a significant proportion of sites. Changes in unipolar voltage and timing underlie these effects. These observations have important implications for use of voltage mapping to delineate abnormal atrial substrate. © 2017 The Authors. Journal of Cardiovascular Electrophysiology published by Wiley Periodicals, Inc.

  14. ATRIAL FLUTTER*

    African Journals Online (AJOL)

    1971-01-02

    Jan 2, 1971 ... Athero- sclerotic cardiovascular disease was present in 23 patients, of whom 3 had ... primum defect, atrial flutter was precipitated by cardiac catheterization. ..... Heart J., 70, 505. UNDERSTANDING REACTIVE DEPRESSION*

  15. Atrial fibrillation

    African Journals Online (AJOL)

    ABEOLUGBENGAS

    Mean blood pressures were 126.03± ... optimal. Keywords: Atrial fibrillation, thrombosis, CHADS2 Score, stroke risk, hypertensive heart disease, ... general population and the average age group ... Appendix 1) to stratify the stroke risk and we.

  16. Ganglionated plexi stimulation induces pulmonary vein triggers and promotes atrial arrhythmogenecity: In silico modeling study.

    Directory of Open Access Journals (Sweden)

    Minki Hwang

    Full Text Available The role of the autonomic nervous system (ANS on atrial fibrillation (AF is difficult to demonstrate in the intact human left atrium (LA due to technical limitations of the current electrophysiological mapping technique. We examined the effects of the ANS on the initiation and maintenance of AF by employing a realistic in silico human left atrium (LA model integrated with a model of ganglionated plexi (GPs.We incorporated the morphology of the GP and parasympathetic nerves in a three-dimensional (3D realistic LA model. For the model of ionic currents, we used a human atrial model. GPs were stimulated by increasing the IK[ACh], and sympathetic nerve stimulation was conducted through a homogeneous increase in the ICa-L. ANS-induced wave-dynamics changes were evaluated in a model that integrated a patient's LA geometry, and we repeated simulation studies using LA geometries from 10 different patients.The two-dimensional model of pulmonary vein (PV cells exhibited late phase 3 early afterdepolarization-like activity under 0.05μM acetylcholine (ACh stimulation. In the 3D simulation model, PV tachycardia was induced, which degenerated to AF via GP (0.05μM ACh and sympathetic (7.0×ICa-L stimulations. Under sustained AF, local reentries were observed at the LA-PV junction. We also observed that GP stimulation reduced the complex fractionated atrial electrogram (CFAE-cycle length (CL, p<0.01 and the life span of phase singularities (p<0.01. GP stimulation also increased the overlap area of the GP and CFAE areas (CFAE-CL≤120ms, p<0.01. When 3 patterns of virtual ablations were applied to the 3D AF models, circumferential PV isolation including the GP was the most effective in terminating AF.Cardiac ANS stimulations demonstrated triggered activity, automaticity, and local reentries at the LA-PV junction, as well as co-localized GP and CFAE areas in the 3D in silico GP model of the LA.

  17. Assessment of ventricular excitation propagation velocity using intramyocardial electrograms and electron beam tomography images

    International Nuclear Information System (INIS)

    Kraft, A.; Schreier, G.; Hutten, H.; Kastner, P.; Rienmueller, R.; Grasser, B; Iberer, F.; Tscheliessnigg, K.H.

    1999-01-01

    The combination of intramyocardial electrogram (IEGM) recordings and 3D-reconstruction of the heart allows to relate electrophysiological with geometrical parameters of the heart. In 12 Heart transplants the distance of two epimyocardially implanted pacemaker leads d x and the propagation time f x have been correlated. Linear regression analysis revealed significant (p < 0,002) and strong (r = 0,82) correlation. The ventricular excitation propagation velocity (VEPV) within the examined patient group was found to be 0,53 m/s with an offset of 14.25 mm, which is caused by the extent of the electrodes and the region of early capture immediately after stimulation. (author)

  18. Origin and pharmacological response of atrial tachyarrhythmias induced by activation of mediastinal nerves in canines.

    Science.gov (United States)

    Armour, J Andrew; Richer, Louis-Philippe; Pagé, Pierre; Vinet, Alain; Kus, Teresa; Vermeulen, Michel; Nadeau, Réginald; Cardinal, René

    2005-03-31

    We sought to determine the sites of origin of atrial tachyarrhythmias induced by activating mediastinal nerves, as well as the response of such arrhythmias to autonomic modulation. Under general anaesthesia, atrioventricular block was induced after thoracotomy in 19 canines. Brief trains of 5 electrical stimuli were delivered to right-sided mediastinal nerves during the atrial refractory period. Unipolar electrograms were recorded from 191 right and left atrial epicardial sites under several conditions, i.e. (i) with intact nervous systems and following (ii) acute decentralization of the intrathoracic nervous system or administration of (iii) atropine, (iv) timolol, (v) hexamethonium. Concomitant right atrial endocardial mapping was performed in 7 of these dogs. Mediastinal nerve stimulation consistently initiated bradycardia followed by atrial tachyarrhythmias. In the initial tachyarrhythmia beats, early epicardial breakthroughs were identified in the right atrial free wall (28/50 episodes) or Bachmann bundle region (22/50), which corresponded to endocardial sites of origin associated with the right atrial subsidiary pacemaker complex, i.e. the crista terminalis and dorsal locations including the right atrial aspect of the interatrial septum. Neuronally induced responses were eliminated by atropine, modified by timolol and unaffected by acute neuronal decentralization. After hexamethonium, responses to extra-pericardial but not intra-pericardial nerve stimulation were eliminated. It is concluded that concomitant activation of cholinergic and adrenergic efferent intrinsic cardiac neurons induced by right-sided efferent neuronal stimulation initiates atrial tachyarrhythmias that originate from foci anatomically related to the right atrial pacemaker complex and tissues underlying major atrial ganglionated plexuses.

  19. A diagnostic algorithm to optimize data collection and interpretation of Ripple Maps in atrial tachycardias.

    Science.gov (United States)

    Koa-Wing, Michael; Nakagawa, Hiroshi; Luther, Vishal; Jamil-Copley, Shahnaz; Linton, Nick; Sandler, Belinda; Qureshi, Norman; Peters, Nicholas S; Davies, D Wyn; Francis, Darrel P; Jackman, Warren; Kanagaratnam, Prapa

    2015-11-15

    Ripple Mapping (RM) is designed to overcome the limitations of existing isochronal 3D mapping systems by representing the intracardiac electrogram as a dynamic bar on a surface bipolar voltage map that changes in height according to the electrogram voltage-time relationship, relative to a fiduciary point. We tested the hypothesis that standard approaches to atrial tachycardia CARTO™ activation maps were inadequate for RM creation and interpretation. From the results, we aimed to develop an algorithm to optimize RMs for future prospective testing on a clinical RM platform. CARTO-XP™ activation maps from atrial tachycardia ablations were reviewed by two blinded assessors on an off-line RM workstation. Ripple Maps were graded according to a diagnostic confidence scale (Grade I - high confidence with clear pattern of activation through to Grade IV - non-diagnostic). The RM-based diagnoses were corroborated against the clinical diagnoses. 43 RMs from 14 patients were classified as Grade I (5 [11.5%]); Grade II (17 [39.5%]); Grade III (9 [21%]) and Grade IV (12 [28%]). Causes of low gradings/errors included the following: insufficient chamber point density; window-of-interestRipple Maps in atrial tachycardias. This algorithm requires prospective testing on a real-time clinical platform. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  20. 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...

  1. [Atrial fibrillation].

    Science.gov (United States)

    Spinar, J; Vítovec, J

    2003-09-01

    Atrial fibrilation is the most frequent arrhythmia, the occurrence increasing with age and associated diseases. The incidence at the age below 60 years is markedly lower than one per cent, whereas in persons above 80 years of age it exceeds six per cent. The occurrence in patients with heart failure is from 10% (NYHA II) up to 50% (NYHA IV). Atrial fibrillation is classified into that observed for the first time and permanent, respectively, while transient forms include paroxyzmal and persistent atrial fibrillation. The diagnosis is based on ECG recording, while echocardiography is most significant. The therapy includes two basic questions--anticoagulant or anti-aggregation treatment and the control of rhythm or frequency. The anticoagulant therapy should be introduced in all patients, where contraindications are not present, being necessary before every cardioversion, provided atrial fibrillation lasts more than two days. In patients without any heart disease and with a physiological echocardiogram it is possible to administer only anti-aggregation treatment. Cardioversion (the control of rhythm) is recommended to all symptomatic patients, in other cases and especially in older persons the control of frequency is safer and of more advantage. Electrical cardioversion is more effective that a pharmacological treatment, the sinus rhythm is preferably controlled by dofetilid, ibutilid, propafenon and amiodaron. For the control of heart rate beta-blockers, diltiazem, verapamil and digitalis are recommended.

  2. Long-term biatrial recordings in post-operative atrial fibrillation.

    Science.gov (United States)

    Masè, M; Graffigna, A; Sinelli, S; Pallaoro, G; Nollo, G; Ravelli, F

    2010-01-01

    Although atrial fibrillation (AF) is a common complication of cardiac surgery, its pathophysiology remains unclear. The study of post-operative AF demands for the recording of cardiac electrical activity in correspondence of AF onset and progression. Long-term recordings in post-surgery patients could provide this information, but, to date, have been limited to surface signals, which precludes a characterization of the arrhythmic triggers and substrate. In this study we demonstrate the feasibility of a continuous long-term recording of atrial electrical activities from the right and left atria in post-surgery patients. Local atrial epicardial electrograms are acquired by positioning temporary pacing wires in the right and left atria at the end of the intervention, while three day recordings are obtained by a digital holter recorder, adapted to epicardial signal features. The capability of the system to map local atrial activity and the possibility to obtain quantitative information on atrial rate and synchronization from the processed epicardial signals are proven in representative examples. The quantitative description of local atrial properties opens new perspective in the investigation of post-surgery AF.

  3. Atrial Fibrillation: Treatment

    Science.gov (United States)

    ... of this page please turn JavaScript on. Feature: Atrial Fibrillation Atrial Fibrillation: Treatment Past Issues / Winter 2015 Table of Contents Treatment for atrial fibrillation depends on how often you have symptoms, how ...

  4. Spatial Relation Between Left Atrial Anatomical Contact Areas and Circular Activation in Persistent Atrial Fibrillation.

    Science.gov (United States)

    Nakahara, Shiro; Yamaguchi, Takanori; Hori, Yuichi; Anjo, Naofumi; Hayashi, Akiko; Kobayashi, Sayuki; Komatsu, Takaaki; Sakai, Yoshihiko; Fukui, Akira; Tsuchiya, Takeshi; Taguchi, Isao

    2016-05-01

    Atrial low-voltage zones (LVZs) may be related to maintenance of atrial fibrillation (AF). The influence of left atrial (LA) contact areas (CoAs) on reentrant or rotor-like sources maintaining AF has not been investigated. Forty patients with persistent AF (PsAF) were analyzed. Three representative CoA regions in the LA (ascending aorta: anterior wall; descending aorta: left inferior pulmonary vein; and vertebrae: posterior wall) were visualized by enhanced CT. Using circular catheters, the LVZs (80% of the mean AF cycle length. A pivot was defined as the core of the localized circular activation. Anterior (39/40 patients, 98%), left pulmonary vein antrum (27/40, 68%), and posterior (19/40, 48%) CoAs were identified, and 80% (68/85) of those sites were overlapped by or close (<3 mm) to LVZs. Thirty-six (90%) patients demonstrated circular activation (3.1±1.7 sites/patients) along with significantly higher organized dominant frequencies (6.3 ± 0.5 Hz, regularity-index: 0.26 [0.23-0.41]) within the LA, and the average electrogram amplitude of those pivots was 0.30 mV (0.18-0.52). Of those sites, 55% (66/120) were located at or close to CoA regions. Catheter ablation including of LVZs neighboring CoAs terminated AF in 9 (23%) patients. External anatomical structures contacting the LA may be related to unique conduction properties in diseased myocardium necessary for PsAF maintenance. © 2016 Wiley Periodicals, Inc.

  5. Diastolic Function in Normal Sinus Rhythm vs. Chronic Atrial Fibrillation: Comparison by Fractionation of E-wave Deceleration Time into Stiffness and Relaxation Components.

    Science.gov (United States)

    Mossahebi, Sina; Kovács, Sándor J

    2014-01-01

    Although the electrophysiologic derangement responsible for atrial fibrillation (AF) has been elucidated, how AF remodels the ventricular chamber and affects diastolic function (DF) has not been fully characterized. The previously validated Parametrized Diastolic Filling (PDF) formalism models suction-initiated filling kinematically and generates error-minimized fits to E-wave contours using unique load (x o ), relaxation (c), and stiffness (k) parameters. It predicts that E-wave deceleration time (DT) is a function of both stiffness and relaxation. Ascribing DT s to stiffness and DTr to relaxation such that DT=DT s +DT r is legitimate because of causality and their predicted and observed high correlation (r=0.82 and r=0.94) with simultaneous (diastatic) chamber stiffness (dP/dV) and isovolumic relaxation (tau), respectively. We analyzed simultaneous echocardiography-cardiac catheterization data and compared 16 age matched, chronic AF subjects to 16, normal sinus rhythm (NSR) subjects (650 beats). All subjects had diastatic intervals. Conventional DF parameters (DT, AT, E peak , E dur , E-VTI, E/E') and E-wave derived PDF parameters (c, k, DT s , DT r ) were compared. Total DT and DT s , DT r in AF were shorter than in NSR (pwave DT in AF is due to stiffness compared to NSR. By trending individual subjects, this method can elucidate and characterize the beneficial or adverse long-term effects on chamber remodeling due to alternative therapies in terms of chamber stiffness and relaxation.

  6. Efficient computation of electrograms and ECGs in human whole heart simulations using a reaction-eikonal model.

    Science.gov (United States)

    Neic, Aurel; Campos, Fernando O; Prassl, Anton J; Niederer, Steven A; Bishop, Martin J; Vigmond, Edward J; Plank, Gernot

    2017-10-01

    Anatomically accurate and biophysically detailed bidomain models of the human heart have proven a powerful tool for gaining quantitative insight into the links between electrical sources in the myocardium and the concomitant current flow in the surrounding medium as they represent their relationship mechanistically based on first principles. Such models are increasingly considered as a clinical research tool with the perspective of being used, ultimately, as a complementary diagnostic modality. An important prerequisite in many clinical modeling applications is the ability of models to faithfully replicate potential maps and electrograms recorded from a given patient. However, while the personalization of electrophysiology models based on the gold standard bidomain formulation is in principle feasible, the associated computational expenses are significant, rendering their use incompatible with clinical time frames. In this study we report on the development of a novel computationally efficient reaction-eikonal (R-E) model for modeling extracellular potential maps and electrograms. Using a biventricular human electrophysiology model, which incorporates a topologically realistic His-Purkinje system (HPS), we demonstrate by comparing against a high-resolution reaction-diffusion (R-D) bidomain model that the R-E model predicts extracellular potential fields, electrograms as well as ECGs at the body surface with high fidelity and offers vast computational savings greater than three orders of magnitude. Due to their efficiency R-E models are ideally suitable for forward simulations in clinical modeling studies which attempt to personalize electrophysiological model features.

  7. A new LMS algorithm for analysis of atrial fibrillation signals.

    Science.gov (United States)

    Ciaccio, Edward J; Biviano, Angelo B; Whang, William; Garan, Hasan

    2012-03-26

    A biomedical signal can be defined by its extrinsic features (x-axis and y-axis shift and scale) and intrinsic features (shape after normalization of extrinsic features). In this study, an LMS algorithm utilizing the method of differential steepest descent is developed, and is tested by normalization of extrinsic features in complex fractionated atrial electrograms (CFAE). Equations for normalization of x-axis and y-axis shift and scale are first derived. The algorithm is implemented for real-time analysis of CFAE acquired during atrial fibrillation (AF). Data was acquired at a 977 Hz sampling rate from 10 paroxysmal and 10 persistent AF patients undergoing clinical electrophysiologic study and catheter ablation therapy. Over 24 trials, normalization characteristics using the new algorithm with four weights were compared to the Widrow-Hoff LMS algorithm with four tapped delays. The time for convergence, and the mean squared error (MSE) after convergence, were compared. The new LMS algorithm was also applied to lead aVF of the electrocardiogram in one patient with longstanding persistent AF, to enhance the F wave and to monitor extrinsic changes in signal shape. The average waveform over a 25 s interval was used as a prototypical reference signal for matching with the aVF lead. Based on the derivation equations, the y-shift and y-scale adjustments of the new LMS algorithm were shown to be equivalent to the scalar form of the Widrow-Hoff LMS algorithm. For x-shift and x-scale adjustments, rather than implementing a long tapped delay as in Widrow-Hoff LMS, the new method uses only two weights. After convergence, the MSE for matching paroxysmal CFAE averaged 0.46 ± 0.49 μV(2)/sample for the new LMS algorithm versus 0.72 ± 0.35 μV(2)/sample for Widrow-Hoff LMS. The MSE for matching persistent CFAE averaged 0.55 ± 0.95 μV(2)/sample for the new LMS algorithm versus 0.62 ± 0.55 μV(2)/sample for Widrow-Hoff LMS. There were no significant differences in estimation

  8. A new LMS algorithm for analysis of atrial fibrillation signals

    Directory of Open Access Journals (Sweden)

    Ciaccio Edward J

    2012-03-01

    Full Text Available Abstract Background A biomedical signal can be defined by its extrinsic features (x-axis and y-axis shift and scale and intrinsic features (shape after normalization of extrinsic features. In this study, an LMS algorithm utilizing the method of differential steepest descent is developed, and is tested by normalization of extrinsic features in complex fractionated atrial electrograms (CFAE. Method Equations for normalization of x-axis and y-axis shift and scale are first derived. The algorithm is implemented for real-time analysis of CFAE acquired during atrial fibrillation (AF. Data was acquired at a 977 Hz sampling rate from 10 paroxysmal and 10 persistent AF patients undergoing clinical electrophysiologic study and catheter ablation therapy. Over 24 trials, normalization characteristics using the new algorithm with four weights were compared to the Widrow-Hoff LMS algorithm with four tapped delays. The time for convergence, and the mean squared error (MSE after convergence, were compared. The new LMS algorithm was also applied to lead aVF of the electrocardiogram in one patient with longstanding persistent AF, to enhance the F wave and to monitor extrinsic changes in signal shape. The average waveform over a 25 s interval was used as a prototypical reference signal for matching with the aVF lead. Results Based on the derivation equations, the y-shift and y-scale adjustments of the new LMS algorithm were shown to be equivalent to the scalar form of the Widrow-Hoff LMS algorithm. For x-shift and x-scale adjustments, rather than implementing a long tapped delay as in Widrow-Hoff LMS, the new method uses only two weights. After convergence, the MSE for matching paroxysmal CFAE averaged 0.46 ± 0.49μV2/sample for the new LMS algorithm versus 0.72 ± 0.35μV2/sample for Widrow-Hoff LMS. The MSE for matching persistent CFAE averaged 0.55 ± 0.95μV2/sample for the new LMS algorithm versus 0.62 ± 0.55μV2/sample for Widrow

  9. Digoxin for atrial fibrillation and atrial flutter

    DEFF Research Database (Denmark)

    Sethi, Naqash J; Nielsen, Emil E; Safi, Sanam

    2018-01-01

    BACKGROUND: During recent years, systematic reviews of observational studies have compared digoxin to no digoxin in patients with atrial fibrillation or atrial flutter, and the results of these reviews suggested that digoxin seems to increase the risk of all-cause mortality regardless...... of concomitant heart failure. Our objective was to assess the benefits and harms of digoxin for atrial fibrillation and atrial flutter based on randomized clinical trials. METHODS: We searched CENTRAL, MEDLINE, Embase, LILACS, SCI-Expanded, BIOSIS for eligible trials comparing digoxin versus placebo......, no intervention, or other medical interventions in patients with atrial fibrillation or atrial flutter in October 2016. Our primary outcomes were all-cause mortality, serious adverse events, and quality of life. Our secondary outcomes were heart failure, stroke, heart rate control, and conversion to sinus rhythm...

  10. Electrophysiologic studies in atrial fibrillation. Slow conduction of premature impulses: a possible manifestation of the background for reentry.

    Science.gov (United States)

    Cosio, F G; Palacios, J; Vidal, J M; Cocina, E G; Gómez-Sánchez, M A; Tamargo, L

    1983-01-01

    Extrastimulus-induced intraatrial conduction delays were measured in 12 patients with documented episodes of atrial fibrillation (AF) by recording atrial electrograms at the high right atrium, His bundle region, and coronary sinus. Seventeen patients with and without heart disease, but without atrial arrhythmias served as the control group. During baseline-paced atrial rhythms, a conduction delay zone could be delineated, near the atrial effective refractory period, during which all extrastimuli produced conduction delays. When compared at the same paced cycle lengths (500 to 650 ms), the patients with AF had shorter atrial effective refractory periods (mean +/- standard deviation 206 +/- 24.1 versus 233 +/- 28.2 in control patients, p less than 0.02), wider conduction delay zones (79 +/- 21.7 ms versus 52 +/- 21 in control patients, p less than 0.01), and longer conduction delays both to the His bundle region (64 +/- 18.3 ms versus 35 +/- 21.7 in control patients, p less than 0.005) and the coronary sinus (76 +/- 18.9 ms versus 35 +/- 16.1 in control patients, p less than 0.001). Repetitive atrial responses were recorded in 6 patients with AF and in 9 control subjects. Sinus nodal function abnormalities were detected in 6 of the patients with fibrillation. Patients with AF had a higher tendency than control subjects to develop slow intraatrial conduction, as well as shorter effective refractory periods. Since both features would favor reentry, they may be the electrophysiologic manifestations of the abnormalities making these patients prone to atrial reentrant arrhythmias. Repetitive atrial responses were of no predictive value. Sinus nodal dysfunction was frequently found, but was not essential for the occurrence of AF.

  11. Atrial fibrillation or flutter

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000184.htm Atrial fibrillation or flutter To use the sharing features on this page, please enable JavaScript. Atrial fibrillation or flutter is a common type of abnormal ...

  12. Atrial fibrillation - discharge

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000237.htm Atrial fibrillation - discharge To use the sharing features on this ... have been in the hospital because you have atrial fibrillation . This condition occurs when your heart beats faster ...

  13. Atrial Fibrillation - Multiple Languages

    Science.gov (United States)

    ... Are Here: Home → Multiple Languages → All Health Topics → Atrial Fibrillation URL of this page: https://medlineplus.gov/languages/ ... V W XYZ List of All Topics All Atrial Fibrillation - Multiple Languages To use the sharing features on ...

  14. Real-Time Rotational Activity Detection in Atrial Fibrillation

    Science.gov (United States)

    Ríos-Muñoz, Gonzalo R.; Arenal, Ángel; Artés-Rodríguez, Antonio

    2018-01-01

    Rotational activations, or spiral waves, are one of the proposed mechanisms for atrial fibrillation (AF) maintenance. We present a system for assessing the presence of rotational activity from intracardiac electrograms (EGMs). Our system is able to operate in real-time with multi-electrode catheters of different topologies in contact with the atrial wall, and it is based on new local activation time (LAT) estimation and rotational activity detection methods. The EGM LAT estimation method is based on the identification of the highest sustained negative slope of unipolar signals. The method is implemented as a linear filter whose output is interpolated on a regular grid to match any catheter topology. Its operation is illustrated on selected signals and compared to the classical Hilbert-Transform-based phase analysis. After the estimation of the LAT on the regular grid, the detection of rotational activity in the atrium is done by a novel method based on the optical flow of the wavefront dynamics, and a rotation pattern match. The methods have been validated using in silico and real AF signals. PMID:29593566

  15. Atrial Fibrillation: Complications

    Science.gov (United States)

    ... of this page please turn JavaScript on. Feature: Atrial Fibrillation Atrial Fibrillation: Complications Past Issues / Winter 2015 Table of Contents ... has two major complications—stroke and heart failure. Atrial Fibrillation and Stroke Click to enlarge image This illustration ...

  16. Novel Percutaneous Epicardial Autonomic Modulation in the Canine for Atrial Fibrillation: Results of an Efficacy and Safety Study

    Science.gov (United States)

    Madhavan, Malini; Venkatachalam, K. L.; Swale, Matthew J.; DeSimone, Christopher V.; Gard, Joseph J.; Johnson, Susan B.; Suddendorf, Scott H.; Mikell, Susan B.; Ladewig, Dorothy J.; Nosbush, Toni Grabinger; Danielsen, Andrew J.; Knudson, Mark; Asirvatham, Samuel J.

    2016-01-01

    Background Endocardial ablation of atrial ganglionated plexi (GP) has been described for treatment of atrial fibrillation (AF). Our objective in this study was to develop percutaneous epicardial GP ablation in a canine model using novel energy sources and catheters. Methods Phase 1: The efficacy of several modalities to ablate the GP was tested in an open chest canine model (n=10). Phase 2: Percutaneous epicardial ablation of GP was done in 6 dogs using the most efficacious modality identified in phase 1 using 2 novel catheters. Results Phase 1: DC in varying doses [blocking (7 -12μA), electroporation (300-500μA), ablation (3000- 7500μA)], radiofrequency ablation (25–50 W), ultrasound (1.5MHz), and alcohol (2-5ml) injection were successful at 0/8, 4/12, 5/7, 3/8, 1/5 and 5/7 GP sites. DC (500–5000μA) along with alcohol irrigation was tested in phase 2. Phase 2: Percutaneous epicardial ablation of the right atrium, oblique sinus, vein of Marshall, and transverse sinus GP was successful in 5/6 dogs. One dog died of ventricular fibrillation (VF) during DC ablation at 5000 μA. Programmed stimulation induced AF in 6 dogs pre-ablation and no atrial arrhythmia in 3, flutter in 1 and AF in 1 post-ablation. Heart rate, blood pressure, effective atrial refractory period and local atrial electrogram amplitude did not change significantly post-ablation. Microscopic examination showed elimination of GP, and minimal injury to atrial myocardium. Conclusion Percutaneous epicardial ablation of GP using direct current and novel catheters is safe and feasible and may be used as an adjunct to pulmonary vein isolation in the treatment of atrial fibrillation in order to minimize additional atrial myocardial ablation. PMID:26854009

  17. 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

  18. Force Trends and Pulsatility for Catheter Contact Identification in Intracardiac Electrograms during Arrhythmia Ablation.

    Science.gov (United States)

    Rivas-Lalaleo, David; Muñoz-Romero, Sergio; Huerta, Mónica; Erazo-Rodas, Mayra; Sánchez-Muñoz, Juan José; Rojo-Álvarez, José Luis; García-Alberola, Arcadi

    2018-05-02

    The intracardiac electrical activation maps are commonly used as a guide in the ablation of cardiac arrhythmias. The use of catheters with force sensors has been proposed in order to know if the electrode is in contact with the tissue during the registration of intracardiac electrograms (EGM). Although threshold criteria on force signals are often used to determine the catheter contact, this may be a limited criterion due to the complexity of the heart dynamics and cardiac vorticity. The present paper is devoted to determining the criteria and force signal profiles that guarantee the contact of the electrode with the tissue. In this study, we analyzed 1391 force signals and their associated EGM recorded during 2 and 8 s, respectively, in 17 patients (82 ± 60 points per patient). We aimed to establish a contact pattern by first visually examining and classifying the signals, according to their likely-contact joint profile and following the suggestions from experts in the doubtful cases. First, we used Principal Component Analysis to scrutinize the force signal dynamics by analyzing the main eigen-directions, first globally and then grouped according to the certainty of their tissue-catheter contact. Second, we used two different linear classifiers (Fisher discriminant and support vector machines) to identify the most relevant components of the previous signal models. We obtained three main types of eigenvectors, namely, pulsatile relevant, non-pulsatile relevant, and irrelevant components. The classifiers reached a moderate to sufficient discrimination capacity (areas under the curve between 0.84 and 0.95 depending on the contact certainty and on the classifier), which allowed us to analyze the relevant properties in the force signals. We conclude that the catheter-tissue contact profiles in force recordings are complex and do not depend only on the signal intensity being above a threshold at a single time instant, but also on time pulsatility and trends. These

  19. Pulmonary vein isolation in the treatment of atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Kumar S

    2016-05-01

    Full Text Available Saurabh Kumar, Gregory F Michaud Cardiac Arrhythmia Service, Cardiovascular Division, Brigham and Women's Hospital, Boston, MA, USA Abstract: Atrial fibrillation (AF is the commonest arrhythmia in humans and is associated with marked reduction in quality of life and an elevated thromboembolic risk. Paroxysmal, persistent, and permanent forms of AF have been recognized. Whilst antiarrhythmic drugs are considered as first-line therapy, the role of catheter ablation is increasing due to its superior efficacy in terms of quality of life and reduction in AF burden. The central paradigm for catheter ablation of AF is that triggers for AF are located near and within the pulmonary veins (PVs, and electrical isolation of the PVs from the left atrium forms the cornerstone of most catheter ablation strategies. Whilst paroxysmal form is generally trigger dependent, persistent and permanent forms are associated with variable interaction between triggers and "substrate" comprised of atrial and PV electrical and structural remodeling. Nevertheless, isolation of the PVs still forms a critical component of catheter ablation strategies, regardless of AF type. Procedural efficacy, however, is limited by PV conduction recovery. This is likely due to deficiencies in ablation tools or limitations of intraprocedural assessment of lesion efficacy. Careful attention to surrogates of tissue heating, such as impedance decrease and electrogram morphology changes, along with advances in catheter technology like contact force catheters may improve rates of durable PV isolation and single-procedural success. This review discusses the mechanism of paroxysmal AF with particular focus on the role of the PVs in AF initiation and PV isolation in the management of AF. Keywords: contact force, lesion transmurality, radiofrequency catheter ablation, paroxysmal atrial fibrillation, electrophysiology, AF

  20. Surgery for atrial fibrillation.

    Science.gov (United States)

    Viganò, M; Graffigna, A; Ressia, L; Minzioni, G; Pagani, F; Aiello, M; Gazzoli, F

    1996-01-01

    The mechanisms of atrial fibrillation arc multiple reentry circuits spinning around the atrial surface, and these baffle any attempt to direct surgical interruption. The purpose of this article is to report the surgical experience in the treatment of isolated and concomitant atrial fibrillation at the Cardiac Surgical Institute of the University of Pavia. In cases of atrial fibrillation secondary to mitral/valve disease, surgical isolation of the left atrium at the time of mitral valve surgery can prevent atrial fibrillation from involving the right atrium, which can exert its diastolic pump function on the right ventricle. Left atrial isolation was performed on 205 patients at the time of mitral valve surgery. Atrial partitioning ("maze operation") creates straight and blind atrial alleys so that non-recentry circuits can take place. Five patients underwent this procedure. In eight-cases of atrial fibrillation secondary to atrial septal defect, the adult patients with atrial septal defect and chronic or paroxysmal atrial fibrillation underwent surgical isolation of the right atrium associated which surgical correction of the defect, in order to let sinus rhythm govern the left atrium and the ventricles. "Lone" atrial fibrillation occurs in hearts with no detectable organic disease. Bi-atrial isolation with creation of an atrial septal internodal "corridor" was performed on 14 patients. In cases of atrial fibrillation secondary to mitral valve disease, left atrial isolation was performed on 205 patients at the time of mitral valve surgery with an overall sinus rhythm recovery of 44%. In the same period, sinus rhythm was recovered and persisted in only 19% of 252 patients who underwent mitral valve replacement along (P < 0.001). Sinus rhythm was less likely to recover in patients with right atriomegaly requiring tricuspid valve annuloplasty: 59% vs 84% (P < 0.001). Restoration of the right atrial function raised the cardiac index from 2.25 +/- 0.55 1/min per m2

  1. Organized Atrial Tachycardias after Atrial Fibrillation Ablation

    Science.gov (United States)

    Castrejón-Castrejón, Sergio; Ortega, Marta; Pérez-Silva, Armando; Doiny, David; Estrada, Alejandro; Filgueiras, David; López-Sendón, José L.; Merino, José L.

    2011-01-01

    The efficacy of catheter-based ablation techniques to treat atrial fibrillation is limited not only by recurrences of this arrhythmia but also, and not less importantly, by new-onset organized atrial tachycardias. The incidence of such tachycardias depends on the type and duration of the baseline atrial fibrillation and specially on the ablation technique which was used during the index procedure. It has been repeatedly reported that the more extensive the left atrial surface ablated, the higher the incidence of organized atrial tachycardias. The exact origin of the pathologic substrate of these trachycardias is not fully understood and may result from the interaction between preexistent regions with abnormal electrical properties and the new ones resultant from radiofrequency delivery. From a clinical point of view these atrial tachycardias tend to remit after a variable time but in some cases are responsible for significant symptoms. A precise knowledge of the most frequent types of these arrhythmias, of their mechanisms and components is necessary for a thorough electrophysiologic characterization if a new ablation procedure is required. PMID:21941669

  2. Right atrial isolation associated with atrial septal closure in patients with atrial septal defect and chronic atrial fibrillation.

    Science.gov (United States)

    Minzioni, G; Graffigna, A; Pagani, F; Vigano, M

    1993-12-01

    To restore sinus rhythm in the remaining heart chambers of six adult patients with atrial septal defect and chronic or paroxysmal atrial fibrillation, electrical, right atrial isolation associated with surgical correction of the defect was performed. All but one patient was free from atrial fibrillation without medication 2-25 months after operation. The isolated right atrial appendages showed intrinsic rhythmical activity in five patients and no electrical activity in one. Right atrial isolation is a safe and effective procedure that abolishes atrial fibrillation in patients with arrhythmia after surgical correction of atrial septal defect.

  3. Atrial Fibrillation and Hyperthyroidism

    Directory of Open Access Journals (Sweden)

    Jayaprasad N

    2005-10-01

    Full Text Available Atrial fibrillation occurs in 10 – 15% of patients with hyperthyroidism. Low serum thyrotropin concentration is an independent risk factor for atrial fibrillation. Thyroid hormone contributes to arrythmogenic activity by altering the electrophysiological characteristics of atrial myocytes by shortening the action potential duration, enhancing automaticity and triggered activity in the pulmonary vein cardio myocytes. Hyperthyroidism results in excess mortality from increased incidence of circulatory diseases and dysrhythmias. Incidence of cerebral embolism is more in hyperthyroid patients with atrial fibrillation, especially in the elderly and anti-coagulation is indicated in them. Treatment of hyperthyroidism results in conversion to sinus rhythm in up to two-third of patients. Beta-blockers reduce left ventricular hypertrophy and atrial and ventricular arrhythmias in patients with hyperthyroidism. Treatment of sub clinical hyperthyroidism is controversial. Optimizing dose of thyroxine treatment in those with replacement therapy and beta-blockers is useful in exogenous subclinical hyperthyroidism.

  4. Atrioventricular node functional remodeling induced by atrial fibrillation.

    Science.gov (United States)

    Zhang, Youhua; Mazgalev, Todor N

    2012-09-01

    The atrioventricular node (AVN) plays a vital role in determining the ventricular rate during atrial fibrillation (AF). AF results in profound electrophysiological and structural remodeling in the atria as well as the sinus node. However, it is unknown whether AVN undergoes remodeling during AF. To determine whether AVN undergoes functional remodeling during AF. AVN conduction properties were studied in vitro in 9 rabbits with AF and 10 normal controls. A previously validated index of AVN dual-pathway electrophysiology, His-electrogram alternans, was used to monitor fast-pathway or slow-pathway (SP) AVN conduction in these experiments. AVN conduction properties were further studied in vivo in 7 dogs with chronic AF and 8 controls. Compared with the control rabbits, the rabbits with AF had a longer AVN conduction time (83 ± 16 ms vs 68 ± 7 ms; P AVN effective refractory period (141 ± 27 ms vs 100 ± 9 ms; P AVN effective refractory period and a slower ventricular rate during AF compared with the controls. Pronounced AVN functional electrophysiological remodeling occurs after long-term AF, which could lead to a spontaneous slowing of the ventricular rate. Furthermore, the SP dominance during AF underscores the effectiveness of its modification by ablation for ventricular rate control during AF. Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  5. Atrial Fibrillation Ablation Guided by a Novel Nonfluoroscopic Navigation System.

    Science.gov (United States)

    Ballesteros, Gabriel; Ramos, Pablo; Neglia, Renzo; Menéndez, Diego; García-Bolao, Ignacio

    2017-09-01

    Rhythmia is a new nonfluoroscopic navigation system that is able to create high-density electroanatomic maps. The aim of this study was to describe the acute outcomes of atrial fibrillation (AF) ablation guided by this system, to analyze the volume provided by its electroanatomic map, and to describe its ability to locate pulmonary vein (PV) reconnection gaps in redo procedures. This observational study included 62 patients who underwent AF ablation with Rhythmia compared with a retrospective cohort who underwent AF ablation with a conventional nonfluoroscopic navigation system (Ensite Velocity). The number of surface electrograms per map was significantly higher in Rhythmia procedures (12 125 ± 2826 vs 133 ± 21 with Velocity; P < .001), with no significant differences in the total procedure time. The Orion catheter was placed for mapping in 99.5% of PV (95.61% in the control group with a conventional circular mapping catheter; P = .04). There were no significant differences in the percentage of PV isolation between the 2 groups. In redo procedures, an ablation gap could be identified on the activation map in 67% of the reconnected PV (40% in the control group; P = .042). The measured left atrial volume was lower than that calculated by computed tomography (109.3 v 15.2 and 129.9 ± 13.2 mL, respectively; P < .001). There were no significant differences in the number of complications. The Rhythmia system is effective for AF ablation procedures, with procedure times and safety profiles similar to conventional nonfluoroscopic navigation systems. In redo procedures, it appears to be more effective in identifying reconnected PV conduction gaps. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  6. Atrial conduction times and left atrial mechanical functions and their relation with diastolic function in prediabetic patients.

    Science.gov (United States)

    Gudul, Naile Eris; Karabag, Turgut; Sayin, Muhammet Rasit; Bayraktaroglu, Taner; Aydin, Mustafa

    2017-03-01

    The aim of this study was to investigate atrial conduction times and left atrial mechanical functions, the noninvasive predictors of atrial fibrillation, in prediabetic patients with impaired fasting glucose (IFG) and impaired glucose tolerance (IGT). Study included 59 patients (23 males, 36 females; mean age 52.5 ± 10.6 years) diagnosed with IFG or IGT by the American Diabetes Association criteria, and 43 healthy adults (22 males, 21 females; mean age 48.5 ± 12.1 years). Conventional and tissue Doppler echocardiography were performed. The electromechanical delay parameters were measured from the onset of the P wave on the surface electrocardiogram to the onset of the atrial systolic wave on tissue Doppler imaging from septum, lateral, and right ventricular annuli. The left atrial volumes were calculated by the disk method. Left atrial mechanical functions were calculated. The mitral E/A and E'/A' ratios measured from the lateral and septal annuli were significantly lower in the prediabetics compared to the controls. The interatrial and left atrial electromechanical delay were significantly longer in prediabetic group compared to the controls. Left atrial active emptying volume (LAAEV) and fraction (LAAEF) were significantly higher in the prediabetics than the controls. LAAEV and LAAEF were significantly correlated with E/A, lateral and septal E'/A'. In the prediabetic patients, the atrial conduction times and P wave dispersion on surface electrocardiographic were longer before the development of overt diabetes. In addition, the left atrial mechanical functions were impaired secondary to a deterioration in the diastolic functions in the prediabetic patients.

  7. Antiarrhythmic properties of atrial pacing.

    Science.gov (United States)

    Kliś, Magdalena; Sławuta, Agnieszka; Gajek, Jacek

    2017-01-01

    Bradycardia, atrial stretch and dilatation, autonomic nervous system disorders, and the presence of triggers such as atrial premature contractions, are factors which predispose a person to paroxysmal AF. Atrial pacing not only eliminates bradycardia but also prevents atrial premature contractions and dispersion of refractoriness, which are a substrate for atrial fibrillation. As the prolonged duration of atrial activation during pacing, especially from locations changing the physiological pattern of this activation (right atrium lateral wall, right atrium appendage), negatively influences both a mechanical and an electrical function of the atria, the atrial pacing site affects an atrial arrhythmogenesis. A conventional atrial lead location in the right atrium appendage causes non-physiological activation propagation, resulting in a prolongation of the activation time of both atria. This location is optimal according to a passive fixation of the atrial lead but the available contemporary active fixation leads could potentially be located in any area of the atrium. There is growing evidence of the benefit of pacing, imitating the physiological propagation of impulses within the atria. It seems that the Bachmann's bundle pacing is the best pacing site within the atria, not only positively influencing the atrial mechanical function but also best fulfilling the so-called atrial resynchronization function, in particular in patients with interatrial conduction delay. It can be effectively achieved using only one atrial electrode, and the slight shortening of atrioventricular conduction provides an additional benefit of this atrial pacing site.

  8. [Effect of benazepril on atrial cytoskeleton remodeling in the canine atrial fibrillation models].

    Science.gov (United States)

    Liu, Li; Qu, Xiu-Fen; Yu, Yang; Bai, Bing; Huang, Yong-Lin

    2009-10-20

    To investigate the effect of benazepril on atrial cytoskeleton remodeling in atrial fibrillation (AF) canines induced by chronic rapid atrial pacing (RAP). Twenty canines were randomly divided into 3 groups: (1) Sham-operated group without RAP; (2) AF group: AF established by RAP at 600 beats per minute for 6 weeks; (3) Benazepril group: benazepril was dosed from 1 week pre-pacing to 6 weeks post-pacing. The diameter of atrial cardiomyocyte was measured, collagen volume fraction (CVF) analyzed by Masson staining and the expression and distribution of desmin were assayed by immunohistochemistry. RT-PCR method was used to semi-quantify the mRNA expression of beta-tubulin and desmin. The diameter of atrial cardiomyocyte increased in AF group [LA:(27.9 +/- 3.8) microm; RA: (26.8 +/- 3.2) microm] and benazepril group[LA: (25.1 +/- 3.4) microm; RA: (25.2 +/- 3.5) microm] than sham-operated group [LA: (19.6 +/- 2.9) microm; RA: (18.7 +/- 2.6) microm] (P benazepril group than AF group [LA: (11.3 +/- 0.8)% vs (16.9 +/- 1.1)%, RA: (10.9 +/- 0.8)% vs (15.7 +/- 2.3)%, P benazepril group than AF group (P benazepril group than AF group (LA:0.8 +/- 0.4 vs 1.0 +/- 0.3, 0.7 +/- 0.3 vs 0.9 +/- 0.4; RA:0.7 +/- 0.3 vs 1.0 +/- 0.6, 0.7 +/- 0.3 vs 1.1 +/- 0.3, P Benazepril can favorably improve atrial cytoskeleton remodeling in the canine atrial fibrillation model.

  9. What Is Atrial Fibrillation?

    Science.gov (United States)

    ANSWERS by heart Cardiovascular Conditions What Is Atrial Fibrillation? Your heart has a natural pacemaker, called the “sinus node,” that makes electrical signals. These signals cause the heart to contract and pump ...

  10. Atrial therapies reduce atrial arrhythmia burden in defibrillator patients.

    Science.gov (United States)

    Friedman, P A; Dijkman, B; Warman, E N; Xia, H A; Mehra, R; Stanton, M S; Hammill, S C

    2001-08-28

    Approximately 25% of patients who receive an implantable cardioverter-defibrillator (ICD) to treat ventricular tachyarrhythmias have documented atrial tachyarrhythmias before implantation. This study assessed the ability of device-based prevention and termination therapies to reduce the burden of spontaneous atrial tachyarrhythmias. Patients with a standard indication for the implantation of an ICD and 2 episodes of atrial tachyarrhythmias in the preceding year received a dual-chamber ICD (Medtronic 7250 Jewel AF) that uses pacing and shock therapies for prevention and/or termination of atrial tachyarrhythmias. In a multicenter trial, patients were randomized to 3-month periods with atrial therapies "on" or "off" and subsequently crossed over. Analysis was performed on the 52 of 269 patients who had episodes of atrial tachyarrhythmia and had >/=30 days of follow-up with atrial therapies on and off. The atrial therapies resulted in a reduction of atrial tachyarrhythmia burden from a mean of 58.5 to 7.8 h/mo. A paired analysis (Wilcoxon signed-rank test) showed that the median difference in burden (1.1 h/mo) was highly significant (P=0.007). When the subgroup of 41 patients treated only with atrial pacing therapies was analyzed, the reduction in burden persisted (P=0.01). In this study, patients with a standard ICD indication and atrial tachyarrhythmias had a significant reduction in atrial tachyarrhythmia burden with use of atrial pacing and shock therapies.

  11. Waveform Integrity in Atrial Fibrillation: The Forgotten Issue of Cardiac Electrophysiology.

    Science.gov (United States)

    Martínez-Iniesta, Miguel; Ródenas, Juan; Alcaraz, Raúl; Rieta, José J

    2017-08-01

    Atrial fibrillation (AF) is the most common arrhythmia in clinical practice with an increasing prevalence of about 15% in the elderly. Despite other alternatives, catheter ablation is currently considered as the first-line therapy for the treatment of AF. This strategy relies on cardiac electrophysiology systems, which use intracardiac electrograms (EGM) as the basis to determine the cardiac structures contributing to sustain the arrhythmia. However, the noise-free acquisition of these recordings is impossible and they are often contaminated by different perturbations. Although suppression of nuisance signals without affecting the original EGM pattern is essential for any other later analysis, not much attention has been paid to this issue, being frequently considered as trivial. The present work introduces the first thorough study on the significant fallout that regular filtering, aimed at reducing acquisition noise, provokes on EGM pattern morphology. This approach has been compared with more refined denoising strategies. Performance has been assessed both in time and frequency by well established parameters for EGM characterization. The study comprised synthesized and real EGMs with unipolar and bipolar recordings. Results reported that regular filtering altered substantially atrial waveform morphology and was unable to remove moderate amounts of noise, thus turning time and spectral characterization of the EGM notably inaccurate. Methods based on Wavelet transform provided the highest ability to preserve EGM morphology with improvements between 20 and beyond 40%, to minimize dominant atrial frequency estimation error with up to 25% reduction, as well as to reduce huge levels of noise with up to 10 dB better reduction. Consequently, these algorithms are recommended as a replacement of regular filtering to avoid significant alterations in the EGMs. This could lead to more accurate and truthful analyses of atrial activity dynamics aimed at understanding and

  12. Effect of left ventricular diastolic dysfunction on left atrial appendage function and thrombotic potential in nonvalvular atrial fibrillation.

    Science.gov (United States)

    Demirçelik, Muhammed Bora; Çetin, Mustafa; Çiçekcioğlu, Hülya; Uçar, Özgül; Duran, Mustafa

    2014-05-01

    We aimed to investigate effects of left ventricular diastolic dysfunction on left atrial appendage functions, spontaneous echo contrast and thrombus formation in patients with nonvalvular atrial fibrillation. In 58 patients with chronic nonvalvular atrial fibrilation and preserved left ventricular systolic function, left atrial appendage functions, left atrial spontaneous echo contrast grading and left ventricular diastolic functions were evaluated using transthoracic and transoesophageal echocardiogram. Patients divided in two groups: Group D (n=30): Patients with diastolic dysfunction, Group N (n=28): Patients without diastolic dysfunction. Categorical variables in two groups were evaluated with Pearson's chi-square or Fisher's exact test. The significance of the lineer correlation between the degree of spontaneous echo contrast (SEC) and clinical measurements was evaluated with Spearman's correlation analysis. Peak pulmonary vein D velocity of the Group D was significantly higher than the Group N (p=0.006). However, left atrial appendage emptying velocity, left atrial appendage lateral wall velocity, peak pulmonary vein S, pulmonary vein S/D ratio were found to be significantly lower in Group D (p=0.028, patrial appendage emptying, filling, pulmonary vein S/D levels and lateral wall velocities respectively (r=-0.438, r=-0.328, r=-0.233, r=-0.447). Left atrial appendage emptying, filling, pulmonary vein S/D levels and lateral wall velocities were significantly lower in SEC 2-3-4 than SEC 1 (p=0.003, p=0.029, patrial fibrillation and preserved left ventricular ejection fraction, left atrial appendage functions are decreased in patients with left ventricular diastolic dysfunction. Left ventricular diastolic dysfunction may constitute a potential risk for formation of thrombus and stroke.

  13. Risk Factors for Atrial Fibrillation

    NARCIS (Netherlands)

    B.P. Krijthe (Bouwe)

    2013-01-01

    textabstractAtrial fibrillation is a common cardiac arrhythmia that is characterized by rapid disorganized atrial electrical activity resulting in absence of atrial contractions. It is diagnosed on the basis of typical findings on an electrocardiogram (ECG). The characteristic ECG findings are

  14. Left atrial appendage occlusion

    Directory of Open Access Journals (Sweden)

    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.

  15. Clinical Differences between Subtypes of Atrial Fibrillation and Flutter: Cross-Sectional Registry of 407 Patients

    Directory of Open Access Journals (Sweden)

    Eduardo Dytz Almeida

    2015-01-01

    Full Text Available Introduction: Atrial fibrillation and atrial flutter account for one third of hospitalizations due to arrhythmias, determining great social and economic impacts. In Brazil, data on hospital care of these patients is scarce. Objective: To investigate the arrhythmia subtype of atrial fibrillation and flutter patients in the emergency setting and compare the clinical profile, thromboembolic risk and anticoagulants use. Methods: Cross-sectional retrospective study, with data collection from medical records of every patient treated for atrial fibrillation and flutter in the emergency department of Instituto de Cardiologia do Rio Grande do Sul during the first trimester of 2012. Results: We included 407 patients (356 had atrial fibrillation and 51 had flutter. Patients with paroxysmal atrial fibrillation were in average 5 years younger than those with persistent atrial fibrillation. Compared to paroxysmal atrial fibrillation patients, those with persistent atrial fibrillation and flutter had larger atrial diameter (48.6 ± 7.2 vs. 47.2 ± 6.2 vs. 42.3 ± 6.4; p < 0.01 and lower left ventricular ejection fraction (66.8 ± 11 vs. 53.9 ± 17 vs. 57.4 ± 16; p < 0.01. The prevalence of stroke and heart failure was higher in persistent atrial fibrillation and flutter patients. Those with paroxysmal atrial fibrillation and flutter had higher prevalence of CHADS2 score of zero when compared to those with persistent atrial fibrillation (27.8% vs. 18% vs. 4.9%; p < 0.01. The prevalence of anticoagulation in patients with CHA2DS2-Vasc ≤ 2 was 40%. Conclusions: The population in our registry was similar in its comorbidities and demographic profile to those of North American and European registries. Despite the high thromboembolic risk, the use of anticoagulants was low, revealing difficulties for incorporating guideline recommendations. Public health strategies should be adopted in order to improve these rates.

  16. Recurrent atrial myxoma.

    Science.gov (United States)

    Macarie, C; Stoica, E; Chioncel, O; Carp, A; Gherghiceanu, D; Stiru, O; Zarma, L; Herlea, V

    2004-01-01

    We have chosen this case of sporadic atrial myxoma for our presentation because it had a particular evolution, with recurrence at 8 years after surgical excision (echocardiography was performed every year) and a particular diagnostic means - at echocardiographic follow-up, the patient being asymptomatic. This presentation, together with a review of literature included in the article, emphasizes the importance of a careful postoperative follow-up of the patients and the existence of some particular aspects of the evolution and symptomatology of recurrent atrial myxoma.

  17. Thyrotoxic atrial fibrillation.

    Science.gov (United States)

    Parmar, Malvinder S

    2005-01-04

    Atrial fibrillation is the most common cardiac complication of hyperthyroidism and occurs in 15% of patients with hyperthyroidism. It is associated with a higher risk of thromboembolism that often involves the central nervous system. Oral anticoagulation is important in the majority of these patients to prevent thromboembolic complications. These patients require adjustment in the dose of various rate-controlling agents because of increased clearance associated with hyperthyroidism and a decrease in warfarin dosage because of increased clearance of vitamin K-dependent clotting factors. The management of thyrotoxic atrial fibrillation is summarized in this clinical review.

  18. Incidence and predictors of asymptomatic atrial fibrillation in patients older than 70 years with complete atrioventricular block and dual chamber pacemaker implantation.

    LENUS (Irish Health Repository)

    Radeljic, Vjekoslav

    2012-01-31

    AIM: To evaluate predictors of asymptomatic atrial fibrillation in patients older than 70 years with complete atrioventricular (AV) block, normal left ventricular systolic function, and implanted dual chamber (DDD) pacemaker. METHODS: Hundred and eighty six patients with complete AV block were admitted over one year to the Sisters of Mercy University Hospital. The study recruited patients older than 70 years, with no history of atrial fibrillation, heart failure, or reduced left ventricular systolic function. All the patients were implanted with the same pacemaker. Out of 103 patients who were eligible for the study, 81 (78%) were evaluated. Among those 81 (78%) were evaluated. Eighty one (78%) patients were evaluated. Follow-up time ranged from 12 to 33 months (average +\\/-standard deviation 23 +\\/- 5 months). Primary end-point was asymptomatic atrial fibrillation occurrence recorded by the pacemaker. Atrial fibrillation occurrence was defined as atrial high rate episodes (AHRE) lasting >5 minutes. Binary logistic regression was used to identify the predictors of development of asymptomatic atrial fibrillation. Results. The 81 patients were stratified into two groups depending on the presence of AHRE lasting >5 minutes (group 1 had AHRE>5 minutes and group 2 AHRE<5 minutes). AHRE lasting >5 minutes were detected in 49 (60%) patients after 3 months and in 53 (65%) patients after 18 moths. After 3 months, only hypertension (odds ratio [OR], 17.63; P = 0.020) was identified as a predictor of asymptomatic atrial fibrillation. After 18 months, hypertension (OR, 14.0; P = 0.036), P wave duration >100 ms in 12 lead ECG (OR, 16.5; P = 0.001), and intracardial atrial electrogram signal amplitude >4 mV (OR, 4.27; P = 0.045) were identified as predictors of atrial fibrillation. CONCLUSION: In our study population, hypertension was the most robust and constant predictor of asymptomatic atrial fibrillation after 3 months, while P wave duration >100 ms in 12-lead ECG and

  19. [Catheter ablation of ectopic incessant atrial tachycardia using radiofrequency. Reversion of tachycardiomyopathy].

    Science.gov (United States)

    de Paola, A A; Mendonça, A; Balbão, C E; Tavora, M Z; da Silva, R M; Hara, V M; Guiguer Júnior, N; Vattimo, A C; Souza, I A; Portugal, O P

    1993-10-01

    A 8-year-old female patient with refractory incessant atrial tachycardia, very symptomatic and with left ventricular ejection fraction of 0.25. Electrophysiological study and endocardial mapping localized the site of the origin of atrial tachycardia in the superior right atrium. In this site 2 applications of radiofrequency current (25V, 20 and 50 seconds) resulted in termination of the atrial tachycardia. She was discharged off antiarrhythmic drugs and after 2 months ejection fraction was 0.52. She was completely asymptomatic 6 months after ablation procedure.

  20. 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

    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

  1. Pharmacological Treatment for Atrial Fibrillation

    Directory of Open Access Journals (Sweden)

    Kaoru Sugi, MD PhD

    2005-01-01

    Full Text Available Pharmacological treatment for atrial fibrillation has a variety of purposes, such as pharmacological defibrillation, maintenance of sinus rhythm, heart rate control to prevent congestive heart failure and prevention of both cerebral infarction and atrial remodeling. Sodium channel blockers are superior to potassium channel blockers for atrial defibrillation, while both sodium and potassium channel blockers are effective in the maintenance of sinus rhythm. In general, digitalis or Ca antagonists are used to control heart rate during atrial fibrillation to prevent congestive heart failure, while amiodarone or bepridil also reduce heart rates during atrial fibrillation. Anticoagulant therapy with warfarin is recommended to prevent cerebral infarction and angiotensin converting enzyme antagonists or angiotensin II receptor blockers are also used to prevent atrial remodeling. One should select appropriate drugs for treatment of atrial fibrillation according to the patient's condition.

  2. Increased amount of atrial fibrosis in patients with atrial fibrillation secondary to mitral valve disease

    NARCIS (Netherlands)

    Geuzebroek, Guillaume S. C.; van Amersfoorth, Shirley C. M.; Hoogendijk, Mark G.; Kelder, Johannes C.; van Hemel, Norbert M.; de Bakker, Jacques M. T.; Coronel, Ruben

    2012-01-01

    Objective: Atrial fibrosis is related to atrial fibrillation but may differ in patients with mitral valve disease or lone atrial fibrillation. Therefore, we studied atrial fibrosis in patients with atrial fibrillation + mitral valve disease or with lone atrial fibrillation and compared it with

  3. 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

  4. Screening for Atrial Fibrillation

    DEFF Research Database (Denmark)

    Freedman, Ben; Camm, John; Calkins, Hugh

    2017-01-01

    Approximately 10% of ischemic strokes are associated with atrial fibrillation (AF) first diagnosed at the time of stroke. Detecting asymptomatic AF would provide an opportunity to prevent these strokes by instituting appropriate anticoagulation. The AF-SCREEN international collaboration was formed...

  5. [Left atrial function and left atrial appendage flow velocity in hypertrophic cardiomyopathy: comparison of patients with and without paroxysmal atrial fibrillation].

    Science.gov (United States)

    Akasaka, K; Kawashima, E; Shiokoshi, T; Ishii, Y; Hasebe, N; Kikuchi, K

    1998-07-01

    The involvement of left atrial (LA) appendage flow velocity in reduced left atrial function was investigated in 24 patients with hypertrophic cardiomyopathy, who retained sinus rhythm at the examination. Patients were divided into 11 with a history of paroxysmal atrial fibrillation [PAf(+)] and 13 without such history [PAf(-)]. Transthoracic echocardiography was performed to evaluate LA fractional shortening (LA%FS) and mean velocity of circumferential LA fiber shortening (LAmVcf), as contractile functions of the left atrium at the phase of active atrial contraction. Transesophageal echocardiographic Doppler examination was performed in all patients to measure the LA appendage velocity. In all patients, significant positive correlations were observed between the LA appendage velocity and LA%FS (r = 0.50, p fibrillation were significantly lower than in those without (0.84 +/- 0.15 vs 1.28 +/- 0.37 circ/sec, 44 +/- 12 vs 65 +/- 20 cm/sec, both p fibrillation. These results indicate that there is a close relationship between LA appendage velocity and LA contractile function in patients with hypertrophic cardiomyopathy with paroxysmal atrial fibrilation, and these patients have potential risk of cerebral infarction.

  6. Genetics Home Reference: familial atrial fibrillation

    Science.gov (United States)

    ... Twitter Home Health Conditions Familial atrial fibrillation Familial atrial fibrillation Printable PDF Open All Close All Enable Javascript to view the expand/collapse boxes. Description Familial atrial fibrillation is an inherited abnormality of the heart's normal ...

  7. Impact of congestive heart failure and left ventricular systolic function on the prognostic significance of atrial fibrillation and atrial flutter following acute myocardial infarction

    DEFF Research Database (Denmark)

    Pedersen, Ole Dyg; Bagger, Henning; Køber, Lars

    2005-01-01

    fibrillation in acute myocardial infarction patients that might explain previous discrepancies. METHODS: The study population was 6676 patients consecutively admitted to hospital with acute myocardial infarction. Information on the presence of atrial fibrillation/flutter, left ventricular systolic function......BACKGROUND: Reports on the prognostic importance of atrial fibrillation following myocardial infarction have provided considerable variation in results. Thus, this study examined the impact of left ventricular systolic function and congestive heart failure on the prognostic importance of atrial...... and congestive heart failure were prospectively collected. Mortality was followed for 5 years. RESULTS: In patients with left ventricular ejection fraction

  8. [Echocardiographic diagnosis of atrial thrombosis].

    Science.gov (United States)

    Pinto Tortolero, R; Vargas Barrón, J; Rodas, M A; Díaz de la Vega, V; Horwitz, S

    1982-01-01

    Seventy patients with rheumatic mitral disease were studied by M-Mode and 2D echocardiography in order to detect left atrial thrombosis before surgery. Thrombosis were suspected by the observation of abnormal echoes in the left atrium. During surgery 17 (24%) patients had atrial thrombosis. It had been suspected by echocardiography in 12 (sensitivity 70%). In 53 patients thrombosis were not found during surgery; in 46 the echo had been also negative (specificity 86%). There was a false positive detection of thrombosis by echo in 7 patients (14%) and false negativity in 5 (30%). Patients with atrial thrombosis had atrial fibrilation in 91% of cases; and the most frequent valvular disease was mitral stenosis. There was not a direct relationship among existence of left atrial thrombosis and the anteroposterior diameter of the left atrium as measured by echo. We conclude that echocardiography has good specificity to rule out atrial thrombosis and moderate sensitivity to detect it in rheumatic mitral disease.

  9. 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

  10. Verapamil eliminates the hierarchical nature of activation frequencies from the pulmonary veins to the atria during paroxysmal atrial fibrillation.

    Science.gov (United States)

    Kushiyama, Yasunori; Osaka, Toshiyuki; Yokoyama, Eriko; Hasebe, Hideyuki; Kuroda, Yusuke; Kamiya, Kaichiro; Kodama, Itsuo

    2010-05-01

    There is evidence that verapamil promotes the persistence of paroxysmal atrial fibrillation (AF). Little is known about the underlying mechanisms. The purpose of this study was to determine the effect of verapamil on dominant frequencies (DFs) in the pulmonary veins (PVs) and atria during paroxysmal AF with reference to its potential arrhythmogenicity. Forty-three patients with paroxysmal AF were studied. Bipolar electrograms were recorded simultaneously during AF from the right atrial free wall (RAFW), coronary sinus (CS) and three PVs, or two PVs and the left atrial appendage (LAA). The DFs were obtained by fast Fourier transform analysis before and after infusion of verapamil (0.1 mg/kg, intravenously). At baseline, the maximum DF among the PVs (6.9 +/- 0.9 Hz) was significantly higher than the DF in the RAFW (6.2 +/- 0.7 Hz), CS (5.7 +/- 0.5 Hz), or LAA (5.9 +/- 0.7 Hz) (Patrial DF gradient (RAFW 0.7 +/- 0.9, CS 1.1 +/- 0.7, LAA 0.7 +/- 0.9 Hz). Verapamil increased the atrial DF to 6.9 +/- 0.8, 6.6 +/- 0.7, and 7.2 +/- 1.0 Hz in the RAFW, CS, and LAA, respectively (Patrial DF gradient was eliminated after verapamil (RAFW 0.2 +/- 0.8, CS 0.5 +/- 0.6, LAA -0.4 +/- 0.8 Hz; Patrial DF gradient during paroxysmal AF. Copyright 2010 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  11. Atrial fibrillation in the elderly

    Science.gov (United States)

    Franken, Roberto A.; Rosa, Ronaldo F.; Santos, Silvio CM

    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. PMID:22916053

  12. Atrial Fibrillation and Coronary Bypass Surgery – What Can Be Risk Factors for its' Appearance?

    Directory of Open Access Journals (Sweden)

    Slavenka Štraus

    2010-02-01

    Full Text Available The main goal of our study was to evalúate possible perioperative risk factors for occurrence of atrial fibrillation in the postoperative period in patients after CABG operations. The study included 140 patients after CABG, divided into two groups - Group I - 64 patients with new onset of POAF and Group II - 76 patients without postoperative atrial fibrillation occurrence. In both groups possible risk factors for atrial fibrillation onset (preoperative and postoperative were analyzed.Results showed that we can predict new onset of atrial fibrillation after CABG if the following preoperative factors are present - low ejection fraction (less than 40%, LAd > 40mm, higher body mass index (BMI over 30, presence of COPD and older age. Important perioperative factors for onset of atrial fibrillation in our study were longer extracorporeal circulation, increased dose/number of inotropic drugs, blood transfusion and elevated WBC count postoperatively.

  13. Right atrial lipoma

    Directory of Open Access Journals (Sweden)

    Pêgo-Fernandes Paulo M.

    2003-01-01

    Full Text Available Benign cardiac tumors are rare, and lipomas are among those less frequently found. We report the case of a 48-year-old male complaining of high blood pressure and epistaxis in the last 2 months, with a diagnosis of right atrial lipoma established on echocardiography, magnetic resonance imaging, and anatomicopathological examination. The tumor was successfully removed, and up to 42 months after surgical excision, no evidence of tumor relapse was observed.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Abnormal atrial activation in young patients with lone atrial fibrillation

    DEFF Research Database (Denmark)

    Holmqvist, Fredrik; Olesen, Morten S; Tveit, Arnljot

    2011-01-01

    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 hearts....

  16. Effect of atrial preference pacing on reducing long-term burden of atrial fibrillation:a clinical study

    International Nuclear Information System (INIS)

    Xu Jianfeng; Chen Yueguang; Su Yangang; Zhang Dadong

    2010-01-01

    Objective: To evaluate the clinical effect of atrial preference pacing (APP) on the prevention of paroxysmal atrial fibrillation. Methods: Based on the type of implanted pacemaker, 46 patients with sick sinus syndrome and paroxysmal atrial fibrillation were divided into two groups. Dual-chamber pacemaker equipped with APP function was implanted in patients of group APP (n=21), while conventional dual-chamber pacemaker was implanted in patients of control group (n=25). The patients were followed up for six months, the maximum P wave duration (Pmax), the P wave dispersion (Pd), the structure of heart chambers, the data of automatic mode switch (AMS) and the total burden of atrial fibrillation were estimated,and the results were statistically analyzed and compared between two groups. Results: The basic clinical characteristics of two groups were comparable. After six months pacing, the difference in Pmax between two groups was of no significance (115.0 ± 10.1 ms vs 122.0 ± 11.0 ms, P > 0.05), while the increase of Pd in control group was more obvious than that in group APP (32.7 ± 4.2 ms vs 20.1 ± 5.3 ms, P 0.05), and also no remarkable difference in the left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV) and left ventricular ejection fraction (LVEF) could be found (P > 0.05). Moreover, no significant difference existed between two groups (P > 0.05). After six months pacing,in group APP the frequencies of AMS decreased more sharply (145 ± 37 times vs 327 ± 13 times, P < 0.05), the duration of AMS shortened more apparently (73 ± 15 hours vs 139 ± 28 hours, P < 0.05) and the total burden of atrial fibrillation was alleviated more obviously (13 ± 5% vs 28 ± 6%, P < 0.05) when compared to those in control group. Conclusion: Atrial preference pacing can coordinate the anisotropy of double atrial depolarization, reduce the frequencies of long-term paroxysmal atrial fibrillation, shorten the duration of atrial fibrillation

  17. Effects of Prolonged Spaceflight on Atrial Size, Atrial Electrophysiology, and Risk of Atrial Fibrillation.

    Science.gov (United States)

    Khine, Htet W; Steding-Ehrenborg, Katarina; Hastings, Jeffrey L; Kowal, Jamie; Daniels, James D; Page, Richard L; Goldberger, Jeffery J; Ng, Jason; Adams-Huet, Beverley; Bungo, Michael W; Levine, Benjamin D

    2018-05-01

    The prevalence of atrial fibrillation (AF) in active astronauts is ≈5%, similar to the general population but at a younger age. Risk factors for AF include left atrial enlargement, increased number of premature atrial complexes, and certain parameters on signal-averaged electrocardiography, such as P-wave duration, root mean square voltage for the terminal 20 ms of the signal-averaged P wave, and P-wave amplitude. We aimed to evaluate changes in atrial structure, supraventricular beats, and atrial electrophysiology to determine whether spaceflight could increase the risk of AF. Thirteen astronauts underwent cardiac magnetic resonance imaging to assess atrial structure and function before and after 6 months in space and high-resolution Holter monitoring for multiple 48-hour time periods before flight, during flight, and on landing day. Left atrial volume transiently increased after 6 months in space (12±18 mL; P =0.03) without changing atrial function. Right atrial size remained unchanged. No changes in supraventricular beats were noted. One astronaut had a large increase in supraventricular ectopic beats but none developed AF. Filtered P-wave duration did not change over time, but root mean square voltage for the terminal 20 ms decreased on all fight days except landing day. No changes in P-wave amplitude were seen in leads II or V 1 except landing day for lead V 1 . Six months of spaceflight may be sufficient to cause transient changes in left atrial structure and atrial electrophysiology that increase the risk of AF. However, there was no definite evidence of increased supraventricular arrhythmias and no identified episodes of AF. © 2018 American Heart Association, Inc.

  18. Atrial fibrillation: Therapeutic potential of atrial K+ channel blockers.

    Science.gov (United States)

    Ravens, Ursula; Odening, Katja E

    2017-08-01

    Despite the epidemiological scale of atrial fibrillation, current treatment strategies are of limited efficacy and safety. Ideally, novel drugs should specifically correct the pathophysiological mechanisms responsible for atrial fibrillation with no other cardiac or extracardiac actions. Atrial-selective drugs are directed toward cellular targets with sufficiently different characteristics in atria and ventricles to modify only atrial function. Several potassium (K + ) channels with either predominant expression in atria or distinct electrophysiological properties in atria and ventricles can serve as atrial-selective drug targets. These channels include the ultra-rapidly activating, delayed outward-rectifying Kv1.5 channel conducting I Kur , the acetylcholine-activated inward-rectifying Kir3.1/Kir3.4 channel conducting I K,ACh , the Ca 2+ -activated K + channels of small conductance (SK) conducting I SK , and the two pore domain K + (K2P) channels TWIK-1, TASK-1 and TASK-3 that are responsible for voltage-independent background currents I TWIK-1 , I TASK-1 , and I TASK-3 . Here, we briefly review the characteristics of these K + channels and their roles in atrial fibrillation. The antiarrhythmic potential of drugs targeting the described channels is discussed as well as their putative value in treatment of atrial fibrillation. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. [Atrial fibrillation in elderly].

    Science.gov (United States)

    Arquizan, Caroline

    2012-11-01

    Atrial fibrilation (AF) is frequent and a strong risk factor for ischemic stroke in elderly. Ischemic stroke in patients with AF are more severe. Vitamine K antagonist therapy is highly effective for stroke prevention but is associated with hemorrhagic risk. The new oral anticoagulants (direct thrombin inhibitor [dabigatran], and direct factor Xa inhibitors [rivaroxaban and apixaban]) have all shown non inferiority or superiority, with better safety, considering the risk of intracranial haemorrhage. On this basis, it is justified to give them in priority in the vast majority of patients with AF, the choice of the drug and the dose is individual.

  20. Diagnosing Paroxysmal Atrial Fibrillation in Patients With Ischemic Strokes and Transient Ischemic Attacks Using Echocardiographic Measurements of Left Atrium Function

    DEFF Research Database (Denmark)

    Skaarup, Kristoffer Grundtvig; Christensen, Hanne Krarup; Høst, Nis

    2016-01-01

    Twenty-five to 35 percentage of stroke cases are cryptogenic, and it has been demonstrated that paroxysmal atrial fibrillation (AF) is the causal agent in up to 25% of these incidents. The purpose of this study was to investigate if left atrial (LA) parameters have value for diagnosing paroxysmal...... with paroxysmal AF. However, the atrial measurements evaluating LA function (min LA volume and LA emptying fraction) were significantly different (LA emptying fraction: 45% ± 10% vs 50% ± 10%, p = 0.004; minimal LA volume: 30.2 ml ± 17.3 ml vs 24 ml ± 10 ml, p = 0.035 in patients with paroxysmal AF, even after...

  1. Noninvasive evaluation of reverse atrial remodeling after catheter ablation of atrial fibrillation by P wave dispersion.

    Science.gov (United States)

    Fujimoto, Yuhi; Yodogawa, Kenji; Takahashi, Kenta; Tsuboi, Ippei; Hayashi, Hiroshi; Uetake, Shunsuke; Iwasaki, Yu-Ki; Hayashi, Meiso; Miyauchi, Yasushi; Shimizu, Wataru

    2017-11-01

    Atrial fibrillation (AF) itself creates structural and electrophysiological changes such as atrial enlargement, shortening of refractory period and decrease in conduction velocity, called "atrial remodeling", promoting its persistence. Although the remodeling process is considered to be reversible, it has not been elucidated in detail. The aim of this study was to assess the feasibility of P wave dispersion in the assessment of reverse atrial remodeling following catheter ablation of AF. Consecutive 126 patients (88 males, age 63.0 ± 10.4 years) who underwent catheter ablation for paroxysmal AF were investigated. P wave dispersion was calculated from the 12 lead ECG before, 1 day, 1 month, 3 months and 6 months after the procedure. Left atrial diameter (LAD), left atrial volume index (LAVI), left ventricular ejection fraction (LVEF), transmitral flow velocity waveform (E/A), and tissue Doppler (E/e') on echocardiography, plasma B-type natriuretic peptide (BNP) concentrations, serum creatinine, and estimated glomerular filtration rate (eGFR) were also measured. Of all patients, 103 subjects remained free of AF for 1 year follow-up. In these patients, P wave dispersion was not changed 1 day and 1 month after the procedure. However, it was significantly decreased at 3 and 6 months (50.1 ± 14.8 to 45.4 ± 14.4 ms, p < 0.05, 45.2 ± 9.9 ms, p < 0.05, respectively). Plasma BNP concentrations, LAD and LAVI were decreased (81.1 ± 103.8 to 44.8 ± 38.3 pg/mL, p < 0.05, 38.2 ± 5.7 to 35.9 ± 5.6 mm, p < 0.05, 33.3 ± 14.2 to 29.3 ± 12.3 mL/m 2 , p < 0.05) at 6 months after the procedure. There were no significant changes in LVEF, E/A, E/e', serum creatinine, and eGFR during the follow up period. P wave dispersion was decreased at 3 and 6 months after catheter ablation in patients without recurrence of AF. P wave dispersion is useful for assessment of reverse remodeling after catheter ablation of AF.

  2. ABO blood groups: A risk factor for left atrial and left atrial appendage thrombogenic milieu in patients with non-valvular atrial fibrillation.

    Science.gov (United States)

    Fu, Yuan; Li, Kuibao; Yang, Xinchun

    2017-08-01

    Previous studies have identified ABO blood groups as predictors of thromboembolic diseases. In patients with atrial fibrillation (AF), however, potential association between ABO blood groups and the risk of left atrial (LA) and/or left atrial appendage (LAA) thrombogenic milieu (TM) has not been established. This is a retrospective case-control study that included 125 consecutive patients with non-valvular atrial fibrillation (NVAF) plus TM, as evidenced by transesophageal echocardiography (TEE) during a period from1 January 2010 to 31 December 2016. The controls were selected randomly from 1072 NVAF without TM at a 1:2 ratio. Potential association between ABO blood groups and TM was analyzed using multivariate logistic regression analysis. The risk of TM was higher in patients with blood group A (33.6% vs. 20.2% in non-A blood groups, P=0.005). After adjusting for age, sex, oral anticoagulant use, AF type and duration, and relevant functional measures (e.g., NT-pro BNP level, left atrium diameter, and left ventricular ejection fraction), blood group A remained associated with an increased risk of TM (OR=2.99, 95% CI 1.4-6.388, P=0.005). Blood group A is an independent risk factor for TM in NVAF patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. 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......, and hospitalizations. During the fourth Atrial Fibrillation competence NETwork/European Heart Rhythm Association (AFNET/EHRA) consensus conference, we identified the following opportunities to personalize management of AF in a better manner with a view to improve outcomes by integrating atrial morphology and damage...

  4. Atrial and ventricular function after cardioversion of atrial fibrillation.

    Science.gov (United States)

    Xiong, C.; Sonnhag, C.; Nylander, E.; Wranne, B.

    1995-01-01

    OBJECTIVE--Previous studies on atrial recovery after cardioversion of atrial fibrillation have not taken into account new knowledge about the pathophysiology of transmitral and transtricuspid flow velocity patterns. It is possible to shed further light on this problem if atrioventricular inflow velocity, venous filling pattern, and atrioventricular annulus motion are recorded and interpreted together. DESIGN--Prospective examinations of mitral and tricuspid transvalvar flow velocities, superior caval and pulmonary venous filling, and mitral and tricuspid annulus motion were recorded using Doppler echocardiography. Examinations were performed before and 24 hours, 1 month, and 20 months after cardioversion. SETTING--Tertiary referral centre for cardiac disease with facilities for invasive and non-invasive investigation. PATIENTS--16 patients undergoing cardioversion of atrial fibrillation in whom sinus rhythm had persisted for 24 hours or more. RESULTS--Before conversion there was no identifiable A wave in transvalvar flow recordings. The total motion of the tricuspid and mitral annulus was subnormal and there was no identifiable atrial component. Venous flow patterns in general showed a low systolic velocity. After conversion, A waves and atrial components were seen in all patients and increased significantly (P atrial components, an increased systolic component of venous inflow, an increased A wave velocity, and a decreased E/A ratio of the transvalvar velocity curves. The ventricular component of annulus motion was unchanged. Changes in general occurred earlier on the right side than the left. CONCLUSIONS--This study indicates that, in addition to the previously known electromechanical dissociation of atrial recovery that exists after cardioversion of atrial fibrillation, there may also be a transient deterioration of ventricular function modulating the transvalvar inflow velocity recordings. Function on the right side generally becomes normal earlier than on the

  5. Atrial fibrillation and hyperthyroidism: A literature review.

    Science.gov (United States)

    Reddy, Vivek; Taha, Wael; Kundumadam, Shanker; Khan, Mazhar

    Atrial fibrillation is the most common arrhythmia worldwide with increasing frequency noted with age. Hyperthyroidism is a well-known cause of atrial fibrillation with a 16%-60% prevalence of atrial fibrillation in patients with known hyperthyroidism Ross et al. (2016). While hyperthyroidism as a causative factor of atrial fibrillation is well established, this literature review aims to answer several questions on this topic including: 1. The relationship of atrial fibrillation to hyperthyroidism 2. Atrial fibrillation as a predictor of hyperthyroidism 3. The pathophysiology of thyrotoxic atrial fibrillation 4. Subclinical hyperthyroidism and the relationship with atrial fibrillation 5. Cardioversion and Catheter ablation of hyperthyroid patients with atrial fibrillation 6. Thrombotic risk of hyperthyroid patients with atrial fibrillation 7. Management of Thyrotoxic Atrial fibrillation 8. Pharmacological rhythm control in patients with hyperthyroidism and atrial fibrillation 9. Treatment of Hyperthyroidism to prevent atrial fibrillation 10. Clinical Implications of Hyperthyroidism and Atrial Fibrillation. Copyright © 2017 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

  6. Surgical Treatment of Atrial Fibrillation in Patients with Rheumatic Valve Disease

    Directory of Open Access Journals (Sweden)

    Ernesto Koehler Chavez

    Full Text Available Abstract Objective: To assess heart rhythm and predictive factors associated with sinus rhythm after one year in patients with rheumatic valve disease undergoing concomitant surgical treatment of atrial fibrillation. Operative mortality, survival and occurrence of stroke after one year were also evaluated. Methods: Retrospective longitudinal observational study of 103 patients undergoing rheumatic mitral valve surgery and ablation of atrial fibrillation using uni- or bipolar radiofrequency between January 2013 and December 2014. Age, gender, functional class (NYHA, type of atrial fibrillation, EuroSCORE, duration of atrial fibrillation, stroke, left atrial size, left ventricular ejection fraction, cardiopulmonary bypass time, myocardial ischemia time and type of radiofrequency were investigated. Results: After one year, 66.3% of patients were in sinus rhythm. Sinus rhythm at hospital discharge, lower left atrial size in the preoperative period and bipolar radiofrequency were associated with a greater chance of sinus rhythm after one year. Operative mortality was 7.7%. Survival rate after one year was 92.3% and occurrence of stroke was 1%. Conclusion: Atrial fibrillation ablation surgery with surgical approach of rheumatic mitral valve resulted in 63.1% patients in sinus rhythm after one year. Discharge from hospital in sinus rhythm was a predictor of maintenance of this rhythm. Increased left atrium and use of unipolar radiofrequency were associated with lower chance of sinus rhythm. Operative mortality rate of 7.7% and survival and stroke-free survival contribute to excellent care results for this approach.

  7. Acute termination of human atrial fibrillation by identification and catheter ablation of localized rotors and sources: first multicenter experience of focal impulse and rotor modulation (FIRM) ablation.

    Science.gov (United States)

    Shivkumar, Kalyanam; Ellenbogen, Kenneth A; Hummel, John D; Miller, John M; Steinberg, Jonathan S

    2012-12-01

    Catheter ablation of atrial fibrillation (AF) currently relies on eliminating triggers, and no reliable method exists to map the arrhythmia itself to identify ablation targets. The aim of this multicenter study was to define the use of Focal Impulse and Rotor Modulation (FIRM) for identifying ablation targets. We prospectively enrolled the first (n = 14, 11 males) consecutive patients undergoing FIRM-guided ablation for persistent (n = 11) and paroxysmal AF at 5 centers. A 64-pole basket catheter was used for panoramic right and left atrial mapping during AF. AF electrograms were analyzed using a novel system to identify sustained rotors (spiral waves), or focal beats (centrifugal activation to surrounding atrium). Ablation was performed first at identified sources. The primary endpoints were acute AF termination or organization (>10% cycle length prolongation). Conventional ablation was performed only after FIRM-guided ablation. Twelve out of 14 cases were mapped. AF sources were demonstrated in all patients (average of 1.9 ± 0.8 per patient). Sources were left atrial in 18 cases, and right atrial in 5 cases, and 21/23 were rotors. FIRM-guided ablation achieved the acute endpoint in all patients, consisting of AF termination in n = 8 (4.9 ± 3.9 minutes at the primary source), and organization in n = 4. Total FIRM time for all patients was 12.3 ± 8.6 minutes. FIRM-guided ablation revealed localized AF rotors/focal sources in patients with paroxysmal, persistent and longstanding persistent AF. Brief targeted FIRM-guided ablation at a priori identified sites terminated or substantially organized AF in all cases prior to any other ablation. © 2012 Wiley Periodicals, Inc.

  8. Cryoballoon Ablation for Atrial Fibrillation

    Directory of Open Access Journals (Sweden)

    Jason G. Andrade, MD

    2012-03-01

    Full Text Available Focal point-by-point radiofrequency catheter ablation has shown considerable success in the treatment of paroxysmal atrial fibrillation. However, it is not without limitations. Recent clinical and preclinical studies have demonstrated that cryothermal ablation using a balloon catheter (Artic Front©, Medtronic CryoCath LP provides an effective alternative strategy to treating atrial fibrillation. The objective of this article is to review efficacy and safety data surrounding cryoballoon ablation for paroxysmal and persistent atrial fibrillation. In addition, a practical step-by-step approach to cryoballoon ablation is presented, while highlighting relevant literature regarding: 1 the rationale for adjunctive imaging, 2 selection of an appropriate cryoballoon size, 3 predictors of efficacy, 4 advanced trouble-shooting techniques, and 5 strategies to reduce procedural complications, such as phrenic nerve palsy.

  9. The Relationship between Left Atrial Mechanical Function and Functional Capacity in Mitral Stenosis

    Directory of Open Access Journals (Sweden)

    Mücahit Yetim

    2013-11-01

    Full Text Available Aim: In this study, left atrial functions of patients with rheumatic mitral stenosis and sinus rhythm, which was determined by transthorasic echocardiography, was compared with those of healhty subjects and the association of left atrial functions with functional capacity was investigated in subgroup analyses.   Material and methods: 32 patients with isolated rheumatic mitral stenosis (median age was 39.1±11  (group 1 and 20 patients in the control group ( median age was 37±8,2 (group 2 were enrolled to study. The average mitral valve area of patients was 1.1±0,3 cm2. When patients were divided according to New York Heart Association (NYHA classification ; 16 patients were NYHA 2 (Grup A and 16 patients were NYHA 3 (Grup B. There were not any asymptomatic patients and no patients were NYHA 4. Left atrium diameters, left atrium volume, left atrium fractional area change and left atrium ejection fractions  of patients in these groups were calculated.   Results: The demographic characteristics of patients is shown in table 1. Left atrium ejection fraction (LAEF and left atrium fractional area change (LAFAC that were determined echocardiographycally were significantly lower in patients with mitral stenosis (32 ± 5, 44 ± 3; p<0.001- 25 ± 11, 32 ± 6; p< 0.02.  When patients were divided according to New York Heart Association (NYHA classification ; 16 patients were NYHA 2 (Grup A and 16 patients were NYHA 3 (Grup B. There were not any asymptomatic patients and no patients were NYHA 4. The clinical and echocardiographic data of patients are shown in table 2. Despite of similar mitral valve area and average mitral gradient ,systolic pulmonary artery pressure was found to be higher in symptomatic group. But there was no difference between left atrial functions of the two groups.   Discussion: In this study we have shown that left atrial functions determined echocardiographically  can decline in patients with mitral stenosis but the

  10. 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.

  11. Changes in left atrial deformation in hypertrophic cardiomyopathy: Evaluation by vector velocity imaging

    Directory of Open Access Journals (Sweden)

    Hala Mahfouz Badran

    2012-12-01

    Full Text Available Objectives: Hypertrophic cardiomyopathy (HCM represents a generalized myopathic process affecting both ventricular and atrial myocardium. We assessed the global and regional left atrial (LA function and its relation to left ventricular (LV mechanics and clinical status in patients with HCM using Vector Velocity Imaging (VVI. Methods: VVI of the LA and LV was acquired from apical four- and two-chamber views of 108 HCM patients (age 40±19years, 56.5% men and 33 healthy subjects, all had normal LV systolic function. The LA subendocardium was traced to obtain atrial volumes, ejection fraction, velocities, and strain (ɛ/strain rate (SR measurements. Results: Left atrial reservoir (ɛsys,SRsys and conduit (early diastolic SRe function were significantly reduced in HCM compared to controls (P-1.8s-1 was 81% sensitive and 30% specific, SRa>-1.5s-1 was 73% sensitive and 40% specific. By multivariate analysis global LVɛsys and LV septal thickness are independent predictors for LAɛsys, while end systolic diameter is the only independent predictor for SRsys, P<.001. Conclusion: Left atrial reservoir and conduit function as measured by VVI were significantly impaired while contractile function was preserved among HCM patients. Left atrial deformation was greatly influenced by LV mechanics and correlated to severity of phenotype.

  12. Changes in left atrial deformation in hypertrophic cardiomyopathy: Evaluation by vector velocity imaging

    Science.gov (United States)

    Badran, Hala Mahfouz; Soltan, Ghada; Hassan, Hesham; Nazmy, Ahmed; Faheem, Naglaa; Saadan, Haythem; Yacoub, Magdi H.

    2012-01-01

    Abstract: Objectives: Hypertrophic cardiomyopathy (HCM) represents a generalized myopathic process affecting both ventricular and atrial myocardium. We assessed the global and regional left atrial (LA) function and its relation to left ventricular (LV) mechanics and clinical status in patients with HCM using Vector Velocity Imaging (VVI). Methods: VVI of the LA and LV was acquired from apical four- and two-chamber views of 108 HCM patients (age 40 ± 19years, 56.5% men) and 33 healthy subjects, all had normal LV systolic function. The LA subendocardium was traced to obtain atrial volumes, ejection fraction, velocities, and strain (ϵ)/strain rate (SR) measurements. Results: Left atrial reservoir (ϵsys,SRsys) and conduit (early diastolic SRe) function were significantly reduced in HCM compared to controls (P  − 1.8s− 1 was 81% sensitive and 30% specific, SRa> − 1.5s− 1 was 73% sensitive and 40% specific. By multivariate analysis global LVϵsys and LV septal thickness are independent predictors for LAϵsys, while end systolic diameter is the only independent predictor for SRsys, P < .001. Conclusion: Left atrial reservoir and conduit function as measured by VVI were significantly impaired while contractile function was preserved among HCM patients. Left atrial deformation was greatly influenced by LV mechanics and correlated to severity of phenotype. PMID:24688992

  13. Failed anti-tachycardia pacing can be used to differentiate atrial arrhythmias from ventricular tachycardia in implantable cardioverter-defibrillators.

    Science.gov (United States)

    Michael, Kevin A; Enriquez, Andres; Baranchuk, Adrian; Haley, Charlotte; Caldwell, Jane; Simpson, Christopher S; Abdollah, Hoshiar; Redfearn, Damian P

    2015-01-01

    Atrial fibrillation/tachycardia (AF/AT) may result in inappropriate therapies in implantable cardioverter-defibrillators (ICDs). The post-pacing interval (PPI) and tachycardia cycle length difference (PPI - TCL) has been previously demonstrated to indicate the proximity of the pacing site to a tachycardia origin. We postulated that the PPI and PPI - TCL would be greater in AT/AF vs. ventricular tachycardia (VT) after episodes of failed anti-tachycardia pacing (ATP). This was a single-centre, retrospective study evaluating consecutive patients implanted with dual (DR)/biventricular (BIV) ICDs. Stored electrograms were used to determine whether the ATP captured the arrhythmia and the arrhythmia did not present with primary or secondary termination. Measurements were done using manual calipers. A total of 155 patients were included. There were 79 BIV and 76 DR devices. In total, 39 episodes were identified in 20 patients over a 23-month follow-up period. A total of 76 sequences of ATP (burst/ramp) were delivered, 28 (37%) of them inappropriate. Fifty-one events (18 AT/AF and 33 VT) were compared. The mean PPI was 693 ± 96 vs. 512 ± 88 ms (P failed ATP differs significantly between AF/AT and VT and are therefore useful indices to discriminate between supraventricular tachycardia and VT in ICDs. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

  14. Effect of mitral regurgitation on cerebrovascular accidents in patients with atrial fibrillation and left atrial thrombus.

    Science.gov (United States)

    Nair, Chandra K; Aronow, Wilbert S; Shen, Xuedong; Anand, Kishlay; Holmberg, Mark J; Esterbrooks, Dennis J

    2009-11-01

    The effect of mitral regurgitation (MR) on the incidence of new cerebrovascular accidents (CVA) and mortality in patients with atrial fibrillation (AF) and left atrial thrombus (LAT) is unknown. To investigate the effect of MR in patients with AF and LAT on new CVA and mortality. Eighty nine consecutive patients, mean age 71 years, with AF and LAT documented by transesophageal echocardiography were investigated to determine the prevalence and severity of MR and the association of the severity of MR with new cerebrovascular accidents (CVA) and mortality at 34-mo follow-up. Of 89 patients, 1 + MR was present in 23 patients (26%), 2 + MR in 44 patients (50%), 3 + MR in 17 patients (19%), and 4 + MR in 3 patients (4%). Mean follow-up was 34 +/- 28 mo. The Cox proportional hazards model showed that the severity of increased MR did not significantly increase new CVA or mortality at 34-mo follow-up. The only variable predictive of mortality was left ventricular ejection fraction (LVEF), and with every unit increase in LVEF, the risk decreased by 3%. MR occurred in 87 of 89 patients (98%) with AF and LAT. There was no association between the severity of MR and the incidence of CVA or mortality.

  15. Evaluation of single right atrial volume and function with magnetic resonance imaging in children with hypoplastic left heart

    Energy Technology Data Exchange (ETDEWEB)

    Vijarnsorn, Chodchanok [University of Alberta, Faculty of Medicine and Dentistry, Stollery Children' s Hospital, Edmonton, AB (Canada); Mahidol University, Siriraj Hospital, Bangkok (Thailand); Myers, Kimberley; Patton, David J. [Alberta Children' s Hospital, Section of Pediatric Cardiology, Department of Pediatrics, Department of Pediatrics, Calgary, AB (Canada); Noga, Michelle; Crawley, Cinzia; Tham, Edythe [University of Alberta, Faculty of Medicine and Dentistry, Stollery Children' s Hospital, Edmonton, AB (Canada)

    2016-06-15

    Standardized methods to evaluate atrial properties in single ventricles are lacking. To determine the feasibility of quantifying right atrial volumes and function in hypoplastic left heart using MRI. We studied 15 infants with hypoplastic left heart prior to Glenn surgery (mean age 4.2 months [standard deviation 0.3]) who underwent cardiac MRI with evaluation of atrial volumes and emptying fraction using monoplane two-chamber, monoplane four-chamber, and biplane methods, all of which were compared to the atrial short-axial oblique stack method. We compared atrial end-diastolic volume, end-systolic volume and emptying fraction among these methods. We analyzed reproducibility of the methods using Bland-Altman plots. Both four-chamber and biplane methods showed high correlations for atrial end-diastolic volume (r = 0.7 and r = 0.8, respectively; P < 0.01) and end-systolic volume (r = 0.8 and r = 0.9, respectively; P < 0.01) with small mean differences (-0.2 ± 2.9 standard deviation [SD] ml and -0.8 ± 1.6 ml, respectively, for atrial end-diastolic volume and -0.8 ± 1.5 ml and -0.9 ± 0.9 ml, respectively, for atrial end-systolic volume). The short-axial oblique method was the most reproducible, followed by the four-chamber method. MRI assessment of atrial volume and function is feasible in hypoplastic left heart and might provide further insight into single-ventricle mechanics. (orig.)

  16. [Echocardiographic factors predictive of restoration and maintenance of sinus rhythm after reduction of atrial fibrillation].

    Science.gov (United States)

    Ben Khalfallah, A; Sanaa, I

    2007-09-01

    Atrial fibrillation (AF) is the most common cardiac arrhythmia. While the arrhythmia was initially thought to be little more than a nuisance, it is now clear that AF has a significant negative impact on quality of life and a corresponding increase in both morbidity and mortality. The aim of this study was to identify Doppler echographic patterns that allow prediction of atrial fibrillation reduction and maintenance of sinus rhythm within 12 months. One hundred and thirty patients having permanent atrial fibrillation, recent (51) or chronic (79) are included in the study, excepting those with valvular heart disease or thyroid dysfunction. The mean age was 63.5 +/- 11.3 years. Both transthoracic and transoesophageal echocardiography was performed using a Philips SONOS 5500 Echograph, before cardioversion. Were studied: end diastolic and systolic left ventricular diameters, left ventricular ejectionnal fraction, left atrial area (LAA), left atrial diameter, left atrial appendage area and peak emptying velocities of the left atrial appendage (PeV). Sinus rhythm was re-established in 102 patients (44 having recent and 58 chronic atrial fibrillation). Sinus rhythm was maintained for 12 months in 79 patients. Within the echographic parameters studied, the left atrial area (LAA) and peak emptying velocities of left atrial appendage (PeV) before cardioversion were the best predictors of restoration of sinus rhythm. On monovariate analysis, SOG is significantly lower and PicV is significantly higher in patients whose sinus rhythm had been restored in comparison with those with permanent atrial fibrillation. (Mean SOG: 27.7 +/- 7.62 vs. 34 +/- 7,6 cm2, ppredict on mono and multivariate analysis (p=0.05, OR=0.5, IC=0.36 à 3.56), re-establishing of sinus rhythm whereas in patients with chronic atrial fibrillation, peak emptying velocity of left atrial appendage predict better re-establishing of sinus rhythm (p=0.04, OR=1.29, IC=0.12 à 4.23). The threshold values of LAA and Pe

  17. Stroke prevention in atrial fibrillation

    DEFF Research Database (Denmark)

    Fanaroff, Alexander C; Steffel, Jan; Alexander, John H

    2018-01-01

    of anticoagulation for atrial fibrillation (AF). Observational studies employing RWD are useful for describing how oral anticoagulants are used in clinical practice, but generally cannot be used to make claims regarding comparative treatment effects. Questions regarding treatment effect generally are best answered...

  18. 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.

  19. High-voltage zones within the pulmonary vein antra: Major determinants of acute pulmonary vein reconnections after atrial fibrillation ablation.

    Science.gov (United States)

    Nagashima, Koichi; Watanabe, Ichiro; Okumura, Yasuo; Iso, Kazuki; Takahashi, Keiko; Watanabe, Ryuta; Arai, Masaru; Kurokawa, Sayaka; Nakai, Toshiko; Ohkubo, Kimie; Yoda, Shunichi; Hirayama, Atsushi

    2017-08-01

    Recurrence of atrial fibrillation (AF) after pulmonary vein isolation (PVI) is mainly due to PV reconnections. Patient-specific tissue characteristics that may contribute remain unidentified. This study aimed to assess the relationship between the bipolar electrogram voltage amplitudes recorded from the PV-left atrial (LA) junction and acute PV reconnection sites. Three-dimensional LA voltage maps created before an extensive encircling PVI in 47 AF patients (31 men; mean age 62 ± 11 years) were examined for an association between the EGM voltage amplitude recorded from the PV-LA junction and acute post-PVI PV reconnections (spontaneous PV reconnections and/or ATP-provoked dormant PV conduction). Acute PV reconnections were observed in 17 patients (36%) and in 24 (3%) of the 748 PV segments (16 segments per patient) and were associated with relatively high bipolar voltage amplitudes (3.26 ± 0.85 vs. 1.79 ± 1.15 mV, p voltage (137 [106, 166] vs. 295 [193, 498] gs/mV, p voltage and FTI/PV-LA bipolar voltage for acute PV reconnections (areas under the curve: 0.86 and 0.89, respectively); the best cutoff values were >2.12 mV and ≤183 gs/mV, respectively. The PV-LA voltage on the PV-encircling ablation line and FTI/PV-LA voltage were related to the acute post-PVI PV reconnections. A more durable ablation strategy is warranted for high-voltage zones.

  20. Isthmus sites identified by Ripple Mapping are usually anatomically stable: A novel method to guide atrial substrate ablation?

    Science.gov (United States)

    Luther, Vishal; Qureshi, Norman; Lim, Phang Boon; Koa-Wing, Michael; Jamil-Copley, Shahnaz; Ng, Fu Siong; Whinnett, Zachary; Davies, D Wyn; Peters, Nicholas S; Kanagaratnam, Prapa; Linton, Nick

    2018-03-01

    Postablation reentrant ATs depend upon conducting isthmuses bordered by scar. Bipolar voltage maps highlight scar as sites of low voltage, but the voltage amplitude of an electrogram depends upon the myocardial activation sequence. Furthermore, a voltage threshold that defines atrial scar is unknown. We used Ripple Mapping (RM) to test whether these isthmuses were anatomically fixed between different activation vectors and atrial rates. We studied post-AF ablation ATs where >1 rhythm was mapped. Multipolar catheters were used with CARTO Confidense for high-density mapping. RM visualized the pattern of activation, and the voltage threshold below which no activation was seen. Isthmuses were characterized at this threshold between maps for each patient. Ten patients were studied (Map 1 was AT1; Map 2: sinus 1/10, LA paced 2/10, AT2 with reverse CS activation 3/10; AT2 CL difference 50 ± 30 ms). Point density was similar between maps (Map 1: 2,589 ± 1,330; Map 2: 2,214 ± 1,384; P  =  0.31). RM activation threshold was 0.16 ± 0.08 mV. Thirty-one isthmuses were identified in Map 1 (median 3 per map; width 27 ± 15 mm; 7 anterior; 6 roof; 8 mitral; 9 septal; 1 posterior). Importantly, 7 of 31 (23%) isthmuses were unexpectedly identified within regions without prior ablation. AT1 was treated following ablation of 11/31 (35%) isthmuses. Of the remaining 20 isthmuses, 14 of 16 isthmuses (88%) were consistent between the two maps (four were inadequately mapped). Wavefront collision caused variation in low voltage distribution in 2 of 16 (12%). The distribution of isthmuses and nonconducting tissue within the ablated left atrium, as defined by RM, appear concordant between rhythms. This could guide a substrate ablative approach. © 2018 Wiley Periodicals, Inc.

  1. Impaired atrial electromechanical function and atrial fibrillation promotion in alloxan-induced diabetic rabbits.

    Science.gov (United States)

    Fu, Huaying; Liu, Changle; Li, Jian; Zhou, Changyu; Cheng, Lijun; Liu, Tong; Li, Guangping

    2013-01-01

    Diabetes mellitus (DM) is an independent risk factor for atrial fibrillation (AF). However, the underlying mechanisms are still not clearly elucidated. The aim of this study was to evaluate the atrial electromechanical function, atrial electrophysiological changes and AF inducibility in alloxan-induced diabetic rabbits. In 8 alloxan-induced diabetic rabbits and 8 controls, we evaluated atrial electromechanical function by tissue Doppler imaging. Isolated Langendorff-perfused rabbit hearts were prepared to measure atrial refractory effective period (AERP) and its dispersion (AERPD), interatrial conduction time (IACT) and vulnerability to AF. Atrial interstitial fibrosis was evaluated by Sirius-Red staining. Compared with controls, left atrial lateral wall Pa'-start interval (Pastart) and right atrial wall Pastart were increased in diabetic rabbits. AERPD was increased and IACT was prolonged in diabetic rabbits. Inducibility of AF in diabetic group was significant higher than controls (6/8 vs. 1/8, p TEMA); left atrial lateral wall Papeak and TEMA, left atrial posterior wall TEMA, and IACT were correlated with atrial areas of fibrosis. Atrial electromechanical function is impaired in diabetic rabbits, and is associated with atrial fibrosis and interatrial electrical conduction delay.

  2. Effects of postshock atrial pacing on atrial defibrillation outcome in the isolated sheep heart

    NARCIS (Netherlands)

    Skanes, A. C.; Gray, R. A.; Zuur, C. L.; Jalife, J.

    1998-01-01

    BACKGROUND: Failed atrial defibrillation shocks are associated with organization of postshock activity and a substantial postshock electrical quiescence. We investigated the ability of a train of pacing stimuli to capture or locally entrain atrial myocardium during the quiescent period after

  3. Management of atrial fibrillation in the setting of heart failure

    NARCIS (Netherlands)

    Crijns, HJGM; VandenBerg, MP; VanGelder, IC; VanVeldhuisen, DJ

    Heart failure is often complicated by atrial fibrillation. Once atrial fibrillation has started it further enhances heart failure due to uncontrolled rate with shortened filling time and provocation of tachycardiomyopathy. Absent atrial kick and irregularity of the ventricular rhythm also

  4. FRACTIONAL BANKING

    OpenAIRE

    Maria Klimikova

    2010-01-01

    Understanding the reasons of the present financial problems lies In understanding the substance of fractional reserve banking. The substance of fractional banking is in lending more money than the bankers have. Banking of partial reserves is an alternative form which links deposit banking and credit banking. Fractional banking is causing many unfavorable economic impacts in the worldwide system, specifically an inflation.

  5. Right Atrial Deformation in Predicting Outcomes in Pediatric Pulmonary Hypertension.

    Science.gov (United States)

    Jone, Pei-Ni; Schäfer, Michal; Li, Ling; Craft, Mary; Ivy, D Dunbar; Kutty, Shelby

    2017-12-01

    Elevated right atrial (RA) pressure is a risk factor for mortality, and RA size is prognostic of adverse outcomes in pulmonary hypertension (PH). There is limited data on phasic RA function (reservoir, conduit, and pump) in pediatric PH. We sought to evaluate (1) the RA function in pediatric PH patients compared with controls, (2) compare the RA deformation indices with Doppler indices of diastolic dysfunction, functional capacity, biomarkers, invasive hemodynamics, and right ventricular functional indices, and (3) evaluate the potential of RA deformation indices to predict clinical outcomes. Sixty-six PH patients (mean age 7.9±4.7 years) were compared with 36 controls (7.7±4.4 years). RA and right ventricular deformation indices were obtained using 2-dimensional speckle tracking (2DCPA; TomTec, Germany). RA strain, strain rates, emptying fraction, and right ventricular longitudinal strain were measured. RA function was impaired in PH patients versus controls ( P right ventricular diastolic dysfunction. RA reservoir function, pump function, the rate of atrial filling, and atrial minimum volume emerged as outcome predictors in pediatric PH. © 2017 American Heart Association, Inc.

  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. [Relations between FANS, PPI and atrial fibrillation].

    Science.gov (United States)

    Ricci, Fabrizio; De Caterina, Raffaele

    2013-05-01

    Recent evidence supports the existence of an association between the use of non-steroidal anti-inflammatory drugs and the risk of atrial fibrillation. Anti-inflammatory drugs are widely used for the treatment of systemic inflammatory disorders, and chronic inflammation is a well-known risk factor for the development of myocardial fibrosis. The latter accounts for atrial inhomogeneities of conduction, thus triggering and perpetuating atrial fibrillation. Atrial inflammatory remodeling may therefore be responsible for the higher incidence of atrial fibrillation among patients assuming steroidal and non-steroidal anti-inflammatory drugs because of an underlying inflammatory disorders. Alternative theories contemplate gastroesophageal reflux, which is extremely common during the use of non-steroidal anti-inflammatory drugs and may trigger atrial fibrillation, as mediating the above-mentioned association.

  8. Surgical treatment for ectopic atrial tachycardia.

    Science.gov (United States)

    Graffigna, A; Vigano, M; Pagani, F; Salerno, G

    1992-08-01

    Atrial tachycardia is an infrequent but potentially dangerous arrhythmia which often determines cardiac enlargement. Surgical ablation of the arrhythmia is effective and safe, provided a careful atrial mapping is performed and the surgical technique is tailored to the individual focus location. Eight patients underwent surgical ablation of ectopic atrial tachycardia between 1977 and 1990. Different techniques were adopted for each patient according to the anatomical location of the focus and possibly associated arrhythmias. Whenever possible, a closed heart procedure was chosen. In 1 patient a double focal origin was found and treated by separate procedures. In 1 patient with ostium secundum atrial septal defect and atrial flutter, surgical isolation of the right appendage and the ectopic focus was performed. In all patients ectopic atrial tachycardia was ablated with maintenance of the sinoatrial and atrioventricular nodal function as well as internodal conduction. In follow-up up to December 1991, no recurrency was recorded.

  9. 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.

  10. Evaluating the Atrial Myopathy Underlying Atrial Fibrillation: Identifying the Arrhythmogenic and Thrombogenic Substrate

    Science.gov (United States)

    Goldberger, Jeffrey J.; Arora, Rishi; Green, David; Greenland, Philip; Lee, Daniel C.; Lloyd-Jones, Donald M.; Markl, Michael; Ng, Jason; Shah, Sanjiv J.

    2015-01-01

    Atrial disease or myopathy forms the substrate for atrial fibrillation (AF) and underlies the potential for atrial thrombus formation and subsequent stroke. Current diagnostic approaches in patients with AF focus on identifying clinical predictors with evaluation of left atrial size by echocardiography serving as the sole measure specifically evaluating the atrium. Although the atrial substrate underlying AF is likely developing for years prior to the onset of AF, there is no current evaluation to identify the pre-clinical atrial myopathy. Atrial fibrosis is one component of the atrial substrate that has garnered recent attention based on newer MRI techniques that have been applied to visualize atrial fibrosis in humans with prognostic implications regarding success of treatment. Advanced ECG signal processing, echocardiographic techniques, and MRI imaging of fibrosis and flow provide up-to-date approaches to evaluate the atrial myopathy underlying AF. While thromboembolic risk is currently defined by clinical scores, their predictive value is mediocre. Evaluation of stasis via imaging and biomarkers associated with thrombogenesis may provide enhanced approaches to assess risk for stroke in patients with AF. Better delineation of the atrial myopathy that serves as the substrate for AF and thromboembolic complications might improve treatment outcomes. Furthermore, better delineation of the pathophysiologic mechanisms underlying the development of the atrial substrate for AF, particularly in its earlier stages, could help identify blood and imaging biomarkers that could be useful to assess risk for developing new onset AF and suggest specific pathways that could be targeted for prevention. PMID:26216085

  11. Digoxin versus placebo, no intervention, or other medical interventions for atrial fibrillation and atrial flutter

    DEFF Research Database (Denmark)

    Sethi, Naqash; Safi, Sanam; Feinberg, Joshua

    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 fibrillati...

  12. Persistent atrial fibrillation vs paroxysmal atrial fibrillation: differences in management.

    Science.gov (United States)

    Margulescu, Andrei D; Mont, Lluis

    2017-08-01

    Atrial fibrillation (AF) is the most common human arrhythmia. AF is a progressive disease, initially being nonsustained and induced by trigger activity, and progressing towards persistent AF through alteration of the atrial myocardial substrate. Treatment of AF aims to decrease the risk of stroke and improve the quality of life, by preventing recurrences (rhythm control) or controlling the heart rate during AF (rate control). In the last 20 years, catheter-based and, less frequently, surgical and hybrid ablation techniques have proven more successful compared with drug therapy in achieving rhythm control in patients with AF. However, the efficiency of ablation techniques varies greatly, being highest in paroxysmal and lowest in long-term persistent AF. Areas covered: In this review, we discuss the fundamental differences between paroxysmal and persistent AF and the potential impact of those differences on patient management, emphasizing the available therapeutic strategies to achieve rhythm control. Expert commentary: Treatment to prevent AF recurrences is suboptimal, particularly in patients with persistent AF. Emerging technologies, such as documentation of atrial fibrosis using magnetic resonance imaging and documentation of electrical substrate using advanced electrocardiographic imaging techniques are likely to provide valuable insights about patient-specific tailoring of treatments.

  13. Fractional thermoelasticity

    CERN Document Server

    Povstenko, Yuriy

    2015-01-01

    This book is devoted to fractional thermoelasticity, i.e. thermoelasticity based on the heat conduction equation with differential operators of fractional order. Readers will discover how time-fractional differential operators describe memory effects and space-fractional differential operators deal with the long-range interaction. Fractional calculus, generalized Fourier law, axisymmetric and central symmetric problems and many relevant equations are featured in the book. The latest developments in the field are included and the reader is brought up to date with current research.  The book contains a large number of figures, to show the characteristic features of temperature and stress distributions and to represent the whole spectrum of order of fractional operators.  This work presents a picture of the state-of-the-art of fractional thermoelasticity and is suitable for specialists in applied mathematics, physics, geophysics, elasticity, thermoelasticity and engineering sciences. Corresponding sections of ...

  14. Atrial Fibrillation Ablation in Systolic Dysfunction: Clinical and Echocardiographic Outcomes

    Directory of Open Access Journals (Sweden)

    Tasso Julio Lobo

    2015-01-01

    Full Text Available Background: Heart failure and atrial fibrillation (AF often coexist in a deleterious cycle. Objective: To evaluate the clinical and echocardiographic outcomes of patients with ventricular systolic dysfunction and AF treated with radiofrequency (RF ablation. Methods: Patients with ventricular systolic dysfunction [ejection fraction (EF <50%] and AF refractory to drug therapy underwent stepwise RF ablation in the same session with pulmonary vein isolation, ablation of AF nests and of residual atrial tachycardia, named "background tachycardia". Clinical (NYHA functional class and echocardiographic (EF, left atrial diameter data were compared (McNemar test and t test before and after ablation. Results: 31 patients (6 women, 25 men, aged 37 to 77 years (mean, 59.8±10.6, underwent RF ablation. The etiology was mainly idiopathic (19 p, 61%. During a mean follow-up of 20.3±17 months, 24 patients (77% were in sinus rhythm, 11 (35% being on amiodarone. Eight patients (26% underwent more than one procedure (6 underwent 2 procedures, and 2 underwent 3 procedures. Significant NYHA functional class improvement was observed (pre-ablation: 2.23±0.56; postablation: 1.13±0.35; p<0.0001. The echocardiographic outcome also showed significant ventricular function improvement (EF pre: 44.68%±6.02%, post: 59%±13.2%, p=0.0005 and a significant left atrial diameter reduction (pre: 46.61±7.3 mm; post: 43.59±6.6 mm; p=0.026. No major complications occurred. Conclusion: Our findings suggest that AF ablation in patients with ventricular systolic dysfunction is a safe and highly effective procedure. Arrhythmia control has a great impact on ventricular function recovery and functional class improvement.

  15. Metabolic Syndrome Is Associated with Atrial Electrical and Mechanical Dysfunction

    Science.gov (United States)

    Yilmaz, Hale; Özcan, Kazım Serhan; Sayar, Nurten; Kemaloglu, Tugba; Gungor, Baris; Erer, Betul; Yilmaz, Mehmet; Gurkan, Ufuk; Cakmak, Nazmiye; Oz, Dilaver; Calik, Ali Nazmi; Bolca, Osman

    2015-01-01

    Objective In this study, we aimed to investigate the left atrial (LA) electrical and mechanical functions in patients with metabolic syndrome (MetS). Subjects and Methods The study population consisted of 87 patients with MetS and 67 controls. Intra-atrial and interatrial electromechanical delays (EDs) were measured with tissue Doppler imaging. P-wave dispersion (Pd) was calculated from the 12-lead electrocardiograms. LA volumes were measured echocardiographically by the biplane area-length method. Results Intra-atrial and interatrial EDs and Pd were significantly higher in patients with MetS (10.3 ± 6.3, 21.0 ± 11.5 and 41.7 ± 10.8) than in controls (7.4 ± 5.5, 12.3 ± 10.4 and 29.2 ± 7.4; p = 0.003, p < 0.001 and p < 0.001, respectively). The LA preatrial contraction volume and active emptying volumes were higher in this population, but the LA passive emptying fraction was lower. In the multivariate linear regression analysis, the presence of MetS, LA active emptying volume and left ventricular early diastolic (E) wave velocity/late diastolic (A) wave velocity (E/A) ratios were independent correlates of interatrial ED (p = 0.002, p = 0.001 and p = 0.025, respectively). Conclusions This study showed that intra-atrial and interatrial EDs and Pd were prolonged and LA mechanical functions were impaired in patients with MetS. PMID:25592764

  16. [Panic disorder and atrial fibrillation].

    Science.gov (United States)

    Olazabal Eizaguirre, N; Chavez, R; González-Torres, M A; Gaviria, M

    2013-10-01

    This paper studies the relationship between atrial fibrillation and panic disorder. There are often doubts on the differential diagnosis in emergency services and general medical settings. Panic disorder prevalence rates have been found to be high in patients suffering from atrial fibrillation. Various studies have observed that patients diagnosed with anxiety disorders frequently have higher cardiovascular disease rates compared to the general population. Usually, patients suffering from panic disorder exhibit somatic complaints suggesting coronary disease, such as chest pain or palpitations. The aim is to make the correct diagnosis and treatment for these different illnesses, and to decrease the costs due to misdiagnosis. Copyright © 2012 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España. All rights reserved.

  17. Relevance of Electrical Remodeling in Human Atrial Fibrillation Results of the Asymptomatic Atrial Fibrillation and Stroke Evaluation in Pacemaker Patients and the Atrial Fibrillation Reduction Atrial Pacing Trial Mechanisms of Atrial Fibrillation Study

    NARCIS (Netherlands)

    Healey, Jeff S.; Israel, Carsten W.; Connolly, Stuart J.; Hohnloser, Stefan H.; Nair, Girish M.; Divakaramenon, Syamkumar; Capucci, Alessandro; Van Gelder, Isabelle C.; Lau, Chu-Pak; Gold, Michael R.; Carlson, Mark; Themeles, Ellison; Morillo, Carlos A.

    Background-In animal models of atrial fibrillation (AF), changes in atrial electrophysiological properties are associated with the development of AF. Their relevance to human AF is unclear. Methods and Results-The Asymptomatic Atrial Fibrillation and Stroke Evaluation in Pacemaker Patients and the

  18. Atrial Function in Patients with Breast Cancer After Treatment with Anthracyclines

    Directory of Open Access Journals (Sweden)

    Yalin Tolga Yaylali

    Full Text Available Abstract Background: Atrial electromechanical delay (EMD is used to predict atrial fibrillation, measured by echocardiography. Objectives: The aim of this study was to assess atrial EMD and mechanical function after anthracycline-containing chemotherapy. Methods: Fifty-three patients with breast cancer (48 ± 8 years old who received 240 mg/m2of Adriamycin, 2400 mg/m2 of cyclophosphamide, and 960 mg/m2 of paclitaxel were included in this retrospective study, as were 42 healthy subjects (47 ± 9 years old. Echocardiographic measurements were performed 11 ± 7 months (median 9 months after treatment with anthracyclines. Results: Left intra-atrial EMD (11.4 ± 6.0 vs. 8.1 ± 4.9, p=0.008 and inter-atrial EMD (19.7 ± 7.4 vs. 14.7 ± 6.5, p=0.001 were prolonged; LA passive emptying volume and fraction were decreased (p=0.0001 and p=0.0001; LA active emptying volume and fraction were increased (p=0.0001 and p=0.0001; Mitral A velocity (0.8 ± 0.2 vs. 0.6 ± 0.2, p=0.0001 and mitral E-wave deceleration time (201.2 ± 35.6 vs. 163.7 ± 21.8, p=0.0001 were increased; Mitral E/A ratio (1.0 ± 0.3 vs. 1.3 ± 0.3, p=0.0001 and mitral Em (0.09 ± 0.03 vs. 0.11 ± 0.03, p=0.001 were decreased; Mitral Am (0.11 ± 0.02 vs. 0.09 ± 0.02, p=0.0001 and mitral E/Em ratio (8.8 ± 3.2 vs. 7.6 ± 2.6, p=0.017 were increased in the patients. Conclusions: In patients with breast cancer after anthracycline therapy: Left intra-atrial, inter-atrial electromechanical intervals were prolonged. Diastolic function was impaired. Impaired left ventricular relaxation and left atrial electrical conduction could be contributing to the development of atrial arrhythmias.

  19. Atrial fibrillation after cardiac surgery

    Directory of Open Access Journals (Sweden)

    Nair Suresh

    2010-01-01

    Full Text Available Once considered as nothing more than a nuisance after cardiac surgery, the importance of postoperative atrial fibrillation (POAF has been realized in the last decade, primarily because of the morbidity associated with the condition. Numerous causative factors have been described without any single factor being singled out as the cause of this complication. POAF has been associated with stroke, renal failure and congestive heart failure, although it is difficult to state whether POAF is directly responsible for these complications. Guidelines have been formulated for prevention of POAF. However, very few cardiothoracic centers follow any form of protocol to prevent POAF. Routine use of prophylaxis would subject all patients to the side effects of anti-arrhythmic drugs, while only a minority of the patients do actually develop this problem postoperatively. Withdrawal of beta blockers in the postoperative period has been implicated as one of the major causes of POAF. Amiodarone, calcium channel blockers and a variety of other pharmacological agents have been used for the prevention of POAF. Atrial pacing is a non-pharmacological measure which has gained popularity in the prevention of POAF. There is considerable controversy regarding whether rate control is superior to rhythm control in the treatment of established atrial fibrillation (AF. Amiodarone plays a central role in both rate control and rhythm control in postoperative AF. Newer drugs like dronedarone and ranazoline are likely to come into the market in the coming years.

  20. Assessment of inter-atrial, inter-ventricular, and atrio-ventricular interactions in tetralogy of Fallot patients after surgical correction. Insights from two-dimensional speckle tracking and three-dimensional echocardiography.

    Science.gov (United States)

    Abd El Rahman, Mohamed; Raedle-Hurst, Tanja; Rentzsch, Axel; Schäfers, Hans-Joachim; Abdul-Khaliq, Hashim

    2015-10-01

    We aimed to assess biatrial size and function, interactions on atrial and ventricular levels, and atrio-ventricular coupling in patients after tetralogy of Fallot repair. A total of 34 patients with a mean age of 20.9±9 years, and 35 healthy controls, underwent two-dimensional speckle tracking echocardiography for ventricular and atrial strain measurements and real-time three-dimensional echocardiography to assess ventricular and atrial volumes. When compared with controls, tetralogy of Fallot patients had significantly reduced right atrial peak atrial longitudinal strain (ptetralogy of Fallot group, left ventricular ejection fraction was negatively related to the right ventricular end-systolic volume normalised to body surface area (r=-0.62, ptetralogy of Fallot patients, biatrial dysfunction exists and can be quantified via two-dimensional speckle tracking echocardiography as well as real-time three-dimensional echocardiography. Different forms of interactions on atrial and ventricular levels are evident among such cohorts.

  1. Changes in plasma atrial natriuretic factor in patients with idiopathic atrial fibrillation

    International Nuclear Information System (INIS)

    Du Tongxin; Xia Xiaojie; Qu Wei; Wang Shukui; Sun Junjiang

    2002-01-01

    To observe the changes in plasma atrial natriuretic factor (AFN) in patients with idiopathic atrial fibrillation and investigate its mechanism, plasma ANF, platelet count and hematocrit were detected in 21 cases with transient idiopathic atrial fibrillation (group A, A1 representing attack, while A2 termination), 28 with persistent idiopathic atrial fibrillation (group B), 27 suffered from rheumatic heart disease with mitral stenosis and persistent atrial fibrillation (group C), 32 with transient supraventricular tachycardia (group D) and 20 normal controls (group E). It was found that the level of ANF was significantly higher in patients with attacking transient idiopathic atrial fibrillation than that in group A2, D and E (P 0.05), while there was significant difference in hematocrit in group A1 compared with group A2, D, E (P < 0.01). It suggested that ANF and hematocrit play an important role in the attack of idiopathic atrial fibrillation

  2. Echocardiographic reference ranges for normal left atrial function parameters: results from the EACVI NORRE study.

    Science.gov (United States)

    Sugimoto, Tadafumi; Robinet, Sébastien; Dulgheru, Raluca; Bernard, Anne; Ilardi, Federica; Contu, Laura; Addetia, Karima; Caballero, Luis; Kacharava, George; Athanassopoulos, George D; Barone, Daniele; Baroni, Monica; Cardim, Nuno; Hagendorff, Andreas; Hristova, Krasimira; Lopez, Teresa; de la Morena, Gonzalo; Popescu, Bogdan A; Penicka, Martin; Ozyigit, Tolga; Rodrigo Carbonero, Jose David; van de Veire, Nico; Von Bardeleben, Ralph Stephan; Vinereanu, Dragos; Zamorano, Jose Luis; Go, Yun Yun; Marchetta, Stella; Nchimi, Alain; Rosca, Monica; Calin, Andreea; Moonen, Marie; Cimino, Sara; Magne, Julien; Cosyns, Bernard; Galli, Elena; Donal, Erwan; Habib, Gilbert; Esposito, Roberta; Galderisi, Maurizio; Badano, Luigi P; Lang, Roberto M; Lancellotti, Patrizio

    2018-02-23

    To obtain the normal ranges for echocardiographic measurements of left atrial (LA) function from a large group of healthy volunteers accounting for age and gender. A total of 371 (median age 45 years) healthy subjects were enrolled at 22 collaborating institutions collaborating in the Normal Reference Ranges for Echocardiography (NORRE) study of the European Association of Cardiovascular Imaging (EACVI). Left atrial data sets were analysed with a vendor-independent software (VIS) package allowing homogeneous measurements irrespective of the echocardiographic equipment used to acquire data sets. The lowest expected values of LA function were 26.1%, 48.7%, and 41.4% for left atrial strain (LAS), 2D left atrial emptying fraction (LAEF), and 3D LAEF (reservoir function); 7.7%, 24.2%, and -0.53/s for LAS-active, LAEF-active, and LA strain rate during LA contraction (SRa) (pump function) and 12.0% and 21.6% for LAS-passive and LAEF-passive (conduit function). Left atrial reservoir and conduit function were decreased with age while pump function was increased. All indices of reservoir function and all LA strains had no difference in both gender and vendor. However, inter-vendor differences were observed in LA SRa despite the use of VIS. The NORRE study provides contemporary, applicable echocardiographic reference ranges for LA function. Our data highlight the importance of age-specific reference values for LA functions.

  3. Assessment of left atrial volume and function

    DEFF Research Database (Denmark)

    Kühl, J Tobias; Lønborg, Jacob; Fuchs, Andreas

    2012-01-01

    dynamic LA volume changes. Conversely, cardiac magnetic resonance imaging (CMR) and multi-slice computed tomography (MSCT) appears more appropriate for such measures. We sought to determine the relationship between LA size assessed with TTE and LA size and function assessed with CMR and MSCT. Fifty......-four patients were examined 3 months post myocardial infarction with echocardiography, CMR and MSCT. Left atrial volumes and LA reservoir function were assessed by TTE. LA time-volume curves were determined and LA reservoir function (cyclic change and fractional change), passive emptying function (reservoir...... between CMR and MSCT, with a small to moderate bias in LA(max) (4.9 ± 10.4 ml), CC (3.1 ± 9.1 ml) and reservoir volume (3.4 ± 9.1 ml). TTE underestimates LA(max) with up to 32% compared with CMR and MSCT (P ...

  4. [Typical atrial flutter: Diagnosis and therapy].

    Science.gov (United States)

    Thomas, Dierk; Eckardt, Lars; Estner, Heidi L; Kuniss, Malte; Meyer, Christian; Neuberger, Hans-Ruprecht; Sommer, Philipp; Steven, Daniel; Voss, Frederik; Bonnemeier, Hendrik

    2016-03-01

    Typical, cavotricuspid-dependent atrial flutter is the most common atrial macroreentry tachycardia. The incidence of atrial flutter (typical and atypical forms) is age-dependent with 5/100,000 in patients less than 50 years and approximately 600/100,000 in subjects > 80 years of age. Concomitant heart failure or pulmonary disease further increases the risk of typical atrial flutter.Patients with atrial flutter may present with symptoms of palpitations, reduced exercise capacity, chest pain, or dyspnea. The risk of thromboembolism is probably similar to atrial fibrillation; therefore, the same antithrombotic prophylaxis is required in atrial flutter patients. Acutely symptomatic cases may be subjected to cardioversion or pharmacologic rate control to relieve symptoms. Catheter ablation of the cavotricuspid isthmus represents the primary choice in long-term therapy, associated with high procedural success (> 97 %) and low complication rates (0.5 %).This article represents the third part of a manuscript series designed to improve professional education in the field of cardiac electrophysiology. Mechanistic and clinical characteristics as well as management of isthmus-dependent atrial flutter are described in detail. Electrophysiological findings and catheter ablation of the arrhythmia are highlighted.

  5. Atrial natriuretic peptide (ANP)-granules: ultrastructure ...

    African Journals Online (AJOL)

    ANP) are present in the four regions of the atrial-auricular complex (two atria and two auricles). ANP-immunoreactivity was detected in all granules from the four regions. Ultrastructurally, atrial myocytes show the presence of very electron dense ...

  6. Radiofrequency catheter oblation in atrial flutter

    International Nuclear Information System (INIS)

    Yan Ji; Wang Heping; Xu Jian; Liu Fuyuan; Fan Xizhen; An Chunsheng; Han Xiaoping; Ding Xiaomei; Wang Jiasheng; Gu Tongyuan

    2002-01-01

    Objective: To evaluate the radiofrequency catheter ablation for type I atrial flutter through application of Holo catheter labelling with anatomic imaging localization to ablate the isthmus of IVCTA during complete double-way block. Methods: Eleven cases with type I atrial flutter undergone Holo catheter labelling technique and consecution with conduction time change of coronary venous sinus orifice with-right atrial lower lateral wall pace excitation, were performed with radiofrequency catheter ablation for the isthmus outcoming with complete double-way conduction block. Results: All together 11 cases with 4 of atrial flutter and 7 of sinus rhythm were undergone radiofrequency catheter ablation resulting with double-way conduction block of the isthmus accompanied by prolongation of right atrial conduction time 56.0 ± 2.3 ms and 53.0 ± 4.6 ms respectively. The right atrial excitation appeared to be in clockwise and counter-clockwise of single direction. No recurrence occurred during 3-34 months follow up with only one showing atrial fibrillation. Conclusions: The application of Holo catheter labelling technique with anatomic imaging localization to achieve the double-way conduction block by radiofrequency catheter ablation of TVC-TA isthmus, is a reliable method for treating atrial flutter

  7. Left atrial dysfunction in patients with patent foramen ovale and atrial septal aneurysm: an alternative concurrent mechanism for arterial embolism?

    Science.gov (United States)

    Rigatelli, Gianluca; Aggio, Silvio; Cardaioli, Paolo; Braggion, Gabriele; Giordan, Massimo; Dell'avvocata, Fabio; Chinaglia, Mauro; Rigatelli, Giorgio; Roncon, Loris; Chen, Jack P

    2009-07-01

    We postulate that, in patients with large patent foramen ovales (PFO) and atrial septal aneurysms (ASA), left atrial (LA) dysfunction simulating "atrial fibrillation (AF)-like" pathophysiology might represent an alternate mechanism in the promotion of arterial embolism. Despite prior reports concerning paradoxical embolism through a PFO, the magnitude of this phenomenon as a risk factor for stroke remains undefined, because deep venous thrombosis is infrequently detected in such patients. To test our hypothesis, we prospectively enrolled 98 consecutive patients with previous stroke (mean age 37 +/- 12.5 years, 58 women) referred to our center for catheter-based PFO closure. Baseline values of LA passive and active emptying, LA conduit function, LA ejection fraction, and spontaneous echocontrast (SEC) in the LA and LA appendage were compared with those of 50 AF patients as well as a sex/age/cardiac risk-matched population of 70 healthy control subjects. Pre-closure PFO subjects demonstrated significantly greater reservoir function as well as passive and active emptying, with significantly reduced conduit function and LA ejection fraction, when compared with AF and control patients. Furthermore, in PFO patients, 66.3% (65 of 98) had moderate-to-severe ASA and basal shunt; SEC was observed in 52% of PFO plus ASA patients before closure. Multivariate stepwise logistic regression revealed moderate-to-severe ASA (odds ratio: 9.4, 95% confidence interval: 7.0 to 23.2, p < 0.001) as the most powerful predictor of LA dysfunction. After closure, all LA parameters normalized to the levels of control subjects: no SEC, device-related thrombosis, or aortic erosion were observed on follow-up echocardiography. This study suggests that moderate-to-severe ASA might be associated with LA dysfunction in patients with PFO. The resultant similarities to the pathophysiology of AF might represent an additional contributing mechanism for arterial embolism in such patients.

  8. Reliability Of A Novel Intracardiac Electrogram Method For AV And VV Delay Optimization And Comparability To Echocardiography Procedure For Determining Optimal Conduction Delays In CRT Patients

    Directory of Open Access Journals (Sweden)

    N Reinsch

    2009-03-01

    Full Text Available Background: Echocardiography is widely used to optimize CRT programming. A novel intracardiac electrogram method (IEGM was recently developed as an automated programmer-based method, designed to calculate optimal atrioventricular (AV and interventricular (VV delays and provide optimized delay values as an alternative to standard echocardiographic assessment.Objective: This study was aimed at determining the reliability of this new method. Furthermore the comparability of IEGM to existing echocardiographic parameters for determining optimal conduction delays was verified.Methods: Eleven patients (age 62.9± 8.7; 81% male; 73% ischemic, previously implanted with a cardiac resynchronisation therapy defibrillator (CRT-D underwent both echocardiographic and IEGM-based delay optimization.Results: Applying the IEGM method, concordance of three consecutively performed measurements was found in 3 (27% patients for AV delay and in 5 (45% patients for VV delay. Intra-individual variation between three measurements as assessed by the IEGM technique was up to 20 ms (AV: n=6; VV: n=4. E-wave, diastolic filling time and septal-to-lateral wall motion delay emerged as significantly different between the echo and IEGM optimization techniques (p < 0.05. The final AV delay setting was significantly different between both methods (echo: 126.4 ± 29.4 ms, IEGM: 183.6 ± 16.3 ms; p < 0.001; correlation: R = 0.573, p = 0.066. VV delay showed significant differences for optimized delays (echo: 46.4 ± 23.8 ms, IEGM: 10.9 ± 7.0 ms; p <0.01; correlation: R = -0.278, p = 0.407.Conclusion: The automated programmer-based IEGM-based method provides a simple and safe method to perform CRT optimization. However, the reliability of this method appears to be limited. Thus, it remains difficult for the examiner to determine the optimal hemodynamic settings. Additionally, as there was no correlation between the optimal AV- and VV-delays calculated by the IEGM method and the echo

  9. Left atrial ejection force predicts the outcome after catheter ablation for paroxysmal atrial fibrillation.

    Science.gov (United States)

    Kishima, Hideyuki; Mine, Takanao; Takahashi, Satoshi; Ashida, Kenki; Ishihara, Masaharu; Masuyama, Tohru

    2018-02-01

    Left atrium (LA) systolic dysfunction is observed in the early stages of atrial fibrillation (AF) prior to LA anatomical change. We investigated whether LA systolic dysfunction predicts recurrent AF after catheter ablation (CA) in patients with paroxysmal AF. We studied 106 patients who underwent CA for paroxysmal AF. LA systolic function was assessed with the LA emptying volume = Maximum LA volume (LAV max ) - Minimum LA volume (LAV min ), LA emptying fraction = [(LAV max - LAV min )/LAV max ] × 100, and LA ejection force calculated with Manning's method [LA ejection force = (0.5 × ρ × mitral valve area × A 2 )], where ρ is the blood density and A is the late-diastolic mitral inflow velocity. Recurrent AF was detected in 35/106 (33%) during 14.6 ± 9.1 months. Univariate analysis revealed reduced LA ejection force, decreased LA emptying fraction, larger LA diameter, and elevated brain natriuretic peptide as significant variables. On multivariate analysis, reduced LA ejection force and larger LA diameter were independently associated with recurrent AF. Moreover, patients with reduced LA ejection force and larger LA diameter had a higher risk of recurrent AF than preserved LA ejection force (log-rank P = 0.0004). Reduced LA ejection force and larger LA diameter were associated with poor outcome after CA for paroxysmal AF, and could be a new index to predict recurrent AF. © 2017 Wiley Periodicals, Inc.

  10. Artificial atrial fibrillation in the dog. An artifact?

    NARCIS (Netherlands)

    Strackee, J.; Hoelen, A.J.; Zimmerman, A.N.E.; Meijler, F.L.

    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

  11. Rationale and Design of the Reduce Elevated Left Atrial Pressure in Patients With Heart Failure (Reduce LAP-HF) Trial

    DEFF Research Database (Denmark)

    Hasenfuss, Gerd; Gustafsson, Finn; Kaye, David

    2015-01-01

    OBJECTIVE: Heart failure with preserved ejection fraction (HFpEF) is characterized by elevated left atrial pressure during rest and/or exercise. The Reduce LAP-HF (Reduce Elevated Left Atrial Pressure in Patients With Heart Failure) trial will evaluate the safety and performance of the Interatrial...... Shunt Device (IASD) System II, designed to directly reduce elevated left atrial pressure, in patients with HFpEF. METHODS: The Reduce LAP-HF Trial is a prospective, nonrandomized, open-label trial to evaluate a novel device that creates a small permanent shunt at the level of the atria. A minimum of 60...... patients with ejection fraction ≥40% and New York Heart Association functional class III or IV heart failure with a pulmonary capillary wedge pressure (PCWP) ≥15 mm Hg at rest or ≥25 mm Hg during supine bike exercise will be implanted with an IASD System II, and followed for 6 months to assess the primary...

  12. Left Atrial 4D Blood Flow Dynamics and Hemostasis following Electrical Cardioversion of Atrial Fibrillation

    Directory of Open Access Journals (Sweden)

    Merih Cibis

    2017-12-01

    Full Text Available Background: Electrical cardioversion in patients with atrial fibrillation is followed by a transiently impaired atrial mechanical function, termed atrial stunning. During atrial stunning, a retained risk of left atrial thrombus formation exists, which may be attributed to abnormal left atrial blood flow patterns. 4D Flow cardiovascular magnetic resonance (CMR enables blood flow assessment from the entire three-dimensional atrial volume throughout the cardiac cycle. We sought to investigate left atrial 4D blood flow patterns and hemostasis during left atrial stunning and after left atrial mechanical function was restored.Methods: 4D Flow and morphological CMR data as well as blood samples were collected in fourteen patients at two time-points: 2–3 h (Time-1 and 4 weeks (Time-2 following cardioversion. The volume of blood stasis and duration of blood stasis were calculated. In addition, hemostasis markers were analyzed.Results: From Time-1 to Time-2: Heart rate decreased (61 ± 7 vs. 56 ± 8 bpm, p = 0.01; Maximum change in left atrial volume increased (8 ± 4 vs. 22 ± 15%, p = 0.009; The duration of stasis (68 ± 11 vs. 57 ± 8%, p = 0.002 and the volume of stasis (14 ± 9 vs. 9 ± 7%, p = 0.04 decreased; Thrombin-antithrombin complex (TAT decreased (5.2 ± 3.3 vs. 3.3 ± 2.2 μg/L, p = 0.008. A significant correlation was found between TAT and the volume of stasis (r2 = 0.69, p < 0.001 at Time-1 and between TAT and the duration of stasis (r2 = 0.34, p = 0.04 at Time-2.Conclusion: In this longitudinal study, left atrial multidimensional blood flow was altered and blood stasis was elevated during left atrial stunning compared to the restored left atrial mechanical function. The coagulability of blood was also elevated during atrial stunning. The association between blood stasis and hypercoagulability proposes that assessment of left atrial 4D flow can add to the pathophysiological understanding of thrombus formation during atrial fibrillation

  13. Left Atrial 4D Blood Flow Dynamics and Hemostasis following Electrical Cardioversion of Atrial Fibrillation

    Science.gov (United States)

    Cibis, Merih; Lindahl, Tomas L.; Ebbers, Tino; Karlsson, Lars O.; Carlhäll, Carl-Johan

    2017-01-01

    Background: Electrical cardioversion in patients with atrial fibrillation is followed by a transiently impaired atrial mechanical function, termed atrial stunning. During atrial stunning, a retained risk of left atrial thrombus formation exists, which may be attributed to abnormal left atrial blood flow patterns. 4D Flow cardiovascular magnetic resonance (CMR) enables blood flow assessment from the entire three-dimensional atrial volume throughout the cardiac cycle. We sought to investigate left atrial 4D blood flow patterns and hemostasis during left atrial stunning and after left atrial mechanical function was restored. Methods: 4D Flow and morphological CMR data as well as blood samples were collected in fourteen patients at two time-points: 2–3 h (Time-1) and 4 weeks (Time-2) following cardioversion. The volume of blood stasis and duration of blood stasis were calculated. In addition, hemostasis markers were analyzed. Results: From Time-1 to Time-2: Heart rate decreased (61 ± 7 vs. 56 ± 8 bpm, p = 0.01); Maximum change in left atrial volume increased (8 ± 4 vs. 22 ± 15%, p = 0.009); The duration of stasis (68 ± 11 vs. 57 ± 8%, p = 0.002) and the volume of stasis (14 ± 9 vs. 9 ± 7%, p = 0.04) decreased; Thrombin-antithrombin complex (TAT) decreased (5.2 ± 3.3 vs. 3.3 ± 2.2 μg/L, p = 0.008). A significant correlation was found between TAT and the volume of stasis (r2 = 0.69, p < 0.001) at Time-1 and between TAT and the duration of stasis (r2 = 0.34, p = 0.04) at Time-2. Conclusion: In this longitudinal study, left atrial multidimensional blood flow was altered and blood stasis was elevated during left atrial stunning compared to the restored left atrial mechanical function. The coagulability of blood was also elevated during atrial stunning. The association between blood stasis and hypercoagulability proposes that assessment of left atrial 4D flow can add to the pathophysiological understanding of thrombus formation during atrial fibrillation related

  14. Fractional charges

    International Nuclear Information System (INIS)

    Saminadayar, L.

    2001-01-01

    20 years ago fractional charges were imagined to explain values of conductivity in some materials. Recent experiments have proved the existence of charges whose value is the third of the electron charge. This article presents the experimental facts that have led theorists to predict the existence of fractional charges from the motion of quasi-particles in a linear chain of poly-acetylene to the quantum Hall effect. According to the latest theories, fractional charges are neither bosons nor fermions but anyons, they are submitted to an exclusive principle that is less stringent than that for fermions. (A.C.)

  15. Isthmus Dependent Atrial Flutter Cycle Length Correlates with Right Atrial Cross-Sectional Area

    Directory of Open Access Journals (Sweden)

    Kousik Krishnan

    2009-05-01

    Full Text Available Background: Right atrial flutter cycle length can prolong in the presence of antiarrhythmic drug therapy. We hypothesized that the cycle length of right atrial isthmus dependent flutter would correlate with right atrial cross-sectional area measurements. Methods: 60 patients who underwent ablation for electrophysiologically proven isthmus dependent right atrial flutter, who were not on Class I or Class III antiarrhythmic drugs and had recent 2-dimensional echocardiographic data comprised the study group. Right atrial length and width were measured in the apical four chamber view. Cross-sectional area was estimated by multiplying the length and width. 35 patients had an atrial flutter rate ≥250 bpm (Normal Flutter Group and 25 patients had an atrial flutter rate < 250 bpm (Slow Flutter Group. Results: Mean atrial flutter rate was 283 bpm in the normal flutter group and 227 bpm in the slow flutter group. Mean atrial flutter cycle length was 213 ms in the Normal Flutter Group and 265 ms in the Slow Flutter Group (p<0.0001. Mean right atrial cross sectional area was 1845 mm2 in the Normal Flutter group and 2378 mm2 in the Slow Flutter Group, (p< 0.0001. Using linear regression, CSA was a significant predictor of cycle length (β =0.014 p = 0.0045. For every 1 mm2 increase in cross-sectional area, cycle length is 0.014 ms longer.Conclusion: In the absence of antiarrhythmic medications, right atrial cross sectional area enlargement correlates with atrial flutter cycle length. These findings provide further evidence that historical rate-related definitions of typical isthmus dependent right atrial are not mechanistically valid.

  16. [Left versus bi-atrial radiofrequency ablation in the treatment of atrial fibrillation].

    Science.gov (United States)

    Wang, Jian-Gang; Meng, Xu; Li, Hui

    2008-11-25

    To evaluate the effectiveness of radiofrequency modified maze operation for the treatment of atrial fibrillation (AF) and compare the results of the left versus bi-atrial procedures. 305 patients of organic heart disease combined with AF, 117 males and 188 females, aged (53 +/- 10), that underwent cardiac valve operation (n = 293) and/or coronary artery bypass graft surgery (n = 14), received concomitant atrial fibrillation, bi-atrial (n = 160) or left atrial (n = 145) with a mean duration of (36 +/- 43) months. Follow-up was conducted for (28 +/- 5) (3 - 42) months. Thirteen patients (4.3%) died postoperatively: 7 died of multisystem and organ failure, 3 of low cardiac output, 1 of rupture of left ventricle, 1 of arrhythmia, and 1 of sudden death. During the follow-up, 1 patient died of heart failure, 1 of encephalorrhagia and 1 of unknown reason in the bi-atrial group. At the end of the procedure 223 patients (73.1%) had sinus rhythm, with a sinus rhythm rate of 66.9% (107/160) in the bi-atrial group, significant lower than that in the left atrial group (80.0%, 116/145, P bi-atrial group was 80.0%, not significantly different from that of the left atrial group (81.9%, P > 0.05). The Kaplan-Meier survival analysis showed there was no significant difference in the AF rhythm rate between these 2 groups (P = 0.33). Logistic regression analysis showed that the left atrial diameter of >/= 80 mm was an independent predictor of AF recurrence. Both the left and bi-atrial procedures are successful in terms of restoring sinus rhythm. Left atrial ablation in severe cases and where the incision of right atrium is not needed is a reasonable choice.

  17. Cetirizine-Induced atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Altuğ Osken

    2016-01-01

    Full Text Available Atrial fibrillation (AF is the most common observed arrhythmia in clinical practice. In the literature, AF events associated with drug induction are available. Cetirizine is a second-generation histamine antagonist used in the treatment of allergies, angioedema, and urticaria. We wish to present an atypical case who took cetirizine medication for relieving symptoms of upper tract respiratory system infection, experienced rapid ventricular response AF and treated successfully. To best of our knowledge, this is the first case of cetirizine-induced AF.

  18. Fractional fermions

    International Nuclear Information System (INIS)

    Jackiw, R.; Massachusetts Inst. of Tech., Cambridge; Massachusetts Inst. of Tech., Cambridge

    1984-01-01

    The theory of fermion fractionization due to topologically generated fermion ground states is presented. Applications to one-dimensional conductors, to the MIT bag, and to the Hall effect are reviewed. (author)

  19. The effect of surgical treatment for secundum atrial septal defect in patients more than 30 years old.

    Science.gov (United States)

    Erkut, Bilgehan; Becit, Necip; Unlu, Yahya; Ceviz, Munacettin; Kocogullari, Cevdet Ugur; Ates, Azman; Karapolat, Bekir Sami; Kaygin, Mehmet Ali; Kocak, Hikmet

    2007-01-01

    We prospectively examined whether surgical treatment of secundum atrial septal defects in patients 30 years old improves their early- and mid-term clinical outcomes. Our clinical experience is reviewed to assess the importance of surgical management in elderly patients with atrial septal defect. We analyzed 41 patients older than 30 years of age who underwent surgical correction of a secundum atrial septal defect. To evaluate the effects of surgical treatment, we compared functional capacity, diuretic administration, rhythm status, and echocardiographic parameters of all patients before and after the operation. The median follow-up period was 4.2 years (range, 6 months-7 years). There were no operative deaths. Functional class in most of the patients improved after operation. Two patients reverted to normal sinus rhythm after the operation. There was only one new atrial fibrilation among patients in the postoperative term. Right atrial and right ventricular dimensions and pulmonary artery pressures were significantly decreased, and ejection fractions were significantly increased after the operation. The need for diuretic treatment was decreased after surgical repair. No residual intracardiac shunts were identified during follow-up. There were no cerebrovascular thromboembolic accidents in the early postoperative period. Surgical closure of atrial septal defects in patients over 30 years old can improve their clinical status and prevent right ventricular dilatation and insufficiency. The operation must be performed as soon as possible, even if the symptoms or the hemodynamic impact seem to be minimal.

  20. Beat-to-beat left ventricular performance in atrial fibrillation: radionuclide assessment with the computerized nuclear probe

    International Nuclear Information System (INIS)

    Schneider, J.; Berger, H.J.; Sands, M.J.; Lachman, A.B.; Zaret, B.L.

    1983-01-01

    There is wide beat-to-beat variability in cycle length and left ventricular performance in patients with atrial fibrillation. In this study, left ventricular ejection fraction and relative left ventricular volumes were evaluated on a beat-to-beat basis with the computerized nuclear probe, an instrument with sufficiently high sensitivity to allow continuous evaluation of the radionuclide time-activity curve. Of 18 patients with atrial fibrillation, 5 had mitral stenosis, 6 had mitral regurgitation, and 7 had coronary artery disease. Fifty consecutive beats were analyzed in each patient. The mean left ventricular ejection fraction ranged from 17 to 51%. There was substantial beat-to-beat variation in cycle length and left ventricular ejection fraction in all patients, including those with marked left ventricular dysfunction. In 14 patients who also underwent multiple gated cardiac blood pool imaging, there was an excellent correlation between mean ejection fraction derived from the nuclear probe and gated ejection fraction obtained by gamma camera imaging (r . 0.90). Based on beat-to-beat analysis, left ventricular function was dependent on relative end-diastolic volume and multiple preceding cycle lengths, but not preceding end-systolic volumes. This study demonstrates that a single value for left ventricular ejection fraction does not adequately characterize left ventricular function in patients with atrial fibrillation. Furthermore, both the mean beat-to-beat and the gated ejection fraction may underestimate left ventricular performance at rest in such patients

  1. 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.

  2. Left Ventricular Systolic Function Assessed by Global Longitudinal Strain is Impaired in Atrial Fibrillation Compared to Sinus Rhythm

    DEFF Research Database (Denmark)

    Agner, Bue Fridolin Ross; Katz, Michael G; Williams, Zachary R

    2018-01-01

    Background: Atrial fibrillation (AF) is the most common aberrant cardiac arrhythmia. Many AF patients present with symptoms of dyspnea and fatigue, but have normal left ventricular ejection fraction (LVEF). Purpose: To determine the reproducibility of measurements of global longitudinal strain (GLS...

  3. 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...

  4. Detection and evaluation of left atrial myxoma by gated radionuclide imaging

    International Nuclear Information System (INIS)

    Sugihara, Hiroki; Adachi, Haruhiko; Nakagawa, Hiroaki

    1985-01-01

    Radionuclide imaging plays an important role in diagnosising left atrial myxoma (LAM). We discussed diagnostic value of Fourier analysis with phase image and evaluated left ventricular filling function using indices such as 1/3 Filling Fraction, Rapid Filling Fraction and Peak Filling Rate derived from left ventricular volume curve. Equillibrium radionuclide angiocardiography was performed in 6 LAM patients. Phase delay in the basal portion of the left ventricle was shown in 5 of 6 LAM patients, and standard deviation of left ventricular phase was larger than these of controls. Left ventricular filling disturbance was suggested in 5 of 6 LAM patients. After surgical remove of myxoma phase delay was disappeared and standard deviation was normalized. And left ventricular filling was improved. We concluded that the phase image of Fourier analysis revealed a left atrial mass prolapsing in the left ventricule during the diastole, and that diastolic indices were useful for left ventricular filling disturbance due to LAM. (author)

  5. 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 congenital 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.

  6. 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

  7. Assessment of left atrial volume and function: a comparative study between echocardiography, magnetic resonance imaging and multi slice computed tomography.

    Science.gov (United States)

    Kühl, J Tobias; Lønborg, Jacob; Fuchs, Andreas; Andersen, Mads J; Vejlstrup, Niels; Kelbæk, Henning; Engstrøm, Thomas; Møller, Jacob E; Kofoed, Klaus F

    2012-06-01

    Measurement of left atrial (LA) maximal volume (LA(max)) using two-dimensional transthoracic echocardiography (TTE) provides prognostic information in several cardiac diseases. However, the relationship between LA(max) and LA function is poorly understood and TTE is less well suited for measuring dynamic LA volume changes. Conversely, cardiac magnetic resonance imaging (CMR) and multi-slice computed tomography (MSCT) appears more appropriate for such measures. We sought to determine the relationship between LA size assessed with TTE and LA size and function assessed with CMR and MSCT. Fifty-four patients were examined 3 months post myocardial infarction with echocardiography, CMR and MSCT. Left atrial volumes and LA reservoir function were assessed by TTE. LA time-volume curves were determined and LA reservoir function (cyclic change and fractional change), passive emptying function (reservoir volume) and pump function (left atrial ejection fraction-LAEF) were derived using CMR and MSCT. Left atrial fractional change and left atrial ejection fraction (LAEF) determined with CMR and MSCT were unrelated to LA(max) enlargement by echocardiography (P = NS). There was an overall good agreement between CMR and MSCT, with a small to moderate bias in LA(max) (4.9 ± 10.4 ml), CC (3.1 ± 9.1 ml) and reservoir volume (3.4 ± 9.1 ml). TTE underestimates LA(max) with up to 32% compared with CMR and MSCT (P fractional change and LAEF is not significantly related to LA(max) measured by TTE. TTE systematically underestimated LA volumes, whereas there are good agreements between MSCT and CMR for volumetric and functional properties.

  8. 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.

  9. Assessment of right atrial function analysis

    International Nuclear Information System (INIS)

    Shohgase, Takashi; Miyamoto, Atsushi; Kanamori, Katsushi; Kobayashi, Takeshi; Yasuda, Hisakazu

    1988-01-01

    To assess the potential utility of right atrial function analysis in cardiac disease, reservoir function, pump function, and right atrial peak emptying rate (RAPER) were compared in 10 normal subjects, 32 patients with coronary artery disease, and 4 patients with primary pulmonary hypertension. Right atrial volume curves were obtained using cardiac radionuclide method with Kr-81m. In normal subjects, reservoir function index was 0.41+-0.05; pump function index was 0.25+-0.05. Both types of patients has decreased reservoir funcion and increased pump function. Pump function tended to decrease with an increase of right ventricular end-diastolic pressure. RAPER correlated well with right ventricular peak filling rate, probably reflecting right ventricular diastolic function. Analysis of right atrial function seemed to be of value in evaluating factors regulating right ventricular contraction and diastolic function, and cardiac output. (Namekawa, K)

  10. Atrial natriuretic peptide (ANP)-granules: ultrastructure ...

    African Journals Online (AJOL)

    AJB SERVER

    2006-12-29

    Dec 29, 2006 ... morphometry and function. Eliane Florencio ... granules is greatest in the right atrium followed by the left atrium and left auricle and right auricle, in this order. ... family: Atrial natriuretic peptide (ANP), Urodilatin, Brain natriuretic ...

  11. Mystery Fractions

    Science.gov (United States)

    Bhattacharyya, Sonalee; Namakshi, Nama; Zunker, Christina; Warshauer, Hiroko K.; Warshauer, Max

    2016-01-01

    Making math more engaging for students is a challenge that every teacher faces on a daily basis. These authors write that they are constantly searching for rich problem-solving tasks that cover the necessary content, develop critical-thinking skills, and engage student interest. The Mystery Fraction activity provided here focuses on a key number…

  12. Vdrive Evaluation of Remote Steering and Testing in Lasso Electrophysiology Procedures Study: The VERSATILE Study in Atrial Fibrillation Ablation.

    Science.gov (United States)

    Nölker, Georg; Schwagten, Bruno; Deville, J Brian; Burkhardt, J David; Horton, Rodney P; Sha, Qun; Tomassoni, Gery

    2016-03-01

    Circular mapping catheters (CMC) are an essential tool in most atrial fibrillation ablation procedures. The Vdrive™ with V-Loop™ system enables a physician to remotely manipulate a CMC during electrophysiology studies. Our aim was to compare the clinical performance of the system to conventional CMC navigation according to efficiency and safety endpoints. A total of 120 patients scheduled to undergo a CMC study followed by pulmonary vein isolation (PVI) were included. Treatment allocation was randomized 2:1, remote navigation:manual navigation. The primary effectiveness endpoint was assessed based on both successful navigation to the targeted pulmonary vein (PV) and successful recording of PV electrograms. All PVs were treated independently within and between patients. The primary safety endpoint was assessed based on the occurrence of major adverse events (MAEs) through seven days after the study procedure. Primary effectiveness endpoints were achieved in 295/302 PVs in the Vdrive arm (97.7%) and 167/167 PVs in the manual arm (100%). Effectiveness analysis indicates Vdrive non-inferiority (pnon-inferiority = 0.0405; δ = -0.05) per the Cochran-Mantel-Haenszel test adjusted for PV correlation. Five MAEs related to the ablation procedure occurred (three in the Vdrive arm-3.9%; two in the manual arm-2.33%). No device-related MAEs were observed; safety analysis indicates Vdrive non-inferiority (pnon-inferiority = 0.0441; δ = 0.07) per the normal Z test. Remote navigation of a CMC is equivalent to manual in PVI in terms of safety and effectiveness. This allows for single-operator procedures in conjunction with a magnetically guided ablation catheter. © 2016 Wiley Periodicals, Inc.

  13. Psychosomatic correlations in atrial fibrillations

    Directory of Open Access Journals (Sweden)

    Vladimir Ernstovich Medvedev

    2011-01-01

    Full Text Available Patients with atrial fibrillations (AF and comorbid mental disorders were examined. Two patient groups differing in the structure of psychosomatic ratios were identified. Group 1 comprised patients with AF and signs of reactivity lability that manifested itself as psychopathological reactions to the primary manifestations of AF; Group 2 included those who had developed mental disorders mainly in end-stage cardiovascular disease (predominantly a permanent form of AF in the presence of such events as chronic heart failure (CHF. The results of the study suggest that the patients with AF have frequently anxiety and hypochondriacal disorders, which agrees with the data available in the literature. In addition, end-stage AF is marked by depressive syndromes caused by the severe course of cardiovascular diseases resulting in CHF.

  14. RR-Interval variance of electrocardiogram for atrial fibrillation detection

    Science.gov (United States)

    Nuryani, N.; Solikhah, M.; Nugoho, A. S.; Afdala, A.; Anzihory, E.

    2016-11-01

    Atrial fibrillation is a serious heart problem originated from the upper chamber of the heart. The common indication of atrial fibrillation is irregularity of R peak-to-R-peak time interval, which is shortly called RR interval. The irregularity could be represented using variance or spread of RR interval. This article presents a system to detect atrial fibrillation using variances. Using clinical data of patients with atrial fibrillation attack, it is shown that the variance of electrocardiographic RR interval are higher during atrial fibrillation, compared to the normal one. Utilizing a simple detection technique and variances of RR intervals, we find a good performance of atrial fibrillation detection.

  15. Atorvastatin can ameliorate left atrial stunning induced by radiofrequency ablation for atrial fibrillation.

    Science.gov (United States)

    Xie, Ruiqin; Yang, Yingtao; Cui, Wei; Yin, Hongning; Zheng, Hongmei; Zhang, Jidong; You, Ling

    2017-09-01

    The objective of this study was to study the functional changes of the left atrium after radiofrequency ablation treatment for atrial fibrillation and the therapeutic effect of atorvastatin. Fifty-eight patients undergoing radiofrequency ablation for atrial fibrillation were randomly divided into non-atorvastatin group and atorvastatin group. Patients in the atorvastatin group were treated with atorvastatin 20 mg p.o. per night in addition to the conventional treatment of atrial fibrillation; patients in the non-atorvastatin group received conventional treatment of atrial fibrillation only. Echocardiography was performed before radiofrequency ablation operation and 1 week, 2 weeks, 3 weeks, and 4 weeks after operation. Two-dimensional ultrasound speckle tracking imaging system was used to measure the structural indexes of the left atrium. Results indicated that there was no significant change for indexes representing the structural status of the left atrium within a month after radiofrequency ablation (P > 0.05); however, there were significant changes for indexes representing the functional status of the left atrium. There were also significant changes in indexes reflecting left atrial strain status: the S and SRs of atorvastatin group were higher than those of non-atorvastatin group (P atorvastatin could improve left atrial function and shorten the duration of atrial stunning after radiofrequency ablation of atrial fibrillation.

  16. Prednisone prevents atrial fibrillation promotion by atrial tachycardia remodeling in dogs

    NARCIS (Netherlands)

    Shiroshita-Takeshita, A; Brundel, BJJM; Lavoie, J; Nattel, S

    2006-01-01

    Background: There is evidence suggesting involvement of oxidative stress, inflammation, and calcineurin/nuclear factor of activated T cell pathways in atrial fibrillation. This study evaluated the efficacy of anti-inflammatory and calcineurin-inhibitory drugs on promotion of atrial fibrillation by

  17. Incisional left atrial isolation for ablation of atrial fibrillation in mitral valve surgery.

    Science.gov (United States)

    Graffigna, Angelo; Branzoli, Stefano; Sinelli, Stefano; Vigano, Mario

    2009-01-01

    The renewed interest in surgical techniques for atrial fibrillation (AF) limited to the left atrium has risen the importance of the original technique of left atrial isolation by means of surgical incision. Transmurality of lesions and cost containment are strong elements to be appreciated in this technique.

  18. Study on the changes of serum levels of ANF in patients with atrial fibrillation (AF)

    International Nuclear Information System (INIS)

    Xia Xiaojie; Zan Qin; Yang Junfeng; Huang Yuantao; Cao Kejiang; Du Tongxing; Wang Zizheng

    2004-01-01

    Objective: To study the changes of serum levels of ANF in patients with atrial fibrillation and to explore the mechanism of the prethrombotic state induced by AF. Methods: Serum levels of ANF were measured with RIA in 21 patients with isolated paroxysmal atrial fibrillation (IPAF) both during and one week after termination of the attack. Levels were also measured in 28 patients with isolated sustained atrial fibrillation (ISAF), 27 patients with rheumatic mitral stenosis associated with persistent AF (RHD), 32 patients with paroxysmal supraventricular tachycardia (PSVT) and 35 controls. Results: Serum levels of ANF and Hct% readings in: 1) patients with IPAF during attack 2) patients with ISAF and 3) patients with RHD were significantly higher than those in: 1) patients with IPAF one week after termination of the attack 2) patients with PSVT and 3) the controls (p<0.05). Values in patients with PSVT were not much different from those in controls. In patients with IPAF during the attack, serum ANF levels and Hct% readings were positively correlated to the duration of the attack. Serum ANF levels were not related to such parameters as: age, sex, mitral valve area, ejection fraction and inner diameter of left atrium. Conclusion: There is hemoconcentration in patients with atrial fibrillation, which is related to the hypersecretion of ANF in these patients

  19. Fraction Reduction through Continued Fractions

    Science.gov (United States)

    Carley, Holly

    2011-01-01

    This article presents a method of reducing fractions without factoring. The ideas presented may be useful as a project for motivated students in an undergraduate number theory course. The discussion is related to the Euclidean Algorithm and its variations may lead to projects or early examples involving efficiency of an algorithm.

  20. Effect of age on stroke prevention therapy in patients with atrial fibrillation: the atrial fibrillation investigators

    DEFF Research Database (Denmark)

    van Walraven, Carl; Hart, Robert G; Connolly, Stuart

    2009-01-01

    contains patient level-data from randomized trials of stroke prevention in atrial fibrillation. We used Cox regression models with age as a continuous variable that controlled for sex, year of randomization, and history of cerebrovascular disease, diabetes, hypertension, and congestive heart failure......BACKGROUND AND PURPOSE: Stroke risk increases with age in patients who have nonvalvular atrial fibrillation. It is uncertain whether the efficacy of stroke prevention therapies in atrial fibrillation changes as patients age. The objective of this study was to determine the effect of age...... on the relative efficacy of oral anticoagulants (OAC) and antiplatelet (AP) therapy (including acetylsalicylic acid and triflusal) on ischemic stroke, serious bleeding, and vascular events in patients with atrial fibrillation. METHODS: This is an analysis of the Atrial Fibrillation Investigators database, which...

  1. Atrial Na,K-ATPase increase and potassium dysregulation accentuate the risk of postoperative atrial fibrillation

    DEFF Research Database (Denmark)

    Tran, Cao Thach; Schmidt, Thomas Andersen; Christensen, John Brochorst

    2009-01-01

    BACKGROUND: Postoperative atrial fibrillation is a common complication to cardiac surgery. Na,K-ATPase is of major importance for the resting membrane potential and action potential. The purpose of the present study was to evaluate the importance of Na,K-ATPase concentrations in human atrial...... biopsies and plasma potassium concentrations for the development of atrial fibrillation. METHODS: Atrial myocardial biopsies were obtained from 67 patients undergoing open chest cardiac surgery. Na,K-ATPase was quantified using vanadate-facilitated 3H-ouabain binding. Plasma potassium concentration....../g wet weight (n = 33), p = 0.03]. Also with multivariable analysis, 3H-ouabain-binding site concentration was significantly associated with the development of atrial fibrillation. High increase in plasma potassium concentration during the perioperative period and surgery was associated...

  2. LEFT ATRIAL FIBROSIS IN PATIENTS WITH ATRIAL FIBRILLATION ACCORDING TO MAGNETIC RESONANCE IMAGING WITH LATE GADOLINIUM ENHANCEMENT

    Directory of Open Access Journals (Sweden)

    O. V. Stukalova

    2015-01-01

    Full Text Available Rationale: Atrial fibrillation (AF is the most common type of arrhythmia. Left atrial abnormalities in AF require further investigation.Aim: To evaluate characteristics of myocardial structure of the left atrium by magnetic resonance imaging (MRI with delayed contrast enhancement in patients with AF associated with essential hypertension (EH, in those without any cardiovascular disorders, and in patients with AF after cryoablation of the pulmonary artery orifice.Materials and methods: The study enrolled 53 patients with AF (mean age 56 years. Twenty eight of them had AF without any associated cardiovascular disorders (lone AF, or LAF group, 25 patients had AF related to EH (AF + EH group. Three patients had undergone anti-arrhythmic intervention. Cardiac MRI was performed in all patients with high resolution late gadolinium enhancement (LGE at 15–20 min after i.v. gadoversetamide (0.15 mmol/kg. For LGE MRI, we used a novel high resolution inversion recovery (inversion times 290–340 ms magnetic resonance pulse sequence with isotropic voxel (size 1.25 . 1.25 .2.5 mm and fat saturation. Left atrium walls were segmented semi-automatically on the LGE images. Left atrium fibrosis quantification was performed with the original software LGE Heart Analyzer, developed in Russian Cardiology Research and Production Complex (Moscow.Results: Left atrium fibrosis (mean, 9 [1.7; 18] % was found both in patients with AF + EH and with lone AF. There was a trend towards more significant left atrial fibrosis in the group of AF + EH, compared to that in the lone AF group (10.972 [6.98; 19.366] % vs 4.37 [0.893; 18.575] %, respectively, p = 0.1. The extent of left atrium fibrosis correlated with left atrium dilatation (r = 0.37, p < 0.001 and with the decreased ejection fraction (r = -0.4, р < 0.001. The patients who had undergone an antiarrhythmic intervention, demonstrated formation of intensive LGE zones in the ablation areas.Conclusion: Quantification of

  3. Applying non-linear dynamics to atrial appendage flow data to understand and characterize atrial arrhythmia

    International Nuclear Information System (INIS)

    Chandra, S.; Grimm, R.A.; Katz, R.; Thomas, J.D.

    1996-01-01

    The aim of this study was to better understand and characterize left atrial appendage flow in atrial fibrillation. Atrial fibrillation and flutter are the most common cardiac arrhythmias affecting 15% of the older population. The pulsed Doppler velocity profile data was recorded from the left atrial appendage of patients using transesophageal echocardiography. The data was analyzed using Fourier analysis and nonlinear dynamical tools. Fourier analysis showed that appendage mechanical frequency (f f ) for patients in sinus rhythm was always lower (around1 Hz) than that in atrial fibrillation (5-8 Hz). Among patients with atrial fibrillation spectral power below f f was significantly different suggesting variability within this group of patients. Results that suggested the presence of nonlinear dynamics were: a) the existence of two arbitrary peak frequencies f 1 , f 2 , and other peak frequencies as linear combinations thereof (mf 1 ±nf 2 ), and b) the similarity between the spectrum of patient data and that obtained using the Lorenz equation. Nonlinear analysis tools, including Phase plots and differential radial plots, were also generated from the velocity data using a delay of 10. In the phase plots, some patients displayed a torus-like structure, while others had a more random-like pattern. In the differential radial plots, the first set of patients (with torus-like phase plots) showed fewer values crossing an arbitrary threshold of 10 than did the second set (8 vs. 27 in one typical example). The outcome of cardioversion was different for these two set of patients. Fourier analysis helped to: differentiate between sinus rhythm and atrial fibrillation, understand the characteristics of the wide range of atrial fibrillation patients, and provide hints that atrial fibrillation could be a nonlinear process. Nonlinear dynamical tools helped to further characterize and sub-classify atrial fibrillation

  4. Early changes in left atrial volume after acute myocardial infarction

    DEFF Research Database (Denmark)

    Bakkestrom, R.; Andersen, Mads J; Ersboll, M.

    2016-01-01

    . The objective was to assess changes in LA volume early after MI in patients with diastolic dysfunction and the relation to invasive hemodynamics and natriuretic peptides. Methods: 62 patients with left ventricle ejection fraction (LVEF) >= 45%, diastolic E/e' > 8 and LA volume index >34 ml/m(2) within 48 h......Background: Dilatation of left atrium (LA) reflects chronic LA pressure or volume overload that possesses considerable prognostic information. Little is known regarding the interaction between LA remodeling after acute myocardial infarction (MI) and left atrial pressure at rest and during exercise...... of MI were enrolled. After 1 and 4 months blood sampling, echocardiography and right heart catheterization were performed during exercise test. Results: LA remodeling was considered in patients with a change from mild (35-41 ml/m(2)), to severe (>48ml/m(2)) dilatation after 4 months (Found in 22...

  5. Atrial tachyarrhythmia in adult congenital heart disease

    Science.gov (United States)

    Karbassi, Arsha; Nair, Krishnakumar; Harris, Louise; Wald, Rachel M; Roche, S Lucy

    2017-01-01

    The adult congenital heart disease (ACHD) population continues to grow and most cardiologists, emergency room physicians and family doctors will intermittently come into contact with these patients. Oftentimes this may be in the setting of a presentation with atrial tachyarrhythmia; one of the commonest late complications of ACHD and problem with potentially serious implications. Providing appropriate initial care and ongoing management of atrial tachyarrhythmia in ACHD patients requires a degree of specialist knowledge and an awareness of certain key issues. In ACHD, atrial tachyarrhythmia is usually related to the abnormal anatomy of the underlying heart defect and often occurs as a result of surgical scar or a consequence of residual hemodynamic or electrical disturbances. Arrhythmias significantly increase mortality and morbidity in ACHD and are the most frequent reason for ACHD hospitalization. Intra-atrial reentrant tachycardia and atrial fibrillation are the most prevalent type of arrhythmia in this patient group. In hemodynamically unstable patients, urgent cardioversion is required. Acute management of the stable patient includes anticoagulation, rate control, and electrical or pharmacological cardioversion. In ACHD, rhythm control is the preferred management strategy and can often be achieved. However, in the long-term, medication side-effects can prove problematic. Electrophysiology studies and catheter ablation are important treatments modalities and in certain cases, surgical or percutaneous treatment of the underlying cardiac defect has a role. ACHD patients, especially those with complex CHD, are at increased risk of thromboembolic events and anticoagulation is usually required. Female ACHD patients of child bearing age may wish to pursue pregnancies. The risk of atrial arrhythmias is increased during pregnancy and management of atrial tachyarrhythmia during pregnancy needs specific consideration. PMID:28706585

  6. Spectral of electrocardiographic RR intervals to indicate atrial fibrillation

    Science.gov (United States)

    Nuryani, Nuryani; Satrio Nugroho, Anto

    2017-11-01

    Atrial fibrillation is a serious heart diseases, which is associated on the risk of death, and thus an early detection of atrial fibrillation is necessary. We have investigated spectral pattern of electrocardiogram in relation to atrial fibrillation. The utilized feature of electrocardiogram is RR interval. RR interval is the time interval between a two-consecutive R peaks. A series of RR intervals in a time segment is converted to a signal with a frequency domain. The frequency components are investigated to find the components which significantly associate to atrial fibrillation. A segment is defined as atrial fibrillation or normal segments by considering a defined number of atrial fibrillation RR in the segment. Using clinical data of 23 patients with atrial fibrillation, we find that the frequency components could be used to indicate atrial fibrillation.

  7. Risk of atrial fibrillation and stroke in rheumatoid arthritis

    DEFF Research Database (Denmark)

    Lindhardsen, Jesper; Ahlehoff, Ole; Gislason, Gunnar Hilmar

    2012-01-01

    To determine if patients with rheumatoid arthritis have increased risk of atrial fibrillation and stroke.......To determine if patients with rheumatoid arthritis have increased risk of atrial fibrillation and stroke....

  8. Treatment Guidelines of Atrial Fibrillation (AFib or AF)

    Science.gov (United States)

    ... Artery Disease Venous Thromboembolism Aortic Aneurysm More Treatment Guidelines of Atrial Fibrillation (AFib or AF) Updated:Jun 28,2017 What are the treatment guidelines for atrial fibrillation? Medical guidelines are written by ...

  9. 3D patient-specific models for left atrium characterization to support ablation in atrial fibrillation patients.

    Science.gov (United States)

    Valinoti, Maddalena; Fabbri, Claudio; Turco, Dario; Mantovan, Roberto; Pasini, Antonio; Corsi, Cristiana

    2018-01-01

    Radiofrequency ablation (RFA) is an important and promising therapy for atrial fibrillation (AF) patients. Optimization of patient selection and the availability of an accurate anatomical guide could improve RFA success rate. In this study we propose a unified, fully automated approach to build a 3D patient-specific left atrium (LA) model including pulmonary veins (PVs) in order to provide an accurate anatomical guide during RFA and without PVs in order to characterize LA volumetry and support patient selection for AF ablation. Magnetic resonance data from twenty-six patients referred for AF RFA were processed applying an edge-based level set approach guided by a phase-based edge detector to obtain the 3D LA model with PVs. An automated technique based on the shape diameter function was designed and applied to remove PVs and compute LA volume. 3D LA models were qualitatively compared with 3D LA surfaces acquired during the ablation procedure. An expert radiologist manually traced the LA on MR images twice. LA surfaces from the automatic approach and manual tracing were compared by mean surface-to-surface distance. In addition, LA volumes were compared with volumes from manual segmentation by linear and Bland-Altman analyses. Qualitative comparison of 3D LA models showed several inaccuracies, in particular PVs reconstruction was not accurate and left atrial appendage was missing in the model obtained during RFA procedure. LA surfaces were very similar (mean surface-to-surface distance: 2.3±0.7mm). LA volumes were in excellent agreement (y=1.03x-1.4, r=0.99, bias=-1.37ml (-1.43%) SD=2.16ml (2.3%), mean percentage difference=1.3%±2.1%). Results showed the proposed 3D patient-specific LA model with PVs is able to better describe LA anatomy compared to models derived from the navigation system, thus potentially improving electrograms and voltage information location and reducing fluoroscopic time during RFA. Quantitative assessment of LA volume derived from our 3D LA

  10. Rising rates of hospital admissions for atrial fibrillation

    DEFF Research Database (Denmark)

    Friberg, Jens; Buch, Nina Pernille Gardshodn; Scharling, Henrik

    2003-01-01

    Atrial fibrillation is a common arrhythmia associated with excess morbidity and mortality. We studied temporal changes in hospital admission rates for atrial fibrillation using data from a prospective population-based cohort study spanning 2 decades (the Copenhagen City Heart Study).......Atrial fibrillation is a common arrhythmia associated with excess morbidity and mortality. We studied temporal changes in hospital admission rates for atrial fibrillation using data from a prospective population-based cohort study spanning 2 decades (the Copenhagen City Heart Study)....

  11. Giant right atrial myxoma: characterization with cardiac magnetic resonance imaging.

    LENUS (Irish Health Repository)

    Ridge, Carole A

    2012-02-01

    A 53-year-old woman presented to the emergency department with a 2-week history of dyspnoea and chest pain. Computed tomography pulmonary angiography was performed to exclude acute pulmonary embolism (PE). This demonstrated a large right atrial mass and no evidence of PE. Transthoracic echocardiography followed by cardiac magnetic resonance imaging confirmed a mobile right atrial mass. Surgical resection was then performed confirming a giant right atrial myxoma. We describe the typical clinical, radiologic, and pathologic features of right atrial myxoma.

  12. Electrical remodeling and atrial dilation during atrial tachycardia are influenced by ventricular rate : Role of developing tachycardiomyopathy

    NARCIS (Netherlands)

    Schoonderwoerd, BA; Van Gelder, IC; Van Veldhuisen, DJ; Tieleman, RG; Grandjean, JG; Bel, KJ; Allessie, MA; Crijns, HJGM

    2001-01-01

    Atrial Remodeling in Tachycardiomyopathy. Introduction: Atrial fibrillation (AF) and congestive heart failure (CHF) are two clinical entities that often coincide. Our aim was to establish the influence of concomitant high ventricular rate and consequent development of CHF on electrical remodeling

  13. Ventricular myocarditis coincides with atrial myocarditis in patients

    NARCIS (Netherlands)

    Begieneman, Mark P. V.; Emmens, Reindert W.; Rijvers, Liza; Kubat, Bela; Paulus, Walter J.; Vonk, Alexander B. A.; Rozendaal, Lawrence; Biesbroek, P. Stefan; Wouters, Diana; Zeerleder, Sacha; van Ham, Marieke; Heymans, Stephane; van Rossum, Albert C.; Niessen, Hans W. M.; Krijnen, Paul A. J.

    2016-01-01

    Atrial fibrillation (AF) is a common complication in myocarditis. Atrial inflammation has been suggested to play an important role in the pathophysiology of AF. However, little is known about the occurrence of atrial inflammation in myocarditis patients. Here, we analyzed inflammatory cell numbers

  14. Atrial electromechanical delay in patients undergoing heart transplantation

    Directory of Open Access Journals (Sweden)

    Mustafa Bulut, MD

    2017-04-01

    Conclusion: Inter-AEMD and intra-AEMD were prolonged in patients who underwent heart transplantation as compared to a control population. This may explain the increased atrial fibrillation and other atrial arrhythmia incidences associated with the biatrial anastomosis heart transplantation technique and may contribute to the treatment of atrial fibrillation in this special patient group.

  15. A Therapeutic Challenge: Management of Atrial Thrombus

    Directory of Open Access Journals (Sweden)

    Serkan Burc Deser

    2016-09-01

    Full Text Available Introduction: Primary cause of atrial thrombi include atrial fibrillation, foreign bodies inside the atrium such as catheters and pacemaker leads, emboli of deep venous thrombus and primary or metastatic tumors of the heart. We review the clinical features, epidemiology, diagnosis and treatment of nine intriguing cases with atrial thrombus. Methods: This is a retrospective study of nine patients (seven female (78%, two male (33% who were diagnosed with atrial thrombi (average age of 50 ± 12 years and were treated at the Ondokuz Mayis University, Department of Cardiovascular Surgery from February 2014 to January 2015. Among them, six patients had atrial fibrillation (one male, five female, seven patients were suffering from dispne and orthopnoea, five patients were suffering from leg swelling, seven patients had a history of hypertension and three patients had a history of mitral valve replacement surgery. Results: All patients underwent surgery except one. Four patients recovered uneventfully and discharged with oral anticoagulation (warfarin therapy (adjusted to maintain an international normalized ratio of INR between two and three times. Five of nine patients (55% died after surgery. Conclusion: The response to the thrombolytic therapy is poor, mostly ineffective and unsafe so it is often recommended as a bridge to surgery. In patients diagnosed with mechanical mitral valve thrombosis, medical therapy has the possibility of end organ emboli and also fail to resolve the organised thrombus on the stuck valve. On the other hand surgery does not always give satisfactory results. J Clin Exp Invest 2016; 7(4: 278-282

  16. Atrial antitachycardia pacing and atrial remodeling: A substudy of the international, randomized MINERVA trial.

    Science.gov (United States)

    Boriani, Giuseppe; Tukkie, Raymond; Biffi, Mauro; Mont, Lluis; Ricci, Renato; Pürerfellner, Helmut; Botto, Giovanni Luca; Manolis, Antonis S; Landolina, Maurizio; Gulizia, Michele; Hudnall, J Harrison; Mangoni, Lorenza; Grammatico, Andrea; Padeletti, Luigi

    2017-10-01

    Atrial tachycardia (AT) and atrial fibrillation (AF) are common in pacemaker patients and are associated with bad prognoses. The purpose of this study was to evaluate atrial antitachycardia pacing impact on AT/AF-induced atrial remodeling, measured by early recurrence of AT/AF (ERAF) and by change in left atrial diameter (LAD), and to evaluate the impact of AT/AF duration on ERAF incidence. Pacemaker patients were randomized to dual-chamber pacing (Control DDDR: 385 patients), managed ventricular pacing (MVP: 398 patients), or atrial antitachycardia pacing plus MVP (DDDRP+MVP: 383 patients). LAD change, estimated by echocardiography, was considered significant if the relative difference between baseline and 24-month measurements was >10%. At median follow-up of 34 months, ERAF incidence was significantly lower in the DDDRP+MVP arm for all AT/AF durations, in particular, ERAF followed AT/AF longer than 3 hours in 53% cases in Control DDDR, in 51% cases in MVP, and in 39% cases in DDDRP+MVP (P MVP, and 70% in DDDRP+MVP (P MVP, DDDRP+MVP reduces ERAF and favors LAD reduction, suggesting that atrial antitachycardia pacing may reverse electrical and mechanical remodeling. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  17. Left atrial size and function as predictors of new-onset of atrial fibrillation in patients with asymptomatic aortic stenosis

    DEFF Research Database (Denmark)

    Bang, Casper Niels Furbo; Dalsgaard, Morten; Greve, Anders

    2013-01-01

    Left atrial (LA) size and function change with chronically increased left ventricular (LV) filling pressures. It remains unclear whether these variations in LA parameters can predict new-onset atrial fibrillation (AF) in asymptomatic patients with aortic stenosis (AS).......Left atrial (LA) size and function change with chronically increased left ventricular (LV) filling pressures. It remains unclear whether these variations in LA parameters can predict new-onset atrial fibrillation (AF) in asymptomatic patients with aortic stenosis (AS)....

  18. Epidemiological study of dilated cardiomyopathy from eastern India with special reference to left atrial size

    Directory of Open Access Journals (Sweden)

    Rudrajit Paul, Saumen Nandi, Pradip K Sinha

    2014-07-01

    Full Text Available Dilated cardiomyopathy (DCM is a common cause of emergency visit in our country. The disease is often misdiagnosed and mistreated. There are very few studies on DCM from India. We undertook a small study on DCM patients from Eastern India to find the demographic and echocardiographic characteristics. Patients and methods: We under took this study in a tertiary care Medical College of Eastern India. All patients coming to the emergency with dyspnea were evaluated for cardiac dysfunction. Emergency echocardiography was done to diagnose dilated cardiomyopathy. Patients with DCM were then evaluated as per protocol. After stabilization, echocardiography was repeated to note the study parameters like left atrial diameter. Standard statistical tests were used. Results: we had a total of 70 patients in our study with a male: female ratio of 43:27. Most patients were aged over 40 years. Patients with COPD, history of radiation, malignancy or drug abuse were excluded. Most patients (47% were on NYHA stage 3 at the time of presentation. In our patient cohort, 24% were alcoholic and 46% were smokers. Atrial fibrillation was present in 15.7% of the patients and right and left bundle branch block had been present in 8 and 15 patients respectively. In echocardiography, increased left atrial (LA size (>40 mm was found in 45 patients. Many patients had valvular regurgitation, mitral, aortic or tricuspid. LA size was positively correlated with left ventricular systolic diameter (r=0.403 and negatively correlated with ejection fraction (r= -0.23. Analysis and conclusion: different ECG abnormalities like bundle branch block and arrhythmias like atrial fibrillation are quite common in DCM. In echocardiography, left atrial size is an important prognostic marker and correlates with left ventricular function.

  19. Pulmonary Vein, Dorsal Atrial Wall and Atrial Septum Abnormalities in Podoplanin Knockout Mice With Disturbed Posterior Heart Field Contribution

    NARCIS (Netherlands)

    Douglas, Yvonne L.; Mahtab, Edris A. F.; Jongbloed, Monique R. M.; Uhrin, Pavel; Zaujec, Jan; Binder, Bernd R.; Schalij, Martin J.; Poelmann, Robert E.; Deruiter, Marco C.; Gittenberger-De Groot, Adriana C.

    The developing sinus venosus myocardium, derived from the posterior heart field, contributes to the atrial septum, the posterior atrial wall, the sino-atrial node, and myocardium lining the pulmonary and cardinal veins, all expressing podoplanin, a coelomic and myocardial marker. . We compared

  20. Role of atrial endothelial cells in the development of atrial fibrosis and fibrillation in response to pressure overload.

    Science.gov (United States)

    Kume, Osamu; Teshima, Yasushi; Abe, Ichitaro; Ikebe, Yuki; Oniki, Takahiro; Kondo, Hidekazu; Saito, Shotaro; Fukui, Akira; Yufu, Kunio; Miura, Masahiro; Shimada, Tatsuo; Takahashi, Naohiko

    Monocyte chemoattractant protein-1 (MCP-1)-mediated inflammatory mechanisms have been shown to play a crucial role in atrial fibrosis induced by pressure overload. In the present study, we investigated whether left atrial endothelial cells would quickly respond structurally and functionally to pressure overload to trigger atrial fibrosis and fibrillation. Six-week-old male Sprague-Dawley rats underwent suprarenal abdominal aortic constriction (AAC) or a sham operation. By day 3 after surgery, macrophages were observed to infiltrate into the endocardium. The expression of MCP-1 and E-selectin in atrial endothelium and the expression of intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and ED1 in left atrial tissue were enhanced. Atrial endothelial cells were irregularly hypertrophied with the disarrangement of lines of cells by scanning electron microscopy. Various-sized gap formations appeared along the border in atrial endothelial cells, and several macrophages were located just in the endothelial gap. Along with the development of heterogeneous interstitial fibrosis, interatrial conduction time was prolonged and the inducibility of atrial fibrillation by programmed extrastimuli was increased in the AAC rats compared to the sham-operated rats. Atrial endothelium responds rapidly to pressure overload by expressing adhesion molecules and MCP-1, which induce macrophage infiltration into the atrial tissues. These processes could be an initial step in the development of atrial remodeling for atrial fibrillation. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Increased susceptibility to atrial fibrillation secondary to atrial fibrosis in transgenic goats expressing transforming growth factor - B1

    Science.gov (United States)

    Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in people with significant morbidity and mortality. There is a strong association between atrial fibrosis and AF. Transforming growth factor B1 (TGF-B1) is an essential mediator of atrial fibrosis in animal models and human pat...

  2. 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...... electroanatomic LA mapping, and all pulmonary vein ostia were marked under the help of pulmonary veins angiography on the 3D map. Radiofrequency (RF) energy was delivered to create continuous linear lesions encircling the pulmonary veins, it was delivered with a target temperature of 43¿, a maximal power limit...

  3. Evaluation of left atrial function by multidetector computed tomography before left atrial radiofrequency-catheter ablation: Comparison of a manual and automated 3D volume segmentation method

    International Nuclear Information System (INIS)

    Wolf, Florian; Ourednicek, Petr; Loewe, Christian; Richter, Bernhard; Goessinger, Heinz David; Gwechenberger, Marianne; Plank, Christina; Schernthaner, Ruediger Egbert; Toepker, Michael; Lammer, Johannes; Feuchtner, Gudrun M.

    2010-01-01

    Introduction: The purpose of this study was to compare a manual and automated 3D volume segmentation tool for evaluation of left atrial (LA) function by 64-slice multidetector-CT (MDCT). Methods and materials: In 33 patients with paroxysmal atrial fibrillation a MDCT scan was performed before radiofrequency-catheter ablation. Atrial function (minimal volume (LAmin), maximal volume (LAmax), stroke volume (SV), ejection fraction (EF)) was evaluated by two readers using a manual and an automatic tool and measurement time was evaluated. Results: Automated LA volume segmentation failed in one patient due to low LA enhancement (103HU). Mean LAmax, LAmin, SV and EF were 127.7 ml, 93 ml, 34.7 ml, 27.1% by the automated, and 122.7 ml, 89.9 ml, 32.8 ml, 26.3% by the manual method with no significant difference (p > 0.05) and high Pearsons correlation coefficients (r = 0.94, r = 0.94, r = 0.82 and r = 0.85, p < 0.0001), respectively. The automated method was significantly faster (p < 0.001). Interobserver variability was low for both methods with Pearson's correlation coefficients between 0.98 and 0.99 (p < 0.0001). Conclusions: Evaluation of LA volume and function with 64-slice MDCT is feasible with a very low interobserver variability. The automatic method is as accurate as the manual method but significantly less time consuming permitting a routine use in clinical practice before RF-catheter ablation.

  4. 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...... alcohol than people with low risk. METHODS: We used data for a total of 88,782 men and women from the Copenhagen City Heart Study 1991-1994 and 2001-2003 and the Copenhagen General Population Study 2003-2010. Information on incident cases of atrial fibrillation was obtained from a validated nationwide...... 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...

  5. The atrial fibrillation ablation pilot study

    DEFF Research Database (Denmark)

    Arbelo, Elena; Brugada, Josep; Hindricks, Gerhard

    2014-01-01

    AIMS: The Atrial Fibrillation Ablation Pilot Study is a prospective registry designed to describe the clinical epidemiology of patients undergoing an atrial fibrillation (AFib) ablation, and the diagnostic/therapeutic processes applied across Europe. The aims of the 1-year follow-up were to analyse...... was achieved in 40.7% of patients (43.7% in paroxysmal AF; 30.2% in persistent AF; 36.7% in long-lasting persistent AF). A second ablation was required in 18% of the cases and 43.4% were under antiarrhythmic treatment. Thirty-three patients (2.5%) suffered an adverse event, 272 (21%) experienced a left atrial...... tachycardia, and 4 patients died (1 haemorrhagic stroke, 1 ventricular fibrillation in a patient with ischaemic heart disease, 1 cancer, and 1 of unknown cause). CONCLUSION: The AFib Ablation Pilot Study provided crucial information on the epidemiology, management, and outcomes of catheter ablation of AFib...

  6. Antihypertensive treatment and risk of atrial fibrillation

    DEFF Research Database (Denmark)

    Marott, Sarah C W; Nielsen, Sune F; Benn, Marianne

    2014-01-01

    AIMS: To examine the associations between antihypertensive treatment with angiotensin-converting enzyme inhibitors (ACEis) or angiotensin receptor blockers (ARBs), β-blockers, diuretics, or calcium-antagonists, and risk of atrial fibrillation. We examined these associations using the entire Danish...... population from 1995 through 2010. METHODS AND RESULTS: Excluding medication used in atrial fibrillation, we matched individuals on ACEi monotherapy 1:1 with individuals on β-blocker (n = 48 658), diuretic (n = 69 630), calcium-antagonist (n = 57 646), and ARB monotherapy (n = 20 158). Likewise, individuals...... on ARB monotherapy were matched 1:1 with individuals on β-blocker (n = 20 566), diuretic (n = 20 832), calcium-antagonist (n = 20 232), and ACEi monotherapy (n = 20 158). All were free of atrial fibrillation and of predisposing diseases like heart failure, ischaemic heart disease, diabetes mellitus...

  7. Sensitivity and specificity of radionuclide equilibrium angiocardiography for detection of hemodynamically significant secundum atrial septal defect

    Energy Technology Data Exchange (ETDEWEB)

    Brunotte, F.; Laurens, M.H.; Itty, C.; Robert, J.; Cloez, J.L.; Marcon, F.; Pernot, C.

    1986-12-01

    To determine the value, of gated equilibrium angiography in secundum atrial septal defect (ASD) in children, the first pass pulmonic/systemic flow ratio (Qp/Qs) was compared with diastolic count ratio (DCR) and stroke count ratio (SCR) of the two ventricles. In 50 children we have found a correlation between Qp/Qs and DCR (r=0.71) and between Qp/Qs and SCR (r=0.66). For detection of significant atrial shunt (Qp/Qs>1.5) the sensitivity of DCR>2 was 0.81 and the specificity 0.75. For SCR>1.5 we sensitivity and specificity values of 0.87 and 0.71 respectively. Left and right ventricular ejection fractions were normal (0.67+-0.08 and 0.50+-0.07).

  8. Exercise-based cardiac rehabilitation for adults with atrial fibrillation

    DEFF Research Database (Denmark)

    Risom, Signe Stelling; Zwisler, Ann-Dorthe; Johansen, Pernille Palm

    2017-01-01

    BACKGROUND: Exercise-based cardiac rehabilitation may benefit adults with atrial fibrillation or those who had been treated for atrial fibrillation. Atrial fibrillation is caused by multiple micro re-entry circuits within the atrial tissue, which result in chaotic rapid activity in the atria....... OBJECTIVES: To assess the benefits and harms of exercise-based rehabilitation programmes, alone or with another intervention, compared with no-exercise training controls in adults who currently have AF, or have been treated for AF. SEARCH METHODS: We searched the following electronic databases; CENTRAL...... the benefits and harms of exercise-based cardiac rehabilitation for adults with atrial fibrillation on patient-relevant outcomes....

  9. Patients with atrial fibrillation and permanent pacemaker

    DEFF Research Database (Denmark)

    Dalgaard, Frederik; Ruwald, Martin H; Lindhardt, Tommi Bo

    2018-01-01

    BACKGROUND: The management of patients with non-valvular atrial fibrillation (NVAF) with rate-lowering or anti-arrhythmic drugs has markedly changed over the last decade, but it is unknown how these changes have affected patients with NVAF with a permanent pacemaker (PPM). METHODS: Through Danish......,261. Thus, the proportional amount of NVAF patients with a PPM decreased from 1.3% to 1.1% (p = 0.015). Overall 45.9% had atrial fibrillation (AF) duration less than one year and the proportion declined from 55.5% to 42.4% (p

  10. Atrial fibrillation and risk of stroke

    DEFF Research Database (Denmark)

    Christiansen, Christine Benn; Gerds, Thomas A.; Olesen, Jonas Bjerring

    2016-01-01

    AIM: Although the relation between stroke risk factors and stroke in patients with atrial fibrillation (AF) has been extensively examined, only few studies have explored the association of AF and the risk of ischaemic stroke/systemic thromboembolism/transient ischaemic attack (stroke.......5-10.6), and 15.4% (14.5-16.4), respectively. CONCLUSIONS: Stroke/TE/TIA risk was particularly increased when prior stroke/TE/TIA was present. Atrial fibrillation is associated with an increase in risk of stroke/TE/TIA in the absence of other risk factors but only a moderate increase in risk when other risk...

  11. Integrating new approaches to atrial fibrillation management

    DEFF Research Database (Denmark)

    Kotecha, Dipak; Breithardt, Günter; Camm, A John

    2018-01-01

    There are major challenges ahead for clinicians treating patients with atrial fibrillation (AF). The population with AF is expected to expand considerably and yet, apart from anticoagulation, therapies used in AF have not been shown to consistently impact on mortality or reduce adverse...... of the Atrial Fibrillation Network (AFNET) and the European Heart Rhythm Association (EHRA), held at the European Society of Cardiology Heart House in Sophia Antipolis, France, 17-19 January 2017. Sixty-two global specialists in AF and 13 industry partners met to develop innovative solutions based on new...

  12. Initiation of anticoagulation in atrial fibrillation

    DEFF Research Database (Denmark)

    Gundlund, A.; Staerk, L.; Fosbøl, E. L.

    2017-01-01

    Background: The use of non-vitamin K antagonist oral anticoagulants (NOACs) for stroke prophylaxis in atrial fibrillation (AF) is increasing rapidly. We compared characteristics of AF patients initiated on NOACs versus vitamin K antagonists (VKAs). Methods: Using Danish nationwide registry data, we...... compared with a VKA [odds ratio (OR) 1.35, 95% confidence interval (CI) 1.28–1.43]. By contrast, patients with a history of myocardial infarction were less likely to be initiated on a NOAC compared with a VKA (OR 0.72, 95% CI 0.67–0.77). Conclusions: Atrial fibrillation patients who were initiated...

  13. Cryoballoon Catheter Ablation in Atrial Fibrillation

    Directory of Open Access Journals (Sweden)

    Cevher Ozcan

    2011-01-01

    Full Text Available Pulmonary vein isolation with catheter ablation is an effective treatment in patients with symptomatic atrial fibrillation refractory or intolerant to antiarrhythmic medications. The cryoballoon catheter was recently approved for this procedure. In this paper, the basics of cryothermal energy ablation are reviewed including its ability of creating homogenous lesion formation, minimal destruction to surrounding vasculature, preserved tissue integrity, and lower risk of thrombus formation. Also summarized here are the publications describing the clinical experience with the cryoballoon catheter ablation in both paroxysmal and persistent atrial fibrillation, its safety and efficacy, and discussions on the technical aspect of the cryoballoon ablation procedure.

  14. Atrial fibrillation and the 4P medicine.

    Science.gov (United States)

    Censi, Federica; Cianfrocca, Cinzia; Purificato, Ivana

    2013-01-01

    Although the paradigm of the 4P medicine - Predictive, Personalized, Preemptive, and Participatory - has been suggested several years ago, its application to atrial fibrillation is still far away. Given the increasing prevalence and incidence of this pathology it is the time to promote preventive strategies, by identifying the risk factors associated to life style and by incentivizing innovative diagnostic technologies. The promotion of the correct life style and of the use of diagnostic devices based on innovative and reliable technologies, represent a first step towards the full realization of the revolution of 4P medicine in atrial fibrillation.

  15. Atrial fibrillation and the 4P medicine

    Directory of Open Access Journals (Sweden)

    Federica Censi

    2013-09-01

    Full Text Available Although the paradigm of the 4P medicine - Predictive, Personalized, Preemptive, and Participatory - has been suggested several years ago, its application to atrial fibrillation is still far away. Given the increasing prevalence and incidence of this pathology it is the time to promote preventive strategies, by identifying the risk factors associated to life style and by incentivizing innovative diagnostic technologies. The promotion of the correct life style and of the use of diagnostic devices based on innovative and reliable technologies, represent a first step towards the full realization of the revolution of 4P medicine in atrial fibrillation.

  16. Posibilities of cardiac pacemaker use in paroxsysmal atrial fibrilation

    Directory of Open Access Journals (Sweden)

    Borut Kamenik

    2005-12-01

    Full Text Available Background: Prevention of atrial fibrillation is a big therapeutic challenge because of all known negative consequences of this the most frequent cardiac arrhythmia. Numerous of clinical studies showed bad control or ineffectiveness of antiarhythmic drugs. Nonfarmakological therapies like surgical treatment, radiofrequency ablation and atrial pacing are being tested. Effectiveness of atrial pacing in prevention of paroxysmal artial fibrillation has been documented in numerous prospective studies and is effective for a long time interval, but only for patients with bradicardic underlying cardiac rhythm. In Normocardic rhythm or normal AV conduction the effective Atrial fibrillation prevention was not proven. The mechanism of action is based on premature atrial complex suppression, reduction of dispersion of refractoriness after short-long cycles and reduction of interatrial conduction delay. The atrial stimulation site or multi-site atrial pacing could be effective in AF prevention when interatrial conduction delay is present; otherwise the difference is not significant.Conclusions: In bradicardic patient who has frequent paroxysms of atrial fibrillation, regardless if bradycardia is due to ineffective antiarrhythmic drug treathement, implantation of DDDR pacemaker with atrial prevention algorhythm is indicated. If the P-wave duration is >120 milliseconds multi-site atrial pacing or septal atrial pacing should be considered. Pacemaker diagnostic tools could be used for adequate start of anticoagulant therapy and control of effectiveness of anthyarhythmic drug therapy.

  17. Embolic Risk in Atrial Fibrillation that Arises from Hyperthyroidism

    Science.gov (United States)

    Traube, Elie; Coplan, Neil L.

    2011-01-01

    Atrial fibrillation, the most common cardiac complication of hyperthyroidism, occurs in an estimated 10% to 25% of overtly hyperthyroid patients. The prevalence of atrial fibrillation increases with age in the general population and in thyrotoxic patients. Other risk factors for atrial fibrillation in thyrotoxic patients include male sex, ischemic or valvular heart disease, and congestive heart failure. The incidence of arterial embolism or stroke in thyrotoxic atrial fibrillation is less clear. There are many reports of arterial thromboembolism associated with hyperthyroidism, including cases of young adults without coexisting risk factors other than thyrotoxic atrial fibrillation. The use of anticoagulative agents to prevent thromboembolic sequelae of thyrotoxic atrial fibrillation is controversial: national organizations provide conflicting recommendations in their practice guidelines. Herein, we review the medical literature and examine the evidence behind the recommendations in order to determine the best approach to thromboembolic prophylaxis in patients who have atrial fibrillation that is associated with hyperthyroidism. PMID:21720457

  18. New risk factors for atrial fibrillation : causes of 'not-so-lone atrial fibrillation'

    NARCIS (Netherlands)

    Schoonderwoerd, Bas A.; Smit, Marcelle D.; Pen, Lucas; Van Gelder, Isabelle C.

    Atrial fibrillation (AF) is a prevalent arrhythmia in patients with cardiovascular disease. The classical risk factors for developing AF include hypertension, valvular disease, (ischaemic) cardiomyopathy, diabetes mellitus, and thyroid disease. In some patients with AF, no underlying

  19. Left atrial size in patients with cryptogenic stroke as a predictor of occurrence of atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Antonio Cruz Culebras

    2017-04-01

    Full Text Available Objective: To determine whether the left atrial size can predict the development of atrial fibrillation (AF in patients with embolic stroke of undetermined source (ESUS. Methods: Patients with ischemic stroke were included prospectively (January 2015-July 2015 when ESUS was suspected. Clinical and cardiac imaging data were recorded. Patients with cardiac failure were excluded. Results: a total of 55 patients were included. Medium age was 71 years. The proportion of patients who developed AF during the follow-up (1 year was 23, 63%. 10 % of patients did not have any vascular risk factor. Basal ECG was normal in 98% of cases. The left atrial size volume was 36, 08 ml in patients who developed AF and 27, 14 ml in patients who did not. Conclusions: In patients with ESUS, left atrial size dimensions do not predict the occurrence of AF.

  20. Left atrial low-voltage areas predict atrial fibrillation recurrence after catheter ablation in patients with paroxysmal atrial fibrillation.

    Science.gov (United States)

    Masuda, Masaharu; Fujita, Masashi; Iida, Osamu; Okamoto, Shin; Ishihara, Takayuki; Nanto, Kiyonori; Kanda, Takashi; Tsujimura, Takuya; Matsuda, Yasuhiro; Okuno, Shota; Ohashi, Takuya; Tsuji, Aki; Mano, Toshiaki

    2018-04-15

    Association between the presence of left atrial low-voltage areas and atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) has been shown mainly in persistent AF patients. We sought to compare the AF recurrence rate in paroxysmal AF patients with and without left atrial low-voltage areas. This prospective observational study included 147 consecutive patients undergoing initial ablation for paroxysmal AF. Voltage mapping was performed after PVI during sinus rhythm, and low-voltage areas were defined as regions where bipolar peak-to-peak voltage was low-voltage areas after PVI were observed in 22 (15%) patients. Patients with low-voltage areas were significantly older (72±6 vs. 66±10, plow-voltage areas than without (36% vs. 6%, pLow-voltage areas were independently associated with AF recurrence even after adjustment for the other related factors (Hazard ratio, 5.89; 95% confidence interval, 2.16 to 16.0, p=0.001). The presence of left atrial low-voltage areas after PVI predicts AF recurrence in patients with paroxysmal AF as well as in patients with persistent AF. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Valsartan Reduced Atrial Fibrillation Susceptibility by Inhibiting Atrial Parasympathetic Remodeling through MAPKs/Neurturin Pathway

    Directory of Open Access Journals (Sweden)

    Lei Liu

    2015-07-01

    Full Text Available Background/Aims: Angiotensin II receptor blockers (ARBs have been proved to be effective in preventing atrial structural and electrical remodelinq in atrial fibrillation (AF. Previous studies have shown that parasympathetic remodeling plays an important role in AF. However, the effects of ARBs on atrial parasympathetic remodeling in AF and the underlying mechanisms are still unknown. Methods: Canines were divided into sham-operated, pacing and valsartan + pacing groups. Rats and HL-1 cardiomyocytes were divided into control, angiotensin II (Ang II and Ang II + valsartan groups, respectively. Atrial parasympathetic remodeling was quantified by immunocytochemical staining with anti-choline acetyltransferase (ChAT antibody. Western blot was used to analysis the protein expression of neurturin. Results: Both inducibility and duration were increased in chronic atrial rapid-pacing canine model, which was significantly inhibited by the treatment with valsartan. The density of ChAT-positive nerves and the protein level of neurturin in the atria of pacing canines were both increased than those in sham-operated canines. Ang II treatment not only induced atrial parasympathetic remodeling in rats, but also up-regulated the protein expression of neurturin. Valsartan significantly prevented atrial parasympathetic remodeling, and suppressed the protein expression of neurturin. Meanwhile, valsartan inhibited Ang II -induced up-regulation of neurturin and MAPKs in cultured cardiac myocytes. Inhibition of MAPKs dramatically attenuated neurturin up-regulation induced by Ang II. Conclusion: Parasympathetic remodeling was present in animals subjected to rapid pacing or Ang II infusion, which was mediated by MAPKs/neurturin pathway. Valsartan is able to prevent atrial parasympathetic remodeling and the occurrence of AF via inhibiting MAPKs/neurturin pathway.

  2. Valsartan Reduced Atrial Fibrillation Susceptibility by Inhibiting Atrial Parasympathetic Remodeling through MAPKs/Neurturin Pathway.

    Science.gov (United States)

    Liu, Lei; Geng, Jianqiang; Zhao, Hongwei; Yun, Fengxiang; Wang, Xiaoyu; Yan, Sen; Ding, Xue; Li, Wenpeng; Wang, Dingyu; Li, Jianqiang; Pan, Zhenwei; Gong, Yongtai; Tan, Xiangyang; Li, Yue

    2015-01-01

    Angiotensin II receptor blockers (ARBs) have been proved to be effective in preventing atrial structural and electrical remodelinq in atrial fibrillation (AF). Previous studies have shown that parasympathetic remodeling plays an important role in AF. However, the effects of ARBs on atrial parasympathetic remodeling in AF and the underlying mechanisms are still unknown. Canines were divided into sham-operated, pacing and valsartan + pacing groups. Rats and HL-1 cardiomyocytes were divided into control, angiotensin II (Ang II) and Ang II + valsartan groups, respectively. Atrial parasympathetic remodeling was quantified by immunocytochemical staining with anti-choline acetyltransferase (ChAT) antibody. Western blot was used to analysis the protein expression of neurturin. Both inducibility and duration were increased in chronic atrial rapid-pacing canine model, which was significantly inhibited by the treatment with valsartan. The density of ChAT-positive nerves and the protein level of neurturin in the atria of pacing canines were both increased than those in sham-operated canines. Ang II treatment not only induced atrial parasympathetic remodeling in rats, but also up-regulated the protein expression of neurturin. Valsartan significantly prevented atrial parasympathetic remodeling, and suppressed the protein expression of neurturin. Meanwhile, valsartan inhibited Ang II -induced up-regulation of neurturin and MAPKs in cultured cardiac myocytes. Inhibition of MAPKs dramatically attenuated neurturin up-regulation induced by Ang II. Parasympathetic remodeling was present in animals subjected to rapid pacing or Ang II infusion, which was mediated by MAPKs/neurturin pathway. Valsartan is able to prevent atrial parasympathetic remodeling and the occurrence of AF via inhibiting MAPKs/neurturin pathway. © 2015 S. Karger AG, Basel.

  3. 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....

  4. Left Atrial Decompression by Percutaneous Left Atrial Venting Cannula Insertion during Venoarterial Extracorporeal Membrane Oxygenation Support

    Directory of Open Access Journals (Sweden)

    Ha Eun Kim

    2016-06-01

    Full Text Available Patients with venoarterial extracorporeal membrane oxygenation (ECMO frequently suffer from pulmonary edema due to left ventricular dysfunction that accompanies left heart dilatation, which is caused by left atrial hypertension. The problem can be resolved by left atrium (LA decompression. We performed a successful percutaneous LA decompression with an atrial septostomy and placement of an LA venting cannula in a 38-month-old child treated with venoarterial ECMO for acute myocarditis.

  5. ANTIARRHYTMIC EFFICACY OF SOTALOL IN PATIENTS WITH TACHY-BRADY SYNDROME HAVING ATRIAL PACEMAKER WITH DIFFERENT ATRIAL ELECTRODE POSITION

    Directory of Open Access Journals (Sweden)

    T. N. Novikova

    2009-01-01

    Full Text Available Aim. To evaluate efficacy of the combined therapy (sotalol and constant electric cardiostimulation in AAI regimen at two atrial electrode position: in low back part of interatrial septum (IAS and in right atrial auricle (RAA.Material and methods. 20 patients with tachy-brady syndrome were examined. They were randomized in 2 groups depending on atrial electrode position. Sotalol (160 mg daily was prescribed to all patients in a month after implantation of constant atrial pacemaker (CAP. A number of atrial fibrillation paroxysms (AFP was evaluated initially, in a month after CAP implantation and in a month after start of sotalol therapy.Results. Significant AFP reduction was observed in IAS stimulation, unlike RAA stimulation. Sotalol addition had essential significance in the termination or reduction of AFP. Sotalol effect did not depend on atrial electrode position.Conclusion. Sotalol usage together with constant electric cardiostimulation significantly reduces AFP irrespectively of atrial electrode position. 

  6. Spontaneous conversion of first onset atrial fibrillation

    DEFF Research Database (Denmark)

    Lindberg, Søren Østergaard; Hansen, Sidsel; Nielsen, Tonny

    2011-01-01

    Background  We studied all patients admitted to hospital with first onset atrial fibrillation (AF) to determine the probability of spontaneous conversion to sinus rhythm and to identify factors predictive of such a conversion. Methods and Results  We retrospectively reviewed charts of 438...

  7. Genetic aspects of lone atrial fibrillation

    DEFF Research Database (Denmark)

    Andreasen, Laura; Nielsen, Jonas B; Olesen, Morten S

    2015-01-01

    Atrial fibrillation (AF) is the most common cardiac arrhythmia. A subgroup of patients presents with AF without traditional risk factors and is diagnosed before the age of 60 years. Such patients are commonly referred as having "lone AF" and comprise 10-20% of all cases. A number of studies have...

  8. Atrial fibrillation in the Middle East

    DEFF Research Database (Denmark)

    Al-Shamkhani, Warkaa; Ayetey, Harold; Lip, Gregory Y H

    2018-01-01

    INTRODUCTION: Atrial fibrillation (AF) is the commonest persistent cardiac arrhythmia with an estimated incidence rate of between 1.5-2% and an important cause of strokes. Few epidemiological studies and clinical trials on the management of AF have been conducted outside Europe and North America...

  9. An "account" of digitalis and atrial fibrillation

    NARCIS (Netherlands)

    Meijler, F.L.

    This review deals with the mechanisms by which digitalis exerts its "opium-Iike" action on the ventricular rate in patients with atrial fibrillation. To understand the effect of digitalis on ventricular rate and rhythm, it is essential to learn more about the basic electrophysiologic

  10. Fractional vector calculus for fractional advection dispersion

    Science.gov (United States)

    Meerschaert, Mark M.; Mortensen, Jeff; Wheatcraft, Stephen W.

    2006-07-01

    We develop the basic tools of fractional vector calculus including a fractional derivative version of the gradient, divergence, and curl, and a fractional divergence theorem and Stokes theorem. These basic tools are then applied to provide a physical explanation for the fractional advection-dispersion equation for flow in heterogeneous porous media.

  11. A transcatheter intracardiac shunt device for heart failure with preserved ejection fraction (REDUCE LAP-HF)

    DEFF Research Database (Denmark)

    Hasenfuß, Gerd; Hayward, Chris; Burkhoff, Dan

    2016-01-01

    BACKGROUND: Heart failure with preserved ejection fraction (HFPEF) is a common, globally recognised, form of heart failure for which no treatment has yet been shown to improve symptoms or prognosis. The pathophysiology of HFPEF is complex but characterised by increased left atrial pressure, espec...

  12. Fractional Schroedinger equation

    International Nuclear Information System (INIS)

    Laskin, Nick

    2002-01-01

    Some properties of the fractional Schroedinger equation are studied. We prove the Hermiticity of the fractional Hamilton operator and establish the parity conservation law for fractional quantum mechanics. As physical applications of the fractional Schroedinger equation we find the energy spectra of a hydrogenlike atom (fractional 'Bohr atom') and of a fractional oscillator in the semiclassical approximation. An equation for the fractional probability current density is developed and discussed. We also discuss the relationships between the fractional and standard Schroedinger equations

  13. Left atrial appendage segmentation and quantitative assisted diagnosis of atrial fibrillation based on fusion of temporal-spatial information.

    Science.gov (United States)

    Jin, Cheng; Feng, Jianjiang; Wang, Lei; Yu, Heng; Liu, Jiang; Lu, Jiwen; Zhou, Jie

    2018-05-01

    In this paper, we present an approach for left atrial appendage (LAA) multi-phase fast segmentation and quantitative assisted diagnosis of atrial fibrillation (AF) based on 4D-CT data. We take full advantage of the temporal dimension information to segment the living, flailed LAA based on a parametric max-flow method and graph-cut approach to build 3-D model of each phase. To assist the diagnosis of AF, we calculate the volumes of 3-D models, and then generate a "volume-phase" curve to calculate the important dynamic metrics: ejection fraction, filling flux, and emptying flux of the LAA's blood by volume. This approach demonstrates more precise results than the conventional approaches that calculate metrics by area, and allows for the quick analysis of LAA-volume pattern changes of in a cardiac cycle. It may also provide insight into the individual differences in the lesions of the LAA. Furthermore, we apply support vector machines (SVMs) to achieve a quantitative auto-diagnosis of the AF by exploiting seven features from volume change ratios of the LAA, and perform multivariate logistic regression analysis for the risk of LAA thrombosis. The 100 cases utilized in this research were taken from the Philips 256-iCT. The experimental results demonstrate that our approach can construct the 3-D LAA geometries robustly compared to manual annotations, and reasonably infer that the LAA undergoes filling, emptying and re-filling, re-emptying in a cardiac cycle. This research provides a potential for exploring various physiological functions of the LAA and quantitatively estimating the risk of stroke in patients with AF. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Meadow based Fraction Theory

    OpenAIRE

    Bergstra, Jan A.

    2015-01-01

    In the context of an involutive meadow a precise definition of fractions is formulated and on that basis formal definitions of various classes of fractions are given. The definitions follow the fractions as terms paradigm. That paradigm is compared with two competing paradigms for storytelling on fractions: fractions as values and fractions as pairs.

  15. Vernakalant hydrochloride for the rapid conversion of atrial fibrillation after cardiac surgery

    DEFF Research Database (Denmark)

    Kowey, Peter R; Dorian, Paul; Mitchell, L Brent

    2009-01-01

    Postoperative atrial arrhythmias are common and are associated with considerable morbidity. This study was designed to evaluate the efficacy and safety of vernakalant for the conversion of atrial fibrillation (AF) or atrial flutter (AFL) after cardiac surgery....

  16. 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.

  17. Short and middle term outcome of radiofrequency catheter ablation for paroxysmal and sustained atrial fibrillation

    International Nuclear Information System (INIS)

    Okamoto, Mitsunori; Sueda, Takashi; Hashimoto, Masaki; Fukuda, Yukihiro; Iwamoto, Akimichi; Matsumoto, Takeshi; Shintani, Yumiko; Iwasaki, Toshitaka; Kinoshita, Hiroki

    2009-01-01

    The aim of this study was to assess short and middle term outcome of radiofrequency catheter ablation for drug-refractory paroxysmal and sustained atrial fibrillation. Subjects were 30 patients of atrial fibrillation (19 paroxysmal, 11 sustained) who underwent extensive pulmonary vein isolation from January 2007 to August 2009 in our department. Twenty three men and seven women, aged from 44 to 76 years, were enrolled. Follow-up period was one to 32 months. Drug free success was 33%, but symptoms and electrocardiogram (EGG) findings were improved in 93 % of the patients by administration of anti-arrhythmic agents. Five of the six patients with bradycardia-tachycardia syndrome was free from pacemaker implantation. Left ventricular ejection fraction was improved in two patients with dilated cardiomyopathy (DCM)-like left ventricular dysfunction. One case had cardiac tamponade and transient ST elevation due to right coronary air embolism were observed in two cases. There were no death and no cerebrovascular events during the procedures and follow-up periods. In conclusion, radiofrequency catheter ablation for paroxysmal and sustained atrial fibrillation in our department may be highly acceptable new method for improving the symptoms and clinical signs of the patients. (author)

  18. Comparison of biatrial and left atrial radiofrequency ablation in patients with heart valves diseases

    Directory of Open Access Journals (Sweden)

    А. В. Богачев-прокофьев

    2015-10-01

    Full Text Available We analysed results of left atrial and biatrial anatomic scheme of radiofrequency (RF ablation of the atria in patients with valvular heart. From 2007 to 2011, RF ablation procedure performed 283 patients with atrial fibrillation and heart valve disease. Patients were divided into two groups - group I performed a complete circuit biatrial procedure (procedure maze IV - 131 patients, in group II only ablation of the left atrium -152 patients. Most of the patients had long-term persistent AF. The main problem of early postoperative period is dysfunction of pacemaker complex, which observed in 64.9% and 50.7% patients for group I and II, respectively (p = 0.031. Permanent dysfunction of pacemaker complex required implantation of permanent pacemaker (9.2% and 4.6% of cases for group I and II, respectively, p = 0,023. Predictors of dysfunction of the pacemaker complex were biatrial execution method and duration of AF. Freedom from AF and AT during 36 months after surgery was 80.4% for patients in group I and 78.5% for patients in group II, with no statistically significant difference (log-rank test, p = 0.621. Atrial transport function has not revealed that the active fraction of the right atrium was 29.8% higher than in group II in the early postoperative phase and by 17.9% in the long term, with no difference between groups for the left atrium has been received.

  19. [Atrial fibrillation as consequence and cause of structural changes of atria].

    Science.gov (United States)

    Aparina, O P; Chikhireva, L N; Stukalova, O V; Mironova, N A; Kashtanova, S Iu; Ternovoĭ, S K; Golitsyn, S P

    2014-01-01

    Changes of atrial structure and function are the contributors of atrial fibrillation clinical course, complications and treatment effectiveness. Effects of inflammation and mechanical stretch on atrial structural remodeling leading to atrial fibrillation are reviewed in the article. Contemporary invasive and non-invasive methods of evaluation (including late gadolinium enhancement magnetic resonance imaging) of patients with atrial structural remodeling in atrial fibrillation are also described.

  20. Atrial infarction is a unique and often unrecognized clinical entity

    Directory of Open Access Journals (Sweden)

    Rosana G. G. Mendes

    1999-03-01

    Full Text Available A patient with heart failure and acute atrial fibrillation received the final diagnosis of atrial infarction associated with ventricular infarction based on clinical findings of ischemia in association with atrial fibrillation and heart failure (mechanisms probably involved: contractile dysfunction and loss of atrial contribution. Although a transesophageal echocardiography, which could refine the diagnosis of anatomic abnormalities, was not performed, all evidence led to the diagnosis of atrial involvement. Electrocardiographic findings were consistent with Liu's major criterion 3. Therapy with digitalis, quinidine and angiotensin-converting enzyme inhibitors was chosen, as the patient had acute pulmonary edema. The use of beta-blockers and verapamil was restricted. No other complications, such as thrombo-embolism or atrial rupture, were noted.

  1. Cardiorespiratory interactions in patients with atrial flutter.

    Science.gov (United States)

    Masè, Michela; Disertori, Marcello; Ravelli, Flavia

    2009-01-01

    Respiratory sinus arrhythmia (RSA) is generally known as the autonomically mediated modulation of the sinus node pacemaker frequency in synchrony with respiration. Cardiorespiratory interactions have been largely investigated during sinus rhythm, whereas little is known about interactions during reentrant arrhythmias. In this study, cardiorespiratory interactions at the atrial and ventricular level were investigated during atrial flutter (AFL), a supraventricular arrhythmia based on a reentry, by using cross-spectral analysis and computer modeling. The coherence and phase between respiration and atrial (gamma(AA)(2), phi(AA)) and ventricular (gamma(RR)(2), phi(RR)) interval series were estimated in 20 patients with typical AFL (68.0 +/- 8.8 yr) and some degree of atrioventricular (AV) conduction block. In all patients, atrial intervals displayed oscillations strongly coupled and in phase with respiration (gamma(AA)(2)= 0.97 +/- 0.05, phi(AA) = 0.71 +/- 0.31 rad), corresponding to a paradoxical lengthening of intervals during inspiration. The modulation pattern was frequency independent, with in-phase oscillations and short time delays (0.40 +/- 0.15 s) for respiratory frequencies in the range 0.1-0.4 Hz. Ventricular patterns were affected by AV conduction type. In patients with fixed AV conduction, ventricular intervals displayed oscillations strongly coupled (gamma(RR)(2)= 0.97 +/- 0.03) and in phase with respiration (phi(RR) = 1.08 +/- 0.80 rad). Differently, in patients with variable AV conduction, respiratory oscillations were secondary to Wencheback rhythmicity, resulting in a decreased level of coupling (gamma(RR)(2)= 0.50 +/- 0.21). Simulations with a simplified model of AV conduction showed ventricular patterns to originate from the combination of a respiratory modulated atrial input with the functional properties of the AV node. The paradoxical frequency-independent modulation pattern of atrial interval, the short time delays, and the complexity of

  2. Inter-subject variability in human atrial action potential in sinus rhythm versus chronic atrial fibrillation.

    Directory of Open Access Journals (Sweden)

    Carlos Sánchez

    Full Text Available Human atrial electrophysiology exhibits high inter-subject variability in both sinus rhythm (SR and chronic atrial fibrillation (cAF patients. Variability is however rarely investigated in experimental and theoretical electrophysiological studies, thus hampering the understanding of its underlying causes but also its implications in explaining differences in the response to disease and treatment. In our study, we aim at investigating the ability of populations of human atrial cell models to capture the inter-subject variability in action potential (AP recorded in 363 patients both under SR and cAF conditions.Human AP recordings in atrial trabeculae (n = 469 from SR and cAF patients were used to calibrate populations of computational SR and cAF atrial AP models. Three populations of over 2000 sampled models were generated, based on three different human atrial AP models. Experimental calibration selected populations of AP models yielding AP with morphology and duration in range with experimental recordings. Populations using the three original models can mimic variability in experimental AP in both SR and cAF, with median conductance values in SR for most ionic currents deviating less than 30% from their original peak values. All cAF populations show similar variations in G(K1, G(Kur and G(to, consistent with AF-related remodeling as reported in experiments. In all SR and cAF model populations, inter-subject variability in I(K1 and I(NaK underlies variability in APD90, variability in I(Kur, I(CaL and I(NaK modulates variability in APD50 and combined variability in Ito and I(Kur determines variability in APD20. The large variability in human atrial AP triangulation is mostly determined by I(K1 and either I(NaK or I(NaCa depending on the model.Experimentally-calibrated human atrial AP models populations mimic AP variability in SR and cAF patient recordings, and identify potential ionic determinants of inter-subject variability in human atrial AP

  3. Association of Atrial Fibrillation with Morphological and Electrophysiological Changes of the Atrial Myocardium.

    Science.gov (United States)

    Matějková, Adéla; Šteiner, Ivo

    Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. For long time it was considered as pure functional disorder, but in recent years, there were identified atrial locations, which are involved in the initiation and maintenance of this arrhythmia. These structural changes, so called remodelation, start at electric level and later they affect contractility and morphology. In this study we attempted to find a possible relation between morphological (scarring, amyloidosis, left atrial (LA) enlargement) and electrophysiological (ECG features) changes in patients with AF. We examined grossly and histologically 100 hearts of necropsy patients - 54 with a history of AF and 46 without AF. Premortem ECGs were evaluated. The patients with AF had significantly heavier heart, larger LA, more severely scarred myocardium of the LA and atrial septum, and more severe amyloidosis in both atria. Severity of amyloidosis was higher in LAs vs. right atria (RAs). Distribution of both fibrosis and amyloidosis was irregular. The most affected area was in the LA anterior wall. Patients with a history of AF and with most severe amyloidosis have more often abnormally long P waves. Finding of long P wave may contribute to diagnosis of a hitherto undisclosed atrial fibrillation.

  4. Atrial remodeling and metabolic dysfunction in idiopathic isolated fibrotic atrial cardiomyopathy.

    Science.gov (United States)

    Cui, Chang; Jiang, Xiaohong; Ju, Weizhu; Wang, Jiaxian; Wang, Daowu; Sun, Zheng; Chen, Minglong

    2018-04-26

    Idiopathic isolated fibrotic atrial cardiomyopathy (IIF-ACM) is a novel subtype of cardiomyopathy characterized by atrial fibrosis that does not involve the ventricular myocardium and is associated with significant atrial tachyarrhythmia. The mechanisms underlying its pathogenesis are unknown. Atrium samples were obtained from 3 patients with IIF-ACM via surgical intervention. Control samples were consisted of 3 atrium biopsies from patients with congenital heart disease and normal sinus rhythm, matched for gender, age and basic clinical characteristics. Comparative histology, immunofluorescence staining, electron microscopy and proteomics analyses were carried out to explore the unique pathogenesis of IIF-ACM. IIF-ACM atria displayed disordered myofibrils, profound fibrosis and mitochondrial damages compared to the control atria. Proteomics profiling identified metabolic pathways as the most profound changes in IIF-ACM. Our study suggested that metabolic changes in the atrial myocardium caused mitochondrial oxidative stress and potential cell damage, which further led to atrial fibrosis and myofibril disorganization, the characteristic phenotype of IIF-ACM. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Cardiac ion channels and mechanisms for protection against atrial fibrillation

    DEFF Research Database (Denmark)

    Grunnet, Morten; Bentzen, Bo Hjorth; Sørensen, Ulrik S

    2011-01-01

    Atrial fibrillation (AF) is recognised as the most common sustained cardiac arrhythmia in clinical practice. Ongoing drug development is aiming at obtaining atrial specific effects in order to prevent pro-arrhythmic, devastating ventricular effects. In principle, this is possible due to a differe...... to the recent discovery that Ca(2+)-activated small conductance K(+) channels (SK channels) are important for the repolarisation of atrial action potentials. Finally, an overview of current pharmacological treatment of AF is included....

  6. Extreme variation in the atrial septation of caecilians (Amphibia: Gymnophiona)

    Science.gov (United States)

    de Bakker, Desiderius M; Wilkinson, Mark; Jensen, Bjarke

    2015-01-01

    Caecilians (order Gymnophiona) are elongate, limbless, snake-like amphibians that are the sister-group (closest relatives) of all other recent amphibians (frogs and salamanders). Little is known of their cardiovascular anatomy and physiology, but one nearly century old study suggests that Hypogeophis (family Indotyphlidae), commonly relied upon as a representative caecilian species, has atrial septation in the frontal plane and more than one septum. In contrast, in other vertebrates there generally is one atrial septum in the sagittal plane. We studied the adult heart of Idiocranium (also Indotyphlidae) using immunohistochemistry and confirm that the interatrial septum is close to the frontal plane. Additionally, a parallel right atrial septum divides three-fourths of the right atrial cavity of this species. Idiocranium embryos in the Hill collection reveal that atrial septation initiates in the sagittal plane as in other tetrapods. Late developmental stages, however, see a left-ward shift of visceral organs and a concordant rotation of the atria that reorients the atrial septa towards the frontal plane. The gross anatomies of species from six other caecilian families reveal that (i) the right atrial septum developed early in caecilian evolution (only absent in Rhinatrematidae) and that (ii) rotation of the atria evolved later and its degree varies between families. In most vertebrates a prominent atrial trabeculation associates with the sinuatrial valve, the so-called septum spurium, and the right atrial septum seems homologous to this trabeculation but much more developed. The right atrial septum does not appear to be a consequence of body elongation because it is absent in some caecilians and in snakes. The interatrial septum of caecilians shares multiple characters with the atrial septum of lungfishes, salamanders and the embryonic septum primum of amniotes. In conclusion, atrial septation in caecilians is based on evolutionarily conserved structures but

  7. Atrial Fibrillation Following Surgical Management of Ischemic Heart Disease; One Year, Single Center, Single Surgeon Results

    Directory of Open Access Journals (Sweden)

    Ahmet Barış Durukan

    2012-08-01

    Full Text Available Introduction: Postoperative atrial fibrillation is the most common arrhythmia following bypasssurgery with significant morbidity, mortality and increased healthcare costs. The aim of this studyis to determine the incidence and timing of atrial fibrillation, identify the risk factors coveringpreoperative and intraoperative periods, evaluate rate of return to sinus rhythm by disharge, andexplore the impact on postoperative outcomes in a large group of patients operated in a singlecenter by a single surgeon.Patients and Methods: Between January 2011 and January 2012, 418 patients on preoperativesinus rhythm were operated for ischemic heart disease and associated complications (left ventricleaneurysm repair and ischemic mitral insufficiency in a single center, by a single surgeon.The preoperative, intraoperative and postoperative variables were studied.Results: The mean age of the patients were 61.92 ± 10.05, and 77.5% were male. Atrial fibrillationdeveloped in 68 (16.3% patients. The incidence peaked at second day. Patients with atrialfibrillation were older (p< 0.001. Gender, preoperative comorbidities, ejection fraction, left atrialdiameter, preoperative beta-blocker use, leukocyte count, type of operation and intraoperativevariables did not affect its occurence. Intensive care unit and hospital length of stay were longer(p< 0.05. 95.5% (n= 65 of patients were in normal sinus rhythm at discharge.Conclusion: Postoperative atrial fibrillation is a popular subject with unknowns and controversialresults which may lead to wrong interpretations. We believe that every center has its own risk factors related with the population of that region. Discussion will last, but simple precautions and close monitoring will help to minimizeadverse outcomes.

  8. Hemodynamic forces regulate developmental patterning of atrial conduction.

    Directory of Open Access Journals (Sweden)

    Michael C Bressan

    Full Text Available Anomalous action potential conduction through the atrial chambers of the heart can lead to severe cardiac arrhythmia. To date, however, little is known regarding the mechanisms that pattern proper atrial conduction during development. Here we demonstrate that atrial muscle functionally diversifies into at least two heterogeneous subtypes, thin-walled myocardium and rapidly conducting muscle bundles, during a developmental window just following cardiac looping. During this process, atrial muscle bundles become enriched for the fast conduction markers Cx40 and Nav1.5, similar to the precursors of the fast conduction Purkinje fiber network located within the trabeculae of the ventricles. In contrast to the ventricular trabeculae, however, atrial muscle bundles display an increased proliferation rate when compared to the surrounding myocardium. Interestingly, mechanical loading of the embryonic atrial muscle resulted in an induction of Cx40, Nav1.5 and the cell cycle marker Cyclin D1, while decreasing atrial pressure via in vivo ligation of the vitelline blood vessels results in decreased atrial conduction velocity. Taken together, these data establish a novel model for atrial conduction patterning, whereby hemodynamic stretch coordinately induces proliferation and fast conduction marker expression, which in turn promotes the formation of large diameter muscle bundles to serve as preferential routes of conduction.

  9. Entropy measurements in paroxysmal and persistent atrial fibrillation

    International Nuclear Information System (INIS)

    Cervigón, R; Moreno, J; Pérez-Villacastín, J; Reilly, R B; Millet, J; Castells, F

    2010-01-01

    Recent studies on atrial fibrillation (AF) have identified different activation patterns in paroxysmal and persistent AF. In this study, bipolar intra-atrial registers from 28 patients (14 paroxysmal AF and 14 persistent AF) were analyzed in order to find out regional differences in the organization in both types of arrhythmias. The organization of atrial electrical activity was assessed in terms of nonlinear parameters, such as entropy measurements. Results showed differences between the atrial chambers with a higher disorganization in the left atrium in paroxysmal AF patients and a more homogenous behavior along the atria in persistent AF patients

  10. Fractional Vector Calculus and Fractional Special Function

    OpenAIRE

    Li, Ming-Fan; Ren, Ji-Rong; Zhu, Tao

    2010-01-01

    Fractional vector calculus is discussed in the spherical coordinate framework. A variation of the Legendre equation and fractional Bessel equation are solved by series expansion and numerically. Finally, we generalize the hypergeometric functions.

  11. Pathogenic Mechanisms of Atrial Fibrillation in Obesity

    Directory of Open Access Journals (Sweden)

    O. M. Drapkina

    2016-01-01

    Full Text Available Atrial fibrillation (AF is one of the most common arrhythmias. It reduces quality of life and its duration due to thromboembolic complications. Obesity contributes to the structural and electrical remodeling of atrial myocardium. This leads to occurrence of ectopic foci in the mouths of the pulmonary veins and the disruption of normal electrical conduction in the atria. Systemic inflammation, myocardial fibrosis, cardiomyocyte overload by Na+ and Ca2+ ions, accumulation in the cells of unoxidized metabolic products, imbalance of the autonomic regulation are considered as the main mechanisms of arrhythmogenic substrate formation. Hypertension, insulin resistance, and obstructive sleep apnea, associated with obesity, increase the risk of development and progression of the arrhythmia. Study of pathogenetic mechanisms of AF in obesity is necessary to develop new strategies for its prevention and the creation of more effective methods of treatment of these patients.

  12. [Atrial fibrillation concomitant with valvular heart disease].

    Science.gov (United States)

    Ishii, Yosuke

    2013-01-01

    Patients with valvular heart disease frequently have atrial fibrillation(AF) due to elevated pressure and dilatation of the left and right atria and pulmonary veins. Guidelines for valvular heart disease and AF recommend that surgical treatment for the valvular heart disease should be performed concomitantly with AF surgery. The Full-Maze procedure has evolved into the gold standard of treatment for medically refractory AF. In addition to the pulmonary vein isolation, the right and left atrial incisions of the Full-Maze procedure are designed to block potential macroreentrant pathways. According to the mechanisms of AF with valvular heart disease, the Full-Maze procedure is more effective for the patients than the pulmonary vein isolation alone.

  13. Atrial Function in Patients with Breast Cancer After Treatment with Anthracyclines.

    Science.gov (United States)

    Yaylali, Yalin Tolga; Saricopur, Ahmet; Yurtdas, Mustafa; Senol, Hande; Gokoz-Dogu, Gamze

    2016-11-01

    Atrial electromechanical delay (EMD) is used to predict atrial fibrillation, measured by echocardiography. The aim of this study was to assess atrial EMD and mechanical function after anthracycline-containing chemotherapy. Fifty-three patients with breast cancer (48 ± 8 years old) who received 240 mg/m2of Adriamycin, 2400 mg/m2 of cyclophosphamide, and 960 mg/m2 of paclitaxel were included in this retrospective study, as were 42 healthy subjects (47 ± 9 years old). Echocardiographic measurements were performed 11 ± 7 months (median 9 months) after treatment with anthracyclines. Left intra-atrial EMD (11.4 ± 6.0 vs. 8.1 ± 4.9, p=0.008) and inter-atrial EMD (19.7 ± 7.4 vs. 14.7 ± 6.5, p=0.001) were prolonged; LA passive emptying volume and fraction were decreased (p=0.0001 and p=0.0001); LA active emptying volume and fraction were increased (p=0.0001 and p=0.0001); Mitral A velocity (0.8 ± 0.2 vs. 0.6 ± 0.2, p=0.0001) and mitral E-wave deceleration time (201.2 ± 35.6 vs. 163.7 ± 21.8, p=0.0001) were increased; Mitral E/A ratio (1.0 ± 0.3 vs. 1.3 ± 0.3, p=0.0001) and mitral Em (0.09 ± 0.03 vs. 0.11 ± 0.03, p=0.001) were decreased; Mitral Am (0.11 ± 0.02 vs. 0.09 ± 0.02, p=0.0001) and mitral E/Em ratio (8.8 ± 3.2 vs. 7.6 ± 2.6, p=0.017) were increased in the patients. In patients with breast cancer after anthracycline therapy: Left intra-atrial, inter-atrial electromechanical intervals were prolonged. Diastolic function was impaired. Impaired left ventricular relaxation and left atrial electrical conduction could be contributing to the development of atrial arrhythmias. Atraso eletromecânico atrial (AEA) é utilizado para prever fibrilação atrial, medido pela ecocardiografia. O propósito deste estudo era verificar o AEA e a função mecânica após quimioterapia com antraciclinas. Cinquenta e três pacientes com câncer de mama (48 ± 8 anos) que receberam 240 mg/m2 de adriamicina, 2400 mg/m2 de ciclofosfamida, e 960 mg/m2 de paclitaxel foram

  14. Endurance Sport Practice and Atrial Fibrillation

    OpenAIRE

    Calvo, Naiara; Mont, Lluis

    2010-01-01

    Atrial fibrillation (AF) is the most common cardiac rhythm disorder in clinical practice, with an estimated prevalence of 0.4% to 1% in the general population, increasing with age to 8% in those older than 80 years. The recognized risk factors for developing AF include age, hypertension, structural heart disease, diabetes mellitus, and hyperthyroidism. However, the etiology remains unclear in a significant number of patients younger than age 60 in whom no cardiovascular disease or any other k...

  15. Red Wine, Resveratrol and Atrial Fibrillation

    OpenAIRE

    Stephan, Laura Siga; Almeida, Eduardo Dytz; Markoski, Melissa Medeiros; Garavaglia, Juliano; Marcadenti, Aline

    2017-01-01

    Atrial fibrillation (AF) is a common cardiac arrhythmia that is associated with increased risk for cardiovascular disease and overall mortality. Excessive alcohol intake is a well-known risk factor for AF, but this correlation is less clear with light and moderate drinking. Besides, low doses of red wine may acutely prolong repolarization and slow cardiac conduction. Resveratrol, a bioactive polyphenol found in grapes and red wine, has been linked to antiarrhythmic properties and may act as a...

  16. Acute atrial fibrillation during dengue hemorrhagic fever

    Directory of Open Access Journals (Sweden)

    Henrique Horta Veloso

    Full Text Available Dengue fever is a viral infection transmitted by the mosquito, Aedes aegypti. Cardiac rhythm disorders, such as atrioventricular blocks and ventricular ectopic beats, appear during infection and are attributed to viral myocarditis. However, supraventricular arrhythmias have not been reported. We present a case of acute atrial fibrillation, with a rapid ventricular rate, successfully treated with intravenous amiodarone, in a 62-year-old man with dengue hemorrhagic fever, who had no structural heart disease.

  17. Acute atrial fibrillation during dengue hemorrhagic fever

    Directory of Open Access Journals (Sweden)

    Veloso Henrique Horta

    2003-01-01

    Full Text Available Dengue fever is a viral infection transmitted by the mosquito, Aedes aegypti. Cardiac rhythm disorders, such as atrioventricular blocks and ventricular ectopic beats, appear during infection and are attributed to viral myocarditis. However, supraventricular arrhythmias have not been reported. We present a case of acute atrial fibrillation, with a rapid ventricular rate, successfully treated with intravenous amiodarone, in a 62-year-old man with dengue hemorrhagic fever, who had no structural heart disease.

  18. Association Between Left Atrial Compression And Atrial Fibrillation: A Case Presentation And A Short Review Of Literature.

    Science.gov (United States)

    Ahmed, Niloy; Carlos, Morales-Mangual; Moshe, Gunsburg; Yitzhak, Rosen

    2016-01-01

    This case report describes a patient who developed palpitations and chest pain and was found to be in atrial fibrillation, which was likely due to the presence of an extra-cardiac mass. This was compressing the left atrium. The mass was related to small cell carcinoma, which decreased significantly in size after chemotherapy. Resolution of the atrial fibrillation correlated temporally with reduction in the size of the mass and alleviation of the left atrial compression.

  19. Atrial Fibrillation in Eight New World Camelids.

    Science.gov (United States)

    Bozorgmanesh, R; Magdesian, K G; Estell, K E; Stern, J A; Swain, E A; Griffiths, L G

    2016-01-01

    There is limited information on the incidence of clinical signs, concurrent illness and treatment options for atrial fibrillation (AF) in New World Camelids (NWC). Describe clinical signs and outcome of AF in NWC. Eight New World Camelids admitted with AF. A retrospective observational study of camelids diagnosed with AF based on characteristic findings on electrocardiogram (ECG). All animals had an irregularly irregular heart rhythm detected on physical examination and 4 cases had obtunded mentation on admission. Three camelids were diagnosed with AF secondary to oleander intoxication, 3 animals had underlying cardiovascular disease, 1 was diagnosed with lone AF and 1 had AF diagnosed on examination for a urethral obstruction. Five of eight animals survived to discharge and nonsurvivors consisted of animals which died or were euthanized as a result of cardiovascular disease (2/8) or extra-cardiac disease unrelated to the AF (1/8). Atrial fibrillation occurs in NWC in association with cardiovascular disease, extra-cardiac disease or as lone AF. Amiodarone and transthoracic cardioversion were attempted in one llama with lone AF, but were unsuccessful. Atrial fibrillation was recorded in 0.1% of admissions. Copyright © 2015 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  20. 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. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Cardiology.

  1. Atrial fibrillation pearls and perils of management.

    Science.gov (United States)

    Kudenchuk, P J

    1996-01-01

    Atrial fibrillation, a common arrhythmia, is responsible for considerable cardiovascular morbidity. Its management demands more than antiarrhythmic therapy alone, but must address the causes and consequences of the arrhythmia. Although remediable causes are infrequently found, a thorough search for associated heart disease or its risk factors results in better-informed patient management. Controlling the ventricular response and protecting from thromboembolic complications are important initial goals of therapy and may include the administration of aspirin in younger, low-risk patients. Older patients and those with risk factors for systemic embolism are not adequately protected from stroke complications by aspirin therapy alone. It remains controversial whether all high-risk patients should receive warfarin and at what intensity. Whether and how sinus rhythm should be restored and maintained poses the greatest therapeutic controversy for atrial fibrillation. The mortal risk of antiarrhythmic therapy is substantially greater in patients with evidence of heart failure. In such persons, the risks and benefits of maintaining normal sinus rhythm with antiarrhythmic medications should be weighted carefully. A definitive cure for atrial fibrillation remains elusive, but promising surgical and catheter ablation therapies are being developed. PMID:8686300

  2. The mechanisms of atrial fibrillation in hyperthyroidism

    Directory of Open Access Journals (Sweden)

    Bielecka-Dabrowa Agata

    2009-04-01

    Full Text Available Abstract Atrial fibrillation (AF is a complex condition with several possible contributing factors. The rapid and irregular heartbeat produced by AF increases the risk of blood clot formation inside the heart. These clots may eventually become dislodged, causing embolism, stroke and other disorders. AF occurs in up to 15% of patients with hyperthyroidism compared to 4% of people in the general population and is more common in men and in patients with triiodothyronine (T3 toxicosis. The incidence of AF increases with advancing age. Also, subclinical hyperthyroidism is a risk factor associated with a 3-fold increase in development of AF. Thyrotoxicosis exerts marked influences on electrical impulse generation (chronotropic effect and conduction (dromotropic effect. Several potential mechanisms could be invoked for the effect of thyroid hormones on AF risk, including elevation of left atrial pressure secondary to increased left ventricular mass and impaired ventricular relaxation, ischemia resulting from increased resting heart rate, and increased atrial eopic activity. Reentry has been postulated as one of the main mechanisms leading to AF. AF is more likely if effective refractory periods are short and conduction is slow. Hyperthyroidism is associated with shortening of action potential duration which may also contribute to AF.

  3. Analysis of immune cell populations in atrial myocardium of patients with atrial fibrillation or sinus rhythm.

    Directory of Open Access Journals (Sweden)

    Natalia Smorodinova

    Full Text Available Atrial fibrillation (AF is the most common arrhythmia and despite obvious clinical importance remains its pathogenesis only partially explained. A relation between inflammation and AF has been suggested by findings of increased inflammatory markers in AF patients.The goal of this study was to characterize morphologically and functionally CD45-positive inflammatory cell populations in atrial myocardium of patients with AF as compared to sinus rhythm (SR.We examined 46 subjects (19 with AF, and 27 in SR undergoing coronary bypass or valve surgery. Peroperative bioptic samples of the left and the right atrial tissue were examined using immunohistochemistry.The number of CD3+ T-lymphocytes and CD68-KP1+ cells were elevated in the left atrial myocardium of patients with AF compared to those in SR. Immune cell infiltration of LA was related to the rhythm, but not to age, body size, LA size, mitral regurgitation grade, type of surgery, systemic markers of inflammation or presence of diabetes or hypertension. Most of CD68-KP1+ cells corresponded to dendritic cell population based on their morphology and immunoreactivity for DC-SIGN. The numbers of mast cells and CD20+ B-lymphocytes did not differ between AF and SR patients. No foci of inflammation were detected in any sample.An immunohistochemical analysis of samples from patients undergoing open heart surgery showed moderate and site-specific increase of inflammatory cells in the atrial myocardium of patients with AF compared to those in SR, with prevailing population of monocyte-macrophage lineage. These cells and their cytokine products may play a role in atrial remodeling and AF persistence.

  4. EXAMINATION OF ELECTROPHYSIOLOGICAL PARAMETERS OF THE ATRIUMS IN PATIENTS WITH LONG-TERM PERSISTENT FORM OF ATRIAL FIBRILLATION AND VALVULAR HEART DISEASE

    Directory of Open Access Journals (Sweden)

    A. A. Kulikov

    2017-01-01

    Full Text Available The study objective is to examine electrophysiological parameters of atrial myocardium, characteristics of atrioventricular conduction, and potential factors affecting recurrent atrial fibrillation (AF in patients with persistent and long-term persistent forms of AF prior to the Labirynth IIIB surgery with single-step correction of valvular heart disease.Materials and methods. The study included 100 adults (48 men, 52 women with persistent and long-term persistent forms of AF and different valvular heart diseases. Mean patient age was 59 years. Mean AF duration was 4 years. All patients were prescribed antiarrhythmic therapy but it proved ineffective. In 15 % of patients, restoration of the sinus rhythm was attempted through electrical cardioversion but long-term control of the sinus rhythm wasn’t achieved. All patients were diagnosed with organic pathology of the mitral valve. Also, in 80 % of patients, relative insufficiency of the tricuspid valve was detected. Chronic heart failure functional class per NYHA was III. Size of the left atrium was 5 cm, mean left ventricular ejection fraction was 61 %. All patients underwent electrical cardioversion. After successful restoration of the sinus rhythm, endocardial electrophysiology study (EES of the heart was performed. Then, correction of valvular pathologies and the Labyrinth IIIB surgery were performed. Results. Examination of refractoriness of different parts of the atriums has shown that effective refractory period (ERP of the atrioventricular node was minimal compared to other parts of the atriums. Maximal ERP duration was observed in the upper part of the right atrium. Therefore, in patients with long history of AF, heterogeneity of atrial myocardium ERP duration is observed. In 17 % of patients, atrial vulnerability was detected. The area of atrial vulnerability was always associated with ERP. Its duration in patients with atrial vulnerability was significantly higher.Conclusion. Long

  5. Tratamento cirúrgico da fibrilação atrial crônica com eletrocautério convencional em cirurgia valvar mitral Surgical treatment of chronic atrial fibrillation with conventional electrocautery in mitral valve surgery

    Directory of Open Access Journals (Sweden)

    Jandir Ferreira Gomes Júnior

    2008-09-01

    age of the patients was 59 years, and 60.8% were female. The left atrium mean diameter was 50.3 ± 5.09 mm and the left ventricular ejection fraction was 53.6 ± 11.03%. RESULTS: The mean time of extracorporeal circulation was 52.5 ± 13.3 min; aortic clamping, 35.6 ± 12.9 min; atrial ablation, 3.05 ± 0.16 min. All the patients were free of atrial fibrillation after the procedure; on hospital discharge, 69.5%; at 6 months, 91.3%; at 12 months, 76.4%; at 18 months, and at 24 months, 68.4%. At 12 months, left atrium mean diameter was 42.1 ± 3.5 mm; left ventricular ejection fraction was 59.2 ± 3.48%; In addition, left atrial contraction was present in 68.8% of the patients. CONCLUSION: The surgical treatment of the atrial fibrillation with electrocautery in mitral valve surgery was capable to determine the reversion of this arrhythmia in a significant number of patients during short- and middle-term clinical follow-up without mortality and fewer complications.

  6. Recurrence of pulmonary vein conduction and atrial fibrillation after pulmonary vein isolation for atrial fibrillation

    DEFF Research Database (Denmark)

    Nilsson, Brian; Chen, Xu; Pehrson, Steen

    2006-01-01

    BACKGROUND: Both segmental ostial and circumferential extraostial pulmonary vein (PV) isolation have been proven effective in the treatment of atrial fibrillation (AF). However, the recurrence of AF and PV conduction after the 2 ablation strategies has never been compared in a randomized study...... isolation. Extraostial PV isolation was performed by encircling the paired left and right PVs, respectively, guided by an electroanatomic mapping system. RESULTS: A total of 84% of the patients had recurrent AF after the first PV isolation procedure, showing 72% with AF and 12% with organized left atrial...

  7. Atrial remodelling in atrial fibrillation: CaMKII as a nodal proarrhythmic signal

    Science.gov (United States)

    Mesubi, Olurotimi O.; Anderson, Mark E.

    2016-01-01

    CaMKII is a serine–threonine protein kinase that is abundant in myocardium. Emergent evidence suggests that CaMKII may play an important role in promoting atrial fibrillation (AF) by targeting a diverse array of proteins involved in membrane excitability, cell survival, calcium homeostasis, matrix remodelling, inflammation, and metabolism. Furthermore, CaMKII inhibition appears to protect against AF in animal models and correct proarrhythmic, defective intracellular Ca2+ homeostasis in fibrillating human atrial cells. This review considers current concepts and evidence from animal and human studies on the role of CaMKII in AF. PMID:26762270

  8. Radionuclide analysis of right and left ventricular response to exercise in patients with atrial and ventricular septal defects

    International Nuclear Information System (INIS)

    Peter, C.A.; Bowyer, K.; Jones, R.H.

    1983-01-01

    In patients with ventricular or atrial septal defect, the ventricle which is chronically volume overloaded might not appropriately respond to increased demand for an augmentation in output and thereby might limit total cardiac function. In this study we simultaneously measured right and left ventricular response to exercise in 10 normal individuals, 10 patients with ventricular septal defect (VSD), and 10 patients with atrial septal defect (ASD). The normal subjects increased both right and left ventricular ejection fraction, end-diastolic volume, and stroke volume to achieve a higher cardiac output during exercise. Patients with VSD failed to increase right ventricular ejection fraction, but increased right ventricular end-diastolic volume and stroke volume. Left ventricular end-diastolic volume did not increase in these patients but ejection fraction, stroke volume, and forward left ventricular output achieved during exercise were comparable to the response observed in healthy subjects. In the patients with ASD, no rest-to-exercise change occurred in either right ventricular ejection fraction, end-diastolic volume, or stroke volume. In addition, left ventricular end-diastolic volume failed to increase, and despite an increase in ejection fraction, left ventricular stroke volume remained unchanged from rest to exercise. Therefore, cardiac output was augmented only by the heart rate increase in these patients. Right ventricular function appeared to be the major determinant of total cardiac output during exercise in patients with cardiac septal defects and left-to-right shunt

  9. Histopathologic analysis of atrial tissue in patients with atrial fibrillation: comparison between patients with atrial septal defect and patients with mitral valvular heart disease.

    Science.gov (United States)

    Kwak, Jae Gun; Seo, Jeong-Wook; Oh, Sam Se; Lee, Sang Yun; Ham, Eui Keun; Kim, Woong-Han; Kim, Soo-Jin; Bae, Eun Jung; Lim, Cheoung; Lee, Chang-Ha; Lee, Cheul

    2014-01-01

    Atrial fibrillation (AF) in adult patients with atrial septal defect (ASD) accompanies an enlarged right atrium (RA) with a less enlarged left atrium (LA), which is the opposite situation in patients with AF and mitral valvular disease. This study was to compare the histopathological change in the atrium of patients with AF of two different etiologies: ASD and mitral disease. Twenty-four patients were enrolled. Group 1 included patients with ASD (8), Group 2 included patients with ASD with AF (6), and Group 3 included patients with mitral disease with AF (10). Preoperative atrial volumes were measured. Atrial tissues were obtained during surgical procedures and stained with periodic acid-Schiff, smooth muscle actin, Sirius red, and Masson's trichrome to detect histopathologic changes compatible with AF. The severity of histopathological changes was represented with "positivity" and "strong positivity" after analyzing digitalized images of the staining. We investigated the relationship between the degree of atrial dilatation and severity of histopathological changes according to the groups and tissues. Group 2 and Group 3 patients showed a tendency toward an enlarged RA volume and enlarged LA volume, respectively, compared with each others. However, in the histopathologic analysis, "positivity" and "strong positivity" showed no significant positive correlations with the degree of atrial volume in special staining. A similar degree of histopathologic changes was observed in both atria in patients with AF (Group 2 and 3) regardless of the degree of dilatation of atrial volume and disease entities. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

  10. Systemic right ventricular fibrosis detected by cardiovascular magnetic resonance is associated with clinical outcome, mainly new-onset atrial arrhythmia, in patients after atrial redirection surgery for transposition of the great arteries.

    Science.gov (United States)

    Rydman, Riikka; Gatzoulis, Michael A; Ho, Siew Yen; Ernst, Sabine; Swan, Lorna; Li, Wei; Wong, Tom; Sheppard, Mary; McCarthy, Karen P; Roughton, Michael; Kilner, Philip J; Pennell, Dudley J; Babu-Narayan, Sonya V

    2015-05-01

    We hypothesized that fibrosis detected by late gadolinium enhancement (LGE) cardiovascular magnetic resonance predicts outcomes in patients with transposition of the great arteries post atrial redirection surgery. These patients have a systemic right ventricle (RV) and are at risk of arrhythmia, premature RV failure, and sudden death. Fifty-five patients (aged 27±7 years) underwent LGE cardiovascular magnetic resonance and were followed for a median 7.8 (interquartile range, 3.8-9.6) years in a prospective single-center cohort study. RV LGE was present in 31 (56%) patients. The prespecified composite clinical end point comprised new-onset sustained tachyarrhythmia (atrial/ventricular) or decompensated heart failure admission/transplantation/death. Univariate predictors of the composite end point (n=22 patients; 19 atrial/2 ventricular tachyarrhythmia, 1 death) included RV LGE presence and extent, RV volumes/mass/ejection fraction, right atrial area, peak Vo(2), and age at repair. In bivariate analysis, RV LGE presence was independently associated with the composite end point (hazard ratio, 4.95 [95% confidence interval, 1.60-15.28]; P=0.005), and only percent predicted peak Vo(2) remained significantly associated with cardiac events after controlling for RV LGE (hazard ratio, 0.80 [95% confidence interval, 0.68-0.95]; P=0.009/5%). In 8 of 9 patients with >1 event, atrial tachyarrhythmia, itself a known risk factor for mortality, occurred first. There was agreement between location and extent of RV LGE at in vivo cardiovascular magnetic resonance and histologically documented focal RV fibrosis in an explanted heart. There was RV LGE progression in a different case restudied for clinical indications. Systemic RV LGE is strongly associated with adverse clinical outcome especially arrhythmia in transposition of the great arteries, thus LGE cardiovascular magnetic resonance should be incorporated in risk stratification of these patients. © 2015 American Heart

  11. Atrial Heterogeneity Generates Re-entrant Substrate during Atrial Fibrillation and Anti-arrhythmic Drug Action: Mechanistic Insights from Canine Atrial Models

    Science.gov (United States)

    Varela, Marta; Hancox, Jules C.; Aslanidi, Oleg V.

    2016-01-01

    Anti-arrhythmic drug therapy is a frontline treatment for atrial fibrillation (AF), but its success rates are highly variable. This is due to incomplete understanding of the mechanisms of action of specific drugs on the atrial substrate at different stages of AF progression. We aimed to elucidate the role of cellular, tissue and organ level atrial heterogeneities in the generation of a re-entrant substrate during AF progression, and their modulation by the acute action of selected anti-arrhythmic drugs. To explore the complex cell-to-organ mechanisms, a detailed biophysical models of the entire 3D canine atria was developed. The model incorporated atrial geometry and fibre orientation from high-resolution micro-computed tomography, region-specific atrial cell electrophysiology and the effects of progressive AF-induced remodelling. The actions of multi-channel class III anti-arrhythmic agents vernakalant and amiodarone were introduced in the model by inhibiting appropriate ionic channel currents according to experimentally reported concentration-response relationships. AF was initiated by applied ectopic pacing in the pulmonary veins, which led to the generation of localized sustained re-entrant waves (rotors), followed by progressive wave breakdown and rotor multiplication in both atria. The simulated AF scenarios were in agreement with observations in canine models and patients. The 3D atrial simulations revealed that a re-entrant substrate was typically provided by tissue regions of high heterogeneity of action potential duration (APD). Amiodarone increased atrial APD and reduced APD heterogeneity and was more effective in terminating AF than vernakalant, which increased both APD and APD dispersion. In summary, the initiation and sustenance of rotors in AF is linked to atrial APD heterogeneity and APD reduction due to progressive remodelling. Our results suggest that anti-arrhythmic strategies that increase atrial APD without increasing its dispersion are

  12. Evaluation of left atrial function by multidetector computed tomography before left atrial radiofrequency-catheter ablation: Comparison of a manual and automated 3D volume segmentation method

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Florian, E-mail: florian.wolf@meduniwien.ac.a [Department of Radiology, Medical University of Vienna, Vienna (Austria); Ourednicek, Petr [Philips Medical Systems, Prague (Czech Republic); Loewe, Christian [Department of Radiology, Medical University of Vienna, Vienna (Austria); Richter, Bernhard; Goessinger, Heinz David; Gwechenberger, Marianne [Department of Cardiology, Medical University of Vienna, Vienna (Austria); Plank, Christina; Schernthaner, Ruediger Egbert; Toepker, Michael; Lammer, Johannes [Department of Radiology, Medical University of Vienna, Vienna (Austria); Feuchtner, Gudrun M. [Department of Radiology, Innsbruck Medical University, Innsbruck (Austria); Institute of Diagnostic Radiology, University Hospital Zurich (Switzerland)

    2010-08-15

    Introduction: The purpose of this study was to compare a manual and automated 3D volume segmentation tool for evaluation of left atrial (LA) function by 64-slice multidetector-CT (MDCT). Methods and materials: In 33 patients with paroxysmal atrial fibrillation a MDCT scan was performed before radiofrequency-catheter ablation. Atrial function (minimal volume (LAmin), maximal volume (LAmax), stroke volume (SV), ejection fraction (EF)) was evaluated by two readers using a manual and an automatic tool and measurement time was evaluated. Results: Automated LA volume segmentation failed in one patient due to low LA enhancement (103HU). Mean LAmax, LAmin, SV and EF were 127.7 ml, 93 ml, 34.7 ml, 27.1% by the automated, and 122.7 ml, 89.9 ml, 32.8 ml, 26.3% by the manual method with no significant difference (p > 0.05) and high Pearsons correlation coefficients (r = 0.94, r = 0.94, r = 0.82 and r = 0.85, p < 0.0001), respectively. The automated method was significantly faster (p < 0.001). Interobserver variability was low for both methods with Pearson's correlation coefficients between 0.98 and 0.99 (p < 0.0001). Conclusions: Evaluation of LA volume and function with 64-slice MDCT is feasible with a very low interobserver variability. The automatic method is as accurate as the manual method but significantly less time consuming permitting a routine use in clinical practice before RF-catheter ablation.

  13. Measurement of ventricular function by ECG gating during atrial fibrillation

    International Nuclear Information System (INIS)

    Bacharach, S.L.; Green, M.V.; Bonow, R.O.; Findley, S.L.; Ostrow, H.G.; Johnston, G.S.

    1981-01-01

    The assumptions necessary to perform ECG-gated cardiac studies are seemingly not valid for patients in atrial fibrillation (AF). To evaluate the effect of AF on equilibrium gated scintigraphy, beat-by-beat measurements of left-ventricular function were made on seven subjects in AF (mean heart rate 64 bpm), using a high-efficiency nonimaging detector. The parameters evaluated were ejection fraction (EF), time to end-systole (TES), peak rates of ejection and filling (PER,PFR), and their times of occurrence (TPER, TPFR). By averaging together single-beat values of EF, PER, etc., it was possible to determine the true mean values of these parameters. The single-beam mean values were compared with the corresponding parameters calculated from one ECG-gated time-activity curve (TAC) obtained by superimposing all the single-beat TACs irrespective of their length. For this population with slow heart rates, we find that the values for EF, etc., produced from ECG-gated time-activity curves, are very similar to those obtained from the single-beat data. Thus use of ECG gating at low heart rates may allow reliable estimation of average cardiac function even in subjects with AF

  14. Left ventricular filling under elevated left atrial pressure

    Science.gov (United States)

    Gaddam, Manikantam; Samaee, Milad; Santhanakrishnan, Arvind

    2017-11-01

    Left atrial pressure (LAP) is elevated in diastolic dysfunction, where left ventricular (LV) filling is impaired due to increase in ventricular stiffness. The impact of increasing LAP and LV stiffness on intraventricular filling hemodynamics remains unclear. We conducted particle image velocimetry and hemodynamics measurements in a left heart simulator (LHS) under increasing LAP and LV stiffness at a heart rate of 70 bpm. The LHS consisted of a flexible-walled LV physical model fitted within a fluid-filled chamber. LV wall motion was generated by a piston pump that imparted pressure fluctuations in the chamber. Resistance and compliance elements in the flow loop were adjusted to obtain bulk physiological hemodynamics in the least stiff LV model. Two LV models of increasing stiffness were subsequently tested under unchanged loop settings. LAP was varied between 5-20 mm Hg for each LV model, by adjusting fluid level in a reservoir upstream of the LV. For constant LV stiffness, increasing LAP lowered cardiac output (CO), while ejection fraction (EF) and E/A ratio were increased. For constant LAP, increasing LV stiffness lowered CO and EF, and increased E/A ratio. The implications of these altered hemodynamics on intraventricular filling vortex characteristics will be presented.

  15. Atrial Fibrillation in Embolic Stroke: Anticoagulant Therapy at UNTH ...

    African Journals Online (AJOL)

    Objective: The decision to commence anticoagulation in a patient with embolic stroke and atrial fibrillation (AF) is often a difficult one for many clinicians. The result can have significant impact on the patient. This study was therefore undertaken to review the use of anticoagulation in embolic stroke in the setting of atrial ...

  16. Dronedarone in high-risk permanent atrial fibrillation

    DEFF Research Database (Denmark)

    Connolly, Stuart J; Camm, A John; Halperin, Jonathan L

    2011-01-01

    Dronedarone restores sinus rhythm and reduces hospitalization or death in intermittent atrial fibrillation. It also lowers heart rate and blood pressure and has antiadrenergic and potential ventricular antiarrhythmic effects. We hypothesized that dronedarone would reduce major vascular events...... in high-risk permanent atrial fibrillation....

  17. The safety of flecainide treatment of atrial fibrillation

    DEFF Research Database (Denmark)

    Almroth, H; Andersson, Torben Bech; Fengsrud, E

    2011-01-01

    To assess the safety of long-term treatment with flecainide in patients with atrial fibrillation (AF), particularly with regard to sudden cardiac death (SCD) and proarrhythmic events.......To assess the safety of long-term treatment with flecainide in patients with atrial fibrillation (AF), particularly with regard to sudden cardiac death (SCD) and proarrhythmic events....

  18. Visualization of atrial myocardium with thallium-201: case report

    International Nuclear Information System (INIS)

    Cowley, M.J.; Coghlan, H.C.; Logic, J.R.

    1977-01-01

    An adult patient evaluated for cyanotic congenital heart disease was found to have pulmonary atresia with intact ventricular septum, hypoplastic right ventricle, and right atrial enlargement. Thallium-201 myocardial imaging before surgical correction showed thallium activity in the right atrium. Following the establishment of a conduit from the right atrium to pulmonary artery, the right-atrial thallium uptake was even more prominent

  19. Dabigatran versus warfarin in patients with atrial fibrillation

    NARCIS (Netherlands)

    Connolly, Stuart J.; Ezekowitz, Michael D.; Yusuf, Salim; Eikelboom, John; Oldgren, Jonas; Parekh, Amit; Pogue, Janice; Reilly, Paul A.; Themeles, Ellison; Varrone, Jeanne; Wang, Susan; Alings, Marco; Xavier, Denis; Zhu, Jun; Diaz, Rafael; Lewis, Basil S.; Darius, Harald; Diener, Hans-Christoph; Joyner, Campbell D.; Wallentin, Lars; Connolly, S. J.; Ezekowitz, M. D.; Yusuf, S.; Eikelboom, J.; Oldgren, J.; Parekh, A.; Reilly, P. A.; Themeles, E.; Varrone, J.; Wang, S.; Palmcrantz-Graf, E.; Haehl, M.; Wallentin, L.; Alings, A. M. W.; Amerena, J. V.; Avezum, A.; Baumgartner, I.; Brugada, J.; Budaj, A.; Caicedo, V.; Ceremuzynski, L.; Chen, J. H.; Commerford, P. J.; Dans, A. L.; Darius, H.; Di Pasquale, G.; Diaz, R.; Erol, C.; Ferreira, J.; Flaker, G. C.; Flather, M. D.; Franzosi, M. G.; Gamboa, R.; Golitsyn, S. P.; Gonzalez Hermosillo, J. A.; Halon, D.; Heidbuchel, H.; Hohnloser, S. H.; Hori, M.; Huber, K.; Jansky, P.; Kamensky, G.; Keltai, M.; Kim, S.; Lau, C. P.; Le Heuzey, J. Y. F.; Lewis, B. S.; Liu, L. S.; Nanas, J.; Razali, O.; Pais, P. S.; Parkhomenko, A. N.; Pedersen, K. E.; Piegas, L. S.; Raev, D.; Simmers, T. A.; Smith, P. J.; Talajic, M.; Tan, R. S.; Tanomsup, S.; Toivonen, L.; Vinereanu, D.; Xavier, D.; Zhu, J.; Diener, H. C.; Joyner, C. D.; Diehl, A.; Ford, G.; Robinson, M.; Silva, J.; Sleight, P.; Wyse, D. G.; Collier, J.; de Mets, D.; Hirsh, J.; Lesaffre, E.; Ryden, L.; Sandercock, P.; Anastasiou-Nana, M. I.; Andersen, G.; Annex, B. H.; Atra, M.; Bornstein, N. M.; Boysen, G.; Brouwers, P. J. A. M.; Buerke, M.; Burrell, L. M.; Chan, Y. K.; Chen, W. H.; Cheung, R. T. F.; Divakaramenon, S.; Donnan, G. A.; Duray, G. Z.; Dvorakova, H.; Fiedler, J.; Gardinale, E.; Gates, P. C.; Goshev, E. G.; Goto, S.; Gross, B.; Guimaraes, H. P.; Gulkevych, O.; Haberl, R. L.; Hankey, G.; Hartikainen, J.; Healey, J.; Iliesiu, A. M.; Irkin, O.; Jaxa-Chamiec, T.; Jolly, S.; Kaste, K. A. M.; Kies, B.; Kostov, K. D.; Kristensen, K. S.; Labovitz, A. J.; Lassila, R. P. T.; Lee, K. L. F.; Lutay, Y. M.; Magloire, P.; Mak, K. H.; Meijer, A.; Mihov, L.; Morillo, C. A.; Morillo, L. E.; Nair, G. M.; Norrving, B.; Ntalianis, A.; Ntsekhe, M.; Olah, L.; Pasco, P. M. D.; Peeters, A.; Perovic, V.; Petrov, I.; Pizzolato, G.; Rafti, F.; Rey, N. R.; Ribas, S.; Rokoss, M.; Sarembock, I. J.; Sheth, T.; Shuaib, A.; Sitkei, E.; Sorokin, E.; Srámek, M.; Strozynska, E.; Tanne, D.; Thijs, V. N. S.; Tomek, A.; Turazza, F.; Vanhooren, G.; Vizel, S. A.; Vos, J.; Wahlgren, N.; Weachter, R.; Zaborska, B.; Zaborski, J.; Zimlichman, R.; Cong, J.; Fendt, K.; Muldoon, S.; Bajkor, S.; Grinvalds, A.; Malvaso, M.; Pogue, J.; Simek, K.; Yang, S.; Alzogaray, M. F.; Bono, J. O.; Caccavo, A.; Cartasegna, L.; Casali, W. P.; Cuello, J. L.; Cuneo, C. A.; Elizari, M. V.; Fernandez, A. A.; Ferrari, A. E.; Gabito, A. J.; Goicoechea, R. F.; Gorosito, V. M.; Hirschson, A.; Hominal, M. A.; Hrabar, A. D.; Liberman, A.; Mackinnon, I. J.; Manzano, R. D.; Muratore, C. A.; Nemi, S. A.; Rodriguez, M. A.; Sanchez, A. S.; Secchi, J.; Vogel, D. R.; Colquhoun, D. M.; Crimmins, D. S.; Dart, A. M.; Davis, S. M.; Hand, P. J.; Kubler, P. A.; Lehman, R. G.; McBain, G.; Morrison, H. C.; New, G.; Singh, B. B.; Spence, C. Z.; Waites, J. H.; Auer, J.; Doweik, L.; Freihoff, F.; Gaul, G.; Gazo, F.; Geiger, H.; Giacomini, G.; Huber, G. W.; Jukic, I.; Lamm, G.; Niessner, H.; Podczeck, A.; Schuh, J.; Siostrzonek, P.; Steger, C.; Vogel, B.; Watzak, R.; Weber, H. S.; Weihs, W.; Blankoff, I.; Boland, J. L.; Brike, C.; Carlier, M.; Cools, F.; de Meester, A.; de Raedt, H. J.; de Wolf, L.; Dhooghe, G. M.; Dilling-Boer, D.; Elshot, S. R.; Fasseaux, S.; Goethals, M.; Goethals, P.; Gurne, O.; Hellemans, S.; Ivan, B.; Jottrand, M.; Kersschot, I.; Lecoq, E.; Marcovitch, O.; Melon, D.; Miljoen, H.; Missault, L.; Pierard, L. A.; Provenier, F.; Rousseau, M. F.; Stockman, D.; Tran-Ngoc, E.; van Mieghem, W.; Vandekerckhove, Y.; Vandervoort, P.; Verrostte, J.; Vijgen, J.; Armaganijan, D.; Braga, C.; Braga, J. C. F.; Cipullo, R.; Cunha, C. L. P.; de Paola, A.; Delmonaco, M. I.; Guimaraes, F. V.; Herek, L.; Kerr Saraiva, J. F.; Maia, L. N.; Lorga, A. M.; Lorga-Filho, A. M.; Marino, R. L.; Melo, C. S.; Mouco, O. M.; Pereira, V. C.; Precoma, D. B.; Rabelo, W.; Rassi, S.; Rossi, P. R.; Rossi Neto, J. M.; Silva, F. M.; Vidotti, M. H.; Zimmermann, S. L.; Anev, E. D.; Balabanov, T. A.; Baldjiev, E. S.; Bogusheva, E. S.; Chaneva, M. A.; Filibev, I. G.; Gotcheva, N. N.; Goudev, A. R.; Gruev, I. T.; Guenova, D. T.; Kamenova, Z. A.; Manov, E. I.; Panov, I. A.; Parvanova, Z. I.; Pehlivanova, M. B.; Penchev, P. T.; Penkov, N. Y.; Radoslavov, A. L.; Ramshev, K. N.; Runev, N. M.; Sindzhielieva, M. N.; Spirova, D. A.; Tsanova, V. M.; Tzekova, M. L.; Yaramov, G. K.; Aggarwal, R.; Bakbak, A. I.; Bayly, K.; Berlingieri, J. C.; Blackburn, K.; Bobbie, C.; Booth, A. W.; Borts, D.; Bose, S.; Boucher, P.; Brown, K.; Burstein, J. M.; Butt, J. C.; Carlson, B. D.; Chetty, R.; Chiasson, J. D.; Constance, C.; Costi, P.; Coutu, B.; Deneufbourg, I.; Dion, D.; Dorian, P.; Douketis, J. D.; Farukh, S.; Filipchuk, N. G.; Fox, B. A.; Fox, H. I.; Gailey, C. B.; Gauthier, M.; Glanz, A.; Green, M. S.; Habot, J.; Hink, H.; Kearon, C.; Kouz, S.; Lai, C.; Lai, K.; Lalani, A. V.; Lam, A. S.; Lapointe, L. A.; Leather, R. A.; Ma, P. T. S.; MacKay, E.; Mangat, I.; Mansour, S.; Melton, E.; Mitchell, L. B.; Morris, A. L.; Nisker, W. A.; O'Donnell, M. J.; O'Hara, G.; Omichinski, L. M.; Pandey, A. S.; Parkash, R.; Pesant, Y.; Pilon, C.; Pistawka, K. J.; Powell, C. N.; Price, J. B.; Prieur, S.; Rebane, T. M.; Ricci, A. J.; Roberge, J.; Roy, M.; Sapp, J. L.; Savard, D.; Schulman, S.; Sehl, M. J.; Sestier, F.; Shandera, R.; Shu, D.; Sterns, L. D.; St-Hilaire, R.; Syan, G. S.; Talbot, P.; Teitelbaum, I.; Tytus, R. H.; Winkler, L.; Zadra, R.; Zidel, B. S.; Bai, X. J.; Gao, W.; Gao, X.; Guan, D. M.; He, Z. S.; Hua, Q.; Li, H.; Li, L.; Li, W. M.; Lu, G. P.; Lv, S.; Meng, K.; Niu, H. Y.; Qi, D. G.; Qi, S. Y.; Qian, F.; Sun, N. L.; Wang, H. Y.; Wang, N. F.; Yang, Y. M.; Zeng, H.; Zhang, F.; Zhang, F. R.; Zhang, L.; Bohorquez, R.; Rosas, J. F.; Saent, L.; Vacca, M.; Velasco, V. M.; Belohlavek, J.; Cernohous, M.; Choura, M.; Dedek, V.; Filipensky, B.; Hemzsky, L.; Karel, I.; Kopeckova, I.; Kovarova, K.; Labrova, R.; Madr, T.; Poklopova, Z.; Rucka, D.; Simon, J.; Skalicka, H.; Smidova, M.; Spinar, J.; Dodt, K. K.; Egstrup, K.; Friberg, J.; Haar, D.; Husted, S.; Jensen, G. V.; Joensen, A. M.; Klarlund, K. K.; Lind Rasmussen, S.; Melchior, T. M.; Olsen, M. E.; Poulsen, M. K.; Ralfkiaer, N.; Rasmussen, L. H.; Skagen, K.; Airaksinen, K. E.; Huikuri, H. V.; Hussi, E. J.; Kettunen, P.; Mänttäri, M.; Melin, J. H.; Mikkelsson, J.; Peuhkurinen, K.; Virtanen, V. K.; Ylitalo, A.; Agraou, B.; Boucher, L.; Bouvier, J. M.; Boye, A.; Boye, B.; Decoulx, E. M.; Defaye, P.; Delay, M.; Desrues, H.; Gacem, K.; Igigabel, P.; Jacon, P.; Leparree, S.; Magnani, C.; Martelet, M.; Movallem, J.; Olive, T.; Poulard, J. E.; Tiam, B.; Appel, K. F.; Appel, S.; Bansemir, L.; Borggrefe, M.; Brachmann, J.; Bulut-Streich, N.; Busch, K.; Dempfle, C. E. H.; Desaga, M.; Desaga, V.; Dormann, A.; Fechner, I.; Genth-Zotz, S.; Haberbosch, W. G.; Harenberg, J.; Haverkamp, W. L.; Henzgen, R.; Heuer, H.; Horacek, T.; Huttner, H. B.; Janssens, U.; Jantke, H. J.; Klauss, V.; Koudonas, D.; Kreuzer, J.; Kuckuck, H.; Maselli, A.; Müegge, A.; Munzel, T. F.; Nitsche, K.; Nledegjen, A.; Parwani, A.; Pluemer-Schmidt, M.; Pollock, B. W.; Salbach, B. I.; Salbach, P. B.; Schaufele, T.; Schoels, W.; Schwab, S.; Siegmund, U.; Veltkamp, R.; Von Hodenberg, E.; Weber, R.; Zechmeister, M.; Anastasopoulous, A. A.; Foulidis, V. O.; Kaldara, E.; Karamitsos, K.; Karantzis, J.; Kirpizidis, H.; Kokkinakis, C.; Krommydas, A.; Lappas, C.; Lappas, G. I.; Manolis, A.; Manolis, A. S.; Orfanidis, Z.; Papamichalis, M.; Peltekis, L.; Savvas, S.; Skoumpourdis, E. A.; Stakos, D. A.; Styliadis, I.; Triposkiadis, F.; Tsounis, D.; Tziakas, D. N.; Zafiridis, T.; Zarifis, J. H.; Chan, G. C. P.; Chan, W. K.; Chan, W. S.; Lau, C. L.; Tse, H. F.; Tsui, P. T.; Yu, C. M.; Yue, C. S.; Fugedi, K.; Garai, B.; Jánosi, A.; Kadar, A.; Karpati, P.; Keltai, K.; Kosa, I.; Kovacs, I.; Laszlo, Z.; Mezei, L.; Rapi, J.; Regos, L. I.; Szakal, I.; Szigyarto, I.; Toth, K.; Zsa'ry, A.; Agarwal, D. K.; Aggarwal, R. K.; Arulvenkatesh, R.; Bharani, A.; Bhuvaneswaran, J. S.; Byrapaneni, R. B.; Chandwani, P.; Chopra, S.; Desai, N.; Deshpande, V.; Golla, N. P.; Gupta, J. B.; Haridas, K. K.; Hiremath, J.; Jain, A. S.; Jain, M.; Jhala, D. A.; Joseph, J.; Kaila, M.; Kannaiyan, A.; Kumar, S.; Kuruvila, P.; Mahorkar, V. K.; Metha, A.; Naik, A. M.; Narayanan, S.; Panwar, R. B.; Reddy, C.; Sawhney, J. P. S.; Shah, S. M.; Sharma, S.; Shetty, G. S.; Sinha, N.; Sontakke, N. N.; Srinivas, A.; Trivedi, M. R.; Vadagenalli, P. S.; Vijayakumar, M.; Ben-Aharon, Y.; Benhorin, J.; Bogomolny, N.; Botwin-Shimko, S.; Bova, I.; Brenner, B.; Burstein, M.; Butnaru, A.; Caspi, A.; Danenberg, H. D.; Dayan, M.; Eldar, M.; Elian, D.; Elias, M.; Elis, A.; Esanu, G.; Genin, I.; Goldstein, L. H.; Grossman, E.; Hamoud, S.; Hayek, T.; Ilani, N.; Ilia, R.; Klainman, E. I.; Leibowitz, A.; Leibowitz, D.; Levin, I.; Lishner, M.; Lotan, C.; Mahagney, A.; Marmor, A.; Motro, M.; Peres, D.; Plaev, T.; Reisen, L. H.; Rogowski, O.; Schwammenthal, E.; Schwammenthal, Y.; Shechter, M.; Shochat, M.; Shotan, A.; Strasberg, B.; Sucher, E.; Telman, G.; Turgeman, Y.; Tzoran, I.; Weiss, A. T.; Weitsman, T.; Weller, B.; Wexler, D. H.; Wolff, R.; Yarnitsky, D.; Zeltser, D.; Argiolas, G.; Arteni, F.; Barbiero, M.; Bazzucco, R.; Bernardi, D.; Bianconi, L.; Bicego, D.; Brandini, R.; Bresciani, B.; Busoni, F.; Carbonieri, E.; Carini, M.; Catalano, A.; Cavallini, C.; D'Angelo, G.; de Caterina, R.; Di Niro, M.; Filigheddu, F.; Fraticelli, A.; Marconi, R.; Mennuni, M.; Moretti, L.; Mos, L.; Pancaldi, L. G.; Pirelli, S.; Renda, G.; Santini, M.; Tavarozzi, I.; Terrosu, P.; Uneddu, F.; Viccione, M.; Zanini, R.; Zingarini, G.; Aoyagi, T.; Eguma, H.; Fujii, K.; Fukuchi, M.; Fukunami, M.; Furukawa, Y.; Furuya, J.; Haneda, K.; Hara, S.; Hiroe, M.; Iesaka, Y.; Iijima, T.; Ishibashi, Y.; Iwade, K.; Kajiya, T.; Kakinoki, S.; Kamakura, S.; Katayama, Y.; Kihara, Y.; Kimura, K.; Kobayashi, S.; Kono, K.; Koretsune, Y.; Marui, N.; Matsuyama, T.; Meno, H.; Miyamoto, N.; Morikawa, S.; Myojin, K.; Nakamura, T.; Nishi, Y.; Ogawa, T.; Onaka, H.; Sakakibara, T.; Sakurai, S.; Sasaki, Y.; Sato, H.; Sugii, M.; Sumii, K.; Suzuki, S.; Takagi, M.; Takenaka, T.; Takeuchi, K.; Tanaka, S.; Tanouchi, J.; Ueda, K.; Ueyama, Y.; Ujihira, T.; Usui, M.; Yagi, M.; Yamada, T.; Yamamoto, H.; Yokochi, M.; Zen, E.; Abd Ghaphar, A. K.; Ang, C. K.; Chee, K. H.; Fong, A. F. Y.; Ismail, O.; Jeyaindran, S.; Kaur, S.; Lee, T. C.; Sandhu, R. S.; Shah, R. P.; Suganthi, S.; Zainal Abidin, S.; Alvarado-Ruiz, R.; Carrillo, J.; Delgado, E.; Fernandez Bonetti, P. A.; Leiva, J. L.; Meaney, A.; Olvera, R.; Peralta-Heredia, R.; Rodriguez, I.; Ruiz Rabasa, C. M.; Solache, G.; Villeda Espinosa, E.; Ahmed, S.; Badings, E.; Bartels, G. L.; Beganovic, M.; Bruning, T. A.; Ciampricotti, R.; Cozijnsen, L.; Crijns, H. J.; Daniels, M. C. G.; de Waard, D. E. P.; den Hartog, F. R.; Dirkali, A.; Groenemeijer, B. E.; Heesen, W. F.; Heijmeriks, J. A.; Hoogslag, P. A.; Huizenga, A.; Idzerda, H. H.; Kragten, J. A.; Krasznai, K.; Lenderink, T.; Liem, A. H.; Linssen, G. C.; Lok, D. J.; Meeder, J. G.; Michels, H. R.; Plomp, J.; Pos, L.; Posma, J. L.; Postema, P. G.; Salomonsz, R.; Stoel, I.; Tans, J. G.; Thijssen, H. J.; Timmermans, A. J. M.; Tteleman, R. G.; van Bergen, P. F. M. M.; van de Klippe, H. A.; van der Zwaan, C.; van Eck, J. W. M.; van Es, A. J. J.; van Gelder, I. C.; van Kempen, L. H.; van Kesteren, H. A.; van Rossum, P.; Veldmeyer, S.; Wilde, A. A. M.; Arnesen, H.; Atar, D.; Breder, O.; Istad, H.; Radunovic, Z.; Rykke, D. E.; Sirnes, P. A.; Tveit, A.; Ulimoen, S. R.; Cabrera, W.; Duenas, R.; Heredia, J. M.; Horna, M. E.; Hurtado, Y.; Salazar, P. M.; Abola, M. T. B.; Anonuevo, J. C.; Arellano, R. S.; Dioquino, C.; Morales, D. D.; Reyes, E. B.; Rogelio, G. G.; Roxas, A. A.; Sulit, D. J. V.; Bacior, B.; Dulak, E.; Gniot, J.; Goncikowski, J.; Grodecki, J.; Kalarus, Z. F.; Kawecka-Jaszcz, K.; Miekus, P.; Monies, F.; Piepiorka, M.; Pilichowska, E.; Plizio, E.; Rekosz, J.; Rybicka-Musialik, A.; Streb, W. A.; Styczkiewicz, M.; Szpajer, M.; Trusz-Gluza, M.; Wasilewska-Piepiorka, A.; Adragao, P.; Branco, V.; Canhão, P.; Cunha, L.; Falcão, F.; Lopes, G.; Machado, C.; Martinez-Marcos, J.; Monteiro, P. F.; Parreira, L.; Pinto, A. N.; Providencia, L. A.; Salgado, A. V.; Santos, J. F.; Timoteo, A. T.; Capalneanu, R.; Cinteza, M. A.; Margulesai, A. D.; Turdeanu, D. S.; Vintila, V. D.; Baranov, V. L.; Berngardt, E. R.; Dzhordzhikiya, T. R.; Gordeev, I. G.; Grigoryev, Y. V.; Isaeva, M. U.; Ivleva, A. Y.; Kokorin, V. A.; Komarov, A. L.; Maximenko, O. K.; Maykov, E. B.; Novikova, N.; Novikova, T. N.; Panchenko, E. P.; Poltavskaya, M. G.; Popova, Y. N.; Pronina, S. A.; Revishvili, A. Sh; Shlyakhto, E. V.; Shustov, S. B.; Sidorenko, B. A.; Sinopalnikov, A. I.; Sulimov, V.; Syrkin, A. L.; Titkov, A. Y.; Titkov, Y. S.; Zateyshchikov, D. A.; Zavaritskaya, O. P.; Chia, P. L.; Foo, D.; Sim, K. L.; Bugan, V.; Buganova, I.; Dúbrava, J.; Kaliska, G.; Masarovicova, M.; Mikes, P.; Mikes, Z.; Murin, J.; Pella, D.; Rybar, R.; Sedlák, J.; Skamla, M.; Spurný, P.; Strbova, J.; Uhliar, R.; Disler, L. J.; Engelbrecht, J. M.; Jankelow, D.; King, J.; Klug, E. Q.; Munnick, M.; Okreglicki, A. M.; Routier, R. J.; Snyders, F. A.; Theron, H. D.; Wittmer, H.; Cha, T. J.; Cho, J. G.; Choi, I. S.; Choi, J. I.; Choi, K. J.; Han, K. R.; Heo, J. H.; Jang, S. W.; Kang, T. S.; Kim, H. S.; Kim, K. S.; Kim, S. J.; Kim, S. S.; Kim, Y. H.; Kim, Y. N.; Lee, M. H.; Lee, M. Y.; Nam, G. B.; Oh, D. J.; Park, H. W.; Park, J. S.; Rho, T. H.; Shin, D. G.; Shin, E. K.; Alonso, J. J.; Cano, L.; Castellano, N. P.; Criado-Millan, A. J.; Curcio, A.; Egea, P.; Escudier, J. M.; Grande, A.; Grande, J. M.; Gusi-Tragant, G.; Lozano, I. F.; Martin, A. M.; Martinez-Rubio, A.; Mont, L.; Perez-Villacastin, J.; Sosa, L.; Ali, M.; Andersson, T.; Bandh, S.; Blomstrom Lundqvist, C. M.; Cherfan, P.; Fengsrud, E.; Fluur, C.; Herlitz, J.; Hijazi, Z.; Hoglund, N.; Hojeberg, B.; Jabro, J.; Juhlin, T.; Kjellman, B.; Lonnberg, I.; Maru, F.; Morlid, L.; Nilsson, O. R.; Ronn, F.; Rosenqvist, M.; Walfridsson, H.; Engelter, S. T.; Gallino, A.; Lyrer, P. A.; Moccetti, T.; Petrova, I.; Chang, Y. J.; Chen, C. H.; Chen, M. Y. C.; Cheng, J. J.; Chiang, T. R.; Chung, W. T.; Hsia, C. H.; Hsu, C. Y.; Hu, H. H.; Jeng, J. S.; Lai, W. T.; Lien, L. M.; Lin, K. H.; Liu, C. H.; Lo, H. S.; Peng, G. S.; Po, H. L.; Ryu, S. J.; Tsai, C. D.; Tsai, L. M.; Tseng, C. D.; Wang, J. H.; Wang, S. F.; Yang, S. P.; Kiatchoosakun, S.; Krittayaphong, R.; Kuanprasert, S.; Ngarmukos, T.; Simtharakaew, T.; Sukanandachai, B.; Sukonthasam, A.; Suwanagool, A.; Tatsanavivat, P.; Atmaca, Y.; Baris, N.; Boyaci, B.; Demir, M.; Guneri, S.; Usal, A.; Yalcin, R.; Amosova, K. M.; Beregova, O. P.; Besaga, Y. E. M.; Ikorkin, M. R.; Karapetyan, K.; Karpenko, O. I.; Kononenko, L.; Kuryata, O.; Martynova, L.; Motylevska, T.; Okhryamkina, O.; Pavlyk, S. S.; Perepelytsya, M. V.; Rudenko, L. V.; Skarzhevsky, O. A.; Tkachenko, L. A.; Tseluyko, V.; Usan, N.; Voronkov, L. G.; Yshchenko, K. V.; Zharinov, O. J.; Bryson, V. G.; Butler, R.; Cargill, R. I.; Chahal, N. S.; Cleland, J. G.; Cohen, A. T.; Cruddas, E. M.; Davey, P.; Davies, J.; Ford, S. L.; Griffith, K.; Haynes, R.; Hill, S.; Javed, M.; Kadr, H. H.; Lip, G. H.; Machin, J.; McEneaney, D. J.; McInnes, G. T.; McNeill, A. J.; Moriarty, A. J.; Muir, S.; O'Callaghan, J.; Purvis, J. A.; Pye, M.; Senior, R.; Sutton, D. A.; Thomas, S. H. L.; Wilkinson, P. R.; Wilmott, R.; Wrigley, M. J.; Abadier, R.; Abbud, Z. A.; Adams, K. V.; Adler, S. W.; Agarwal, S.; Ahmed, A. M.; Ahmed, I. S.; Aiuto, M. A.; Albrittun, T. D.; Aliyar, P.; Allan, J. J.; Allen, D. P.; Allen, S. L.; Altschuller, A.; Amin, M.; Anand, I. S.; Antolick, A. B.; Arora, R.; Arouni, A. J.; Arslanian, C. L.; Asinger, R. W.; Aycock, G. R.; Bariciano, R. J.; Baron, S. B.; Barr, M. A.; Bartkowiak, A. J.; Baruch, L.; Basignani, C.; Bass, M. L.; Bean, B.; Bedwell, N. W.; Belber, A. D.; Belew, K.; Bell, Y. C.; Bellinger, R. L.; Bennett, W. T.; Bensimhon, D. R.; Benton, R.; Benton, R. E.; Ben-Yehuda, O.; Bertolet, B. D.; Betkowski, A. S.; Bilazarian, S. D.; Bissette, J. K.; Bobade, M. B.; Bolster, D. E.; Bomba, J.; Book, D. M.; Boscia, J. A.; Bouchard, A.; Bowman, L. M.; Bradley, A. J.; Brandt, H. D.; Bricker, C. R.; Brobyn, T. L.; Brock, R. I.; Broderick, T. M.; Broedlin, K.; Brown, A. M.; Browne, K. F.; Burke, S. W.; Burton, M. E.; Buser, G. A.; Capasso, M. K.; Caplan, W. E.; Cappelli, J.; Cardona, C.; Cardona, F.; Carlson, T.; Carr, K. W.; Casey, T.; Cashion, W. R.; Cass, D. T.; Chandrashekar, Y. S.; Changlani, M.; Chapla, P. G.; Chappell, J. H.; Chen, C.; Chen, Y.; Cho, N. R.; Cieszkowski, J. H.; Clark, D. M.; Clayton, R.; Clogston, C. W.; Cockrell, D. J.; Cohen, A. I.; Cohen, T. J.; Cole, J. F.; Conway, G.; Cook, V. R.; Cornish, A. L.; Cossu, S. F.; Costello, D. L.; Courtade, D. J.; Covelli, H. C.; Crenshaw, B. S.; Crews, L. A.; Crossley, G. H.; Culp, S. C.; Curtis, B. M.; Darrow, K.; de Raad, R. E.; DeGregorio, M.; DelNegro, A. A.; Denny, D. M.; Desai, V. S.; Deumite, N. J.; Dewey, L.; Dharawat, R. N.; Dobbs, B.; Donahue, S. M.; Downey, B.; Downing, J.; Drehobl, M. A.; Drewes, W. A.; Drucker, M. N.; Duff, R.; Duggal, M.; Dunlap, S. H.; Dunning, D. W.; DuThinh, V.; Dykstra, G. T.; East, C.; Eblaghie, M. C.; Edelstein, J.; Edmiston, W. A.; Eisen, H. J.; Eisenberg, S. J.; Ellis, J. R.; Ellison, H. S.; Ellsworth, S.; Elshahawy, M.; Emlein, G.; Entcheva, M.; Essandoh, L. K.; Estrada, A. Q.; Ewing, B.; Faillace, R. T.; Fanelli, A.; Farrell, P. W.; Farris, S. W.; Fattal, P. G.; Feigenblum, D. Y.; Feldman, G. J.; Fialkow, J. A.; Fiddler, K. M.; Fields, R. H.; Finkel, M. S.; Finn, C.; Fischell, T. A.; Fishbach, M.; Fishbein, G. J.; Fisher, M. M.; Fleischhauer, F. J.; Folk, T. G.; Folkerth, S. D.; Fortman, R. R.; Frais, M. A.; Friedman, D. C.; Fuchs, G.; Fuller, F.; Garibian, G.; Gee, F. H.; Gelernt, M. D.; Genovely, H. C.; Gerber, J. R.; Germano, J. J.; Giardina, J. J.; Gilbert, J. M.; Gillespie, E. L.; Gilman, E. M.; Gitler, B.; Givens, D. H.; Glover, R.; Gogia, H. S.; Gohn, D. C.; Goldberg, R. K.; Goldberger, J. J.; Goldscher, D. A.; Goldstein, M.; Goraya, T.; Gordon, D. F.; Gottlieb, D.; Grafner, H. L.; Graham, M.; Graves, M. W.; Graziano, M.; Greco, S. N.; Greenberg, M. L.; Greenspon, A. J.; Greer, G. S.; Griffin, D. D.; Grogan, E. W.; Groo, V. L.; Guarnieri, T.; Gupta, A.; Gupta, J.; Hack, T. C.; Hall, B.; Hallak, O.; Halpern, S. W.; Hamburg, C.; Hamroff, G. S.; Han, J.; Handel, F.; Hankins, S. R.; Hanovich, G. D.; Hanrahan, J. A.; Haque, I. U.; Hargrove, J. L.; Harnick, P. E.; Harris, J. L.; Hartley, P. A.; Haskel, E. J.; Hatch, D.; Haught, W. H.; Hearne, S.; Hearne, S. E.; Hemphill, J. A.; Henderson, D. A.; Henes, C. H.; Hengerer-Yates, T.; Hermany, P. R.; Herzog, W. R.; Hickey, K.; Hilton, T. C.; Hockstad, E. S.; Hodnett, P.; Hoffmeister, R.; Holland, J.; Hollenweger, L.; Honan, M. B.; Hoopes, D. A.; Hordes, A. R.; Hotchkiss, D. A.; Howard, M. A.; Howard, V. N.; Hulyalkar, A. R.; Hurst, P.; Hutchison, L. C.; Ingram, J.; Isakov, T.; Ison, R. K.; Israel, C. N.; Jackson, B. K.; Jackson, K. N.; Jacobson, A. K.; Jain, S.; Jarmukli, N. F.; Joffe, I.; Johnson, L. E.; Johnson, S. A.; Johnson, S. L.; Jones, A. A.; Joyce, D. B.; Judson, P. L.; Juk, S. S.; Kaatz, S.; Kaddaha, R. M.; Kaplan, K. J.; Karunaratne, H. B.; Kennett, J. D.; Kenton, D. M.; Kettunen, J. A.; Khan, M. A.; Khant, R. N.; Kirkwood, M. D.; Knight, B. P.; Knight, P. O.; Knutson, T. J.; Kobayashi, J. F.; Kogan, A.; Kogan, A. D.; Koren, M. J.; Kosinski, E. J.; Kosolcharoen, P.; Kostis, J. B.; Kramer, J. H.; Kramer, S. D.; Kron, J.; Kuchenrither, C. R.; Kulback, S. J.; Kumar, A.; Kushner, D.; Kutscher, A.; Lai, C. K.; Lam, J. B.; Landau, C.; Landzberg, J. S.; Lang, D. T.; Lang, J. M.; Lanzarotti, C. J.; Lascewski, D. L.; Lau, T. K.; Lee, J. K.; Lee, S.; Leimbach, W. N.; LePine, A. M.; Lesser, M. F.; Leuchak, S. H.; Levy, R. M.; Lewis, W. R.; Lincoln, T. L.; Lingerfelt, W. M.; Liston, M.; Liu, Z. G.; Lloret, R. L.; Lohrbauer, L.; Longoria, D. C.; Lott, B. M.; Louder, D. R.; Loukinen, K. L.; Lovell, J.; Lue, S.; Mackall, J. A.; Maletz, L.; Marlow, L.; Martin, R. C.; Matsumura, M.; McCartney, M. J.; McDuffie, D.; McGough, M. F.; McGrew, F. A.; McGuinn, Wm P.; McMillen, M. D.; McNeff, J.; McPherson, C. A.; Meengs, M. E.; Meengs, W. L.; Meholick, A. W.; Meisner, J. S.; Melucci, M. B.; Mercando, A.; Merlino, J. D.; Meymandi, S. K.; Miele, M. B.; Miller, R. H.; Miller, S. H.; Minor, S. T.; Mitchell, M. R.; Modi, M.; Mody, F. V.; Moeller, C. L.; Moloney, J. F.; Moran, J. E.; Morcos, N. C.; Morgan, A.; Mukherjee, S. K.; Mullinax, K.; Murphy, A. L.; Mustin, A. J.; Myers, G. I.; Naccarelli, G. V.; Nadar, V. K.; Nallasivan, M.; Navas, J. P.; Niazi, I. K.; Nsah, E. N.; Nunamaker, J. L.; Ochalek, T. B.; O'dea, D. J.; Ogilvie, P. D.; Olliff, B.; Omalley, A. K.; O'Neill, P. G.; Onufer, J. R.; Orchard, R. C.; Orihuela, L. A.; Ortiz, E. C.; O'Sullivan, M. T.; Padanilam, B. J.; Pandey, P.; Patel, D. V.; Patel, R. J.; Patel, V. B.; Patlola, R. R.; Pennock, G. D.; Perlman, R.; Peters, P. H.; Petrillo, A. V.; Pezzella, S.; Phillips, D.; Pierre-Louis, J. R.; Pilcher, G.; Pillai, C.; Pollock, S. G.; Pond, M. S.; Porterfield, J. K.; Presant, L.; Pressler, J.; Pribble, A. H.; Promisloff, S. D.; Pudi, K. K.; Putnam, D. L.; Quartner, J.; Quinn, J. C.; Quinnell, C. M.; Raad, G. L.; Rasmussen, L. A.; Ray, C.; Reiffel, J. A.; Reynertson, S.; Richardson, J. W.; Riley, C. P.; Rippy, J. S.; Rittelmeyer, J. T.; Roberts, D. M.; Robertson, R.; Robinson, V. J. B.; Rocco, T. A.; Rosenbaum, D.; Roth, E. M.; Rottman, J. N.; Rough, R. R.; Rubenstein, J. J.; Sakkal, A. M.; Saleem, T.; Salerno, D. M.; Samendinger, M. L.; Sandeno, S.; Santilli, T. M.; Santucci, P.; Sattar, P.; Saxman, K. A.; Schaefer, S.; Schmidt, J.; Schneider, R. M.; Schocken, D. D.; Schrader, M. K.; Schramm, B. A.; Schultz, R. W.; Schussheim, A. E.; Schwarz, E. F.; Seamon, M. C.; Sestero, J. D.; Shah, M. P.; Shah, R.; Shalaby, A.; Shanes, J. G.; Sheftel, G. L.; Sheikh, K. H.; Shein, A. B.; Shemonsky, N. K.; Shepler, A.; Sheridan, E.; Shipwash, T. M.; Shopnick, R. I.; Short, W. G.; Shoukfeh, M. F.; Sibia, R. S.; Siler, T. M.; Silva, J. A.; Simons, G. R.; Simpson, A. G.; Simpson, H. R.; Simpson, V. J.; Singh, B. N.; Singh, N.; Singh, V. N.; Sitz, C. J.; Skatrud, L.; Sklar, J.; Slotwiner, D. J.; Smith, P. F.; Smith, P. N.; Smith, R. H.; Smith, J. E.; Sodowick, B. C.; Solomon, A. J.; Soltero, E. A.; Sonel, A. F.; Sperling, R.; Spiller, C.; Spink, B. Z.; Sprinkle, L. W.; Spyropoulos, A. C.; Stamos, T. D.; Steljes, A. D.; Stillabower, M. E.; Stover, T.; Strain, J. E.; Strickland, T. L.; Suresh, D. P.; Takata, T. S.; Taylor, J. S.; Taylor, M.; Teague, S. M.; Teixeia, J. M.; Telfer, E. A.; Terry, P. S.; Terry, R. W.; Thai, H. M.; Thalin, M.; Thomas, V. N.; Thompson, C. A.; Thompson, M. A.; Thornton, J. W.; Tidman, R. E.; Toler, B. S.; Traina, M. I.; Trippi, J. A.; Ujiiye, D. L.; Usedom, J. E.; van de Graaff, E.; van de Wall, L. R.; Vaughn, J. W.; Ver Steeg, D.; Vicari, R. M.; Vijay, N.; Vitale, C. B.; Vlastaris, A. G.; Voda, J.; Vora, K. N.; Voyles, W. F.; Vranian, R. B.; Vrooman, P. S.; Waack, P.; Waldo, A. L.; Walker, J. L.; Wallace, M. A.; Walsh, E. A.; Walsh, R. L.; Walton, A.; Washam, M.; Wehner, P. S.; Wei, J. Y.; Weiner, S.; Weiss, R. J.; Wells, D. M.; Wera-Archakul, W.; Wertheimer, J. H.; West, S. A.; Whitaker, J. H.; White, M. L.; White, R. H.; Whitehill, J. N.; Wiegman, P. J.; Wiesel, J.; Williams, J.; Williams, L. E.; Williams, M. L.; Williamson, V. K.; Wilson, V. E.; Wilson, W. W.; Woodfield, S. L.; Wulff, C. W.; Yates, S. W.; Yousuf, K. A.; Zakhary, B. G.; Zambrano, R.; Zimetbaum, P.; Zoble, R.; Zopo, A. R.; Zwerner, P. L.

    2009-01-01

    BACKGROUND: Warfarin reduces the risk of stroke in patients with atrial fibrillation but increases the risk of hemorrhage and is difficult to use. Dabigatran is a new oral direct thrombin inhibitor. METHODS: In this noninferiority trial, we randomly assigned 18,113 patients who had atrial

  20. EFFECT OF EXERCISE ON CYCLE LENGTH IN ATRIAL-FLUTTER

    NARCIS (Netherlands)

    VANDENBERG, MP; CRIJNS, HJGM; SZABO, BM; BROUWER, J; LIE, KI

    Objective-To examine the effect of exercise on cycle length in atrial flutter. Patients-15 patients with chronic atrial flutter. Seven patients were taking digoxin and six verapamil; two were not taking medication. Methods-All patients underwent bicycle ergometry. Flutter cycle length was measured

  1. Atrial fibrillation and bleeding complication - risk factors and risk marker

    NARCIS (Netherlands)

    Breithardt, G.; Ravens, U.; Kirchhof, P.; van Gelder, I. C.

    2012-01-01

    The development of atrial fibrillation (AF) is closely linked to risk factors like hypertension and heart failure, diabetes mellitus, myocardial infarction and valvular heart disease. These factors partly overlap with those which determine the progression of atrial fibrillation and the incidence of

  2. 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...

  3. Right atrial myxoma at Muhimbili National Hospital: a case report ...

    African Journals Online (AJOL)

    lower cava hypertension and was in NYHA class IV. The 2-D echocardiography revealed a right atrial tumor encroaching the tricuspid valve, chest radiography showed gross cardiomegally and right lower lung collapse. A clinical diagnosis of right atrial tumour was reached. The patient was scheduled to undergo open heart ...

  4. Fractional quantum mechanics

    CERN Document Server

    Laskin, Nick

    2018-01-01

    Fractional quantum mechanics is a recently emerged and rapidly developing field of quantum physics. This is the first monograph on fundamentals and physical applications of fractional quantum mechanics, written by its founder. The fractional Schrödinger equation and the fractional path integral are new fundamental physical concepts introduced and elaborated in the book. The fractional Schrödinger equation is a manifestation of fractional quantum mechanics. The fractional path integral is a new mathematical tool based on integration over Lévy flights. The fractional path integral method enhances the well-known Feynman path integral framework. Related topics covered in the text include time fractional quantum mechanics, fractional statistical mechanics, fractional classical mechanics and the α-stable Lévy random process. The book is well-suited for theorists, pure and applied mathematicians, solid-state physicists, chemists, and others working with the Schrödinger equation, the path integral technique...

  5. Left Atrial Sphericity Index Predicts Early Recurrence of Atrial Fibrillation After Direct-Current Cardioversion

    DEFF Research Database (Denmark)

    Osmanagic, Armin; Möller, Sören; Osmanagic, Azra

    2016-01-01

    BACKGROUND: Attempts to achieve rhythm control using direct-current cardioversion (DCC) are common in those with persistent atrial fibrillation (AF). Although often successful, AF recurs within 1 month in as many as 57% of patients. The aim of this study was to assess whether a baseline left atri...

  6. Does Myocardial Infarction Beget Atrial Fibrillation and Atrial Fibrillation Beget Myocardial Infarction?

    NARCIS (Netherlands)

    Vermond, Rob A.; Van Gelder, Isabelle C.; Crijns, Harry J.; Rienstra, Michiel

    2015-01-01

    Atrial fibrillation (AF) affects millions of people worldwide.(1) It is already known several decades that AF is not a benign condition, and it's associated with a 5-fold increased risk of stroke, 3-fold increased risk of heart failure, and doubling of risk of dementia and death.(2-4) Myocardial

  7. Family history of atrial fibrillation is associated with earlier-onset and more symptomatic atrial fibrillation

    DEFF Research Database (Denmark)

    Gundlund, Anna; Fosbøl, Emil Loldrup; Kim, Sunghee

    2016-01-01

    BACKGROUND: We addressed whether patients with a family history of atrial fibrillation (AF) were diagnosed as having AF earlier in life, were more symptomatic, and had worse outcomes compared with those without a family history of AF. METHODS: Using the ORBIT-AF, we compared symptoms and disease...

  8. [Recurrent right atrial thrombus in a patient with atrial fibrillation and heart failure].

    Science.gov (United States)

    Elikowski, Waldemar; Wróblewski, Dariusz; Małek-Elikowska, Małgorzata; Mazurek, Andrzej; Foremska-Iciek, Joanna; Łazowski, Stanisław

    2015-11-01

    Atrial fibrillation and heart failure are factors predisposing to locally formed intracardiac thrombosis, which is usually localized in left-sided chambers. A case report. The authors present a case of a 50-year-old male with permanent atrial fibrillation and dilated cardiomyopathy in whom recurrent right atrial thrombus was observed. Initially, the lesion was detected in echocardiography while he was hospitalized due to extensive right-sided pneumonia. The thrombus was successfully treated with heparin, followed by warfarin. Even though the patient continued warfarin use properly, there was recurrence of the thrombus two years later during a new episode of heart failure exacerbation. Because the thrombus was resistant to intensified anticoagulation, cardiac surgery was needed. A large (30 x 25 mm) pedunculated thrombus, as well as two smaller ones (each of 10 x 10 mm) attached closely to the atrial wall and previously not detected either by echocardiography or by magnetic resonance imaging, were excited. A partially organized pattern of the thrombi in histological examination can explain lack of anticoagulation effectiveness. © 2015 MEDPRESS.

  9. 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

    Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia encountered in clinical practice. One of its most devastating complications is the development of thromboembolism leading to fatal or disabling stroke. Oral anticoagulation (OAC, warfarin) is the standard treatment for strok...

  10. Fractional vector calculus and fractional Maxwell's equations

    International Nuclear Information System (INIS)

    Tarasov, Vasily E.

    2008-01-01

    The theory of derivatives and integrals of non-integer order goes back to Leibniz, Liouville, Grunwald, Letnikov and Riemann. The history of fractional vector calculus (FVC) has only 10 years. The main approaches to formulate a FVC, which are used in the physics during the past few years, will be briefly described in this paper. We solve some problems of consistent formulations of FVC by using a fractional generalization of the Fundamental Theorem of Calculus. We define the differential and integral vector operations. The fractional Green's, Stokes' and Gauss's theorems are formulated. The proofs of these theorems are realized for simplest regions. A fractional generalization of exterior differential calculus of differential forms is discussed. Fractional nonlocal Maxwell's equations and the corresponding fractional wave equations are considered

  11. Atrial fibrillation and vascular disease-a bad combination

    DEFF Research Database (Denmark)

    Bjerring Olesen, Jonas; Gislason, Gunnar Hilmar; Torp-Pedersen, Christian

    2012-01-01

    This article provides an overview of (i) the risk of stroke associated with vascular disease (acute coronary syndromes and peripheral artery disease) in patients with atrial fibrillation, (ii) the frequent coexistence of vascular disease in patients with atrial fibrillation and, (iii...... fibrillation. Indeed, patients with atrial fibrillation often had coexisting vascular disease (around 18%), and the combination of the two diseases substantially increases the risk of future cardiovascular events. The increased risk associated with peripheral artery disease in atrial fibrillation is even more...... pronounced. Patients with atrial fibrillation and stable vascular disease should be treated with oral anticoagulation only, although when these patients present with acute coronary syndrome and/or undergo coronary stenting, concomitant treatment with antiplatelet drugs is indicated. To guide antithrombotic...

  12. Atrial Arrhythmias in Astronauts. Summary of a NASA Summit

    Science.gov (United States)

    Barr, Yael; Watkins, Sharmila; Polk, J. D.

    2011-01-01

    This slide presentation reviews the findings of a panel of heart experts brought together to study if atrial arrhythmias more prevalent in astronauts, and potential risk factors that may predispose astronauts to atrial arrhythmias. The objective of the panel was to solicit expert opinion on screening, diagnosis, and treatment options, identify gaps in knowledge, and propose relevant research initiatives. While Atrial Arrhythmias occur in approximately the same percents in astronauts as in the general population, they seem to occur at younger ages in astronauts. Several reasons for this predisposition were given: gender, hypertension, endurance training, and triggering events. Potential Space Flight-Related Risk factors that may play a role in precipitating lone atrial fibrillation were reviewed. There appears to be no evidence that any variable of the space flight environment increases the likelihood of developing atrial arrhythmias during space flight.

  13. Genetics of Atrial Fibrillation and Possible Implications for Ischemic Stroke

    Directory of Open Access Journals (Sweden)

    Robin Lemmens

    2011-01-01

    Full Text Available Atrial fibrillation is the most common cardiac arrhythmia mainly caused by valvular, ischemic, hypertensive, and myopathic heart disease. Atrial fibrillation can occur in families suggesting a genetic background especially in younger subjects. Additionally recent studies have identified common genetic variants to be associated with atrial fibrillation in the general population. This cardiac arrhythmia has important public health implications because of its main complications: congestive heart failure and ischemic stroke. Since atrial fibrillation can result in ischemic stroke, one might assume that genetic determinants of this cardiac arrhythmia are also implicated in cerebrovascular disease. Ischemic stroke is a multifactorial, complex disease where multiple environmental and genetic factors interact. Whether genetic variants associated with a risk factor for ischemic stroke also increase the risk of a particular vascular endpoint still needs to be confirmed in many cases. Here we review the current knowledge on the genetic background of atrial fibrillation and the consequences for cerebrovascular disease.

  14. 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

  15. Fractional statistics and fractional quantized Hall effect

    International Nuclear Information System (INIS)

    Tao, R.; Wu, Y.S.

    1985-01-01

    The authors suggest that the origin of the odd-denominator rule observed in the fractional quantized Hall effect (FQHE) may lie in fractional statistics which govern quasiparticles in FQHE. A theorem concerning statistics of clusters of quasiparticles implies that fractional statistics do not allow coexistence of a large number of quasiparticles at fillings with an even denominator. Thus, no Hall plateau can be formed at these fillings, regardless of the presence of an energy gap. 15 references

  16. Atrial Fibrillation: When the heart is not in rhythm | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... of this page please turn JavaScript on. Feature: Atrial Fibrillation Atrial Fibrillation: When the heart is not in rhythm Past ... show, Deal With It . Photo: TBS/Deal Understanding Atrial Fibrillation Atrial fibrillation (AFib) is the most common type ...

  17. Anomalous muscle bundle in the right atrium; Implication to trans atrial device closure

    Directory of Open Access Journals (Sweden)

    Saji Philip

    2017-09-01

    Full Text Available Intracavitary muscle bands or aberrant bands have been well described in all four chambers of the heart but rarely seen thick muscular band crossing right atrium. We report a case of devisable secundum atrial septal defect with an intra-atrial anomalous muscular band, crossing right atrial wall to the rim of the secundum atrial septal defect warranting surgical closure.

  18. Pulmonary artery-to-left atrial fistula discovered after the closure of atrial septal defect: A rare clinical scenario

    Directory of Open Access Journals (Sweden)

    Akshay Chauhan

    2018-01-01

    Full Text Available A case of the right pulmonary artery-to- left atrial fistula with atrial septal defect (ASD is presented. The fistula was detected after the patient developed desaturation following surgical closure of the ASD. It was managed with a transcatheter (trans-RPA route closure of the fistula using a 12-mm Amplatzer ventricular septal defect closure device.

  19. Does Left Atrial Volume and Pulmonary Venous Anatomy Predict the Outcome of Catheter Ablation of Atrial Fibrillation ?

    NARCIS (Netherlands)

    Hof, Irene; Chilukuri, Karuna; Arbab-Zadeh, Armin; Scherr, Daniel; Dalal, Darshan; Nazarian, Saman; Henrikson, Charles; Spragg, David; Berger, Ronald; Marine, Joseph; Calkins, Hugh

    Introduction: Preprocedural factors may be helpful in selecting patients with atrial fibrillation (AF) for treatment with catheter ablation and in making an assumption regarding their prognosis. The aims of this study were to investigate whether left atrial (LA) volume and pulmonary venous (PV)

  20. Initialized Fractional Calculus

    Science.gov (United States)

    Lorenzo, Carl F.; Hartley, Tom T.

    2000-01-01

    This paper demonstrates the need for a nonconstant initialization for the fractional calculus and establishes a basic definition set for the initialized fractional differintegral. This definition set allows the formalization of an initialized fractional calculus. Two basis calculi are considered; the Riemann-Liouville and the Grunwald fractional calculi. Two forms of initialization, terminal and side are developed.

  1. Direct Proof of Endo-Epicardial Asynchrony of the Atrial Wall During Atrial Fibrillation in Humans.

    Science.gov (United States)

    de Groot, Natasja; van der Does, Lisette; Yaksh, Ameeta; Lanters, Eva; Teuwen, Christophe; Knops, Paul; van de Woestijne, Pieter; Bekkers, Jos; Kik, Charles; Bogers, Ad; Allessie, Maurits

    2016-05-01

    The presence of focal fibrillation waves during atrial fibrillation (AF) can, besides ectopic activity, also be explained by asynchronous activation of the atrial endo- and epicardial layer and transmurally propagating fibrillation waves. To provide direct proof of endo-epicardial asynchrony, we performed simultaneous high-resolution mapping of the right atrial endo- and epicardial wall during AF in humans. Intraoperative mapping of the endo- and epicardial right atrial wall was performed during (induced) AF in 10 patients with AF (paroxysmal: n=3; persistent: n=4; and longstanding persistent: n=3) and 4 patients without a history of AF. A clamp made of 2 rectangular 8×16 electrode arrays (interelectrode distance 2 mm) was inserted into the incision in the right atrial appendage. Recordings of 10 seconds of AF were analyzed to determine the incidence of asynchronous endo-epicardial activation times (≥15 ms) of opposite electrodes. Asynchronous endo-epicardial activation ranged between 0.9 and 55.9% without preference for either side. Focal waves appeared equally frequent at endocardium and epicardium (11% versus 13%; ITALIC! P=0.18). Using strict criteria for breakthrough (presence of an opposite wave within 4 mm and ≤14 ms before the origin of the focal wave), the majority (65%) of all focal fibrillation waves could be attributed to endo-epicardial excitation. We provided the first evidence for asynchronous activation of the endo-epicardial wall during AF in humans. Endo-epicardial asynchrony may play a major role in the pathophysiology of AF and may offer an explanation why in some patients therapy fails. © 2016 American Heart Association, Inc.

  2. Interatrial septum pacing decreases atrial dyssynchrony on strain rate imaging compared with right atrial appendage pacing.

    Science.gov (United States)

    Yasuoka, Yoshinori; Abe, Haruhiko; Umekawa, Seiko; Katsuki, Keiko; Tanaka, Norio; Araki, Ryo; Imanaka, Takahiro; Matsutera, Ryo; Morisawa, Daisuke; Kitada, Hirokazu; Hattori, Susumu; Noda, Yoshiki; Adachi, Hidenori; Sasaki, Tatsuya; Miyatake, Kunio

    2011-03-01

    Interatrial septum pacing (IAS-P) decreases atrial conduction delay compared with right atrial appendage pacing (RAA-P). We evaluate the atrial contraction with strain rate of tissue Doppler imaging (TDI) during sinus activation or with IAS-P or RAA-P. Fifty-two patients with permanent pacemaker for sinus node disease were enrolled in the study. Twenty-three subjects were with IAS-P and 29 with RAA-P. The time from end-diastole to peak end-diastolic strain rate was measured and corrected with RR interval on electrocardiogram. It was defined as the time from end-diastole to peak end-diastolic strain rate (TSRc), and the balance between maximum and minimum TSRc at three sites (ΔTSRc) was compared during sinus activation and with pacing rhythm in each group. There were no significant differences observed in general characteristics and standard echocardiographic parameters except the duration of pacing P wave between the two groups. The duration was significantly shorter in the IAS-P group compared with the RAA-P group (95 ± 34 vs 138 ± 41; P = 0.001). TSRc was significantly different between sinus activation and pacing rhythm (36.3 ± 35.7 vs 61.6 ± 36.3; P = 0.003) in the RAA-P group, whereas no significant differences were observed in the IAS-P group (25.4 ± 12.1 vs 27.7 ± 14.7; NS). During the follow-up (mean 2.4 ± 0.7 years), the incidence of paroxysmal atrial fibrillation (AF) conversion to permanent AF was not significantly different between the two groups. IAS-P decreased the contraction delay on atrial TDI compared to RAA-P; however, it did not contribute to the reduction of AF incidence in the present study. ©2010, The Authors. Journal compilation ©2010 Wiley Periodicals, Inc.

  3. Atrial-selective K+ channel blockers: potential antiarrhythmic drugs in atrial fibrillation?

    Science.gov (United States)

    Ravens, Ursula

    2017-11-01

    In the wake of demographic change in Western countries, atrial fibrillation has reached an epidemiological scale, yet current strategies for drug treatment of the arrhythmia lack sufficient efficacy and safety. In search of novel medications, atrial-selective drugs that specifically target atrial over other cardiac functions have been developed. Here, I will address drugs acting on potassium (K + ) channels that are either predominantly expressed in atria or possess electrophysiological properties distinct in atria from ventricles. These channels include the ultra-rapidly activating, delayed outward-rectifying Kv1.5 channel conducting I Kur , the acetylcholine-activated inward-rectifying Kir3.1/Kir3.4 channel conducting I K,ACh , the Ca 2+ -activated K + channels of small conductance (SK) conducting I SK , and the two-pore domain K + (K2P) channels (tandem of P domains, weak inward-rectifying K + channels (TWIK-1), TWIK-related acid-sensitive K + channels (TASK-1 and TASK-3)) that are responsible for voltage-independent background currents I TWIK-1 , I TASK-1 , and I TASK-3 . Direct drug effects on these channels are described and their putative value in treatment of atrial fibrillation is discussed. Although many potential drug targets have emerged in the process of unravelling details of the pathophysiological mechanisms responsible for atrial fibrillation, we do not know whether novel antiarrhythmic drugs will be more successful when modulating many targets or a single specific one. The answer to this riddle can only be solved in a clinical context.

  4. [Left atrial electric isolation in the treatment of atrial fibrillation secondary to rheumatic valvular disease].

    Science.gov (United States)

    Graffigna, A; Pagani, F; Minzioni, G; Salerno, J; Viganò, M

    1992-08-01

    Surgical isolation of the left atrium was performed for the treatment of chronic atrial fibrillation secondary to valvular disease in 100 patients who underwent valve surgery. From May 1989 to September 1991, 62 patients underwent mitral valve surgery (Group I), 19 underwent mitral valve surgery and DeVega tricuspid annuloplasty (Group II), 15 underwent mitral and aortic surgery (Group III), and 4 patients underwent mitral and aortic surgery and DeVega tricuspid annuloplasty (Group IV). Left atrial isolation was performed prolonging the usual left paraseptal atriotomy towards the left fibrous trigone anteriorly, and the postero-medial commissure posteriorly. The incision was conducted a few millimeters apart from the mitral valve annulus, and cryolesion were placed at the edges to ensure complete electrophysiological isolation of the left atrium. Operative mortality accounted for 3 cases (3%). In 79 patients (81.4%) sinus rhythm recovered and persisted until discharge from the hospital. No differences were found between the groups (Group I: 80.7%; Group II: 68.5%; Group III 86.7%, Group IV 75% - p = N.S.). Three cases of late mortality (3.1%) were registered. long-term results showed persistence of SR in 71% of Group I, 61.2% of Group II, 85.8% of Group III, and 100% of Group IV. The unique risk factor for late recurrency of atrial fibrillation was found to be a duration of preoperative AF longer than 6 months. Due to the high success rate in recovering the sinus rhythm, we suggest left atrial isolation in patients with chronic atrial fibrillation undergoing valvular surgery.

  5. Tempered fractional calculus

    Energy Technology Data Exchange (ETDEWEB)

    Sabzikar, Farzad, E-mail: sabzika2@stt.msu.edu [Department of Statistics and Probability, Michigan State University, East Lansing, MI 48823 (United States); Meerschaert, Mark M., E-mail: mcubed@stt.msu.edu [Department of Statistics and Probability, Michigan State University, East Lansing, MI 48823 (United States); Chen, Jinghua, E-mail: cjhdzdz@163.com [School of Sciences, Jimei University, Xiamen, Fujian, 361021 (China)

    2015-07-15

    Fractional derivatives and integrals are convolutions with a power law. Multiplying by an exponential factor leads to tempered fractional derivatives and integrals. Tempered fractional diffusion equations, where the usual second derivative in space is replaced by a tempered fractional derivative, govern the limits of random walk models with an exponentially tempered power law jump distribution. The limiting tempered stable probability densities exhibit semi-heavy tails, which are commonly observed in finance. Tempered power law waiting times lead to tempered fractional time derivatives, which have proven useful in geophysics. The tempered fractional derivative or integral of a Brownian motion, called a tempered fractional Brownian motion, can exhibit semi-long range dependence. The increments of this process, called tempered fractional Gaussian noise, provide a useful new stochastic model for wind speed data. A tempered fractional difference forms the basis for numerical methods to solve tempered fractional diffusion equations, and it also provides a useful new correlation model in time series.

  6. Tempered fractional calculus

    Science.gov (United States)

    Sabzikar, Farzad; Meerschaert, Mark M.; Chen, Jinghua

    2015-07-01

    Fractional derivatives and integrals are convolutions with a power law. Multiplying by an exponential factor leads to tempered fractional derivatives and integrals. Tempered fractional diffusion equations, where the usual second derivative in space is replaced by a tempered fractional derivative, govern the limits of random walk models with an exponentially tempered power law jump distribution. The limiting tempered stable probability densities exhibit semi-heavy tails, which are commonly observed in finance. Tempered power law waiting times lead to tempered fractional time derivatives, which have proven useful in geophysics. The tempered fractional derivative or integral of a Brownian motion, called a tempered fractional Brownian motion, can exhibit semi-long range dependence. The increments of this process, called tempered fractional Gaussian noise, provide a useful new stochastic model for wind speed data. A tempered fractional difference forms the basis for numerical methods to solve tempered fractional diffusion equations, and it also provides a useful new correlation model in time series.

  7. Tempered fractional calculus

    International Nuclear Information System (INIS)

    Sabzikar, Farzad; Meerschaert, Mark M.; Chen, Jinghua

    2015-01-01

    Fractional derivatives and integrals are convolutions with a power law. Multiplying by an exponential factor leads to tempered fractional derivatives and integrals. Tempered fractional diffusion equations, where the usual second derivative in space is replaced by a tempered fractional derivative, govern the limits of random walk models with an exponentially tempered power law jump distribution. The limiting tempered stable probability densities exhibit semi-heavy tails, which are commonly observed in finance. Tempered power law waiting times lead to tempered fractional time derivatives, which have proven useful in geophysics. The tempered fractional derivative or integral of a Brownian motion, called a tempered fractional Brownian motion, can exhibit semi-long range dependence. The increments of this process, called tempered fractional Gaussian noise, provide a useful new stochastic model for wind speed data. A tempered fractional difference forms the basis for numerical methods to solve tempered fractional diffusion equations, and it also provides a useful new correlation model in time series

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

    International Nuclear Information System (INIS)

    Murdoch, Dale; McAulay, Laura; Walters, Darren L.

    2014-01-01

    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

  9. 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.

  10. NASA's First Atrial Fibrillation Case - Deke Slayton

    Science.gov (United States)

    Tarver, William J.

    2010-01-01

    Concerns about heart dysrhythmia have been present since the earliest days of the US manned space program. While information about an astronaut's health is general kept private, one of the original seven American astronaut's health status was played out in a very public forum. Donald "Deke" Slayton was removed from the second manned space flight when it was discovered he had idiopathic atrial fibrillation. Referencing the original medical documents, details of how this was discovered and managed from the medical perspective will be reviewed. This is NASA's first heart dysrhythmia case in an astronaut and it proves quite interesting when placed in historic perspective.

  11. Current approaches in atrial fibrillation treatment

    Directory of Open Access Journals (Sweden)

    Cenk Sarı

    2014-09-01

    Full Text Available Atrial fibrillation (AF is the most common sustained arrhythmia encountered in clinical practice. Its incidence increases with age. AF is classified into subtypes according to the duration and/or able to provide sinus rhytym. İnitially, patients should be evaluated for rhythm or rate control for appropriate treatment. Second stage of strategy aimed to investigate the feasibility of anticoagulation therapy. Recently, due to the progress made in treatment with rhythm control and anticoagulation therapy, either American or European guidelines have been renovated. These developments have taken place in the newly published guide. In this article, the current change in the management of AF is discussed.

  12. The polyuria of paroxysmal atrial tachycardia

    Science.gov (United States)

    Kinney, M. J.; Stein, R. M.; Discala, V. A.

    1974-01-01

    Two patients with paroxysmal atrial fibrillation and an associated polyuria were studied to delineate the mechanism of the increase in urine flow. A striking saluresis was noted in both patients. The increased sodium excretion was probably due to decreased sodium reabsorption, perhaps at proximal tubular nephron sites. This inhibition of sodium reabsorption could explain both the saluresis and some part or all of the polyuria. Re-evaluation of earlier case reports reveals patterns of concomitant salt and water excretion consistent with this mechanism. The saluresis cannot be explained by the previously favored hypothesis of antidiuretic hormone inhibition.

  13. Echocardiographic study of left atrial myxoma

    Directory of Open Access Journals (Sweden)

    Dalal J

    1979-01-01

    Full Text Available Four cases of left atrial myxoma were diagnosed pre-operatively by echocardiography. All cases showed characteristic echocardio-graphic features of variegated shadows behind the mitral valve in diastole and within the left atrium in systole. In two cases the my-xomas were surgically removed and confirmed on histology. In one case the post-operative echocardiogram showed complete dis-appearance of the abnormal shadows. Echocardiography is the most reliable method today for the diagnosis of a myxoma.

  14. Atrial overexpression of angiotensin-converting enzyme 2 improves the canine rapid atrial pacing-induced structural and electrical remodeling. Fan, ACE2 improves atrial substrate remodeling.

    Science.gov (United States)

    Fan, Jinqi; Zou, Lili; Cui, Kun; Woo, Kamsang; Du, Huaan; Chen, Shaojie; Ling, Zhiyu; Zhang, Quanjun; Zhang, Bo; Lan, Xianbin; Su, Li; Zrenner, Bernhard; Yin, Yuehui

    2015-01-01

    The purpose of this study was to investigate whether atrial overexpression of angiotensin-converting enzyme 2 (ACE2) by homogeneous transmural atrial gene transfer can reverse atrial remodeling and its mechanisms in a canine atrial-pacing model. Twenty-eight mongrel dogs were randomly divided into four groups: Sham-operated, AF-control, gene therapy with adenovirus-enhanced green fluorescent protein (Ad-EGFP) and gene therapy with Ad-ACE2 (Ad-ACE2) (n = 7 per subgroup). AF was induced in all dogs except the Sham-operated group by rapid atrial pacing at 450 beats/min for 2 weeks. Ad-EGFP and Ad-ACE2 group then received epicardial gene painting. Three weeks after gene transfer, all animals except the Sham group underwent rapid atrial pacing for another 3 weeks and then invasive electrophysiological, histological and molecular studies. The Ad-ACE2 group showed an increased ACE2 and Angiotensin-(1-7) expression, and decreased Angiotensin II expression in comparison with Ad-EGFP and AF-control group. ACE2 overexpression attenuated rapid atrial pacing-induced increase in activated extracellular signal-regulated kinases and mitogen-activated protein kinases (MAPKs) levels, and decrease in MAPK phosphatase 1(MKP-1) level, resulting in attenuation of atrial fibrosis collagen protein markers and transforming growth factor-β1. Additionally, ACE2 overexpression also modulated the tachypacing-induced up-regulation of connexin 40, down-regulation of connexin 43 and Kv4.2, and significantly decreased the inducibility and duration of AF. ACE2 overexpression could shift the renin-angiotensin system balance towards the protective axis, attenuate cardiac fibrosis remodeling associated with up-regulation of MKP-1 and reduction of MAPKs activities, modulate tachypacing-induced ion channels and connexin remodeling, and subsequently reduce the inducibility and duration of AF.

  15. Higher fractions theory of fractional hall effect

    International Nuclear Information System (INIS)

    Kostadinov, I.Z.; Popov, V.N.

    1985-07-01

    A theory of fractional quantum Hall effect is generalized to higher fractions. N-particle model interaction is used and the gap is expressed through n-particles wave function. The excitation spectrum in general and the mean field critical behaviour are determined. The Hall conductivity is calculated from first principles. (author)

  16. [Quantitative Measurements on the Blood Flow Fields of Left Atrial Appendage using Vector Flow Mapping in Patients with Nonvalvular Atrial Fibrillation].

    Science.gov (United States)

    Cai, Yu-Yan; Wei, Xin; Zhang, Xiao-Ling; Liu, Gu-Yue; Li, Xi; Tang, Hong

    2018-01-01

    To quantify the hemodynamic characteristics of patients with nonvalvular atrial fibrillation. Twenty patients with paroxysmal atrial fibrillation and 15 patients with persistent atrial fibrillation enrolled in this study,while 12 patients with sinus rhythms served as controls. The hemodynamic characteristics of the patients in left atrial appendage were measured by transesophageal echocardiography (TEE) and vector flow mapping (VFM) using indicators such as vectors,vortex and energy loss (EL). ① Significant differences appeared between the patients with atrial fibrillation and the controls in heart rate,size of left atrium,size of left atrial appendage (LAA),and velocities of LAA filling and emptying. ② Regular vectors in LAA in early systole and late diastole were found in the patients with paroxysmal atrial fibrillation and the controls; whereas,irregular vectors with direction alternating were visualized in the whole cardiac cycle in the patients with persistent atrial fibrillation. ③ Small vortexes were observed at the opening of the left atrial appendage in late diastole in the patients with paroxysmal atrial fibrillation and the controls. ④ Peak EL values occurred in early systole and late diastole in the patients with paroxysmal atrial fibrillation and the controls. But the patients with persistent atrial fibrillation had increased EL values over the whole cardiac cycle. VFM can visualize and quantify the hemodynamics of LAA in patients with different heart rhythms. It may provide a new method for assessing atrial fibrillation. CopyrightCopyright© by Editorial Board of Journal of Sichuan University (Medical Science Edition).

  17. Aortic properties and atrial electrophysiology in the young and old football players Propriedades da aorta e electrofisiologia atrial em futebolistas profissionais ativos e aposentados

    Directory of Open Access Journals (Sweden)

    Hakan Hasdemir

    2011-06-01

    Full Text Available OBJECTIVE: The purpose of this study was to investigate the differences between P wave dispersion, aortic elastic properties and transthoracic echocardiographic findings in the young and old football players compared to control groups in order to asses the influence of regular sportive activity on aortic distensibility and its potential effect on atrial electrophysiology. METHODS : We recruited 42 young football players with a training history of many years. The control group was formed by 27 healthy sedentary men. Twenty-three healthy retired football players of a professional football club aged over 50 years were included in the study as old group and 18 subjects over 50 year old who did not perform regular exercise when they were young were included in the control group of old subjects. RESULTS: The heart rate and ejection fraction were decreased in the young football players. There were no significant differences in the aortic elastic parameters and P wave dispersion between young football players and control group. But in old subjects with sustained participation in regular sportive activity, the significant difference of left ventricular dimension, wall thickness and systolic functions detected in the young group disappeared while increase in the left atrial diameter became significant. CONCLUSION: Potential effect of aortic elastic properties which changes with age, on atrial electrophysiology through increasing P wave dispersion was shown.OBJETIVO: Com este estudo pretendeu-se levar a cabo um ensaio clínico que permitisse investigar as diferenças entre a dispersão da onda P (DOP, as propriedades elásticas da aorta e os resultados da ecocardiografia transtorácica em futebolistas profissionais ativos e reformados, face a grupos de controle, de modo a avaliar a influência da atividade desportiva regular na distensibilidade aórtica e o seu potencial efeito na electrofisiologia atrial. MÉTODOS: Para este estudo foram recrutados 42

  18. Clinical characteristics, management, and control of permanent vs. nonpermanent atrial fibrillation: insights from the RealiseAF survey.

    LENUS (Irish Health Repository)

    Murin, Jan

    2014-01-01

    Atrial fibrillation can be categorized into nonpermanent and permanent atrial fibrillation. There is less information on permanent than on nonpermanent atrial fibrillation patients. This analysis aimed to describe the characteristics and current management, including the proportion of patients with successful atrial fibrillation control, of these atrial fibrillation subsets in a large, geographically diverse contemporary sample.

  19. Atrial Fibrillation Predictors: Importance of the Electrocardiogram.

    Science.gov (United States)

    German, David M; Kabir, Muammar M; Dewland, Thomas A; Henrikson, Charles A; Tereshchenko, Larisa G

    2016-01-01

    Atrial fibrillation (AF) is the most common arrhythmia in adults and is associated with significant morbidity and mortality. Substantial interest has developed in the primary prevention of AF, and thus the identification of individuals at risk for developing AF. The electrocardiogram (ECG) provides a wealth of information, which is of value in predicting incident AF. The PR interval and P wave indices (including P wave duration, P wave terminal force, P wave axis, and other measures of P wave morphology) are discussed with regard to their ability to predict and characterize AF risk in the general population. The predictive value of the QT interval, ECG criteria for left ventricular hypertrophy, and findings of atrial and ventricular ectopy are also discussed. Efforts are underway to develop models that predict AF incidence in the general population; however, at present, little information from the ECG is included in these models. The ECG provides a great deal of information on AF risk and has the potential to contribute substantially to AF risk estimation, but more research is needed. © 2015 Wiley Periodicals, Inc.

  20. Right atrial bypass model in the dog.

    Science.gov (United States)

    Breen, P H; Isserles, S A

    1995-02-01

    In gas exchange studies addressing the storage and transport of CO2 in dogs, a model in which cardiac output (QT) can be precisely controlled and measured would be beneficial. We identified problems with described extracorporeal circuits and implemented right atrial bypass (RAB) in dogs. In 6 anesthetized (chloralose and urethane), heparinized dogs (mean +/- SD, 24 +/- 4 kg) with open thorax, cannulas were inserted in both vena cavas to drain venous blood return to a reservoir (anaerobic bag or bubble oxygenator). A roller pump then drove blood through a heat exchanger back to the right atrial appendage. After 1.8 +/- 1.4 hour of RAB, physiologic variables remained within reference limits for dogs (QT, 1.5 +/- 0.3 L/min; blood pressure, 92 +/- 25 mm of Hg; arterial PCO2, 35 +/- 4 mm of Hg; PO2, 513 +/- 39 mm of Hg; pH, 7.39 +/- 0.08; and tissue CO2 production, 126 +/- 56 ml/min). To permit study of gas exchange, venous return (and thus, QT) and venous PCO2 and PO2 could be accurately regulated and measured over a wide range. Maintenance of native pulsatile lung perfusion and cardiogenic oscillations minimizes mismatching of pulmonary ventilation and perfusion and facilitates studies addressing pulmonary gas exchange. This RAB model is designed so that investigators can establish the preparation in a few hours.

  1. Pulmonary edema following transcatheter closure of atrial septal defect

    Directory of Open Access Journals (Sweden)

    Keerthi Chigurupati

    2015-01-01

    Full Text Available We describe an incident of development of acute pulmonary edema after the device closure of a secundum atrial septal defect in a 52-year-old lady, which was treated with inotropes, diuretics and artificial ventilation. Possibility of acute left ventricular dysfunction should be considered after the defect closure in the middle-aged patients as the left ventricular compliance may be reduced due to increased elastic stiffness and diastolic dysfunction. Baseline left atrial pressure may be > 10 mmHg in these patients. Associated risk factors for the left ventricular dysfunction are a large Qp:Qs ratio, systemic hypertension, severe pulmonary hypertension and paroxysmal atrial fibrillation.

  2. The immediate future for the medical treatment of atrial fibrillation

    DEFF Research Database (Denmark)

    Pedersen, Ole Dyg; Brendorp, Bente; Køber, Lars

    2002-01-01

    ) the rhythm causes loss of atrioventricular synchrony, which reduces diastolic filling and may lead to heart failure; and iii) atrial contraction is lost leading to stagnant blood that again may lead to atrial thrombi and peripheral embolism. Thus, the treatment of atrial fibrillation is focused...... on the maintenance of sinus rhythm, rate control and prevention of embolism. For the maintenance of sinus rhythm, all drugs under current development are potassium channel blockers; the so-called class III anti-arrhythmic drugs. Those which have been further investigated appear to be valuable for maintenance...

  3. Acute Pulmonary Edema Caused by a Giant Atrial Myxoma

    Directory of Open Access Journals (Sweden)

    Andrea Fisicaro

    2013-01-01

    Full Text Available Atrial myxoma is the most common primary cardiac tumor. Its clinical presentation spreads from asymptomatic incidental mass to serious life-threatening cardiovascular complications. We report the case of a 44-year-old man with evening fever and worsening dyspnea in the last weeks, admitted to our hospital for acute pulmonary edema. The cardiac auscultation was very suspicious for mitral valve stenosis, but the echocardiography revealed a huge atrial mass with a diastolic prolapse into mitral valve orifice causing an extremely high transmitral gradient pressure. Awareness of this uncommon acute presentation of atrial myxoma is necessary for timely diagnosis and prompt surgical intervention.

  4. Atrial Septal Aneurysm Presenting as Clubbing without Clinically Apparent Cyanosis.

    Science.gov (United States)

    Goyal, Laxmi Kant; Banerjee, S; Yadav, R N; Singh, Gajraj; Ganguli, Sujata; Isran, Rohit

    2015-09-01

    Atrial septal aneurysm (ASA) is a localised "saccular" deformity which protrudes to the right or the left atrium or on both sides. It is a rare, but well recognised cardiac abnormality. It is usually an incidental finding or may presents as atrial arrhythmias or arterial embolism. Though it is an acyanotic congenital heart disease but it may result in significant right to left shunt and cyanosis. We describe a patient of ASA with atrial septal defect who presented with clubbing and right to left shunt without clinically apparent cyanosis. © Journal of the Association of Physicians of India 2011.

  5. Atrial natriuretic peptide and feeding activity patterns in rats

    Directory of Open Access Journals (Sweden)

    Oliveira M.H.A.

    1997-01-01

    Full Text Available This review presents historical data about atrial natriuretic peptide (ANP from its discovery as an atrial natriuretic factor (ANF to its role as an atrial natriuretic hormone (ANH. As a hormone, ANP can interact with the hypothalamic-pituitary-adrenal axis (HPA-A and is related to feeding activity patterns in the rat. Food restriction proved to be an interesting model to investigate this relationship. The role of ANP must be understood within a context of peripheral and central interactions involving different peptides and pathways

  6. 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

    by Jakobsen and colleagues. We plan to include all relevant randomised clinical trials assessing the effects of any rhythm control strategy versus any rate control strategy. We plan to search the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, LILACS, Science Citation Index Expanded...... on Web of Science, and BIOSIS to identify relevant trials. Any eligible trial will be assessed and classified as either high risk of bias or low risk of bias, and our conclusions will be based on trials with low risk of bias. The analyses of the extracted data will be performed using Review Manager 5....... This protocol for a systematic review aims at identifying the best overall treatment strategy for atrial fibrillation and atrial flutter. METHODS: This protocol for a systematic review was performed following the recommendations of the Cochrane Collaboration and the eight-step assessment procedure suggested...

  7. Left Atrial Appendage Closure in Atrial Fibrillation: A World without Anticoagulation?

    Directory of Open Access Journals (Sweden)

    Tahmeed Contractor

    2011-01-01

    Full Text Available Atrial Fibrillation (AF is a common arrhythmia with an incidence that is as high as 10% in the elderly population. Given the large proportion of strokes caused by AF as well as the associated morbidity and mortality, reducing stroke burden is the most important part of AF management. While warfarin significantly reduces the risk of AF-related stroke, perceived bleeding risks and compliance limit its widespread use in the high-risk AF population. The left atrial appendage is believed to be the “culprit” for thrombogenesis in nonvalvular AF and is a new therapeutic target for stroke prevention. The purpose of this review is to explore the evolving field of percutaneous LAA occlusion. After briefly highlighting the risk of stroke with AF, problems with warfarin, and the role of the LAA in clot formation, this article discusses the feasibility and efficacy of various devices which have been developed for percutaneous LAA occlusion.

  8. Surface atrial frequency analysis in patients with atrial fibrillation: a tool for evaluating the effects of intervention.

    Science.gov (United States)

    Raine, Dan; Langley, Philip; Murray, Alan; Dunuwille, Asunga; Bourke, John P

    2004-09-01

    The aims of this study were to evaluate (1) principal component analysis as a technique for extracting the atrial signal waveform from the standard 12-lead ECG and (2) its ability to distinguish changes in atrial fibrillation (AF) frequency parameters over time and in response to pharmacologic manipulation using drugs with different effects on atrial electrophysiology. Twenty patients with persistent AF were studied. Continuous 12-lead Holter ECGs were recorded for 60 minutes, first, in the drug-free state. Mean and variability of atrial waveform frequency were measured using an automated computer technique. This extracted the atrial signal by principal component analysis and identified the main frequency component using Fourier analysis. Patients were then allotted sequentially to receive 1 of 4 drugs intravenously (amiodarone, flecainide, sotalol, or metoprolol), and changes induced in mean and variability of atrial waveform frequency measured. Mean and variability of atrial waveform frequency did not differ within patients between the two 30-minute sections of the drug-free state. As hypothesized, significant changes in mean and variability of atrial waveform frequency were detected after manipulation with amiodarone (mean: 5.77 vs 4.86 Hz; variability: 0.55 vs 0.31 Hz), flecainide (mean: 5.33 vs 4.72 Hz; variability: 0.71 vs 0.31 Hz), and sotalol (mean: 5.94 vs 4.90 Hz; variability: 0.73 vs 0.40 Hz) but not with metoprolol (mean: 5.41 vs 5.17 Hz; variability: 0.81 vs 0.82 Hz). A technique for continuously analyzing atrial frequency characteristics of AF from the surface ECG has been developed and validated.

  9. Asphalt chemical fractionation

    International Nuclear Information System (INIS)

    Obando P, Klever N.

    1998-01-01

    Asphalt fractionation were carried out in the Esmeraldas Oil Refinery using n-pentane, SiO 2 and different mixture of benzene- methane. The fractions obtained were analyzed by Fourier's Transformed Infrared Spectrophotometry (FTIR)

  10. Assessment of left atrial volume and function in patients with permanent atrial fibrillation

    DEFF Research Database (Denmark)

    Agner, Bue F Ross; Kühl, Jørgen Tobias; Linde, Jesper James

    2014-01-01

    Atrial fibrillation (AF) is a common cardiac arrhythmia that is associated with substantial morbidity and mortality. AF is associated with enlargement of the left atrium (LA), and the LA volume has important prognostic implications for the disease. The objective of the study was to determine how...... measurements of LA volume and function obtained by transthoracic echocardiography (TTE), cardiac magnetic resonance (CMR), and 320-slice multi-detector computed tomography (MDCT) correlate in patients with permanent AF....

  11. Three-dimensional atrial wall thickness maps to inform catheter ablation procedures for atrial fibrillation.

    Science.gov (United States)

    Bishop, Martin; Rajani, Ronak; Plank, Gernot; Gaddum, Nicholas; Carr-White, Gerry; Wright, Matt; O'Neill, Mark; Niederer, Steven

    2016-03-01

    Transmural lesion formation is critical to success in atrial fibrillation ablation and is dependent on left atrial wall thickness (LAWT). Pre- and peri-procedural planning may benefit from LAWT measurements. To calculate the LAWT, the Laplace equation was solved over a finite element mesh of the left atrium derived from the segmented computed tomographic angiography (CTA) dataset. Local LAWT was then calculated from the length of field lines derived from the Laplace solution that spanned the wall from the endocardium or epicardium. The method was validated on an atrium phantom and retrospectively applied to 10 patients who underwent routine coronary CTA for standard clinical indications at our institute. The Laplace wall thickness algorithm was validated on the left atrium phantom. Wall thickness measurements had errors of atrial wall thickness measurements were performed on 10 patients. Successful comprehensive LAWT maps were generated in all patients from the coronary CTA images. Mean LAWT measurements ranged from 0.6 to 1.0 mm and showed significant inter and intra patient variability. Left atrial wall thickness can be measured robustly and efficiently across the whole left atrium using a solution of the Laplace equation over a finite element mesh of the left atrium. Further studies are indicated to determine whether the integration of LAWT maps into pre-existing 3D anatomical mapping systems may provide important anatomical information for guiding radiofrequency ablation. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  12. Galectin-3 as a marker of interstitial atrial remodelling involved in atrial fibrillation

    OpenAIRE

    Diana Hernández-Romero; Juan Antonio Vílchez; Álvaro Lahoz; Ana I. Romero-Aniorte; Eva Jover; Arcadio García-Alberola; Rubén Jara-Rubio; Carlos M. Martínez; Mariano Valdés; Francisco Marín

    2017-01-01

    Remodelling in the atria could appear as a result of hypertension, diabetes or ischaemic heart disease. Galectin-3 (Gal-3) is a mediator of profibrotic pathways and a potential biomarker of cardiac remodelling. We prospectively recruited consecutive patients undergoing elective cardiac surgery. Preoperative Gal-3 levels were determined from serum samples, and the presence of fibrosis was assessed from atrial appendage tissue samples obtained during cardiac surgery. We included 100 patients wi...

  13. Development of a transgenic goat model wih cardiac-specific overexpression of transforming growth factor - {beta} 1 to study the relationship between atrial fibrosis and atrial fibrillation

    Science.gov (United States)

    Studies on patients, large animal models and transgenic mouse models have shown a strong association of atrial fibrosis with atrial fibrillation (AF). However, it is unclear whether there is a causal relationship between atrial fibrosis and AF or whether these events appear as a result of independen...

  14. Left atrial appendage thrombosis during therapy with rivaroxaban in elective cardioversion for permanent atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Walter Serra

    2015-09-01

    Full Text Available Electric external cardioversion (EEC for permanent atrial fibrillation (AF carries a risk of thromboembolic events (TE. The use of transesophageal echocardiography (TEE to guide the management of atrial fibrillation may be considered a clinically effective alternative strategy to conventional therapy for patients in whom elective cardioversion is planned. Therapeutic anticoagulation with novel oral anticoagulants (NOAC is recommended for 3 to 4 weeks before and an anticoagulation life-long therapy is recommended after EEC to reduce TE, in patients with high CHA2DS2-VASc score; however, only few data are currently available about safety of shortterm anticoagulation with NOAC in the setting of EEC. Patients with increased risk of thromboembolism have not been adequately studied and the monitoring of anticoagulant effects can also have important benefits in case of drug interactions. We report a case of a 68-year old man with AF from September 2014. Moderate depression of global left ventricular systolic function was detected by echocardiographic exam. On the basis of a high thromboembolic risk, an anticoagulant therapy with rivaroxaban, at the dose of 20 mg/day, was started. TEE showed a thrombus in the left atrial appendage. This case demonstrates the utility of performing TEE prior than EEC in patients with hypokinetic cardiomyopathy other than AF in therapy with NOAC. We underline the presence of significant pharmacodynamic interference of rivaroxaban with other drugs such as oxcarbazepine.

  15. Limitations of Dower's inverse transform for the study of atrial loops during atrial fibrillation.

    Science.gov (United States)

    Guillem, María S; Climent, Andreu M; Bollmann, Andreas; Husser, Daniela; Millet, José; Castells, Francisco

    2009-08-01

    Spatial characteristics of atrial fibrillatory waves have been extracted by using a vectorcardiogram (VCG) during atrial fibrillation (AF). However, the VCG is usually not recorded in clinical practice and atrial loops are derived from the 12-lead electrocardiogram (ECG). We evaluated the suitability of the reconstruction of orthogonal leads from the 12-lead ECG for fibrillatory waves in AF. We used the Physikalisch-Technische Bundesanstalt diagnostic ECG database, which contains 15 simultaneously recorded signals (12-lead ECG and three Frank orthogonal leads) of 13 patients during AF. Frank leads were derived from the 12-lead ECG by using Dower's inverse transform. Derived leads were then compared to true Frank leads in terms of the relative error achieved. We calculated the orientation of AF loops of both recorded orthogonal leads and derived leads and measured the difference in estimated orientation. Also, we investigated the relationship of errors in derivation with fibrillatory wave amplitude, frequency, wave residuum, and fit to a plane of the AF loops. Errors in derivation of AF loops were 68 +/- 31% and errors in the estimation of orientation were 35.85 +/- 20.43 degrees . We did not find any correlation among these errors and amplitude, frequency, or other parameters. In conclusion, Dower's inverse transform should not be used for the derivation of orthogonal leads from the 12-lead ECG for the analysis of fibrillatory wave loops in AF. Spatial parameters obtained after this derivation may differ from those obtained from recorded orthogonal leads.

  16. Correlation of right atrial appendage velocity with left atrial appendage velocity and brain natriuretic Peptide.

    Science.gov (United States)

    Kim, Bu-Kyung; Heo, Jung-Ho; Lee, Jae-Woo; Kim, Hyun-Soo; Choi, Byung-Joo; Cha, Tae-Joon

    2012-03-01

    Left atrial appendage (LAA) anatomy and function have been well characterized both in healthy and diseased people, whereas relatively little attention has been focused on the right atrial appendage (RAA). We sought to evaluate RAA flow velocity and to compare these parameters with LAA indices and with a study of biomarkers, such as brain natriuretic peptide, among patients with sinus rhythm (SR) and atrial fibrillation (AF). In a series of 79 consecutive patients referred for transesophageal echocardiography, 43 patients (23 with AF and 20 controls) were evaluated. AF was associated with a decrease in flow velocity for both LAA and RAA [LAA velocity-SR vs. AF: 61 ± 22 vs. 29 ± 18 m/sec (p vs. AF: 46 ± 20 vs. 19 ± 8 m/sec (p brain natriuretic peptide (BNP). AF was associated with decreased RAA and LAA flow velocities. RAA velocity was found to be positively correlated with LAA velocity and negatively correlated with BNP. The plasma BNP concentration may serve as a determinant of LAA and RAA functions.

  17. Smarandache Continued Fractions

    OpenAIRE

    Ibstedt, H.

    2001-01-01

    The theory of general continued fractions is developed to the extent required in order to calculate Smarandache continued fractions to a given number of decimal places. Proof is given for the fact that Smarandache general continued fractions built with positive integer Smarandache sequences baving only a finite number of terms equal to 1 is convergent. A few numerical results are given.

  18. Can preoperative serum level of creatinine predict new-onset atrial fibrillation in non-diabetic male patients undergoing open heart surgery? A retrograde view.

    Directory of Open Access Journals (Sweden)

    Seyed Jalil Mirhosseini

    2013-12-01

    Full Text Available Renal dysfunction is a risk marker in patients who candidate for coronary artery bypass graft (CABG. Renal disorder is associated with prolonged stays in intensive care unit and hospital, morbidity and mortality. Aim of this study is specific evaluation of association between preoperative creatinine (Cr with atrial fibrillation (AF after elective off-pump CABG in non-diabetic male patients with normal ejection fraction. Two hundred non-diabetic male patients with normal ejection fraction undergoing elective off pump CABG surgery enrolled in this cross-sectional study and were stratified by present or absence of postoperative atrial fibrillation: patients with postoperative new-onset atrial fibrillation (n=100 as group 1 and patients without new-onset postoperative atrial fibrillation as group 2 (n=100. Preoperative serological test of the participants, such as serum creatinine, were recorded in their medical dossiers. Data were analyzed in SPSS-16 software and tested for association between atrial fibrillation with creatinine level by using student t test, chi-square test or logistic regression. Cr level in patients with and without AF three days before surgery were 1.8±0.3 and 1.0±0.4 respectively (P value for Cr=0.00. On surgical day, mean Cr level in patients with and without AF were 1.6±0.2 and 1.1±0.5 respectively (P value for Cr = 0.00. Of the 100, male patients with postoperative AF, duration and frequency of recurrence of AF were not associated with Cr at three days before surgery and on surgical days (P>0.05. Patients with postoperative AF had unsuitable status of renal function compare to patients without AF; however, preoperative serum creatinine cannot associate with duration and frequency of recurrence of AF.

  19. Dabigatran use in Danish atrial fibrillation patients in 2011

    DEFF Research Database (Denmark)

    Sørensen, Rikke; Gislason, Gunnar; Torp-Pedersen, Christian Tobias

    2013-01-01

    Objective: Dabigatran was recently approved for anticoagulation in patients with atrial fibrillation (AF); data regarding real-world use, comparative effectiveness and safety are sparse. Design: Pharmacoepidemiological cohort study. Methods/settings: From nationwide registers, we identified...

  20. Women Sex Importance in Stroke Patients with Atrial Fibrillation

    Directory of Open Access Journals (Sweden)

    Cemile Handan Mısırlı

    2014-08-01

    Full Text Available OBJECTIVE: It was shown the differences in age, risk factors and treatment between women and men in stroke patients with atrial fibrillation METHODS: The stroke patients with atrial fibrillation who were hospitalized in our department at the last 2 years were seperated into 2 groups of aged above 75 and below 75, investigated with CHADS2 and CHA2DS2VASc scores and looked at the sex differences of women and men. RESULTS: Stroke ratio according to sex was statistically meaningful especially in women above the age of 75. Risc factors also were founded in elderly women and CHA2DS2VASc scores were higher in women than men so more anticoagulan treatment were begun. No differences were shown between sexes at lone atrial fibrillation and no treatment were begun. CONCLUSION: Women with atrial fibrillation had more risk factors, higher stroke rate and higher anticoagulation treatment.

  1. Atrial fibrillation in the dog: a review of eight cases

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, R. E. [Vet. Hospital, 34 New Dover Rd, Canterbury, Kent (United Kingdom)

    1984-07-01

    Eight cases of canine atrial fibrillation encountered in small animal practice are reported. Details are included of age, sex and breed, history and clinical signs, thoracic radiography, electrocardiography, clinical pathology, treatment and survival periods.

  2. Atrial fibrillation in the dog: a review of eight cases

    International Nuclear Information System (INIS)

    Thomas, R.E.

    1984-01-01

    Eight cases of canine atrial fibrillation encountered in small animal practice are reported. Details are included of age, sex and breed, history and clinical signs, thoracic radiography, electrocardiography, clinical pathology, treatment and survival periods

  3. Inflammation in the genesis and perpetuation of atrial fibrillation

    DEFF Research Database (Denmark)

    Engelmann, Mads D M; Svendsen, Jesper Hastrup

    2005-01-01

    The prevalence and persistence of atrial fibrillation (AF) and the relative inefficacy of the currently available pharmacotherapy requires development of new treatment strategies. Recent findings have suggested a mechanistic link between inflammatory processes and the development of AF...

  4. Long working hours as a risk factor for atrial fibrillation

    DEFF Research Database (Denmark)

    Kivimäki, Mika; Nyberg, Solja T.; Batty, G. David

    2017-01-01

    long hours (≤55 per week) and those working standard 35-40 h/week. Methods and results In this prospective multi-cohort study from the Individual-Participant-Data Meta-Analysis in Working Populations (IPD-Work) Consortium, the study population was 85 494 working men and women (mean age 43.4 years...... of atrial fibrillation (10-year cumulative incidence 12.4 per 1000). After adjustment for age, sex and socioeconomic status, individuals working long hours had a 1.4-fold increased risk of atrial fibrillation compared with those working standard hours (hazard ratio = 1.42, 95% CI= 1.13-1.80, P= 0......Aims Studies suggest that people who work long hours are at increased risk of stroke, but the association of long working hours with atrial fibrillation, the most common cardiac arrhythmia and a risk factor for stroke, is unknown. We examined the risk of atrial fibrillation in individuals working...

  5. Paroxysmal atrial fibrillation occurs often in cryptogenic ischaemic stroke

    DEFF Research Database (Denmark)

    Christensen, L M; Krieger, D W; Højberg, S

    2014-01-01

    BACKGROUND AND PURPOSE: Atrial fibrillation (AF) increases the risk of stroke fourfold and is associated with a poor clinical outcome. Despite work-up in compliance with guidelines, up to one-third of patients have cryptogenic stroke (CS). The prevalence of asymptomatic paroxysmal atrial fibrilla......BACKGROUND AND PURPOSE: Atrial fibrillation (AF) increases the risk of stroke fourfold and is associated with a poor clinical outcome. Despite work-up in compliance with guidelines, up to one-third of patients have cryptogenic stroke (CS). The prevalence of asymptomatic paroxysmal atrial...... lasting predominantly between 1 and 4 h. Four recurrent strokes were observed, three in patients with PAF; all three patients were on oral anticoagulation (OAC). CONCLUSIONS: One in five patients with CS had PAF, which occurred at low burden and long after stroke. Future studies should determine the role...

  6. Dronedarone in high-risk permanent atrial fibrillation

    DEFF Research Database (Denmark)

    Connolly, Stuart J; Camm, A John; Halperin, Jonathan L

    2011-01-01

    Dronedarone restores sinus rhythm and reduces hospitalization or death in intermittent atrial fibrillation. It also lowers heart rate and blood pressure and has antiadrenergic and potential ventricular antiarrhythmic effects. We hypothesized that dronedarone would reduce major vascular events in ...

  7. Atrial angioleiomyoma with myopericytoma-like features: a case report.

    Science.gov (United States)

    Nassereddine, Hussein; Cazes, Aurélie; Verdonk, Constance; Assous, Benjamin; Dautry, Raphael; Nataf, Patrick; Wassef, Michel; Deschamps, Lydia

    A 66-year-old female patient was referred to our hospital for resection of a right atrial mass. Four months earlier, she had suffered an acute cerebrovascular accident due to occlusion of the sylvian segment of the right middle cerebral artery from atheromatous tight stenosis in the right internal carotid artery. Later, investigations with transthoracic and transesophageal echocardiography revealed a 3.4-cm right atrial mass that was resected surgically. Microscopic evaluation revealed a well-circumscribed nodular tumor, located within the interatrial septum, and corresponding to an angioleiomyoma (ALM). This tumor differs histologically from atrial myxoma. ALM is a ubiquitous benign tumor but has never been reported to occur in the atrium. ALM can mimic cardiac myxoma and should be considered in the differential diagnosis of atrial tumors. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Fractional smith chart theory

    KAUST Repository

    Shamim, Atif

    2011-03-01

    For the first time, a generalized Smith chart is introduced here to represent fractional order circuit elements. It is shown that the standard Smith chart is a special case of the generalized fractional order Smith chart. With illustrations drawn for both the conventional integer based lumped elements and the fractional elements, a graphical technique supported by the analytical method is presented to plot impedances on the fractional Smith chart. The concept is then applied towards impedance matching networks, where the fractional approach proves to be much more versatile and results in a single element matching network for a complex load as compared to the two elements in the conventional approach. © 2010 IEEE.

  9. Anatomic characterization of cavotricuspid isthmus by 3D transesophageal echocardiography in patients undergoing radiofrequency ablation of typical atrial flutter.

    Science.gov (United States)

    Regoli, François; Faletra, Francesco; Marcon, Serena; Leo, Laura Anna; Dequarti, Maria Cristina; Caputo, Maria Luce; Conte, Giulio; Moccetti, Tiziano; Auricchio, Angelo

    2018-01-01

    Radiofrequency ablation (RFA) is the treatment of choice of cavotricuspid isthmus (CTI)-dependent atrial flutter. Procedural time is highly variable due to anatomical structures. This study aimed to characterize CTI anatomy by transesophageal 3D echocardiography imaging (3D-TEE) to identify anatomic structures related to longer ablation time. Thirty-one consecutive patients (mean age 67.3 ± 11.5 years, 22 males) underwent CTI-ablation procedure. Before ablation, TEE was performed and 3D-TEE images were acquired to evaluate CTI anatomy qualitatively as well as perform measures of CTI morphological features. The electrophysiologist performing RFA was blinded to 3D-TEE data. Bidirectional block of CTI was achieved in all patients without procedural complications after a median ablation time of 11 (IQR 7-14) min. Patients with RFA time ≥11 min (Group 2) presented lower left ventricular ejection fraction (51.1 ± 17.0 vs. 59.5 ± 6.6%, P 3D-TEE imaging is extremely helpful in qualitative and quantitative evaluation of CTI anatomy in patients undergoing RFA for symptomatic typical atrial flutter. Detection of a deep right atrial pouch was found to be associated with significantly prolonged CTI ablation time to achieve bidirectional block. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

  10. Stroke and bleeding in atrial fibrillation with chronic kidney disease

    DEFF Research Database (Denmark)

    Olesen, Jonas Bjerring; Lip, Gregory Y.H.; Kamper, Anne-Lise

    2012-01-01

    Both atrial fibrillation and chronic kidney disease increase the risk of stroke and systemic thromboembolism. However, these risks, and the effects of antithrombotic treatment, have not been thoroughly investigated in patients with both conditions.......Both atrial fibrillation and chronic kidney disease increase the risk of stroke and systemic thromboembolism. However, these risks, and the effects of antithrombotic treatment, have not been thoroughly investigated in patients with both conditions....

  11. Three-dimensional transesophageal echocardiography of the atrial septal defects

    Directory of Open Access Journals (Sweden)

    Romero-Cárdenas Ángel

    2008-07-01

    Full Text Available Abstract Transesophageal echocardiography has advantages over transthoracic technique in defining morphology of atrial structures. Even though real time three-dimensional echocardiographic imaging is a reality, the off-line reconstruction technique usually allows to obtain higher spatial resolution images. The purpose of this study was to explore the accuracy of off-line three-dimensional transesophageal echocardiography in a spectrum of atrial septal defects by comparing them with representative anatomic specimens.

  12. Aorto-right atrial fistula after Bentall repair.

    Science.gov (United States)

    Howard, Charles E; Velasco, Carlos E; Roullard, Christina P; Rafael, Aldo

    2017-07-01

    We describe a man with the Marfan syndrome and a prior ascending aortic aneurysm resection who presented with knee pain and concern of endocarditis. Transesophageal echocardiogram showed no vegetations, and computed tomography angiogram of the heart showed a possible pseudoaneurysm. Cardiac catheterization and aortogram revealed the diagnosis of an aorto-right atrial fistula, which was then operatively repaired. This case highlights the role that cardiac catheterization with aortogram can play in the detection of aorto-atrial fistula.

  13. Vernakalant hydrochloride for the treatment of atrial fibrillation.

    Science.gov (United States)

    Kozlowski, Dariusz; Budrejko, Szymon; Lip, Gregory Y H; Mikhailidis, Dimitri P; Rysz, Jacek; Raczak, Grzegorz; Banach, Maciej

    2009-12-01

    Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice. Rhythm control strategy for AF is limited by drug toxicity and side effects, and recent trials have shown that this strategy is not superior to a rate control one. New antiarrhythmic drugs, free of undesired effects, would enhance rhythm control, with the possibility of sinus rhythm restoration and maintenance. A promising find in the search for new antiarrhythmic therapies is atrial-tissue specific ion channels. The findings that the ultrarapid delayed rectifier (I(Kur)) and the inwardly rectifying, acetylcholine-regulated current (I(K-Ach)) exist in atrial but not ventricular tissue increase the probability that atrioselective drugs without ventricular proarrhythmic toxicity can be developed for treatment of patients with AF. There are also other potential targets for atrial-selective therapy: transient outward current (I(to)), rapidly and slowly activating delayed rectifier currents (I(Kr) and I(Ks)), atrial sodium current (I(Na)) and atrially expressed connexins. New drugs under development with promising atrial-selectivity include: tertiapin, NIP-142, NIP-141, JTV-519, AVE0118, AVE1231, DPO-1, AZD7009 and many others. Among such new agents, vernakalant hydrochloride is currently in an advanced phase of development and has already been evaluated in clinical trials. In this overview, we describe the history and current state of developmental process of the drug, as well as its mechanism of action and influence on electrophysiological parameters. Vernakalant seems to be effective in terminating recent-onset AF, but is not efficacious in long-lasting AF and atrial flutter. The drug may be relatively free of proarrhythmic effects, and exerts a protective effect on ventricular tissue and ventricular repolarization. It is expected that the intravenous formulation will soon be approved for the pharmacological termination of recent-onset AF.

  14. Nephroblastoma with right atrial extension: preoperative diagnosis and management.

    Science.gov (United States)

    Vaughan, E D; Crosby, I K; Tegtmeyer, C J

    1977-04-01

    A 14-year-old black boy, with a large nephroblastoma of the right kidney, had preoperative identification of inferior vena cava and right atrial involvement. Renal arteriography revealed linear arterial channels in the anatomic distribution of the inferior vena cava and venography revealed total caval occlusion and a right atrial mass. Radical excision, using a cardiopulmonary bypass, resulted in a 6-month postoperative survival.

  15. A new therapeutic strategy for electrical cardioversion of atrial fibrillation.

    Science.gov (United States)

    de Luca, I; Sorino, M; Del Salvatore, B; de Luca, L

    2001-11-01

    The conventional approach to cardioversion of atrial fibrillation includes a period of anticoagulation with oral anticoagulant therapy (OAT) extending from 3 weeks precardioversion to 4 weeks postcardioversion. The protocol of rapid anticoagulation (such as that of the ACUTE study) consists of a precardioversion transesophageal echocardiography (TEE) followed by OAT for 4 weeks. In the last few years low-molecular-weight heparins have established themselves as a safe and efficacious alternative to traditional antithrombotic therapies. The aim of this study was to demonstrate that the exclusion of thrombi by precardioversion TEE together with the exclusion of atrial stunning by a second TEE performed after 1 week, to date not suggested in the literature, could reduce to 7 days the period of pericardioversion anticoagulation. This therapy would be carried out using low-molecular-weight heparins with no need for biological monitoring and with the possibility of self-administration. We have studied 57 consecutive patients who had atrial fibrillation or flutter with a history of atrial fibrillation lasting > 48 hours. All patients received enoxaparin at a dosage of 100 IU antiXa/kg twice daily before undergoing multiplane TEE. Previous informed consent and ethical committee authorization had been obtained. Twenty-four hours following TEE, in the absence of thrombi and/or spontaneous moderate/severe echocontrast in the atrial chambers, the patients underwent electrical cardioversion and were discharged within 24 hours of sinus rhythm restoration. These patients were prescribed enoxaparin at the indicated dosage twice daily until TEE, performed in an outpatients setting 7 days following cardioversion. In the absence of thrombi and/or atrial and/or left atrial appendage stunning, OAT was terminated. Enoxaparin was associated with OAT for the following 3 weeks if any of the following signs of stunning were present: A wave inferior to the normal value for age at transmitral

  16. Late bacterial endocarditis of an Amplatzer atrial septal device

    Directory of Open Access Journals (Sweden)

    Bhavith Aruni

    2013-07-01

    Full Text Available A 59-year-old male with an secundum atrial septal defect status post repair with an Amplatzer occluder in 2001 was admitted with sepsis and MRSA bacteremia. Transesophageal Echocardiography (TEE showed presence of an overlying mobile echogenic structure on the left atrial surface of the device suggestive of a vegetation/infected thrombus. This is only the 3rd case description of late endocarditis involving the Amplatzer ASD closure device in an adult.

  17. Attitudes Towards Catheter Ablation for Atrial Fibrillation

    DEFF Research Database (Denmark)

    Vadmann, Henrik; Pedersen, Susanne S; Nielsen, Jens Cosedis

    2015-01-01

    BACKGROUND: Catheter ablation for atrial fibrillation (AF) is an important but expensive procedure that is the subject of some debate. Physicians´ attitudes towards catheter ablation may influence promotion and patient acceptance. This is the first study to examine the attitudes of Danish...... cardiologists towards catheter ablation for AF, using a nationwide survey. METHODS AND RESULTS: We developed a purpose-designed questionnaire to evaluate attitudes towards catheter ablation for AF that was sent to all Danish cardiologists (n = 401; response n = 272 (67.8%)). There was no association between...... attitudes towards ablation and the experience or age of the cardiologist with respect to patients with recurrent AF episodes with a duration of 7 days and/or need for cardioversion. The majority (69%) expected a recurrence of AF after catheter ablation in more than 30% of the cases...

  18. Advances in Imaging for Atrial Fibrillation Ablation

    International Nuclear Information System (INIS)

    D'Silva, A.; Wright, M.; Wright, M.

    2011-01-01

    Over the last fifteen years, our understanding of the pathophysiology of atrial fibrillation (AF) has paved the way for ablation to be utilized as an effective treatment option. With the aim of gaining more detailed anatomical representation, advances have been made using various imaging modalities, both before and during the ablation procedure, in planning and execution. Options have flourished from procedural fluoroscopy, electro anatomic mapping systems, pre procedural computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, and combinations of these technologies. Exciting work is underway in an effort to allow the electro physiologist to assess scar formation in real time. One advantage would be to lessen the learning curve for what are very complex procedures. The hope of these developments is to improve the likelihood of a successful ablation procedure and to allow more patients access to this treatment

  19. Alcohol and Atrial Fibrillation: A Sobering Review.

    Science.gov (United States)

    Voskoboinik, Aleksandr; Prabhu, Sandeep; Ling, Liang-Han; Kalman, Jonathan M; Kistler, Peter M

    2016-12-13

    Alcohol is popular in Western culture, supported by a perception that modest intake is cardioprotective. However, excessive drinking has detrimental implications for cardiovascular disease. Atrial fibrillation (AF) following an alcohol binge or the "holiday heart syndrome" is well characterized. However, more modest levels of alcohol intake on a regular basis may also increase the risk of AF. The pathophysiological mechanisms responsible for the relationship between alcohol and AF may include direct toxicity and alcohol's contribution to obesity, sleep-disordered breathing, and hypertension. We aim to provide a comprehensive review of the epidemiology and pathophysiology by which alcohol may be responsible for AF and determine whether alcohol abstinence is required for patients with AF. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  20. Fractional factorial plans

    CERN Document Server

    Dey, Aloke

    2009-01-01

    A one-stop reference to fractional factorials and related orthogonal arrays.Presenting one of the most dynamic areas of statistical research, this book offers a systematic, rigorous, and up-to-date treatment of fractional factorial designs and related combinatorial mathematics. Leading statisticians Aloke Dey and Rahul Mukerjee consolidate vast amounts of material from the professional literature--expertly weaving fractional replication, orthogonal arrays, and optimality aspects. They develop the basic theory of fractional factorials using the calculus of factorial arrangements, thereby providing a unified approach to the study of fractional factorial plans. An indispensable guide for statisticians in research and industry as well as for graduate students, Fractional Factorial Plans features: * Construction procedures of symmetric and asymmetric orthogonal arrays. * Many up-to-date research results on nonexistence. * A chapter on optimal fractional factorials not based on orthogonal arrays. * Trend-free plans...

  1. Fractional Dynamics and Control

    CERN Document Server

    Machado, José; Luo, Albert

    2012-01-01

    Fractional Dynamics and Control provides a comprehensive overview of recent advances in the areas of nonlinear dynamics, vibration and control with analytical, numerical, and experimental results. This book provides an overview of recent discoveries in fractional control, delves into fractional variational principles and differential equations, and applies advanced techniques in fractional calculus to solving complicated mathematical and physical problems.Finally, this book also discusses the role that fractional order modeling can play in complex systems for engineering and science. Discusses how fractional dynamics and control can be used to solve nonlinear science and complexity issues Shows how fractional differential equations and models can be used to solve turbulence and wave equations in mechanics and gravity theories and Schrodinger’s equation  Presents factional relaxation modeling of dielectric materials and wave equations for dielectrics  Develops new methods for control and synchronization of...

  2. Disease management: atrial fibrillation and home monitoring.

    Science.gov (United States)

    Ricci, Renato Pietro

    2013-06-01

    Device-detected atrial fibrillation (AF) episodes predict poor clinical outcome regardless of symptoms. Potential benefits of remote monitoring are early arrhythmia detection and patient continuous monitoring. Several studies of device remote monitoring consistently demonstrated that AF represents the most common clinical alert and that detailed information on arrhythmia onset, duration, and burden as well as on the ventricular rate may be early available for clinical evaluation. Reaction time to AF alerts was very short in all series involving either pacemakers or defibrillators and action ability of AF alerts was very high. In the Home Guide Registry, in which 1650 patients were enrolled, AF was detected in 16.3% of patients and represented 36% of all cardiovascular events during the follow-up. Timely anticoagulation introduction in asymptomatic patients may impact on the stroke rate. According to the results of repeated Monte Carlo simulations based on a real population of 166 patients, daily monitoring may reduce the 2-year stroke risk by 9-18% with an absolute reduction of 0.2-0.6%, compared with conventional inter-visit intervals of 6-12 months. In the COMPAS trial, the incidence of hospitalizations for atrial arrhythmias and related stroke was significantly higher in the control group than in the remote monitoring group. Major questions will be addressed by the ongoing IMPACT trial in which a remote monitoring guided anticoagulation strategy based on AF detection will be compared with a physician-directed standard strategy. In patients with heart failure, AF early detection combined with other indexes may help prevent hospitalizations.

  3. Calcium signalling silencing in atrial fibrillation.

    Science.gov (United States)

    Greiser, Maura

    2017-06-15

    Subcellular calcium signalling silencing is a novel and distinct cellular and molecular adaptive response to rapid cardiac activation. Calcium signalling silencing develops during short-term sustained rapid atrial activation as seen clinically during paroxysmal atrial fibrillation (AF). It is the first 'anti-arrhythmic' adaptive response in the setting of AF and appears to counteract the maladaptive changes that lead to intracellular Ca 2+ signalling instability and Ca 2+ -based arrhythmogenicity. Calcium signalling silencing results in a failed propagation of the [Ca 2+ ] i signal to the myocyte centre both in patients with AF and in a rabbit model. This adaptive mechanism leads to a substantial reduction in the expression levels of calcium release channels (ryanodine receptors, RyR2) in the sarcoplasmic reticulum, and the frequency of Ca 2+ sparks and arrhythmogenic Ca 2+ waves remains low. Less Ca 2+ release per [Ca 2+ ] i transient, increased fast Ca 2+ buffering strength, shortened action potentials and reduced L-type Ca 2+ current contribute to a substantial reduction of intracellular [Na + ]. These features of Ca 2+ signalling silencing are distinct and in contrast to the changes attributed to Ca 2+ -based arrhythmogenicity. Some features of Ca 2+ signalling silencing prevail in human AF suggesting that the Ca 2+ signalling 'phenotype' in AF is a sum of Ca 2+ stabilizing (Ca 2+ signalling silencing) and Ca 2+ destabilizing (arrhythmogenic unstable Ca 2+ signalling) factors. Calcium signalling silencing is a part of the mechanisms that contribute to the natural progression of AF and may limit the role of Ca 2+ -based arrhythmogenicity after the onset of AF. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

  4. Beat-to-beat assessment of left ventricular ejection in atrial fibrillation

    Energy Technology Data Exchange (ETDEWEB)

    Benjelloun, H; Brochier, M; Itti, R; Philippe, L; Lorgeron, J M

    1983-05-01

    Beat-to-beat left ventricular ejection was evaluated in a group of 20 patients with chronic atrial fibrillation using a computerized single probe detector. The reference group consisted of 10 patients with sinus rhythm. For each patient 30 successive cardiac cycles were analyzed and the relative variations of four parameters were assessed: R-R interval, diastolic and systolic time intervals, and ejection amplitude, corresponding to the left ventricular stroke volume. The mean variations were respectively 3.4%, 10.4%, 8.4%, and 11.8% in patients with sinus rhythm, and 21.9%, 37.9%, 10.6% and 30.5% in patients with artrial fibrillation. This demonstrates that changes in ejection are mainly related to the duration of the filling phase, with nearly constant systolic times. Correlations between R-R intervals and systolic ejection amplitudes were highly significant (P<0.001) in patients with atrial fibrillation in 85% of cases. This information complements the average ejection fraction obtained from multiple cycle superimposition.

  5. Impact of atrial fibrillation on the cardiovascular system through a lumped-parameter approach.

    Science.gov (United States)

    Scarsoglio, Stefania; Guala, Andrea; Camporeale, Carlo; Ridolfi, Luca

    2014-11-01

    Atrial fibrillation (AF) is the most common arrhythmia affecting millions of people in the Western countries and, due to the widespread impact on the population and its medical relevance, is largely investigated in both clinical and bioengineering sciences. However, some important feedback mechanisms are still not clearly established. The present study aims at understanding the global response of the cardiovascular system during paroxysmal AF through a lumped-parameter approach, which is here performed paying particular attention to the stochastic modeling of the irregular heartbeats and the reduced contractility of the heart. AF can be here analyzed by means of a wide number of hemodynamic parameters and avoiding the presence of other pathologies, which usually accompany AF. Reduced cardiac output with correlated drop of ejection fraction and decreased amount of energy converted to work by the heart during blood pumping, as well as higher left atrial volumes and pressures are some of the most representative results aligned with the existing clinical literature and here emerging during acute AF. The present modeling, providing new insights on cardiovascular variables which are difficult to measure and rarely reported in literature, turns out to be an efficient and powerful tool for a deeper comprehension and prediction of the arrythmia impact on the whole cardiovascular system.

  6. Beat-to-beat assessment of left ventricular ejection in atrial fibrillation

    International Nuclear Information System (INIS)

    Benjelloun, H.; Brochier, M.; Itti, R.; Philippe, L.; Lorgeron, J.M.

    1983-01-01

    Beat-to-beat left ventricular ejection was evaluated in a group of 20 patients with chronic atrial fibrillation using a computerized single probe detector. The reference group consisted of 10 patients with sinus rhythm. For each patient 30 successive cardiac cycles were analyzed and the relative variations of four parameters were assessed: R-R interval, diastolic and systolic time intervals, and ejection amplitude, corresponding to the left ventricular stroke volume. The mean variations were respectively 3.4%, 10.4%, 8.4%, and 11.8% in patients with sinus rhythm, and 21.9%, 37.9%, 10.6% and 30.5% in patients with artrial fibrillation. This demonstrates that changes in ejection are mainly related to the duration of the filling phase, with nearly constant systolic times. Correlations between R-R intervals and systolic ejection amplitudes were highly significant (P<0.001) in patients with atrial fibrillation in 85% of cases. This information complements the average ejection fraction obtained from multiple cycle superimposition. (orig.)

  7. Risk factors for persistent atrial fibrillation following successful hyperthyroidism treatment with radioiodine therapy.

    Science.gov (United States)

    Zhou, Zhen-Hu; Ma, Long-Le; Wang, Le-Xin

    2011-01-01

    To investigate the predicting factors for persistent atrial fibrillation (AF) following radioiodine therapy for hyperthyroidism. Standard 12-lead ECG and 24-h Holter monitoring were performed in 94 patients (38 males, mean age 46.1±8.2 years) with persistent AF following radioiodine therapy for hyperthyroidism. Left ventricular (LV) function was assessed with two-dimensional echocardiography. Euthyroidism or hypothyroidism was achieved in 81% and 19% of the patients, respectively, after radioiodine therapy. At the end of follow-up (1.6±1.3 years), LV ejection fraction in the 52 patients with LV dysfunction was increased from 39.3±3.3% to 59.0±5.5% (ptreatment paroxysmal AF, no AF was documented during the follow-up. In the 45 patients with pre-treatment persistent AF, AF was found in 27 (60%) during the follow-up. Multivariate logistic regression analysis showed that more than 55 years old in age (RR 2.76, 95% CI: 1.16-8.79, phyperthyroidism (RR 3.08, 95% CI: 1.22-11.41, ptreatment atrial fibrillation (RR 2.96, 95% CI: 1.31-7.68, phyperthyroidism and pre-treatment duration of AF are risk factors for persistent AF following radioiodine therapy.

  8. Vitamin D and new-onset atrial fibrillation: A meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Huang, Wei-Ling; Yang, Jun; Yang, Jian; Wang, Hui-Bo; Yang, Chao-Jun; Yang, Ying

    2017-11-14

    Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, which affects 1.5% to 2% of the general population. More than six million Europeans suffer from AF. To research vitamin D levels in the prevention of new-onset atrial fibrillation (AF), we conducted a systematic review of randomized controlled trials (RCTs). We focused on the vitamin D levels in the prevention of new-onset AF. The outcomes assessed were vitamin D levels, left ventricular ejection fraction (LVEF), and left atrium diameter. Six RCTs ultimately met the inclusion criteria in the meta-analysis. The outcomes of Vitamin D levels (MD = -4.27, 95% CI = -5.20 to-3.34, P = 0.30) in the new-onset AF showed no significant difference. The left atrium diameter (MD = 1.96, 95% CI = 1.48 to 2.60, P new-onset AF and LVEF (MD = -0.92, 95% CI = -1.59 to -0.26, P new-onset AF. Copyright © 2017 Hellenic Society of Cardiology. Published by Elsevier B.V. All rights reserved.

  9. Molecular Mechanisms and New Treatment Paradigm for Atrial Fibrillation.

    Science.gov (United States)

    Sirish, Padmini; Li, Ning; Timofeyev, Valeriy; Zhang, Xiao-Dong; Wang, Lianguo; Yang, Jun; Lee, Kin Sing Stephen; Bettaieb, Ahmed; Ma, Sin Mei; Lee, Jeong Han; Su, Demetria; Lau, Victor C; Myers, Richard E; Lieu, Deborah K; López, Javier E; Young, J Nilas; Yamoah, Ebenezer N; Haj, Fawaz; Ripplinger, Crystal M; Hammock, Bruce D; Chiamvimonvat, Nipavan

    2016-05-01

    Atrial fibrillation represents the most common arrhythmia leading to increased morbidity and mortality, yet, current treatment strategies have proven inadequate. Conventional treatment with antiarrhythmic drugs carries a high risk for proarrhythmias. The soluble epoxide hydrolase enzyme catalyzes the hydrolysis of anti-inflammatory epoxy fatty acids, including epoxyeicosatrienoic acids from arachidonic acid to the corresponding proinflammatory diols. Therefore, the goal of the study is to directly test the hypotheses that inhibition of the soluble epoxide hydrolase enzyme can result in an increase in the levels of epoxyeicosatrienoic acids, leading to the attenuation of atrial structural and electric remodeling and the prevention of atrial fibrillation. For the first time, we report findings that inhibition of soluble epoxide hydrolase reduces inflammation, oxidative stress, atrial structural, and electric remodeling. Treatment with soluble epoxide hydrolase inhibitor significantly reduces the activation of key inflammatory signaling molecules, including the transcription factor nuclear factor κ-light-chain-enhancer, mitogen-activated protein kinase, and transforming growth factor-β. This study provides insights into the underlying molecular mechanisms leading to atrial fibrillation by inflammation and represents a paradigm shift from conventional antiarrhythmic drugs, which block downstream events to a novel upstream therapeutic target by counteracting the inflammatory processes in atrial fibrillation. © 2016 American Heart Association, Inc.

  10. 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.

  11. Biomarkers of Atrial Cardiopathy and Atrial Fibrillation Detection on Mobile Outpatient Continuous Telemetry After Embolic Stroke of Undetermined Source.

    Science.gov (United States)

    Sebasigari, Denise; Merkler, Alexander; Guo, Yang; Gialdini, Gino; Kummer, Benjamin; Hemendinger, Morgan; Song, Christopher; Chu, Antony; Cutting, Shawna; Silver, Brian; Elkind, Mitchell S V; Kamel, Hooman; Furie, Karen L; Yaghi, Shadi

    2017-06-01

    Biomarkers of atrial dysfunction or "cardiopathy" are associated with embolic stroke risk. However, it is unclear if this risk is mediated by undiagnosed paroxysmal atrial fibrillation or flutter (AF). We aim to determine whether atrial cardiopathy biomarkers predict AF on continuous heart-rhythm monitoring after embolic stroke of undetermined source (ESUS). This was a single-center retrospective study including all patients with ESUS undergoing 30 days of ambulatory heart-rhythm monitoring to look for AF between January 1, 2013 and December 31, 2015. We reviewed medical records for clinical, radiographic, and cardiac variables. The primary outcome was a new diagnosis of AF detected during heart-rhythm monitoring. The primary predictors were atrial biomarkers: left atrial diameter on echocardiography, P-wave terminal force in electrocardiogram (ECG) lead V1, and P wave - R wave (PR) interval on ECG. A multiple logistic regression model was used to assess the relationship between atrial biomarkers and AF detection. Among 196 eligible patients, 23 (11.7%) were diagnosed with AF. In unadjusted analyses, patients with AF were older (72.4 years versus 61.4 years, P atrial diameter (39.2 mm versus 35.7 mm, P = .03). In a multivariable model, the only predictor of AF was age ≥ 60 years (odds ratio, 3.0; 95% CI, 1.06-8.5; P = .04). Atrial biomarkers were weakly associated with AF after ESUS. This suggests that previously reported associations between these markers and stroke may reflect independent cardiac pathways leading to stroke. Prospective studies are needed to investigate these mechanisms. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  12. Dividing Fractions: A Pedagogical Technique

    Science.gov (United States)

    Lewis, Robert

    2016-01-01

    When dividing one fraction by a second fraction, invert, that is, flip the second fraction, then multiply it by the first fraction. To multiply fractions, simply multiply across the denominators, and multiply across the numerators to get the resultant fraction. So by inverting the division of fractions it is turned into an easy multiplication of…

  13. Observation of the efficacy of radiofrequency catheter ablation on patients with different forms of atrial fibrillation.

    Science.gov (United States)

    Zhao, R-C; Han, W; Han, J; Yu, J; Guo, J; Fu, J-L; Li, Z; Zhao, R-Z

    2016-10-01

    To study the efficacy and safety of radiofrequency catheter ablation (RFCA) in patients with different forms of atrial fibrillation. By retrospective analysis, we summarize 720 cases, where patients diagnosed with atrial fibrillation in our hospital were treated with RFCA from February 2010 to October 2014. Among the cases, 425 were diagnosed with paroxysmal atrial fibrillation and 295 with non-paroxysmal atrial fibrillation (including persistent atrial fibrillation and permanent atrial fibrillation). All patients were followed up until June 2015 to compare and analyze the differences in operation success rates, complications and recurrence rates. 395 cases (92.9%) of paroxysmal atrial fibrillation and 253 cases (85.8%) with non-paroxysmal atrial fibrillation were subject to surgery and followed up. The age of onset, disease course, underlying diseases, left atrial diameter and combined anti-arrhythmics of patients with paroxysmal atrial fibrillation were lower than those of patients with non-paroxysmal atrial fibrillation, and the differences were statistically significant (p success rate of the first ablation was higher than that of non-paroxysmal atrial fibrillation. Procedure time, procedure method, complications and recurrence rate of patients with paroxysmal atrial fibrillation were lower than those of non-paroxysmal atrial fibrillation group, and the differences were statistically significant (p failure caused by atrial fibrillation in the two groups, the difference was not statistically significant (Apoplexy: p = 0.186; Heart failure: p = 0.170). The individual ablation success rate was higher for paroxysmal atrial fibrillation, and long-term follow-up showed that the occurrence of apoplexy and heart failure was not different from the non-paroxysmal atrial fibrillation group.

  14. Left atrial volume and function in dogs with naturally occurring myxomatous mitral valve disease

    DEFF Research Database (Denmark)

    Höllmer, M.; Willesen, J. L.; Tolver, A.

    2017-01-01

    stroke volume increased, whereas LA reservoir and contractile function decreased with increasing disease severity. A maximal LA volume heart failure in dogs with chronic MMVD with a sensitivity of 96% and a specificity of 100......%. An active LA emptying fraction heart failure in dogs with chronic MMVD with a sensitivity of 77% and a specificity of 89% and a sensitivity of 82% and a specificity of 82%, respectively. CONCLUSION: Dogs with MMVD appear to have larger LA...... of cardiac compensation. Left atrial function in dogs with naturally occurring MMVD remains largely unexplored. The objective of this study was to evaluate LA volume and function in dogs with naturally occurring MMVD. ANIMALS: This prospective study included 205 client-owned dogs of different breeds, 114...

  15. Fractional distillation of oil

    Energy Technology Data Exchange (ETDEWEB)

    Jones, L D

    1931-10-31

    A method of dividing oil into lubricating oil fractions without substantial cracking by introducing the oil in a heated state into a fractionating column from which oil fractions having different boiling points are withdrawn at different levels, while reflux liquid is supplied to the top of the column, and additional heat is introduced into the column by contacting with the oil therein a heated fluid of higher monlecular weight than water and less susceptible to thermal decomposition than is the highest boiling oil fraction resulting from the distillation, or of which any products produced by thermal decomposition will not occur in the highest boiling distillate withdrawn from the column.

  16. Left atrial appendage obliteration in atrial fibrillation patients undergoing bioprosthetic mitral valve replacement.

    Science.gov (United States)

    Min, X P; Zhu, T Y; Han, J; Li, Y; Meng, X

    2016-02-01

    Left atrial appendage (LAA) obliteration is a proven stroke-preventive measure for patients with nonvalvular atrial fibrillation (AF). However, the efficacy of LAA obliteration for patients with AF after bioprosthetic mitral valve replacement (MVR) remains unclear. This study aimed to estimate the efficacy of LAA obliteration in preventing embolism and to investigate the predictors of thromboembolism after bioprosthetic MVR. We retrospectively studied 173 AF subjects with bioprosthetic MVR; among them, 81 subjects underwent LAA obliteration using an endocardial running suture method. The main outcome measure was the occurrence of thrombosis events (TEs). The mean follow-up time was 40 ± 17 months. AF rhythm was observed in 136 patients postoperatively. The incidence rate of TEs was 13.97 % for postoperative AF subjects; a dilated left atrium (LA; > 49.5 mm) was identified as an independent risk factor of TEs (OR = 10.619, 95 % CI = 2.754-40.94, p = 0.001). For postoperative AF patients with or without LAA, the incidence rate of TEs was 15.8 % (9/57) and 12.7 % (10/79; p = 0.603), respectively. The incidence rate of TEs was 2.7 % (1/36) and 4.2 % (2/48) for the subgroup patients with a left atrial diameter of  49.5 mm (p = 0.346). Surgical LAA obliteration in patients with valvular AF undergoing bioprosthetic MVR did not reduce TEs, even when the CHA2DS2-VASc score (a score for estimating the risk of stroke in AF) was ≥ 2 points.

  17. Risk of atrial fibrillation as a function of the electrocardiographic PR interval

    DEFF Research Database (Denmark)

    Nielsen, Jonas Bille; Pietersen, Adrian; Graff, Claus

    2013-01-01

    Prolongation of the PR interval has been associated with an increased risk of incident atrial fibrillation (AF).......Prolongation of the PR interval has been associated with an increased risk of incident atrial fibrillation (AF)....

  18. A randomized study of the effects of exercise training on patients with atrial fibrillation

    DEFF Research Database (Denmark)

    Osbak, Philip Samuel; Mourier, Malene; Kjaer, Andreas

    2011-01-01

    Exercise training is beneficial in ischemic and congestive heart disease. However, the effect on atrial fibrillation (AF) is unknown.......Exercise training is beneficial in ischemic and congestive heart disease. However, the effect on atrial fibrillation (AF) is unknown....

  19. Long-Term Exposure to Traffic-Related Air Pollution and Risk of Incident Atrial Fibrillation

    DEFF Research Database (Denmark)

    Monrad, Maria; Sajadieh, Ahmad; Christensen, Jeppe Schultz

    2017-01-01

    BACKGROUND: Atrial fibrillation is the most common sustained arrhythmia and associated with cardiovascular morbidity and mortality. The few studies conducted on short-term effects of air pollution on episodes of atrial fibrillation indicates a positive association, though not consistently...

  20. Left atrial enlargement increases the risk of major adverse cardiac events independent of coronary vasodilator capacity

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Angela S. [Brigham and Women' s Hospital, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Boston, MA (United States); National Heart Centre Singapore, Singapore (Singapore); Murthy, Venkatesh L.; Sitek, Arkadiusz; Gayed, Peter; Bruyere, John; Di Carli, Marcelo F. [Brigham and Women' s Hospital, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Boston, MA (United States); Wu, Justina [Brigham and Women' s Hospital, Division of Cardiology, Department of Medicine, and the Noninvasive Cardiovascular Imaging Program, Departments of Medicine (Cardiology) and Radiology, Boston, MA (United States); Dorbala, Sharmila [Brigham and Women' s Hospital, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Boston, MA (United States); Brigham and Women' s Hospital, Department of Radiology and the Division of Cardiology, Noninvasive Cardiovascular Imaging Section, Boston, MA (United States)

    2015-09-15

    Longstanding uncontrolled atherogenic risk factors may contribute to left atrial (LA) hypertension, LA enlargement (LAE) and coronary vascular dysfunction. Together they may better identify risk of major adverse cardiac events (MACE). The aim of this study was to test the hypothesis that chronic LA hypertension as assessed by LAE modifies the relationship between coronary vascular function and MACE. In 508 unselected subjects with a normal clinical {sup 82}Rb PET/CT, ejection fraction ≥40 %, no prior coronary artery disease, valve disease or atrial fibrillation, LAE was determined based on LA volumes estimated from the hybrid perfusion and CT transmission scan images and indexed to body surface area. Absolute myocardial blood flow and global coronary flow reserve (CFR) were calculated. Subjects were systematically followed-up for the primary end-point - MACE - a composite of all-cause death, myocardial infarction, hospitalization for heart failure, stroke, coronary artery disease progression or revascularization. During a median follow-up of 862 days, 65 of the subjects experienced a composite event. Compared with subjects with normal LA size, subjects with LAE showed significantly lower CFR (2.25 ± 0.83 vs. 1.95 ± 0.80, p = 0.01). LAE independently and incrementally predicted MACE even after accounting for clinical risk factors, medication use, stress left ventricular ejection fraction, stress left ventricular end-diastolic volume index and CFR (chi-squared statistic increased from 30.9 to 48.3; p = 0.001). Among subjects with normal CFR, those with LAE had significantly worse event-free survival (risk adjusted HR 5.4, 95 % CI 2.3 - 12.8, p < 0.0001). LAE and reduced CFR are related but distinct cardiovascular adaptations to atherogenic risk factors. LAE is a risk marker for MACE independent of clinical factors and left ventricular volumes; individuals with LAE may be at risk of MACE despite normal coronary vascular function. (orig.)

  1. Virtual In-Silico Modeling Guided Catheter Ablation Predicts Effective Linear Ablation Lesion Set for Longstanding Persistent Atrial Fibrillation: Multicenter Prospective Randomized Study.

    Science.gov (United States)

    Shim, Jaemin; Hwang, Minki; Song, Jun-Seop; Lim, Byounghyun; Kim, Tae-Hoon; Joung, Boyoung; Kim, Sung-Hwan; Oh, Yong-Seog; Nam, Gi-Byung; On, Young Keun; Oh, Seil; Kim, Young-Hoon; Pak, Hui-Nam

    2017-01-01

    Objective: Radiofrequency catheter ablation for persistent atrial fibrillation (PeAF) still has a substantial recurrence rate. This study aims to investigate whether an AF ablation lesion set chosen using in-silico ablation (V-ABL) is clinically feasible and more effective than an empirically chosen ablation lesion set (Em-ABL) in patients with PeAF. Methods: We prospectively included 108 patients with antiarrhythmic drug-resistant PeAF (77.8% men, age 60.8 ± 9.9 years), and randomly assigned them to the V-ABL ( n = 53) and Em-ABL ( n = 55) groups. Five different in-silico ablation lesion sets [1 pulmonary vein isolation (PVI), 3 linear ablations, and 1 electrogram-guided ablation] were compared using heart-CT integrated AF modeling. We evaluated the feasibility, safety, and efficacy of V-ABL compared with that of Em-ABL. Results: The pre-procedural computing time for five different ablation strategies was 166 ± 11 min. In the Em-ABL group, the earliest terminating blinded in-silico lesion set matched with the Em-ABL lesion set in 21.8%. V-ABL was not inferior to Em-ABL in terms of procedure time ( p = 0.403), ablation time ( p = 0.510), and major complication rate ( p = 0.900). During 12.6 ± 3.8 months of follow-up, the clinical recurrence rate was 14.0% in the V-ABL group and 18.9% in the Em-ABL group ( p = 0.538). In Em-ABL group, clinical recurrence rate was significantly lower after PVI+posterior box+anterior linear ablation, which showed the most frequent termination during in-silico ablation (log-rank p = 0.027). Conclusions: V-ABL was feasible in clinical practice, not inferior to Em-ABL, and predicts the most effective ablation lesion set in patients who underwent PeAF ablation.

  2. Atrial arrhythmia in ageing spontaneously hypertensive rats: unraveling the substrate in hypertension and ageing.

    Directory of Open Access Journals (Sweden)

    Dennis H Lau

    Full Text Available BACKGROUND: Both ageing and hypertension are known risk factors for atrial fibrillation (AF although the pathophysiological contribution or interaction of the individual factors remains poorly understood. Here we aim to delineate the arrhythmogenic atrial substrate in mature spontaneously hypertensive rats (SHR. METHODS: SHR were studied at 12 and 15 months of age (n = 8 per group together with equal numbers of age-matched normotensive Wistar-Kyoto control rats (WKY. Electrophysiologic study was performed on superfused isolated right and left atrial preparations using a custom built high-density multiple-electrode array to determine effective refractory periods (ERP, atrial conduction and atrial arrhythmia inducibility. Tissue specimens were harvested for structural analysis. RESULTS: COMPARED TO WKY CONTROLS, THE SHR DEMONSTRATED: Higher systolic blood pressure (p<0.0001, bi-atrial enlargement (p<0.05, bi-ventricular hypertrophy (p<0.05, lower atrial ERP (p = 0.008, increased atrial conduction heterogeneity (p = 0.001 and increased atrial interstitial fibrosis (p = 0.006 & CD68-positive macrophages infiltration (p<0.0001. These changes resulted in higher atrial arrhythmia inducibility (p = 0.01 and longer induced AF episodes (p = 0.02 in 15-month old SHR. Ageing contributed to incremental bi-atrial hypertrophy (p<0.01 and atrial conduction heterogeneity (p<0.01 without affecting atrial ERP, fibrosis and arrhythmia inducibility. The limited effect of ageing on the atrial substrate may be secondary to the reduction in CD68-positive macrophages. CONCLUSIONS: Significant atrial electrical and structural remodeling is evident in the ageing spontaneously hypertensive rat atria. Concomitant hypertension appears to play a greater pathophysiological role than ageing despite their compounding effect on the atrial substrate. Inflammation is pathophysiologically linked to the pro-fibrotic changes in the hypertensive atria.

  3. Speckle tracking analysis: a new tool for left atrial function analysis in systemic hypertension: an overview.

    Science.gov (United States)

    Cameli, Matteo; Ciccone, Marco M; Maiello, Maria; Modesti, Pietro A; Muiesan, Maria L; Scicchitano, Pietro; Novo, Salvatore; Palmiero, Pasquale; Saba, Pier S; Pedrinelli, Roberto

    2016-05-01

    Speckle tracking echocardiography (STE) is an imaging technique applied to the analysis of left atrial function. STE provides a non-Doppler, angle-independent and objective quantification of left atrial myocardial deformation. Data regarding feasibility, accuracy and clinical applications of left atrial strain are rapidly gathering. This review describes the fundamental concepts of left atrial STE, illustrates its pathophysiological background and discusses its emerging role in systemic arterial hypertension.

  4. Fractional Poisson process (II)

    International Nuclear Information System (INIS)

    Wang Xiaotian; Wen Zhixiong; Zhang Shiying

    2006-01-01

    In this paper, we propose a stochastic process W H (t)(H-bar (12,1)) which we call fractional Poisson process. The process W H (t) is self-similar in wide sense, displays long range dependence, and has more fatter tail than Gaussian process. In addition, it converges to fractional Brownian motion in distribution

  5. An Appetite for Fractions

    Science.gov (United States)

    Wilkerson, Trena L.; Bryan, Tommy; Curry, Jane

    2012-01-01

    This article describes how using candy bars as models gives sixth-grade students a taste for learning to represent fractions whose denominators are factors of twelve. Using paper models of the candy bars, students explored and compared fractions. They noticed fewer different representations for one-third than for one-half. The authors conclude…

  6. Can Kindergartners Do Fractions?

    Science.gov (United States)

    Cwikla, Julie

    2014-01-01

    Mathematics professor Julie Cwikla decided that she needed to investigate young children's understandings and see what precurricular partitioning notions young minds bring to the fraction table. Cwikla realized that only a handful of studies have examined how preschool-age and early elementary school-age students solve fraction problems (Empson…

  7. Fractional bosonic strings

    Science.gov (United States)

    Diaz, Victor Alfonzo; Giusti, Andrea

    2018-03-01

    The aim of this paper is to present a simple generalization of bosonic string theory in the framework of the theory of fractional variational problems. Specifically, we present a fractional extension of the Polyakov action, for which we compute the general form of the equations of motion and discuss the connection between the new fractional action and a generalization the Nambu-Goto action. Consequently, we analyze the symmetries of the modified Polyakov action and try to fix the gauge, following the classical procedures. Then we solve the equations of motion in a simplified setting. Finally, we present a Hamiltonian description of the classical fractional bosonic string and introduce the fractional light-cone gauge. It is important to remark that, throughout the whole paper, we thoroughly discuss how to recover the known results as an "integer" limit of the presented model.

  8. Effect of atrial systole on canine and porcine coronary blood flow.

    Science.gov (United States)

    Bellamy, R F

    1981-09-01

    A feature of phasic coronary flow patterns recorded in conscious chronically instrumented dogs is the atrial cove--a transient depression of arterial flow that occurs during atrial systole. The association between the hemodynamic effects of atrial systole and the atrial cove was studied in anesthetized dogs and pigs with complete heart block. Many atrial coves are available for study in these preparations because atrial activity continues unabated during the diastolic ventricular arrest that follows cessation of electrical pacing. The effect of atrial systole is to translate the pressure-flow relation found during diastole to a higher intercept pressure without change in slope. The increase in the intercept pressure equals the increase in intramyocardial pressure measured with microtransducers embedded in the left ventricular wall. The decrement in flow during the atrial cove is a direct function of the change in intramyocardial pressure and an inverse function of coronary vascular resistance. Each atrial systole is associated with a forward flow transient in the coronary veins, the peak of which occurs at the same instant as does the nadir of atrial flow. These data suggest that the coronary vessels are acting as collapsible tubes and that the waterfall model of the coronary circulation is applicable. The following sequence is proposed to account for the atrial cove. Atrial systole ejects a bolus of blood into the left ventricle increasing both ventricular cavity and intramyocardial pressures. The increase in intramyocardial pressure raises the back pressure opposing coronary flow, reducing the arterial perfusion pressure gradient and causing flow to fall.

  9. Rapid pacing results in changes in atrial but not in ventricular refractoriness

    NARCIS (Netherlands)

    Schoonderwoerd, BA; Van Gelder, IC; Tieleman, RG; Bel, KJ; Crijns, HJGM

    It is well known that atrial tachycardia causes atrial electrical remodeling, characterized by shortening of atrial effective refractory periods (AERPs) and loss of physiological adaptation of AERP to rate. However, the nature and time course of changes in ventricular effective refractory periods

  10. 77 FR 11121 - Scientific Information Request on Treatment of Atrial Fibrillation

    Science.gov (United States)

    2012-02-24

    ... Information Request on Treatment of Atrial Fibrillation AGENCY: Agency for Healthcare Research and Quality... Review of the Treatment of Atrial Fibrillation, which is currently being conducted by the Evidence-based... the treatment of atrial fibrillation. The EHC Program is dedicated to identifying as many studies as...

  11. 78 FR 11207 - Clinical Study Designs for Surgical Ablation Devices for Treatment of Atrial Fibrillation...

    Science.gov (United States)

    2013-02-15

    ...] Clinical Study Designs for Surgical Ablation Devices for Treatment of Atrial Fibrillation; Guidance for... devices intended for the treatment of atrial fibrillation. DATES: Submit either electronic or written... Study Designs for Surgical Ablation Devices for Treatment of Atrial Fibrillation'' to the Division of...

  12. Meta-analysis identifies six new susceptibility loci for atrial fibrillation

    NARCIS (Netherlands)

    Ellinor, Patrick T; Lunetta, Kathryn L; Albert, Christine M; Glazer, Nicole L; Ritchie, Marylyn D; Smith, Albert V; Arking, Dan E; Müller-Nurasyid, Martina; Krijthe, Bouwe P; Lubitz, Steven A; Bis, Joshua C; Chung, Mina K; Dörr, Marcus; Ozaki, Kouichi; Roberts, Jason D; Smith, J Gustav; Pfeufer, Arne; Sinner, Moritz F; Lohman, Kurt; Ding, Jingzhong; Smith, Nicholas L; Smith, Jonathan D; Rienstra, Michiel; Rice, Kenneth M; Van Wagoner, David R; Magnani, Jared W; Wakili, Reza; Clauss, Sebastian; Rotter, Jerome I; Steinbeck, Gerhard; Launer, Lenore J; Davies, Robert W; Borkovich, Matthew; Harris, Tamara B; Lin, Honghuang; Völker, Uwe; Völzke, Henry; Milan, David J; Hofman, Albert; Boerwinkle, Eric; Chen, Lin Y; Soliman, Elsayed Z; Voight, Benjamin F; Li, Guo; Chakravarti, Aravinda; Kubo, Michiaki; Tedrow, Usha B; Rose, Lynda M; Ridker, Paul M; Conen, David; Tsunoda, Tatsuhiko; Furukawa, Tetsushi; Sotoodehnia, Nona; Xu, Siyan; Kamatani, Naoyuki; Levy, Daniel; Nakamura, Yusuke; Parvez, Babar; Mahida, Saagar; Furie, Karen L; Rosand, Jonathan; Muhammad, Raafia; Psaty, Bruce M; Meitinger, Thomas; Perz, Siegfried; Wichmann, H-Erich; Witteman, Jacqueline C M; Kao, W H Linda; Kathiresan, Sekar; Roden, Dan M; Uitterlinden, Andre G; Rivadeneira, Fernando; McKnight, Barbara; Sjögren, Marketa; Newman, Anne B; Liu, Yongmei; Gollob, Michael H; Melander, Olle; Tanaka, Toshihiro; Stricker, Bruno H Ch; Felix, Stephan B; Alonso, Alvaro; Darbar, Dawood; Barnard, John; Chasman, Daniel I; Heckbert, Susan R; Benjamin, Emelia J; Gudnason, Vilmundur; Kääb, Stefan

    Atrial fibrillation is a highly prevalent arrhythmia and a major risk factor for stroke, heart failure and death. We conducted a genome-wide association study (GWAS) in individuals of European ancestry, including 6,707 with and 52,426 without atrial fibrillation. Six new atrial fibrillation

  13. Time to implement fitness and reduction of fatness in atrial fibrillation therapy

    NARCIS (Netherlands)

    Van Gelder, Isabelle C.; Hobbelt, Anne H.; Brugemann, Johan; Rienstra, Michiel

    This editorial refers to ‘Self-reported physical activity and major adverse events in patients with atrial fibrillation: a report from the EURObservational Research Programme Pilot Survey on Atrial Fibrillation (EORP-AF) General Registry’ by M. Proietti et al. , doi:10.1093/europace/euw150. Atrial

  14. Newer Anticoagulants for Non-Valvular Atrial Fibrillation

    Directory of Open Access Journals (Sweden)

    Joseph M. Harburger

    2012-05-01

    Full Text Available Non-valvular atrial fibrillation is a recognized risk factor for stroke and systemic embolism. It has been clearly established that warfarin reduces the risk of stroke and systemic embolism in persons with atrial fibrillation and additional risk factors for stroke. The use of warfarin, however, requires frequent monitoring, and there is great variability in patient response to warfarin. Warfarin interacts with several medications and foods. In addition, warfarin use portends a significant risk of bleeding. For these reasons, warfarin is frequently not prescribed to persons for whom the drug would provide a clear benefit. Over the past decade, attempts have been made to develop drugs that are at least as safe and effective as warfarin for the treatment of atrial fibrillation that do not require monitoring nor have as many interactions. Initial studies of compounds in this regard ultimately failed due to safety concerns, but over the past two years two novel agents have been approved by the United States Food and Drug Association for anticoagulation in non-valvular atrial fibrillation, another drug is under review, and additional compounds are being studied. This article will review the use of warfarin and these new agents in the treatment of non-valvular atrial fibrillation.

  15. Heart failure and atrial fibrillation: current concepts and controversies.

    Science.gov (United States)

    Van den Berg, M. P.; Tuinenburg, A. E.; Crijns, H. J.; Van Gelder, I. C.; Gosselink, A. T.; Lie, K. I.

    1997-01-01

    Heart failure and atrial fibrillation are very common, particularly in the elderly. Owing to common risk factors both disorders are often present in the same patient. In addition, there is increasing evidence of a complex, reciprocal relation between heart failure and atrial fibrillation. Thus heart failure may cause atrial fibrillation, with electromechanical feedback and neurohumoral activation playing an important mediating role. In addition, atrial fibrillation may promote heart failure; in particular, when there is an uncontrolled ventricular rate, tachycardiomyopathy may develop and thereby heart failure. Eventually, a vicious circle between heart failure and atrial fibrillation may form, in which neurohumoral activation and subtle derangement of rate control are involved. Treatment should aim at unloading of the heart, adequate control of ventricular rate, and correction of neurohumoral activation. Angiotensin converting enzyme inhibitors may help to achieve these goals. Treatment should also include an attempt to restore sinus rhythm through electrical cardioversion, though appropriate timing of cardioversion is difficult. His bundle ablation may be used to achieve adequate rate control in drug refractory cases. PMID:9155607

  16. Ebstein's anomaly as a cause of paroxysmal atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Damjanović Miodrag R.

    2008-01-01

    Full Text Available Background. Ebstein's anomaly is characterized by a displacement of the tricuspid valve toward apex, because of anomalous attachment of the tricuspid leaflets. There are type B of Wolff-Parkinson-White (WPW syndrome and paroxysmal arrhythmias in more than a half of all patients. Case report. We presented a female, 32-year old, with frequent paroxysms of atrial fibrillation. After conversion of rhythm an ECG showed WPW syndrome. Echocardiographic examination discovered normal size of the left cardiac chambers with paradoxical ventricular septal motion. The right ventricle was very small because of its atrialization. The origin of the tricuspid valve was 20 mm closer to apex of the right ventricle than the origin of the mitral valve. Electrophysiological examination showed a posterolateral right accesorial pathway. Atrial fibrillation was induced very easily in electrophysiological laboratory and a successful ablation of accessorial pathway was made. There were no WPW syndrome and paroxysms of atrial fibrillation after that. Conclusion. Ebstein's anomaly is one of the reasons of paroxysmal atrial fibrillation, especially in young persons with WPW syndrome.

  17. Atrial flutter: from ECG to electroanatomical 3D mapping

    Directory of Open Access Journals (Sweden)

    Livio Dei Cas

    2009-08-01

    Full Text Available Atrial flutter is a common arrhythmia that may cause significant symptoms, including palpitations, dyspnea, chest pain and even syncope. Frequently it’s possible to diagnose atrial flutter with a 12-lead surface ECG, looking for distinctive waves in leads II, III, aVF, aVL, V1,V2. Puech and Waldo developed the first classification of atrial flutter in the 1970s. These authors divided the arrhythmia into type I and type II. Therefore, in 2001 the European Society of Cardiology and the North American Society of Pacing and Electrophysiology developed a new classification of atrial flutter, based not only on the ECG, but also on the electrophysiological mechanism. New developments in endocardial mapping, including the electroanatomical 3D mapping system, have greatly expanded our understanding of the mechanism of arrhythmias. More recently, Scheinman et al, provided an updated classification and nomenclature. The terms like common, uncommon, typical, reverse typical or atypical flutter are abandoned because they may generate confusion. The authors worked out a new terminology, which differentiates atrial flutter only on the basis of electrophysiological mechanism. (Heart International 2006; 3-4: 161-70

  18. Managing atrial fibrillation in the elderly: critical appraisal of dronedarone

    Directory of Open Access Journals (Sweden)

    Trigo P

    2011-12-01

    Full Text Available Paula Trigo, Gregory W FischerDepartment of Anesthesiology, Mount Sinai School of Medicine, New York, NY, USAAbstract: Atrial fibrillation is the most commonly seen arrhythmia in the geriatric population and is associated with increased cardiovascular morbidity and mortality. Treatment of the elderly with atrial fibrillation remains challenging for physicians, because this unique subpopulation is characterized by multiple comorbidities requiring chronic use of numerous medications, which can potentially lead to severe drug interactions. Furthermore, age-related changes in the cardiovascular system as well as other physiological changes result in altered drug pharmacokinetics. Dronedarone is a new drug recently approved for the treatment of arrhythmias, such as atrial fibrillation and/or atrial flutter. Dronedarone is a benzofuran amiodarone analog which lacks the iodine moiety and contains a methane sulfonyl group that decreases its lipophilicity. These differences in chemical structure are responsible for making dronedarone less toxic than amiodarone which, in turn, results in fewer side effects. Adverse events for dronedarone include gastrointestinal side effects and rash. No dosage adjustments are required for patients with renal impairment. However, the use of dronedarone is contraindicated in the presence of severe hepatic dysfunction.Keywords: atrial fibrillation, elderly, antiarrhythmic agents, amiodarone, dronedarone

  19. Red Wine, Resveratrol and Atrial Fibrillation

    Science.gov (United States)

    Garavaglia, Juliano; Marcadenti, Aline

    2017-01-01

    Atrial fibrillation (AF) is a common cardiac arrhythmia that is associated with increased risk for cardiovascular disease and overall mortality. Excessive alcohol intake is a well-known risk factor for AF, but this correlation is less clear with light and moderate drinking. Besides, low doses of red wine may acutely prolong repolarization and slow cardiac conduction. Resveratrol, a bioactive polyphenol found in grapes and red wine, has been linked to antiarrhythmic properties and may act as an inhibitor of both intracellular calcium release and pathological signaling cascades in AF, eliminating calcium overload and preserving the cardiomyocyte contractile function. However, there are still no clinical trials at all that prove that resveratrol supplementation leads to improved outcomes. Besides, no observational study supports a beneficial effect of light or moderate alcohol intake and a lower risk of AF. The purpose of this review is to briefly describe possible beneficial effects of red wine and resveratrol in AF, and also present studies conducted in humans regarding chronic red wine consumption, resveratrol, and AF. PMID:29084143

  20. Red Wine, Resveratrol and Atrial Fibrillation

    Directory of Open Access Journals (Sweden)

    Laura Siga Stephan

    2017-10-01

    Full Text Available Atrial fibrillation (AF is a common cardiac arrhythmia that is associated with increased risk for cardiovascular disease and overall mortality. Excessive alcohol intake is a well-known risk factor for AF, but this correlation is less clear with light and moderate drinking. Besides, low doses of red wine may acutely prolong repolarization and slow cardiac conduction. Resveratrol, a bioactive polyphenol found in grapes and red wine, has been linked to antiarrhythmic properties and may act as an inhibitor of both intracellular calcium release and pathological signaling cascades in AF, eliminating calcium overload and preserving the cardiomyocyte contractile function. However, there are still no clinical trials at all that prove that resveratrol supplementation leads to improved outcomes. Besides, no observational study supports a beneficial effect of light or moderate alcohol intake and a lower risk of AF. The purpose of this review is to briefly describe possible beneficial effects of red wine and resveratrol in AF, and also present studies conducted in humans regarding chronic red wine consumption, resveratrol, and AF.

  1. Red Wine, Resveratrol and Atrial Fibrillation.

    Science.gov (United States)

    Stephan, Laura Siga; Almeida, Eduardo Dytz; Markoski, Melissa Medeiros; Garavaglia, Juliano; Marcadenti, Aline

    2017-10-30

    Atrial fibrillation (AF) is a common cardiac arrhythmia that is associated with increased risk for cardiovascular disease and overall mortality. Excessive alcohol intake is a well-known risk factor for AF, but this correlation is less clear with light and moderate drinking. Besides, low doses of red wine may acutely prolong repolarization and slow cardiac conduction. Resveratrol, a bioactive polyphenol found in grapes and red wine, has been linked to antiarrhythmic properties and may act as an inhibitor of both intracellular calcium release and pathological signaling cascades in AF, eliminating calcium overload and preserving the cardiomyocyte contractile function. However, there are still no clinical trials at all that prove that resveratrol supplementation leads to improved outcomes. Besides, no observational study supports a beneficial effect of light or moderate alcohol intake and a lower risk of AF. The purpose of this review is to briefly describe possible beneficial effects of red wine and resveratrol in AF, and also present studies conducted in humans regarding chronic red wine consumption, resveratrol, and AF.

  2. Imaging in percutaneous ablation for atrial fibrillation

    Energy Technology Data Exchange (ETDEWEB)

    Maksimovic, Ruzica [Erasmus Medical Center, Department of Radiology, GD Rotterdam (Netherlands); Institute for Cardiovascular Diseases of the University Medical Center, Belgrade (Czechoslovakia); Dill, Thorsten [Kerckhoff-Heart Center, Department of Cardiology, Bad Nauheim (Germany); Ristic, Arsen D.; Seferovic, Petar M. [Institute for Cardiovascular Diseases of the University Medical Center, Belgrade (Czechoslovakia)

    2006-11-15

    Percutaneous ablation for electrical disconnection of the arrhythmogenic foci using various forms of energy has become a well-established technique for treating atrial fibrillation (AF). Success rate in preventing recurrence of AF episodes is high although associated with a significant incidence of pulmonary vein (PV) stenosis and other rare complications. Clinical workup of AF patients includes imaging before and after ablative treatment using different noninvasive and invasive techniques such as conventional angiography, transoesophageal and intracardiac echocardiography, computed tomography (CT) and magnetic resonance imaging (MRI), which offer different information with variable diagnostic accuracy. Evaluation before percutaneous ablation involves assessment of PVs (PV pattern, branching pattern, orientation and ostial size) to facilitate position and size of catheters and reduce procedure time as well as examining the left atrium (presence of thrombi, dimensions and volumes). Imaging after the percutaneous ablation is important for assessment of overall success of the procedure and revealing potential complications. Therefore, imaging methods enable depiction of PVs and the anatomy of surrounding structures essential for preprocedural management and early detection of PV stenosis and other ablation-related procedures, as well as long-term follow-up of these patients. (orig.)

  3. Imaging in percutaneous ablation for atrial fibrillation

    International Nuclear Information System (INIS)

    Maksimovic, Ruzica; Dill, Thorsten; Ristic, Arsen D.; Seferovic, Petar M.

    2006-01-01

    Percutaneous ablation for electrical disconnection of the arrhythmogenic foci using various forms of energy has become a well-established technique for treating atrial fibrillation (AF). Success rate in preventing recurrence of AF episodes is high although associated with a significant incidence of pulmonary vein (PV) stenosis and other rare complications. Clinical workup of AF patients includes imaging before and after ablative treatment using different noninvasive and invasive techniques such as conventional angiography, transoesophageal and intracardiac echocardiography, computed tomography (CT) and magnetic resonance imaging (MRI), which offer different information with variable diagnostic accuracy. Evaluation before percutaneous ablation involves assessment of PVs (PV pattern, branching pattern, orientation and ostial size) to facilitate position and size of catheters and reduce procedure time as well as examining the left atrium (presence of thrombi, dimensions and volumes). Imaging after the percutaneous ablation is important for assessment of overall success of the procedure and revealing potential complications. Therefore, imaging methods enable depiction of PVs and the anatomy of surrounding structures essential for preprocedural management and early detection of PV stenosis and other ablation-related procedures, as well as long-term follow-up of these patients. (orig.)

  4. Atrial natriuretic factor increases vascular permeability

    International Nuclear Information System (INIS)

    Lockette, W.; Brennaman, B.

    1990-01-01

    An increase in central blood volume in microgravity may result in increased plasma levels of atrial natriuretic factor (ANF). Since elevations in plasma ANF are found in clinical syndromes associated with edema, and since space motion sickness induced by microgravity is associated with an increase in central blood volume and facial edema, we determined whether ANF increases capillary permeability to plasma protein. Conscious, bilaterally nephrectomized male rats were infused with either saline, ANF + saline, or hexamethonium + saline over 2 h following bolus injections of 125I-albumin and 14C-dextran of similar molecular size. Blood pressure was monitored and serial determinations of hematocrits were made. Animals infused with 1.0 micrograms.kg-1.min-1 ANF had significantly higher hematocrits than animals infused with saline vehicle. Infusion of ANF increased the extravasation of 125I-albumin, but not 14C-dextran from the intravascular compartment. ANF also induced a depressor response in rats, but the change in blood pressure did not account for changes in capillary permeability to albumin; similar depressor responses induced by hexamethonium were not accompanied by increased extravasation of albumin from the intravascular compartment. ANF may decrease plasma volume by increasing permeability to albumin, and this effect of ANF may account for some of the signs and symptoms of space motion sickness

  5. Right atrial angiographic evaluation of the posterior isthmus: relevance for ablation of typical atrial flutter.

    Science.gov (United States)

    Heidbüchel, H; Willems, R; van Rensburg, H; Adams, J; Ector, H; Van de Werf, F

    2000-05-09

    Gaining anatomic information about the posterior isthmus is not generally part of flutter ablation procedures. We postulated that right atrial (RA) angiography could rationalize the ablation approach by revealing the conformation of the isthmus. In 100 consecutive patients, biplane RA angiography was performed before ablation to guide catheter contact with the isthmus along its length. Angiography showed a wide variation in the width of the isthmus (17 to 54 mm; 31.3+/-7.9), its angle with the inferior vena cava in the right anterior oblique projection (68 degrees to 114 degrees; 90.3+/-9.0 degrees ), and its lateral position relative to the inferior vena cava in the left anterior oblique projection. A deep sub-Eustachian recess was revealed in 47%, with a mean depth of 4.3+/-2.1 mm (1.5 to 9.4). A Eustachian valve was visualized in 24%. Ablation resulted in bidirectional conduction block (which could be transient) in all, with a median of 2 dragging radiofrequency (RF) applications (2.3+/-2.5 RF applications; 57 degrees C, deep pouches. The number of RF applications decreased statistically throughout the study, indicating a learning curve. No patient had a recurrence after a follow-up of 13+/-11 months. Right atrial angiography reveals a highly variable isthmus anatomy, often showing particular configurations that can make ablation more laborious. Rational adaptation of the ablation approach to these anatomic findings may contribute to successful ablation.

  6. Thickening of the left atrial wall shortly after radiofrequency ablation predicts early recurrence of atrial fibrillation

    International Nuclear Information System (INIS)

    Yokokawa, Miki; Koyama, Keiko; Ino, Toshihiko; Naito, Shigeto; Oshima, Shigeru; Taniguchi, Koichi; Tada, Hiroshi

    2010-01-01

    Inflammatory responses following atrial fibrillation (AF) ablation may aggravate arrhythmogenic activity and cause an early recurrence of AF (ERAF). In 56 patients who underwent circumferential pulmonary vein ablation (CPVA) for paroxysmal AF, cardiovascular magnetic resonance imaging (CMRI) was evaluated in 5 subdivided left atrial (LA) regions before the CPVA and at 1 day and 1 month after. At a mean of 7±10 days after the CPVA, 23 patients (41%) developed 1 or more episodes of AF (ERAF group), while 33 patients (59%) remained free from AF during the first month of follow up (no-ERAF group). LA wall thickness increased 1 day after the CPVA in both groups, as demonstrated by high T2-weighted signal. The LA roof thickness and its increase, however, were greater in the ERAF group than in the no-ERAF group (P<0.05). Regions of delayed enhancement (DE) were also frequently detected in both groups, but the total number of DE regions did not differ between the 2 groups. The thickening of the LA wall associated with a high T2-weighted signal resolved within 1 month. No significant difference between the 2 groups was found in any of the CMRI parameters before or 1 month after CPVA. Thickening of the LA roof shortly after CPVA may predict an ERAF. (author)

  7. Multimodality Cardiac Imaging for the Assessment of Left Atrial Function and the Association With Atrial Arrhythmias

    DEFF Research Database (Denmark)

    Olsen, Flemming Javier; Bertelsen, Litten; de Knegt, Martina Chantal

    2016-01-01

    Several cardiac imaging modalities are able to visualize the left atrium (LA) and, therefore, allow for quantification of both structural and functional properties of this cardiac chamber. In echocardiography, only the maximal LA volume is included in the assessment of diastolic function at the c......Several cardiac imaging modalities are able to visualize the left atrium (LA) and, therefore, allow for quantification of both structural and functional properties of this cardiac chamber. In echocardiography, only the maximal LA volume is included in the assessment of diastolic function...... atrial fibrillation, which will be a point of focus in this review. Pivotal cardiac magnetic resonance imaging studies have revealed high correlation between LA fibrosis and risk of atrial fibrillation recurrence after catheter ablation, and subsequent multimodality imaging studies have uncovered...... an inverse relationship between LA reservoir function and degree of LA fibrosis. This has sparked an increased interest into the application of advanced imaging modalities, including both speckle tracking echocardiography and tissue tracking by cardiac magnetic resonance imaging. Even though increasing...

  8. 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.

  9. Impact of ischemic and valvular heart disease on atrial excitation : A high-resolution epicardial mapping study

    NARCIS (Netherlands)

    E.M.J.P. Mouws (Elisabeth); E. Lanters (Eva); C. Teuwen (Christophe); L. van der Does (Lisette); C. Kik (Charles); S.P. Knops (Simon); A. Yaksh (Ameeta); J.A. Bekkers (Jos); A.J.J.C. Bogers (Ad); N.M.S. de Groot (Natasja)

    2018-01-01

    markdownabstractBackground--The influence of underlying heart disease or presence of atrial fibrillation (AF) on atrial excitation during sinus rhythm (SR) is unknown. We investigated atrial activation patterns and total activation times of the entire atrial epicardial surface during SR in patients

  10. Fractional Order Generalized Information

    Directory of Open Access Journals (Sweden)

    José Tenreiro Machado

    2014-04-01

    Full Text Available This paper formulates a novel expression for entropy inspired in the properties of Fractional Calculus. The characteristics of the generalized fractional entropy are tested both in standard probability distributions and real world data series. The results reveal that tuning the fractional order allow an high sensitivity to the signal evolution, which is useful in describing the dynamics of complex systems. The concepts are also extended to relative distances and tested with several sets of data, confirming the goodness of the generalization.

  11. Fractional finite Fourier transform.

    Science.gov (United States)

    Khare, Kedar; George, Nicholas

    2004-07-01

    We show that a fractional version of the finite Fourier transform may be defined by using prolate spheroidal wave functions of order zero. The transform is linear and additive in its index and asymptotically goes over to Namias's definition of the fractional Fourier transform. As a special case of this definition, it is shown that the finite Fourier transform may be inverted by using information over a finite range of frequencies in Fourier space, the inversion being sensitive to noise. Numerical illustrations for both forward (fractional) and inverse finite transforms are provided.

  12. Social Trust and Fractionalization:

    DEFF Research Database (Denmark)

    Bjørnskov, Christian

    2008-01-01

    This paper takes a closer look at the importance of fractionalization for the creation of social trust. It first argues that the determinants of trust can be divided into two categories: those affecting individuals' trust radii and those affecting social polarization. A series of estimates using...... a much larger country sample than in previous literature confirms that fractionalization in the form of income inequality and political diversity adversely affects social trust while ethnic diversity does not. However, these effects differ systematically across countries, questioning standard...... interpretations of the influence of fractionalization on trust....

  13. Closure of secundum atrial septal defect in adults

    International Nuclear Information System (INIS)

    Elahi, M.M.; Pollock, J.C.S.

    2003-01-01

    Objective: To examine the outcome of ASD closure in adults and the effect of patients age on drug therapy, symptoms and incidence of atrial fibrillation. Results: There were no deaths. Five patients from early in the series were lost to follow-up. Large defect size was associated with patch rather than direct closure but there was extensive crossover. Analysis by age showed that patients over 49 had more postoperative atrial fibrillation (P 0.001), more chest pain (P>0.0001), more postoperative dyspnea (p = 0.021), greater use of diuretics (p = 0.20) and longer hospital stay (10.1 plus minis 2.6 vs. 8.5 plus minis 1.6 days; p = 0.007) than patients under 49. Conclusion: Operation for atrial septal defects in adults can be performed with no mortality and low morbidity. The age at which complications appear more frequent suggests that closer analysis of these patients is required. (author)

  14. Atrial septal defect in a Korean wild raccoon dog.

    Science.gov (United States)

    Yim, Soomi; Choi, Sooyoung; Kim, Jongtaek; Chung, Jin-Young; Park, Inchul

    2017-10-07

    An approximately two-year-old, male 6.1 kg body weight, Korean wild raccoon dog (Nyctereutes procyonoides koreensis) was captured by the wildlife medical rescue center of Kangwon National University. Upon physical examination, the heart rate was 87 beats per min and there were no clinical signs. The hematological, and blood biochemical profiles revealed no remarkable findings; however, thoracic radiographs showed cardiac enlargement, especially in the right atrium. On electrocardiogram, sinus node dysfunction and bradyarrhythmia were revealed. Echocardiography showed a left-to-right shunting atrial septal defect. Based on these findings, this Korean wild raccoon dog was diagnosed with atrial septal defect. This is the rare case report of atrial septal defect in wildlife.

  15. Left atrial thrombus following bilobectomy: a case report

    Directory of Open Access Journals (Sweden)

    Kaya Ugur

    2010-02-01

    Full Text Available Abstract Introduction Left atrial free floating ball thrombus is a relatively rare event, especially without mitral valve disease. Case presentation A 61-year-old Turkish man was admitted to our hospital with a thrombus mass in his left atrium. Five months earlier, he had undergone right bilobectomy and superior bronchoplasty due to squamous cell carcinoma in the lung. The patient had no evidence of cardiac disease except atrial fibrillation and there were no defined embolizations. The thrombus mass was surgically removed. The patient was discharged from hospital on the sixth postoperative day. Conclusion Surgery with cardiopulmonary bypass is a safe method for treatment. The patient should be medicated with warfarin, especially in the presence of atrial fibrillation.

  16. The imaging features of neurologic complications of left atrial myxomas

    International Nuclear Information System (INIS)

    Liao, Wei-Hua; Ramkalawan, Divya; Liu, Jian-Ling; Shi, Wei; Zee, Chi-Shing; Yang, Xiao-Su; Li, Guo-Liang; Li, Jing; Wang, Xiao-Yi

    2015-01-01

    Background: Neurologic complications may be the first symptoms of atrial myxomas. Understanding the imaging features of neurologic complications of atrial myxomas can be helpful for the prompt diagnosis. Objective: To identify neuroimaging features for patients with neurologic complications attributed to atrial myxoma. Methods: We retrospectively reviewed the medical records of 103 patients with pathologically confirmed atrial myxoma at Xiangya Hospital from January 2009 to January 2014. The neuroimaging data for patients with neurologic complications were analyzed. Results: Eight patients with atrial myxomas (7.77%) presented with neurologic manifestations, which constituted the initial symptoms for seven patients (87.5%). Neuroimaging showed five cases of cerebral infarctions and three cases of aneurysms. The main patterns of the infarctions were multiplicity (100.0%) and involvement of the middle cerebral artery territory (80.0%). The aneurysms were fusiform in shape, multiple in number (100.0%) and located in the distal middle cerebral artery (100.0%). More specifically, high-density in the vicinity of the aneurysms was observed on CT for two patients (66.7%), and homogenous enhancement surrounding the aneurysms was detected in the enhanced imaging for two patients (66.7%). Conclusion: Neurologic complications secondary to atrial myxoma consist of cerebral infarctions and aneurysms, which show certain characteristic features in neuroimaging. Echocardiography should be performed in patients with multiple cerebral infarctions, and multiple aneurysms, especially when aneurysms are distal in location. More importantly, greater attention should be paid to the imaging changes surrounding the aneurysms when myxomatous aneurysms are suspected and these are going to be the relevant features in our article

  17. Detection of Rapid Atrial Arrhythmias in SQUID Magnetocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Woong; Kwon, Hyuk Chan; Kim, Ki Dam; Lee, Yong Ho; Kim, Jin Mok; Kim, In Seon; Lim, Hyun Kyoon; Park, Yong Ki [Biomagnetism Research, Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of); Kim, Doo Sang [Seoul Veterans Hospital, Seoul (Korea, Republic of); Lim, Seung Pyung [Chungnam National University Hospital, Daejeon (Korea, Republic of)

    2005-10-15

    We propose a method to measure atrial arrhythmias (AA) such as atrial fibrillation (Afb) and atrial flutter (Afl) with a SQUID magnetocardiograph (MCG) system. To detect AA is one of challenging topics in MCG. As the AA generally have irregular rhythm and atrio-ventricular conduction, the MCG signal cannot be improved by QRS averaging; therefore a SQUID MCG system having a high SNR is required to measure informative atrial excitation with a single scan. In the case of Afb, diminished f waves are much smaller than normal P waves because the sources are usually located on the posterior wall of the heart. In this study, we utilize an MCG system measuring tangential field components, which is known to be more sensitive to a deeper current source. The average noise spectral density of the whole system in a magnetic shielded room was 10 fT/Hz(a) 1 Hz and 5 fT/Hz(a) 100 Hz. We measured the MCG signals of patients with chronic Afb and Afl. Before the AA measurement, the comparison between the measurements in supine and prone positions for P waves has been conducted and the experiment gave a result that the supine position is more suitable to measure the atrial excitation. Therefore, the AA was measured in subject's supine position. Clinical potential of AA measurement in MCG is to find an aspect of a reentry circuit and to localize the abnormal stimulation noninvasively. To give useful information about the abnormal excitation, we have developed a method, separative synthetic aperture magnetometry (sSAM). The basic idea of sSAM is to visualize current source distribution corresponding to the atrial excitation, which are separated from the ventricular excitation and the Gaussian sensor noises. By using sSAM, we localized the source of an Afl successfully.

  18. The imaging features of neurologic complications of left atrial myxomas

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Wei-Hua; Ramkalawan, Divya; Liu, Jian-Ling; Shi, Wei [Department of Radiology, Xiangya Hospital, Central South University, Changsha 410008, Hunan (China); Zee, Chi-Shing [Department of Radiology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033 (United States); Yang, Xiao-Su; Li, Guo-Liang; Li, Jing [Department of Neurology, Xiangya Hospital, Central South University, Changsha 410008, Hunan (China); Wang, Xiao-Yi, E-mail: cjr.wangxiaoyi@vip.163.com [Department of Radiology, Xiangya Hospital, Central South University, Changsha 410008, Hunan (China)

    2015-05-15

    Background: Neurologic complications may be the first symptoms of atrial myxomas. Understanding the imaging features of neurologic complications of atrial myxomas can be helpful for the prompt diagnosis. Objective: To identify neuroimaging features for patients with neurologic complications attributed to atrial myxoma. Methods: We retrospectively reviewed the medical records of 103 patients with pathologically confirmed atrial myxoma at Xiangya Hospital from January 2009 to January 2014. The neuroimaging data for patients with neurologic complications were analyzed. Results: Eight patients with atrial myxomas (7.77%) presented with neurologic manifestations, which constituted the initial symptoms for seven patients (87.5%). Neuroimaging showed five cases of cerebral infarctions and three cases of aneurysms. The main patterns of the infarctions were multiplicity (100.0%) and involvement of the middle cerebral artery territory (80.0%). The aneurysms were fusiform in shape, multiple in number (100.0%) and located in the distal middle cerebral artery (100.0%). More specifically, high-density in the vicinity of the aneurysms was observed on CT for two patients (66.7%), and homogenous enhancement surrounding the aneurysms was detected in the enhanced imaging for two patients (66.7%). Conclusion: Neurologic complications secondary to atrial myxoma consist of cerebral infarctions and aneurysms, which show certain characteristic features in neuroimaging. Echocardiography should be performed in patients with multiple cerebral infarctions, and multiple aneurysms, especially when aneurysms are distal in location. More importantly, greater attention should be paid to the imaging changes surrounding the aneurysms when myxomatous aneurysms are suspected and these are going to be the relevant features in our article.

  19. LEFT ATRIAL FUNCTION: MODERN ASSESSMENT METHODS AND CLINICAL SIGNIFICANCE

    Directory of Open Access Journals (Sweden)

    E. N. Pavlyukova

    2017-01-01

    Full Text Available Assessment of the left atrial (LA function is important aspect of comprehensive cardiovascular system estimation. Many cardiac diseases make an impact to LA work either by direct affect on myocardium or hemodynamic condition changing. It is considered, LA and left ventricle diastolic pressure is interrelated, thus without mitral valve disease LA expanding is a sign of LV filling pressure augmentation. Examination of LA size and function by analysis of atrial reservoir, conduit, and booster pump can predict cardiovascular outcomes in patients with cardiomyopathy, ischemic heart disease and valvular heart disease. The last two decades gave new technologies to accurate and comprehensive LA mechanics estimation, in the first place related to tissue Doppler imaging. Atrial strain and strain rate obtained using two-dimensional speckle-tracking echocardiography have proved to be feasible and reproducible techniques to evaluate LA mechanics.In physiological settings, LA is a highly expandable chamber with relatively low pressures. However in the presence of acute and chronic injury, LA wall stretches. LA stretching is a hallmark of structure changing with myocardial fibrosis and has influence on LA strain and strain rate. LA strain estimation could be useful in the prediction of sinus rhythm restoration and maintenance after cardioversion and catheter ablation. Low values of global longitudinal LA strain indicate irreversible LA remodeling and are related to the atrial fibrillation progression from paroxysmal to permanent forms. The most interesting in these circumstances is the potential contribution of echocardiography to thromboembolic risk stratification in atrial fibrillation and invasive procedures such as atrial ablation. Therefore, at present, the main task is to understand the ways of clinical application of data  obtained during the LA study.

  20. Case of right atrial myxoma with right to left shunt

    Energy Technology Data Exchange (ETDEWEB)

    Nakai, Kenji; Suzuki, Tomoyuki; Ohzeki, Tetsuro (Iwate Medical Coll., Morioka (Japan). School of Medicine)

    1982-12-01

    A case of 49-year-old woman with right atrial myxoma resulting to right to left shunt, diagnosed by cardiac pool isotope image, was reported. She was admitted to our clinic because of progressive shortness of breath. At admission lip cyanosis was noted. Laboratory data included polycythemia, low O/sub 2/ saturation (89%) and high erythrocyte sedimentation rate (65 mm/1 h). Chest x-p showed slight right atrial enlargement, but no pulmonary congestion. The electrocardiogram showed sinus regular rhythm with biphasic p wave in leads II, III, aVf. Although 1st heart sound at the apex was splited, no heart murmur was heard. In usual echocardiographic approach, no abnormal echogram was obtained in the right ventricular region. Lung perfusion scintiscan with Tc-99 m-MAA showed visualization of thyroid gland and kidney, which suggested intracardiac right-to-left shunt. Cardiac pool image with Tc-99m-HSA revealed large photo-deficient area in the right atrium and early visualization of aortic arch. Computor tomography showed large round low density region 8 x 7 cm in size. Based on their findings, this patient was diagnosed as right atrial tumor. At operation a large tumor (diameter 8 x 7 x 7 cm, weight 160g) filled the lower part of the right atrium and was adherent to the anterolateral wall in the right atrium. As a cause of R-L shunt, streched foramen ovale (5 x 10 mm) was found. Tumor histology was typical of atrial myxoma. Post-operative gated cardiac isotope image showed no evidence of residual atrial tumor. Cardiac blood pool isotope imaging was a method for the noninvasive detection and assessment of right atrial myxoma.

  1. Left atrial isolation associated with mitral valve operations.

    Science.gov (United States)

    Graffigna, A; Pagani, F; Minzioni, G; Salerno, J; Viganò, M

    1992-12-01

    Surgical isolation of the left atrium was performed for the treatment of chronic atrial fibrillation secondary to valvular disease in 100 patients who underwent mitral valve operations. From May 1989 to September 1991, 62 patients underwent mitral valve operations (group I); 19, mitral valve operations and DeVega tricuspid annuloplasty (group II); 15, mitral and aortic operations (group III); and 4, mitral and aortic operations and DeVega tricuspid annuloplasty (group IV). Left atrial isolation was performed, prolonging the usual left paraseptal atriotomy toward the left fibrous trigone anteriorly and the posteromedial commissure posteriorly. The incision was conducted a few millimeters apart from the mitral valve annulus, and cryolesions were placed at the edges to ensure complete electrophysiological isolation of the left atrium. Operative mortality accounted for 3 patients (3%). In 79 patients (81.4%) sinus rhythm recovered and persisted until discharge from the hospital. No differences were found between the groups (group I, 80.7%; group II, 68.5%; group III, 86.7%; group IV, 75%; p = not significant). Three late deaths (3.1%) were registered. Long-term results show persistence of sinus rhythm in 71% of group I, 61.2% of group II, 85.8% of group III, and 100% of group IV. The unique risk factor for late recurrence of atrial fibrillation was found to be preoperative atrial fibrillation longer than 6 months. Due to the satisfactory success rate in recovering sinus rhythm, we suggest performing left atrial isolation in patients with chronic atrial fibrillation undergoing valvular operations.

  2. Dynamic cycling in atrial size and flow during obstructive apnoea.

    Science.gov (United States)

    Pressman, Gregg S; Cepeda-Valery, Beatriz; Codolosa, Nicolas; Orban, Marek; Samuel, Solomon P; Somers, Virend K

    2016-01-01

    Obstructive sleep apnoea (OSA) is strongly associated with cardiovascular disease. However, acute cardiovascular effects of repetitive airway obstruction are poorly understood. While past research used a sustained Mueller manoeuver to simulate OSA we employed a series of gasping efforts to better simulate true obstructive apnoeas. This report describes acute changes in cardiac anatomy and flow related to sudden changes in intrathoracic pressure. 26 healthy, normal weight participants performed 5-6 gasping efforts (target intrathoracic pressure -40 mm Hg) while undergoing Doppler echocardiography. 14 participants had sufficient echocardiographic images to allow comparison of atrial areas during the manoeuver with baseline measurements. Mitral and tricuspid E-wave and A-wave velocities postmanoeuver were compared with baseline in all participants. Average atrial areas changed little during the manoeuver, but variance in both atrial areas was significantly greater than baseline. Further, an inverse relationship was noted with left atrial collapse and right atrial enlargement at onset of inspiratory effort. Significant inverse changes were noted in Doppler flow when comparing the first beat postmanoeuver (pMM1) with baseline. Mitral E-wave velocity increased 9.1 cm/s while tricuspid E-wave velocity decreased 7.0 cm/s; by the eighth beat postmanoeuver (pMM8) values were not different from baseline. Mitral and tricuspid A-wave velocities were not different from baseline at pMM1, but both were significantly higher by pMM8. Repetitive obstructive apnoeas produce dynamic, inverse changes in atrial size and Doppler flow across the atrioventricular valves. These observations have important implications for understanding the pathophysiology of OSA.

  3. Atrial and ventricular septal defect with pulmonary and tricuspid valvular anomalies in a dog

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, Y. [Azabu Univ., Sagamihara, Kanagawa (Japan); Wakao, Y.; Watanabe, T.; Minami, T.; Muto, M.; Suzuki, T.; Takahashi, M.; Une, Y.; Nomura, Y.; Ichioka, N.

    1989-12-15

    A 15-month-old male boxer dog weighing 22 kg was referred to Azabu University Animal Hospital for evaluation of the syncopal attack. There was no cardiac murmur, but electrocardiograms revealed an atrial fibrillation. Thoracic radiograph revealed enlargement of the right and left atrial regions. The medical treatment with digitalis and captopril was made for conversion from the atrial fibrillation to the sinus rhythm. By cardiac catheterization, atrial and ventricular septal defect with pulmonary stenosis was demonstrated. The patient died at 20 months from the first medical examination. At autopsy, there were severe enlargement of both atria, atrial defect, and pulmonary and tricuspid valvular anomalies. (author)

  4. Analysis of brain natriuretic peptide in 30 patients with atrial fibrillation

    International Nuclear Information System (INIS)

    Jin Qiang; Lu Jianghui; Li Weipeng; Yuan Yuan; Sun Weili

    2009-01-01

    To investigate the relationship between atrial fibrillation and brain natriuretic peptide (BNP), plasma levels of BNP in 30 patients with atrial fibrillation and 30 health controls were assayed and compared. The results showed that plasma levels of BNP in patients with atrial fibrillation were significantly higher than those of health controls (P<0.05). When the patients with atrial fibrillation were restored sinus rhythm, the concentration of BNP decreased significantly (P<0.05). BNP was a sensitive marker of cardiac dysfunction, and BNP was positively correlated with atrial fibrillation. (authors)

  5. Atrial and ventricular septal defect with pulmonary and tricuspid valvular anomalies in a dog

    International Nuclear Information System (INIS)

    Ishikawa, Y.; Wakao, Y.; Watanabe, T.; Minami, T.; Muto, M.; Suzuki, T.; Takahashi, M.; Une, Y.; Nomura, Y.; Ichioka, N.

    1989-01-01

    A 15-month-old male boxer dog weighing 22 kg was referred to Azabu University Animal Hospital for evaluation of the syncopal attack. There was no cardiac murmur, but electrocardiograms revealed an atrial fibrillation. Thoracic radiograph revealed enlargement of the right and left atrial regions. The medical treatment with digitalis and captopril was made for conversion from the atrial fibrillation to the sinus rhythm. By cardiac catheterization, atrial and ventricular septal defect with pulmonary stenosis was demonstrated. The patient died at 20 months from the first medical examination. At autopsy, there were severe enlargement of both atria, atrial defect, and pulmonary and tricuspid valvular anomalies. (author)

  6. FRACTIONS: CONCEPTUAL AND DIDACTIC ASPECTS

    Directory of Open Access Journals (Sweden)

    Sead Rešić

    2016-09-01

    Full Text Available Fractions represent the manner of writing parts of whole numbers (integers. Rules for operations with fractions differ from rules for operations with integers. Students face difficulties in understanding fractions, especially operations with fractions. These difficulties are well known in didactics of Mathematics throughout the world and there is a lot of research regarding problems in learning about fractions. Methods for facilitating understanding fractions have been discovered, which are essentially related to visualizing operations with fractions.

  7. Fractional Stochastic Field Theory

    Science.gov (United States)

    Honkonen, Juha

    2018-02-01

    Models describing evolution of physical, chemical, biological, social and financial processes are often formulated as differential equations with the understanding that they are large-scale equations for averages of quantities describing intrinsically random processes. Explicit account of randomness may lead to significant changes in the asymptotic behaviour (anomalous scaling) in such models especially in low spatial dimensions, which in many cases may be captured with the use of the renormalization group. Anomalous scaling and memory effects may also be introduced with the use of fractional derivatives and fractional noise. Construction of renormalized stochastic field theory with fractional derivatives and fractional noise in the underlying stochastic differential equations and master equations and the interplay between fluctuation-induced and built-in anomalous scaling behaviour is reviewed and discussed.

  8. Discrete fractional calculus

    CERN Document Server

    Goodrich, Christopher

    2015-01-01

    This text provides the first comprehensive treatment of the discrete fractional calculus. Experienced researchers will find the text useful as a reference for discrete fractional calculus and topics of current interest. Students who are interested in learning about discrete fractional calculus will find this text to provide a useful starting point. Several exercises are offered at the end of each chapter and select answers have been provided at the end of the book. The presentation of the content is designed to give ample flexibility for potential use in a myriad of courses and for independent study. The novel approach taken by the authors includes a simultaneous treatment of the fractional- and integer-order difference calculus (on a variety of time scales, including both the usual forward and backwards difference operators). The reader will acquire a solid foundation in the classical topics of the discrete calculus while being introduced to exciting recent developments, bringing them to the frontiers of the...

  9. Fractional smith chart theory

    KAUST Repository

    Shamim, Atif; Radwan, Ahmed Gomaa; Salama, Khaled N.

    2011-01-01

    matching networks, where the fractional approach proves to be much more versatile and results in a single element matching network for a complex load as compared to the two elements in the conventional approach. © 2010 IEEE.

  10. Exposure-Based Therapy for Symptom Preoccupation in Atrial Fibrillation

    DEFF Research Database (Denmark)

    Särnholm, Josefin; Skúladóttir, Helga; Rück, Christian

    2017-01-01

    Atrial fibrillation (AF) is the most common cardiac arrhythmia. Patients often experience a range of symptoms resulting in a markedly reduced quality of life, and commonly show symptom preoccupation in terms of avoidance and control behaviors. Cognitive behavior therapy (CBT) has been shown...... with symptomatic paroxysmal (intermittent) atrial fibrillation who were assessed pre- and posttreatment and at 6-month follow-up. The CBT lasted 10 weeks and included exposure to physical sensations similar to AF symptoms, exposure to avoided situations or activities, and behavioral activation. We observed large...

  11. Prominent crista terminalis mimicking a right atrial mass: case report

    Directory of Open Access Journals (Sweden)

    Lange Peter

    2010-10-01

    Full Text Available Abstract The crista terminalis is a normal anatomical structure within the right atrium that is not normally visualised in the standard views obtained while performing a transthoracic echocardiogram. In this case report, transthoracic echocardiography suggested the presence of a right atrial mass in a patient with end stage renal disease. However, subsequent transesophageal echocardiography revealed that the right atrial mass was actually a thick muscular bridge in the right atrium consistent with a prominent crista terminalis. An understanding of the anatomy and the echocardiographic appearance of a prominent crista terminalis will minimize the misdiagnosis of this structure avoiding unnecessary expensive additional tests.

  12. Gender Differences in Antithrombotic Treatment for Newly Diagnosed Atrial Fibrillation

    DEFF Research Database (Denmark)

    Mazurek, Michał; Huisman, Menno V; Rothman, Kenneth J

    2018-01-01

    was -0.5% (95% CI, -1.8%, 0.8%). VKAs were prescribed to 32.8% and 31.9% (NOACs 46.8% and 48.3%) of women and men, respectively. No confounder for the association between gender and anticoagulant prescription was identified. Between-gender differences in anticoagulant use (lower use in women compared......AIMS: Data on gender differences in oral anticoagulation for stroke prevention in patients with atrial fibrillation are conflicting, largely limited to regional reports and Vitamin K antagonist (VKA) use. We aimed to analyze gender-specific anticoagulant prescription patterns early following...... atrial fibrillation (difference in prevalence of anticoagulant use...

  13. Intracellular Cadmium Isotope Fractionation

    Science.gov (United States)

    Horner, T. J.; Lee, R. B.; Henderson, G. M.; Rickaby, R. E.

    2011-12-01

    Recent stable isotope studies into the biological utilization of transition metals (e.g. Cu, Fe, Zn, Cd) suggest several stepwise cellular processes can fractionate isotopes in both culture and nature. However, the determination of fractionation factors is often unsatisfactory, as significant variability can exist - even between different organisms with the same cellular functions. Thus, it has not been possible to adequately understand the source and mechanisms of metal isotopic fractionation. In order to address this problem, we investigated the biological fractionation of Cd isotopes within genetically-modified bacteria (E. coli). There is currently only one known biological use or requirement of Cd, a Cd/Zn carbonic anhydrase (CdCA, from the marine diatom T. weissfloggii), which we introduce into the E. coli genome. We have also developed a cleaning procedure that allows for the treating of bacteria so as to study the isotopic composition of different cellular components. We find that whole cells always exhibit a preference for uptake of the lighter isotopes of Cd. Notably, whole cells appear to have a similar Cd isotopic composition regardless of the expression of CdCA within the E. coli. However, isotopic fractionation can occur within the genetically modified E. coli during Cd use, such that Cd bound in CdCA can display a distinct isotopic composition compared to the cell as a whole. Thus, the externally observed fractionation is independent of the internal uses of Cd, with the largest Cd isotope fractionation occurring during cross-membrane transport. A general implication of these experiments is that trace metal isotopic fractionation most likely reflects metal transport into biological cells (either actively or passively), rather than relating to expression of specific physiological function and genetic expression of different metalloenzymes.

  14. 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

  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

    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. 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. This study provides novel insights into understanding atrial electro-mechanics illustrating that AFER impairs atrial contraction due to reduced intracellular Ca2+ transients.

  16. Assessment of blood stasis in left-atrial appendage with electron-beam CT: filling delay in atrial fibrillation

    Energy Technology Data Exchange (ETDEWEB)

    Nakanishi, Tadashi [Dept. of Radiology, National Cardiovascular Center, Suita, Osaka (Japan); Hamada, Seiki [Dept. of Radiology, National Cardiovascular Center, Suita, Osaka (Japan); Takamiya, Makoto [Dept. of Radiology, National Cardiovascular Center, Suita, Osaka (Japan); Kuribayashi, Sachio [Dept. of Radiology, National Cardiovascular Center, Suita, Osaka (Japan); Naito, Hiroaki [Biomedical Research Center, Osaka Univ. School of Medicine, Suita (Japan)

    1994-10-01

    The left-atrial appendage (LAA) is the most frequent site of thrombus formation. The most probable reason is its anatomical structure and blood stasis. We hypothesized that peak time delay should occur in the LAA with stagnant blood flow. We measured peak time delay in LAA against left atrium with the flow-mode study of electron-beam CT for 49 patients (including 23 patients with atrial fibrillation [AF]). Volume-mode scannings were also performed to detect intracardiac thrombi. Patients with atrial fibrillation showed a larger value than those with sinus rhythm. Some AF patients with no filling of contrast media into the LAA and/or thrombus showed a larger value than the others. The value obtained by the flow-mode study might have the potential by the flow-mode study might have the potential to assess blood stasis and to predict the jeopardized state in the LAA. (orig.)

  17. Rapid slowing of the atrial fibrillatory rate after administration of AZD7009 predicts conversion of atrial fibrillation

    DEFF Research Database (Denmark)

    Aunes, Maria; Egstrup, Kenneth; Frison, Lars

    2014-01-01

    to sinus rhythm (SR) and were matched to 35 non-converters. The mean AFR before conversion was 231 fibrillations per minute (fpm), having decreased by 41%; in non-converters, it was 296 fpm at the end of infusion, having decreased by 26%. The rate of decrease was greater in converters at 5 min, -88 vs. -66......BACKGROUND: Effects on the atrial fibrillatory rate (AFR) were studied during infusion with the combined potassium and sodium channel blocker AZD7009. METHODS AND RESULTS: Patients with persistent atrial fibrillation (AF) were randomized to AZD7009 or placebo. Thirty-five patients converted...... fpm (p=0.02), and at 10 min, -133 vs. -111 fpm (p=0.048). The AFR-SD and the exponential decay decreased. A small left atrial area was the only baseline predictor of conversion to SR. CONCLUSIONS: AZD7009 produced a significantly more rapid decrease of the AFR in converters than in non...

  18. Assessment of blood stasis in left-atrial appendage with electron-beam CT: filling delay in atrial fibrillation

    International Nuclear Information System (INIS)

    Nakanishi, Tadashi; Hamada, Seiki; Takamiya, Makoto; Kuribayashi, Sachio; Naito, Hiroaki

    1994-01-01

    The left-atrial appendage (LAA) is the most frequent site of thrombus formation. The most probable reason is its anatomical structure and blood stasis. We hypothesized that peak time delay should occur in the LAA with stagnant blood flow. We measured peak time delay in LAA against left atrium with the flow-mode study of electron-beam CT for 49 patients (including 23 patients with atrial fibrillation [AF]). Volume-mode scannings were also performed to detect intracardiac thrombi. Patients with atrial fibrillation showed a larger value than those with sinus rhythm. Some AF patients with no filling of contrast media into the LAA and/or thrombus showed a larger value than the others. The value obtained by the flow-mode study might have the potential by the flow-mode study might have the potential to assess blood stasis and to predict the jeopardized state in the LAA. (orig.)

  19. Fractional laser skin resurfacing.

    Science.gov (United States)

    Alexiades-Armenakas, Macrene R; Dover, Jeffrey S; Arndt, Kenneth A

    2012-11-01

    Laser skin resurfacing (LSR) has evolved over the past 2 decades from traditional ablative to fractional nonablative and fractional ablative resurfacing. Traditional ablative LSR was highly effective in reducing rhytides, photoaging, and acne scarring but was associated with significant side effects and complications. In contrast, nonablative LSR was very safe but failed to deliver consistent clinical improvement. Fractional LSR has achieved the middle ground; it combined the efficacy of traditional LSR with the safety of nonablative modalities. The first fractional laser was a nonablative erbium-doped yttrium aluminum garnet (Er:YAG) laser that produced microscopic columns of thermal injury in the epidermis and upper dermis. Heralding an entirely new concept of laser energy delivery, it delivered the laser beam in microarrays. It resulted in microscopic columns of treated tissue and intervening areas of untreated skin, which yielded rapid reepithelialization. Fractional delivery was quickly applied to ablative wavelengths such as carbon dioxide, Er:YAG, and yttrium scandium gallium garnet (2,790 nm), providing more significant clinical outcomes. Adjustable laser parameters, including power, pitch, dwell time, and spot density, allowed for precise determination of percent surface area, affected penetration depth, and clinical recovery time and efficacy. Fractional LSR has been a significant advance to the laser field, striking the balance between safety and efficacy.

  20. Left Atrial Size and Function in a Canine Model of Chronic Atrial Fibrillation and Heart Failure

    Science.gov (United States)

    Goldberg, Adam; Kusunose, Kenya; Qamruddin, Salima; Rodriguez, L. Leonardo; Mazgalev, Todor N.; Griffin, Brian P.; Van Wagoner, David R.; Zhang, Youhua; Popović, Zoran B.

    2016-01-01

    Background Our aim was to assess how atrial fibrillation (AF) induction, chronicity, and RR interval irregularity affect left atrial (LA) function and size in the setting of underlying heart failure (HF), and to determine whether AF effects can be mitigated by vagal nerve stimulation (VNS). Methods HF was induced by 4-weeks of rapid ventricular pacing in 24 dogs. Subsequently, AF was induced and maintained by atrial pacing at 600 bpm. Dogs were randomized into control (n = 9) and VNS (n = 15) groups. In the VNS group, atrioventricular node fat pad stimulation (310 μs, 20 Hz, 3–7 mA) was delivered continuously for 6 months. LA volume and LA strain data were calculated from bi-weekly echocardiograms. Results RR intervals decreased with HF in both groups (p = 0.001), and decreased further during AF in control group (p = 0.014), with a non-significant increase in the VNS group during AF. LA size increased with HF (p<0.0001), with no additional increase during AF. LA strain decreased with HF (p = 0.025) and further decreased after induction of AF (p = 0.0001). LA strain decreased less (p = 0.001) in the VNS than in the control group. Beat-by-beat analysis showed a curvilinear increase of LA strain with longer preceding RR interval, (r = 0.45, p <0.0001) with LA strain 1.1% higher (p = 0.02) in the VNS-treated animals, independent of preceding RR interval duration. The curvilinear relationship between ratio of preceding and pre-preceding RR intervals, and subsequent LA strain was weaker, (r = 0.28, p = 0.001). However, VNS-treated animals again had higher LA strain (by 2.2%, p = 0.002) independently of the ratio of preceding and pre-preceding RR intervals. Conclusions In the underlying presence of pacing-induced HF, AF decreased LA strain, with little impact on LA size. LA strain depends on the preceding RR interval duration. PMID:26771573

  1. Regulation of atrial natriuretic peptide (ANP) secretion

    International Nuclear Information System (INIS)

    Ruskoaho, H.; Toth, M.; Lang, R.E.; Unger, Th.; Garten, D.

    1986-01-01

    To investigate the role of calcium, protein kinase C and adenylate cyclase in the ANP secretion, the secretory responses from isolated perfused rat hearts to a calcium channel activator, Bay k8644 (methyl-1,4-dihydro-2,6-dimethyl-3-nitro-4-(2-trifluomethylphenyl)-2-pyridine-5-carboxylate), the calcium ionophore (A23187), the phorbol ester (12-0-tetradecanoylphorbol-13-acetate, TPA), and to forskolin were studied. ANP in perfusate was measured by radioimmunoassay 10 min before and during the infusion (30 min) of various agents at 2 min intervals. A23187 (5.7 x 10 -7 ) induced a sharp increase, whereas TPA (0.15 - 1.6 x 10 -7 ) caused a slowly progressive increase in ANP secretion. 4a-phorbol-12,13-didecanoate, a non-active phorbol ester, had no effect on ANP secretion. Bay k8644 (4 x 10 -7 ) and forskolin (1 x 10 -6 ) alone caused small but sustained increase in ANP secretion. The combination of TPA with Bay k8644, forskolin or A23187 stimulated ANP secretion higher than the calculated additive value for each agent. Dibuturyl-cAMP (1.6 x 10 -4 ) pretreatment also enhanced TPA-induced ANP release. 8-Bromo-cGMP (1.3 x 10 -4 ) and sodium nitroprusside (9 x 10 -5 ) alone had no effect, but both attenuated the TPA-induced ANP secretion. The results suggest that atrial cardiocytes possess at least two different secretory pathways for ANP secretion, which are probably dependent on protein kinase C and cyclic AMP

  2. Plain chest PA evaluation of left atrial thrombosis in mitral valvular disease

    Energy Technology Data Exchange (ETDEWEB)

    Choo, Yeon Myung; Park, Jae Hyung; Han, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1984-09-15

    Conventional posteroanterior chest radiographs of 73 patients with mitral valve disease who had had surgery were analyzed, and particular attention was directed to the absence of the convexity of the left lower mid cardiac border (left atrial segment) and to the relation with duration of illness, atrial fibrillation, pulmonary capillary wedge pressure (PCWP) as well as surgical findings. The results obtained are as follows: 1. The flatness or concavity of this segment, despite other evidence of left atrial enlargement, was observed in eleven (64.7%) of 17 patients who had left atrial thrombosis and in six (10.7%) of 56 patients who did not have thrombosis (false positive diagnosis). Six (35.5%) of the 17 patients who had left atrial thrombosis did not this findings on radiographs (false positive diagnosis). Six (35.3%) of the 17 patients who had left atrial thrombosis did not show this finding on radiographs (false positive diagnosis). Therefore, the accuracy in the diagnosis of thrombosis of left atrium wa 64.7% (eleven of seventeen) for patients who had thrombosis of left atrium. 2. The atrial fibrillation was observed in sixteen (94.1%)of 17 patients who had left atrial thrombosis. So, correlation between the presence of left atrial thrombosis and atrial fibrillation wa evident. But there was no correlation between the duration of illness of the PCWP of patients and the presence of left atrial thrombosis.

  3. Plain chest PA evaluation of left atrial thrombosis in mitral valvular disease

    International Nuclear Information System (INIS)

    Choo, Yeon Myung; Park, Jae Hyung; Han, Man Chung

    1984-01-01

    Conventional posteroanterior chest radiographs of 73 patients with mitral valve disease who had had surgery were analyzed, and particular attention was directed to the absence of the convexity of the left lower mid cardiac border (left atrial segment) and to the relation with duration of illness, atrial fibrillation, pulmonary capillary wedge pressure (PCWP) as well as surgical findings. The results obtained are as follows: 1. The flatness or concavity of this segment, despite other evidence of left atrial enlargement, was observed in eleven (64.7%) of 17 patients who had left atrial thrombosis and in six (10.7%) of 56 patients who did not have thrombosis (false positive diagnosis). Six (35.5%) of the 17 patients who had left atrial thrombosis did not this findings on radiographs (false positive diagnosis). Six (35.3%) of the 17 patients who had left atrial thrombosis did not show this finding on radiographs (false positive diagnosis). Therefore, the accuracy in the diagnosis of thrombosis of left atrium wa 64.7% (eleven of seventeen) for patients who had thrombosis of left atrium. 2. The atrial fibrillation was observed in sixteen (94.1%)of 17 patients who had left atrial thrombosis. So, correlation between the presence of left atrial thrombosis and atrial fibrillation wa evident. But there was no correlation between the duration of illness of the PCWP of patients and the presence of left atrial thrombosis.

  4. Embolic risk in atrial fibrillation that arises from hyperthyroidism: review of the medical literature.

    Science.gov (United States)

    Traube, Elie; Coplan, Neil L

    2011-01-01

    Atrial fibrillation, the most common cardiac complication of hyperthyroidism, occurs in an estimated 10% to 25% of overtly hyperthyroid patients. The prevalence of atrial fibrillation increases with age in the general population and in thyrotoxic patients. Other risk factors for atrial fibrillation in thyrotoxic patients include male sex, ischemic or valvular heart disease, and congestive heart failure. The incidence of arterial embolism or stroke in thyrotoxic atrial fibrillation is less clear. There are many reports of arterial thromboembolism associated with hyperthyroidism, including cases of young adults without coexisting risk factors other than thyrotoxic atrial fibrillation. The use of anticoagulative agents to prevent thromboembolic sequelae of thyrotoxic atrial fibrillation is controversial: National organizations provide conflicting recommendations in their practice guidelines. Herein, we review the medical literature and examine the evidence behind the recommendations in order to determine the best approach to thromboembolic prophylaxis in patients who have atrial fibrillation that is associated with hyperthyroidism.

  5. Fenofibrate inhibits atrial metabolic remodelling in atrial fibrillation through PPAR-α/sirtuin 1/PGC-1α pathway.

    Science.gov (United States)

    Liu, Guang-Zhong; Hou, Ting-Ting; Yuan, Yue; Hang, Peng-Zhou; Zhao, Jing-Jing; Sun, Li; Zhao, Guan-Qi; Zhao, Jing; Dong, Jing-Mei; Wang, Xiao-Bing; Shi, Hang; Liu, Yong-Wu; Zhou, Jing-Hua; Dong, Zeng-Xiang; Liu, Yang; Zhan, Cheng-Chuang; Li, Yue; Li, Wei-Min

    2016-03-01

    Atrial metabolic remodelling is critical for the process of atrial fibrillation (AF). The PPAR-α/sirtuin 1 /PPAR co-activator α (PGC-1α) pathway plays an important role in maintaining energy metabolism. However, the effect of the PPAR-α agonist fenofibrate on AF is unclear. Therefore, the aim of this study was to determine the effect of fenofibrate on atrial metabolic remodelling in AF and explore its possible mechanisms of action. The expression of metabolic proteins was examined in the left atria of AF patients. Thirty-two rabbits were divided into sham, AF (pacing with 600 beats·min(-1) for 1 week), fenofibrate treated (pretreated with fenofibrate before pacing) and fenofibrate alone treated (for 2 weeks) groups. HL-1 cells were subjected to rapid pacing in the presence or absence of fenofibrate, the PPAR-α antagonist GW6471 or sirtuin 1-specific inhibitor EX527. Metabolic factors, circulating biochemical metabolites, atrial electrophysiology, adenine nucleotide levels and accumulation of glycogen and lipid droplets were assessed. The PPAR-α/sirtuin 1/PGC-1α pathway was significantly inhibited in AF patients and in the rabbit/HL-1 cell models, resulting in a reduction of key downstream metabolic factors; this effect was significantly restored by fenofibrate. Fenofibrate prevented the alterations in circulating biochemical metabolites, reduced the level of adenine nucleotides and accumulation of glycogen and lipid droplets, reversed the shortened atrial effective refractory period and increased risk of AF. Fenofibrate inhibited atrial metabolic remodelling in AF by regulating the PPAR-α/sirtuin 1/PGC-1α pathway. The present study may provide a novel therapeutic strategy for AF. © 2016 The British Pharmacological Society.

  6. Circadian variation in dominant atrial fibrillation frequency in persistent atrial fibrillation

    International Nuclear Information System (INIS)

    Sandberg, Frida; Stridh, Martin; Sörnmo, Leif; Bollmann, Andreas; Husser, Daniela

    2010-01-01

    Circadian variation in atrial fibrillation (AF) frequency is explored in this paper by employing recent advances in signal processing. Once the AF frequency has been estimated and tracked by a hidden Markov model approach, the resulting trend is analyzed for the purpose of detecting and characterizing the presence of circadian variation. With cosinor analysis, the results show that the short-term variations in the AF frequency exceed the variation that may be attributed to circadian. Using the autocorrelation method, circadian variation was found in 13 of 18 ambulatory ECG recordings (Holter) acquired from patients with long-standing persistent AF. Using the ensemble correlation method, the highest AF frequency usually occurred during the afternoon, whereas the lowest usually occurred during late night. It is concluded that circadian variation is present in most patients with long-standing persistent AF though the short-term variation in the AF frequency is considerable and should be taken into account

  7. Catheter Ablation of Ectopic Atrial Tachycardia Originating from the Left Atrial Appendage using CARTOMERGE® System

    Directory of Open Access Journals (Sweden)

    Masahiko Goya, MD

    2008-01-01

    Full Text Available A 70-year-old woman was referred because of drug resistant and daily incessant palpitation attack. She had undergone two previous unsuccessful radiofrequency catheter ablations at another hospital. The physical examination, chest X-ray, and echocardiogram were all normal. The 12-lead ECG during tachycardia showed narrow QRS, short PR tachycardia and negative polarity of the P wave in leads I and aVL (Fig. 1A. The ECG monitor showed incessant tachycardia with warming-up phenomenon. Three dimensional electroanatomical map integrated with CT imaging (CARTOMERGE®, Biosense Webster Inc. clearly revealed the radial activation pattern originating from the basalo-postero-inferior aspect of the left atrial appendage. Radiofrequency energy application at this site eliminated tachycardia permanently.

  8. Series expansion in fractional calculus and fractional differential equations

    OpenAIRE

    Li, Ming-Fan; Ren, Ji-Rong; Zhu, Tao

    2009-01-01

    Fractional calculus is the calculus of differentiation and integration of non-integer orders. In a recently paper (Annals of Physics 323 (2008) 2756-2778), the Fundamental Theorem of Fractional Calculus is highlighted. Based on this theorem, in this paper we introduce fractional series expansion method to fractional calculus. We define a kind of fractional Taylor series of an infinitely fractionally-differentiable function. Further, based on our definition we generalize hypergeometric functio...

  9. Left atrial appendage: morphology and function in patients with paroxysmal and persistent atrial fibrillation.

    Science.gov (United States)

    Park, Hwan-Cheol; Shin, Jinho; Ban, Ji-Eun; Choi, Jong-Il; Park, Sang-Weon; Kim, Young-Hoon

    2013-04-01

    The anatomical and functional characteristics of the left atrial appendage (LAA) and its relationships with anatomical remodeling and ischemic stroke in patients with atrial fibrillation (AF) have not been clearly established. The purpose of this study was to determine whether functional and morphological features of the LAA independently predict clinical outcome and stroke in patients with AF who underwent catheter ablation (CA). Two hundred sixty-four patients with AF, including 176 with paroxysmal AF (PAF, 54.0 ± 11.4 years old, M:F = 138:38) and 88 with persistent AF (PeAF, 56.4 ± 9.6 years old, M:F = 74:14) were studied. Of these patients, 31 (11.7 %) had a history of stroke/TIA (transient ischemic attack). The LA and LAA volumes were 124.0 ± 42.4 and 24.9 ± 4.3 ml in PeAF, these values were greater than those in PAF (81.2 ± 24.8 ml and 21.2 ± 5.1 ml, P stroke, stroke patients had larger LA volume (106.9 ± 23.0 vs. 94.0 ± 38.9 ml, P = 0.004) and had lower LAA EF (50.0 ± 11.0 vs. 65.7 ± 13.4 %, P stroke were age (P = 0.002) and LAA EF (P stroke/TIA and recurrence of AF after CA in paroxysmal AF patients. Further large scaled prospective study is required for validation.

  10. Intraoperative Inducibility of Atrial Fibrillation Does Not Predict Early Postoperative Atrial Fibrillation.

    Science.gov (United States)

    Lanters, Eva A H; Teuwen, Christophe P; Yaksh, Ameeta; Kik, Charles; van der Does, Lisette J M E; Mouws, Elisabeth M J P; Knops, Paul; van Groningen, Nicole J; Hokken, Thijmen; Bogers, Ad J J C; de Groot, Natasja M S

    2018-03-10

    Early postoperative atrial fibrillation (EPoAF) is associated with thromboembolic events, prolonged hospitalization, and development of late PoAF (LPoAF). It is, however, unknown if EPoAF can be predicted by intraoperative AF inducibility. The aims of this study are therefore to explore (1) the value of intraoperative inducibility of AF for development of both EPoAF and LPoAF and (2) the predictive value of de novo EPoAF for recurrence of LPoAF. Patients (N=496, 75% male) undergoing cardiothoracic surgery for coronary and/or valvular heart disease were included. AF induction was attempted by atrial pacing, before extracorporeal circulation. All patients were on continuous rhythm monitoring until discharge to detect EPoAF. During a follow-up period of 2 years, LPoAF was detected by ECGs and Holter recordings. Sustained AF was inducible in 56% of patients. There was no difference in patients with or without AF before surgery ( P =0.159), or between different types of surgery ( P =0.687). In patients without a history of AF, incidence of EPoAF and LPoAF was 37% and 2%, respectively. EPoAF recurred in 58% patients with preoperative AF, 53% developed LPoAF. There were no correlations between intraoperative inducibility and EPoAF or LPoAF ( P >0.05). EPoAF was not correlated with LPoAF in patients without a history of AF ( P =0.116), in contrast to patients with AF before surgery ( P <0.001). Intraoperative AF inducibility does not predict development of either EPoAF or LPoAF. In patients with AF before surgery, EPoAF is correlated with LPoAF recurrences. This correlation is absent in patients without AF before surgery. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  11. Atrial ectopy predicts late recurrence of atrial fibrillation after pulmonary vein isolation.

    Science.gov (United States)

    Gang, Uffe J O; Nalliah, Chrishan J; Lim, Toon Wei; Thiagalingam, Aravinda; Kovoor, Pramesh; Ross, David L; Thomas, Stuart P

    2015-06-01

    Late recurrence of atrial fibrillation (AF) after radiofrequency ablation remains significant. Asymptomatic recurrence poses a difficult clinical problem as it is associated with an equally increased risk of stroke and death compared with symptomatic AF events. Meta-analyses reveal that no single preablation patient characteristic efficiently predicts these AF recurrences. This study aimed to evaluate the prognostic value of premature atrial complex (PAC) occurrence with regard to the risk of late AF recurrence after radiofrequency ablation. The study cohort consisted of 124 patients with 7-day Holter recordings at 6 months post radiofrequency ablation for AF. No patients had AF recurrence before this time. Patients were followed-up every 6 months. Holter-detected PACs were defined as any supraventricular complexes occurring >30% earlier than expected. During a median follow-up of 4.2 years (first quartile to third quartile [Q1-Q3]=1.6-4.5), 32 patients (26%) had late recurrences of AF at a median of 462 days (Q1-Q3=319-1026) post radiofrequency ablation. The number of PACs per 24 hours was 248 (Q1-Q3=62-1026) in patients with and 77 (Q1-Q3=24-448) in patients without recurrence of AF (P=0.02). Multivariate analysis of the risk of late AF recurrence found ≥142 PACs per 24 hours to have a hazard ratio 2.84 (confidence interval, 1.26-6.43), P=0.01. This study showed that occurrence of ≥142 PACs per day at 6 months after PVI was independently associated with a significantly increased risk of late AF recurrence. These results could have important clinical implications for the design of post-PVI follow-up. URL: http://www.anzctr.org.au. Unique identifier: ACRTN12606000467538. © 2015 American Heart Association, Inc.

  12. 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.

  13. 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.

  14. Postoperative atrial fibrillation in patients on statins undergoing ...

    African Journals Online (AJOL)

    Introduction: The efficacy of perioperative statin therapy in decreasing postoperative morbidity in patients undergoing valve replacements and repairs is unknown. The aim of our study was to determine whether or not the literature supports the hypothesis that statins decrease postoperative atrial fibrillation (AF), and hence ...

  15. The left atrial catheter: its uses and complications.

    Science.gov (United States)

    Leitman, B S; Naidich, D P; McGuinness, G; McCauley, D I

    1992-11-01

    The authors describe the radiographic appearance of the left atrial catheter, a widely used postsurgical intracardiac device. Recognition of the characteristic appearance of this catheter should be of value in detection of potential complications, including line fracture with resultant retention and/or embolization, infection, prosthetic valve dysfunction, and even cardiac tamponade.

  16. Cancer antigen-125 and risk of atrial fibrillation

    DEFF Research Database (Denmark)

    Cheung, Angel; Gong, Mengqi; Bellanti, Roberto

    2018-01-01

    Background: Cancer antigen-125 (Ca-125) is traditionally recognised as a tumour marker and its role in cardiovascular diseases has been studied only in recent years. Whether Ca-125 is elevated in patients with atrial fibrillation (AF) and its levels predict the risk of AF remains controversial. T...

  17. P-wave duration and the risk of atrial fibrillation

    DEFF Research Database (Denmark)

    Nielsen, Jonas B; Kühl, Jørgen T; Pietersen, Adrian

    2015-01-01

    BACKGROUND: Results on the association between P-wave duration and the risk of atrial fibrillation (AF) are conflicting. OBJECTIVE: The purpose of this study was to obtain a detailed description of the relationship between P-wave duration and the risk of AF. METHODS: Using computerized analysis o...

  18. Paroxysmal Atrial Fibrillation in a Mission-Assigned Astronaut

    Science.gov (United States)

    Bauer, Peter A.; Polk, J. D.

    2010-01-01

    This presentation will explore the clinical and administrative conundrums faced by the flight surgeon upon discovering asymptomatic paroxysmal atrial fibrillation seven months prior to scheduled long duration spaceflight. The presenter will discuss the decision-making process as well as the clinical and operational outcomes.

  19. Pattern of atrial fibrillation and risk of outcomes

    DEFF Research Database (Denmark)

    Banerjee, Amitava; Taillandier, Sophie; Olesen, Jonas Bjerring

    2012-01-01

    BACKGROUND: Risk of stroke and thromboembolism (TE) in patients with non-valvular atrial fibrillation (NVAF) is categorised in stroke risk stratification scores. The role of pattern of NVAF in risk prediction is unclear in contemporary 'real world' cohorts. METHODS AND RESULTS: Patients with NVAF...

  20. Outcomes Associated With Familial Versus Nonfamilial Atrial Fibrillation

    DEFF Research Database (Denmark)

    Gundlund, Anna; Olesen, Jonas Bjerring; Staerk, Laila

    2016-01-01

    BACKGROUND: We examined all-cause mortality and long-term thromboembolic risk (ischemic stroke, transient ischemic attack, systemic thromboembolism) in patients with and without familial atrial fibrillation (AF). METHODS AND RESULTS: Using Danish nationwide registry data, we identified all patients...

  1. Apixaban versus warfarin in patients with atrial fibrillation

    NARCIS (Netherlands)

    Granger, C.B.; Alexander, J.H.; McMurray, J.J.; Lopes, R.D.; Hylek, E.M.; Hanna, M.; Al-Khalidi, H.R.; Ansell, J.; Atar, D.; Avezum, A.; Bahit, M.C.; Diaz, R.; Easton, J.D.; Ezekowitz, J.A.; Flaker, G.; Garcia, D.; Geraldes, M.; Gersh, B.J.; Golitsyn, S.; Goto, S.; Hermosillo, A.G.; Hohnloser, S.H.; Horowitz, J.; Mohan, P.; Jansky, P.; Lewis, B.S.; Lopez-Sendon, J.L.; Pais, P.; Parkhomenko, A.; Verheugt, F.W.A.; Zhu, J.; Wallentin, L.

    2011-01-01

    BACKGROUND: Vitamin K antagonists are highly effective in preventing stroke in patients with atrial fibrillation but have several limitations. Apixaban is a novel oral direct factor Xa inhibitor that has been shown to reduce the risk of stroke in a similar population in comparison with aspirin.

  2. Hospitalisation patterns change over time in patients with atrial fibrillation

    DEFF Research Database (Denmark)

    Fristrup Qvist, Janne; Høgh Sørensen, Pernille; Dixen, Ulrik

    2014-01-01

    INTRODUCTION: Atrial fibrillation (AF) is a cardiac epidemic. In this study, we aimed to describe the causes of hospital-isation in an AF population over time and to study how different AF treatment strategies affected hospitalization. MATERIAL AND METHODS: This was an observational study in which...

  3. Ganglion Plexus Ablation in Advanced Atrial Fibrillation: The AFACT Study

    NARCIS (Netherlands)

    Driessen, Antoine H. G.; Berger, Wouter R.; Krul, Sébastien P. J.; van den Berg, Nicoline W. E.; Neefs, Jolien; Piersma, Femke R.; Chan Pin Yin, Dean R. P. P.; de Jong, Jonas S. S. G.; van Boven, WimJan P.; de Groot, Joris R.

    2016-01-01

    Patients with long duration of atrial fibrillation (AF), enlarged atria, or failed catheter ablation have advanced AF and may require more extensive treatment than pulmonary vein isolation. The aim of this study was to investigate the efficacy and safety of additional ganglion plexus (GP) ablation

  4. Evalutating Inward Rectifier Current Inhibiton for Treatment of Atrial Fibrillation

    NARCIS (Netherlands)

    Ji, Yuan

    2017-01-01

    Atrial Fibrillation (AF) is one of the most common forms of cardiac arrhythmia and affects a large percentage of the human population, especially in the elderly. Currently, more than 6 million Europeans suffer from AF, and due to ageing this number will at least double in the next 50 years.

  5. 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

  6. Maze Procedures for Atrial Fibrillation, From History to Practice.

    Science.gov (United States)

    Kik, Charles; Bogers, Ad J J C

    2011-10-01

    Atrial fibrillation may result in significant symptoms, (systemic) thrombo-embolism, as well as tachycardia-induced cardiomyopathy with cardiac failure, and consequently be associated with significant morbidity and mortality. Nowadays symptomatic atrial fibrillation can be treated with catheter-based ablation, surgical ablation or hybrid approaches. In this setting a fairly large number of surgical approaches and procedures are described and being practised. It should be clear that the Cox-maze procedure resulted from building up evidence and experience in different steps, while some of the present surgical approaches and techniques are being based only on technical feasibility with limited experience, rather than on a process of consequent methodology. Some of the issues still under debate are whether or not the maze procedure can be limited to the left atrium or even to isolation of the pulmonary veins or that bi-atrial procedures are indicated, whether or not cardiopulmonary bypass is to be applied and which route of exposure facilitates an optimal result. In addition, maze procedures are not procedures guide by electrophysiological mapping. At least in theory not in all patients all lesions of the maze procedures are necessary. A history and aspects of current practise in surgical treatment of atrial fibrillation is presented.

  7. Catheter Ablation of Focal Atrial Tachycardia Using Remote Magnetic Navigation

    DEFF Research Database (Denmark)

    Liu, Xiao-Yu; Jacobsen, Peter Karl; Pehrson, Steen

    2018-01-01

    , a total of 56 atrial foci were found. Acute success of the primary ablation was obtained in 52 patients (98%). Mean procedure duration was 109 ± 35 min, ablation duration was 401 sec (interquartile range [IQR], 332 sec), and fluoroscopy time was 5.0 min (IQR, 3.0 min). After a mean follow-up of 31 ± 18...

  8. Atrial Fibrillation in Lusaka – Pathoaetiology, Pathophysiology and ...

    African Journals Online (AJOL)

    RICHY

    functional A-V blocks (see Fuster V et al ). Haemodynamic ... valve disease and left ventricular dysfunction, causes atrial ... to guide management that could reduce or eliminate the occurrence of ..... electromechanical function in AF leads to blood stasis. This, in ..... Initiation After Cardioversion Circulation.;104:802-. 809. 24.

  9. Right atrial hemangioma in the newborn: Utility of fetal imaging

    International Nuclear Information System (INIS)

    Baird, Christopher; Blalock, Shannon; Bengur, Resai; Ikemba, Catherine

    2012-01-01

    We present a rare primary right atrial tumor diagnosed in-utero with fetal echocardiography, and further characterized as a congenital hemangioma with magnetic resonance imaging. Surgical resection was done six days after birth. This case illustrates the complementary roles of evolving advanced imaging techniques for fetuses and infants with congenital heart disease that allows for surgery early in the neonatal period

  10. Management of left atrial myxomas at civil hospital, Karachi

    International Nuclear Information System (INIS)

    Iqbal, M.I.; Khan, A.B.; Aftab, S.; Mahmood, S.A.

    2008-01-01

    To study the outcome of the management of left atrial myxoma. The diagnosis was made according to clinical presentation and echocardiographic examinations. Tumour excised under cardiopulmonary bypass using aortic and bicaval cannulation and moderate hypothermia. Variables noted were surgical approach, pathological findings and complications after surgery. Of the 12 cases, six were male and six female, with a mean age of 33.67+-6.05 years. Fatigue and fever were the most common general symptoms, and dyspnoea the most common cardiologic symptom. The pedunculated atrial tumours were excised by trans-septal approach; tumour size ranged between 1.5x1x0.7 cms to 9x8x6 cms and weight 3-140 gms. Histopathology confirmed the tumours as atrial myxomas. One patient died of cerebrovascular accident on the 3rd postoperative day. So far, there has been no recurrence of the tumours. Surgical treatment with wide excision of left atrial myxomas by trans-septal approach is a suitable approach with negligible chances of recurrence. (author)

  11. Antithrombotic therapy in atrial fibrillation associated with valvular heart disease

    DEFF Research Database (Denmark)

    Lip, Gregory Y H; Collet, Jean Philippe; Caterina, Raffaele de

    2017-01-01

    Atrial fibrillation (AF) is a major worldwide public health problem, and AF in association with valvular heart disease (VHD) is also common. However, management strategies for this group of patients have been less informed by randomized trials, which have largely focused on 'non-valvular AF' pati...

  12. Edoxaban versus warfarin in patients with atrial fibrillation

    NARCIS (Netherlands)

    Giugliano, R.P.; Ruff, C.T.; Braunwald, E.; Murphy, S.A.; Wiviott, S.D.; Halperin, J.L.; Waldo, A.L.; Ezekowitz, M.D.; Weitz, J.I.; Spinar, J.; Ruzyllo, W.; Ruda, M.; Koretsune, Y.; Betcher, J.; Shi, M.; Grip, L.T.; Patel, S.P.; Patel, I.; Hanyok, J.J.; Mercuri, M.; Antman, E.M.; Verheugt, F.W.A.; et al.,

    2013-01-01

    BACKGROUND: Edoxaban is a direct oral factor Xa inhibitor with proven antithrombotic effects. The long-term efficacy and safety of edoxaban as compared with warfarin in patients with atrial fibrillation is not known. METHODS: We conducted a randomized, double-blind, double-dummy trial comparing two

  13. Edoxaban versus Warfarin in Patients with Atrial Fibrillation

    NARCIS (Netherlands)

    Giugliano, Robert P.; Ruff, Christian T.; Braunwald, Eugene; Murphy, Sabina A.; Wiviott, Stephen D.; Halperin, Jonathan L.; Waldo, Albert L.; Ezekowitz, Michael D.; Weitz, Jeffrey I.; Špinar, Jindřich; Ruzyllo, Witold; Ruda, Mikhail; Koretsune, Yukihiro; Betcher, Joshua; Shi, Minggao; Grip, Laura T.; Patel, Shirali P.; Patel, Indravadan; Hanyok, James J.; Mercuri, Michele; Antman, Elliott M.; Braunwald, E.; Antman, E. M.; Giugliano, R. P.; Ruff, C. T.; Morin, S. E.; Hoffman, E. B.; Murphy, S. A.; Deenadayalu, N.; Grip, L.; Mercuri, M.; Lanz, H.; Patel, I.; Curt, V.; Duggal, A.; Hanyok, J.; Davé, J.; Morgan, D.; Choi, Y.; Shi, M.; Jin, J.; Xie, J.; Crerand, W.; Kappelhof, J.; Maxwell, W.; Zhang, X.; Zhang, Z.; de Groot, J. [=Joris R.; de Vos, R.; Hoekstra, J.

    2013-01-01

    BackgroundEdoxaban is a direct oral factor Xa inhibitor with proven antithrombotic effects. The long-term efficacy and safety of edoxaban as compared with warfarin in patients with atrial fibrillation is not known. MethodsWe conducted a randomized, double-blind, double-dummy trial comparing two

  14. Cardiac Arrhythmia: Atrial Flutter in a Newborn. Case Study

    Directory of Open Access Journals (Sweden)

    T.M. Klimenko

    2014-09-01

    Full Text Available The article gives case report of rare in neonatal period cardiac arrhythmia — atrial flutter. The disease is one of the manifestations of life-threatening heart rhythm disorders, has no characteristic clinical picture, is diagnosed only by means of an electrocardiogram.

  15. Atrial fibrillation in patients with sick sinus syndrome

    DEFF Research Database (Denmark)

    Nielsen, Jens Cosedis; Thomsen, Poul Erik B; Højberg, Søren

    2012-01-01

    between minimal-paced programmed AVI = 100 and >100 ms (median value), respectively (P= 0.60).ConclusionsThe present study indicates that a longer baseline PQ-interval is associated with an increased risk of AF in patients with sick sinus syndrome. Atrial fibrillation burden is not associated...

  16. Management and prognosis of atrial fibrillation in diabetic patients

    DEFF Research Database (Denmark)

    Fumagalli, Stefano; Said, Salah A; Laroche, Cecile

    2017-01-01

    Aims: Diabetes mellitus (DM) is one of the most important cardiovascular (CV) risk factors. The aim of this study was to evaluate clinical correlates of DM, including management and outcomes, in the EURObservational Research Programme (EORP) - Atrial Fibrillation (AF) General Pilot (EORP-AF) Regi...

  17. Surgical Ablation of Atrial Fibrillation Using Energy Sources.

    Science.gov (United States)

    Brick, Alexandre Visconti; Braile, Domingo Marcolino

    2015-01-01

    Surgical ablation, concomitant with other operations, is an option for treatment in patients with chronic atrial fibrillation. The aim of this study is to present a literature review on surgical ablation of atrial fibrillation in patients undergoing cardiac surgery, considering energy sources and return to sinus rhythm. A comprehensive survey was performed in the literature on surgical ablation of atrial fibrillation considering energy sources, sample size, study type, outcome (early and late), and return to sinus rhythm. Analyzing studies with immediate results (n=5), the percentage of return to sinus rhythm ranged from 73% to 96%, while those with long-term results (n=20) (from 12 months on) ranged from 62% to 97.7%. In both of them, there was subsequent clinical improvement of patients who underwent ablation, regardless of the energy source used. Surgical ablation of atrial fibrillation is essential for the treatment of this arrhythmia. With current technology, it may be minimally invasive, making it mandatory to perform a procedure in an attempt to revert to sinus rhythm in patients requiring heart surgery.

  18. Atrial fibrillation: To map or not to map?

    NARCIS (Netherlands)

    A. Yaksh (Ameeta); C. Kik (Charles); S.P. Knops (Simon); J.W. Roos-Hesselink (Jolien); A.J.J.C. Bogers (Ad); F. Zijlstra (Felix); M.A. Allessie (Maurits); N.M.S. de Groot (Natasja)

    2014-01-01

    textabstractIsolation of the pulmonary veins may be an effective treatment modality for eliminating atrial fibrillation (AF) episodes but unfortunately not for all patients. When ablative therapy fails, it is assumed that AF has progressed from a trigger-driven to a substrate-mediated arrhythmia.

  19. Plasma Atrial Natriuretic Peptide as a non-invasive biochemical ...

    African Journals Online (AJOL)

    Plasma Atrial Natriuretic Peptide as a non-invasive biochemical marker of dyspnoea in congestive heart failure patients. ... University of Mauritius Research Journal ... score assessed by a 10 graded visual analogue scale in the control group (mean score = 1) and an increased from 1.6 to 6.4 in the heart failure patients.

  20. Transient left atrial dysfunction is a feature of Takotsubo syndrome

    DEFF Research Database (Denmark)

    Stiermaier, Thomas; Graf, Tobias; Möller, Christian

    2017-01-01

    BACKGROUND: Takotsubo syndrome (TTS) is characterized by a transient left and/or right ventricular dysfunction as a consequence of a distinctive pattern of regional wall motion abnormalities. However, a systematic evaluation of the left atrial (LA) function in patients with TTS is lacking. The ai...