Ersbøll, Mads; Andersen, Mads J; Valeur, Nana; Mogensen, Ulrik Madvig; Waziri, Homa; Møller, Jacob Eifer; Hassager, Christian; Søgaard, Peter; Køber, Lars
Peak atrial longitudinal strain (PALS) during the reservoir phase has been proposed as a measure of left atrium function in a range of cardiac conditions, with the potential for added pathophysiological insight and prognostic value. However, no studies have assessed the interrelation of PALS and...... left ventricular longitudinal strain (global longitudinal strain) in large-scale populations in regard to prognosis....
Andrews, Jeffrey Pratt
A practical fiber optic strain sensor has been developed to measure strains in the range of 0.0 to 2.0 percent strain with a resolution ranging between 10 and 100 microstrain depending on sensor design choices. This intensity based sensor measures strain by monitoring strain induced longitudinal misalignment in a novel fiber interconnection. This interconnection is created by aligning fibers within a segment of hollow core fiber. Related splice loss mechanisms are investigated ...
Full Text Available Atrial fibrillation is the most common arrhythmia and is associated with adverse outcomes in hypertrophic cardiomyopathy (HCM. Although left atrial (LA remodeling and dysfunction are known to associate with the development of atrial fibrillation in HCM, the changes of the LA in HCM patients remain unclear. This study aimed to evaluate the changes in LA size and mechanical function in HCM patients compared to control subjects and to determine the characteristics of HCM associated with LA remodeling and dysfunction.Seventy-nine HCM patients (mean age, 54 ± 11 years; 76% were men were compared to 79 age- and sex-matched controls (mean age, 54 ± 11 years; 76% were men and 20 young healthy controls (mean age, 33 ± 5 years; 45% were men. The LA diameter, volume, and mechanical function, including global strain (ε, were evaluated by 2D-speckle tracking echocardiography. The phenotype of HCM, maximal left ventricular (LV wall thickness, LV mass, and presence and extent of late gadolinium enhancement (LGE were evaluated with cardiac magnetic resonance imaging.HCM patients showed increased LA volume index, impaired reservoir function, and decreased LA ε compared to the control subjects. When we divided the HCM group according to a maximal LA volume index (LAVImax of 38.7 ml/m2 or LA ε of 21%, no significant differences in the HCM phenotype and maximal LV wall thickness were observed for patients with LAVImax >38.7 ml/m2 or LA ε ≤21%. Conversely, the LV mass index was significantly higher both in patients with maximal LA volume index >38.7 ml/m2 and with LA ε ≤21% and was independently associated with LAVImax and LA ε. Although the LGE extent was increased in patients with LA ε ≤21%, it was not independently associated with either LAVImax or LA ε.HCM patients showed progressed LA remodeling and dysfunction; the determinant of LA remodeling and dysfunction was LV mass index rather than LV myocardial fibrosis by LGE-magnetic resonance
Pankaj Aggarwal; Shakti Chauhan
We studied the variability in longitudinal growth strains and wood basic density in five-year old trees from five clones (one tree per clone) of Eucalyptus tereticornis.Mean longitudinal growth strain in clones ranged from 466 to 876 μm.There was a significant difference between clones in growth strains and wood basic density.Clone 10 exhibited maximum growth strains and basic density,whereas clone 3 and clone 7 exhibited minimum growth strains and basic density,respectively.Within a tree,the growth strain variation with tree height was high but statistically insignificant while within tree variation in basic density was very small.There was no specific trend in variation in either strain or density within a tree.There was 5％-200％ difference in growth strain on opposite sides of the logs.However two strains showed a strong positive correlation.There was a moderate positive association of wood basic density and mean growth strains in logs.The variation around the periphery emphasize the need to measure strain more than one,preferably on opposite sides at the same height,on a tree to know the mean strain level for the purpose of selection of clones.
Systolic dysfunction, clinical heart failure and elevated levels of neurohormonal peptides are major predictors of adverse outcome after acute myocardial infarction (MI). In the present thesis we evaluated global longitudinal strain (GLS) in patients with acute MI in relation to neurohormonal...
Full Text Available Introduction: Atrial fibrillation (AF is a common dysrhythmia postoperatively after coronary artery bypass grafting (CABG. Myocardial strain and strain-rate imaging is used for the assessment of postoperative atrial fibrillation (POAF as a new echocardiographic method. Methods: PubMed and Scopus were searched thoroughly using the following search terms: (strain and strain rate AND (atrial fibrillation OR AF on March 2015 to find English articles in which the strain and strain-rate echocardiographic imaging had been used for the evaluation of AF in patients undergone CABG. Full text of the relevant papers was fully reviewed for data extraction.Result: Of overall 6 articles found in PubMed, 10 records found in Scopus and 4 articles found through reference list search, only 6 papers fully met the inclusion criteria for further assessment and data extraction. The results of strain and strain-rate assessment showed that in total of 542 patients undergoing CABG, POAF occurred in 106 patients. Studies showed that the reduction of left atrial (LA strain rate is correlated with AF. Consistently, the results of present review showed that LA strain and strain-rate in patients who developed AF postoperatively after CABG are significantly reduced, suggesting that strain and strain-rate could be a predictor of POAF.Conclusion: Based on the obtained results, strain and strain-rate is a suitable and accurate echocardiographic technique in the assessment of left atrial function , and it might be helpful to detect the patients who are at high risk of POAF.
This thesis discusses the Super Learner and Targeted Maximum Likelihood Estimation (TMLE) for longitudinal data structures in nonparametric statistical models. It focuses specifically on time-dependent data structures where the outcome of interest may be described as a counting process. A Super Learner for the conditional intensity of the counting process is proposed based on the minimization of squared error and negative Bernoulli loglikelihood risks. An analytic comparison of the oracle ine...
Full Text Available Abstract Background Regional myocardial function is typically evaluated by visual assessment by experienced users, or by methods requiring substantial post processing time. Visual assessment is subjective and not quantitative. Therefore, the purpose of this study is to develop and validate a simple method to derive quantitative measures of regional wall function from velocity encoded Cardiovascular Magnetic Resonance (CMR, and provide associated normal values for longitudinal strain. Method Both fast field echo (FFE and turbo field echo (TFE velocity encoded CMR images were acquired in three long axis planes in 36 healthy volunteers (13 women, 23 men, age 35±12 years. Strain was also quantified in 10 patients within one week after myocardial infarction. The user manually delineated myocardium in one time frame and strain was calculated as the myocardium was tracked throughout the cardiac cycle using an optimization formulation and mechanical a priori assumptions. A phantom experiment was performed to validate the method with optical tracking of deformation as an independent gold standard. Results There was an excellent agreement between longitudinal strain measured by optical tracking and longitudinal strain measured with TFE velocity encoding. Difference between the two methods was 0.0025 ± 0.085 (ns. Mean global longitudinal strain in the 36 healthy volunteers was −0.18 ± 0.10 (TFE imaging. Intra-observer variability for all segments was 0.00 ± 0.06. Inter-observer variability was −0.02 ± 0.07 (TFE imaging. The intra-observer variability for radial strain was high limiting the applicability of radial strain. Mean longitudinal strain in patients was significantly lower (−0.15± 0.12 compared to healthy volunteers (p Conclusion In conclusion, we have developed and validated a robust and clinically applicable technique that can quantify longitudinal strain and regional myocardial wall function and present the associated normal values
Carstensen, Helle Gervig; Larsen, Linnea Hornbech; Hassager, Christian;
AIMS: To evaluate the prognostic value of global longitudinal strain (GLS) and basal longitudinal strain (BLS) with the knowledge of coexisting coronary pathology evaluated by multi-detector computed tomography (MDCT) coronary angiography. BACKGROUND: GLS and BLS are both sensitive markers of...... contrast to GLS, reduced BLS is a significant predictor of future AVR in asymptomatic patients with aortic stenosis, independently of clinical characteristics, conventional echocardiographic measures, and coronary pathology....
Holter monitor tracing showing blocked atrial ectopics and atrial ectopic precipitating atrial fibrillation is being demonstrated. Initially it was coarse atrial fibrillation, which rapidly degenerated into fine atrial fibrillation.
Choy-Lye Chei; Prassanna Raman; Chi Keong Ching; Zhao-Xue Yin; Xiao-Ming Shi; Yi Zeng; David B Matchar
Background:Prevalence of atrial fibrillation (AF) is increasing as the world ages.AF is associated with higher risk of mortality and disease,including stroke,hypertension,heart failure,and dementia.Prevalence of AF differs with each population studied,and research on non-Western populations and the oldest old is scarce.Methods:We used data from the 2012 wave of the Chinese Longitudinal Healthy Longevity Survey,a community-based study in eight longevity areas in China,to estimate AF prevalence in an elderly Chinese population (n =1418,mean age =85.6 years) and to identify risk factors.We determined the presence of AF in our participants using single-lead electrocardiograms.The weighted prevalence of AF was estimated in subjects stratified according to age groups (65-74,75-84,85-94,95 years and above) and gender.We used logistic regressions to determine the potential risk factors of AF.Results:The overall prevalence of AF was 3.5％; 2.4％ of men and 4.5％ of women had AF (P ＜ 0.05).AF was associated with weight extremes of being underweight or overweight/obese.Finally,advanced age (85-94 years),history of stroke or heart disease,low high-density lipoprotein levels,low triglyceride levels,and lack of regular physical activity were associated with AF.Conclusions:In urban elderly,AF prevalence increased with age (P ＜ 0.05),and in rural elderly,women had higher AF prevalence (P ＜ 0.05).Further exploration of population-specific risk factors is needed to address the AF epidemic.
Utilizing longitudinal panel data from Youth In Transition Project, the Person-Environment fit (P-E Fit) theory and its specific application to the area of delinquency and aggression was investigated longitudinally. Analysis of Covariance Structure Technique (LISREL) was used to address the issues of multi-dimensionality, stability, measurement of total P-E fit and to test the proposed delinquency model. The relationships between P-E fit, psychological strain, and delinquency were tested both...
Carstensen, Helle Gervig; Larsen, Linnea Hornbech; Hassager, Christian;
. Thus the purpose of this study was to evaluate the association between subclinical ischemic heart disease and global and regional longitudinal strain in asymptomatic patients with significant aortic stenosis. Prevalent patients with a diagnosis of aortic stenosis at six hospitals in the Greater...... independent of aortic valve area, stroke volume index, pro-BNP, valvulo-arterial impedance, body mass index and heart rate. In linear regression models with both aortic valve area and significant coronary stenosis, apical (p < 0.001) and mid (p < 0.01) longitudinal strain were associated to significant...
Liu, Dan; Hu, Kai; Nordbeck, Peter; Ertl, Georg; Störk, Stefan; Weidemann, Frank
Despite substantial advances in the imaging techniques and pathophysiological understanding over the last decades, identification of the underlying causes of left ventricular hypertrophy by means of echocardiographic examination remains a challenge in current clinical practice. The longitudinal strain bull's eye plot derived from 2D speckle tracking imaging offers an intuitive visual overview of the global and regional left ventricular myocardial function in a single diagram. The bull's eye mapping is clinically feasible and the plot patterns could provide clues to the etiology of cardiomyopathies. The present review summarizes the longitudinal strain, bull's eye plot features in patients with various cardiomyopathies and concentric left ventricular hypertrophy and the bull's eye plot features might serve as one of the cardiac workup steps on evaluating patients with left ventricular hypertrophy. PMID:27165726
Antônio Américo Cardoso Junior; Paulo Fernando Trugilho; José Tarcísio Lima; Sebastião Carlos da Silva Rosado; Lourival Marin Mendes
The utilization of Eucalyptus as supplier of raw-material for sawmills has been progressively increased. Trees of bothbest quality and dimensions represent an important market requirement. Therefore, the effects of forestry treats on the woodcharacteristics must be evaluated. This work veriied the influence of the spacing and of the age in the longitudinal residual strain(LRS), associated to the growth stresses, in clones of Eucalyptus. For determining LRS it was utilised an extensometer CIRA...
Frank, Christine; Davis, Christopher G; Elgar, Frank J
Although the health consequences of financial strain are well documented, less is understood about the health-protective role of social capital. Social capital refers to a sense of community embeddedness, which is in part reflected by group membership, civic participation, and perceptions of trust, cohesion, and engagement. We investigated whether perceptions of social capital moderate the relation between financial strain and health, both mental and physical. This longitudinal study surveyed adults in two communities in rural Ontario where significant job losses recently occurred. Data were collected on financial strain, social capital, perceived stress, symptoms of anxiety and depression, and physical health on three occasions over 18 months (N's = 355, 317, and 300). As expected, financial strain positively related to perceived stress, poor physical health and symptoms of anxiety and depression, whereas social capital related to less stress, better physical health, and fewer symptoms of anxiety and depression. Effects of financial strain on perceived stress and depressive symptoms were moderated by social capital such that financial strain related more closely to perceived stress and depressive symptoms when social capital was lower. The findings underscore the health-protective role of community associations among adults during difficult economic times. PMID:24251877
Wang, Ping; Xie, Kaize; Shao, Liyang; Yan, Lianshan; Xu, Jingmang; Chen, Rong
In this work, a new method has been proposed to accurately determine longitudinal force measurement in continuous welded rail (CWR) with bi-directional fiber Bragg grating (B-FBGs) strain sensors (vertically and longitudinally installed according to the axis of rail). The response of B-FBGs has been theoretically analyzed by binding on CWR under different restrained conditions, where the coefficient of strain sensitivity of FBG is calibrated by its temperature sensitivity. Then the proposed sensor structure has been installed at two elaborately selected points on the subgrade on a Chinese high-speed railway in field. The experiment lasts for about 23 h. During the experiment, the rail temperature varied by about 7.8 °C and the differentials of relative value of wavelength change of B-FBGs of two points were 1.7850 × 10-5 and 1.4969 × 10-5. The maximum difference between the experimental and theoretical results is 13.8 kN. The experimental results agree with the theoretical analysis very well. To guarantee the measurement accuracy of over 95%, the ratio of strain sensitivity coefficients of two FBG sensors of B-FBGs structure at one test point shall be within 0.78 ˜ 1.22.
Kawakubo, Masateru, E-mail: firstname.lastname@example.org [Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan); Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan); Nagao, Michinobu, E-mail: email@example.com [Department of Molecular Imaging and Diagnosis, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan); Kumazawa, Seiji, E-mail: firstname.lastname@example.org [Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan); Chishaki, Akiko S., E-mail: email@example.com [Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan); Mukai, Yasushi, E-mail: firstname.lastname@example.org [Department of Cardiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan); Nakamura, Yasuhiko, E-mail: email@example.com [Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan); Honda, Hiroshi, E-mail: firstname.lastname@example.org [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan); Morishita, Junji, E-mail: email@example.com [Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan)
Purpose: We investigated the clinical performance of evaluation of cardiac mechanical dyssynchrony with longitudinal strain analysis using four-chamber (4CH) cine magnetic resonance imaging (MRI). Materials and methods: We retrospectively enrolled 73 chronic heart failure patients (41 men, 32 women; mean age, 57 years, NYHA 2, 3, and 4) who underwent a cardiac MRI in the present study. The left ventricular dyssynchrony (LVD) and interventricular dyssynchrony (IVD) indices were calculated by longitudinal strain analysis using 4CH cine MRI. The LVD and IVD indices were compared by the Wilcoxon rank-sum test between the patients with indication for cardiac resynchronization therapy (CRT) (n = 13) and without indication for CRT (n = 60), with LGE (n = 40) and without LGE (n = 27), the CRT responders (n = 8) and non-responders (n = 6), respectively. Results: LVD in the patients with indication for CRT were significantly longer than those without indication for CRT (LVD: 92 ± 65 vs. 28 ± 40 ms, P < .01). LVD and IVD were significantly longer in the patients with LGE than those without LGE (LVD: 54 ± 58 vs. 21 ± 30 ms, P < .01 and IVD: 51 ± 39 vs. 23 ± 34 ms, P < .01). LVD and IVD in the CRT responders were significantly longer than the CRT non-responders (LVD: 126 ± 55 vs. 62 ± 55 ms, P < .01 and IVD: 96 ± 39 vs. 52 ± 40 ms, P < .05). Conclusion: Longitudinal strain analysis with 4CH cine MRI could be useful for clinical examination in the evaluation of cardiac mechanical dyssynchrony.
Purpose: We investigated the clinical performance of evaluation of cardiac mechanical dyssynchrony with longitudinal strain analysis using four-chamber (4CH) cine magnetic resonance imaging (MRI). Materials and methods: We retrospectively enrolled 73 chronic heart failure patients (41 men, 32 women; mean age, 57 years, NYHA 2, 3, and 4) who underwent a cardiac MRI in the present study. The left ventricular dyssynchrony (LVD) and interventricular dyssynchrony (IVD) indices were calculated by longitudinal strain analysis using 4CH cine MRI. The LVD and IVD indices were compared by the Wilcoxon rank-sum test between the patients with indication for cardiac resynchronization therapy (CRT) (n = 13) and without indication for CRT (n = 60), with LGE (n = 40) and without LGE (n = 27), the CRT responders (n = 8) and non-responders (n = 6), respectively. Results: LVD in the patients with indication for CRT were significantly longer than those without indication for CRT (LVD: 92 ± 65 vs. 28 ± 40 ms, P < .01). LVD and IVD were significantly longer in the patients with LGE than those without LGE (LVD: 54 ± 58 vs. 21 ± 30 ms, P < .01 and IVD: 51 ± 39 vs. 23 ± 34 ms, P < .01). LVD and IVD in the CRT responders were significantly longer than the CRT non-responders (LVD: 126 ± 55 vs. 62 ± 55 ms, P < .01 and IVD: 96 ± 39 vs. 52 ± 40 ms, P < .05). Conclusion: Longitudinal strain analysis with 4CH cine MRI could be useful for clinical examination in the evaluation of cardiac mechanical dyssynchrony
Antônio Américo Cardoso Junior
Full Text Available The utilization of Eucalyptus as supplier of raw-material for sawmills has been progressively increased. Trees of bothbest quality and dimensions represent an important market requirement. Therefore, the effects of forestry treats on the woodcharacteristics must be evaluated. This work veriied the influence of the spacing and of the age in the longitudinal residual strain(LRS, associated to the growth stresses, in clones of Eucalyptus. For determining LRS it was utilised an extensometer CIRADForêt. The experiment indicated a linear reduction in LRS with the enlargement of the spacing and a tendency of quadratic variationfor the age factor.
Kobayashi, Yukari; Ariyama, Miyuki; Kobayashi, Yuhei; Giraldeau, Genevieve; Fleischman, Dominik; Kozelj, Mirta; Vrtovec, Bojan; Ashley, Euan; Kuznetsova, Tatiana; Schnittger, Ingela; Liang, David; Haddad, Francois
Systolic global longitudinal strain (GLS) is emerging as a useful metric of ventricular function in heart failure and usually assessed using post-processing software. The purpose of this study was to investigate whether longitudinal strain (LS) derived using manual-tracings of ventricular lengths (manual-LS) can be reliable and time efficient when compared to LS obtained by post-processing software (software-LS). Apical 4-chamber view images were retrospectively examined in 50 healthy controls, 100 patients with dilated cardiomyopathy (DCM), and 100 with hypertrophic cardiomyopathy (HCM). We measured endocardial and mid-wall manual-LS and software-LS, using peak of average regional curve [software-LS(a)] and global ventricular lengths [software-LS(l)] according to definition of Lagragian strain. We compared manual-LS and software-LS by using Bland-Altman plot and coefficient of variation (COV). In addition, test-retest was also performed for further assessment of variability in measurements. While manual-LS was obtained in all subjects, software-LS could be obtained in 238 subjects (95 %). The time spent for obtaining manual-LS was significantly shorter than for the software-LS (94 ± 39 s vs. 141 ± 79 s, P controls]. The COV for manual and software derived LS were below 6 %. Test-retest showed good variability for both methods (COVs were 5.8 and 4.7 for endocardial and mid-wall manual-LS, and 4.6 and 4.9 for endocardial and mid-wall software-LS(a), respectively. Manual-LS appears to be as reproducible as software-LS; this may be of value especially when global strain is the metric of interest. PMID:26578468
Ploeckl Marina; Kuhn Peter; Koerber Hannes
In the presented work, an experimental investigation has been performed to characterize the strain rate dependency of unidirectional carbon fiber reinforced polyamide-6 composite for longitudinal compression loading. An end-loaded compression specimen geometry, suitable for contactless optical strain measurement via digital image correlation and dynamic loading in a split-Hopkinson pressure bar, was developed. For the dynamic experiments at a constant strain rate of 100 s−1 a modified version...
We investigated the population structure of 208 Candida dubliniensis isolates obtained from 29 patients (25 human immunodeficiency virus [HIV] positive and 4 HIV negative) as part of a longitudinal study. The isolates were identified as C. dubliniensis by arbitrarily primed PCR (AP-PCR) and then genotyped using the Cd25 probe specific for C. dubliniensis. The majority of the isolates (55 of 58) were unique to individual patients, and more than one genotype was recovered from 15 of 29 patients. A total of 21 HIV-positive patients were sampled on more than one occasion (2 to 36 times). Sequential isolates recovered from these patients were all closely related, as demonstrated by hybridization with Cd25 and genotyping by PCR. Six patients were colonized by the same genotype of C. dubliniensis on repeated sampling, while strains exhibiting altered genotypes were recovered from 15 of 21 patients. The majority of these isolates demonstrated minor genetic alterations, i.e., microevolution, while one patient acquired an unrelated strain. The C. dubliniensis strains could not be separated into genetically distinct groups based on patient viral load, CD4 cell count, or oropharyngeal candidosis. However, C. dubliniensis isolates obtained from HIV-positive patients were more closely related than those recovered from HIV-negative patients. Approximately 8% (16 of 194) of isolates exhibited itraconazole resistance. Cross-resistance to fluconazole was only observed in one of these patients. Two patients harboring itraconazole-resistant isolates had not received any previous azole therapy. In conclusion, longitudinal genotyping of C. dubliniensis isolates from HIV-infected patients reveals that isolates from the same patient are generally closely related and may undergo microevolution. In addition, isolates may acquire itraconazole resistance, even in the absence of prior azole therapy.
Full Text Available In the presented work, an experimental investigation has been performed to characterize the strain rate dependency of unidirectional carbon fiber reinforced polyamide-6 composite for longitudinal compression loading. An end-loaded compression specimen geometry, suitable for contactless optical strain measurement via digital image correlation and dynamic loading in a split-Hopkinson pressure bar, was developed. For the dynamic experiments at a constant strain rate of 100 s−1 a modified version of the Dynamic Compression Fixture, developed by Koerber and Camanho [Koerber and Camanho, Composites Part A, 42, 462–470, 2011] was used. The results were compared with quasi-static test results at a strain rate of 3 · 10−4 s−1 using the same specimen geometry. It was found that the longitudinal compressive strength increased by 61% compared to the strength value obtained from the quasi-static tests.
Ploeckl, Marina; Kuhn, Peter; Koerber, Hannes
In the presented work, an experimental investigation has been performed to characterize the strain rate dependency of unidirectional carbon fiber reinforced polyamide-6 composite for longitudinal compression loading. An end-loaded compression specimen geometry, suitable for contactless optical strain measurement via digital image correlation and dynamic loading in a split-Hopkinson pressure bar, was developed. For the dynamic experiments at a constant strain rate of 100 s-1 a modified version of the Dynamic Compression Fixture, developed by Koerber and Camanho [Koerber and Camanho, Composites Part A, 42, 462-470, 2011] was used. The results were compared with quasi-static test results at a strain rate of 3 · 10-4 s-1 using the same specimen geometry. It was found that the longitudinal compressive strength increased by 61% compared to the strength value obtained from the quasi-static tests.
Magnani, Jared W.; Johnson, Victor M; Sullivan, Lisa M.; Gorodeski, Eiran Z.; Schnabel, Renate B.; Lubitz, Steven A.; Levy, Daniel; Ellinor, Patrick T.; Benjamin, Emelia J.
Long-term risk prediction is a priority for the prevention of atrial fibrillation (AF). P wave indices are electrocardiographic measurements describing atrial conduction. The role of P wave indices in the prospective determination of AF and mortality risk has had limited assessment. We quantified by digital caliper the P wave indices of maximum duration and dispersion in 1,550 Framingham Heart Study participants ≥60 years old (58% women) from single-channel electrocardiograms recorded from 19...
Slavikova, Jana; Mistrova, Eliska; Klenerova, Vera; Kruzliak, Peter; Caprnda, Martin; Hynie, Sixtus; Sida, Pavel; Dvorakova, Magdalena Chottova
Atrial natriuretic peptide (ANP) is produced and released by mammalian cardiomyocytes and induces natriuresis, diuresis, and lowering of blood pressure. The present study examined localization of ANP and a possible role of the hypothalamic-pituitary-adrenal axis (HPA) activity on the expression of proANP gene in the heart. The Sprague Dawley (SD) and Lewis (LE) rat strains were used. The animals were exposed to the two types of stress: immobilization and immobilization combined with water immersion for 1 hour. Localization of ANP was detected by immunohistochemistry and expression of the proANP mRNA by real-time qPCR in all heart compartments of control and stressed animals after 1 and 3 hours after stress termination (IS1, IS3, ICS1, and ICS3). Relatively high density of ANP-immunoreactivity was observed in both atria of both rat strains. In control rats of both strains, the expression of the proANP mRNA was higher in the atria than in ventricles. In SD rats with the intact HPA axis, an upregulation of ANP gene expression was observed in the right atrium after IS1, in both atria and the left ventricle after IS3 and in the left atrium and the left ventricle after ICS3. In LE rats with a blunted reactivity of the HPA axis, no increase or even a downregulation of the gene expression was observed. Thus, acute stress-induced increase in the expression of the proANP gene is related to the activity of the HPA axis. It may have relevance to ANP-induced protection of the heart. PMID:27508036
Prediction of all-cause mortality and heart failure admissions from global left ventricular longitudinal strain in patients with acute myocardial infarction and preserved left ventricular ejection fraction
Ersbøll, Mads; Valeur, Nana; Mogensen, Ulrik Madvig;
This study sought to test the hypothesis that semiautomated calculation of left ventricular global longitudinal strain (GLS) can identify high-risk subjects among patients with myocardial infarctions (MIs) with left ventricular ejection fractions (LVEFs) >40%.......This study sought to test the hypothesis that semiautomated calculation of left ventricular global longitudinal strain (GLS) can identify high-risk subjects among patients with myocardial infarctions (MIs) with left ventricular ejection fractions (LVEFs) >40%....
赵映; 李治安; 孙琳; 栾姝蓉; 刘文旭; 何怡华; 杨娅
目的:应用二维斑点追踪应变率技术,评价正常人节段性左心房功能.方法:在心尖四腔及两腔心切面,应用二维斑点追踪技术,评价44例正常人各节段左心房长轴方向的应变率(SR).比较心室收缩期(SR-S)、舒张早期(SR-E)和舒张晚期(SR-A)心房间隔、侧壁、下壁、前壁以及基底段、中间段和房顶部SR之间的差异性.结果:SR-S、SR-A的基底段和中间段均为下壁最高,间隔最低(均P＜0 05);SR-E 4个房壁同一节段之间差异均有统计学意义.SR-S、SR-E下壁和侧壁基底段均高于房顶部(均P ＜0.05);SR-A则仅为下壁基底段高于房顶部(P＜0 05).结论:正常人心动周期中表现为左心房下壁和侧壁变形能力最高,且基底段高于房顶部.二维斑点追踪技术,可为临床上评价不同病理状态下左心房功能节段性改变的位置和程度提供重要信息.%Objective: The aim of the study was to assess the normal left atrial (LA) segmental longitudinal funetion using speckle tracking echocardiography (STE). Methods: LA segmental longitudinal strain rates (SRs) were analyzed from apical four-and two-chamber views in 44 normals during left ventricular systolic (SRS) ,early diastolic (SR-E) and late diastolic (SR-A) phase using STE technique. LA segmenlal longitudinal SRs of the four walls ( septal, lateral, inferior and anterior) and the three levels (basal, middle and roof) were compared. Results :SR-S and SR-A of the inferior wall were the highest, septal and anterior walls were the lowest, while lateral SR-S and SR-A were in the middle at the basal and middle levels comparing the four walls (P < 0. 05 for all). SR-E was not different among the four walls at the same levels. The basal SR-S and SR-E of the inferior [ SR-S: (2. 22 ± 0. 64 ) and SR-E: ( -1. 69 ± 0. 70 ) ] and lateral wails [ SR-S: (2. 00 ± 0. 53 ) and SRE: ( -1. 62 ± 0. 57 ) ] were higher than the roof segments [ inferior SR-S: (1. 71 ± 0. 65 ) and lateral
Passerini, R; Seeber, B; Flükiger, R
The Young's modulus and fracture stress of isolated Bi,Pb(2223) filaments were deduced from three-point bending tests performed at different stages of the tapes preparation. These results were introduced in the model describing the evolution of critical current of tapes submitted to a longitudinal strain in view to predict their irreversible strain limit epsilon sub i sub r sub r. These calculated irreversible strain limits were compared to measured values, taken from a set of tapes made with different filling factors and composite matrices. This experiment shows that the predicted irreversible strain limits correspond to the measured ones. Presenting the I sub c behaviour of highly stressed tapes in a magnetic field, we discuss the evolution of the ratio I sup s sup t sup r sup o sup n sup g sub c sub 0 /I sub c sub 0 versus strain. This value, representative of the fraction of the critical current attributed to strongly connected grains, increases significantly during the crack formation regime at epsilon >...
The Young's modulus and fracture stress of isolated Bi,Pb(2223) filaments were deduced from three-point bending tests performed at different stages of the tapes preparation. These results were introduced in the model describing the evolution of critical current of tapes submitted to a longitudinal strain in view to predict their irreversible strain limit εirr. These calculated irreversible strain limits were compared to measured values, taken from a set of tapes made with different filling factors and composite matrices. This experiment shows that the predicted irreversible strain limits correspond to the measured ones. Presenting the Ic behaviour of highly stressed tapes in a magnetic field, we discuss the evolution of the ratio Istrongc0/Ic0 versus strain. This value, representative of the fraction of the critical current attributed to strongly connected grains, increases significantly during the crack formation regime at ε > εirr. This indicates that mechanically weak links correspond to electromagnetically weak ones. This result is further confirmed by comparing the modulus of rupture obtained in single filaments extracted from tapes with different Ic values
D'Ascenzi, F; Cameli, M; Lisi, M; Zacà, V; Natali, B; Malandrino, A; Benincasa, S; Catanese, S; Causarano, A; Mondillo, S
Left atrial (LA) enlargement and improved myocardial diastolic properties are a component of athlete's heart. We performed a longitudinal study involving adolescent athletes to investigate the impact of training on LA remodelling and diastolic function. 21 competitive adolescent soccer players were enrolled and engaged in an 8-month training program. Echocardiographic analysis was performed at baseline, after 4 and 8 months. We assessed diastolic function by Doppler tissue imaging and we analyzed LA adaptations by 2D speckle-tracking echocardiography. After 4 months, LA mean volume index significantly increased (Δ=5.47 ± 4.38 mL/m2, p ≤ 0.0001). After 8 months, a further increase occurred (Δ=8.95 ± 4.47 mL/m2, p ≤ 0.0001). A higher E velocity (p=0.001; p=0.001), a greater E/A ratio (p=0.002; p=0.0009), a higher e' peak (p= 0.005; p=0.001), and a greater e'/a' ratio (p=0.01; p=0.0006) were observed at 4 and at 8 months, respectively. E/e' ratio significantly decreased after 8 months (p ≤ 0.005). Global peak atrial longitudinal strain and global peak atrial contraction strain values significantly decreased after 8 months (p=0.0004, p=0.01, respectively). An 8-month training program is associated with LA dimensional and functional training-specific adaptations in competitive adolescent soccer players. Myocardial diastolic properties can improve after training also in subjects already presenting with features of athlete's heart. PMID:22562745
Lip, Gregory Y H; Fauchier, Laurent; Freedman, Saul B; Van Gelder, Isabelle; Natale, Andrea; Gianni, Carola; Nattel, Stanley; Potpara, Tatjana; Rienstra, Michiel; Tse, Hung-Fat; Lane, Deirdre A
Atrial fibrillation (AF) is the most common sustained cardiac rhythm disorder, and increases in prevalence with increasing age and the number of cardiovascular comorbidities. AF is characterized by a rapid and irregular heartbeat that can be asymptomatic or lead to symptoms such as palpitations, dys
Olesen, Morten S; Nielsen, Morten W; Haunsø, Stig;
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...
... Find People About NINDS NINDS Atrial Fibrillation and Stroke Information Page Table of Contents (click to jump ... done? Clinical Trials What is Atrial Fibrillation and Stroke? Atrial fibrillation (AF) describes the rapid, irregular beating ...
... Topics » Atrial Fibrillation » Living With Atrial Fibrillation Explore Atrial Fibrillation What Is... Types Other Names Causes Who Is at Risk Signs & Symptoms Diagnosis Treatments Prevention Living With Clinical Trials Links Related Topics Arrhythmia ...
Borre, Alicia; Kliewer, Wendy
Although poor parenting practices place youth living in under resourced communities at heightened risk for adjustment difficulties, less is known about what influences parenting practices in those communities. The present study examines prospective linkages between three latent constructs: parental strain, mental health problems and parenting practices. Parental victimization by community violence and life stressors were indicative of parental strain; depressive, anxious, and hostile symptoms...
Dunn, Nick; Inskip, Hazel; Kendrick, Tony; Oestmann, Anne; Barnett, Jane; Godfrey, Keith; Cooper, Cyrus
Background Social and financial environment has an influence on the incidence of depression. We studied perceived financial strain as a risk factor for development of depression among a large cohort of young women in Southampton, UK.
We report that atrial natriuretic factor (ANF) inhibits electrically induced cholinergic twitches of longitudinal muscle in whole intestinal segments and myenteric-plexus longitudinal muscle (MPLM) strips from the guinea pig ileum. To elucidate the possible presynaptic mechanism of ANF's action, we studied spontaneous and stimulation-evoked radiolabeled acetylcholine (ACh) outflow from MPLM after incubation with [3H]choline. We developed a method of mounting and treating MPLM preparations, which allowed us, at the same time, to record isometric contractions and to determine [3H]ACh outflow upon electrical stimulation by a train of three pulses. ANF (5 x 10-8M), norepinephrine (2 x 10-7) M and 8-bromoguanosine 3':5'-cyclic monophosphate (10-3 M) in nearly equieffective concentrations caused a similar inhibition of cholinergic twitches. However, ANF had no effect on [3H]ACh outflow, whereas norepinephrine was found to suppress [3H]ACh outflow and 8-bromoguanosine 3':5'-cGMP to enhanced [3H]ACh outflow. ANF (5 x 10-8 M) caused a 7.0-fold increase of cGMP over control values, predominantly in muscle layers, whereas Escherichia coli heat-stable toxin (12.5 U/ml) elicited a 35-fold increment of cGMP in the extramuscular layer. Thus, ANF is able to elevate cGMP in intestinal smooth muscle and to inhibit cholinergic contractions of MPLM. This inhibition is mimicked by exogenous cGMP and by endogenously generated cyclic nucleotides. We suggest that the depressive action of ANF on cholinergic contractions of MPLM is mediated via its postsynaptic impact implicating elevation of cGMP in smooth muscle
Sengeløv, Morten; Jørgensen, Peter Godsk; Jensen, Jan Skov;
Objectives: The purpose of this study was to investigate the prognostic value of global longitudinal strain (GLS) in heart failure with reduced ejection fraction (HFrEF) patients in relation to all-cause mortality. Background: Measurement of myocardial deformation by 2-dimensional speckle tracking...... failure clinic. The echocardiographic images were analyzed, and conventional and novel echocardiographic parameters were obtained. Results: Many of the conventional echocardiographic parameters proved to be predictors of mortality. However, GLS remained an independent predictor of mortality in the...... multivariable model after adjusting for age, sex, body mass index, total cholesterol, mean arterial pressure, heart rate, ischemic cardiomyopathy, percutaneous transluminal coronary angioplasty, coronary artery bypass graft surgery, noninsulin dependent diabetes mellitus, and conventional echocardiographic...
Full Text Available Background: The right ventricular (RV dyssynchrony has not been studied extensively and the existing literature has established the effect of cardiac resynchronization therapy (CRT on the left ventricular (LV dyssynchrony, but there is a dearth of data on the effect of CRT on the forgotten ventricle. We sought to evaluate the presence of mechanical right ventricular dyssynchrony in patients with systolic heart failure, selected for CRT, and track the changes early afterward utilizing the longitudinal strain analysis.Methods: Thirty-six patients with severe left ventricular systolic dysfunction, candidated for CRT, were enrolled in this study. Mechanical dyssynchrony was assessed using tissue Doppler echocardiography. The time interval between the onset of the QRS to the peak systolic longitudinal strain at the RV free wall and the septum was obtained. The RV mechanical delay was calculated as the absolute value of the difference in the time-to-peak measurements between the RV and septum. The RV dyssynchrony was defined as the calculated delay in strain imaging, which was ± 2 SD above the mean value for the control subjects (20 cases. The RV function was evaluated using the RV fractional area change (RVFAC, tricuspid annulus plane systolic excursion (TAPSE, and peak systolic strain values of the RV free wall. Four to 7 days after CRT implantation, echocardiographic reevaluations were done.Results: The calculated cut-off value for the RV dyssynchrony was 41.5 msec, according to which the pre-CRT analysis specified two patient groups: Group 1 (16 cases with RV dyssynchrony and Group 2 (20 patients without RV dyssynchrony. Significant improvement in the RV dyssynchrony was noted in Group 1 after CRT (30 ± 28.9 msec vs. 68.8 ± 21 msec; p value < 0.01 vs. 14 ± 10 msec vs. 19 ± 16.5 msec; p value = 0.18 respectively. A significant correlation was found between the severity of the RV dyssynchrony and peak systolic strain in the RV free wall (r = -0
DRAPKINA O.M.; A. V. Emelyanov
Mechanisms of atrial fibrosis including the role of serotonin in the development of this lesion in patients with atrial fibrillation are presented. New approaches to the treatment of atrial fibrillation aimed at atrial fibrosis reduction are discussed.
Farrokh, Babak; AbdulRahim, Nur Aida; Segal, Ken; Fan, Terry; Jones, Justin; Hodges, Ken; Mashni, Noah; Garg, Naman; Sang, Alex; Gifford, Dawn; Froggatt, Mark
Three means (i.e., typical foil strain gages, fiber optic sensors, and a digital image correlation (DIC) system) were implemented to measure strains on the back and front surfaces of a longitudinally jointed curved test article subjected to edge-wise compression testing, at NASA Goddard Space Flight Center, according to ASTM C364. The Pre-test finite element analysis (FEA) was conducted to assess ultimate failure load and predict strain distribution pattern throughout the test coupon. The predicted strain pattern contours were then utilized as guidelines for installing the strain measurement instrumentations. The strain gages and fiber optic sensors were bonded on the specimen at locations with nearly the same strain values, as close as possible to each other, so that, comparisons between the measured strains by strain gages and fiber optic sensors, as well as the DIC system are justified. The test article was loaded to failure (at approximately 38 kips), at the strain value of approximately 10,000mu epsilon As a part of this study, the validity of the measured strains by fiber optic sensors is examined against the strain gage and DIC data, and also will be compared with FEA predictions.
Dreiden, G. V.; Khusnutdinova, K. R.; Samsonov, A. M.; Semenova, I. V.
We study the effect of two types of adhesive bonding on the propagation of a localized longitudinal strain wave in two- and three-layered elastic bars. The detectable variation in the decay rate of the wave at relatively long distances of propagation is observed. It is proposed that such variation can be used as an indicator of the type of an interface.
Lip, Gregory Y H; Fauchier, Laurent; Freedman, Saul B; Van Gelder, Isabelle; Natale, Andrea; Gianni, Carola; Nattel, Stanley; Potpara, Tatjana; Rienstra, Michiel; Tse, Hung-Fat; Lane, Deirdre A
Atrial fibrillation (AF) is the most common sustained cardiac rhythm disorder, and increases in prevalence with increasing age and the number of cardiovascular comorbidities. AF is characterized by a rapid and irregular heartbeat that can be asymptomatic or lead to symptoms such as palpitations, dyspnoea and dizziness. The condition can also be associated with serious complications, including an increased risk of stroke. Important recent developments in the clinical epidemiology and management of AF have informed our approach to this arrhythmia. This Primer provides a comprehensive overview of AF, including its epidemiology, mechanisms and pathophysiology, diagnosis, screening, prevention and management. Management strategies, including stroke prevention, rate control and rhythm control, are considered. We also address quality of life issues and provide an outlook on future developments and ongoing clinical trials in managing this common arrhythmia. PMID:27159789
Wang, Yi; Hou, Dailun; Ma, Rongchuan; Ding, Geqi; Yin, Lixue; Zhang, Mei
Background Whether left atrial (LA) functional abnormalities already exist when the LA is of normal size is unknown. The aim of this study was to explore LA energy loss and mechanics changes using vector flow mapping (VFM) and two-dimensional tissue tracking (2DTT) echocardiography in patients with diabetes and normal LA size. Material/Methods This study included 47 normotensive patients with diabetes and 45 controls. The following indexes were measured: LA energy loss during systole (LAELs), early diastole (LAELed), and atrial contraction (LAELac); atrial longitudinal strain during systole (SLAs), early diastole (SLAed) and late diastole (SLAac); and peak LA strain rate during systole (SRLAs), early diastole (SRLAed), and atrial contraction (SRLAac). Results The LAELs and LAELed decreased in diabetic patients compared with controls (P=0.002, P<0.01, respectively), whereas the LAELac increased in diabetic patients (P<0.001). The SLAs, SLAed, SRLAs, and SRLAed (all P<0.01) were all lower in diabetic patients than in controls. However, there was no difference in the SLAac and SRLAac between the two groups. Multivariate regression analysis showed that the LAELs, LAELac, and SRLAs were independently associated with HbA1c in the whole study population. Conclusions LA energy loss and deformation mechanics are already impaired in diabetic patients with normal LA size and the long-term parameter of glycemic control was correlated with them. VFM combined with 2DTT might be a promising tool for the early detection of LA dysfunction caused by impaired glucose metabolism. PMID:27005947
Efeitos da idade e classe diamétrica na deformação residual longitudinal em árvores de Eucalyptus dunnii maiden Age and diametric class effects on longitudinal residual strain in Eucalyptus dunnii trees
Paulo Fernando Trugilho
Full Text Available O objetivo do trabalho foi avaliar os efeitos da idade e da classe diamétrica nos níveis das tensões de crescimento longitudinal em árvores de Eucalyptus dunnii oriundas de plantio comercial. O material avaliado foi procedente da Empresa Procopiak Compensados e Embalagens S.A., localizada no município de Canoinhas, Santa Catarina. Os níveis de tensão de crescimento foram mensurados indiretamente pelo método do "CIRAD-Forêt". Os resultados indicaram que os níveis da deformação residual longitudinal (DRL apresentaram tendência de aumento linear com a idade. O efeito da classe diamétrica evidenciou correlação negativa com a DRL aos 8 e 13 anos de idade.This research aims at evaluating the age and diametric class effects on levels of longitudinal residual strain in trees of Eucalyptus dunnii originated from commercial plantation. The appraised material came from Procopiak Company-Plywood and Package, located in Canoinhas, State of Santa Catarina-Brazil. The growth stress levels were measured indirectly through the "CIRAD-Forêt" method. The results indicated that the levels of longitudinal residual strain (DRL showed a tendency for linear increase with age. The diametric class effect gave negative correlation with DRL for 8 and 13- year old trees.
D'Ascenzi, Flavio; Cameli, Matteo; Padeletti, Margherita; Lisi, Matteo; Zacà, Valerio; Natali, Benedetta; Malandrino, Angela; Alvino, Federico; Morelli, Massimo; Vassallo, Gian Maria; Meniconi, Cosetta; Bonifazi, Marco; Causarano, Andrea; Mondillo, Sergio
Although many echocardiographic studies are available about the adaptation of left ventricle to intensive training, right heart function has been poorly investigated and no data are available about the right atrial (RA) function in top-level athletes. The aim of the study was to investigate RA function and dimension by standard echocardiography and 2D speckle tracking echocardiography (STE). One hundred top-levels athletes were recruited from professional sports team and were compared with 78 normal subjects. Athletes during an off-training period or during prolonged forced rest resulting from injuries were excluded. Top-level athletes had higher BSA as compared with controls and, as expected, a lower resting heart rate (p ≤ 0.001). RA area, volume, and volume index were significantly greater in athletes than in controls (p ≤ 0.001). This increase was associated with greater right ventricular and inferior vena cava diameters (p ≤ 0.001). Peak atrial longitudinal strain and peak atrial contraction strain values were significantly lower in athletes in comparison with controls (40.92 ± 9.86% vs. 48.00 ± 12.68%, p ≤ 0.001; 13.05 ± 4.84% vs. 15.99 ± 5.74%, p ≤ 0.001, respectively). Interestingly, while athletes presented a higher E/A ratio (p ≤ 0.001) and a lower peak A velocity (p ≤ 0.001), the E/e' ratio did not differ between the two groups. In top-level athletes the RA presents a physiological adaptation to intensive exercise conditioning which determines not only a morphological but also a functional remodeling. We reported for the first time reference values of RA strain in elite athletes, demonstrating that 2D STE is a useful tool to investigate RA longitudinal myocardial deformation dynamics in athlete's heart. PMID:22588713
... 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 ...
Full Text Available In order to evaluate the health status of continuous welded rail accurately, a deduction on the FBG sensing principle has been made with regard to the temperature variation of test specimens under different constraint conditions. A long seamless rail testing solution and its on-site application are designed based on this deduction. According to the verification experiments of sensing principle inside, the effect of the reference temperature on the FBG temperature and strain sensitivity coefficient within −30°C~30°C is not higher than 0.05%; the maximum relative error of single point between the tested and theoretical results of test specimen under constrained condition is 3.2%; and the maximum relative error of slopes of fitted straight lines based on the tested and theoretical results within the entire test temperature range is 2.3%, verifying the deduced FBG sensing principle with regard to the test specimen under constrained condition. The maximum error of the longitudinal temperature force between the on-site tested results and calculated results in long seamless rails is only 6.1 kN, the corresponding rail temperature variation is 0.3°C, and the accumulated error is controllable within 5%.
Lip, Gregory Y. H.; Watson, Timothy
Acute atrial fibrillation is rapid, irregular, and chaotic atrial activity of less than 48 hours' duration. It resolves spontaneously within 24 to 48 hours in over 50% of people. In this review we have included studies on patients with onset up to 7 days previously. Risk factors for acute atrial fibrillation include increasing age, CVD, alcohol abuse, diabetes, and lung disease.Acute atrial fibrillation increases the risk of stroke and heart failure.
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 circu...
... Pressure High Blood Pressure Tools & Resources Stroke More Atrial Fibrillation in Children Updated:Jul 18,2016 Does your ... content was last reviewed on 04/16/14. Atrial Fibrillation • Introduction • What is Atrial Fibrillation? • Why AFib Matters • ...
Atrial Fibrillation Atrial fibrillation, often called AFib or AF, is the most common type of heart arrhythmia. An arrhythmia is when the ... Atrium Sinoatrial Node (pacemaker) Atrioventricular Node Left Atrium Atrial Fibrillation AFib Facts 1 • An estimated 2.7–6. ...
... page from the NHLBI on Twitter. How Is Atrial Fibrillation Treated? Treatment for atrial fibrillation (AF) depends on ... too much thyroid hormone). Who Needs Treatment for Atrial Fibrillation? People who have AF but don't have ...
... Atrial Fibrillation » How Is Atrial Fibrillation Diagnosed? Explore Atrial Fibrillation What Is... Types Other Names Causes Who Is at Risk Signs & Symptoms Diagnosis Treatments Prevention Living With Clinical Trials Links Related Topics Arrhythmia ...
Terranova, Paolo; Severgnini, Barbara; Valli, Paolo; Dell'Orto, Simonetta; Greco, Enrico Maria
Pacing prevention algorithms have been introduced in order to maximize the benefits of atrial pacing in atrial fibrillation prevention. It has been demonstrated that algorithms actually keep overdrive atrial pacing, reduce atrial premature contractions, and prevent short-long atrial cycle phenomenon, with good patient tolerance. However, clinical studies showed inconsistent benefits on clinical endpoints such as atrial fibrillation burden. Factors which may be responsible for neutral results ...
Li-Wei Lo, MD; Shih-Ann Chen, MD
Full Text Available Radiofrequency catheter ablation procedures are considered a reasonable option for patients with symptomatic, drug refractory atrial fibrillation (AF. Ablation procedures have been reported to effectively restore sinus rhythm and provide long-term relief of symptoms. Both electrical and structural remodeling occurs with AF. A reversal of the electrical remodeling develops within 1 week after restoration to sinus rhythm following the catheter ablation. The recovery rate is faster in the right atrium than the left atrium. Reverse structural remodeling takes longer and is still present 2 to 4 months after restoration of sinus rhythm. The left atrial transport function also improves after successful catheter ablation of AF. Left atrial strain surveys from echocardiography are able to identify patients who respond to catheter ablation with significant reverse remodeling after ablation. Pre-procedural delayed enhancement magnetic resonance imaging is also able to determine the degree of atrial fibrosis and is another tool to predict the reverse remodeling after ablation. The remodeling process is complex if recurrence develops after ablation. Recent evidence shows that a combined reverse electrical and structural remodeling occurs after ablation of chronic AF when recurrence is paroxysmal AF. Progressive electrical remodeling without any structural remodeling develops in those with recurrence involving chronic AF. Whether progressive atrial remodeling is the cause or consequence during the recurrence of AF remains obscure and requires further study.
Llinares Llopis, Raúl; Igual García, Jorge
[EN] Atrial fibrillation disorders are one of the main arrhythmias of the elderly. The atrial and ventricular activities are decoupled during an atrial fibrillation episode, and very rapid and irregular waves replace the usual atrial P-wave in a normal sinus rhythm electrocardiogram (ECG). The estimation of these wavelets is a must for clinical analysis. We propose a new approach to this problem focused on the quasiperiodicity of these wavelets. Atrial activity is characterized by...
Mahsa, Taheri; Barros, Joaquim A. O.; Salehian, Hamidreza
A close form solution is developed for the prediction of the moment-curvature relationship of cross sections of fiber reinforced concrete (FRC) elements failing in bending, and reinforced longitudinally with steel and fiber reinforced polymer (FRP) bars. The FRP bars are installed with the largest possible internal arm, e.g. with the minimum concrete cover that assures the bond conditions for a sound stress transfer from FRC to the FRP bars. The model is also able of simulating th...
. Consequently suboptimal tracking of the endocardial border may be a problem with STE. Assessment of 2D strain by STE has been applied to both ventricles and atria. The articles published in this issue of the journal demonstrate the value of Strain and strain rate imaging in detecting the subclinical atrial and ventricular dysfunction, besides reporting the normal value of right atrium deformation indices. In all, first three articles of this journal, measurement of ventricular and atrial deformation indices have been considered as a feasible and reproducible technique. Assessment of atrial deformation profiles using Doppler-derived strain imaging and STE has been recently proposed as an alternative method of exploring atrial function (7. Nonetheless, some potential technical difficulties are noteworthy. STE is not completely angle independent, since ultrasound images normally have better resolution along the ultrasound beam compared with the perpendicular direction. Newly developed three-dimensional speckle tracking (3DT method has been suggested as a simple, feasible, and reproducible method to measure longitudinal, circumferential and radial strains. Similar to other 2D imaging techniques, 3DT relies on good image quality and the major pitfall of 3D STE is its dependency on image quality. Nevertheless, it still requires rigorous validation and testing (8-10.
Increasing parts of the world are facing ageing societies with growing figures of morbidity and disability. Focus of attention for European countries is directed towards prevention of old age impairment. As considerable time is spent at work, preventative psychosocial work environment measures could be entry points for a healthier ageing. The aims of this study are to i) explore the impact of mid-life work strain on old age disability ii) to examine the independent effects of the work strain ...
Kapusta, L.; Mainzer, G.; Weiner, Z.; Deutsch, L.; Khoury, A.; Haddad, S.; Lorber, A.
BACKGROUND: Data on myocardial deformation during the internationally widely used second-trimester screening are scarce and confusing. Reference values of time to peak strain are missing. The aims of this study were to assess reference values derived from two-dimensional speckle-tracking echocardiog
Le Heuzey, Jean-Yves; Breithardt, Günter; Camm, John; Crijns, Harry; Dorian, Paul; Kowey, Peter R; Merioua, Ihsen; Prystowsky, Eric N; Schwartz, Peter J; Torp-Pedersen, Christian; Weintraub, William
The REgistry on Cardiac rhythm disORDers assessing the control of Atrial Fibrillation (RecordAF) is the first worldwide, 1-year observational, longitudinal study of the management of paroxysmal/persistent atrial fibrillation (AF) in recently diagnosed patients. The study was conducted at 532 site...
Steinberg, Benjamin A; Piccini, Jonathan P.
Atrial fibrillation increases the risk of stroke, which is a leading cause of death and disability worldwide. The use of oral anticoagulation in patients with atrial fibrillation at moderate or high risk of stroke, estimated by established criteria, improves outcomes. However, to ensure that the benefits exceed the risks of bleeding, appropriate patient selection is essential. Vitamin K antagonism has been the mainstay of treatment; however, newer drugs with novel mechanisms are also availabl...
Frost, L.; Frost, P.; Vestergaard, P.
Background and Aims: Excessive sporting activities have been associated with risk of atrial fibrillation. To study if work related physical activity also confers risk of atrial fibrillation or flutter, the association between work related physical strain and the risk of a hospital discharge diagnosis (inpatient as well as outpatient) of atrial fibrillation or flutter was examined.
Paulo Fernando Trugilho; Sebastião Carlos da Silva Rosado; José Tarcísio Lima; Franciane Andrade de Pádua; Marcos Aurélio Mathias de Souza
The objectives of the present study were: a) to verify the variation of DRL between two longitudinal position (1,3 m and 3 m height) in the stem of trees; b) to determine the relationship between DRL with diameter at 1,3 m of soil height (DBH) and total height (h) and; d) to estimate genetic and phenotypic parameters of the tudied characteristics. Eleven natural hybrid Eucalyptus clones were used. These clones were sampled at the Fazenda Riacho, which belongs to the Companhia Mineira de Metai...
Full Text Available Purpose. The effects of mechanical ventilation (MV on speckle tracking echocardiography- (STE-derived variables are not elucidated. The aim of the study was to evaluate the effects of positive end-expiratory pressure (PEEP ventilation on 4-chamber longitudinal strain (LS analysis by STE. Methods. We studied 20 patients admitted to a mixed intensive care unit who required intubation for MV and PEEP titration due to hypoxia. STE was performed at three times: (T1 PEEP = 5 cmH2O; (T2 PEEP = 10 cmH2O; and (T3 PEEP = 15 cmH2O. STE analysis was performed offline using a dedicated software (XStrain MyLab 70 Xvision, Esaote. Results. Left peak atrial-longitudinal strain (LS was significantly reduced from T1 to T2 and from T2 to T3 (. Right peak atrial-LS and right ventricular-LS showed a significant reduction only at T3 (. Left ventricular-LS did not change significantly during titration of PEEP. Cardiac chambers’ volumes showed a significant reduction at higher levels of PEEP (. Conclusions. We demonstrated for the first time that incremental PEEP affects myocardial strain values obtained with STE in intubated critically ill patients. Whenever performing STE in mechanically ventilated patients, care must be taken when PEEP is higher than 10 cmH2O to avoid misinterpreting data and making erroneous decisions.
Evrard, P.; Sakalihasan, Natzi; R. Garcia; Van Laere, Anne-Sophie; Patterson, B.
After conversion of atrial fibrillation, it is important to maintain sinus rhythm. In addition antiarrhythmic drugs, biatrial resynchronization seems to prevent recurrences of atrial fibrillation in patients with interatrial conduction block: local experience.
Paulo Fernando Trugilho
Full Text Available The objectives of the present study were: a to verify the variation of DRL between two longitudinal position (1,3 m and 3 m height in the stem of trees; b to determine the relationship between DRL with diameter at 1,3 m of soil height (DBH and total height (h and; d to estimate genetic and phenotypic parameters of the tudied characteristics. Eleven natural hybrid Eucalyptus clones were used. These clones were sampled at the Fazenda Riacho, which belongs to the Companhia Mineira de Metais of the Votorantim Group, located at Paracatu, region Northwest of Minas Gerais State, Brazil. According to the results the extensometer was efficient and fast for the measurement of DRL, becoming a useful tool to identify trees with different intensities of growth stresses. The differences of DRL amongst clones were statistically significant, however the differences of DRL between the two longitudinal positions in the stem were not statistically significant. There was no significant statistical correlation between DRL and growth characteristics of the trees. Both DRL and growth characteristics resulted in high genetic heritability, indicating that these characteristics are under high genetic control, and therefore with potential for genetic improvement.
Everett, Thomas H; Olgin, Jeffrey E.
Atrial fibrillation (AF) is commonly associated with congestive heart failure (CHF), and CHF has been shown to be associated with atrial structural remodeling resulting in fibrosis. This atrial interstitial fibrosis has been seen in patients with CHF and animal models of pacing induced heart failure. With atrial fibrosis, conduction abnormalities result in an increase in AF vulnerability. The mechanism of AF that is associated with CHF is still under debate as both focal and reentrant mechani...
... page from the NHLBI on Twitter. How Can Atrial Fibrillation Be Prevented? Following a healthy lifestyle and taking ... risk for heart disease may help you prevent atrial fibrillation (AF). These steps include: Following a heart healthy ...
Jalife, José; Kaur, Kuljeet
The fundamental mechanisms governing the perpetuation of atrial fibrillation (AF), the most common arrhythmia seen in clinical practice, are poorly understood, which explains in part why AF prevention and treatment remain suboptimal. Although some clinical parameters have been identified as predicting a transition from paroxysmal to persistent AF in some patients, the molecular, electrophysiological, and inflammation changes leading to such a progression have not been described in detail. Oxidative stress, atrial dilatation, calcium overload, inflammation, microRNAs, and myofibroblast activation are all thought to be involved in AF-induced atrial remodeling. However, it is unknown to what extent and at which time points such alterations influence the remodeling process that perpetuates AF. Here we postulate a working model that might open new pathways for future investigation into mechanisms of AF perpetuation. We start from the premise that the progression to AF perpetuation is the result of interplay among manifold signaling pathways with differing kinetics. Some such pathways have relatively fast kinetics (e.g., oxidative stress-mediated shortening of refractory period); others likely depend on molecular processes with slower kinetics (e.g., transcriptional changes in myocyte ion channel protein expression mediated through inflammation and fibroblast activation). We stress the need to fully understand the relationships among such pathways should one hope to identify novel, truly effective targets for AF therapy and prevention. PMID:25661032
Atrial flutter (AFL) is a common arrhythmia in clinical practice. Several experimental models such as tricuspid regurgitation model, tricuspid ring model, sterile pericarditis model and atrial crush injury model have provided important information about reentrant circuit and can test the effect of antiarrhythmic drugs. Human atrial flutter has typical and atypical forms. Typical atrial flutter rotates around tricuspid annulus and uses the crista terminalis and sometimes sinus venosa as the ...
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 absence of P-waves, and an irregular heart rate. Symptoms of atrial fibrillation include palpitations, dyspnea, reduced exercise capacity, chest pain and dizziness, but it often goes without symptoms. A...
The only major and potentially fatal risk for patients with atrial fibrillation is the development of systemic thromboembolism. Stroke occurs five times more frequently in patients with atrial fibrillation than in comparable patients in sinus rhythm. The yearly incidence of stroke in atrial fibrilla
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.
Steinberg, Benjamin A; Piccini, Jonathan P
Atrial fibrillation increases the risk of stroke, which is a leading cause of death and disability worldwide. The use of oral anticoagulation in patients with atrial fibrillation at moderate or high risk of stroke, estimated by established criteria, improves outcomes. However, to ensure that the benefits exceed the risks of bleeding, appropriate patient selection is essential. Vitamin K antagonism has been the mainstay of treatment; however, newer drugs with novel mechanisms are also available. These novel oral anticoagulants (direct thrombin inhibitors and factor Xa inhibitors) obviate many of warfarin's shortcomings, and they have demonstrated safety and efficacy in large randomized trials of patients with non-valvular atrial fibrillation. However, the management of patients taking warfarin or novel agents remains a clinical challenge. There are several important considerations when selecting anticoagulant therapy for patients with atrial fibrillation. This review will discuss the rationale for anticoagulation in patients with atrial fibrillation; risk stratification for treatment; available agents; the appropriate implementation of these agents; and additional, specific clinical considerations for treatment. PMID:24733535
Full Text Available OBJECTIVES: We assessed the value of speckle tracking imaging performed early after a first ST-segment elevation myocardial infarction (STEMI in order to predict infarct size and functional recovery at 3-month follow-up. METHODS: 44 patients with STEMI who underwent revascularization within 12 h of symptom onset were prospectively enrolled. Echocardiography was performed 3.9 ± 1.2 days after myocardial reperfusion, assessing circumferential (CGS, radial (RGS, and longitudinal global (GLS strains. Late gadolinium-enhanced cardiac magnetic imaging (CMR, for assessing cardiac function, infarct size, and microvascular obstruction (MVO, was conducted 5.6 ± 2.5 days and 99.4 ± 4.6 days after myocardial reperfusion. RESULTS: GLS was evaluable in 97% of the patients, while CGS and RGS could be assessed in 85%. Infarct size significantly correlated with GLS (R = 0.601, p-6.0% within the infarcted area exhibited 96% specificity and 61% sensitivity for predicting the persistence of akinesia (≥ 3 segments at 3-month follow-up. CONCLUSIONS: Speckle-tracking strain imaging performed early after a STEMI is easy-to-use as a marker for persistent akinetic territories at 3 months. In addition, GLS correlated significantly with MVO and final infarct size, both parameters being relevant post-MI prognostic factors, usually obtained via CMR.
Zhang wei; Yang guirong; Zheng zhaotong; Wang sujia; Zhang yun
@@ Objective Integrin β1 regulates cell to cell and cell to extracellualr matrix interaction in heart. however, its pathop hysiological role in atrial fibrillation is unclear. The purpose of t his study was to determine whether atrial structural remodeling during atrial fibrillation is associated with altered integrinβ1.
Global longitudinal strain is an independent predictor of cardiovascular events in patients with maintenance hemodialysis: a prospective study using three-dimensional speckle tracking echocardiography.
Sun, Minmin; Kang, Yu; Cheng, Leilei; Pan, Cuizhen; Cao, Xuesen; Yao, Haohua; Dong, Lili; Shu, Xianhong
The aim of this study was to investigate subclinical LV changes in patients with maintenance hemodialysis (MHD) using three-dimensional speckle-tracking echocardiography (3DSTE) and to explore its prognostic value. A total of 88 individuals were consecutively enrolled, including 66 subjects with MHD and 22 age- and sex-matched controls. Conventional and Real-time three-dimensional echocardiography was performed and analyzed. Left ventricular volume, strain and time parameters were calculated and compared. The MHD cohort was then followed to record cardiovascular events (CVE). Univariate and multivariate logistic regression analysis was used to identify independent predictors of CVE. Compared with the controls, MHD patients had significantly lower global longitudinal and radial strain (GLS and GRS), and LVEF (GLS: -17.0 ± 2.3 vs -18.8 ± 2.3 %; GRS: 37.0 ± 3.5 vs 39.4 ± 3.4 %; LVEF: 57.3 ± 4.2 vs 59.5 ± 3.5 %, p MHD group (T-msv: 38.1 ± 5.2 vs 41.4 ± 6.4 %; T-ls: 38.1 ± 4.6 vs 42.1 ± 6.8 %, p MHD group was significant larger than that of the controls (6.4 ± 1.5 vs 4.9 ± 1.8 %, p MHD patients with preserved LVEF. GLS and LVMi are two important predictors of CVE in MHD patients. Strain assessment in MHD patients may contribute to better vascular risk stratification. PMID:26768275
BACKGROUND: Atrial fibrillation is the most common cardiac dysrhythmia and left atrial size is an important factor in the development of atrial fibrillation. In the presence of atrial fibrillation an increase in left atrial size is associated with increased risk of stroke as well as increased morbidity and mortality. In this context, this study entitled “relation between left atrial size and atrial fibrillation in different diseases” was undertaken to study the left atrial size in different d...
Llinares, Raul; Igual, Jorge
Atrial fibrillation disorders are one of the main arrhythmias of the elderly. The atrial and ventricular activities are decoupled during an atrial fibrillation episode, and very rapid and irregular waves replace the usual atrial P-wave in a normal sinus rhythm electrocardiogram (ECG). The estimation of these wavelets is a must for clinical analysis. We propose a new approach to this problem focused on the quasiperiodicity of these wavelets. Atrial activity is characterized by a main atrial rhythm in the interval 3-12 Hz. It enables us to establish the problem as the separation of the original sources from the instantaneous linear combination of them recorded in the ECG or the extraction of only the atrial component exploiting the quasiperiodic feature of the atrial signal. This methodology implies the previous estimation of such main atrial period. We present two algorithms that separate and extract the atrial rhythm starting from a prior estimation of the main atrial frequency. The first one is an algebraic method based on the maximization of a cost function that measures the periodicity. The other one is an adaptive algorithm that exploits the decorrelation of the atrial and other signals diagonalizing the correlation matrices at multiple lags of the period of atrial activity. The algorithms are applied successfully to synthetic and real data. In simulated ECGs, the average correlation index obtained was 0.811 and 0.847, respectively. In real ECGs, the accuracy of the results was validated using spectral and temporal parameters. The average peak frequency and spectral concentration obtained were 5.550 and 5.554 Hz and 56.3 and 54.4%, respectively, and the kurtosis was 0.266 and 0.695. For validation purposes, we compared the proposed algorithms with established methods, obtaining better results for simulated and real registers.
Full Text Available The aim of the study was to investigate the effect of cyclic mechanical strain on differentiation markers in the presence or absence of dexamethasone. Human bone marrow stromal cells (BMSC from seven donors (32.5±6.2 years were cultivated with (D+ or without (D- dexamethasone. A cyclic mechanical strain with an elongation of 2% (D+2; D-2 or 8% (D+8; D-8 was applied for three days with a stimulation time of three times two hours each day. Levels of alkaline phosphatase (ALP and osteocalcin (OC were compared after time intervals of four and seven days. mRNA expression of Collagen I, III and Cbfa1 was investigated after one, four, and seven days. ALP levels were significantly increased in the D+8 group after four and seven days (147.1±6.3%; p<0.05 and 168.6±6,5%; p<0.03 and in the D-8 group after 7 days (197.4±10.4; p<0.04. Cyclic strain had a significant influence on ALP-secretion (F=7.5; p<0.01. In the D-8 group there was a significant increase in OC secretion after 4 days (140.9±12.5%; p<0.05.; p<0.01. The effect of stretching was significantly stronger than that of dexamethasone (F=17.2 vs. 1.8. Collagen I (Col I expression was upregulated in D+8 cultures after 4 days (215.0±53.3 p<0.04 and after seven days (166.7±55.7; p<0.04. Collagen III (Col III expression was upregulated in D+2 and D+8 cultures after 4 days (200.7±16.3 and 185.9±12.7; p<0.04 and after seven days (154.4±10.1 and 118.8±16.4; p<0.04. There was a significant increase of Cbfa1 expression in D+8 cultures at all investigated time intervals (day 1: 105.5±3.7%; day 4: 104.7±3.0%; day 7: 104.4±2.1%; p<0.03. Stretching (F=20.0; p<0.01 was a stronger contributor to Cbfa-1 expression than dexamethasone (F=12.1; p<0.01. Cyclical mechanical stimulation with 8% elongation increases ALP and OC levels and upregulates Col I and III synthesis and Cbfa1 expression. In the short term, cyclical stretching is a stronger differentiation factor than dexamethasone. Cyclical stretching
... regular beat. Certain cells in your heart make electric signals that cause the heart to contract and pump blood. These electrical signals show up on an elec- trocardiogram (ECG) recording. Your doctor can read your ECG to find out if the electric signals are normal. In atrial fibrillation (AFib), the ...
@@ Atrial fibrillation(AF) may occur in paroxysmaland persistent forms. It may be seen in normal subjects,particularly during emotional stress or follow-ing surgery,exercise, or acute alcoholic intoxication.It also may occur in patients with heart or lungdisease who develop acute hypoxia, hypercapnia,ormetabolic or hemodynamic derangements.
Kercheva, M.; Ryabova, T.; Ryabov, V.; Karpov, R.
The aim of this study was to assess the intraobserver reproducibility of parameters of standard and 2 dimensional speckle tracking echocardiography, dynamics of global longitudinal strain in patients with acute primary anterior STEMI. The study included 24 patients, mean age 58.46±10.2. Echocardiography with 2D speckle tracking imaging was performed on the 1st (T1), 7th (T2), 14th days (T3) after STEMI («Vivid E9»). Analysis of echocardiographic images was performed offline at the different periods by the two independent observers (EchoPac) - experienced and inexperienced. In order to assess the agreement between standard and 2D speckle tracking echocardiography, a correlation analysis (Pearson correlation, Spearman's rank correlation coefficient) and Bland-Altman analysis were undertaken. The 23 patients had urgent reperfusion therapy, 6 patients underwent primary PCI, 16 patients - PCI after successful fibrinolysis (68%). GLS and WMSI had the best intraobsever reproducibility. Dynamics of EDV LV, ESV LV, EF LV was without significant differences. Nevertheless, it was found positive dynamic of GLS: - 12.65±3.53 (T1), -13.61±3.81 (T2), -14.27±4.1 (T3), ppatients limits adverse postinfarction remodeling and preserves of global left ventricular contractility detected by the EF LV. However, GLS had the positive dynamics and improved to the 14th day.
Christiansen, Jon R; Massey, Richard; Dalen, Håvard; Kanellopoulos, Adriani; Hamre, Hanne; Fosså, Sophie D; Ruud, Ellen; Kiserud, Cecilie E; Aakhus, Svend
Measuring left ventricular (LV) global longitudinal strain (GLS) is recommended in screening of long-term cancer survivors for cardiotoxicity. However, there are limited data on GLS in this setting, in particular in survivors with apparently normal LV function without risk factors of impaired GLS. In the present study, we measured GLS in 191 adult survivors of childhood lymphoma or acute lymphoblastic leukemia, with normal LV ejection fraction and fractional shortening (FS) and without known hypertension, diabetes mellitus, myocardial infarction, or stroke. We compared GLS in the survivors with 180 controls. Mean GLS was -19.0 ± 2.2% in the survivor group and -21.4 ± 2.0% in the controls (p cancer treatment. Survivors treated with mediastinal radiotherapy had an odds ratio of impaired GLS of 5.2 (95% confidence interval 2.2 to 12) compared with other survivors. Survivors treated with cumulative anthracycline doses >300 mg/m(2) had an odds ratio of 4.8 (95% confidence interval 1.7 to 14) of impaired GLS. In conclusion, this study demonstrates a high proportion of LV dysfunction assessed by GLS in apparently healthy adult survivors of childhood cancer. Impaired GLS was associated with previous exposure to mediastinal radiotherapy and high doses of anthracyclines. The prognostic role of measuring GLS in this specific patient population should be examined in prospective studies. PMID:27296561
Auranen, Kari; Mehtälä, Juha; Tanskanen, Antti; S Kaltoft, Margit
The state of pneumococcal carriage-that is, pneumococcal colonization in the nasopharynx of healthy persons-represents a reservoir for the spread of pneumococci among individuals. In light of the introduction of new pneumococcal conjugate vaccines, further knowledge on the dynamics of pneumococcal carriage is important. Different serotypes (strains) of pneumococcus are known to compete with each other in colonizing human hosts. Understanding the strength and mode of between-serotype competition is important because of its implications for vaccine-induced changes in the ecology of pneumococcal carriage. Competition may work through reduced acquisition of new serotypes, due to concurrent carriage in the individual, or through enhanced clearance of serotypes in carriers who harbor more than 1 serotype simultaneously. The authors employed longitudinal data (1999-2001) on pneumococcal carriage in Danish day-care children to analyze between-serotype competition. The data included observations of carriage in children who had not been vaccinated against pneumococcus, and the level of pneumococcal antibiotic resistance and antibiotic usage in the community was very low. Clearance of any single serotype was not affected by simultaneous carriage of other serotypes. In contrast, acquisition of other serotypes in already-colonized hosts was weak (relative rate of acquisition = 0.09, 95% credible interval: 0.05, 0.15). PMID:19969530
Roberto A.Franken; Ronaldo F.Rosa; Silvio CM Santos
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.
刘晓丽; 姜笑梅; 殷亚方
In this paper, CIRAD-Foret method and strain gauge method were used to measure the longitudinal surface growth strains released from fallen woods. Comparison was also done between two methods for measurements at the same point (sawing grooves inside the position pins)and at two points. Results showed that the values obtained from the CIRAD-Foret method were bigger than those from strain gauge method. The former was 1.3 times as high as the latter for the measurement at two points, and it was 2.0 times as high as the latter for the measurement at the same point. There was no distinct difference in the longitudinal surface growth strains from strain gauge method with measuring way at the same point and two points. However, the differences were obvious for the strains from CIRAD-Foret method with two measuring ways. They indicated that there was little effect on the values from strain gauge method with measuring way at the same point or at two points, and that the measuring way would influence measured result when CIRAD-Foret method was applied. In general, in comparison with CIRAD-Foret method, strain gauge method was more stable.
Vergara, Pasquale; Della Bella, Paolo
Atrial fibrillation (AF) is associated with increases in the risk of mortality, congestive heart failure, and stroke. Medical treatment is aimed at preventing thrombo-embolic complications and reducing symptoms and consequences related to the arrhythmia. In the first section of this review, we discuss the principles of mainstream oral anticoagulant therapy and the possible advantages of the new oral anticoagulants. In the second section, we review the catheter ablation approaches to paroxysma...
Pêgo-Fernandes Paulo M.
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.
Ahmad, Yousif; YH Lip, Gregory
Patients with atrial fibrillation (AF) are at increased thromboembolic risk, and they suffer more severe strokes with worse outcomes. Most thromboembolic complications of AF are eminently preventable with oral anticoagulation, and the increasing numbers of AF patients mean antithrombotic therapy is the most crucial management aspect of this common arrhythmia. Despite the proven efficacy of warfarin, a string of limitations have meant that it is underused by physicians and patients alike. This...
Giorgi MA; Miguel LS
Mariano A Giorgi,1,2 Lucas San Miguel31Cardiology Service, Centro de Educación Médica e Investigaciones Clínicas “Norberto Quirno”, 2Department of Pharmacology, School of Medicine, Universidad Austral, 3Department of Cardiology and Cardiovascular Surgery, FLENI, Buenos Aires, ArgentinaAbstract: Warfarin is the traditional therapeutic option available to manage thromboembolic risk in atrial fibrillation. The hemorrhagic risk with warfarin de...
Francis E. Marchlinski
Full Text Available Atrial fibrillation (AF is a supraventricular tachyarrhythmia characterized by uncoordinated atrial activation. On the ECG fibrillatory (f waves (rapid oscillations with variable amplitude, shape and timing replace normal P waves. Ventricular response becomes irregular and rapid depending of the intrinsic electrophysiological properties of the AV node1 and the balance between vagal and sympathetic tone1. The presence of an irregularly pulse is a clinical sign that can be quickly and reliably identified in any healthcare situation and, indicates AF with a high sensitivity and specificity (95% and 75%, respectively. If the irregularity last for more than 20 seconds the specificity reaches 98% 2-4. Identification of AF can be done by using manual pulse palpation in those presenting with a variety of symptoms. It is desirable to check the blood pressure and pulse in all patients who present with breathlessness, dyspnea, palpitations, syncope, dizziness or chest discomfort. Furthermore, many patients presenting with an acute stroke are found to be in AF albeit asymptomatic with respect to non-neurologic complaints. The finding of a sustained irregular wide QRS complex tachycardia may be suspicious of AF conducted with bundle brunch aberrancy or over an accessory pathway, and in patients with A-V sequential pacemakers can reflect an inadequate configuration with ventricular tracking of sensed atrial activity.
Maharani, Nani; Kuwabara, Masanari; Hisatome, Ichiro
The importance of atrial fibrillation (AF) as a cause of mortality and morbidity has prompted research on its pathogenesis and treatment. Recognition of AF risk factors is essential to prevent it and reduce the risk of death. Hyperuricemia has been widely accepted to be associated with the incidence of paroxysmal or persistent AF, as well as to the risk of AF in post cardiovascular surgery patients. The possible explanations for this association have been based on their relation with either oxidative stress or inflammation. To investigate the link between hyperuricemia and AF, it is necessary to refer to hyperuricemia-induced atrial remodeling. So far, both ionic channel and structural remodeling caused by hyperuricemia might be plausible explanations for the occurrence of AF. Inhibition of xanthine oxidase and nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase, or the use of antioxidants, along with serum uric acid (SUA) level reduction to prevent inflammation, might be useful. Uric acid transporters (UATs) play a key role in the regulation of intracellular uric acid concentration. Intracellular rather than serum uric acid level is considered more important for the pathogenesis of AF. Identification of UATs expressed in cells is thus important, and targeting UATs might become a potential strategy to reduce the risk of hyperuricemia-induced atrial fibrillation. PMID:27396561
Spronk, Henri M H; De Jong, Anne Margreet; Verheule, Sander; De Boer, Hetty C; Maass, Alexander H; Lau, Dennis H; Rienstra, Michiel; van Hunnik, Arne; Kuiper, Marion; Lumeij, Stijn; Zeemering, Stef; Linz, Dominik; Kamphuisen, Pieter Willem; Ten Cate, Hugo; Crijns, Harry J; Van Gelder, Isabelle C; van Zonneveld, Anton Jan; Schotten, Ulrich
AIMS: Atrial fibrillation (AF) produces a hypercoagulable state. Stimulation of protease-activated receptors by coagulation factors provokes pro-fibrotic, pro-hypertrophic, and pro-inflammatory responses in a variety of tissues. We studied the effects of thrombin on atrial fibroblasts and tested the
Tzikas, Apostolos; Shakir, Samera; Gafoor, Sameer;
Aims: To investigate the safety, feasibility, and efficacy of left atrial appendage occlusion (LAAO) with the AMPLATZER Cardiac Plug (ACP) for stroke prevention in patients with atrial fibrillation (AF). Methods and results: Data from consecutive patients treated in 22 centres were collected. A...
Kercheva, M.; Ryabova, T.; Ryabov, V.; Karpov, R.
The aim of this study was to assess the intraobserver reproducibility of parameters of standard and 2 dimensional speckle tracking echocardiography, dynamics of global longitudinal strain in patients with acute primary anterior STEMI. The study included 24 patients, mean age 58.46±10.2. Echocardiography with 2D speckle tracking imaging was performed on the 1st (T1), 7th (T2), 14th days (T3) after STEMI («Vivid E9»). Analysis of echocardiographic images was performed offline at the different periods by the two independent observers (EchoPac) - experienced and inexperienced. In order to assess the agreement between standard and 2D speckle tracking echocardiography, a correlation analysis (Pearson correlation, Spearman's rank correlation coefficient) and Bland-Altman analysis were undertaken. The 23 patients had urgent reperfusion therapy, 6 patients underwent primary PCI, 16 patients - PCI after successful fibrinolysis (68%). GLS and WMSI had the best intraobsever reproducibility. Dynamics of EDV LV, ESV LV, EF LV was without significant differences. Nevertheless, it was found positive dynamic of GLS: - 12.65±3.53 (T1), -13.61±3.81 (T2), -14.27±4.1 (T3), p<0.05. GLS reduced 11.35% (p=0.0048) from T1 to T3. The best intraobserver reproducibility of parameters of 2 D speckle-tracking and standard echocardiography was revealed in GLS and WMSI. The modern management of STEMI patients limits adverse postinfarction remodeling and preserves of global left ventricular contractility detected by the EF LV. However, GLS had the positive dynamics and improved to the 14th day.
Remes, J.; Brakel, T.J. van; Bolotin, G.; Garber, C.; Jong, MM de; Veen, FH van der; Maessen, J.G.
OBJECTIVES: Atrial dilatation predisposes to atrial fibrillation. Although several animal models focus on the initiating mechanisms of atrial fibrillation in dilated atria, a model of left atrial overload resulting in persistent atrial fibrillation in nonanesthetized animals has not been presented t
HAN Wei; LI Wei-min; ZHOU Hong-yan; HUO Hong; WEI Na; DONG Guo; CAO Yong; ZHOU Guo; YANG Shu-sen
@@ Atrial fibrillation (AF) is one of the most common arrhythmias in clinical practice. AF results in electrophysiological alterations which involve increased atrial effective refractory period and atrial effective refractory period dispersion, reduced rate adaptation of atrial effective refractory period, and slowed atrial conduction.
John, Roy M; Kumar, Saurabh
Although sinus node dysfunction (SND) and atrial arrhythmias frequently coexist and interact, the putative mechanism linking the 2 remain unclear. Although SND is accompanied by atrial myocardial structural changes in the right atrium, atrial fibrillation (AF) is a disease of variable interactions between left atrial triggers and substrate most commonly of left atrial origin. Significant advances have been made in our understanding of the genetic and pathophysiologic mechanism underlying the development and progression of SND and AF. Although some patients manifest SND as a result of electric remodeling induced by periods of AF, others develop progressive atrial structural remodeling that gives rise to both conditions together. The treatment strategy will thus vary according to the predominant disease phenotype. Although catheter ablation will benefit patients with predominantly AF and secondary SND, cardiac pacing may be the mainstay of therapy for patients with predominant fibrotic atrial cardiomyopathy. This contemporary review summarizes current knowledge on sinus node pathophysiology with the broader goal of yielding insights into the complex relationship between sinus node disease and atrial arrhythmias. PMID:27166347
Michelle M Jennings; J Kevin Donahue
Atrial fibrillation significantly contributes to mortality and morbidity through increased risk of stroke, heart failure and myocardial infarcts. Investigations of mechanisms responsible for the development and maintenance of atrial fibrillation have highlighted the importance of gap junctional remodeling. Connexins 40 and 43, the major atrial gap junctional proteins, undergo considerable alterations in expression and localization in atrial fibrillation, creating an environment conducive to s...
Berglund, H; Boukter, S; Theodorsson, E; Vallin, H; Edhag, O
The aim of the present study was to determine whether left atrial size--a likely indicator of atrial stretching--correlates with the plasma concentration of atrial natriuretic peptide and whether this relation is different in patients in sinus rhythm and in those with atrial fibrillation. Arterial plasma concentrations of immunoreactive atrial natriuretic peptide (ir-ANP), adrenaline, noradrenaline, aldosterone, and vasopressin were measured in 13 patients in sinus rhythm without apparent hea...
Levy, T; Walker, S; Rex, S; Rochelle, J; Paul, V.
OBJECTIVE—To evaluate the incremental antifibrillatory effect of multisite atrial pacing compared with right atrial pacing in patients with drug refractory paroxysmal atrial fibrillation paced for arrhythmia prevention alone. METHODS—In 20 of these patients (mean (SD) age 64 (8) years; 14 female, six male), a single blinded randomised crossover study was performed to investigate the incremental benefit of one month of multisite atrial pacing compared with one month of right atrial pacing. Out...
方宁宁; 巩会平; 蒋桂花; 张运; 张薇
目的 应用应变/应变率技术评价超重及肥胖者左心房功能的变化.方法 30例超重者(28kg/m2 ＞BMI≥24 kg/m2),30例肥胖者(BMI≥28 kg/m2)及30例正常人.应用超声心动图及应变/应变率技术测量左心房5个壁10个节段左房应变(S)、左室收缩期左房应变率峰值(SSR)、左室舒张早期左房应变率峰值(ESR)及左室舒张晚期左房应变率峰值(ASR),并计算出平均值进行比较.结果 与正常组相比,超重组平均SSR及平均ESR减低,肥胖组平均S、平均SSR及平均ESR降低,超重组平均ASR降低;肥胖组平均ESR较超重组降低.结论 超重者左房储存器、管道及助力泵功能均受损,肥胖者左房储存器及管道功能受损更为明显,而助力泵功能未见明显受损.左房的三个功能相互调节来维持左室充盈.应变及应变率技术可用来评价超重及肥胖者左房功能改变.%Objective To investigate the impact of overweight and obesity on left atrial (LA) function in healthy subjects with excess body weight.Methods Conventional echocardiography and tissue Doppler imaging were performed in 30 obese subjects (BMI≥28 kg/m2),30 overweight subjects (BMI,24to 28 kg/m2) and 30 age-matched normal subjects (BMI＜24kg/m2).Strain (S),peak systolic strain rate (SSR),peak early diastolic strain rate (ESR) and peak late diastolic strain rate (ASR) values were used to evaluating LA function.Results Compared with controls,mean S,SSR and ESR were decreased in obese subjects,while mean SSR,ESR and ASR were decreased in overweight subjects.Compared with overweight subjects,mean ESR was decreased in obese subjects.Conclusions An impaired LA function is found in overweight and obese subjects who has no other clinically appreciable cause of heart disease by using strain and SR imaging.
Kamel, Hooman; Okin, Peter M.; Longstreth, W. T.; Elkind, Mitchell S.V.; Soliman, Elsayed Z.
Atrial fibrillation (AF) has long been associated with a heightened risk of ischemic stroke and systemic thromboembolism, but recent data require a re-evaluation of our understanding of the nature of this relationship. New findings about the temporal connection between AF and stroke, alongside evidence linking markers of left atrial abnormalities with stroke in the absence of apparent AF, suggest that left atrial thromboembolism may occur even without AF. These observations undermine the hypothesis that the dysrhythmia that defines AF is necessary and sufficient to cause thromboembolism. In this commentary, we instead suggest that the substrate for thromboembolism may often be the anatomic and physiological atrial derangements associated with AF. Therefore, our understanding of cardioembolic stroke may be more complete if we shift our representation of its origin from AF to the concept of atrial cardiopathy. PMID:26021638
William G. Stevenson, M.D
Full Text Available Atrial fibrillation is common in heart failure patients and is associated with increased mortality. Pharmacologic trials have not shown any survival benefit for a rhythm control over a rate control strategy. It has been suggested that sinus rhythm is associated with a survival benefit, but that the risks of anti-arrhythmic drug treatment and poor efficacy offset the beneficial effect. Catheter ablation for atrial fibrillation can establish sinus rhythm without the risks of anti-arrhythmic drug therapy. Data from randomized trials demonstrating a survival benefit for patients undergoing an ablation procedure for atrial fibrillation are still lacking. Ablation of the AV junction and permanent pacing remain a treatment alternative in otherwise refractory cases. Placement of a biventricular system may prevent or reduce negative consequences of chronic right ventricular pacing. Current objectives and options for treatment of atrial fibrillation in heart failure patients are reviewed.
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Jens Seiler; Tedrow, Usha B.; Stevenson, William G
Atrial fibrillation is common in heart failure patients and is associated with increased mortality. Pharmacologic trials have not shown any survival benefit for a rhythm control over a rate control strategy. It has been suggested that sinus rhythm is associated with a survival benefit, but that the risks of anti-arrhythmic drug treatment and poor efficacy offset the beneficial effect. Catheter ablation for atrial fibrillation can establish sinus rhythm without the risks of a...
William G. Stevenson, M.D; Usha B. Tedrow, M.D; Jens Seiler, M.D
Atrial fibrillation is common in heart failure patients and is associated with increased mortality. Pharmacologic trials have not shown any survival benefit for a rhythm control over a rate control strategy. It has been suggested that sinus rhythm is associated with a survival benefit, but that the risks of anti-arrhythmic drug treatment and poor efficacy offset the beneficial effect. Catheter ablation for atrial fibrillation can establish sinus rhythm without the risks of anti-arrhythmic dru...
Ramlawi, Basel; Abu Saleh, Walid K.
The Cox-maze procedure for the restoration of normal sinus rhythm, initially developed by Dr. James Cox, underwent several iterations over the years. The main concept consists of creating a series of transmural lesions in the right and left atria that disrupt re-entrant circuits responsible for propagating the abnormal atrial fibrillation rhythm. The left atrial appendage is excluded as a component of the Maze procedure. For the first three iterations of the Cox- maze procedure, these lesions...
Chin, B.; Lip, G. Y.
OBJECTIVE: To review the evidence for antithrombotic therapy in patients with nonrheumatic atrial fibrillation. QUALITY OF EVIDENCE: Five primary prevention trials and one secondary prevention trial compare antithrombotic therapy with placebo or no treatment. Two trials also determine the efficacy and safety of acetylsalicylic acid. MAIN FINDINGS: Warfarin reduces the risk of stroke by 68%. The effect is consistent in all identifiable groups of patients with nonrheumatic atrial fibrillation, ...
Michael Katsnelson,; Sebastian Koch; Tatjana Rundek
Non-valvular atrial fibrillation is a common and from a neurological perspective the most significant cardiac arrhythmia with a growing world-wide incidence. It also carries a significant associated morbidity and mortality, with cardioembolic strokes arguably being the most disabling sequelae. This brief review will highlight the important studies and the latest treatment modalities available for stroke prevention in patients with non-valvular atrial fibrillation.
A 2-year-old boy with an incidental finding of massive cardiomegaly on a chest X-ray was diagnosed with a giant right atrial aneurysm upon further investigation with echocardiography. The patient underwent successful surgical reduction of the right atrium and closure of the patent foramen ovale to prevent thromboembolic complications and to lower the risk of atrial arrhythmias. The resected atrium had paper-thin walls and pathological features of interstitial fibrosis with endocardial thickening
GONG Yong-tai; LI Wei-min; LI Yue; YANG Shu-sen; SHENG Li; YANG Ning; SHAN Hong-bo; XUE Hong-jie; LIU Wei; YANG Bao-feng; DONG De-li; LI Bao-xin
Background We hypothesize that increased atrial oxidative stress and inflammation may play an important role in atrial nerve sprouting and heterogeneous sympathetic hyperinnervation during atrial fibrillation (AF). To test the hypothesis, we examined whether the antioxidant and anti-inflammatory treatment with probucol attenuates atrial autonomic remodeling in a canine model of AF produced by prolonged rapid right atrial pacing. Methods Twenty-one dogs were divided into a sham-operated group, a control group and a probucol group. Dogs in the control group and probucol group underwent right atrial pacing at 400 beats per minute for 6 weeks, and those in the probucol group received probucol 1 week before rapid atrial pacing until pacing stopped. After 6-week rapid atrial pacing, general properties including left atrial structure and function, atrial hemodynamics and the inducibility and duration of AF were measured in all the groups. Atrial oxidative stress markers and serum C-reactive protein (CRP) concentration were estimated. The degree of nerve sprouting and sympathetic innervation at the right atrial anterior wall (RAAW) and the left atrial anterior wall (LAAW) were quantified by immunohistochemistry, atdal norepinephrine contents were also detected. Atrial beta-nerve growth factor (beta-NGF) mRNA and protein expression at the RAAW and LAAW were assessed by real-time quantitative RT-PCR and Western blotting respectively. Results Atrial tachypacing induced significant nerve sprouting and heterogeneous sympathetic hyperinnervation, and the magnitude of nerve sprouting and hyperinnervation was higher in the RAAW than in the LAAW. Atrial beta-NGF mRNA and protein levels were significantly increased at the RAAW and LAAW, and the upregulation of beta-NGF expression was greater at the RAAW than at the LAAW in the control group. The beta-NGF protein level was positively correlated with the density of sympathetic nerves in all groups. Probucol decreased the increase of
张燕; 佟达; 宋魁彦
Stress-strain relationship of longitudinal compressed hydrothermal-microwave treated juvenile and mature northeast China ash wood and their chemical composition variation were analyzed.The stress-strain constitutive relation of longitudinal compressed wood were established.Results showed that at the beginning of compression,the curves followed the linear Hooke's Law.Meanwhile,the curves primarily fit the linear mechanics relation at the elastic-plastic region.The founded stress-strain constitutive relation showed that both juvenile and mature wood longitudinal compression could be expressed by an equation consisting of a constant term (proportional ultimate stress) and stress-strain linear relationship.The higher modulus of elasticity (MOE) and stress of juvenile wood was caused mainly by the difference of wood components between juvenile and mature ash wood at the same longitudinal compression rate.%通过对水热-微波联合处理的水曲柳幼龄材和成熟材顺纹压缩过程中应力-应变关系和木材化学组分变化的分析,建立木材顺纹压缩应力-应变本构关系.结果表明:在水曲柳顺纹压缩的初始阶段,应力-应变符合线性的弹性虎克定律；在弹塑性阶段,也基本符合线性的力学关系,建立的水曲柳幼龄材和成熟材顺纹压缩应力-应变本构关系由常数项(比例极限应力)和应力-应变线性关系表达式两部分构成；相同顺纹压缩率下幼龄材弹性模量和应力大于成熟材,主要受到木材化学组分差异的影响.
Primary tumors of the heart are rare, their estimated incidence ranging between 0.0017-0.19%, and among them cardiac myxomas are the most common (50%). Right atrial localization is uncommon, occurring only in 15-20% of cases. Their clinical presentation ranges from an asymptomatic status to the presence of constitutional symptoms or symptoms pointing to the presence of cardiac obstruction or pulmonary embolism. A case is presented of a 36-year-old male patient with a history of asthenia, palpitations and reduced functional capacity. Transthoracic echocardiography revealed a large mass in the right atrium which prolapsed into the right ventricle and obstructed the tricuspid valve. The patient underwent cardiopulmonary bypass surgery and the mass (9x9 cm) was removed without any complication. Histological examination confirmed the diagnosis of myxoma.
Global left ventricular longitudinal strain is closely associated with increased neurohormonal activation after acute myocardial infarction in patients with both reduced and preserved ejection fraction
Ersbøll, Mads; Valeur, Nana; Mogensen, Ulrik Madvig;
N-terminal pro brain natriuretic peptide (NT-proBNP) is released in response to increased myocardial wall stress and is associated with adverse outcome in acute myocardial infarction. However, little is known about the relationship between longitudinal deformation indices and NT-proBNP....
Estudo comparativo entre a miniesternotomia em "L" invertido e esternotomia longitudinal total na correção cirúrgica da comunicação interatrial Comparative study between inverted "L" mini-sternotomy and complete sternotomy for the surgical treatment of the atrial septal defect (ASD
Luiz Cláudio Nery Sampaio
Full Text Available OBJETIVO: Comparar os resultados obtidos entre duas vias de acesso cirúrgico em pacientes submetidos à correção cirúrgica de comunicação interatrial (CIA. MÉTODO: Foram distribuídos 20 pacientes, com média de idade de 24,1±14,2 anos, em dois grupos. No grupo A, 10 pacientes (80% do sexo feminino, com média de idade de 20,9 ± 12,0 anos foram submetidos à correção da CIA por meio de uma esternotomia longitudinal total. No grupo B, 10 pacientes (80% do sexo feminino, com média de idade de 27,4 ± 16,1 anos foram submetidos à correção da CIA através de miniesternotomia em "L" invertido. Foi considerado significativo p OBJECTIVE: To compare the results obtained from two distinct surgical approaches in patients undergoing surgical correction of an atrial septal defect (ASD. METHOD: The study series consisted of 20 patients, with a mean age of 24.1±14.2 years, distributed in two groups. In group A, 10 patients (80% female, with a mean age of 20.9±12.0 years underwent surgical correction of ASD through a complete sternotomy. In group B, 10 patients (80% female, with mean age of 27.4±16.1 years, were operated through an inverted "L" mini-sternotomy. A p-value < 0.05 was considered statistically significant. RESULTS: There was no statistical significance for demographics variables, duration of surgery, cardiopulmonary bypass time, clamping time, amount of cardioplegia administered, thoracic drainage, ICU stay, duration of mechanical ventilatory support, amount of blood and its components transfused, arrhythmia or pacemaker usage. There was statistical significance (p= 0.00001 between incision size performed by complete sternotomy (group A and inverted "L" mini-sternotomy (group B, with mean incision size of 15.7±0.8 e 6.8±0.6cm, respectively. There was a difference in the mean hospital stay between the groups but without statistical significance (7.5±1.6 days in group A and 6.4±1.3 days in group B, with a p-value = 0.12. There
... Who Is at Risk for Atrial Fibrillation? Explore Atrial Fibrillation What Is... Types Other Names Causes Who Is at Risk Signs & Symptoms Diagnosis Treatments Prevention Living With Clinical Trials Links Related Topics Arrhythmia ...
Ramlawi, Basel; Abu Saleh, Walid K
The Cox-maze procedure for the restoration of normal sinus rhythm, initially developed by Dr. James Cox, underwent several iterations over the years. The main concept consists of creating a series of transmural lesions in the right and left atria that disrupt re-entrant circuits responsible for propagating the abnormal atrial fibrillation rhythm. The left atrial appendage is excluded as a component of the Maze procedure. For the first three iterations of the Cox- maze procedure, these lesions were performed using a surgical cut-and-sew approach that ensured transmurality. The Cox-Maze IV is the most currently accepted iteration. It achieves the same lesion set of the Cox- maze III but uses alternative energy sources to create the transmural lesions, potentially in a minimally invasive approach on the beating heart. High-frequency ultrasound, microwave, and laser energy have all been used with varying success in the past. Today, bipolar radiofrequency heat or cryotherapy cooling are the most accepted sources for creating linear lesions with consistent safety and transmurality. The robust and reliable nature of these energy delivery methods has yielded a success rate reaching 90% freedom from atrial fibrillation at 12 months. Such approaches offer a significant long-term advantage over catheter-based ablation, especially in patients having longstanding, persistent atrial fibrillation with characteristics such as dilated left atrial dimensions, poor ejection fraction, and failed catheter ablation. Based on these improved results, there currently is significant interest in developing a hybrid ablation strategy that incorporates the superior transmural robust lesions of surgical ablation, the reliable stroke prevention potential of epicardial left atrial appendage exclusion, and sophisticated mapping and confirmatory catheter-based ablation technology. Such a minimally invasive hybrid strategy for ablation may lead to the development of multidisciplinary "Afib teams" to
Voogt, Willem Gijsbert de
In patients with an indication for anti bradycardia pacing, atrial fibrillation (AF) is a common arrhythmia (30-50%) even in the absence of atrial tachy arrhythmias before pacemaker implantation. Pace prevention and pace intervention for atrial tachy arrhythmias could be an interesting adjuvant trea
Arias, Miguel A; Alonso-Fernández, Alberto; García-Río, Francisco; Sánchez, Ana; López, Juana M; Pagola, Carlos
A high prevalence of obstructive sleep apnea has been demonstrated in patients with atrial fibrillation. Our comments want to emphasize the importance of identifying and treating a large proportion of patients with atrial fibrillation who have undiagnosed obstructive sleep apnea as an additional preventive strategy for atrial fibrillation patients. PMID:16309764
Mostafa, Ashraf; EL-Haddad, Mohamed A.; Shenoy, Maithili; Tuliani, Tushar
Atrial fibrillation occurs in 5-40% patients after coronary artery bypass graft surgery. Atrial fibrillation increases mortality and morbidity in the post-operative period. We sought to conduct a comprehensive review of literature focusing on pathophysiology, risk factors, prevention and treatment of post coronary artery bypass graft atrial fibrillation.
Full Text Available A 22 year-old man presented to the emergency unit with the complaint of difficulty in breathing. In the physical exam, dyspnea and orthopnea were found. In the electocardiographic exam (ECG atrial flutter rhythm was seen. The transthoracic echocardiographic exam revealed a large atrial mass that was originating from interatrial septum. During surgery, complete surgical removal of the right atrial mass was successfully performed under moderate hypothermia. Histological investigations revealed a mass of 15 x 3 cm in diameter and the pathological examination showed that the lesion is a myxoma. Twelve months after surgical excision, clinical and chocardiographicalfollow-up showed a satisfactory exercise tolerance, sinus rhythm in ECG exam, and cardiac functions within normal limits.
Laurent, Valérie; Fauchier, Laurent; Pierre, Bertrand; Grimard, Caroline; Babuty, Dominique
Although cavotricuspid isthmus radiofrequency catheter ablation is considered curative therapy for typical atrial flutter, many patients develop an atrial fibrillation after ablation. The purpose of our study was to determine the incidence and the predictive factors of post-ablation atrial fibrillation. One hundred and forty eight consecutive patients underwent cavotricuspid isthmus ablation for the treatment of typical atrial flutter between January 2004 and December 2005 in our electrophysiological department. Complete cavotricuspid isthmus block was successfully obtained in 96.6% of the patients. At the end of the electrophysiological study a sustained atrial fibrillation was inducible in 20 patients (13.5%). During an average follow-up of 21.3 +/- 8.2 months, atrial fibrillation occurred in 27% of the patients. Univariate analysis identified four parameters correlated with post-ablation atrial fibrillation among the 21 parameters tested: the young age of the patients, a prior history of atrial fibrillation, an inducible atrial fibrillation, and a paroxysmal atrial flutter. Only inducible atrial fibrillation and paroxysmal atrial flutter were independent factors linked to atrial fibrillation after ablation. In our study the incidence of atrial fibrillation after cavotricuspid isthmus radiofrequency catheter ablation is 152 per 1,000 patient-years, i.e. 25 times higher than the incidence of atrial fibrillation in the general population of the same age. Twenty five percent of the patients who had neither prior history of atrial fibrillation nor structural heart disease suffered from atrial fibrillation during a mean follow-up of 21.3 +/- 8.2 months. All these results suggest that atrial flutter and fibrillation could be manifestations of a more general electrophysiologic disease. They emphasize the need for all these patients to benefit from regular, long-term cardiological follow-up after cavotricuspid isthmus ablation because of the high incidence of atrial
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.
Ramos, G. L.; Seplow, S.
Temperature controlled strain-gaged extensometer measures longitudinal and girth deflections of pressure vessels in excess of one percent strain during pressurization and depressurization with cryogenic fluids at cryogenic temperatures. The device is of beryllium-copper strips.
Full Text Available Atrial fibrillation is the most prevalent permanent arrhythmia. It may be associated with other cardiac pathologies which need surgical treatment. Various types of surgery including the traditional cut-sew operations and operations using different energy sources are currently in use. In comparison with medical treatment, surgery is safe, effective, and has reliable results.
Full Text Available Atrial fibrillation is common in heart failure patients and is associated with increased mortality. Pharmacologic trials have not shown any survival benefit for a rhythm control over a rate control strategy. It has been suggested that sinus rhythm is associated with a survival benefit, but that the risks of anti-arrhythmic drug treatment and poor efficacy offset the beneficial effect. Catheter ablation for atrial fibrillation can establish sinus rhythm without the risks of anti-arrhythmic drug therapy. Data from randomized trials demonstrating a survival benefit for patients undergoing an ablation procedure for atrial fibrillation are still lacking. Ablation of the AV junction and permanent pacing remain a treatment alternative in otherwise refractory cases. Placement of a biventricular system may prevent or reduce negative consequences of chronic right ventricular pacing. Current objectives and options for treatment of atrial fibrillation in heart failure patients are reviewed.
Kirchhof, Paulus; Breithardt, Günter; Aliot, Etienne;
The management of atrial fibrillation (AF) has seen marked changes in past years, with the introduction of new oral anticoagulants, new antiarrhythmic drugs, and the emergence of catheter ablation as a common intervention for rhythm control. Furthermore, new technologies enhance our ability to de...
Healey, Jeff S.; Connolly, Stuart J.; Gold, Michael R.; Israel, Carsten W.; Van Gelder, Isabelle C.; Capucci, Alessandro; Lau, C. P.; Fain, Eric; Yang, Sean; Bailleul, Christophe; Morillo, Carlos A.; Carlson, Mark; Themeles, Ellison; Kaufman, Elizabeth S.; Hohnloser, Stefan H.
BACKGROUND One quarter of strokes are of unknown cause, and subclinical atrial fibrillation may be a common etiologic factor. Pacemakers can detect subclinical episodes of rapid atrial rate, which correlate with electrocardiographically documented atrial fibrillation. We evaluated whether subclinica
... Twitter. What Are the Signs and Symptoms of Atrial Fibrillation? Atrial fibrillation (AF) usually causes the heart's lower ... Chest pain Dizziness or fainting Fatigue (tiredness) Confusion Atrial Fibrillation Complications AF has two major complications— stroke and ...
Auranen, Kari; Mehtälä, Juha; Tanskanen, Antti; S. Kaltoft, Margit
The state of pneumococcal carriage—that is, pneumococcal colonization in the nasopharynx of healthy persons—represents a reservoir for the spread of pneumococci among individuals. In light of the introduction of new pneumococcal conjugate vaccines, further knowledge on the dynamics of pneumococcal carriage is important. Different serotypes (strains) of pneumococcus are known to compete with each other in colonizing human hosts. Understanding the strength and mode of between-serotype competiti...
Camm, J; Ward, D.; Spurrell, R
Ten patients who suffered spontaneous paroxysms of atrial flutter were investigated by electrophysiological techniques. Two had overt Wolff-Parkinson-White syndrome; three Lown-Ganong-Levine syndrome; and one a concealed accessory atrioventricular connection. Atrial flutter was initiated, at study, by right atrial pacing and electrograms from the right atrium and coronary sinus were observed for at least five minutes to ensure stable flutter in both atria. Atrial flutter was terminated by 2.5...
Aim. Atrial fibrillation (AFib) is a major clinical issue and its occurrence is the main problem after catheter ablation of atrial flutter. The long-term occurrence of AFib after common atrial flutter ablation is still matter of debate as it may influence the therapeutic approach. So, the aim of our study was to analyze the determinants and the time course of AFib after radiofrequency catheter ablation of chronic common atrial flutter. Methods and Results. 89 consecutive patients (67.5 ± ...
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 st...
Kohári, Mária; Pap, Róbert
Atrial tachycardias are common after open heart surgery. Most commonly these are macro-reentrant including cavotricuspid isthmus dependent atrial flutter, incisional right atrial flutter and left atrial flutter. Focal atrial tachycardias occur less frequently. The specific type of atrial tachycardia highly depends on the type of surgical incision. Catheter ablation can be very effective, however requires a thorough understanding of anatomy and surgical technique.
Pallisgaard, Jannik L.; Schjerning, Anne-Marie; Lindhardt, Tommi B.;
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...
Murthy, Avinash M A; Jain, Ankit; Tan, Henry
A 1:1 conduction of atrial tachyarrhythmias, although not uncommon, usually is associated with the use of antiarrhythmic drugs; hyperthyroidism etc. Spontaneous 1:1 conduction of atrial flutter is indeed rare. We present a case of a spontaneous 1:1 conduction of a cavotricuspid isthmus-dependent atrial flutter.
Schoonderwoerd, BA; Ausma, J; Crijns, HJGM; Van Veldhuisen, DJ; Blaauw, EH; Van Gelder, IC
Atrial Ultrastructural Remodeling. Introduction: Atrial structural and electrophysiologic changes occur during atrial tachycardia. The role of high ventricular rate in these processes remains to be established. Methods and Results: Six goats were subjected to 4 weeks of rapid atrioventricular (AV) p
Patel, Taral K.; Yancy, Clyde W; Knight, Bradley P.
The public health burden of atrial fibrillation (AF) and associated thromboembolic stroke continues to grow at alarming rates. AF leads to a fivefold increase in the risk of stroke. Therefore, stroke prevention remains the most critical aspect of AF management. Current standard of care focuses on oral systemic anticoagulation, most commonly with warfarin and now with newer agents such as dabigatran, rivaroxaban, and apixaban. However, the challenges and limitations of oral anticoagulation hav...
Pozen, R G; Pastoriza, J; Rozanski, J J; Kessler, K M; Myerburg, R J
Eighteen male patients (mean age 59 years) who were electrically cardioverted for pure atrial flutter were retrospectively studied to determine those factors influencing the maintenance of regular sinus rhythm or reversion to atrial flutter. Six months after successful cardioversion, 10 patients (55%) had recurrent atrial flutter and eight patients (45%) were still in sinus rhythm. The two groups were not significantly different with respect to age, symptomatology, abnormalities on the 12 lea...
Voogt, Willem Gijsbert de
In patients with an indication for anti bradycardia pacing, atrial fibrillation (AF) is a common arrhythmia (30-50%) even in the absence of atrial tachy arrhythmias before pacemaker implantation. Pace prevention and pace intervention for atrial tachy arrhythmias could be an interesting adjuvant treatment in the prevention of the arrhythmia related complications. These treatment modalities when available in pacemaker systems could come at a relative low cost as the indication for pacemaker imp...
Jawad-Ul-Qamar, Muhammad; Kirchhof, Paulus
Atrial fibrillation continues to attract interest in the cardiovascular community and inHeart Over 60 original research and review papers published inHeartin 2014-2015 cover various aspects of atrial fibrillation, from associated conditions and precipitating factors to new approaches to management. Here, we provide an overview of articles on atrial fibrillation published inHeartin 2014-2015, highlighting new developments, emerging concepts and novel approaches to treatment. PMID:26791994
Chu, Michael W.A.; Yoshitsugu Nakamura; Bob Kiaii
Atrial fibrillation is the most common sustained arrhythmia and is associated with significant risks of thromboembolism, stroke, congestive heart failure, and death. There have been major advances in the management of atrial fibrillation including pharmacologic therapies, antithrombotic therapies, and ablation techniques. Surgery for atrial fibrillation, including both concomitant and stand-alone interventions, is an effective therapy to restore sinus rhythm. Minimally invasive surgical ablat...
Postoperative atrial fibrillation is the most common complication of cardiac surgery. It is associated with increased complication rates. Recent trials have suggested that inflammation and oxidative stress have key roles in the pathophysiology of atrial fibrillation. Current evidence evaluating the use of antiinflammatory and antioxidant agents, including statins, corticosteroids, N-acetylcysteine, vitamin C, and fish oil, to prevent postoperative atrial fibrillation is promising. However, la...
Lairikyengbam, S; Davies, A; Jones, P.
The aim of the study was to assess the extent to which published recommendations on the antithrombotic management of atrial fibrillation had been adopted into clinical practice in a busy district general hospital, and the impact of clinical audit on subsequent management. In the initial audit, 185 consecutive patients with atrial fibrillation were studied using their case notes to identify any further clinical risk factors for stroke. A management algorithm stratified patients with atrial fib...
... page: https://medlineplus.gov/news/fullstory_159459.html Aspirin Often Wrongly Prescribed for Atrial Fibrillation Blood thinners -- not aspirin -- dramatically cut the risk of stroke, researchers say ...
Lairikyengbam, S; Anderson, M.,; Davies, A
Atrial fibrillation is the commonest sustained cardiac arrhythmia. It accounts for >35% of all hospital admissions for cardiac arrhythmias in the United States. The presence of atrial fibrillation increases the mortality of a population by up to twofold. The risk of stroke increases from 1.5% in patients with atrial fibrillation from 50–59 years of age to up to 23.5% for such patients aged 80–89 years. Although the diagnosis of atrial fibrillation is usually straightforward, effective treatme...
Kirchhof, Paulus; Breithardt, Günter; Aliot, Etienne; Al Khatib, Sana; Apostolakis, Stavros; Auricchio, Angelo; Bailleul, Christophe; Bax, Jeroen; Benninger, Gerlinde; Blomstrom-Lundqvist, Carina; Boersma, Lucas; Boriani, Giuseppe; Brandes, Axel; Brown, Helen; Brueckmann, Martina; Calkins, Hugh; Casadei, Barbara; Clemens, Andreas; Crijns, Harry; Derwand, Roland; Dobrev, Dobromir; Ezekowitz, Michael; Fetsch, Thomas; Gerth, Andrea; Gillis, Anne; Gulizia, Michele; Hack, Guido; Haegeli, Laurent; Hatem, Stephane; Häusler, Karl Georg; Heidbüchel, Hein; Hernandez-Brichis, Jessica; Jais, Pierre; Kappenberger, Lukas; Kautzner, Joseph; Kim, Steven; Kuck, Karl-Heinz; Lane, Deirdre; Leute, Angelika; Lewalter, Thorsten; Meyer, Ralf; Mont, Lluis; Moses, Gregory; Mueller, Markus; Münzel, Felix; Näbauer, Michael; Nielsen, Jens Cosedis; Oeff, Michael; Oto, Ali; Pieske, Burkert; Pisters, Ron; Potpara, Tatjana; Rasmussen, Lars; Ravens, Ursula; Reiffel, James; Richard-Lordereau, Isabelle; Schäfer, Herbert; Schotten, Ulrich; Stegink, Wim; Stein, Kenneth; Steinbeck, Gerhard; Szumowski, Lukasz; Tavazzi, Luigi; Themistoclakis, Sakis; Thomitzek, Karen; Van Gelder, Isabelle C; von Stritzky, Berndt; Vincent, Alphons; Werring, David; Willems, Stephan; Lip, Gregory Y H; Camm, A John
The management of atrial fibrillation (AF) has seen marked changes in past years, with the introduction of new oral anticoagulants, new antiarrhythmic drugs, and the emergence of catheter ablation as a common intervention for rhythm control. Furthermore, new technologies enhance our ability to detect AF. Most clinical management decisions in AF patients can be based on validated parameters that encompass type of presentation, clinical factors, electrocardiogram analysis, and cardiac imaging. Despite these advances, patients with AF are still at increased risk for death, stroke, heart failure, 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, brain imaging, information on genetic predisposition, systemic or local inflammation, and markers for cardiac strain. Each of these promising avenues requires validation in the context of existing risk factors in patients. More importantly, a new taxonomy of AF may be needed based on the pathophysiological type of AF to allow personalized management of AF to come to full fruition. Continued translational research efforts are needed to personalize management of this prevalent disease in a better manner. All the efforts are expected to improve the management of patients with AF based on personalized therapy. PMID:23981824
Lappegård, K T; Hovland, A; Pop, G A M; Mollnes, T E
Atrial fibrillation is highly prevalent, and affected patients are at an increased risk of a number of complications, including heart failure and thrombo-embolism. Over the past years, there has been increasing interest in the role of inflammatory processes in atrial fibrillation, from the first occurrence of the arrhythmia to dreaded complications such as strokes or peripheral emboli. As the standard drug combination which aims at rate control and anticoagulation only offers partial protection against complications, newer agents are needed to optimize treatment. In this paper, we review recent knowledge regarding the impact of inflammation on the occurrence, recurrence, perpetuation and complications of the arrhythmia, as well as the role of anti-inflammatory therapies in the treatment for the disease. PMID:23672430
Chirag R. Barbhayia; Saurabh Kumar; Gregory F. Michaud
Atrial fibrillation requires a trigger that initiates the arrhythmia and substrate that favors perpetuation. Cardiac mapping is necessary to locate triggers and substrate so that an ablation strategy can be optimized. The most commonly used cardiac mapping approach is isochronal or activation mapping, which aims to create a spatial model of electrical wavefront propagation. Historically, activation mapping has been successful for mapping point source and single or double wave reentrant arr...
Robelia, Paul; Kopecky, Stephen; Thacher, Tom
Atrial fibrillation (AF) is an increasingly common cardiac arrhythmia. Many patients with new onset or recurrent AF present to the emergency department and are subsequently admitted to the hospital and seen by cardiology specialists for follow up. In an attempt to address this high utilization of acute health care resources, reduce costs, and improve patient care, our institution instituted a collaborative project between the departments of emergency medicine, cardiology, family medicine, and...
Roger Kerzner; Michael W. Rich
Atrial fibrillation (AF) is an extremely common condition in the elderly, with increasing prevalence around the world as the population ages. AF may be associated with serious health consequences, including stroke, heart failure, and decreased quality of life, so that careful management of AF by geriatric health care providers is required. With careful attention to anticoagulation therapy, and prudent use of medications and invasive procedures to minimize symptoms, many of the adverse health consequences of AF can be prevented.
Cardiac magnetic resonance imaging (MRI) is an important tool for the diagnosis of cardiac masses. Various cardiac tumors are predisposed to occurring in atrial structures. The aim of this review article is the description of atrial tumors and their morphological features in MRI. In general, cardiac tumors are rare: approximately 0.001-0.03% in autopsy studies. About 75% of them are benign. The most common cardiac tumor is the myxoma. They are predisposed to occur in the atria and show a characteristically strong hyperintense signal on T2-wieghted images in MRI. In other sequences a heterogeneous pattern reflects its variable histological appearance. Lipomas exhibit a signal behavior identical to fatty tissue with a typical passive movement in cine imaging. Fibroelastomas are the most common tumors of the cardiac valves. Consisting of avascular fibrous tissue, they often present with hypointense signal intensities. Thrombi attached to their surface can cause severe emboli even in small tumors. Amongst primary cardiac malignancies, sarcomas are most common and favor the atria. Secondary malignancies of the heart are far more common than primary ones (20-40 times). In case of known malignancies, approximately 10% of patients develop cardiac metastasis at the end of their disease. Lymphogenic metastases favor the pericardium, while hematogenic spread prefers the myocardium. Since they are not real atrial tumors, thrombi and anatomical structures of the atria have to be differentiated from other pathologies. (orig.)
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.
Effects of steroids and angiotensin converting enzyme inhibition on circumferential strain in boys with Duchenne muscular dystrophy: a cross-sectional and longitudinal study utilizing cardiovascular magnetic resonance
Kinnett Kathi J
Full Text Available Abstract Background Steroid use has prolonged ambulation in Duchenne muscular dystrophy (DMD and combined with advances in respiratory care overall management has improved such that cardiac manifestations have become the major cause of death. Unfortunately, there is no consensus for DMD-associated cardiac disease management. Our purpose was to assess effects of steroid use alone or in combination with angiotensin converting enzyme inhibitors (ACEI or angiotension receptor blocker (ARB on cardiovascular magnetic resonance (CMR derived circumferential strain (εcc. Methods We used CMR to assess effects of corticosteroids alone (Group A or in combination with ACEI or ARB (Group B on heart rate (HR, left ventricular ejection fraction (LVEF, mass (LVM, end diastolic volume (LVEDV and circumferential strain (εcc in a cohort of 171 DMD patients >5 years of age. Treatment decisions were made independently by physicians at both our institution and referral centers and not based on CMR results. Results Patients in Group A (114 studies were younger than those in Group B (92 studies(10 ± 2.4 vs. 12.4 ± 3.2 years, p cc magnitude was lower in Group B than Group A (-13.8 ± 1.9 vs. -12.8 ± 2.0, p = 0.0004, age correction using covariance analysis eliminated this effect. In a subset of patients who underwent serial CMR exams with an inter-study time of ~15 months, εcc worsened regardless of treatment group. Conclusions These results support the need for prospective clinical trials to identify more effective treatment regimens for DMD associated cardiac disease.
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
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
Kofidis, Theo; Lee, Chuen Neng
Minimally invasive cardiac operations require specialized equipment. Atrial retractors are a frequently used tool to expose heart valves for minimally invasive and open procedures. The models currently available in the market are efficient; however, they may be complex, bulky, or expensive. We introduce a novel, very simple atrial retractor we designed using ubiquitously available materials. PMID:21524488
Vaishnav, Aditi; Vaishnav, Avani; Lokhandwala, Yash
Atrial fibrillation is the most common sustained cardiac arrhythmia which is often troublesome to manage. Currently, rhythm and rate control medications are the mainstays of therapy. In 2 amiodarone-refractory highly symptomatic patients, an innovative approach using ranolazine, which selectively acts on Na+ channels and delays atrial depolarization, was tried successfully.
B. A. Tatarskii
Full Text Available Characteristics and classification of different patterns of paroxysmal atrial fibrillation are presented. Main indications to restoration of sinus rhythm are discussed. The features of main medications used to terminate of atrial fibrillation are given. The choice of antiarrhythmic drug is considerate. Necessity of individual approach to therapy tactics is proved.
Akdeniz, Celal; Tanidir, Ibrahim Cansaran; Tuzcu, Volkan
Blocked premature atrial contractions can cause bradycardia by resetting sinoatrial node and prolonging the RR intervals. Herein, we report the management of a patient with frequent premature atrial contractions in bigeminal pattern. The patient presented with symptomatic bradycardia and was successfully treated with propafenone. PMID:22469245
Conclusions: Persistent type of atrial fibrillation is an independent predictor of higher Galectin-3 concentration. This biomarker of fibrosis may be implied in the mechanisms of atrial remodeling and maintenance of atrial fibrillation, and thus be helpful for the design of therapeutic strategy in patients with atrial fibrillation.
Zhao, Zhiqiang; Chen, Yan; Li, Weimin; Wang, Xinghua; Li, Jian; Yang, Wansong; Cheng, Lijun; Liu, Tong; Liu, Enzhao; Li, Guangping
Atrial fibrillation (AF) contributing to the increasing mortality risk is the most common disease in clinical practice. Owing to the side effects and relative inefficacy of current antiarrhythmic drugs, some research focuses on renin-angiotensin-aldosterone system (RAS) for finding out the new treatment of AF. The purpose of this study is to confirm whether aliskiren as a proximal inhibitor of renin, which completely inhibits RAS, has beneficial effects on atrial structural remodeling in AF. In this study, rapid atrial pacing was induced at 500 beats per minute for 2 weeks in a canine model. A different dose of aliskiren was given orally for 2 weeks before rapid atrial pacing. HE staining and Masson's staining were used for analysis of myocardial fibrosis. TGF-β1, signal pathways, and pro-inflammatory cytokines were shown for the mechanism of structural remodeling after the treatment of aliskiren. Serious atrial fibrosis was induced by rapid atrial pacing, followed by the elevated TGF-β1, upregulated MEK and ERK1/2, and increased inflammatory factors. Aliskiren could apparently improve myocardial fibrosis by reducing the expression of TGF-β1, inhibiting MEK and ERK1/2 signal pathways, and decreasing IL-18 and TLR4 in both serum and atrial tissue. In conclusion, aliskiren could prevent atrial structural remodeling from rapid atrial pacing for 2 weeks. Aliskiren may play a potential beneficial role in the treatment of AF induced by rapid atrial pacing. PMID:27118660
Hui Zhu; Wei Zhang; Ming Zhong; Gong Zhang; Yun Zhang
Extracellular matrix (ECM) remodeling increases the vulnerability to atrial fibrillation (AF). Some gene expressions are crucial for the metabolism of ECM. The left atrium plays an important role in maintaining AF.However, most studies investigated only the right atrial tissue. We therefore chose human tissue samples from both the left and right atrial to detect the different gene expressions during structural remodeling in AF. The atrial appendages tissue samples from 24 patients with chronic AF and 12 patients with sinus rhythm were obtained when they were undergoing mitral/aortic valve replacement operation. The mRNA levels of matrix metalloproteinases-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1), disintegrin, metalloproteases-15, and integrins β1 were determined by reverse transcriptionpolymerase chain reaction (RT-PCR). in AF group, the level of MMP-9 in left atrial appendage (LAA) was increased (P＜0.001), while integrin β1 level was decreased (P＜ 0.05) compared with those expressed in right atrial appendage (RAA) tissue. The levels of disintegrin, metalloproteinases-15, and TIMP-1 genes in the LAA and RAA had no significant differences. The results demonstrated that the gene expressions in the LAA and RAA are different during AF, which implied that the mechanism of atrial structural remodeling in AF is due to multiple sources and is complicated.
Walsh, Philip; Kodoth, Vivek; McEneaney, David; Rodrigues, Paola; Velasquez, Jose; Waterman, Niall; Escalona, Omar
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 power transfer and sensing of ICI during cardioversion are evidenced as key to the advancement of low-energy atrial defibrillation. PMID:26404298
Khaykin, Yaariv; Shamiss, Yana
Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. It places an enormous burden on the patients, caregivers, and the society at large. While the main themes in the care of an AF patient have not changed over the years and continue to focus on stroke prevention, control of the ventricular, rate and rhythm maintenance, there have been a number of new developments in each of these realms. This paper will discuss the “hot” topics in AF in 2012 including new and upcoming med...
Kowey, P R; Marinchak, R A; Rials, S J; Filart, R A
Atrial fibrillation (AFib) is a common clinical entity, responsible for significant morbidity and mortality, but it also accounts for a large percentage of healthcare dollar expenditures. Efforts to treat this arrhythmia in the past have focused on subacute antithrombotic therapy and eventually use of antiarrhythmic drugs for maintenance of sinus rhythm. However, there has been a growing interest in the concept of acute electrical and pharmacologic conversion. This treatment strategy has a number of benefits, including immediate alleviation of patient symptoms, avoidance of antithrombotic therapy, and prevention of electrophysiologic remodeling, which is thought to contribute to the perpetuation of the arrhythmia. There is also increasing evidence that this is a cost-effective strategy in that it may obviate admission to the hospital and the cost of long-term therapy. This article represents a summary of the treatments that may be used acutely to control the ventricular response to AFib, prevent thromboembolic events, and provide for acute conversion either pharmacologically or electrically. It includes information on modalities that are currently available and those that are under active development. We anticipate that an active, acute treatment approach to AFib and atrial flutter will become the therapeutic norm in the next few years, especially as the benefits of these interventions are demonstrated in clinical trials. PMID:9525568
Pellman, Jason; Lyon, Robert C.; Sheikh, Farah
Atrial fibrosis has been strongly associated with the presence of heart diseases/arrhythmias, including congestive heart failure (CHF) and atrial fibrillation (AF). Inducibility of AF as a result of atrial fibrosis has been the subject of intense recent investigation, since it is the most commonly encountered arrhythmia in adults and can substantially increase the risk of premature death. Rhythm and rate control drugs as well as surgical interventions are used as therapies for AF; however, in...
Yingxue Dong; Shulong Zhang; Lianjun Gao; Hongwei Zhao; Donghui Yang; Yunlong Xia; Yanzong Yang
Objective Mechanisms of pulmonary vein isolation (PVI) for atrial fibrillation remain controversy.This study aimed to investigate the impact of PVI on vagal modulation to atria.Methods Eighteen adult mongrel dogs under general anesthesia were randomly divided into two groups.Bilateral cervical sympathovagal trunks were decentralized and sympathetic effects was blocked by metoprolol administration.Atrial electrical remodeling (AER) was established by rapid right atrial pacing at the rate of 600 bpm for 30 minutes.PVI was performed in group A.Atrial effective refractory period (ERP),vulnerability window (VW) of atrial fibrillation,and sinus rhythm cycle length (SCL) were measured at baseline and during vagal stimulation before and after atrial rapid pacing with and without PVI at fight atrial appendage (RAA),left atrial appendage (LAA),distal coronary sinus (CSd) and proximal coronary sinus (CSp).Results (1) Effects of PVI on vagal modulation:Shortening of SCL during vagal stimulation decreased significantly after PVI compared with that before PVI in group A (P＜0.001).Shortening of ERP during vagal stimulation decreaseed significantly after PVI compared with that before PVI (P＜0.05).VW of atrial fibrillation during vagal stimulation decreased significantly after PVI compared with that before PVI (P＜0.05).(2) Effects of PVI on AER:shortening of ERP before and after atrial rapid pacing increased significantly at baseline and vagal stimulation in group B compared with that in group A (P＜0.05).VW during vagal stimulation increased significantly after atrial rapid pacing in group B (P＜0.05).Conclusion PVI attenuates the vagal modulation to the atria,thereby decreases the susceptibility to atrial fibrillation mediated by vagal activity.PVI releases AER,which maybe contributes to the vagal denervation.Our study indicates that PVI not only can eradicate triggered foci but also modify substrates for AF.(J Geriatr Cardiol 2008;5:28-32)
Arbelo, Elena; Brugada, Josep; Hindricks, Gerhard;
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...... 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...
van Laar, Charlotte; Geuzebroek, Guillaume S C; Hofman, Frederik N; Van Putte, Bart P
The totally thoracoscopic left atrial maze (TT-maze) is a recent, minimally invasive surgical procedure for the treatment of atrial fibrillation, with promising results in terms of freedom from atrial fibrillation. The TT-maze consists of a bilateral, epicardial pulmonary vein isolation with the creation of a box using radiofrequency and exclusion of the left atrial appendage (LAA). In addition, the box is connected with the base of the LAA and furthermore with the mitral annulus with the so-called trigonum line. In this report, we describe our surgical approach and short-term results. PMID:26993056
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
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)
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Lipsett, Mark; Hamilton, Douglas; Lemery, Jay; Polk, James
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.
XUE Hong-jie; SHAN Hong-bo; LIU Jie; LI Wei-min; LI Yue; GONG Yong-tai; YANG Bao-feng; JIN Cheng-luo; SHENG Li; CHU Shan; ZHANG Li
Background Atrial fibrillation (AF) is accompanied by atrial structural remodeling. Calpain activity is induced during AR To lest a causal relationship between calpain activation and atrial structural changes, N-acetyl-Leu-Leu-Met (ALLM), a calpain inhibitor, was utilized in a canine AF model.Methods Fifteen dogs were randomly divided into 3 groups: sham-operated group, control group and calpain inhibitor group; each with 5 dogs. Sustained AF was induced by rapid right atrium pacing at 600 beats per minute for 3 weeks. ALLM was administered at a dosage of 1.0 mg-kg-1·d-1 in the calpain inhibitor group. Three weeks later, the proteolysis, protein expression of TnT and myosin, calpain l localization and expression and structural changes were examined in left atrial free walls, right atrial free walls and the interatrial septum respectively. Atrial size and contractile function were also measured by echocardiography.Results Long-term rapid atrial pacing induced marked structural changes such as enlarged atrial volume, myolysis, degradation of TnT and myosin, accumulation of glycogen and changes in mitochondrial shape and size, which were paralleled by an increase in calpain activity. The positive correlation between calpain activity and the degree of myolysis (rs=0.90 961, P＜0.0001) was demonstrated. In addition to structural abnormalities, pacing-induced atrial contractile dysfunction was observed in this study. The pacing-induced atrial structural alterations and loss of contractility were partially prevented by the calpain inhibitor ALLM.Conclusions Activation of calpain represents key features in the progression towards overt structural remodeling. Calpain inhibitor, ALLM, suppressed the increased calpain activity and reversed structural remodeling caused by sustained atrial fibrillation in the present model. Calpain Inhibition may therefore provide a possibility for therapeutic Intervention in AF.
Lubitz, Steven A.; Benjamin, Emelia J.; Ellinor, Patrick T.
Atrial fibrillation and congestive heart failure are morbid conditions that share common risk factors and frequently coexist. Each condition predisposes to the other, and the concomitant presence of the two identifies individuals at increased risk for mortality. Recent data have emerged which help elucidate the complex genetic and non-genetic pathophysiological mechanisms that contribute to the development of atrial fibrillation in individuals with congestive heart failure. Clinical trial res...
Pedersen, Ole Dyg; Brendorp, Bente; Køber, Lars;
Atrial fibrillation is the most commonly sustained cardiac arrhythmia and a common reason for mortality and morbidity. Atrial fibrillation causes disease for three reasons: i) the ventricular rate is often high, which leads to symptoms ranging from discomfort to life threatening heart failure; ii......) 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...... are in development, but to the author's knowledge only a single thrombin inhibitor is actively being developed for atrial fibrillation....
Vladimir Ernstovich Medvedev
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.
Zemlin, Christian W.; Mitrea, Bogdan G.; Pertsov, Arkady M.
Most commonly, atrial fibrillation is triggered by rapid bursts of electrical impulses originating in the myocardial sleeves of pulmonary veins (PVs). However, the nature of such bursts remains poorly understood. Here, we propose a mechanism of bursting consistent with the extensive empirical information about the electrophysiology of the PVs. The mechanism is essentially non-local and involves the spontaneous initiation of non-sustained spiral waves in the distal end of the muscle sleeves of the PVs. It reproduces the experimentally observed dynamics of the bursts, including their frequency, their intermittent character, and the unusual shape of the electrical signals in the pulmonary veins that are reminiscent of so-called early afterdepolarizations (EADs).
Renato Pietro Ricci; Taya V. Glotzer
Full Text Available The advent of cardiac implanted electronic devices with accurate atrial arrhythmia diagnostic capabilities has revealed a large burden of “silent “ atrial fibrillation that is present in the cardiac population. Many studies have been completed, and many more are ongoing, to determine the correct treatment course when these atrial arrhythmias are detected. Alongside the development of accurate atrial diagnostics within the devices, has been the growth an entire network of wireless home monitoring capability. It is now possible to see, over the internet, individual patients’ atrial arrhythmia burden on every day. This capability has tremendous promise for patient care, with the possibility of reducing strokes, decreasing heart failure, preventing cardiomyopathies, and likely substantially reducing health care costs. As this innovative diagnostic capability is generating large amounts of data, protocols for what should be done with the plethora of new information are being developed. In the pages that follow, we will present what is known about home monitoring for silent atrial fibrillation, and present the results of recent studies published in this arena.
Osmanagic, Armin; Möller, Sören; Osmanagic, Azra;
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 atrial...
Argenziano, Michael; Williams, Mathew R
Computer (robotic) enhancement has emerged as a facilitator of minimally invasive cardiac surgery and has been used to perform portions of intracardiac procedures via thoracotomy incisions. This report describes the use of the da Vinci surgical system in two totally endoscopic ("closed chest") cardiac operations: atrial septal defect closure and pulmonary vein isolation of atrial fibrillation. ASD closure: Fifteen patients underwent repair of a secundum-type atrial septal defect or patent foramen ovale by a totally endoscopic approach, utilizing the da Vinci robotic system. Cardiopulmonary bypass (CPB) was achieved peripherally. Cardioplegia was administered via the distal port of the arterial cannula after endoballoon inflation. Via three port incisions in the right chest, the entire operation including pericardiotomy; bicaval occlusion; atriotomy; atrial septopexy; and atrial closure was performed by a surgeon seated at a computer console. A fourth 15 mm port was utilized for suction and suture passage by a patient-side assistant. In one case, a recurrent shunt was identified and repaired on POD 5. Median ICU length of stay (LOS) was 20 hours, and median hospital LOS was 4 days. Atrial fibrillation surgery: This report also describes the pathway that we have pursued in the development of a totally endoscopic operation for atrial fibrillation. Beginning with animal models, we tested various ablative energy sources; methods of ablation; and minimally invasive approaches. This work has led to the development of a variety of minimally invasive surgical approaches including a totally endoscopic, robotically assisted beating heart procedure for the treatment of atrial fibrillation. PMID:12838483
Samir M. Said
Full Text Available Thromboembolic events are known complications of left atrial ablation therapy. We describe a complication which may also lead to systemic thromboembolism that has not been reported so far: the formation of a moving structure attached to the fossa ovalis after an attempted transseptal puncture in a 66-year old patient with symptomatic paroxysmal atrial fibrillation.
杨沙宁; 黄从新; 胡晓军; 金立军; 李凤翥; 彭水先
Objective To identify predictors of left atrial appendage stunning after the use of electrical cardioversion to restore sinus rhythm in patients with non-valvular atrial fibrillation.Methods A total of 68 consecutive patients (45 men, 23 women, 60.5±8.7 years of age) with non-valvular atrial fibrillation undergoing electrical cardioversion were enlisted in this study. Clinical and echocardiographic variables were analyzed by univariate regression and multivariate logistic regression to investigate the relationship between occurrences of left atrial appendage stunning and these factors. Results Univariate analysis revealed that, in comparing patients without and with left atrial appendage stunning, there were significant differences in the duration of atrial fibrillation > 8 weeks (32.3% vs 75.5%, P 50 mm (29.0% vs 54.1%, P 8 weeks (OR=7.249, 95%CI=1.998-26.304, P 50 mm (OR=3.896, 95%CI=1.105-13.734, P8 weeks, left atrial diameter >50 mm, left ventricular ejection fraction <50%, and cumulative energy of electrical cardioversion are independent predictors of left atrial appendage stunning. Anticoagulation treatment should be individualized for patients undergoing electrical cardioversion to reduce the risk of both cardioversion-related thromboembolic events and hemorrhagic complications caused by warfarin treatment.
Munkholm-Larsen, Stine; Cao, Christopher; Yan, Tristan D;
This review aims to evaluate systematically the safety and efficacy of percutaneous left atrial appendage occlusion (PLAAO) in stroke prevention for patients with atrial fibrillation (AF). A systematic review of peer-reviewed journals on PLAAO before June 2011 was performed on three electronic...
Alper, AT; Gungor, B; Turkkan, C; Tekkesin, AI
Premature atrial contraction is a common form of supraventricular arrhythmias. In rare cases, severe symptoms other than palpitation may occur. In this report, we present a patient with symptomatic bradycardia which developed secondary to blocked premature atrial contractions and was successfully treated with radiofrequency ablation.
Alper, At; Gungor, B; Turkkan, C; Tekkesin, Ai
Premature atrial contraction is a common form of supraventricular arrhythmias. In rare cases, severe symptoms other than palpitation may occur. In this report, we present a patient with symptomatic bradycardia which developed secondary to blocked premature atrial contractions and was successfully treated with radiofrequency ablation. PMID:23840105
Revishvili A. Sh.
Full Text Available This article describes a clinical case of a patient with left atrial myxoma combined with paroxysmal atrial fibrillation. General practitioner considered symptoms of left ventricular insufficiency (shortness of breath, cough, palpitation, dizziness, blood spitting as lung pathology. When paroxysms of atrial fibrillation became more frequent the patient was send to cardiologist. Transthoracic echocardiography revealed a tumor (55 × 52 mm arising from the middle third of interatrial septum, floating and partially obstructing left atrioventricular orifice. Patient underwent Maze IV procedure combined with tumor resection. Histological study of the tumor showed typical for heart myxoma structure and cells. This case shows on-time diagnostics and successful surgical treatment of the patient with left atrial myxoma combined with paroxysmal atrial fibrillation.
van Walraven, Carl; Hart, Robert G; Connolly, Stuart;
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...... 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...
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 (ff) 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 ff 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 f1, f2, and other peak frequencies as linear combinations thereof (mf1±nf2), 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
Clementy, Nicolas; Desprets, Laurent; Pierre, Bertrand; Lallemand, Bénédicte; Simeon, Edouard; Brunet-Bernard, Anne; Babuty, Dominique; Fauchier, Laurent
Similar predisposing factors are found in most types of atrial arrhythmias. The incidence of atrial fibrillation (AF) among patients with atrial flutter is high, suggesting similar outcomes in patients with those arrhythmias. We sought to investigate the long-term outcomes and prognostic factors of patients with AF and/or atrial flutter with contemporary management using radiofrequency ablation. In an academic institution, we retrospectively examined the clinical course of 8,962 consecutive patients admitted to our department with a diagnosis of AF and/or atrial flutter. After a median follow-up of 934 ± 1,134 days, 1,155 deaths and 715 stroke and/thromboembolic (TE) events were recorded. Patients with atrial flutter undergoing cavotricuspid isthmus ablation (n = 875, 37% with a history of AF) had a better survival rate than other patients (hazard ratio [HR] 0.35, 95% confidence interval [CI] 0.25 to 0.49, p <0.0001). Using Cox proportional hazards model and propensity score model, after adjustment for main other confounders, ablation for atrial flutter was significantly associated with a lower risk of all-cause mortality (HR 0.55, 95% CI 0.36 to 0.84, p = 0.006) and stroke and/or TE events (HR 0.53, 95% CI 0.30 to 0.92, p = 0.02). After ablation, there was no significant difference in the risk of TE between patients with a history of AF and those with atrial flutter alone (HR 0.83, 95% CI 0.41 to 1.67, p = 0.59). In conclusion, in patients with atrial tachyarrhythmias, those with atrial flutter with contemporary management who undergo cavotricuspid isthmus radiofrequency ablation independently have a lower risk of stroke and/or TE events and death of any cause, whether a history of AF is present or not. PMID:25200340
Lindhardsen, Jesper; Ahlehoff, Ole; Gislason, Gunnar Hilmar;
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....
Kirchhof, Paulus; Breithardt, Günter; Bax, Jeroen;
At least 30 million people worldwide carry a diagnosis of atrial fibrillation (AF), and many more suffer from undiagnosed, subclinical, or 'silent' AF. Atrial fibrillation-related cardiovascular mortality and morbidity, including cardiovascular deaths, heart failure, stroke, and hospitalizations,...
Jin, Qi; Pehrson, Steen; Jacobsen, Peter Karl;
BACKGROUND: Different atrial arrhythmias can coexist in the recipient and donor atria after heart transplantation. CASE PRESENTATION: We report an unusual case of a patient with three different types of atrial arrhythmia after heart transplantation: an atrial fibrillation in the recipient atria......, and a cavotricuspid isthmus dependent atrial flutter and a focal atrial tachycardia in the donor atria. 3D electroanatomical mapping and ablation were guided by remote magnetic navigation (RMN). Atrial fibrillation continued in the recipient atria even after the donor heart was converted to sinus...... rhythm by ablation. CONCLUSIONS: It is critical to understand the surgical anatomy of a bi-atrial anastomosis and its relevant electrical activation pattern before ablation. Appropriate electroanatomical mapping strategy with RMN can facilitate the successful ablation of post-transplant atrial...
... to Antithrombotic A Patient’s Guide to AntithromboticTherapy in Atrial Fibrillation AMERICAN COLLEGE OF CHEST PHYSICIANS Therapy in Atrial Fibrillation PATIENT EDUCATION GUIDE AMERICAN COLLEGE OF CHEST PHYSICIANS ...
... living with AFib Atrial Fibrillation • Introduction • What is Atrial Fibrillation? • Why AFib Matters • Understand your Risk for AFib Children • Symptoms of AFib • Treatment & Prevention of AFib Treatment Guidelines of AFib Treatment Options ...
Nicolas Clementy; Eric Piver; Nazih Benhenda; Anne Bernard; Bertrand Pierre; Edouard Siméon; Laurent Fauchier; Jean-Christophe Pagès; Dominique Babuty
Background: Mechanisms of maintenance of atrial fibrillation are known to include fibrosis. Galectin-3, as a biomarker of fibrosis, may be a valuable marker of atrial remodeling. We sought to find whether there was a link between clinical features and higher galectin-3 levels in patients with atrial fibrillation. Methods: Serum concentrations of Galectin-3 were determined in a consecutive series of patients addressed for ablation of atrial fibrillation. Results: One-hundred-and-eighty-s...
Mulder, Bart Antonius
Atrial fibrillation is the most common cardiac arrhythmia and the prevalence is expected to increase in the coming years. The same is true for heart failure. Atrial fibrillation may result in heart failure, and vice versa, but they can also exacerbate each other. The combination of atrial fibrillation and heart failure has important therapeutic implications to treat both diseases and create optimal outcomes for these patients. We started with patients with permanent atrial fibrillation. These...
Berg, van den, T.J.T.P.; Tuinenburg, A. E.; Crijns, H. J. G. M.; Gelder, De; Gosselink, A. T.; Lie, K. I.
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; ...
Ridge, Carole A
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.
Pawar, Ravindra S; Tiwari, Ashish; Suresh, P V; Raj, Vimal; Kaushik, Pradeepkumar
Giant right atrial aneurysm is a rare entity in infants and children. It needs to be distinguished from an atrial diverticulum, which can have similar presentation. Generally, an incidental finding in children, it can present with varied symptoms. We report a case of a giant right atrial aneurysm in an asymptomatic child with a large clot in the dilated right atrium, who underwent successful resection of the atrial aneurysm. PMID:26884450
Awerbach, Jordan D.; Khatib, Sammy; Moodie, Douglas S.; Snyder, Christopher S.
The fibrillin defect central to Marfan syndrome is believed to affect myocardial conduction and predispose affected patients to various arrhythmias, including ventricular tachycardia, atrial fibrillation, and atrioventricular nodal reentry tachycardia. Here we describe an adult Marfan patient with atrial ectopic tachycardia. To our knowledge, this is the first reported case of atrial ectopic tachycardia in the setting of Marfan syndrome.
Finet, J. Emanuel; Rosenbaum, David S.; Donahue, J. Kevin
Animal models of atrial fibrillation have taught us about mechanisms of this common disease. A variety of animal models exist, including models of lone atrial fibrillation and models of atrial fibrillation in the setting of heart failure, aging or pericardial inflammation. This chapter reviews these various models.
Theofilos M. Kolettis, MD
Full Text Available The association between clinical1 or subclinical2 hyperthyroidism and atrial fibrillation is established from large prospective cohort studies, with serum free thyroxin (T4 concentrations correlating with atrial fibrillation rates.3 However, the role of subclinical hypothyroidism as a causal factor for atrial fibrillation has not been elucidated.
T. N. Novikova
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...
Fauchier, Laurent; Taillandier, Sophie; Clementy, Nicolas
There is increasing recognition of the value of oral anticoagulation for stroke prevention in atrial fibrillation (AF), and the availability of new oral anticoagulants that overcome the limitations of vitamin K antagonists (VKA). Stroke risk assessment using the CHA2DS2-Vasc score allows identification of patients who are at truly low risk (score = 0) who should need no antithrombotic therapy, while all others (CHA2DS2-Vasc score > or = 1 with a risk of thromboembolic event > 1% per year) would be considered for oral anticoagulation. The HAS-BLED score has been recently proposed to easily assess bleeding risk in AF patients. A score of > or = 3 indicates "high risk" and some caution and regular review of the patient are needed. It also makes the clinician think of correctable common bleeding risk factors. The direct thrombin inhibitor dabigatran and factor Xa inhibitors rivaroxaban and apixaban are new oral anticoagulants that are at least as efficacious and safe as VKA in non valvular AF. Their advantages are easier use, predictable anticoagulant effects, low propensity for food and drug interactions, and lower rates of intracranial bleeding than with VKA, but they should not be used in patients with kidney disease at the present time. Overall, one may expect that more AF patients will be appropriately treated with oral anticoagulation in the next years. PMID:23513780
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...
Parikh, D N; J. Fisher; Moses, J W; Goldberg, H.L.; Levin, A. R.; Engle, M. A.; Borer, J S
A prominent "v" wave relative to the "a" wave in the jugular vein and right atrial pressure tracing is considered to be a common haemodynamic sign of atrial septal defect. Since the prevalence, age relation, and haemodynamic determinants of the "v" greater than or equal to "a" wave configuration have not been studied the pressure recordings from 15 adults and 80 children with an isolated secundum atrial septal defect in sinus rhythm and from 40 adults and 55 children in sinus rhythm without s...
连耀植; 李玉光; 张汉灵; 张元春; 闫纯英; 林建才; 许端敏; 张钰; 郑宝群; 麦芒
@@ Atrial fibrillation (AF) is a kind of common arrhythmia, which, besides affecting cardiac function, has another serious outcome, that is, it is easy to form atrial thrombosis and induce thrombus/embolus, especially cerebral embolus.The incidence of left atrial thrombosis (LAT)could reach 25%-30%(1), the incidence of embolic complication per year could reach 2. 98%-6.30%, even 20% or more(2,3). To prevent thrombosis so as to lower the incidence of cerebral stroke and other embolic complications has been so far the focal point of AF treatment.
Adeniran, Ismail; Maclver, David H.; Garratt, Clifford J.; Ye, Jianqiao; Hancox, Jules C.; Zhang, Henggui
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...
Full Text Available Oxidative stress has been implicated in the pathogenesis of atrial fibrillation. There are multiple systems in the myocardium which contribute to redox homeostasis, and loss of homeostasis can result in oxidative stress. Potential sources of oxidants include nitric oxide synthases, which normally produce nitric oxide in the heart. Two nitric oxide synthase isoforms (1 and 3 are normally expressed in the heart. During pathologies such as heart failure, there is induction of nitric oxide synthase 2 in multiple cell types in the myocardium. In certain conditions, the NOS enzymes may become uncoupled, shifting from production of nitric oxide to superoxide anion, a potent free radical and oxidant. Multiple lines of evidence suggest a role for nitric oxide synthases in the pathogenesis of atrial fibrillation. Therapeutic approaches to reduce atrial fibrillation by modulation of nitric oxide synthase activity may be beneficial, although further investigation of this strategy is needed.
Tolstrup, Janne Schurmann; Wium-Andersen, Marie Kim; Ørsted, David Dynnes;
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...
HUANG Cong-xin; CAO Feng; JIANG Hong; WANG Teng; LI Xia
@@ Atrial fibrillation (AF) is the most common sustained arrhythmia encountered in clinical practice.1 Its incidence increases with age and the presence of structural heart disease. It is a major cause of stroke, especially in the elderly. It has been shown that angiotensin converting enzyme inhibitor (ACEI) can reduce the incidence of AF after acute myocardial infarction.2 Several studies have shown that activation of the rennin-angiotensin system is associated with the mechanisms of AF. Irbesartan is a long-acting angiotensin Ⅱ type 1 receptor antagonist used widely in the treatment of hypertension.3 In recent years, it has been demonstrated that patients treated with amiodarone plus irbesartan had a lower rate of recurrence of atrial fibrillation than did patients treated with amiodarone alone.4 These findings suggest that the inhibition of angiotensin Ⅱ may prevent AF, but its underlying electrophysiological mechanisms are obscure. The purpose of this study is to investigate the effects of irbesartan on atrial cell electrophysiology.
Adrian Baranchuk; Diego Conde
Full Text Available To the Editor: We read with interest the article from Bitter et al. (1 published in the last volume of JAFIB. This non-systematic review covers some of the most important physiopathological aspects of the link between sleep disordered breathing (SDB and atrial fibrillation (AFib. We do agree with the authors on the role of hypertension, endothelial dysfunction and inflammation. These topics were, to our understanding and perspective, very well covered by the authors on this review. However, despite that the authors mentioned atrial remodeling a couple of times during their review, we are not sure that this topic and specifically atrial electrical remodeling, was properly discussed and referenced. The pathophysiology linking SDB to AF is multifactorial and may involve repetitive hypoxemia, increased sympathetic drive, fluctuations in intrathoracic pressure and systemic inflammation (2. These physiologic changes may induce structural and electrical remodeling serving as a substrate to the development of AFib. An indirect marker for such electrical remodeling is the prolongation of atrial conduction time, represented by increased maximum P-wave duration in the surface ECG. In a prior study, we showed that an increased P-wave duration has been associated with SDB (3. Interatrial block (IAB, defined as a surface P-wave duration > 120 ms, was more prevalent in patients with moderate-severe SDB (34.7% SDB vs. 0% controls, p 25 were independent predictors of maximum P-wave duration (p=0.001 and p<0.001 respectively (3. Another non-invasive method to determine atrial electrical remodeling is the Signal-averaged P-wave (SAPW duration. The SAPW duration represents the average of all P-wave durations in a given number of consecutive heartbeats. We recently postulated that SAPW would be useful to identify atrial electrical remodeling in patients with severe SDB and that treatment with C-PAP for 4-6 weeks may induce reverse atrial electrical remodeling (4
Marott, Sarah C W; Nielsen, Sune F; Benn, Marianne;
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...
Deformações residuais longitudinais decorrentes de tensões de crescimento em eucaliptos e suas associações com outras propriedades Longitudinal residual strains resulted from growth stresses in eucalypts and their association with other properties
José Tarcísio Lima
ânicas da madeira fossem significativamente estimadas por modelos múltiplos.Growth stresses are a limiting factor in the use of fast growing eucalypts for the production of sawing logs. Further studies are needed for the qualification and mensuration of these stresses in eucalypts trees in Brazil. Thus, the main objective of this work was to evaluate the application of a new instrument, CIRAD-Forêt extensometer, in the measurement of the longitudinal residual strain (DRL in standing trees of five genetic materials of eucalypts, experimentally cultivated in Aracruz-Espirito Santo, and to correlate the magnitude of such strain with other wood properties and tree dimensions. The results obtained showed that: i the extensometer is a simple, rapid and reliable instrument to measure and identify trees with different levels of growth stresses; ii the DRL associated to the growth stresses measured with the extensometer were in average equal to 71 mm; iii no statistical differences were found in the DRLs measured in different cardinal orientations; iv the DRLs varied significantly with the genetic material according to the analyses of variance; v for clone 1, in which the DRLs were measured in two positions along the stem (1.3 m and 2.5 m, the values were similar; vi among various wood properties, only basic density was positive and significantly correlated with the DRLs when the five genetic materials were analysed together; vii except for the stability factor (DBH/total height of variety 5, the correlation between DRL and the tree growth dimensions were not significant when the genetic materials were analyzed separately, however, when the five genetic materials were analyzed together, only total height of the tree did not result in significant correlation with the DRLs; viii DRL addition to the tree growth dimensions allowed density and several wood mechanical properties to be significantly estimated by multiple models.
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.
Duraj, Iwona; Broncel, Marlena
Atrial fibrillation (AF) and obesity is a growing problem of public health both in Poland and in the whole world. AF risk factors may be summarized as elderliness, male sex, smoking, hypertension, diabetes, obesity, coronary heart disease, heart failure, valvular heart disease, cardiac surgery. Once obesity is an independent, potentially modifiable risk factor for AF. The connection between obesity and atrial fibrillation is very up-to-date because of incremental prevalence, almost epidemic of obesity in the whole world. The probability of AF among obese patients increases with concomitant obstructive sleep apnea. Regardless many researches it hasn't been assessed yet how obesity itself predisposes to AF. It could be an effect of change in the atrial anatomy, the rise of atrial pressure, mechanical stretch, interstitial atrial fibrosis and disruption of atrial electric integrity. A great role is ascribed to inflammation, especially proinflammatory cytokines increased by adipocites of left atrial epicardial adiposity. PMID:26891428
Laukkanen, Jari A; Zaccardi, Francesco; Karppi, Jouni; Ronkainen, Kimmo; Kurl, Sudhir
There is limited knowledge on the relationship between kidney function and incidence of atrial fibrillation. Thus, this prospective study was designed to evaluate whether various biomarkers of kidney function are associated to the risk of atrial fibrillation. The study population consisted of 1840 subjects (615 women and 1225 men) aged 61-82 years. Cystatin C- and creatinine-based estimation of glomerular filtration rate (eGFRcys and eGRFcreat , respectively) and urinary albumin/creatinine ratio (ACR) were assessed to investigate their relationship with the risk of atrial fibrillation. During a median follow-up of 3.7 years, a total of 159 incident atrial fibrillation cases occurred. After adjustment for potential confounders, the risk of atrial fibrillation was increased (hazard ratio 2.74, 95% confidence interval (CI) 1.56-4.81, P atrial fibrillation (hazard ratio 2.16, CI 1.35-2.82, P atrial fibrillation. PMID:26780558
Pallisgaard, Jannik Langtved; Lindhardt, Tommi Bo; Olesen, Jonas Bjerring;
The global burden of atrial fibrillation and diabetes mellitus (diabetes) is considerable, and prevalence rates are increasing. Diabetes is associated with an increased risk of developing atrial fibrillation; however, diabetes also influences the management and prognosis of atrial fibrillation. In...... the following article, the authors describe the association between diabetes and atrial fibrillation; specifically, the significance of diabetes on the risk of atrial fibrillation, ischemic stroke and bleeding complications associated with anticoagulation. In addition, the authors evaluate the risks...... and outcomes of heart failure and the success rates of both ablation and cardioversion in atrial fibrillation patients with diabetes. Finally, this article describes the association of HbA1c levels with the management and prognosis of atrial fibrillation patients....
Diness, Jonas Goldin; Skibsbye, Lasse; Jespersen, Thomas;
We have shown previously that inhibition of small conductance Ca(2+)-activated K(+) (SK) channels is antiarrhythmic in models of acutely induced atrial fibrillation (AF). These models, however, do not take into account that AF derives from a wide range of predisposing factors, the most prevalent...... being hypertension. In this study we assessed the effects of two different SK channel inhibitors, NS8593 and UCL1684, in aging, spontaneously hypertensive rats to examine their antiarrhythmic properties in a setting of hypertension-induced atrial remodeling. Male spontaneously hypertensive rats and the...... normotensive Wistar-Kyoto rat strain were divided in 2×3 groups of animals aged 3, 8, and 11 months, respectively. The animals were randomly assigned to treatment with NS8593, UCL1684, or vehicle, and open chest in vivo experiments including burst pacing-induced AF were performed. The aging spontaneously...
McManus, David D.; Shaikh, Amir Y; Abhishek, FNU; Vasan, Ramachandran S.
Heart failure (HF) and atrial fibrillation (AF) are two of the most common cardiovascular diseases encountered in clinical practice, and the prevalence of these diseases continues to grow world-wide with the aging of the global population.
Luciane Cruz Lopes
Full Text Available BACKGROUND: Patients with atrial fibrillation considering use of anticoagulants must balance stroke reduction against bleeding risk. Knowledge of bleeding risk without the use of anticoagulants may help inform this decision. PURPOSE: To determine the rate of major bleeding reported in observational studies of atrial fibrillation patients not receiving Vitamin K antagonists (VKA. DATA SOURCES: We searched MEDLINE, EMBASE and CINAHL to October 2011 and examined reference lists of eligible studies and related reviews. STUDY SELECTION: All longitudinal cohort studies that included over 100 adult patients with atrial fibrillation not receiving VKA. DATA EXTRACTION: Teams of two reviewers independently and in duplicate adjudicated eligibility, assessed risk of bias and abstracted study characteristics and outcomes. DATA SYNTHESIS: Twenty-one eligible studies included 96,448 patients. Major bleeding rates varied widely, from 0 to 4.69 events per 100 patient-years. The pooled estimate in 13 studies with 78839 patients was 1.59 with a 99% confidence interval of 1.10 to 2.3 and median 1.42 (interquartile range 0.62-2.70. Pooled estimates for fatal bleeding and non-fatal bleeding from 4 studies that reported these outcomes were, respectively, 0.40 (0.34 to 0.46 and 1.18 (0.30 to 4.56 per 100 patient-years. In 9 randomized controlled trials (RCTs the median rate of major bleeding in patients not receiving either anticoagulant or antiplatelet therapy was 0.6 (interquartile 0.2 to 0.90, and in 12 RCTs the median rate of major bleeding in patients receiving a single antiplatelet agent was 0.75 (interquartile 0.4 to 1.4. CONCLUSION: Results suggest that patients with atrial fibrillation not receiving VKA enrolled in observational studies represent a population on average at higher risk of bleeding.
Haugan, Ketil; Olsen, Kristine Boisen; Hartvig, Line;
OBJECTIVE: As atrial conduction slowing is important in the pathogenesis of atrial reentry arrhythmias, a drug that increases atrial conduction or prevents atrial conduction slowing could serve to prevent atrial reentry arrhythmias. In this study, we investigated whether the novel stable antiarrh...
Valderrábano, Miguel; Price, Matthew J
Prevention of thromboembolic complications in atrial fibrillation remains a tremendous clinical challenge. Knowledge that the left atrial appendage (LAA) is the most common anatomical origin of cardioembolic strokes1 has been the main motivation to develop clinical and procedural strategies to exclude the LAA from the circulation, either surgically or percutaneously. This review discusses the rationale behind these strategies, their relative merits, and future prospects for LAA exclusion strategies. PMID:26306126
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.
Deborah Wolbrette, Deborah
Deborah Wolbrette, Mario Gonzalez, Soraya Samii, Javier Banchs, Erica Penny-Peterson, Gerald NaccarelliPenn State Heart and Vascular Institute, Penn State Milton S Hershey Medical Center, Hershey, Pennsylvania, USAAbstract: Dronedarone, a new Class III antiarrhythmic agent, has now been approved by the US Food and Drug Administration for use in patients with atrial fibrillation or atrial flutter. Approval came in March 2009 due to the positive results of the ATHENA trial showing significant r...
Kim, Ha Eun; Jung, Jo Won; Shin, Yu Rim; Park, Han Ki; Park, Young Hwan; Shin, Hong Ju
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. PMID:27298800
Sebastiaan Velthuis; Swaans, Martin J.; Mager, Johannes J.; Rensing, Benno J. W. M.; Lucas V. A. Boersma; Post, Martijn C.
Atrial fibrillation (AF) is the most common cardiac arrhythmia, affecting millions of individuals worldwide, and a major risk factor for disabling cerebral embolic stroke. Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant inherited disorder, characterized by vascular abnormalities with high-bleeding tendency and therefore intolerance for oral anticoagulation. We report a case of percutaneous closure of the left atrial appendage, which might be a good alternative strategy in...
Valderrábano, Miguel; Price, Matthew J.
Prevention of thromboembolic complications in atrial fibrillation remains a tremendous clinical challenge. Knowledge that the left atrial appendage (LAA) is the most common anatomical origin of cardioembolic strokes1 has been the main motivation to develop clinical and procedural strategies to exclude the LAA from the circulation, either surgically or percutaneously. This review discusses the rationale behind these strategies, their relative merits, and future prospects for LAA exclusion stra...
T. N. Novikova
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.
Worthley Matthew I
Full Text Available Abstract Background Percutaneous closure of atrial septal defects (ASDs should potentially reduce right heart volumes by removing left-to-right shunting. Due to ventricular interdependence, this may be associated with impaired left ventricular filling and potentially function. Furthermore, atrial changes post-ASD closure have been poorly understood and may be important for understanding risk of atrial arrhythmia post-ASD closure. Cardiovascular magnetic resonance (CMR is an accurate and reproducible imaging modality for the assessment of cardiac function and volumes. We assessed cardiac volumes pre- and post-percutaneous ASD closure using CMR. Methods Consecutive patients (n = 23 underwent CMR pre- and 6 months post-ASD closure. Steady state free precession cine CMR was performed using contiguous slices in both short and long axis views through the ASD. Data was collected for assessment of left and right atrial, ventricular end diastolic volumes (EDV and end systolic volumes (ESV. Data is presented as mean ± SD, volumes as mL, and paired t-testing performed between groups. Statistical significance was taken as p Results There was a significant reduction in right ventricular volumes at 6 months post-ASD closure (RVEDV: 208.7 ± 76.7 vs. 140.6 ± 60.4 mL, p Conclusion ASD closure leads to normalisation of ventricular volumes and also a reduction in right atrial volume. Further follow-up is required to assess how this predicts outcomes such as risk of atrial arrhythmias after such procedures.
Begg, Gordon A; Holden, Arun V; Lip, Gregory Y H; Plein, Sven; Tayebjee, Muzahir H
Rhythm control of atrial fibrillation (AF) remains challenging, with modest long-term success rates. Atrial fibrosis has been associated with AF, but the clinical utility of assessment of this fibrosis has yet to be fully elucidated. In this paper we review the current state of understanding of the pathophysiology of atrial fibrosis in AF, and its impact upon the instigation and propagation of the arrhythmia. Fibrosis causes an increase in volume of dysfunctional extracellular matrix, and is associated with cellular alterations such as hypertrophy, apoptosis and membrane dysfunction within the atrial myocardium. In turn, these cause pathological alterations to atrial conduction, such as increased anisotropy, conduction block and re-entry, which can lead to AF. We review current methods of assessing atrial fibrosis and their impact upon the prediction of success of interventional rhythm control strategies such as ablation and cardioversion. We focus particularly on circulating biomarkers of fibrosis and scar formation; their role in the fibrotic process, and their value in the prediction of rhythm control success. We also review imaging and invasive electrocardiographic mapping techniques that may identify fibrosis, and again assess their potential predictive value. In this area there exist many unanswered questions, but further work will help to refine techniques to reliably identify and treat those patients who are most likely to benefit from rhythm control treatment strategies. PMID:27389440
Full Text Available Ignacio Cruz-Gonzalez,* Juan Carlos Rama-Merchan,* Javier Rodriguez-Collado, Javier Martin-Moreiras, Alejandro Diego-Nieto, Antonio Arribas-Jimenez, Pedro Luís SanchezDepartment of Cardiology, University Hospital of Cardiology and IBSAL, Salamanca, Spain *Ignacio Cruz-Gonzalez and Juan Carlos Rama-Merchan have contributed equally to this work and should be considered co-first authors Abstract: Atrial fibrillation (AF is the most common sustained arrhythmia in clinical practice. AF is associated with a 4–5-fold increased risk of stroke and systemic embolism. Oral anticoagulant is the first-line therapy for this purpose, but it has various limitations and is often contraindicated or underutilized. Autopsy and surgical data have suggested that 90% of atrial thrombi in nonvalvular AF patients originate from the left atrial appendage, leading to the development of percutaneous closure for thromboembolic prevention. This paper examines the current evidence on left atrial appendage closure devices for cardiovascular risk reduction in AF patients. Keywords: atrial fibrillation, left atrial appendage, stroke, oral anticoagulant, percutaneous closure, thromboembolic prevention
Xu, Ye; Cheng, Kuan; Zhu, Wenqing
Key Clinical Message A 53‐year‐old man presented with heart palpitations while swallowing. Electrophysiologic study (EPS) and immunohistochemical results of his esophageal leiomyoma suggested that swallowing‐induced atrial tachycardia is related with neural reflex. S100‐immunopositive nerve fibers are demonstrated sympathetic nerves which possibly explain the mechanism. Metoprolol tartrate tablets are effective in our patient.
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 principles resp
Hatem, Stéphane N; Sanders, Prashanthan
Atrial fibrillation (AF) is the most frequent cardiac arrhythmia in clinical practice. AF is often associated with profound functional and structural alterations of the atrial myocardium that compose its substrate. Recently, a relationship between the thickness of epicardial adipose tissue (EAT) and the incidence and severity of AF has been reported. Adipose tissue is a biologically active organ regulating the metabolism of neighbouring organs. It is also a major source of cytokines. In the heart, EAT is contiguous with the myocardium without fascia boundaries resulting in paracrine effects through the release of adipokines. Indeed, Activin A, which is produced in abundance by EAT during heart failure or diabetes, shows a marked fibrotic effect on the atrial myocardium. The infiltration of adipocytes into the atrial myocardium could also disorganize the depolarization wave front favouring micro re-entry circuits and local conduction block. Finally, EAT contains progenitor cells in abundance and therefore could be a source of myofibroblasts producing extracellular matrix. The study on the role played by adipose tissue in the pathogenesis of AF is just starting and is highly likely to uncover new biomarkers and therapeutic targets for AF. PMID:24648445
Vadmann, Henrik; Pedersen, Susanne S; Nielsen, Jens Cosedis;
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...