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Sample records for atrial systolic force

  1. Association Between the Left Atrial and Left Atrial Appendages Systole Strain Rate in Patients with Atrial Fibrillation

    PubMed Central

    Tan, Changming; OuYang, Minzhi; Kong, Demiao; Zhou, Xinmin

    2016-01-01

    Background The aim of this research was to explore the association between the left atrial (LA) and left atrial appendages (LAA) systole strain rate (SSR) in patients with atrial fibrillation (AF), and to provide evidence to aid in the assessment of disease progression. Material/Methods A total of 180 patients with AF were selected for the study (130 patients with paroxysmal AF (Par AF) and 50 patients with persistence AF (PerAF). In addition, 60 healthy individuals were selected as a control group. The total and side wall SSRs were calculated. Results The total SSR in the control group was higher than in the ParAF and PerAF groups (2.87±0.45 vs. 2.15±0.56 vs. 1.92±0.62 and 6.24±1.61 vs. 4.45±1.42 vs. 3.66±1.55). The total SSR of LAA was correlated with that of LA in the AF patient groups and the control group; the correlation coefficients were 0.720, 0.563, and 0.421. However, the ratio of total SSR of LAA to that of LA was not significant statistically different among the three groups (2.24±0.41 vs. 2.35±0.58 vs. 2.03±0.56). The posterior wall had the lowest SSRs in the control group and ParAF group. Conclusions The SSRs of AF patients were lower than that of healthy individuals, and the degree was associated with disease progression. The SSR was different in different side walls, and gradually shorten with disease progression. PMID:27988786

  2. [Atrial filling fraction predicts left ventricular systolic function after myocardial infarction: pre-discharge echocardiographic evaluation].

    PubMed

    Galderisi, M; Fakher, A; Petrocelli, A; Alfieri, A; Garofalo, M; de Divitiis, O

    1995-10-01

    Aim of the study was to examine the relation between Doppler-derived indices of left ventricular diastolic and systolic function early after myocardial infarction. Fifty-three patients (31 males, 22 females) recovering from acute myocardial infarction underwent predischarge Doppler echocardiographic examination. Patients with age > 70 years, previous myocardial infarction, more than mild mitral and aortic regurgitation, mitral and aortic stenosis were excluded. Twenty-two healthy subjects (13 males; 9 females) free of coronary risk factors were selected as the control group. Both end-diastolic and end-systolic volumes and ejection fraction were measured by two-dimensional echocardiography. Pulsed Doppler was used to evaluate mitral inflow and left ventricular outflow velocity patterns. The following indices were measured: peak velocity of early (E) and late (A) flows, ratio of E/A peak velocities, ratio of early to late time velocity integrals, atrial filling fraction (time velocity integral A / time velocity integral of flow during total diastole) and deceleration time of E wave for mitral inflow; peak and time-velocity integral for left ventricular outflow. Stroke volume and cardiac output were obtained by pulsed Doppler using the left ventricular outflow method. The two groups were comparable for age, with blood pressure (p < 0.05) and heart rate (p < 0.01) reduced in myocardial infarction patients. Both end-diastolic and end-systolic volumes were significantly higher (both p < 0.0001) and ejection fraction (p < 0.0001) lower after myocardial infarction. Also stroke volume and cardiac output (both p < 0.0001) were reduced in myocardial infarction patients. No significant difference in Doppler indices of diastolic function was observed between the two groups, except for shortened deceleration time (p < 0.0001) in myocardial infarction patients. Multilinear regression analyses were performed separately into the two groups to identify determinants of left

  3. Atrial systole enhances intraventricular filling flow propagation during increasing heart rate

    PubMed Central

    Santhanakrishnan, Arvind; Okafor, Ikechukwu; Kumar, Gautam; Yoganathan, Ajit P.

    2016-01-01

    Diastolic fluid dynamics in the left ventricle (LV) has been examined in multiple clinical studies for understanding cardiac function in healthy humans and developing diagnostic measures in disease conditions. The question of how intraventricular filling vortex flow pattern is affected by increasing heart rate (HR) is still unanswered. Previous studies on healthy subjects have shown a correlation between increasing HR and diminished E/A ratio of transmitral peak velocities during early filling (E-wave) to atrial systole (A-wave). We hypothesize that with increasing HR under constant E/A ratio, E-wave contribution to intraventricular vortex propagation is diminished. A physiologic in vitro flow phantom consisting of a LV physical model was used for this study. HR was varied across 70, 100 and 120 beats per minute (bpm) with E/A of 1.1–1.2. Intraventricular flow patterns were characterized using 2D particle image velocimetry measured across three parallel longitudinal (apical-basal) planes in the LV. A pair of counter-rotating vortices was observed during E-wave across all HRs. With increasing HR, diminished vortex propagation occurred during E-wave and atrial systole was found to amplify secondary vorticity production. The diastolic time point where peak vortex circulation occurred was delayed with increasing HR, with peak circulation for 120 bpm occurring as late as 90% into diastole near the end of A-wave. The role of atrial systole is elevated for higher HR due to the limited time available for filling. Our baseline findings and analysis approach can be applied to studies of clinical conditions where impaired exercise tolerance is observed. PMID:26895781

  4. Depression of systolic and diastolic myocardial reserve during atrial pacing tachycardia in patients with dilated cardiomyopathy.

    PubMed Central

    Feldman, M D; Alderman, J D; Aroesty, J M; Royal, H D; Ferguson, J J; Owen, R M; Grossman, W; McKay, R G

    1988-01-01

    Previous reports have shown that increases in heart rate may result in enhanced left ventricular (LV) systolic and diastolic performance. To assess whether this phenomenon occurs in the presence of depressed LV function, the effects of pacing on LV pressure and volume were compared in seven patients with dilated cardiomyopathy (LV ejection fraction 0.19 +/- 0.11) and six patients with no or minimal coronary artery disease (LV ejection fraction 0.69 +/- 0.11). Patients with normal LV function demonstrated significant increases in LV peak-positive dP/dt, LV end-systolic pressure-volume ratio, LV peak filling rate, and a progressive leftward and downward shift of their pressure-volume diagrams, compatible with increased contractility and distensibility in response to pacing tachycardia. There was no change in LV peak-negative dP/dt or tau. Patients with dilated cardiomyopathy, in contrast, demonstrated no increase in either LV peak-positive dP/dt or the end-systolic pressure-volume ratio, and absence of a progressive leftward shift of their pressure-volume diagrams. Moreover, cardiomyopathy patients demonstrated no increase in LV peak-negative dP/dt or LV peak filling rate and a blunted downward shift of the diastolic limb of their pressure-volume diagrams. Tau, as determined from a derivative method, became abbreviated although never reaching control values. We conclude that patients with dilated cardiomyopathy may demonstrate little or no significant enhancement in systolic and diastolic function during atrial pacing tachycardia, suggesting a depression of both inotropic and lusitropic reserve. PMID:3183060

  5. Recovery of atrial systolic function after pharmacological conversion of chronic atrial fibrillation to sinus rhythm: a Doppler echocardiographic study.

    PubMed Central

    Jović, A.; Troskot, R.

    1997-01-01

    OBJECTIVE: To evaluate the time course of the recovery of atrial mechanical function after pharmacological cardioversion of chronic atrial fibrillation to sinus rhythm. PATIENTS AND METHODS: 21 patients (12 male, 9 female, aged 37-77 years) with chronic atrial fibrillation (< 6 months) were followed up by serial transmitral pulsed Doppler echocardiography. Echocardiographic studies were performed within the first 24 hours and on day 8, 15, and 30 after cardioversion. RESULTS: There was a significant increase (mean (SD)) in the peak A-wave velocity (from 0.35 (0.10) on day 1 to 0.50 (1.73) on day 8, and thereafter a gradual increase to 0.61 (0.14) m/s on day 30). Similarly, integrated late atrial velocities increased from 4.50 (1.46) on day 1 to 5.61 (1.73) on day 8 and 5.97 (1.47) cm/s2 on day 30. The atrial contribution to total transmitral flow increased significantly from 26 (7)% immediately after conversion of atrial fibrillation to sinus rhythm to 34 (7)% on day 30, indicating the haemodynamic benefit of the restoration of sinus rhythm. Left atrial diameter decreased but not significantly, from 4.11 (0.37) to 3.98 (0.34) cm (P < 0.005). CONCLUSIONS: These results suggest that restoration of atrial mechanical function after pharmacological cardioversion in patients with chronic atrial fibrillation is slow and gradual, as it is after electrical DC restoration of sinus rhythm. This time course may have important implications for determining how long treatment with anticoagulants and antiarrhythmic agents needs to continue in individual patients. It will also influence the clinical assessment of the haemodynamic benefit of restoring sinus rhythm in patients with chronic atrial fibrillation. Images PMID:9038694

  6. Ratio of Systolic Blood Pressure to Right Atrial Pressure, a Novel Marker to Predict Morbidity and Mortality in Acute Systolic Heart Failure.

    PubMed

    Omar, Hesham R; Charnigo, Richard; Guglin, Maya

    2017-04-01

    Congestion is the main contributor to heart failure (HF) morbidity and mortality. We assessed the combined role of congestion and decreased forward flow in predicting morbidity and mortality in acute systolic HF. The Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness trial data set was used to determine if the ratio of simultaneously measured systolic blood pressure (SBP)/right atrial pressure (RAP) on admission predicted HF rehospitalization and 6-month mortality. One hundred ninety-five patients (mean age 56.5 years, 75% men) who received pulmonary artery catheterization were studied. The RAP, SBP, and SBP/RAP had an area under the curve (AUC) of 0.593 (p = 0.0205), 0.585 (p = 0.0359), and 0.621 (p = 0.0026), respectively, in predicting HF rehospitalization. The SBP/RAP was a superior marker of HF rehospitalization compared with RAP alone (difference in AUC 0.0289, p = 0.0385). The optimal criterion of SBP/RAP <11 provided the highest combined sensitivity (77.1%) and specificity (50.9%) in predicting HF rehospitalization. The SBP/RAP had an AUC 0.622, p = 0.0108, and a cut-off value of SBP/RAP <8 had a sensitivity of 61.9% and specificity 64.1% in predicting mortality. Multivariate analysis showed that an SBP/RAP <11 independently predicted rehospitalization for HF (estimated odds ratio 3.318, 95% confidence interval 1.692 to 6.506, p = 0.0005) and an SBP/RAP <8 independently predicted mortality (estimated hazard ratio 2.025, 95% confidence interval 1.069 to 3.833, p = 0.030). In conclusion, SBP/RAP ratio is a marker that identifies a spectrum of complications after hospitalization of patients with decompensated systolic HF, starting with increased incidence of HF rehospitalization at SBP/RAP <11 to increased mortality with SBP/RAP <8.

  7. [Atrial fibrillation].

    PubMed

    Cárdenas, Manuel

    2007-01-01

    Atrial fibrillation is an arrhythmia characterized by no-coordinated atrial contraction that results in an inefficient atrial systole. The clinical classification of atrial fibrillation includes: ocassional, paroxysmal, persistent, and permanent. Multiple mechanisms have been described and accounts for a single ECG manifestation. Treatment should be individualized and has to considered several aspects including age, associated heart disease, and symptoms. Treatment strategies are: rhythm control, rate control, and thromboprophylaxis.

  8. Hemodynamic forces regulate developmental patterning of atrial conduction.

    PubMed

    Bressan, Michael C; Louie, Jonathan D; Mikawa, Takashi

    2014-01-01

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

  9. Efficacy and effects on cardiac function of radiofrequency catheter ablation vs. direct current cardioversion of persistent atrial fibrillation with left ventricular systolic dysfunction

    PubMed Central

    Wang, Maojing; Cai, Shanglang; Ding, Wei; Deng, Yujie; Zhao, Qing

    2017-01-01

    Objective To evaluate the effect of catheter ablation vs. direct current synchronized cardioversion (DCC) in patients with persistent atrial fibrillation (AF) and left ventricular systolic dysfunction, and to define baseline features of patients that will get more benefit from ablation. Methods From July 2013 to October 2014, 97 consecutive single-center patients with persistent AF and symptomatic heart failure (left ventricular ejection fraction (LVEF) <50%) underwent DCC followed by amiodarone (n = 40) or circumferential pulmonary vein isolation (PVI; n = 57) according to patient’s preference were recruited in the study. Post-ablation recurrence was treated with atrial roof and mitral isthmus lines ablation with or without PVI based on restoration or not of pulmonary vein (PV) potential conduction. Study outcomes were 12-month rate of sustained sinus rhythm (SR) and cardiac function. Baseline characteristics were compared between patients with and without cardiac function improvement post ablation. Results With similarly distributed characteristics at baseline, ablation (mean 1.8 procedures) relative to DCC yielded significantly higher level of 12-month SR maintenance rate (68.42% vs. 35%, P = 0.001); and better LVEF and New York Heart Association class. with significant effect for DCC only in maintained SR cases. Post ablation LVEF increased (>20% or to over 55%) in 31 (54.39%) patients with worse baseline cardiac function and ventricular rate control. Conclusions Catheter ablation relative to cardioversion of persistent AF with symptomatic heart failure yielded better 12-month SR maintenance and cardiac function. Compared with non-responders, patients with improved LVEF post-ablation had poorer ventricular rate control and cardiac function at baseline, suggesting a significant component of tachycardia-induced cardiomyopathy in this group. PMID:28350861

  10. Atrial fibrillation and heart failure: is atrial fibrillation a disease?

    PubMed

    Tilman, V

    2014-09-01

    Atrial fibrillation in heart failure often occur together. The relationship between atrial fibrillation and heart failure has remained a subject of research. The main manifestation of the violation of hydrodynamics in heart failure is the increased end-diastolic pressure, which is transmitted through the intercommunicated system (left ventricle-left atrium-pulmonary veins-alveolar capillaries) causing increased pulmonary wedge pressure with the danger for pulmonary edema. End-diastolic pressure is the sum of left ventricle diastolic pressure and left atrial systolic pressure. Stopping the mechanical systole of the left atrium can reduce the pressure in the system in heart failure. Atrial fibrillation stops the mechanical systole of the left atrium and decreases the intercommunicating pressure and pulmonary wedge pressure. It is possible that atrial fibrillation is a mechanism for protection from increasing end-diastolic pressure and pulmonary wedge pressure, and prevents the danger of pulmonary edema. This hypothesis may explain the relationship between heart failure and atrial fibrillation and their frequent association.

  11. Atrial Fibrillation

    MedlinePlus

    ... from the NHLBI on Twitter. What Is Atrial Fibrillation? Atrial fibrillation (A-tre-al fi-bri-LA- ... Works article. Understanding the Electrical Problem in Atrial Fibrillation In AF, the heart's electrical signals don't ...

  12. The impact of 6 weeks of atrial fibrillation on left atrial and ventricular structure and function

    PubMed Central

    Kazui, Toshinobu; Henn, Mathew C.; Watanabe, Yoshiyuki; Kovács, Sándor J.; Lawrance, Christopher P.; Greenberg, Jason W.; Moon, Marc; Schuessler, Richard B.; Damiano, Ralph J.

    2015-01-01

    Objective The impact of prolonged episodes of atrial fibrillation on atrial and ventricular function has been incompletely characterized. The purpose of this study was to investigate the influence of atrial fibrillation on left atrial and ventricular function in a rapid paced porcine model of atrial fibrillation. Methods A control group of pigs (group 1, n = 8) underwent left atrial and left ventricular conductance catheter studies and fibrosis analysis. A second group (group 2, n = 8) received a baseline cardiac magnetic resonance imaging to characterize left atrial and left ventricular function. The atria were rapidly paced into atrial fibrillation for 6 weeks followed by cardioversion and cardiac magnetic resonance imaging. Results After 6 weeks of atrial fibrillation, left atrial contractility defined by atrial end-systolic pressure-volume relationship slope was significantly lower in group 2 than in group 1 (1.1 ± 0.5 vs 1.7 ± 1.0; P = .041), whereas compliance from the end-diastolic pressure-volume relationship was unchanged (1.5 ± 0.9 vs 1.6 ± 1.3; P = .733). Compared with baseline, atrial fibrillation resulted in a significantly higher contribution of left atrial reservoir volume to stroke volume (32% vs 17%; P = .005) and lower left atrial booster pump volume contribution to stroke volume (19% vs 28%; P = .029). Atrial fibrillation also significantly increased maximum left atrial volume (206 ± 41 mL vs 90 ± 21 mL; P < .001). Left atrial fibrosis in group 2 was significantly higher than in group 1. Atrial fibrillation decreased left ventricular ejection fraction (29% ± 9% vs 58 ± 8%; P < .001), but left ventricular stroke volume was unchanged. Conclusions In a chronic model of atrial fibrillation, the left atrium demonstrated significant structural remodeling and decreased contractility. These data suggest that early intervention in patients with persistent atrial fibrillation might mitigate against adverse atrial and ventricular structural

  13. Atrial Fibrillation: Diagnosis

    MedlinePlus

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

  14. What is a Systolic Algorithm?

    NASA Astrophysics Data System (ADS)

    Rao, Sailesh K.; Kollath, T.

    1986-07-01

    In this paper, we show that every systolic array executes a Regular Iterative Algorithm with a strongly separating hyperplane and conversely, that every such algorithm can be implemented on a systolic array. This characterization provides us with an unified framework for describing the contributions of other authors. It also exposes the relevance of many fundamental concepts that were introduced in the sixties by Hennie, Waite and Karp, Miller and Winograd, to the present day concern of systolic array

  15. Atrial Fibrillation: Treatment

    MedlinePlus

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

  16. Atrial Fibrillation: Complications

    MedlinePlus

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

  17. A systolic array parallelizing compiler

    SciTech Connect

    Tseng, P.S. )

    1990-01-01

    This book presents a completely new approach to the problem of systolic array parallelizing compiler. It describes the AL parallelizing compiler for the Warp systolic array, the first working systolic array parallelizing compiler which can generate efficient parallel code for complete LINPACK routines. This book begins by analyzing the architectural strength of the Warp systolic array. It proposes a model for mapping programs onto the machine and introduces the notion of data relations for optimizing the program mapping. Also presented are successful applications of the AL compiler in matrix computation and image processing. A complete listing of the source program and compiler-generated parallel code are given to clarify the overall picture of the compiler. The book concludes that systolic array parallelizing compiler can produce efficient parallel code, almost identical to what the user would have written by hand.

  18. Atrial Fibrillation.

    PubMed

    Zimetbaum, Peter

    2017-03-07

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

  19. Atrial fibrillation

    PubMed Central

    Munger, Thomas M.; Wu, Li-Qun; Shen, Win K.

    2014-01-01

    Atrial fibrillation is the most common arrhythmia affecting patients today. Disease prevalence is increasing at an alarming rate worldwide, and is associated with often catastrophic and costly consequences, including heart failure, syncope, dementia, and stroke. Therapies including anticoagulants, anti-arrhythmic medications, devices, and non-pharmacologic procedures in the last 30 years have improved patients' functionality with the disease. Nonetheless, it remains imperative that further research into AF epidemiology, genetics, detection, and treatments continues to push forward rapidly as the worldwide population ages dramatically over the next 20 years. PMID:24474959

  20. Dynamically Reconfigurable Systolic Array Accelorators

    NASA Technical Reports Server (NTRS)

    Dasu, Aravind (Inventor); Barnes, Robert C. (Inventor)

    2014-01-01

    A polymorphic systolic array framework that works in conjunction with an embedded microprocessor on an FPGA, that allows for dynamic and complimentary scaling of acceleration levels of two algorithms active concurrently on the FPGA. Use is made of systolic arrays and hardware-software co-design to obtain an efficient multi-application acceleration system. The flexible and simple framework allows hosting of a broader range of algorithms and extendable to more complex applications in the area of aerospace embedded systems.

  1. Echocardiographic Parameters and Survival in Chagas Heart Disease with Severe Systolic Dysfunction

    PubMed Central

    Rassi, Daniela do Carmo; Vieira, Marcelo Luiz Campos; Arruda, Ana Lúcia Martins; Hotta, Viviane Tiemi; Furtado, Rogério Gomes; Rassi, Danilo Teixeira; Rassi, Salvador

    2014-01-01

    Background Echocardiography provides important information on the cardiac evaluation of patients with heart failure. The identification of echocardiographic parameters in severe Chagas heart disease would help implement treatment and assess prognosis. Objective To correlate echocardiographic parameters with the endpoint cardiovascular mortality in patients with ejection fraction < 35%. Methods Study with retrospective analysis of pre-specified echocardiographic parameters prospectively collected from 60 patients included in the Multicenter Randomized Trial of Cell Therapy in Patients with Heart Diseases (Estudo Multicêntrico Randomizado de Terapia Celular em Cardiopatias) - Chagas heart disease arm. The following parameters were collected: left ventricular systolic and diastolic diameters and volumes; ejection fraction; left atrial diameter; left atrial volume; indexed left atrial volume; systolic pulmonary artery pressure; integral of the aortic flow velocity; myocardial performance index; rate of increase of left ventricular pressure; isovolumic relaxation time; E, A, Em, Am and Sm wave velocities; E wave deceleration time; E/A and E/Em ratios; and mitral regurgitation. Results In the mean 24.18-month follow-up, 27 patients died. The mean ejection fraction was 26.6 ± 5.34%. In the multivariate analysis, the parameters ejection fraction (HR = 1.114; p = 0.3704), indexed left atrial volume (HR = 1.033; p < 0.0001) and E/Em ratio (HR = 0.95; p = 0.1261) were excluded. The indexed left atrial volume was an independent predictor in relation to the endpoint, and values > 70.71 mL/m2 were associated with a significant increase in mortality (log rank p < 0.0001). Conclusion The indexed left atrial volume was the only independent predictor of mortality in this population of Chagasic patients with severe systolic dysfunction. PMID:24553982

  2. Systoles in discrete dynamical systems

    NASA Astrophysics Data System (ADS)

    Fernandes, Sara; Grácio, Clara; Ramos, Carlos Correia

    2013-01-01

    The fruitful relationship between Geometry and Graph Theory has been explored by several authors benefiting also the Theory of discrete dynamical systems seen as Markov chains in graphs. In this work we will further explore the relation between these areas, giving a geometrical interpretation of notions from dynamical systems. In particular, we relate the topological entropy with the systole, here defined in the context of discrete dynamical systems. We show that for continuous interval maps the systole is trivial; however, for the class of interval maps with one discontinuity point the systole acquires relevance from the point of view of the dynamical behavior. Moreover, we define the geodesic length spectrum associated to a Markov interval map and we compute the referred spectrum in several examples.

  3. Dynamically Reconfigurable Systolic Array Accelerator

    NASA Technical Reports Server (NTRS)

    Dasu, Aravind; Barnes, Robert

    2012-01-01

    A polymorphic systolic array framework has been developed that works in conjunction with an embedded microprocessor on a field-programmable gate array (FPGA), which allows for dynamic and complimentary scaling of acceleration levels of two algorithms active concurrently on the FPGA. Use is made of systolic arrays and a hardware-software co-design to obtain an efficient multi-application acceleration system. The flexible and simple framework allows hosting of a broader range of algorithms, and is extendable to more complex applications in the area of aerospace embedded systems. FPGA chips can be responsive to realtime demands for changing applications needs, but only if the electronic fabric can respond fast enough. This systolic array framework allows for rapid partial and dynamic reconfiguration of the chip in response to the real-time needs of scalability, and adaptability of executables.

  4. What Is Atrial Fibrillation?

    MedlinePlus

    ANSWERS by heart Cardiovascular Conditions What Is Atrial Fibrillation? Your heart has a natural pacemaker, called the “ ... if the electric signals are normal. In atrial fibrillation (AFib), the heart’s two small upper chambers (atria) ...

  5. Management of atrial fibrillation.

    PubMed

    Moukabary, Talal; Gonzalez, Mario D

    2015-07-01

    Atrial fibrillation is a very common clinical problem with a high prevalence that is expected to rise over time because of increasing risk factors (eg, age, obesity, hypertension). This high prevalence is also associated with high cost, because atrial fibrillation represents about 1% of overall health care spending. The management of atrial fibrillation involves multiple facets: (1) management of underlying disease if present and the management of atrial fibrillation risk factors, (2) prevention of thromboembolism, (3) control of the ventricular rate during atrial fibrillation, and (4) restoration and maintenance of normal sinus rhythm.

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

    PubMed Central

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

    2017-01-01

    Background/Aims The aim of this study was to investigate atrial conduction times and left atrial mechanical functions, the noninvasive predictors of atrial fibrillation, in prediabetic patients with impaired fasting glucose (IFG) and impaired glucose tolerance (IGT). Methods Study included 59 patients (23 males, 36 females; mean age 52.5 ± 10.6 years) diagnosed with IFG or IGT by the American Diabetes Association criteria, and 43 healthy adults (22 males, 21 females; mean age 48.5 ± 12.1 years). Conventional and tissue Doppler echocardiography were performed. The electromechanical delay parameters were measured from the onset of the P wave on the surface electrocardiogram to the onset of the atrial systolic wave on tissue Doppler imaging from septum, lateral, and right ventricular annuli. The left atrial volumes were calculated by the disk method. Left atrial mechanical functions were calculated. Results The mitral E/A and E’/A’ ratios measured from the lateral and septal annuli were significantly lower in the prediabetics compared to the controls. The interatrial and left atrial electromechanical delay were significantly longer in prediabetic group compared to the controls. Left atrial active emptying volume (LAAEV) and fraction (LAAEF) were significantly higher in the prediabetics than the controls. LAAEV and LAAEF were significantly correlated with E/A, lateral and septal E’/A’. Conclusions In the prediabetic patients, the atrial conduction times and P wave dispersion on surface electrocardiographic were longer before the development of overt diabetes. In addition, the left atrial mechanical functions were impaired secondary to a deterioration in the diastolic functions in the prediabetic patients. PMID:27919159

  7. How Is Atrial Fibrillation Treated?

    MedlinePlus

    ... from the NHLBI on Twitter. How Is Atrial Fibrillation Treated? Treatment for atrial fibrillation (AF) depends on ... much thyroid hormone). Who Needs Treatment for Atrial Fibrillation? People who have AF but don't have ...

  8. Systolic VLSI for Kalman filters

    NASA Technical Reports Server (NTRS)

    Yeh, H.-G.; Chang, J. J.

    1986-01-01

    A novel two-dimensional parallel computing method for real-time Kalman filtering is presented. The mathematical formulation of a Kalman filter algorithm is rearranged to be the type of Faddeev algorithm for generalizing signal processing. The data flow mapping from the Faddeev algorithm to a two-dimensional concurrent computing structure is developed. The architecture of the resulting processor cells is regular, simple, expandable, and therefore naturally suitable for VLSI chip implementation. The computing methodology and the two-dimensional systolic arrays are useful for Kalman filter applications as well as other matrix/vector based algebraic computations.

  9. Organized Atrial Tachycardias after Atrial Fibrillation Ablation

    PubMed Central

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

    2011-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

  11. Atrial fibrillation - discharge

    MedlinePlus

    Auricular fibrillation - discharge; A-fib - discharge; AF - discharge; Afib - discharge ... been in the hospital because you have atrial fibrillation . This condition occurs when your heart beats faster ...

  12. Impact of atrial fibrillation on the accuracy of oscillometric blood pressure monitoring.

    PubMed

    Pagonas, Nikolaos; Schmidt, Sven; Eysel, Jörg; Compton, Friederike; Hoffmann, Clemens; Seibert, Felix; Hilpert, Justus; Tschöpe, Carsten; Zidek, Walter; Westhoff, Timm H

    2013-09-01

    The introduction of automated oscillometric blood pressure monitors was the basis for today's widespread use of blood pressure self-measurement. However, in atrial fibrillation, there is a controversial debate on the use of oscillometry because there is a high variability of heart rate and stroke volume. To date, the accuracy of oscillometric blood pressure monitoring in atrial fibrillation has only been investigated using auscultatory sphygmomanometry as reference method, which may be biased by arrhythmia as well. We performed a cross-sectional study in 102 patients (52 sinus rhythm, 50 atrial fibrillation) assessing the accuracy of an automated and validated oscillometric upper arm (M5 Professional, Omron) and wrist device (R5 Professional, Omron) to invasively assessed arterial pressure. Blood pressure values were calculated as the mean of 3 consecutive measurements. Systolic and diastolic blood pressure did not significantly differ in patients with sinus rhythm and atrial fibrillation, independent of the method of measurement (P>0.05 each). The within-subject variability of the oscillometric measurements was higher in patients with atrial fibrillation compared with sinus rhythm (P<0.01 each). The biases of systolic and diastolic blood pressure, however, did not significantly differ in presence or absence of atrial fibrillation in Bland-Altmann analysis (P>0.05 each). In conclusion, atrial fibrillation did not significantly affect the accuracy of oscillometric measurements, if 3 repeated measurements were performed.

  13. Practice implications of the Atrial Fibrillation Guidelines.

    PubMed

    Curtis, Anne B

    2013-06-01

    Atrial fibrillation is one of the most common and complex cardiac arrhythmias. Using currently available evidence, leading medical societies have established recommendations for the optimal management of atrial fibrillation. These guidelines have recently been updated by 4 consensus groups: the European Society of Cardiology, the American College of Chest Physicians, the Canadian Cardiovascular Society, and a task force of 3 societies from the United States: the American College of Cardiology Foundation, the American Heart Association, and the Heart Rhythm Society. The present review focused on the similarities and differences among these recently updated guidelines. Key revisions included updated information on newer treatments for rhythm control, treatment options to reduce atrial fibrillation complications, and updated anticoagulant management for thromboprophylaxis.

  14. Left Atrial Appendage Exclusion for Atrial Fibrillation

    PubMed Central

    Syed, Faisal F.; DeSimone, Christopher V.; Friedman, Paul A.; Asirvatham, Samuel J.

    2015-01-01

    SYNOPSIS Percutaneous left atrial appendage (LAA) closure is increasingly being used as a treatment strategy to prevent stroke in patients with atrial fibrillation (AF) who have contraindications to anticoagulants. A number of approaches and devices have been developed in the last few years, each with their own unique set of advantages and disadvantages. We review the published studies on surgical and percutaneous approaches to LAA closure; focusing on stroke mechanisms in AF, LAA structure and function relevant to stroke prevention, practical differences in procedural approach, and clinical considerations surrounding management. PMID:25443240

  15. Force.

    ERIC Educational Resources Information Center

    Gamble, Reed

    1989-01-01

    Discusses pupil misconceptions concerning forces. Summarizes some of Assessment of Performance Unit's findings on meaning of (1) force, (2) force and motion in one dimension and two dimensions, and (3) Newton's second law. (YP)

  16. Surgery for Atrial Fibrillation.

    PubMed

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

    2016-04-01

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

  17. Surgery for atrial fibrillation.

    PubMed

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

    2014-11-01

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

  18. Distinct contractile and molecular differences between two goat models of atrial dysfunction: AV block-induced atrial dilatation and atrial fibrillation.

    PubMed

    Greiser, Maura; Neuberger, Hans-Ruprecht; Harks, Erik; El-Armouche, Ali; Boknik, Peter; de Haan, Sunniva; Verheyen, Fons; Verheule, Sander; Schmitz, Wilhelm; Ravens, Ursula; Nattel, Stanley; Allessie, Maurits A; Dobrev, Dobromir; Schotten, Ulrich

    2009-03-01

    Atrial dilatation is an independent risk factor for thromboembolism in patients with and without atrial fibrillation (AF). In many patients, atrial dilatation goes along with depressed contractile function of the dilated atria. While some mechanisms causing atrial contractile dysfunction in fibrillating atria have been addressed previously, the cellular and molecular mechanisms of atrial contractile remodeling in dilated atria are unknown. This study characterized in vivo atrial contractile function in a goat model of atrial dilatation and compared it to a goat model of AF. Differences in the underlying mechanisms were elucidated by studying contractile function, electrophysiology and sarcoplasmic reticulum (SR) Ca2+ load in atrial muscle bundles and by analyzing expression and phosphorylation levels of key Ca2+-handling proteins, myofilaments and the expression and activity of their upstream regulators. In 7 chronically instrumented, awake goats atrial contractile dysfunction was monitored during 3 weeks of progressive atrial dilatation after AV-node ablation (AV block goats (AVB)). In open chest experiments atrial work index (AWI) and refractoriness were measured (10 goats with AVB, 5 goats with ten days of AF induced by repetitive atrial burst pacing (AF), 10 controls). Isometric force of contraction (FC), transmembrane action potentials (APs) and rapid cooling contractures (RCC, a measure of SR Ca2+ load) were studied in right atrial muscle bundles. Total and phosphorylated Ca2+-handling and myofilament protein levels were quantified by Western blot. In AVB goats, atrial size increased by 18% (from 26.6+/-4.4 to 31.6+/-5.5 mm, n=7 p<0.01) while atrial fractional shortening (AFS) decreased (from 18.4+/-1.7 to 12.8+/-4.0% at 400 ms, n=7, p<0.01). In open chest experiments, AWI was reduced in AVB and in AF goats compared to controls (at 400 ms: 8.4+/-0.9, n=7, and 3.2+/-1.8, n=5, vs 18.9+/-5.3 mmxmmHg, n=7, respectively, p<0.05 vs control). FC of isolated right

  19. Atrial Electrophysiological Remodeling and Fibrillation in Heart Failure

    PubMed Central

    Pandit, Sandeep V.; Workman, Antony J.

    2016-01-01

    Heart failure (HF) causes complex, chronic changes in atrial structure and function, which can cause substantial electrophysiological remodeling and predispose the individual to atrial fibrillation (AF). Pharmacological treatments for preventing AF in patients with HF are limited. Improved understanding of the atrial electrical and ionic/molecular mechanisms that promote AF in these patients could lead to the identification of novel therapeutic targets. Animal models of HF have identified numerous changes in atrial ion currents, intracellular calcium handling, action potential waveform and conduction, as well as expression and signaling of associated proteins. These studies have shown that the pattern of electrophysiological remodeling likely depends on the duration of HF, the underlying cardiac pathology, and the species studied. In atrial myocytes and tissues obtained from patients with HF or left ventricular systolic dysfunction, the data on changes in ion currents and action potentials are largely equivocal, probably owing mainly to difficulties in controlling for the confounding influences of multiple variables, such as patient’s age, sex, disease history, and drug treatments, as well as the technical challenges in obtaining such data. In this review, we provide a summary and comparison of the main animal and human electrophysiological studies to date, with the aim of highlighting the consistencies in some of the remodeling patterns, as well as identifying areas of contention and gaps in the knowledge, which warrant further investigation. PMID:27812293

  20. Direct Measurement of Left Atrial Pressure during Routine Transradial Catheterization

    PubMed Central

    Fa'ak, Faisal; Younis, George

    2016-01-01

    Left atrial pressure indicates the left ventricular filling pressure in patients who have systolic or diastolic left ventricular dysfunction or valvular heart disease. The use of indirect surrogate methods to determine left atrial pressure has been essential in the modern evaluation and treatment of cardiovascular disease because of the difficulty and inherent risks associated with direct methods (typically the transseptal approach). One method that has been widely used to determine left atrial pressure indirectly is Swan-Ganz catheterization, in which a balloon-flotation technique is applied to measure pulmonary capillary wedge pressure; however, this approach has been associated with several limitations and potential risks. Measuring left ventricular end-diastolic pressure has also been widely used as a simple means to estimate filling pressures but remains a surrogate for the gold standard of directly measuring left atrial pressure. We describe a simple, low-risk method to directly measure left atrial pressure that involves the use of standard coronary catheterization techniques during a transradial procedure. PMID:28100968

  1. Atrial septal defects in Florida panthers.

    PubMed

    Cunningham, M W; Dunbar, M R; Buergelt, C D; Homer, B L; Roelke-Parker, M E; Taylor, S K; King, R; Citino, S B; Glass, C

    1999-07-01

    ; a bubble contrast study indicated regurgitation across the tricuspid valve. Echocardiographic abnormalities in FP20 included right atrial and ventricular lilatation, atrial septal drop-out, and severe tricuspid regurgitation; non-selective angiography revealed significant left to right shunting across the ASD. All panthers with severe ASDs ausculted (n = 3) had systolic right or left-sided grade I-V/VI murmurs loudest at the heart base. All male panthers with ASDs (n = 3) (100%) and 9 of 17 (53%) male panthers without ASDs in this study were cryptorchid.

  2. Atrial Fibrillation Medications

    MedlinePlus

    ... think you are pregnant If you notice red, dark brown or black urine or stools If you ... Fibrillation • Introduction • What is Atrial Fibrillation? • Why AFib Matters • Understand your Risk for AFib Children • Symptoms of ...

  3. Atrial fibrillation (acute onset)

    PubMed Central

    2014-01-01

    Introduction Acute atrial fibrillation is rapid, irregular, and chaotic atrial activity of recent onset. Various definitions of acute atrial fibrillation have been used in the literature, but for the purposes of this review we have included studies where atrial fibrillation may have occurred up to 7 days previously. Risk factors for acute atrial fibrillation include increasing age, cardiovascular disease, alcohol, diabetes, and lung disease. Acute atrial fibrillation increases the risk of stroke and heart failure. The condition resolves spontaneously within 24 to 48 hours in more than 50% of people; however, many people will require interventions to control heart rate or restore sinus rhythm. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of interventions to prevent embolism, for conversion to sinus rhythm, and to control heart rate in people with recent-onset atrial fibrillation (within 7 days) who are haemodynamically stable? We searched: Medline, Embase, The Cochrane Library, and other important databases up to April 2014 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 26 studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review, we present information relating to the effectiveness and safety of the following interventions: amiodarone, antithrombotic treatment before cardioversion, atenolol, bisoprolol, carvedilol, digoxin, diltiazem, direct current cardioversion, flecainide, metoprolol, nebivolol, propafenone, sotalol, timolol, and verapamil. PMID:25430048

  4. Atrial Septal Defect (For Kids)

    MedlinePlus

    ... Dictionary of Medical Words En Español What Other Kids Are Reading Taking Care of Your Ears Taking ... an X-ray Atrial Septal Defect KidsHealth > For Kids > Atrial Septal Defect Print A A A What's ...

  5. Can Atrial Fibrillation Be Prevented?

    MedlinePlus

    ... from the NHLBI on Twitter. How Can Atrial Fibrillation Be Prevented? Following a healthy lifestyle and taking ... for heart disease may help you prevent atrial fibrillation (AF). These steps include: Following a heart healthy ...

  6. Stroke Prevention in Atrial Fibrillation

    MedlinePlus

    ... Association Cardiology Patient Page Stroke Prevention in Atrial Fibrillation Christian T. Ruff Download PDF https://doi.org/ ... an irregular and fast heartbeat. What Causes Atrial Fibrillation? Several factors and medical conditions make it more ...

  7. Loss of atrial contractility is primary cause of atrial dilatation during first days of atrial fibrillation.

    PubMed

    Schotten, Ulrich; de Haan, Sunniva; Neuberger, Hans-Ruprecht; Eijsbouts, Sabine; Blaauw, Yuri; Tieleman, Robert; Allessie, Maurits

    2004-11-01

    Atrial fibrillation (AF) induces a progressive dilatation of the atria which in turn might promote the arrhythmia. The mechanism of atrial dilatation during AF is not known. To test the hypothesis that loss of atrial contractile function is a primary cause of atrial dilatation during the first days of AF, eight goats were chronically instrumented with epicardial electrodes, a pressure transducer in the right atrium, and piezoelectric crystals to measure right atrial diameter. AF was induced with the use of repetitive burst pacing. Atrial contractility was assessed during sinus rhythm, atrial pacing (160-, 300-, and 400-ms cycle length), and electrically induced AF. The compliance of the fibrillating right atrium was measured during unloading the atria with diuretics and loading with 1 liter of saline. All measurements were repeated after 6, 12, and 24 h of AF and then once a day during the first 5 days of AF. Recovery of the observed changes after spontaneous cardioversion was also studied. After 5 days of AF, atrial contractility during sinus rhythm or slow atrial pacing was greatly reduced. During rapid pacing (160 ms) or AF, the amplitude of the atrial pressure waves had declined to 20% of control. The compliance of the fibrillating atria increased twofold, whereas the right atrial pressure was unchanged. As a result, the mean right atrial diameter increased by approximately 12%. All changes were reversible within 3 days of sinus rhythm. We conclude that atrial dilatation during the first days of AF is due to an increase in atrial compliance caused by loss of atrial contractility during AF. Atrial compliance and size are restored when atrial contractility recovers after cardioversion of AF.

  8. [Metabolic syndrome and chronic persistent atrial fibrillation].

    PubMed

    Onuchina, E L; Solov'ev, O V; Mochalova, O V; Kononov, S K; Onuchin, S G

    2011-01-01

    The aim of the study was to elucidate specific features of chronic recurrent atrial fibrillation (AF) in patients with metabolic syndrome (MS) and disturbed carbohydrate metabolism compared with AF patients without MS. It enrolled 145 patients aged 44-83 years: 117 with abdominal obesity (BMI >30 kg/m2, waist circumference >80 and 94 cm in women and men respectively) including 30 without metabolic disturbances; 35 with impaired glucose tolerance (IGT), 52 with type 2 DM, and 28 controls without MS. Parameters measured included frequency and severity of AF, carbohydrate and lipid metabolism, albuminurea, C-reactive peptide level, quality of AH control, results of echocardiography and 24 hour ECG monitoring (sinus rhythm), and insulin resistance index (HOMA IRindex). Groups of AF and MS patients were dominated by women. The frequency and severity of AF relapses in MS patients were higher than in controls (especially in the presence of IGT and DM). IGT and DM2 associated with structural changes in myocardium (left atrial dilatation, prevalence of LV concentric hypertrophy, diastolic dysfunction) coupled to higher systolic AH and marked metabolic disorders (hyperglycemia, IR, elevated microalbuminurea and C-reactive protein level, dyslipidemia). These conditions contribute to the frequency and severity of AF relapses. Development of AF in MS is a multifactor problem necessitating strict control of AH, dyslipidemia, DM2 and IGT, reduction of body weight and abdominal obesity.

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

    PubMed Central

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

    2015-01-01

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

  10. Exploiting periodicity to extract the atrial activity in atrial arrhythmias

    NASA Astrophysics Data System (ADS)

    Llinares, Raul; Igual, Jorge

    2011-12-01

    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.

  11. Surgery for Atrial Fibrillation

    PubMed Central

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

    2015-01-01

    Synopsis Atrial fibrillation is the most common cardiac arrhythmia and its treatment options include drug therapy or, catheter-based or surgical interventions. The surgical treatment of atrial fibrillation has undergone multiple evolutions over the last several decades. The Cox-Maze procedure which was developed by James Cox in 1987 is a procedure where multiple surgical incisions are created along the atria to interrupt the electrical pathways thought to allow atrial fibrillation to persist. This procedure went on to become the gold standard for the surgical treatment of atrial fibrillation and is currently in its 4th iteration called the Cox-Maze IV. The Cox-Maze IV replaced the previous “cut-and-sew” method with a combination of cryoablation and bipolar RF ablation. The adaption of ablation technologies allowed the Cox-Maze IV procedure to be performed through a less invasive right minithoracotomy instead of a traditional sternotomy approach. The aim of this article is to review the indications and preoperative planning for performing a Cox-Maze IV procedure. A description of the operative techniques for both a sternotomy and right mini-thoracotomy approach will be discussed in addition to specific postoperative considerations. Finally, this article will review the literature describing the surgical results for both approaches including comparisons of the Cox-Maze IV to the previous “cut-and-sew” method. PMID:25443237

  12. Myocardial infarct associated with a partial thickness left atrial tear in a dog with mitral insufficiency.

    PubMed

    Sleeper, Meg M; Maczuzak, Meredith E; Bender, Susan J

    2015-09-01

    A 10-year-old male neutered cavalier King Charles Spaniel with a 1-year history of degenerative mitral valve disease presented for dyspnea and severe weakness. He was diagnosed with congestive heart failure, systolic dysfunction, presumptive myocardial infarction and a left atrial thrombus based on thoracic radiographs, electrocardiogram and echocardiographic findings. Clinical signs also suggested right foreleg embolism. The dog was euthanized due to the grave prognosis and a postmortem evaluation was performed. The postmortem examination confirmed myocardial infarction and was thought to be due to embolic showering from the thrombus attached to a partial thickness left atrial endocardial tear.

  13. Catapult launch-associated cardioversion of atrial fibrillation.

    PubMed

    Bohnker, B K; Feeks, E F; McEwen, G

    1993-10-01

    A patient is presented with new-onset atrial fibrillation. While being air-evacuated, he cardioverted during the acceleration associated with aircraft carrier catapult launch. This case suggests a possible myocardial response to the kinetic energy produced by the acceleration force, similar to the electrical energy commonly used for cardioversion. Cardioversion using acceleration forces is probably not a clinically useful modality; however, this case demonstrates the importance of acceleration forces on patients during medical evacuation from aircraft carriers.

  14. Posterior left atrial wall hematoma mimicking cystic intracavitary atrial mass.

    PubMed

    Bahnacy, Yasser; Suresh, Cheriyil; Dawoud, Hamed; Zubaid, Mohammad

    2010-10-01

    Atrial myxoma is the most common benign primary tumor of the heart most commonly in the left atrium (LA). Cystic or cavitated intracardiac masses are rare. We report the case of a 43-year-old male patient admitted with chest infection, hemoptysis, and severe respiratory distress, who had to be ventilated. Chest computed tomography showed bilateral lung consolidation with large mass occupying the region of the LA. Transthoracic echocardiography and transesophageal echocardiography showed a large intracavitary left atrial cystic mobile mass. Open-heart surgical exploration did not show any mass inside the LA. A posterior left atrial wall hematoma was found and evacuated. Biopsies confirmed the presence of blood clots. Posterior left atrial wall hematoma may appear as left atrial intracavitary cystic mass and should be included in the differential diagnosis of cystic left atrial mass.

  15. Genetics Home Reference: familial atrial fibrillation

    MedlinePlus

    ... Home Health Conditions familial atrial fibrillation familial atrial fibrillation Enable Javascript to view the expand/collapse boxes. ... PDF Open All Close All Description Familial atrial fibrillation is an inherited condition that disrupts the heart's ...

  16. Quantification of left and right atrial kinetic energy using four-dimensional intracardiac magnetic resonance imaging flow measurements.

    PubMed

    Arvidsson, Per M; Töger, Johannes; Heiberg, Einar; Carlsson, Marcus; Arheden, Håkan

    2013-05-15

    Kinetic energy (KE) of atrial blood has been postulated as a possible contributor to ventricular filling. Therefore, we aimed to quantify the left (LA) and right (RA) atrial blood KE using cardiac magnetic resonance (CMR). Fifteen healthy volunteers underwent CMR at 3 T, including a four-dimensional phase-contrast flow sequence. Mean LA KE was lower than RA KE (1.1 ± 0.1 vs. 1.7 ± 0.1 mJ, P < 0.01). Three KE peaks were seen in both atria: one in ventricular systole, one during early ventricular diastole, and one during atrial contraction. The systolic LA peak was significantly smaller than the RA peak (P < 0.001), and the early diastolic LA peak was larger than the RA peak (P < 0.05). Rotational flow contained 46 ± 7% of total KE and conserved energy better than nonrotational flow did. The KE increase in early diastole was higher in the LA (P < 0.001). Systolic KE correlated with the combination of atrial volume and systolic velocity of the atrioventricular plane displacement (r(2) = 0.57 for LA and r(2) = 0.64 for RA). Early diastolic KE of the LA correlated with left ventricle (LV) mass (r(2) = 0.28), however, no such correlation was found in the right heart. This suggests that LA KE increases during early ventricular diastole due to LV elastic recoil, indicating that LV filling is dependent on diastolic suction. Right ventricle (RV) relaxation does not seem to contribute to atrial KE. Instead, RA KE generated during ventricular systole may be conserved in a hydraulic "flywheel" and transferred to the RV through helical flow, which may contribute to RV filling.

  17. A new atrial septostomy technique.

    PubMed

    Park, S C; Zuberbuhler, J R; Neches, W H; Lenox, C C; Zoltun, R A

    1975-01-01

    Balloon atrial septostomy is usually ineffective if the atrial septum is thickened. A technique for incising the atrial septum is described. A no. 6 French catheter was modified to enclose a tiny surgical blade. The distal end of the blade was pivoted to the catheter tip, and the proximal end was attached to a guide wire in the catheter lumen. Advancing the guide wire protruded the blade through a slit in the long axis of the tip of the catheter. Atrial septostomy was performed in five newborn lambs in vivo and in adult dog hearts and human hearts in vitro by advancing the catheter tip across the atrial septum with the blade retracted and withdrawing it to the right atrium with the blade extended. Eight to 12 mm lacerations of the atrial septum were produced and could be extended by subsequent balloon septostomy. The technique may be useful when balloon septostomy has been ineffective.

  18. Left atrial Frank–Starling law assessed by real‐time, three‐dimensional echocardiographic left atrial volume changes

    PubMed Central

    Anwar, Ashraf M; Geleijnse, Marcel L; Soliman, Osama I I; Nemes, Attila; Cate, Folkert J ten

    2007-01-01

    Background The Frank–Starling law describes the relation between left ventricular volume and function. However, only a few studies have described the relation between left atrial volume (LAV) and function. Objective To describe an LA Frank–Starling law by studying changes in LAV measured by real‐time, three‐dimensional echocardiography (RT3DE). Methods LAV was calculated by RT3DE in 70 patients at end‐systole (LAVmax), end‐diastole (LAVmin) and pre‐atrial contraction (LAVpre‐A). According to LAVmax, patients were classified into three groups: LAVmax <50 ml (group I), LAVmax 50–70 ml (group II) and LAVmax >70 ml (group III). Calculated indices of LA pump function were active atrial stroke volume (SV), defined as LAVpre‐A – LAVmin, and active atrial emptying fraction (EF), defined as active atrial SV/LAVpre‐A ×100% Results Active atrial SV was significantly higher in group II than in group I (mean (SD) 19.0 (9.2) vs 8.2 (4.9) ml, p<0.0001), in group III it was non‐significantly lower than in group II (16.7 (12.5) vs 19.0 (9.2) ml). Active atrial SV correlated well with LAVpre‐A (r = 0.56, p<0.001), but decreased with larger LAVpre‐A. Active atrial EF tended to be higher in group II than in group I (43.1 (18.2) vs 33.2 (17.5), p<0.10), in group III it was significantly lower than in group II (26.2 (18.5) vs 43.1 (18.2), p<0.01). Conclusion A Frank–Starling mechanism in the left atrium could be described by RT3DE, shown by an increase in LA contractility in response to an increase in LA preload up to a point, beyond which LA contractility decreased. PMID:17502327

  19. Atrial metabolism and tissue perfusion as determinants of electrical and structural remodelling in atrial fibrillation.

    PubMed

    Opacic, Dragan; van Bragt, Kelly A; Nasrallah, Hussein M; Schotten, Ulrich; Verheule, Sander

    2016-04-01

    Atrial fibrillation (AF) is the most common tachyarrhythmia in clinical practice. Over decades of research, a vast amount of knowledge has been gathered about the causes and consequences of AF related to cellular electrophysiology and features of the tissue structure that influence the propagation of fibrillation waves. Far less is known about the role of myocyte metabolism and tissue perfusion in the pathogenesis of AF. However, the rapid rates of electrical activity and contraction during AF must present an enormous challenge to the energy balance of atrial myocytes. This challenge can be met by scaling back energy demand and by increasing energy supply, and there are several indications that both phenomena occur as a result of AF. Still, there is ample evidence that these adaptations fall short of redressing this imbalance, which may represent a driving force for atrial electrical as well as structural remodelling. In addition, several 'metabolic diseases' such as diabetes, obesity, and abnormal thyroid function precipitate some well-known 'culprits' of the AF substrate such as myocyte hypertrophy and fibrosis, while some other AF risk factors, such as heart failure, affect atrial metabolism. This review provides an overview of metabolic and vascular alterations in AF and their involvement in its pathogenesis.

  20. Echocardiographic Reference Values for Right Atrial Size in Children with and without Atrial Septal Defects or Pulmonary Hypertension.

    PubMed

    Koestenberger, Martin; Burmas, Ante; Ravekes, William; Avian, Alexander; Gamillscheg, Andreas; Grangl, Gernot; Grillitsch, Marlene; Hansmann, Georg

    2016-04-01

    Right atrial (RA) size may become a very useful, easily obtainable, echocardiographic variable in patients with congenital heart disease (CHD) with right-heart dysfunction; however, according studies in children are lacking. We investigated growth-related changes of RA dimensions in healthy children. Moreover, we determined the predictive value of RA variables in both children with secundum atrial septal defect (ASD) and children with pulmonary hypertension (PH) secondary to CHD (PH-CHD). This is a prospective study in 516 healthy children, in 80 children with a secundum ASD (>7 mm superior-inferior dimension), and in 42 children with PH-CHD. We determined three RA variables, i.e., end-systolic major-axis length, end-systolic minor-axis length, and end-systolic area, stratified by age, body weight, length, and surface area. RA end-systolic length and area z scores were increased in children with ASD and PH-CHD when compared to those variables in the healthy control population. Using the Youden Index to determine the best cutoff scores in sex- and age-specific RA dimensions, we observed a sensitivity and specificity up to 94 and 91 %, respectively, in ASD children and 98 and 94 %, respectively, in PH-CHD children. We provide normal values (z scores -2 to +2) for RA size and area in a representative, large pediatric cohort. Enlarged RA variables with scores >+2 were predictive of secundum ASD and PH-CHD. Two-dimensional determination of RA size can identify enlarged RAs in the setting of high volume load (ASD) or pressure load (PH-CHD).

  1. Electrocardiographic detection of hypertensive left atrial enlargement in the presence of obesity: re-calibration against cardiac magnetic resonance.

    PubMed

    Rodrigues, J C L; Erdei, T; Dastidar, A G; McIntyre, B; Burchell, A E; Ratcliffe, L E K; Hart, E C; Hamilton, M C K; Paton, J F R; Nightingale, A K; Manghat, N E

    2017-03-01

    Left atrial enlargement (LAE) has adverse prognostic implications in hypertension. We sought to determine the accuracy of five electrocardiogram (ECG) criteria for LAE in hypertension relative to cardiac magnetic resonance (CMR) gold standard and investigate the effect of concomitant obesity. One hundred and thirty consecutive patients (age: 51.4±15.1 years, 47% male, 51% obese, systolic blood pressure (BP): 171±29 mm Hg, diastolic BP: 97±15 mm Hg) referred for CMR (1.5 T) from a tertiary hypertension clinic were included. Patients with concomitant cardiac pathology were excluded. ECGs were assessed blindly for the following: (1) P-wave >110 ms, (2) P-mitrale, (3) P-wave axis <30°, (4) area of negative P-terminal force in V1 >40 ms.mm and (5) positive P-terminal force in augmented vector left (aVL) >0.5 mm. Left atrial volume ≥55 ml m(-2), measured blindly by CMR, was defined as LAE. Sensitivity, specificity, positive predictive value, negative predictive value, accuracy and area under the receiver operator curve were calculated. The prevalence of LAE by CMR was 26%. All the individual ECG LAE criteria were more specific than sensitive, with specificities ranging from 70% (P-axis <30(o)) to 99% (P-mitrale). Obesity attenuated the specificity of most of the individual ECG LAE criteria. Obesity correlated with significant lower specificity (48% vs 65%, P<0.05) and a trend towards lower sensitivity (59 vs 43%, P=0.119) when ≥1 ECG LAE criteria were present. Individual ECG criteria of LAE in hypertension are specific, but not sensitive, at identifying LAE. The ECG should not be used to excluded LAE in hypertension, particularly in obese subjects.

  2. Renal Denervation Suppresses the Inducibility of Atrial Fibrillation in a Rabbit Model for Atrial Fibrosis

    PubMed Central

    Zhou, Genqing; Chen, Songwen; Ouyang, Ping; Liu, Shaowen

    2016-01-01

    Renal denervation (RD) was reported to reduce the susceptibility of atrial fibrillation (AF), but the underlying mechanism has not been well understood. This study was performed to investigate the effect of RD on the inducibility of AF in a rabbit model for atrial fibrosis and to explore the potential mechanisms. Thirty-five rabbits were randomly assigned into sham-operated group (n = 12), abdominal aortic constriction (AAC) group (n = 12) and AAC with RD (AAC-RD) group (n = 11). The incidence of AF induced by burst pacing in atriums was determined. Blood was collected to measure the levels of rennin, angiotensin II and aldosterone. Atrial samples were preserved to evaluate protein and gene expression of collagen, connective tissue growth factor (CTGF) and transforming growth factor-β1 (TGF-β1). Our data suggested cardiac structure remodeling and atrial fibrosis were successfully induced by AAC. Compared with the AAC group, the AAC-RD rabbits had smaller ascending aortic diameter and left ventricular end-systolic diameter. For burst pacing at the left atrium (LA), AF was induced in two of the 12 rabbits in the sham-operated group, 10 of the 12 rabbits in the AAC group, and 2 of the 11 rabbits in the AAC-RD group, with great difference among the three groups (P = 0.001). The percentage of LA burst stimulations with induced AF achieved 47.2% in the AAC group, which was higher than those in both the AAC-RD (12.1%) and the Sham-operated (5.6%) groups. Significantly increasing intercellular space in the AAC group (P<0.001) compared with the sham-operated rabbits. RD clearly decreased the volume fraction of collagen in LA and right atrium compared with that of the AAC group (P< 0.01). AAC-induced elevation of collagen I, CTGF and TGF-β1 was suppressed by RD. In conclusion, RD suppressed the inducibility of AF in a rabbit model for pressure associated atrial fibrosis, potentially by modulating renin-angiotensin-aldosterone system and decreasing pro-fibrotic factors

  3. Atrial fibrillation in the elderly

    PubMed Central

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

    2012-01-01

    This review discusses atrial fibrillation according to the guidelines of Brazilian Society of Cardiac Arrhythmias and the Brazilian Cardiogeriatrics Guidelines. We stress the thromboembolic burden of atrial fibrillation and discuss how to prevent it as well as the best way to conduct cases of atrial fibrillatios in the elderly, reverting the arrhythmia to sinus rhythm, or the option of heart rate control. The new methods to treat atrial fibrillation, such as radiofrequency ablation, new oral direct thrombin inhibitors and Xa factor inhibitors, as well as new antiarrhythmic drugs, are depicted. PMID:22916053

  4. The atrial natriuretic factor.

    PubMed Central

    Genest, J

    1986-01-01

    In less than three years since the rapid and potent natriuretic response to intravenous injection of atrial myocardial extract in rats was reported the factor responsible for the diuretic, natriuretic, and vasodilating activity of the atrial homogenates was isolated, its chemical structure elucidated, and its total synthesis achieved. Also the cDNA and the gene encoding for the atrial natriuretic factor in mice, rats, and man have been cloned and the chromosomal site identified. The major effects of this hormone are vasodilatation, prevention and inhibition of the contraction induced by noradrenaline and angiotensin II, diuresis, and natriuresis associated in most instances with a pronounced increase in glomerular filtration rate and filtration fraction, inhibition of aldosterone secretion, and considerable stimulation of particulate guanylate cyclase activity. High density specific binding sites have been demonstrated in the zona glomerulosa of the adrenal cortex, in the renal glomeruli, and in the collecting ducts, and in the brain areas involved in the regulation of blood pressure and of sodium and water (AV3V region, subfornical organ, nucleus tractus solitarius, area postrema). Images Fig 1 Fig 5 PMID:2945572

  5. Atrial Fibrillation: The Science behind Its Defiance

    PubMed Central

    Czick, Maureen E.; Shapter, Christine L.; Silverman, David I.

    2016-01-01

    Atrial fibrillation (AF) is the most prevalent arrhythmia in the world, due both to its tenacious treatment resistance, and to the tremendous number of risk factors that set the stage for the atria to fibrillate. Cardiopulmonary, behavioral, and psychological risk factors generate electrical and structural alterations of the atria that promote reentry and wavebreak. These culminate in fibrillation once atrial ectopic beats set the arrhythmia process in motion. There is growing evidence that chronic stress can physically alter the emotion centers of the limbic system, changing their input to the hypothalamic-limbic-autonomic network that regulates autonomic outflow. This leads to imbalance of the parasympathetic and sympathetic nervous systems, most often in favor of sympathetic overactivation. Autonomic imbalance acts as a driving force behind the atrial ectopy and reentry that promote AF. Careful study of AF pathophysiology can illuminate the means that enable AF to elude both pharmacological control and surgical cure, by revealing ways in which antiarrhythmic drugs and surgical and ablation procedures may paradoxically promote fibrillation. Understanding AF pathophysiology can also help clarify the mechanisms by which emerging modalities aiming to correct autonomic imbalance, such as renal sympathetic denervation, may offer potential to better control this arrhythmia. Finally, growing evidence supports lifestyle modification approaches as adjuncts to improve AF control. PMID:27699086

  6. Two-dimensional echocardiographic determination of left atrial emptying volume: a noninvasive index in quantifying the degree of nonrheumatic mitral regurgitation.

    PubMed

    Ren, J F; Kotler, M N; DePace, N L; Mintz, G S; Kimbiris, D; Kalman, P; Ross, J

    1983-10-01

    Several noninvasive techniques, including radionuclide angiography and Doppler echocardiography, have attempted to measure the regurgitant volume in patients with mitral regurgitation; however, none of these techniques are entirely satisfactory. Utilizing a computerized light pen method for tracing the left atrial endocardial border during systole and diastole in two orthogonal planes (apical four and two chamber views), biplane volume determinations were calculated in 12 normal subjects and 30 patients with nonrheumatic mitral regurgitation. Left atrial emptying volume determinations were performed by subtracting the left atrial end-diastolic volume from the left atrial end-systolic volume. The degree of mitral regurgitation was visually assessed as normal (0, trivial, Group I, 12 patients), mild (1+, Group II, 4 patients), moderate (2+, Group III, 8 patients), moderately severe (3+, Group IV, 12 patients) and severe (4+, Group V, 6 patients) by contrast left ventricular angiography and also quantitatively by regurgitant fraction at cardiac catheterization. All 18 patients with moderately severe (Group IV) and severe (Group V) mitral regurgitation had a left atrial emptying volume greater than 40 ml compared with none of the normal subjects and patients with mild (Group II) or moderate (Group III) mitral regurgitation. There was good correlation between left atrial emptying volume and mitral regurgitant fraction (r = 0.85, p less than 0.01). Thus, in patients with nonrheumatic mitral regurgitation, left atrial emptying volume is useful in separating mild from severe mitral regurgitation.

  7. Effect of coronary artery bypass graft surgery on left ventricular systolic function

    PubMed Central

    Koene, Ryan J.; Kealhofer, Jessica V.; Adabag, Selcuk; Vakil, Kairav

    2017-01-01

    Background Changes in left ventricular (LV) systolic function in response to coronary artery bypass grafting (CABG) have not been fully assessed. Methods Between January 2001 and December 2014, 2,838 consecutive patients underwent isolated CABG at the Minneapolis Veterans Affairs Health Care System. Of these, 375 had echocardiographic assessment of LV function before (within 6 months) and after (3 to 24 months) CABG and were included in this analysis. Results While the mean LV ejection fraction (LVEF) did not change following CABG [(49±13)% vs. (49±12)%, P=0.51], LVEF decreased in the subgroup with normal (≥50%) pre-operative LVEF [from (59±5)% to (56±9)%, P<0.001] and improved in those with decreased (<50%) pre-operative LVEF [from (36±9)% to (41±12)%, P<0.001]. There was a significant reduction in LV internal diameter during end-diastole (LVIDd) (5.4±0.8 vs. 5.3±0.9, P=0.002) and an increase in left atrial diameter (LAD) (4.4±0.7 vs. 4.6±0.7, P<0.001). There were no perioperative changes in LV internal diameter during end-systole, LV mass, posterior wall thickness, or septal wall thickness. LVEF improved by >5% in 24% of the study population, did not change (+/− 5%) in 55%, and worsened by >5% in 21%. Patients with improved EF were less often diabetic and had lower pre-operative LVEF, and greater LV dimensions at baseline. Conclusions After CABG, there was a decrease in LVIDd and an increase in LAD. Also, a decrease in LV systolic function with CABG was observed in patients with normal pre-operative LVEF and an improvement in LV systolic function was observed in patients with decreased pre-operative LVEF. PMID:28275473

  8. Aortic root and left atrial wall motion. An echocardiographic study.

    PubMed Central

    Akgün, G; Layton, C

    1977-01-01

    The echocardiographically recorded movement of the aortic root was studied by analysing the relation between posterior aortic wall motion and other intracardiac events. The systolic anterior movement of the aortic root continued beyond aortic valve closure and in cases with mitral regurgitation began significantly earlier than in normal subjects. The diastolic rapid posterior movement began after mitral valve opening but did not occur in patients with mitral stenosis. The total amplitude of aortic root motion was increased in patients with mitral regurgitation, diminished in cases of mitral stenosis, and was normal with aortic regurgitation. In patients with atrioventricular block an abrupt posterior movement followed the P wave of the electrocardiogram irrespective of its timing in diastole. These observations correlate with the expected changes in left atrial volume during the cardiac cycle both in the normal subjects and patients with heart disease. The results support the hypothesis that phasic changes in left atrial dimension are largely responsible for the echocardiographically observed movement of the aortic root and indicate a potential role for echocardiography in the analysis of left atrial events. Images PMID:911559

  9. Atrial Cardiopathy: A Broadened Concept of Left Atrial Thromboembolism Beyond Atrial Fibrillation

    PubMed Central

    Kamel, Hooman; Okin, Peter M.; Longstreth, W. T.; Elkind, Mitchell S.V.; Soliman, Elsayed Z.

    2016-01-01

    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

  10. Left Atrial Epicardial Adiposity and Atrial Fibrillation

    PubMed Central

    Batal, Omar; Schoenhagen, Paul; Shao, Mingyuan; Ayyad, Ala Eddin; Van Wagoner, David R.; Halliburton, Sandra S.; Tchou, Patrick J.; Chung, Mina K.

    2010-01-01

    Background Atrial fibrillation (AF) has been linked to inflammatory factors and obesity. Epicardial fat is a source of several inflammatory mediators related to the development of coronary artery disease. We hypothesized that periatrial fat may have a similar role in the development of AF. Methods and Results Left atrium (LA) epicardial fat pad thickness was measured in consecutive cardiac CT angiograms performed for coronary artery disease or AF. Patients were grouped by AF burden: no (n=73), paroxysmal (n=60), or persistent (n=36) AF. In a short-axis view at the mid LA, periatrial epicardial fat thickness was measured at the esophagus (LA-ESO), main pulmonary artery, and thoracic aorta; retrosternal fat was measured in axial view (right coronary ostium level). LA area was determined in the 4-chamber view. LA-ESO fat was thicker in patients with persistent AF versus paroxysmal AF (P=0.011) or no AF (P=0.003). LA area was larger in patients with persistent AF than paroxysmal AF (P=0.004) or without AF (P<0.001). LA-ESO was a significant predictor of AF burden even after adjusting for age, body mass index, and LA area (odds ratio, 5.30; 95% confidence interval, 1.39 to 20.24; P=0.015). A propensity score–adjusted multivariable logistic regression that included age, body mass index, LA area, and comorbidities was also performed and the relationship remained statistically significant (P=0.008). Conclusions Increased posterior LA fat thickness appears to be associated with AF burden independent of age, body mass index, or LA area. Further studies are necessary to examine cause and effect, and if inflammatory, paracrine mediators explain this association. PMID:20504944

  11. Uncontrolled ventricular rate in atrial fibrillation. A manifestation of dissimilar atrial rhythms.

    PubMed Central

    Leier, C V; Johnson, T M; Lewis, R P

    1979-01-01

    A patient with coarse atrial fibrillation and a rapid ventricular response developed periods of high grade atrioventricular block interpersed with periods of rapid ventricular conduction after the administration of digitalis and propranolol. Intracardiac atrial recordings showed similar atrial rhythms of high right atrial flutter and left atrial fibrillation. The low right atrial recordings showed flutter during the periods of fast ventricular rates and fibrillation during periods of slower ventricular rates. Images PMID:475927

  12. Noninvasive assessment of left atrial maximum dP/dt by a combination of transmitral and pulmonary venous flow

    NASA Technical Reports Server (NTRS)

    Nakatani, S.; Garcia, M. J.; Firstenberg, M. S.; Rodriguez, L.; Grimm, R. A.; Greenberg, N. L.; McCarthy, P. M.; Vandervoort, P. M.; Thomas, J. D.

    1999-01-01

    OBJECTIVES: The study assessed whether hemodynamic parameters of left atrial (LA) systolic function could be estimated noninvasively using Doppler echocardiography. BACKGROUND: Left atrial systolic function is an important aspect of cardiac function. Doppler echocardiography can measure changes in LA volume, but has not been shown to relate to hemodynamic parameters such as the maximal value of the first derivative of the pressure (LA dP/dt(max)). METHODS: Eighteen patients in sinus rhythm were studied immediately before and after open heart surgery using simultaneous LA pressure measurements and intraoperative transesophageal echocardiography. Left atrial pressure was measured with a micromanometer catheter, and LA dP/dt(max) during atrial contraction was obtained. Transmitral and pulmonary venous flow were recorded by pulsed Doppler echocardiography. Peak velocity, and mean acceleration and deceleration, and the time-velocity integral of each flow during atrial contraction was measured. The initial eight patients served as the study group to derive a multilinear regression equation to estimate LA dP/dt(max) from Doppler parameters, and the latter 10 patients served as the test group to validate the equation. A previously validated numeric model was used to confirm these results. RESULTS: In the study group, LA dP/dt(max) showed a linear relation with LA pressure before atrial contraction (r = 0.80, p < 0.005), confirming the presence of the Frank-Starling mechanism in the LA. Among transmitral flow parameters, mean acceleration showed the strongest correlation with LA dP/dt(max) (r = 0.78, p < 0.001). Among pulmonary venous flow parameters, no single parameter was sufficient to estimate LA dP/dt(max) with an r2 > 0.30. By stepwise and multiple linear regression analysis, LA dP/dt(max) was best described as follows: LA dP/dt(max) = 0.1 M-AC +/- 1.8 P-V - 4.1; r = 0.88, p < 0.0001, where M-AC is the mean acceleration of transmitral flow and P-V is the peak velocity

  13. [Perioperative management of atrial fibrillation].

    PubMed

    Arguis, M J; Navarro, R; Regueiro, A; Arbelo, E; Sierra, P; Sabaté, S; Galán, J; Ruiz, A; Matute, P; Roux, C; Gomar, C; Rovira, I; Mont, L; Fita, G

    2014-05-01

    Atrial fibrillation is a frequent complication in the perioperative period. When it appears there is an increased risk of perioperative morbidity due to stroke, thromboembolism, cardiac arrest, myocardial infarction, anticoagulation haemorrhage, and hospital readmissions. The current article focuses on the recommendations for the management of perioperative atrial fibrillation based on the latest Clinical Practice Guidelines on atrial fibrillation by the European Society of Cardiology and the Spanish Society of Cardiology. This article pays special attention to the preoperative management, as well as to the acute perioperative episode. For this reason, the latest recommendations for the control of cardiac frequency, antiarrhythmic treatment and anticoagulation are included.

  14. The Preoperative Patient With a Systolic Murmur

    PubMed Central

    Cowie, Brian

    2015-01-01

    Context: Patients with undifferentiated systolic murmurs present commonly during the perioperative period. Traditional bedside assessment and auscultation has not changed significantly in almost 200 years and relies on interpreting indirect acoustic events as a means of evaluating underlying cardiac pathology. This is notoriously inaccurate, even in expert cardiology hands, since many different valvular and cardiac diseases present with a similar auditory signal. Evidence Acquisition: The data on systolic murmurs, physical examination, perioperative valvular disease in the setting of non-cardiac surgery is reviewed. Results: Significant valvular heart disease increases perioperative risk in major non-cardiac surgery and increases long term patient morbidity and mortality. We propose a more modern approach to physical examination that incorporates the use of focused echocardiography to allow direct visualization of cardiac structure and function. This improves the diagnostic accuracy of clinical assessment, allows rational planning of surgery and anaesthesia technique, risk stratification, postoperative monitoring and appropriate referral to physicians and cardiologists. Conclusions: With a thorough preoperative assessment incorporating focused echocardiography, anaesthetists are in the unique position to enhance their role as perioperative physicians and influence short and long term outcomes of their patients. PMID:26705529

  15. A possible role of atrial natriuretic peptide in ethanol-induced acute diuresis

    SciTech Connect

    Colantonio, D.; Casale, R.; Mammarella, M.; Pasqualetti, P. ); Desiati, P.; De Michele, G. )

    1991-01-01

    The acute effects of ethanol on plasma atrial natriuretic peptide levels were investigated in 4 clinically healthy males, aged 24-26 years, consumed either 750 ml of water as a control study, or the same beverage with 1 ml/kg alcohol added, which increased the plasma alcohol concentration to 99.12{plus minus}15.10 mg/dl at 60 min. Plasma atrial natriuretic peptide levels were significantly higher in the alcohol study compared to the control study at each time point, and with a peak at 10 min. Atrial natriuretic peptide levels showed a positive significant correlation with plasma antidiuretic hormone in the control group, while no relationship was found between the two peptides in the alcohol study. Moreover, a significant correlation exists between plasma atrial natriuretic peptide levels and systolic arterial blood pressure, and heart rate, and between the variations in atrial natriuretic peptide values and the variations in plasma sodium, serum ethanol, and plasma osmolality in the alcohol study. Acute ethanol intake causes an increase in urinary volume, and a decrease in urinary potassium excretion and urinary osmolality, and no change in urinary sodium excretion.

  16. Right atrial morphology and function in patients with systemic sclerosis compared to healthy controls: a two-dimensional strain study.

    PubMed

    D'Andrea, Antonello; D'Alto, Michele; Di Maio, Marco; Vettori, Serena; Benjamin, Nicola; Cocchia, Rosangela; Argiento, Paola; Romeo, Emanuele; Di Marco, Giovanni; Russo, Maria Giovanna; Valentini, Gabriele; Calabrò, Raffaele; Bossone, Eduardo; Grünig, Ekkehard

    2016-07-01

    Enlargement and dysfunction of the right atrium might be an early sign for pulmonary hypertension in systemic sclerosis (SSc). This is the first study to analyse right atrial morphology and function in SSc patients compared to healthy controls by speckle-tracking two-dimensional strain echocardiography (2DSE) at rest and during exercise. Furthermore, right atrial function was correlated with further clinical findings. Adult patients with SSc for >3 years (n = 90) and 55 age- and gender-matched healthy controls underwent a panel of non-invasive assessments including transthoracic echocardiography, pulsed Doppler myocardial imaging and 2DSE at rest and during exercise. Furthermore, serological tests and high-resolution chest computed tomography were performed. SSc patients showed significant impairment of right atrial function and the right atrial enlargement, measured by 2DSE at rest and during exercise compared to controls (both p < 0.001). These findings were more evident in SSc patients with pulmonary fibrosis (p < 0.001) and in patients with high pulmonary artery systolic pressures (PAPs) during exercise. In the SSC patients, right atrial lateral strain was significantly associated with PAPs during effort, right atrial area, left ventricle stroke volume and inferior vena cava diameter using multivariable analysis. The findings of this study suggest that a high proportion of SSc patients reveal right atrial dysfunction even without manifest pulmonary hypertension. Impaired right atrial function occurred mostly in patients with pulmonary fibrosis and/or elevated PAPs during exercise, was independently associated with prognostic factors and may therefore be useful for risk stratification. Further studies are needed to analyse if right atrial dysfunction assessed by 2DSE may help to improve early diagnosis of pulmonary hypertension.

  17. Atrial Septal Defect (For Kids)

    MedlinePlus

    ... wall called the septum that normally separates the blue and red blood. In a person with an atrial septal defect, there's an opening in that wall. This hole in the wall lets oxygen-rich blood from ...

  18. Left Atrial Mechanical Function and Aortic Stiffness in Middle-aged Patients with the First Episode of Atrial Fibrillation

    PubMed Central

    Kılıcgedik, Alev; Ç Efe, Suleyman; Gürbüz, Ahmet S; Acar, Emrah; Yılmaz, Mehmet F; Erdoğan, Aslan; Kahveci, Gökhan; Izgi, Ibrahim A; Kirma, Cevat

    2017-01-01

    Background: In the early stages of atrial remodeling, aortic stiffness might be an indication of an atrial myopathy, in particular, atrial fibrosis. This study aimed to investigate the association between left atrial (LA) mechanical function, assessed by two-dimensional speckle tracking echocardiography, and aortic stiffness in middle-aged patients with the first episode of nonvalvular atrial fibrillation (AF). Methods: This prospective study included 34 consecutive patients with the first episode of AF, who were admitted to Kartal Koşuyolu Research and Training Hospital between May 2013 and October 2015, and 31 age- and gender-matched healthy controls. During the 1st month (mostly in the first 2 weeks) following their first admission, 34 patients underwent the first pulse wave measurements. Then, 21 patients were recalled for their second pulse wave measurement at 11.8 ± 6.0 months following their initial admission. Echocardiographic and pulse wave findings were compared between these 34 patients and 31 healthy controls. We also compared the pulse wave and echocardiographic findings between the first and second measurements in 21 patients. Results: Pulse wave analysis showed no significant differences between the AF patients and healthy controls with respect to PWV (10.2 ± 2.5 m/s vs. 9.7 ± 2.1 m/s; P = 0.370), augmentation pressure (9.6 ± 7.4 mmHg vs. 9.1 ± 5.7 mmHg; P = 0.740), and aortic pulse pressure (AoPP; 40.4 ± 14.0 mmHg vs. 42.1 ± 7.6 mmHg, P = 0.550). The first LA positive peak of strain was inversely related to the augmentation pressure (r = −0.30; P = 0.02) and aortic systolic pressure (r = −0.26, P = 0.04). Comparison between the two consecutive pulse wave measurements in 21 patients showed similar results, except for AoPP. In 21 patients, the AoPP at the second measurement (45.1 ± 14.1 mmHg) showed a significant increase compared with AoPP at the first measurement (39.0 ± 10.6 mmHg, P = 0.028), which was also higher than that of healthy

  19. Atrial fibrillation and anabolic steroids.

    PubMed

    Sullivan, M L; Martinez, C M; Gallagher, E J

    1999-01-01

    A young male bodybuilder, consuming large doses of anabolic steroids (AS), presented to the Emergency Department (ED) with symptomatic rapid atrial fibrillation (AF). Echocardiogram revealed significant septal hypokinesis, and posterior and septal wall thickness at the upper limit of normal for highly trained athletes. The atrial fibrillation had not recurred at 10 weeks after discontinuation of AS use. Consumption of these agents in athletes has been associated with hypertension, ischemic heart disease, hypertrophic cardiomyopathy, and sudden death.

  20. Rhythm control in atrial fibrillation.

    PubMed

    Piccini, Jonathan P; Fauchier, Laurent

    2016-08-20

    Many patients with atrial fibrillation have substantial symptoms despite ventricular rate control and require restoration of sinus rhythm to improve their quality of life. Acute restoration (ie, cardioversion) and maintenance of sinus rhythm in patients with atrial fibrillation are referred to as rhythm control. The decision to pursue rhythm control is based on symptoms, the type of atrial fibrillation (paroxysmal, persistent, or long-standing persistent), patient comorbidities, general health status, and anticoagulation status. Many patients have recurrent atrial fibrillation and require further intervention to maintain long term sinus rhythm. Antiarrhythmic drug therapy is generally recommended as a first-line therapy and drug selection is on the basis of the presence or absence of structural heart disease or heart failure, electrocardiographical variables, renal function, and other comorbidities. In patients who continue to have recurrent atrial fibrillation despite medical therapy, catheter ablation has been shown to substantially reduce recurrent atrial fibrillation, decrease symptoms, and improve quality of life, although recurrence is common despite continued advancement in ablation techniques.

  1. Preclinical Systolic and Diastolic Dysfunction in Metabolically Healthy and Unhealthy Obese Individuals

    PubMed Central

    Wang, Yi-Chih; Liang, Chang-seng; Gopal, Deepa M.; Ayalon, Nir; Donohue, Courtney; Santhanakrishnan, Rajalakshmi; Sandhu, Harpaul; Perez, Alejandro J.; Downing, Jill; Gokce, Noyan; Colucci, Wilson S.; Ho, Jennifer E.

    2015-01-01

    Background Despite the substantial overlap of obesity and metabolic disease, there is hetereogeneity with respect to cardiovascular risk. We sought to investigate preclinical differences in systolic and diastolic function in obesity, and specifically compare obese individuals with and without metabolic syndrome (MS). Methods and Results Obese individuals without cardiac disease with (OB/MS+, n=124) and without MS (OB/MS−, n=37) were compared to non-obese controls (n=29). Diastolic function was assessed by transmitral and tissue Doppler. Global longitudinal strain (LS) and time-based dyssynchrony were assessed by speckle tracking. Both Ob/MS− and OB/MS+ groups had similar ejection fraction but worse systolic mechanics as assessed by LS and dyssynchrony compared with non-obese controls. Specifically, OB/MS− had 2.5% lower LS (s.e. 0.7%, P=0.001 in multivariable-adjusted analyses) and 10.8 ms greater dyssynchrony (s.e. 3.3, P=0.002), and OB/MS+ had 1.0% lower LS (s.e. 0.3%, P<0.001) and 7.8 ms greater dyssynchrony (s.e. 1.5, P<0.001) compared with controls. Obesity was associated with impaired diastolic function regardless of MS status, as evidenced by greater left atrial diameter and left ventricular mass, though diastolic dysfunction was more pronounced in OB/MS+ compared with OB/MS− individuals. Conclusions Obesity is associated with subclinical differences in both systolic and diastolic function regardless of the presence or absence of MS, although MS appears to be associated with worse diastolic dysfunction. Compared to controls, ‘metabolically healthy’ obese had lower LS, greater dyssynchrony, and early diastolic dysfunction, supporting the notion that obesity per se may have adverse cardiovascular effects regardless of metabolic disease. PMID:26175540

  2. A Logical Characterization of Systolic Languages

    NASA Astrophysics Data System (ADS)

    Monti, Angelo; Peron, Adriano

    In this paper we study, in the framework of mathematical logic, ℒ(SBTA) i.e. the class of languages accepted by Systolic Binary Tree Automata. We set a correspondence (in the style of Büchi Theorem for regular languages) between ℒ(SBTA) and MSO[Sig], i.e. a decidable Monadic Second Order logic over a suitable infinite signature Sig. We also introduce a natural subclass of ℒ(SBTA) which still properly contains the class of regular languages and which is proved to be characterized by Monadic Second Order logic over a finite signature Sig' ⊂ Sig. Finally, in the style of McNaughton Theorem for star free regular languages, we introduce an expression language which precisely denotes the class of languages defined by the first order fragment of MSO[Sig'].

  3. Singular value decomposition with systolic arrays

    NASA Technical Reports Server (NTRS)

    Ipsen, I. C. F.

    1984-01-01

    Systolic arrays for determining the singular value decomposition of a mxn, m n, matrix A of bandwidth w are presented. After A has been reduced to bidiagonal form B by means of Givens plane rotations, the singular values of B are computed by the Golub-Reinsch iteration. The products of plane rotations form the matrices of left and right singular vectors. Assuming each processor can compute or supply a plane rotation, O(wn) processors accomplish the reduction to bidiagonal form in O(np) steps, where p is the number of superdiagonals. A constant number of processors then determines each singular value in about 6n steps. The singular vectors are computed by rerouting the rotations through the arrays used for the reduction to bidiagonal form, or else along the way by employing another rectangular array of O(wm) processors.

  4. [Morphological and functional parameters of the left ventricle (mass, wall thickness and end-systolic stress) in school children with different levels of blood pressure, at rest and during maximal exercise].

    PubMed

    Muñoz, S; Soltero, I; Onorato, E; Pietri, C; Zambrano, F

    1990-01-01

    Echocardiographically determined left ventricular mass, diastolic septal and posterior wall thickness and end-systolic wall stress, as well as electrocardiographic indexes of left ventricular enlargement (Sokolow-Lyon index and Romhilt-Estes score) and of left atrial enlargement (P terminal index) were correlated with resting and exercise systolic and diastolic blood pressures, and with several parameters of body size (weight, height, body surface area, Quetelet index), in 130 school children (61 boys, 69 girls) 6 to 15 years of age. Parameters of body size had a positive correlation both with systolic and diastolic blood pressures and with parameters of left ventricular size. Thus, the latter were adjusted for body surface area, for correlation with blood pressure. Left ventricular mass and diastolic septal and posterior wall thickness had a very poor correlation with resting and exercise diastolic blood pressures. Left ventricular mass and diastolic posterior wall thickness had a significantly higher correlation with peak exercise systolic blood pressure than with resting systolic blood pressure. End-systolic wall stress had a positive correlation with resting diastolic and systolic blood pressures. Electrocardiographic parameters of left ventricular and left atrial enlargement had a very poor correlation with resting and exercise blood pressure. Our findings suggest that early in life left ventricular mass and wall thickness are more closely related to maximal systolic blood pressure during physical exercise than to blood pressure in basal conditions. The electrocardiogram is an insensitive method to detect early modifications of left ventricular size in relation to different levels of blood pressure. The echocardiogram is the method of choice for this purpose.

  5. Right atrial tunnel to the left atrial appendage: a danger during balloon septostomy.

    PubMed

    Waldman, J D; McFeeley, P; Bornikova, L

    2001-01-01

    Right atrial tunnel to the left atrial appendage is a very rare anomaly not previously described. Per se, it has no physiological significance but is a source of potential disaster during balloon atrial septostomy. The precise anatomy is demonstrated and ways are proposed to avoid tearing the atrial wall during therapeutic cardiac catheterization.

  6. Late atypical atrial flutter after ablation of atrial fibrillation.

    PubMed

    Ferreira, Raquel; Primo, João; Adão, Luís; Gonzaga, Anabela; Gonçalves, Helena; Santos, Rui; Fonseca, Paulo; Santos, José; Gama, Vasco

    2016-10-01

    Cardiac surgery for structural heart disease (often involving the left atrium) and radiofrequency catheter ablation of atrial fibrillation have led to an increased incidence of regular atrial tachycardias, often presenting as atypical flutters. This type of flutter is particularly common after pulmonary vein isolation, especially after extensive atrial ablation including linear lesions and/or defragmentation. The authors describe the case of a 51-year-old man, with no relevant medical history, referred for a cardiology consultation in 2009 for paroxysmal atrial fibrillation. After failure of antiarrhythmic therapy, he underwent catheter ablation, with criteria of acute success. Three years later he again suffered palpitations and atypical atrial flutter was documented. The electrophysiology study confirmed the diagnosis of atypical left flutter and reappearance of electrical activity in the right inferior pulmonary vein. This vein was again ablated successfully and there has been no arrhythmia recurrence to date. In an era of frequent catheter ablation it is essential to understand the mechanism of this arrhythmia and to recognize such atypical flutters.

  7. Recursive least squares estimation and Kalman filtering by systolic arrays

    NASA Technical Reports Server (NTRS)

    Chen, M. J.; Yao, K.

    1988-01-01

    One of the most promising new directions for high-throughput-rate problems is that based on systolic arrays. In this paper, using the matrix-decomposition approach, a systolic Kalman filter is formulated as a modified square-root information filter consisting of a whitening filter followed by a simple least-squares operation based on the systolic QR algorithm. By proper skewing of the input data, a fully pipelined time and measurement update systolic Kalman filter can be achieved with O(n squared) processing cells, resulting in a system throughput rate of O (n).

  8. Surgical Ablation of Atrial Fibrillation.

    PubMed

    Ramlawi, Basel; Abu Saleh, Walid K

    2015-01-01

    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

  9. Atrial fibrillation in endurance athletes.

    PubMed

    Wilhelm, Matthias

    2014-08-01

    There is a growing population of veteran endurance athletes, regularly participating in training and competition. Although the graded benefit of exercise on cardiovascular health and mortality is well established, recent studies have raised concern that prolonged and strenuous endurance exercise may predispose to atrial and ventricular arrhythmias. Atrial fibrillation (AF) and atrial flutter are facilitated by atrial remodelling, atrial ectopy, and an imbalance of the autonomic nervous system. Endurance sports practice has an impact on all of these factors and may therefore act as a promoter of these arrhythmias. In an animal model, long-term intensive exercise training induced fibrosis in both atria and increased susceptibility to AF. While the prevalence of AF is low in young competitive athletes, it increases substantially in the aging athlete, which is possibly associated with an accumulation of lifetime training hours and participation in competitions. A recent meta-analysis revealed a 5-fold increased risk of AF in middle-aged endurance athletes with a striking male predominance. Beside physical activity, height and absolute left atrial size are independent risk factors for lone AF and the stature of men per se may explain part of their higher risk of AF. Furthermore, for a comparable amount of training volume and performance, male non-elite athletes exhibit a higher blood pressure at rest and peak exercise, a more concentric type of left ventricular remodelling, and an altered diastolic function, possibly contributing to a more pronounced atrial remodelling. The sports cardiologist should be aware of the distinctive features of AF in athletes. Therapeutic recommendations should be given in close cooperation with an electrophysiologist. Reduction of training volume is often not desired and drug therapy not well tolerated. An early ablation strategy may be appropriate for some athletes with an impaired physical performance, especially when continuation of

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

    PubMed

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

    2016-04-01

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

  11. Atrial Fibrillation Predictors: Importance of the Electrocardiogram.

    PubMed

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

    2016-01-01

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

  12. Left ventricular volumes and function during atrial pacing in coronary artery disease: a radionuclide angiographic study

    SciTech Connect

    Rozenman, Y.; Weiss, A.T.; Atlan, H.; Gotsman, M.S.

    1984-02-01

    This study set out to determine the pathophysiologic changes in the left ventricle during atrial pacing in 22 patients with coronary artery disease. Graduated right atrial pacing to a rate of 160 beats/min, or the induction of angina pectoris or significant ST depression was undertaken. Ventricular volumes were measured at rest and at rates of 100, 120, 140 and 160 beats/min using radionuclide angiography. The volumes at a pacing rate of 100 beats/min were used as a reference standard (100%). In the 22 patients with coronary artery disease, left ventricular end-diastolic volume decreased from 118 +/- 3% at rest to 80 +/- 5% at a rate of 160 beats/min; stroke volume from 121 +/- 3% to 54 +/- 5%; and ejection fraction (EF) from 49 +/- 3% to 37 +/- 5%. End-systolic volume decreased from 118 +/- 4% at rest, reached its minimal value of 94 +/- 5% at a rate of 120 beats/min and then increased slightly to 106 +/- 9% at 160 beats/min. Cardiac output and blood pressure did not change significantly. Compared to the control group of 10 normal subjects, the patients had a significantly smaller decrease in end-diastolic volume and end-systolic volume than in normal control subjects. EF in the normal subjects did not change. Blood pressure, cardiac output and stroke volume were similar in both groups. Atrial pacing tachycardia induced reversible ventricular dysfunction with a decrease in EF. Stroke volume was maintained because of relative ventricular dilatation.

  13. Atrial Myxoma: A Case Presentation and Review

    PubMed Central

    Cohen, Ronny; Singh, Gagandeep; Mena, Derrick; Garcia, Christine A.; Loarte, Pablo; Mirrer, Brooks

    2012-01-01

    Myxomas are the most common primary cardiac tumors, most frequently found in the left atrium. We present a case of an atrial myxoma. An in-depth review of atrial myxoma is presented, examining the important clinical symptoms and diagnostic indicators. The treatment of atrial myxoma is then discussed, with an emphasis on current therapies. An extensive literature review has been performed to present a comprehensive review of the causes, pathophysiology of atrial myxoma.

  14. Post-Acceleration Chaotic Atrial Rhythm

    DTIC Science & Technology

    1982-04-01

    atrial flutter or two discrete P-wave morphologies with the rate less fibrillation. than 100 bpm). and sinus bradycardia. An occasional The time...mulhilocal paroxysmal atrial tach.- cardia with cclic Wcnckchach phenomenon under observation examinations. The chaotic atrial rhythm in this case ji r 13...CHAOTIC ATRIAL RHYTHM Final Report 1 July 81 - 30 July 81 6. PERFORMING OIG. REPORT NUMBER 7. AUTHOR(s) 8 CONTRACT OR GRANT NUMBERS) r James E

  15. Silent Atrial Fibrillation and Cryptogenic Strokes.

    PubMed

    Dalen, James E; Alpert, Joseph S

    2017-03-01

    A new suspected cause of cryptic strokes is "silent atrial fibrillation." Pacemakers and other implanted devices allow continuous recording of cardiac rhythm for months or years. They have discovered that short periods of atrial fibrillation lasting minutes or hours are frequent and usually are asymptomatic. A meta-analysis of 50 studies involving more than 10,000 patients with a recent stroke found that 7.7% had new atrial fibrillation on their admitting electrocardiogram. In 3 weeks during and after hospitalization, another 16.9% were diagnosed. A total of 23.7% of these stroke patients had silent atrial fibrillation; that is, atrial fibrillation diagnosed after hospital admission. Silent atrial fibrillation is also frequent in patients with pacemakers who do not have a recent stroke. In a pooled analysis of 3 studies involving more than 10,000 patients monitored for 24 months, 43% had at least 1 day with atrial fibrillation lasting more than 5 minutes. Ten percent had atrial fibrillation lasting at least 12 hours. Despite the frequency of silent atrial fibrillation in these patients with multiple risk factors for stroke, the annual incidence of stroke was only 0.23%. When silent atrial fibrillation is detected in patients with recent cryptogenic stroke, anticoagulation is indicated. In patients without stroke, silent atrial fibrillation should lead to further monitoring for clinical atrial fibrillation rather than immediate anticoagulation, as some have advocated.

  16. Evaluation of right atrial function by two-dimensional speckle-tracking echocardiography in patients with right ventricular myocardial infarction.

    PubMed

    Nourian, Saeed; Hosseinsabet, Ali; Jalali, Arash; Mohseni-Badalabadi, Reza

    2017-01-01

    Right ventricular myocardial infarction (RVMI) damages the systolic and diastolic functions of the RV, so the right atrium interacts with the RV with an acutely altered function. The aim of our study was to compare right atrial function as evaluated by 2D speckle-tracking echocardiography (2DSTE) between patients with inferior wall myocardial infarction (INFMI) and patients affected by both inferior myocardial infarction and right ventricular myocardial infarction (INFMI + RVMI). Our study recruited 70 consecutive patients with INFMI (43 patients without RVMI and 27 patients with RVMI). Right atrial function was evaluated by 2DSTE. Early diastolic strain, systolic strain rate, absolute value of early diastolic strain rate, expansion index, and diastolic emptying index of the right atrium were reduced in the patients with INFMI + RVMI compared to the patients with INFMI. The area under the curve for early diastolic strain for INFMI diagnosis was 0.682 (p value = 0.011, 95 % CI 0.550-0.815). Right atrial early diastolic longitudinal strain <27.5 % had 59.3 % sensitivity and 79.1 % specificity for the discrimination of INFMI + RVMI from INFMI. Our results demonstrated that right atrial reservoir and conduit functions were impaired in the patients with INFMI + RVMI compared with the patients with INFMI.

  17. Influence of left ventricular dysfunction (diastolic versus systolic) on long-term prognosis in patients with versus without diabetes mellitus having elective peripheral arterial surgery.

    PubMed

    van Kuijk, Jan-Peter; Flu, Willem-Jan; Valentijn, Tabita M; Chonchol, Michel; Kuiper, Ruud J; Verhagen, Hence J M; Bax, Jeroen J; Poldermans, Don

    2010-09-15

    Diabetes mellitus (DM) and left ventricular dysfunction (LVD) are often coexistent and invariably associated with increased mortality. Data on long-term prognosis of "isolated" diastolic LVD in diabetics are lacking; therefore, we evaluated these prognostic implications in patients with peripheral arterial disease (PAD) and DM. Using echocardiography, 1321 patients were screened for diastolic, systolic (ejection fraction <50%) or combined LVD. Diastolic LVD was diagnosed based on the ratio of early rapid filling to late filling due to atrial contraction, pulmonary vein flow, and deceleration time. Patients using glucose-lowering drugs or insulin or with a fasting glucose level >6.1 mmol/L were diagnosed with DM. The primary end point was occurrence of cardiovascular death during a mean follow-up of 2.5 +/- 1.9 years. In the total population, DM was diagnosed in 518 patients (39%), and diastolic, systolic, or combined LVD was present in 356 patients (27%), 102 patients (8%), or 156 patients (12%), respectively. In diabetic patients, diastolic and systolic LVDs were associated with increased cardiovascular mortality (hazard ratio 1.8, 95% confidence interval 1.03 to 3.03; hazard ratio 3.1, 95% confidence interval 1.46 to 6.38). In nondiabetic patients, the same association between diastolic or systolic LVD and outcome was observed (hazard ratio 2.2, 95% confidence interval 1.30 to 3.74; hazard ratio 3.9, 95% confidence interval 2.00 to 7.52). Combined systolic and diastolic LVD had the worst prognosis. In conclusion, diabetic patients with PAD have an increased prevalence of isolated systolic and combined LVD. In patients with PAD the presence of isolated diastolic, systolic, or combined LVD was independently and equally associated with increased cardiovascular mortality, irrespective of the concomitant presence of DM.

  18. Recognition of Fibrotic Infarct Density by the Pattern of Local Systolic-Diastolic Myocardial Electrical Impedance

    PubMed Central

    Amorós-Figueras, Gerard; Jorge, Esther; García-Sánchez, Tomás; Bragós, Ramón; Rosell-Ferrer, Javier; Cinca, Juan

    2016-01-01

    Myocardial electrical impedance is a biophysical property of the heart that is influenced by the intrinsic structural characteristics of the tissue. Therefore, the structural derangements elicited in a chronic myocardial infarction should cause specific changes in the local systolic-diastolic myocardial impedance, but this is not known. This study aimed to characterize the local changes of systolic-diastolic myocardial impedance in a healed myocardial infarction model. Six pigs were successfully submitted to 150 min of left anterior descending (LAD) coronary artery occlusion followed by reperfusion. 4 weeks later, myocardial impedance spectroscopy (1–1000 kHz) was measured at different infarction sites. The electrocardiogram, left ventricular (LV) pressure, LV dP/dt, and aortic blood flow (ABF) were also recorded. A total of 59 LV tissue samples were obtained and histopathological studies were performed to quantify the percentage of fibrosis. Samples were categorized as normal myocardium (<10% fibrosis), heterogeneous scar (10–50%) and dense scar (>50%). Resistivity of normal myocardium depicted phasic changes during the cardiac cycle and its amplitude markedly decreased in dense scar (18 ± 2 Ω·cm vs. 10 ± 1 Ω·cm, at 41 kHz; P < 0.001, respectively). The mean phasic resistivity decreased progressively from normal to heterogeneous and dense scar regions (285 ± 10 Ω·cm, 225 ± 25 Ω·cm, and 162 ± 6 Ω·cm, at 41 kHz; P < 0.001 respectively). Moreover, myocardial resistivity and phase angle correlated significantly with the degree of local fibrosis (resistivity: r = 0.86 at 1 kHz, P < 0.001; phase angle: r = 0.84 at 41 kHz, P < 0.001). Myocardial infarcted regions with greater fibrotic content show lower mean impedance values and more depressed systolic-diastolic dynamic impedance changes. In conclusion, this study reveals that differences in the degree of myocardial fibrosis can be detected in vivo by local measurement of phasic systolic

  19. A Novel Transgenic Mouse Model of Cardiac Hypertrophy and Atrial Fibrillation

    PubMed Central

    Rosenberg, Michael A.; Das, Saumya; Pinzon, Pablo Quintero; Knight, Ashley C.; Sosnovik, David E.; Ellinor, Patrick T.; Rosenzweig, Anthony

    2012-01-01

    Cardiac hypertrophy is a major risk factor for the development of atrial fibrillation (AF). However, there are few animal models of AF associated with cardiac hypertrophy. In this study, we describe the in vivo electrophysiological characteristics and histopathology of a mouse model of cardiac hypertrophy that develops AF. Myostatin is a well-known negative regulator of skeletal muscle growth that was recently found to additionally regulate cardiac muscle growth. Using cardiac-specific expression of the inhibitory myostatin pro-peptide, we generated transgenic (TG) mice with dominant-negative regulation of MSTN (DN-MSTN). One line (DN-MSTN TG13) displayed ventricular hypertrophy, as well as spontaneous AF on the surface electrocardiogram (ECG), and was further evaluated. DN-MSTN TG13 had normal systolic function, but displayed atrial enlargement on cardiac MRI, as well as atrial fibrosis histologically. Baseline ECG revealed an increased P wave duration and QRS interval compared with wild-type littermate (WT) mice. Seven of 19 DN-MSTN TG13 mice had spontaneous or inducible AF, while none of the WT mice had atrial arrhythmias (p<0.05). Connexin40 (Cx40) was decreased in DN-MSTN TG13 mice, even in the absence of AF or significant atrial fibrosis, raising the possibility that MSTN signaling may play a role in Cx40 down-regulation and the development of AF in this mouse model. In conclusion, DN-MSTN TG13 mice represent a novel model of AF, in which molecular changes including an initial loss of Cx40 are noted prior to fibrosis and the development of atrial arrhythmias. PMID:23243484

  20. Efficient algorithm and systolic architecture for modular division

    NASA Astrophysics Data System (ADS)

    Chen, Chuanpeng; Qin, Zhongping

    2011-06-01

    A new efficient modular division algorithm suitable for systolic implementation and its systolic architecture is proposed in this article. With a new exit condition of while loop and a new updating method of a control variable, the new algorithm reduces the average of iteration numbers by more than 14.3% compared to the algorithm proposed by Chen, Bai and Chen. Based on the new algorithm, we design a fast systolic architecture with an optimised core computing cell. Compared to the architecture proposed by Chen, Bai and Chen, our systolic architecture has reduced the critical path delay by about 18% and the total computational time for one modular division by almost 30%, with the cost of about 1% more cells. Moreover, by the addition of a flag signal and three logic gates, the proposed systolic architecture can also perform Montgomery modular multiplication and a fast unified modular divider/multiplier is realised.

  1. The left atrial "Medusa myxoma".

    PubMed

    Williams, Elbert E; Pratt, Jerry W; Martin, David E

    2014-02-01

    Although myxomas are the most commonly seen primary cardiac tumors, encompassing 30% to 50% of all primary tumors of the heart, they remain a rare finding with an annual reported incidence of 0.5 per million. The presenting symptoms of an atrial myxoma are widely varied as are the clinical consequences. Regardless of presentation, once a diagnosis is made prompt surgical excision is recommended to minimize the potential complications of obstruction or embolization. We present the "Medusa myxoma," an arborizing 4-fingered left atrial myxoma extending from the fossa ovalis across the left atrium.

  2. [Panic disorder and atrial fibrillation].

    PubMed

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

    2013-10-01

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

  3. Systolic array IC for genetic computation

    NASA Astrophysics Data System (ADS)

    Anderson, D.

    Measuring similarities between large sequences of genetic information is a formidable task requiring enormous amounts of computer time. Geneticists claim that nearly two months of CRAY-2 time are required to run a single comparison of the known database against the new bases that will be found this year, and more than a CRAY-2 year for next year's genetic discoveries, and so on. The DNA IC, designed at HP-ICBD in cooperation with the California Institute of Technology and the Jet Propulsion Laboratory, is being implemented in order to move the task of genetic comparison onto workstations and personal computers, while vastly improving performance. The chip is a systolic (pumped) array comprised of 16 processors, control logic, and global RAM, totaling 400,000 FETS. At 12 MHz, each chip performs 2.7 billion 16 bit operations per second. Using 35 of these chips in series on one PC board (performing nearly 100 billion operations per second), a sequence of 560 bases can be compared against the eventual total genome of 3 billion bases, in minutes--on a personal computer. While the designed purpose of the DNA chip is for genetic research, other disciplines requiring similarity measurements between strings of 7 bit encoded data could make use of this chip as well. Cryptography and speech recognition are two examples. A mix of full custom design and standard cells, in CMOS34, were used to achieve these goals. Innovative test methods were developed to enhance controllability and observability in the array. This paper describes these techniques as well as the chip's functionality. This chip was designed in the 1989-90 timeframe.

  4. Systolic array IC for genetic computation

    NASA Technical Reports Server (NTRS)

    Anderson, D.

    1991-01-01

    Measuring similarities between large sequences of genetic information is a formidable task requiring enormous amounts of computer time. Geneticists claim that nearly two months of CRAY-2 time are required to run a single comparison of the known database against the new bases that will be found this year, and more than a CRAY-2 year for next year's genetic discoveries, and so on. The DNA IC, designed at HP-ICBD in cooperation with the California Institute of Technology and the Jet Propulsion Laboratory, is being implemented in order to move the task of genetic comparison onto workstations and personal computers, while vastly improving performance. The chip is a systolic (pumped) array comprised of 16 processors, control logic, and global RAM, totaling 400,000 FETS. At 12 MHz, each chip performs 2.7 billion 16 bit operations per second. Using 35 of these chips in series on one PC board (performing nearly 100 billion operations per second), a sequence of 560 bases can be compared against the eventual total genome of 3 billion bases, in minutes--on a personal computer. While the designed purpose of the DNA chip is for genetic research, other disciplines requiring similarity measurements between strings of 7 bit encoded data could make use of this chip as well. Cryptography and speech recognition are two examples. A mix of full custom design and standard cells, in CMOS34, were used to achieve these goals. Innovative test methods were developed to enhance controllability and observability in the array. This paper describes these techniques as well as the chip's functionality. This chip was designed in the 1989-90 timeframe.

  5. Laser Atrial Septostomy: An Engineering Problem

    NASA Astrophysics Data System (ADS)

    Ben-Shachar, Giora; Cohen, Mark H.; Riemenschneider, Thomas A.; Beder, Stanley D.

    1987-04-01

    The purpose of this study was to develop a reproducible method for atrial septostomy in live animals, which would be independent of both atrial septal thickness and left atrial size. Seven mongrel dogs monitored electrocardiographically were anesthetized and instrumented with systemic and pulmonary arterial lines. A modified Mullin's transseptal sheath was advanced under fluoroscopic control to interrogate the left atrium and atrial septum. A 400 micron regular quartz or a laser heated metallic tip fiber was passed through the sheath up to the atrial septum. Lasing of the atrial septum was done with an Argon laser at power output of 5 watts. In three dogs, an atrial septosomy catheter was passed to the left atrium through the laser atrial septostomy and balloon atrial septostomy was performed. The laser atrial septostomy measured 3 x 5 mm in diameter. This interatrial communication could be enlarged with a balloon septostomy to over one cm in diameter. Hemodynamic and electrocardiographic monitoring were stable during the procedure. Engineering problems included: 1) radioluscency of the laser fibers thus preventing fluoroscopic localization of the fiber course; and 2) the inability to increase lateral vaporization of the atrial septum. It is concluded that further changes in the lasing fibers need to be made before the method can be considered for clinical use.

  6. Role of echocardiography in diagnosis and risk stratification in heart failure with left ventricular systolic dysfunction

    PubMed Central

    Ciampi, Quirino; Villari, Bruno

    2007-01-01

    Heart failure (HF) is a complex clinical syndrome that can result from any structural or functional cardiac disorder that impairs the ability of the ventricle to fill with or eject blood. Echocardiography represents the "gold standard" in the assessment of LV systolic dysfunction and in the recognition of systolic heart failure, since dilatation of the LV results in alteration of intracardiac geometry and hemodynamics leading to increased morbidity and mortality. The functional mitral regurgitation is a consequence of adverse LV remodelling that occurs with a structurally normal valve and it is a marker of adverse prognosis. Diastolic dysfunction plays a major role in signs and symptoms of HF and in the risk stratification, and provides prognostic information independently in HF patients and impaired systolic function. Ultrasound lung comets are a simple echographic sign of extravascular lung water, more frequently associated with left ventricular diastolic and/or systolic dysfunction, which can integrate the clinical and pathophysiological information provided by conventional echocardiography and provide a useful information for prognostic stratification of HF patients. Contractile reserve is defined as the difference between values of an index of left ventricular contractility during peak stress and its baseline values and the presence of myocardial viability predicts a favorable outcome. A non-invasive echocardiographic method for the evaluation of force-frequency relationship has been proposed to assess the changes in contractility during stress echo. In conclusion, in HF patients, the evaluation of systolic, diastolic function and myocardial contractile reserve plays a fundamental role in the risk stratification. The highest risk is present in HF patients with a heart that is weak, big, noisy, stiff and wet. PMID:17910744

  7. Role of echocardiography in diagnosis and risk stratification in heart failure with left ventricular systolic dysfunction.

    PubMed

    Ciampi, Quirino; Villari, Bruno

    2007-10-02

    Heart failure (HF) is a complex clinical syndrome that can result from any structural or functional cardiac disorder that impairs the ability of the ventricle to fill with or eject blood. Echocardiography represents the "gold standard" in the assessment of LV systolic dysfunction and in the recognition of systolic heart failure, since dilatation of the LV results in alteration of intracardiac geometry and hemodynamics leading to increased morbidity and mortality. The functional mitral regurgitation is a consequence of adverse LV remodelling that occurs with a structurally normal valve and it is a marker of adverse prognosis. Diastolic dysfunction plays a major role in signs and symptoms of HF and in the risk stratification, and provides prognostic information independently in HF patients and impaired systolic function. Ultrasound lung comets are a simple echographic sign of extravascular lung water, more frequently associated with left ventricular diastolic and/or systolic dysfunction, which can integrate the clinical and pathophysiological information provided by conventional echocardiography and provide a useful information for prognostic stratification of HF patients. Contractile reserve is defined as the difference between values of an index of left ventricular contractility during peak stress and its baseline values and the presence of myocardial viability predicts a favorable outcome. A non-invasive echocardiographic method for the evaluation of force-frequency relationship has been proposed to assess the changes in contractility during stress echo. In conclusion, in HF patients, the evaluation of systolic, diastolic function and myocardial contractile reserve plays a fundamental role in the risk stratification. The highest risk is present in HF patients with a heart that is weak, big, noisy, stiff and wet.

  8. Inflammation and oxidative stress caused by nitric oxide synthase uncoupling might lead to left ventricular diastolic and systolic dysfunction in patients with hypertension

    PubMed Central

    Szelényi, Zsuzsanna; Fazakas, Ádám; Szénási, Gábor; Kiss, Melinda; Tegze, Narcis; Fekete, Bertalan Csaba; Nagy, Eszter; Bodó, Imre; Nagy, Bálint; Molvarec, Attila; Patócs, Attila; Pepó, Lilla; Prohászka, Zoltán; Vereckei, András

    2015-01-01

    Objective To investigate the role of oxidative stress, inflammation, hypercoagulability and neuroendocrine activation in the transition of hypertensive heart disease to heart failure with preserved ejection fraction (HFPEF). Methods We performed echocardiography for 112 patients (≥ 60 years old) with normal EF (18 controls and 94 with hypertension), and determined protein carbonylation (PC), and tetrahydrobiopterin (BH4), C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), fibrinogen, plasminogen activator inhibitor type-I (PAI-I), von Willebrand factor, chromogranin A (cGA) and B-type natriuretic peptide (BNP) levels from their blood samples. Results We found that 40% (38/94) of the patients with hypertension (HT) had no diastolic dysfunction (HTDD−), and 60% (56/94) had diastolic dysfunction (HTDD+). Compared to the controls, both patient groups had increased PC and BH4, TNF-α, PAI-I and BNP levels, while the HTDD+ group had elevated cGA and CRP levels. Decreased atrial and longitudinal left ventricular (LV) systolic and diastolic myocardial deformation (strain and strain rate) was demonstrated in both patient groups versus the control. Patients whose LV diastolic function deteriorated during the follow-up had elevated PC and IL-6 level compared to their own baseline values, and to the respective values of patients whose LV diastolic function remained unchanged. Oxidative stress, inflammation, BNP and PAI-I levels inversely correlated with LV systolic, diastolic and atrial function. Conclusions In patients with HT and normal EF, the most common HFPEF precursor condition, oxidative stress and inflammation may be responsible for LV systolic, diastolic and atrial dysfunction, which are important determinants of the transition of HT to HFPEF. PMID:25678898

  9. End-systolic pressure-volume relationship and intracellular control of contraction.

    PubMed

    Landesberg, A

    1996-01-01

    The left ventricular (LV) pressure-volume relationship and the effect of ejection on pressure generation are predicted theoretically based on the intracellular control mechanisms. The control of contraction is described based on coupling calcium kinetics and cross-bridge cycling. The analysis of published skinned and intact cardiac muscle data suggests two feedback control loops: 1) a positive cooperative mechanism that determines the force-length relationship, the length dependence calcium sensitivity of the contractile filaments, and the related Frank Starling law; and 2) a negative mechanical feedback that determines the force-velocity relationship and the generated power. The interplay between these two feedback mechanisms explains the wide spectrum of phenomena associated with the end-systolic pressure-volume relationship (ESPVR); it provides an explanation for the "shortening deactivation" and for the recent observations of the positive effect of ejection on the ESPVR, i.e., the increase of the end-systolic pressure of the ejecting beat over the pressure of the isovolumic beat at the same end-systolic volume. Furthermore, the analysis suggests that the LV contractility depends on the balance between the two intracellular mechanisms and that the effect of loading conditions is determined through these intracellular mechanisms.

  10. Masked Hypertension and Left Atrial Dysfunction: A Hidden Association.

    PubMed

    Tadic, Marijana; Cuspidi, Cesare; Radojkovic, Jana; Rihor, Branislav; Kocijanic, Vesna; Celic, Vera

    2017-03-01

    Masked hypertension (MH) is a clinical condition that indicates normal values of clinic blood pressure (BP) but elevated 24-hour BP. The purpose of this study was to investigate the relationship between MH and left atrial (LA) phasic function evaluated by both the volumetric and speckle tracking method. This cross-sectional study included 49 normotensive individuals, 50 patients with MH, and 70 untreated sustained hypertensive patients adjusted by age and sex. MH was diagnosed if clinic BP was normal and 24-hour BP was increased. LA reservoir function was lower in patients with MH and those with sustained hypertension compared with the normotensive group. LA conduit function gradually decreased, while LA booster pump function progressively increased, from normotension to sustained hypertension. Similar results were obtained by two-dimensional echocardiographic strain analysis. Independently of main clinic and echocardiographic characteristics, 24-hour systolic BP was associated with LA passive ejection fraction, LA total longitudinal strain, LA positive longitudinal strain, and LA stiffness index. In conclusion, MH is associated with impairment of LA phasic function and stiffness, and 24-hour systolic BP increment was closely related with LA remodeling.

  11. Facts about Atrial Septal Defect

    MedlinePlus

    ... Developmental Disabilities) be credited and notified in any public or private usage of this image. Close × Atrial Septal Defect The images are ... Developmental Disabilities) be credited and notified in any public or private usage of this image. Close Information For... ... Makers Language: English ...

  12. Echocardiographic Assessment of Pulmonary Artery Systolic Pressure and Outcomes in Ambulatory Heart Failure Patients

    PubMed Central

    Kalogeropoulos, Andreas P.; Siwamogsatham, Sarawut; Hayek, Salim; Li, Song; Deka, Anjan; Marti, Catherine N.; Georgiopoulou, Vasiliki V.; Butler, Javed

    2014-01-01

    Background Pulmonary hypertension (PH) in patients with heart failure (HF) is associated with worse outcomes and is rapidly being recognized as a therapeutic target. To facilitate pragmatic research efforts, data regarding the prognostic importance of noninvasively assessed pulmonary artery systolic pressure (PASP) in stable ambulatory patients with HF are needed. Methods and Results We examined the association between echocardiographic PASP and outcomes in 417 outpatients with HF (age, 54±13 years; 60.7% men; 50.4% whites; 24.9% with preserved ejection fraction). Median PASP was 36 mm Hg (interquartile range [IQR]: 29, 46). After a median follow‐up of 2.6 years (IQR: 1.7, 3.9) there were 72 major events (57 deaths; 9 urgent heart transplants; and 6 ventricular assist device implantations) and 431 hospitalizations for HF. In models adjusting for clinical risk factors and therapy, a 10‐mm Hg higher PASP was associated with 37% higher risk (95% CI: 18, 59; P<0.001) for major events, and 11% higher risk (95% CI: 1, 23; P=0.039) for major events or HF hospitalization. The threshold that maximized the likelihood ratio for both endpoints was 48 mm Hg; those with PASP ≥48 mm Hg (N=84; 20.1%) had an adjusted hazard ratio of 3.33 (95% CI: 1.96, 5.65; P<0.001) for major events and 1.47 (95% CI: 1.02, 2.11; P=0.037) for major events or HF hospitalization. Reduced right ventricular systolic function had independent prognostic utility over PASP for adverse outcomes. Right atrial pressure and transtricuspid gradient both contributed to risk. Conclusions Elevated PASP, determined by echocardiography, identifies ambulatory patients with HF at increased risk for adverse events. PMID:24492947

  13. [Atrial fibrillation and cognitive function].

    PubMed

    Duron, Emmanuelle; Hanon, Olivier

    2010-09-01

    Atrial fibrillation (AF), which prevalence increases with age, is a growing public health problem and a well known risk factor for stroke. On the other hand, dementia is one of the most important neurological disorders in the elderly, and with aging of the population in developed countries, the number of demented patients will increase in absence of prevention. In the past decade, several vascular risk factors (hypertension, obesity and metabolic syndrome, hypercholesterolemia) have been found, with various degree of evidence, to be associated with vascular dementia but also, surprisingly, with Alzheimer's disease. This review is devoted to the links between atrial fibrillation, cognitive decline and dementia. Globally, transversal studies showed a significant association between atrial fibrillation, cognitive decline and dementia. However, these studies are particularly sensitive to various biases. In this context, recent longitudinal studies of higher level of evidence have been conducted to assess the link between AF and dementia. One study disclosed a high incidence of dementia among patients suffering from atrial fibrillation during a 4.6 years follow-up. Similarly another study showed that atrial fibrillation was significantly associated with conversion from mild cognitive impairment to dementia during a 3 years follow-up. Nevertheless two other longitudinal studies did not find any significant association between AF and dementia, but this discrepancy should be interpreted taking into account that the comparability of all these studies is moderate because they were using different methodologies (population, cognitive testing, and mean follow-up). Possible explanatory mechanisms for the association between AF and the risk of dementia are proposed, such as thrombo-embolic ischemic damage and cerebral hypo perfusion due to fluctuations in the cardiac output. Thus, there is some evidence that FA could be associated with cognitive decline and dementia but this

  14. Association of SNP Rs9943582 in APLNR with Left Ventricle Systolic Dysfunction in Patients with Coronary Artery Disease in a Chinese Han GeneID Population

    PubMed Central

    Wang, Chuchu; Wu, Yanxia; Wang, Dan; Chen, Shanshan; Zhao, Yuanyuan; Wang, Xiaojing; Li, Sisi; Yang, Qin; Zeng, Qiutang; Tu, Xin; Liao, Yuhua; Wang, Qing K.; Cheng, Xiang

    2015-01-01

    Heart failure affects 1–2% of the adult population worldwide and coronary artery disease (CAD) is the underlying etiology of heart failure in 70% of the patients. The pathway of apelin and its apelin receptor (APJ) was implicated in the pathogenesis of heart failure in animal models, but a similar role in humans is unknown. We studied a functional variant, rs9943582 (-154G/A), at the 5’-untranslated region, that was associated with decreased expression of the APJ receptor gene (APLNR) in a population consisting of 1,751 CAD cases and 1,022 controls. Variant rs9943582 was not associated with CAD, but among CAD patients, it showed significant association with left ventricular systolic dysfunction (431 CAD patients with left ventricular systolic dysfunction (LV ejection fraction or LVEF< 40%) versus 1,046 CAD patients without LV systolic dysfunction (LVEF>50%) (P-adj = 6.71×10-5, OR = 1.43, 95% CI, 1.20–1.70). Moreover, rs9943582 also showed significant association with quantitative echocardiographic parameters, including left ventricular end-diastolic diameter (effect size: increased 1.67±0.43 mm per risk allele A, P = 1.15×10-4), left atrial size (effect size: increased 2.12±0.61 mm per risk allele A, P = 9.56×10-4) and LVEF (effect size: decreased 2.59±0.32 percent per risk allele A, P = 7.50×10-15). Our findings demonstrate that allele A of rs9943582 was significantly associated with left ventricular systolic dysfunction, left ventricular end-diastolic diameter, the left atrial diameter and LVEF in the CAD population, which suggests an important role of the apelin/APJ system in the pathology of heart failure associated with ischemic heart disease. PMID:25993436

  15. The impact of end-diastolic and end-systolic phase selection in the volumetric evaluation of cardiac MRI

    PubMed Central

    Contijoch, Francisco; Witschey, Walter RT; Rogers, Kelly; Gorman, Joseph; Gorman, Robert C; Ferrari, Victor; Han, Yuchi

    2015-01-01

    Purpose To evaluate the impact of end-diastolic (ED) and end-systolic (ES) cardiac phase selection methods since task force recommendation have neither provided quantitative evidence nor explored errors introduced by clinical shortcuts. Materials and Methods Multi-slice, short-axis cine images were collected in 60 clinical patients on a 1.5T scanner. User-initialized active contour segmentation software quantified global left ventricular (LV) volume across all cardiac phases. Different approaches for selection of (ED) and (ES) phase were evaluated by quantification of temporal and volumetric errors. Results For diastole, the mid-ventricular maximum slice volume coincided with maximum global volume in 82.1% of patients with ejection fraction (EF) ≥ 55% (p = 0.66) and 71.9% of patients with EF <55% (p = 0.28) and is an accurate approximation of maximum global volume while the first and last phases in a retrospectively ECG-gated acquisition introduced differences in cardiac phase selection (p < 0.001) which led to large errors in measured volume in some patients (12.7 and 10.1 mL, respectively). For systole, post-systolic shortening occured in a significantly higher number of patients with EF < 55% (18.9%) compared to 3.6% of patients with EF ≥ 55% (p = 0.001), which differentially impacted end-systolic volume estimation. Conclusion For end-diastolic phase selection, our results indicated that the use of the mid-ventricular slice volume maximum provided accurate volume estimates while selection of the first or last cardiac phase introduced differences in measured volume. For end-systolic phase, patients with EF < 55% had a higher prevalence of post-systolic shortening which suggests aortic valve closure should be used to estimate end-systolic volume. PMID:26331591

  16. In Vitro System for Measuring Chordal Force Changes Following Mitral Valve Patch Repair

    PubMed Central

    Ostli, B; Vester-Petersen, J; Askov, JB; Honge, JL; Levine, RA; Hagège, A; Nielsen, SL; Hasenkam, JM; Nygaard, H; Jensen, MO

    2013-01-01

    Background Attention towards optimization of mitral valve repair methods is increasing. Patch augmentation is one strategy utilized to correct functional mitral regurgitation or systolic anterior motion in complex mitral valve repairs. This article describes a system for investigating the redistribution of chordae tendineae tension as a reflection of altered stress distribution of the valve leaflet following patch augmentation. Methods and materials An in vitro test setup was constructed to hold native porcine mitral valves containing an annulus and papillary muscle positioning system. The alterations caused by patch augmentation should be visual from both the atrial and ventricular views. Ventricular pressure was regulated stepwise in a range of 0-150 mmHg. To test the system, the anterior mitral leaflet was extended by a pericardial patch sutured to the mid/basal part of the leaflet, and the chordae tendineae force was measured as the ventricular pressure was applied. Results The system demonstrated the capacity to hold native porcine mitral valves and introducing patch repairs according to clinical practice. The porcine mitral valve test setup indicated strong correlation between the forces in the mitral valve secondary chordae tendineae and the applied transvalvular pressure (R2 = 0.95). Conclusion This test setup proved the ability to obtain normal mid-systolic mitral valve function, secondary chordae force measurements, and important preservation of the visual access: Hence, obtaining the pressure-force relationship as well as identifying any shift of the secondary chordae insertion point on the anterior leaflet relative to the coaptation zone was made possible. PMID:26273417

  17. What Are the Signs and Symptoms of Atrial Fibrillation?

    MedlinePlus

    ... What Are the Signs and Symptoms of Atrial Fibrillation? Atrial fibrillation (AF) usually causes the heart's lower ... pain Dizziness or fainting Fatigue (tiredness) Confusion Atrial Fibrillation Complications AF has two major complications— stroke and ...

  18. Present treatment options for atrial fibrillation

    PubMed Central

    Lairikyengbam, S; Anderson, M; Davies, A

    2003-01-01

    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 treatment is not. This article will discuss how rhythm control of atrial fibrillation can best be achieved, the controversy over the rhythm versus rate control, the maintenance of sinus rhythm with antiarrhythmic drugs after cardioversion, and prevention of thromboembolism. Finally, the recent advances in various non-pharmacological approaches for the treatment of atrial fibrillation will be highlighted. PMID:12612318

  19. [Prophylaxis of thromboembolism in atrial fibrillation: new oral anticoagulants and left atrial appendage closure].

    PubMed

    Zeus, Tobias; Kelm, Malte; Bode, Christoph

    2015-08-01

    Thrombo-embolic prophylaxis is a key element within the therapy of atrial fibrillation/atrial flutter. Besides new oral anticoagulants the concept of left atrial appendage occlusion has approved to be a good alternative option, especially in patients with increased risk of bleeding.

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

    PubMed Central

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

    2015-01-01

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

  1. Almanac 2015: atrial fibrillation research in Heart

    PubMed Central

    Jawad-Ul-Qamar, Muhammad; Kirchhof, Paulus

    2016-01-01

    Atrial fibrillation continues to attract interest in the cardiovascular community and in Heart. Over 60 original research and review papers published in Heart in 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 in Heart in 2014–2015, highlighting new developments, emerging concepts and novel approaches to treatment. PMID:26791994

  2. Left Atrial Appendage Closure Devices

    PubMed Central

    Romero, Jorge; Perez, Irving E; Krumerman, Andrew; Garcia, Mario J; Lucariello, Richard J

    2014-01-01

    Atrial fibrillation (AF) increases the risk for thromboembolic stroke five-fold. The left atrial appendage (LAA) has been shown to be the main source of thrombus formation in the majority of strokes associated with AF. Oral anticoagulation with warfarin and novel anticoagulants remains the standard of care; however, it has several limitations, including bleeding and poor compliance. Occlusion of the LAA has been shown to be an alternative therapeutic approach to drug therapy. The purpose of this article is to review the different techniques and devices that have emerged for the purpose of occluding this structure, with a particular emphasis on the efficacy and safety studies published to date in the medical literature. PMID:24963274

  3. Timing and magnitude of systolic stretch affect myofilament activation and mechanical work

    PubMed Central

    Tangney, Jared R.; Campbell, Stuart G.; McCulloch, Andrew D.

    2014-01-01

    Dyssynchronous activation of the heart leads to abnormal regional systolic stretch. In vivo studies have suggested that the timing of systolic stretch can affect regional tension and external work development. In the present study, we measured the direct effects of systolic stretch timing on the magnitude of tension and external work development in isolated murine right ventricular papillary muscles. A servomotor was used to impose precisely timed stretches relative to electrical activation while a force transducer measured force output and strain was monitored using a charge-couple device camera and topical markers. Stretches taking place during peak intracellular Ca2+ statistically increased peak tension up to 270%, whereas external work due to stretches in this interval reached values of 500 J/m. An experimental analysis showed that time-varying elastance overestimated peak tension by 100% for stretches occurring after peak isometric tension. The addition of the force-velocity relation explained some effects of stretches occurring before the peak of the Ca2+ transient but had no effect in later stretches. An estimate of transient deactivation was measured by performing quick stretches to dissociate cross-bridges. The timing of transient deactivation explained the remaining differences between the model and experiment. These results suggest that stretch near the start of cardiac tension development substantially increases twitch tension and mechanical work production, whereas late stretches decrease external work. While the increased work can mostly be explained by the time-varying elastance of cardiac muscle, the decreased work in muscles stretched after the peak of the Ca2+ transient is largely due to myofilament deactivation. PMID:24878774

  4. Assessment of atrial electromechanical interval using echocardiography after catheter ablation in patients with persistent atrial fibrillation

    PubMed Central

    Chen, Xiaodong; Chen, Minglong; Wang, Yingying; Yang, Bing; Ju, Weizhu; Zhang, Fengxiang; Cao, Kejiang

    2016-01-01

    Abstract We sought to investigate variation of atrial electromechanical interval after catheter ablation procedure in patients with persistent atrial fibrillation using pulse Doppler (PW) and pulse tissue Doppler imaging (PW-TDI). A total of 25 consecutive in-patients with persistent atrial fibrillation, who restored sinus rhythm after ablation procedure, were recruited in our cardiac center. Echocardiography was performed on each patient at 2 hours, 1 day, 5 days, 1 month and 3 months after the ablation therapy, and atrial electromechanical delay was measured simultaneously by PW and PW-TDI. There was no significant difference between PW and TDI in measuring atrial electromechanical delay. However, at postoperative 2 hours, peak A detection rates were mathematically but nonsignificantly greater by PW-TDI than by PW. Second, there was a significant decreasing trend in atrial electromechanical interval from postoperative 2 hours to 3 months, but only postoperative 2-hour atrial electromechanical interval was significantly greater than atrial electromechanical interval at other time. Lastly, patients without postoperative 2-hour atrial electromechanical interval had a significantly longer duration of atrial fibrillation as compared to those with postoperative 2-hour atrial electromechanical interval, by the PW or by PW-TDI, respectively. In patients with persistent atrial fibrillation, atrial electromechanical interval may decrease significantly within the first 24 hours after ablation but remain consistent later, and was significantly related to patients’ duration of atrial fibrillation. Atrial electromechanical interval, as a potential predicted factor, is recommended to be measured by either PW or TDI after 24 hours, when patients had recovered sinus rhythm by radiofrequency ablation. PMID:27924066

  5. Association of left atrial reservoir function with left atrial structural remodeling related to left ventricular dysfunction in asymptomatic patients with hypertension: evaluation by two-dimensional speckle-tracking echocardiography.

    PubMed

    Miyoshi, Hirokazu; Oishi, Yoshifumi; Mizuguchi, Yukio; Iuchi, Arata; Nagase, Norio; Ara, Nusrat; Oki, Takashi

    2015-01-01

    Left atrial (LA) structural and functional abnormalities are vital steps on the pathway toward heart failure with preserved ejection fraction in asymptomatic patients. The purpose of this study was to assess the relationship of LA function, particularly reservoir function, with LA structural remodeling related to the left ventricular (LV) dysfunction in asymptomatic patients with hypertension (HT) using conventional, tissue Doppler, and 2-D speckle-tracking echocardiography. Fifty age-matched healthy individuals and 140 patients with HT, including 75 with LA volume index (LAVI)<29 ml/m2 (normal LA group) and 65 with LAVI≥29 ml/m2 (large LA group), were enrolled. We defined peak early diastolic transmitral flow velocity/peak early diastolic mitral annular motion velocity (E/e')/peak systolic LA strain (S-LAs) as LA diastolic stiffness. The LV mass index, relative LV wall thickness, peak atrial systolic transmitral flow velocity, LA total, active, and passive emptying volume indexes, and E/e'/S-LAs were greatest, and S-LAs, peak early diastolic LA strain, peak systolic LV longitudinal strain and circumferential strain rate, and peak early diastolic LV radial strain rate were lower in the large LA group compared with control and/or normal LA group. Multivariate linear regression analysis revealed that aging, LA remodeling, and LV systolic and diastolic dysfunction are defined as strong predictors related to increased LA diastolic stiffness in the large LA group. HT alters LA dynamics significantly, with resultant increased LA volume and diastolic stiffness related to LV diastolic and systolic dysfunction, even in asymptomatic patients. Earlier treatment with renin–angiotensin system inhibitors may improve abnormal LA-LV interaction in this patient population.

  6. Genetics and genomics of dilated cardiomyopathy and systolic heart failure.

    PubMed

    Tayal, Upasana; Prasad, Sanjay; Cook, Stuart A

    2017-02-22

    Heart failure is a major health burden, affecting 40 million people globally. One of the main causes of systolic heart failure is dilated cardiomyopathy (DCM), the leading global indication for heart transplantation. Our understanding of the genetic basis of both DCM and systolic heart failure has improved in recent years with the application of next-generation sequencing and genome-wide association studies (GWAS). This has enabled rapid sequencing at scale, leading to the discovery of many novel rare variants in DCM and of common variants in both systolic heart failure and DCM. Identifying rare and common genetic variants contributing to systolic heart failure has been challenging given its diverse and multiple etiologies. DCM, however, although rarer, is a reasonably specific and well-defined condition, leading to the identification of many rare genetic variants. Truncating variants in titin represent the single largest genetic cause of DCM. Here, we review the progress and challenges in the detection of rare and common variants in DCM and systolic heart failure, and the particular challenges in accurate and informed variant interpretation, and in understanding the effects of these variants. We also discuss how our increasing genetic knowledge is changing clinical management. Harnessing genetic data and translating it to improve risk stratification and the development of novel therapeutics represents a major challenge and unmet critical need for patients with heart failure and their families.

  7. Invasively Measured Aortic Systolic Blood Pressure and Office Systolic Blood Pressure in Cardiovascular Risk Assessment: A Prospective Cohort Study.

    PubMed

    Laugesen, Esben; Knudsen, Søren T; Hansen, Klavs W; Rossen, Niklas B; Jensen, Lisette Okkels; Hansen, Michael G; Munkholm, Henrik; Thomsen, Kristian K; Søndergaard, Hanne; Bøttcher, Morten; Raungaard, Bent; Madsen, Morten; Hulman, Adam; Witte, Daniel; Bøtker, Hans Erik; Poulsen, Per L

    2016-09-01

    Aortic systolic blood pressure (BP) represents the hemodynamic cardiac and cerebral burden more directly than office systolic BP. Whether invasively measured aortic systolic BP confers additional prognostic value beyond office BP remains debated. In this study, office systolic BP and invasively measured aortic systolic BP were recorded in 21 908 patients (mean age: 63 years; 58% men; 14% with diabetes mellitus) with stable angina pectoris undergoing elective coronary angiography during January 2001 to December 2012. Multivariate Cox models were used to assess the association with incident myocardial infarction, stroke, and death. Discrimination and reclassification were assessed using Harrell's C and the Continuous Net Reclassification Index. Data were analyzed with and without stratification by diabetes mellitus status. During a median follow-up period of 3.7 years (range: 0.1-10.8 years), 422 strokes, 511 myocardial infarctions, and 1530 deaths occurred. Both office and aortic systolic BP were associated with stroke in patients with diabetes mellitus (hazard ratio per 10 mm Hg, 1.18 [95% confidence interval, 1.07-1.30] and 1.14 [95% confidence interval, 1.05-1.24], respectively) and with myocardial infarction in patients without diabetes mellitus (hazard ratio, 1.07 [95% confidence interval, 1.02-1.12] and 1.05 [95% confidence interval, 1.01-1.10], respectively). In models including both BP measurements, aortic BP lost statistical significance and aortic BP did not confer improvement in either C-statistics or net reclassification analysis. In conclusion, invasively measured aortic systolic BP does not add prognostic information about cardiovascular outcomes and all-cause mortality compared with office BP in patients with stable angina pectoris, either with or without diabetes mellitus.

  8. Application of Mitral Annular Systolic Displacements and Velocities for the Evaluation of Left Ventricular Systolic Function and Reserve

    PubMed Central

    Sharif, Dawod; Sharif-Rasslan, Amal; Shahla, Camilia; Rosenschein, Uri

    2011-01-01

    Background Mitral annular systolic displacement from M-mode echocardiography and velocity from tissue Doppler imaging reflect subendocardial longitudinal systolic LV performance and may precede radial abnormalities. The aim of this study is to evaluate the utility of mitral annular systolic displacement (D) and velocity (V) during dobutamine stress echocardiography (DSE) in detecting left ventricular (LV) functional reserve and wall motion abnormality (WMA). Methods and Results Fifty-nine subjects, 15 with resting WMA, underwent DSE and measurement of mitral systolic (D) and (V) before and immediately after DSE. Annular septal (D) was lower in those with WMA than in those without, at rest 10.5 ± 4 cm versus 13.2 ± 2 cm, p = 0.015, and after DSE, 11.7 ± 3.8 cm versus 14 ± 2.25 cm, p = 0.036, but without significant change after stress. Annular systolic (V) at rest with WMA was 9.7 ± 1.8 cm/sec and similar to those without, 11.25 ± 2.7 cm/sec. In both groups the velocity increased after DSE, 14.5 ± 4.5 cm/sec, p = 0.025 with WMA and 17.8 ± 3.2 cm/sec, p = 1.99 x 10-10 in those without WMA. Velocities after DSE were lower in those with WMA, p = 2.25 x 10-6. Conclusions To evaluate LV systolic performance mitral annular systolic longitudinal displacement is valuable at rest, but for assessment of LV functional reserve after stress velocities are better.

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

    PubMed

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

    2015-07-01

    The causal relationship between atrial and ventricular activities during human atrial fibrillation (AF) is poorly understood. This study analyzed the effects of an increase in atrial rate on the link between atrial and ventricular activities during AF. Atrial and ventricular time series were determined in 14 patients during the spontaneous acceleration of the atrial rhythm at AF onset. The dynamic relationship between atrial and ventricular activities was quantified in terms of atrioventricular (AV) coupling by AV synchrogram analysis. The technique identified n:m coupling patterns (n atrial beats in m ventricular cycles), quantifying their percentage, maximal length, and conduction ratio (= m/n). Simulations with a difference-equation AV model were performed to correlate the observed dynamics to specific atrial/nodal properties. The atrial rate increase significantly affected AV coupling and ventricular response during AF. The shortening of atrial intervals from 185 ± 32 to 165 ± 24 ms (P < 0.001) determined transitions toward AV patterns with progressively decreasing m/n ratios (from conduction ratio = 0.34 ± 0.09 to 0.29 ± 0.08, P < 0.01), lower occurrence (from percentage of coupled beats = 27.1 ± 8.0 to 21.8 ± 6.9%, P < 0.05), and higher instability (from maximal length = 3.9 ± 1.5 to 2.8 ± 0.7 s, P < 0.01). Advanced levels of AV block and coupling instability at higher atrial rates were associated with increased ventricular interval variability (from 123 ± 52 to 133 ± 55 ms, P < 0.05). AV pattern transitions and coupling instability in patients were predicted, assuming the filtering of high-rate irregular atrial beats by the slow recovery of nodal excitability. These results support the role of atrial rate in determining AV coupling and ventricular response and may have implications for rate control in AF.

  10. Tricuspid annular plane systolic excursion and pulmonary arterial systolic pressure relationship in heart failure: an index of right ventricular contractile function and prognosis.

    PubMed

    Guazzi, M; Bandera, F; Pelissero, G; Castelvecchio, S; Menicanti, L; Ghio, S; Temporelli, P L; Arena, R

    2013-11-01

    Echo-derived pulmonary arterial systolic pressure (PASP) and right ventricular (RV) tricuspid annular plane systolic excursion (TAPSE; from the end of diastole to end-systole) are of basic relevance in the clinical follow-up of heart failure (HF) patients, carrying two- to threefold increase in cardiac risk when increased and reduced, respectively. We hypothesized that the relationship between TAPSE (longitudinal RV fiber shortening) and PASP (force generated by the RV) provides an index of in vivo RV length-force relationship, with their ratio better disclosing prognosis. Two hundred ninety-three HF patients with reduced (HFrEF, n = 247) or with preserved left ventricular (LV) ejection fraction (HFpEF, n = 46) underwent echo-Doppler studies and N-terminal pro-brain-type natriuretic peptide assessment and were tracked for adverse events. The median follow-up duration was 20.8 mo. TAPSE vs. PASP relationship showed a downward regression line shift in nonsurvivors who were more frequently presenting with higher PASP and lower TAPSE. HFrEF and HFpEF patients exhibited a similar distribution along the regression line. Given the TAPSE, PASP, and TAPSE-to-PASP ratio (TAPSE/PASP) collinearity, separate Cox regression and Kaplan-Meier analyses were performed: one with TAPSE and PASP as individual measures, and the other combining them in ratio form. Hazard ratios for variables retained in the multivariate regression were as follows: TAPSE/PASP force relationship may be a step forward for a more efficient RV function evaluation and

  11. Atrial Arrhythmia Summit: Post Summit Report

    NASA Technical Reports Server (NTRS)

    Barr, Yael

    2010-01-01

    The Atrial Arrhythmia Summit brought together nationally and internationally recognized experts in cardiology, electrophysiology, exercise physiology, and space medicine in an effort to elucidate the mechanisms, risk factors, and management of atrial arrhythmias in the unique occupational cohort of the U.S. astronaut corps.

  12. Left atrial myxoma masquerading as viral flu

    PubMed Central

    Chhabra, Lovely; Kiernan, Francis

    2016-01-01

    Atrial myxoma is a rare cardiac tumor that may be diagnosed incidentally on cardiac imaging or may present with life-threatening cardiac symptoms. We present a case of giant left atrial myxoma that presented as a flulike illness. PMID:27695187

  13. Giant right atrial thrombi treated with thrombolysis.

    PubMed

    Ruiz-Bailén, Manuel; López-Caler, Carmen; Castillo-Rivera, Ana; Rucabado-Aguilar, Luis; Ramos Cuadra, José Angel; Lara Toral, Juan; Lozano Cabezas, Cristobal; Fernández Guerrero, Juan Carlos

    2008-04-01

    The present report describes giant atrial thrombi that were treated with thrombolysis in a community hospital. Two patients with giant atrial thrombi whose treatment involved complications are presented. Both patients developed cardiogenic shock and were treated unsuccessfully with thrombolysis. Because thrombolysis of giant thrombi may be ineffective, patients in this situation may require surgery.

  14. Giant right atrial thrombi treated with thrombolysis

    PubMed Central

    Ruiz-Bailén, Manuel; López-Caler, Carmen; Castillo-Rivera, Ana; Rucabado-Aguilar, Luis; Cuadra, José Ángel Ramos; Toral, Juan Lara; Cabezas, Cristobal Lozano; Guerrero, Juan Carlos Fernández

    2008-01-01

    The present report describes giant atrial thrombi that were treated with thrombolysis in a community hospital. Two patients with giant atrial thrombi whose treatment involved complications are presented. Both patients developed cardiogenic shock and were treated unsuccessfully with thrombolysis. Because thrombolysis of giant thrombi may be ineffective, patients in this situation may require surgery. PMID:18401474

  15. A novel and simple atrial retractor.

    PubMed

    Kofidis, Theo; Lee, Chuen Neng

    2011-05-01

    Minimally invasive cardiac operations require specialized equipment. Atrial retractors are a frequently used tool to expose heart valves for minimally invasive and open procedures. The models currently available in the market are efficient; however, they may be complex, bulky, or expensive. We introduce a novel, very simple atrial retractor we designed using ubiquitously available materials.

  16. Who Is at Risk for Atrial Fibrillation?

    MedlinePlus

    ... at Risk for Atrial Fibrillation? Atrial fibrillation (AF) affects millions of people, and the number is rising. Men are more ... conditions. It may act as a trigger in people who have other AF risk factors. Genetic factors also may play a role in causing AF. However, their role ... SITE INDEX ACCESSIBILITY PRIVACY STATEMENT FOIA OIG CONTACT ...

  17. Is there a synergic effect of propafenone associated with atrial overdrive pacing for atrial arrhythmia prevention? A randomised crossover study

    PubMed Central

    Garrigue, S; Barold, S; Cazeau, S; Hocini, M; Jais, P; Haissaguerre, M; Clementy, J

    2000-01-01

    OBJECTIVE—To assess the effect of adding propafenone to atrial overdrive for the prevention of atrial arrhythmia episodes in patients with DDD pacemakers.
DESIGN—22 patients (8 female, 14 male, mean (SD) age 67 (9) years, range 48 to 77) with DDD pacemakers and frequent paroxysmal atrial arrhythmia episodes were evaluated in a randomised crossover study.
SETTING—University hospital.
METHODS—Atrial overdrive was defined as a paced rate of 10 paced beats/min above the mean ventricular rate stored for the last 24 hours in the pacemaker memory function. The protocol consisted of two phases of one month each. The first phase consisted of atrial overdrive alone, while in the second phase, propafenone (600 mg/day) was added to atrial overdrive (atrial overdrive + propafenone). All 22 patients underwent the two phases in random order.
RESULTS—Mean ventricular rate was 72 (8) beats/min with atrial overdrive v 73 (6) with atrial overdrive + propafenone (NS). With atrial overdrive, 14 patients (64.6%) had no recorded atrial arrhythmia v 15 (68.2%) with atrial overdrive + propafenone (NS). There was no statistical difference between the atrial overdrive and atrial overdrive + propafenone phases with regard to the number of atrial arrhythmia episodes (14 (27) v 13 (28)), their total duration (30 (78) v 29 (63) h), and their maximum duration (41 (72) v 31 (58) min). However, in the brady-tachy subgroup with persistent atrial arrhythmias, atrial overdrive + propafenone produced a shorter mean cumulative duration of atrial arrhythmia than atrial overdrive (104 (115) v 178 (149) h, p = 0.04), with a significant decrease in the number of atrial arrhythmia episodes (134 (98) v 102 (83), p = 0.05). The proportion of asymptomatic atrial arrhythmia episodes increased only in the AV block group during atrial overdrive + propafenone (p = 0.03). Three patients had atrial arrhythmias during atrial overdrive + propafenone but not

  18. Evaluation of Right Ventricular Myocardial Mechanics using Velocity Vector Imaging of Cardiac MRI Cine Images in Transposition of the Great Arteries Following Atrial and Arterial Switch Operations

    PubMed Central

    Thattaliyath, Bijoy D.; Forsha, Daniel E.; Stewart, Chad; Barker, Piers C.A.; Campbell, Michael J.

    2016-01-01

    Objective The aim of the study was to determine right and left ventricle deformation parameters in patients with transposition of the great arteries who had undergone atrial or arterial switch procedures. Setting Patients with transposition are born with a systemic right ventricle. Historically, the atrial switch operation, in which the right ventricle remains the systemic ventricle, was performed. These patients have increased rates of morbidity and mortality. We used cardiac MRI with Velocity Vector Imaging analysis to characterize and compare ventricular myocardial deformation in patients who had an atrial switch or arterial switch operation. Design Patients with a history of these procedures, who had a clinically ordered cardiac MRI were included in the study. Consecutive 20 patients (75% males, 28.7±1.8 years) who underwent atrial switch operation and 20 patients (60% males, 17.7±1.9 years) who underwent arterial switch operation were included in the study. Four chamber and short-axis cine images were used to determine longitudinal and circumferential strain and strain rate using Vector Velocity Imaging software. Results Compared to the arterial switch group, the atrial switch group had decreased right ventricular ejection fraction and increased end-diastolic and end-systolic volumes; and no difference in left ventricular ejection fraction and volumes. The atrial switch group had decreased longitudinal and circumferential strain and strain rate. When compared to normal controls multiple strain parameters in the atrial switch group were reduced. Conclusions Myocardial deformation analysis of transposition patients reveals a reduction of right ventricular function and decreased longitudinal and circumferential strain parameters in patients with an atrial switch operation compared to those with arterial switch operation. A better understanding of the mechanisms of RV failure in TGA may lead to improved therapies and adaptation. PMID:25655213

  19. FFT Computation with Systolic Arrays, A New Architecture

    NASA Technical Reports Server (NTRS)

    Boriakoff, Valentin

    1994-01-01

    The use of the Cooley-Tukey algorithm for computing the l-d FFT lends itself to a particular matrix factorization which suggests direct implementation by linearly-connected systolic arrays. Here we present a new systolic architecture that embodies this algorithm. This implementation requires a smaller number of processors and a smaller number of memory cells than other recent implementations, as well as having all the advantages of systolic arrays. For the implementation of the decimation-in-frequency case, word-serial data input allows continuous real-time operation without the need of a serial-to-parallel conversion device. No control or data stream switching is necessary. Computer simulation of this architecture was done in the context of a 1024 point DFT with a fixed point processor, and CMOS processor implementation has started.

  20. The molecular and functional identities of atrial cardiomyocytes in health and disease.

    PubMed

    Brandenburg, Sören; Arakel, Eric C; Schwappach, Blanche; Lehnart, Stephan E

    2016-07-01

    Atrial cardiomyocytes are essential for fluid homeostasis, ventricular filling, and survival, yet their cell biology and physiology are incompletely understood. It has become clear that the cell fate of atrial cardiomyocytes depends significantly on transcription programs that might control thousands of differentially expressed genes. Atrial muscle membranes propagate action potentials and activate myofilament force generation, producing overall faster contractions than ventricular muscles. While atria-specific excitation and contractility depend critically on intracellular Ca(2+) signalling, voltage-dependent L-type Ca(2+) channels and ryanodine receptor Ca(2+) release channels are each expressed at high levels similar to ventricles. However, intracellular Ca(2+) transients in atrial cardiomyocytes are markedly heterogeneous and fundamentally different from ventricular cardiomyocytes. In addition, differential atria-specific K(+) channel expression and trafficking confer unique electrophysiological and metabolic properties. Because diseased atria have the propensity to perpetuate fast arrhythmias, we discuss our understanding about the cell-specific mechanisms that lead to metabolic and/or mitochondrial dysfunction in atrial fibrillation. Interestingly, recent work identified potential atria-specific mechanisms that lead to early contractile dysfunction and metabolic remodelling, suggesting highly interdependent metabolic, electrical, and contractile pathomechanisms. Hence, the objective of this review is to provide an integrated model of atrial cardiomyocytes, from tissue-specific cell properties, intracellular metabolism, and excitation-contraction (EC) coupling to early pathological changes, in particular metabolic dysfunction and tissue remodelling due to atrial fibrillation and aging. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes

  1. Low Power Systolic Array Based Digital Filter for DSP Applications

    PubMed Central

    Karthick, S.; Valarmathy, S.; Prabhu, E.

    2015-01-01

    Main concepts in DSP include filtering, averaging, modulating, and correlating the signals in digital form to estimate characteristic parameter of a signal into a desirable form. This paper presents a brief concept of low power datapath impact for Digital Signal Processing (DSP) based biomedical application. Systolic array based digital filter used in signal processing of electrocardiogram analysis is presented with datapath architectural innovations in low power consumption perspective. Implementation was done with ASIC design methodology using TSMC 65 nm technological library node. The proposed systolic array filter has reduced leakage power up to 8.5% than the existing filter architectures. PMID:25922854

  2. Systolic time interval data acquisition system. Specialized cardiovascular studies

    NASA Technical Reports Server (NTRS)

    Baker, J. T.

    1976-01-01

    The development of a data acquisition system for noninvasive measurement of systolic time intervals is described. R-R interval from the ECG determines instantaneous heart rate prior to the beat to be measured. Total electromechanical systole (Q-S2) is measured from the onset of the ECG Q-wave to the onset of the second heart sound (S2). Ejection time (ET or LVET) is measured from the onset of carotid upstroke to the incisure. Pre-ejection period (PEP) is computed by subtracting ET from Q-S2. PEP/ET ratio is computed directly.

  3. Low Power Systolic Array Based Digital Filter for DSP Applications.

    PubMed

    Karthick, S; Valarmathy, S; Prabhu, E

    2015-01-01

    Main concepts in DSP include filtering, averaging, modulating, and correlating the signals in digital form to estimate characteristic parameter of a signal into a desirable form. This paper presents a brief concept of low power datapath impact for Digital Signal Processing (DSP) based biomedical application. Systolic array based digital filter used in signal processing of electrocardiogram analysis is presented with datapath architectural innovations in low power consumption perspective. Implementation was done with ASIC design methodology using TSMC 65 nm technological library node. The proposed systolic array filter has reduced leakage power up to 8.5% than the existing filter architectures.

  4. Coexistence of abnormal systolic motion of mitral valve in a consecutive group of 324 adult Tetralogy of Fallot patients assessed with echocardiography

    PubMed Central

    Agarwal, Anushree; Harris, Ian S; Mahadevan, Vaikom S; Foster, Elyse

    2016-01-01

    Background The presence of mitral valve prolapse (MVP) in congenital heart disease (CHD) patients is not well described. Tetralogy of Fallot (TOF) is the most common cyanotic CHD associated with overall good long-term survival after palliation. Since MVP is more often identified in adults and TOF patients are now surviving longer, we thus sought to perform this cohort study with a case–control design to (1) determine the prevalence of MVP and systolic displacement of mitral leaflets (SDML) in adult TOF patients, and (2) describe their clinical and imaging characteristics. Methods Retrospective interrogation of our echocardiography database identified 328 consecutive TOF patients ≥18 years from 1 January 2000 to 31 December 2014. All images were reviewed to identify patients with concomitant MVP (prolapse >2 mm beyond the long-axis annular plane) or SDML (<2 mm beyond the annular plane). Results 26 (8%) TOF patients fulfilled criteria for systolic mitral valve abnormality (SMVA) (15 MVP; 11 SDML). 2 had moderate to severe mitral regurgitation requiring repair. When compared with 52 TOF patients without SMVA, those with SMVA were more likely to be females (60.7% vs 33.9%, p=0.03), less likely to have transannular patch (52% vs 97.4%, p<0.0001), had lower right ventricular ejection fraction (36.5% vs 43.8%, p=0.03) and a trend towards increased risk of atrial (44% vs 30.4%, p=0.5) and ventricular arrhythmias (32% vs 25.5%, p=0.6). On multivariate logistic regression, SMVA was independently associated with the absence of transannular patch (p=0.002) and atrial arrhythmias (p=0.04). Conclusions In this series of adult TOF patients, we describe a novel finding of a high prevalence of systolic mitral valve abnormalities. PMID:28123759

  5. Association of CHADS2 and CHA2DS2-VASc Scores with Left Atrial Thrombus with Nonvalvular Atrial Fibrillation: A Single Center Based Retrospective Study in a Cohort of 2695 Chinese Subjects

    PubMed Central

    Huang, J.; Xue, YM.; Fei, HW.; Lin, QW.; Ren, SQ.; Liao, HT.; Zhan, XZ.; Fang, XH.; Xu, L.

    2017-01-01

    The main mechanism of the CHADS2 and CHA2DS2-VASc scores to predict stroke in nonvalvular atrial fibrillation (NVAF) is still controversial. We evaluated the association of the CHADS2 and CHA2DS2-VASc scores with left atrial thrombus (LAT) as detected by transesophageal echocardiographic (TEE) and compared the predictive ability of these risk stratification schemes with nonvalvular atrial fibrillation (NVAF). Data from 2,695 consecutive NVAF patients in whom TEE was performed for screening LAT from July 2007 to February 2014 were analyzed. Only 3% of the subjects had LAT. Presence of LAT was not significantly associated with either CHADS2  (P = 0.07) or CHA2DS2-VASc score (P = 0.12). The area under the curve (AUC) concerning LAT prediction using CHADS2 and CHA2DS2-VASc was 0.574 and 0.569, respectively. A composition model includes previous stroke or transient ischemic attack, nonparoxysmal AF, moderate to severe left ventricular systolic dysfunction, left atrial enlargement, and cardiomyopathy which improved the discrimination significantly (AUC = 0.743). In our cohort, both CHADS2 and CHA2DS2-VASc scores were of limited value for predicting LAT in patients with NVAF. This questions the CHADS2/CHA2DS2-VASc score predicting stroke mainly through the mechanism of cardiogenic embolism. A scoring scheme combining clinical and echocardiographic parameters may better predict LAT as a surrogate for cardioembolic risk in NVAF patients. PMID:28373985

  6. [Stroke. are there any difference between patients with or without patent foramen ovale in left atrial appendage systolic function?].

    PubMed

    Contreras, Alejandro E; Perrote, Federico; Concari, Ignacio; Brenna, Eduardo J; Lucero, Cecilia

    2012-01-01

    Introducción: El objetivo del presente trabajo fue comparar la función sistólica de la orejuela de la aurícula izquierda (OAI) en un grupo de pacientes con y sin foramen oval permeable (FOP) quienes sufrieron eventos cerebrovasculares isquémicos. Material y métodos: Entre septiembre de 2010 y octubre de 2011, 17 pacientes fueron enviados para la realización de un ecocardiograma transesofágico (ETE) por haber sufrido un accidente cerebrovascular (ACV). Se definió FOP al pasaje de al menos una burbuja a través del septum interauricular con test de burbujas. Se comparó la velocidad sistólica en la orejuela entre los pacientes con y sin FOP y con un grupo control. Resultados: Fueron 8 mujeres y 9 hombres, con una edad media de 54,1 ± 19,5 años. Todos los pacientes habían sufrido un evento cerebrovascular isquémico, el 41,2% habían tenido ACV, el 52,9% crisis isquémica transitoria y el 5,9% amaurosis fugaz. En la evaluación con ETE, el 11,8% tuvo aneurisma del septum interauricular y el 35,3% FOP. La velocidad sistólica media de la OAI fue 66,3 ± 20,3 cm/seg. No hubo diferencia en la velocidad sistólica de la OAI entre pacientes con o sin FOP (67,5 ± 11,8 cm/seg vs 65,7 ± 24,3 cm/seg respectivamente, p= 0,87). El grupo control compuesto por 8 pacientes, 5 mujeres y 3 hombres, con una edad media de 39,5 ± 18 años, tuvo una velocidad sistólica de la OAI de 77,6 ± 28,9 cm/seg, sin diferencias significativas con los pacientes isquémicos. Conclusión: No hubo diferencias en la función sistólica de la OAI entre pacientes con y sin FOP con eventos cerebrovasculares isquemicos.

  7. Non-Alcoholic Fatty Liver Disease as a Predictor of Atrial Fibrillation in Middle-Aged Population (OPERA Study).

    PubMed

    Käräjämäki, Aki J; Pätsi, Olli-Pekka; Savolainen, Markku; Kesäniemi, Y Antero; Huikuri, Heikki; Ukkola, Olavi

    2015-01-01

    Non-alcoholic fatty liver disease (NAFLD) and atrial fibrillation (AF) are widespread diseases and have multiple common risk factors and comorbidities. No studies of association between ultrasonography-diagnosed NAFLD and AF exist in other than diabetic population. The goal of this prospective study was to study the value of NAFLD as a predictor of atrial fibrillation. This study had 958 subjects from the OPERA (Oulu Project Elucidating Risk of Atherosclerosis) cohort, and the mean follow-up time was 16.3 years. NAFLD was diagnosed if the subject had fatty liver in ultrasonography and no excess alcohol intake. AF was followed in the National Registers. In this study 249 subjects (26.0%) had NAFLD and 37 (14.9%) of these had AF whereas only 56 (7.9%) of those without NAFLD experienced AF during the follow-up time (p = 0.001). In the multiple Cox regression analysis including potential confounders (age, sex, study group, diabetes, body mass index (BMI), waist circumference, alcohol consumption, smoking, serum alanine aminotransferase concentration (ALT), systolic blood pressure, quick index, left ventricular mass index, left atrial diameter, coronary artery disease (CAD), atrial natriuretic peptide (ANP) and high sensitive C-reactive protein (hs-CRP)), NAFLD remained as an independent predictor of AF (Adjusted OR, 1.88 (95% Confidence interval (CI) 1.03-3.45)). In conclusion, our data shows that NAFLD is independently associated with the risk of AF.

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

    PubMed

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

    2015-10-01

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

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

    PubMed Central

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

    2015-01-01

    Cardiac tamponade resulting from perforation of a cardiac chamber is a relatively rare complication of pacemaker implantation. We report the first case of perforation of the right coronary artery related to the implantation of a screw-in atrial pacing lead, presenting as life-threatening cardiac tamponade. We report the case of a 72-year-old woman with complete atrioventricular block and dyspnea on exertion. A permanent pacemaker was implanted with bipolar Medtronic active-fixation leads positioned in the right atrial appendage and at the right ventricular basal septum without any difficulty. Approximately 3.5 h after the procedure, the patient complained of nausea, and the systolic blood pressure decreased to less than 60 mmHg. Echocardiography revealed a large pericardial effusion. Because the effects of pericardiocentesis lasted for less than an hour, the patient underwent a thoracotomy. After evacuation of a massive hemopericardium, bright red blood was seen gushing out from the right coronary artery, which was located on the opposite site of the right atrial appendage where a small portion of the screw tip was observed to be penetrating the atrial wall. The right coronary artery perforation was repaired using autologous pericardium-reinforced 7-0 prolene mattress sutures. Perforation of the right coronary artery is a potential complication and should be part of the differential diagnosis of cardiac tamponade after pacemaker implantation. PMID:26550089

  10. Mapping technique for VLSI/WSI implementation of multidimensional systolic arrays

    NASA Astrophysics Data System (ADS)

    Abdelrazik, Mohamed B.

    1990-09-01

    This paper describes a niapping technique for transforming a linear systolic array into multidimensional systolic arrays in order to achieve high-speed with less overhead. This technique is systematic therefore it would be useful for logic synthesis. The application of this technique in DSP and numerical computations reduces the design time which results in low design cost. This technique produces various structures (semi-systolic quasi-systolic and pure systolic arrays) which could be considered as application specific array processors.

  11. 4D flow MRI assessment of right atrial flow patterns in the normal heart – influence of caval vein arrangement and implications for the patent foramen ovale

    PubMed Central

    Parikh, Jehill D.; Kakarla, Jayant; Keavney, Bernard; O’Sullivan, John J.; Ford, Gary A.; Blamire, Andrew M.; Hollingsworth, Kieren G.

    2017-01-01

    Aim To investigate atrial flow patterns in the normal adult heart, to explore whether caval vein arrangement and patency of the foramen ovale (PFO) may be associated with flow pattern. Materials and Methods Time-resolved, three-dimensional velocity encoded magnetic resonance imaging (4D flow) was employed to assess atrial flow patterns in thirteen healthy subjects (6 male, 40 years, range 25–50) and thirteen subjects (6 male, 40 years, range 21–50) with cryptogenic stroke and patent foramen ovale (CS-PFO). Right atrial flow was defined as vortical, helico-vortical, helical and multiple vortices. Time-averaged and peak systolic and diastolic flows in the caval and pulmonary veins and their anatomical arrangement were compared. Results A spectrum of right atrial flow was observed across the four defined categories. The right atrial flow patterns were strongly associated with the relative position of the caval veins. Right atrial flow patterns other than vortical were more common (p = 0.015) and the separation between the superior and inferior vena cava greater (10±5mm versus 3±3mm, p = 0.002) in the CS-PFO group. In the left atrium all subjects except one had counter-clockwise vortical flow. Vortex size varied and was associated with left lower pulmonary vein flow (systolic r = 0.61, p = 0.001, diastolic r = 0.63 p = 0.002). A diastolic vortex was less common and time-averaged left atrial velocity was greater in the CS-PFO group (17±2cm/sec versus 15±1, p = 0.048). One CS-PFO subject demonstrated vortical retrograde flow in the descending aortic arch; all other subjects had laminar descending aortic flow. Conclusion Right atrial flow patterns in the normal heart are heterogeneous and are associated with the relative position of the caval veins. Patterns, other than ‘typical’ vortical flow, are more prevalent in the right atrium of those with cryptogenic stroke in the context of PFO. Left atrial flow patterns are more homogenous in normal hearts and show a

  12. Platelet activation of mechanical versus bioprosthetic heart valves during systole.

    PubMed

    Hedayat, Mohammadali; Asgharzadeh, Hafez; Borazjani, Iman

    2017-03-11

    Thrombus formation is a major concern for recipients of mechanical heart valves (MHVs), which requires them to take anticoagulant drugs for the rest of their lives. Bioprosthetic heart valves (BHVs) do not require life-long anticoagulant therapy but deteriorate after 10-15years. The thrombus formation is initiated by the platelet activation which is thought to be mainly generated in MHVs by the flow through the hinge and the leakage flow during the diastole. However, our results show that the activation in the bulk flow during the systole phase might play an essential role as well. This is based on our results obtained by comparing the thrombogenic performance of a MHV and a BHV (as control) in terms of shear induced platelet activation under exactly the same conditions. Three different mathematical activation models including linear level of activation, damage accumulation, and Soares model are tested to quantify the platelet activation during systole using the previous simulations of the flow through MHV and BHV in a straight aorta under the same physiologic flow conditions. Results indicate that the platelet activation in the MHV at the beginning of the systole phase is slightly less than the BHV. However, at the end of the systole phase the platelet activation by the bulk flow for the MHV is several folds (1.41, 5.12, and 2.81 for linear level of activation, damage accumulation, and Soares model, respectively) higher than the BHV for all tested platelet activation models.

  13. Automatic noninvasive measurement of systolic blood pressure using photoplethysmography

    PubMed Central

    Nitzan, Meir; Patron, Amikam; Glik, Zehava; Weiss, Abraham T

    2009-01-01

    Background Automatic measurement of arterial blood pressure is important, but the available commercial automatic blood pressure meters, mostly based on oscillometry, are of low accuracy. Methods In this study, we present a cuff-based technique for automatic measurement of systolic blood pressure, based on photoplethysmographic signals measured simultaneously in fingers of both hands. After inflating the pressure cuff to a level above systolic blood pressure in a relatively slow rate, it is slowly deflated. The cuff pressure for which the photoplethysmographic signal reappeared during the deflation of the pressure-cuff was taken as the systolic blood pressure. The algorithm for the detection of the photoplethysmographic signal involves: (1) determination of the time-segments in which the photoplethysmographic signal distal to the cuff is expected to appear, utilizing the photoplethysmographic signal in the free hand, and (2) discrimination between random fluctuations and photoplethysmographic pattern. The detected pulses in the time-segments were identified as photoplethysmographic pulses if they met two criteria, based on the pulse waveform and on the correlation between the signal in each segment and the signal in the two neighboring segments. Results Comparison of the photoplethysmographic-based automatic technique to sphygmomanometry, the reference standard, shows that the standard deviation of their differences was 3.7 mmHg. For subjects with systolic blood pressure above 130 mmHg the standard deviation was even lower, 2.9 mmHg. These values are much lower than the 8 mmHg value imposed by AAMI standard for automatic blood pressure meters. Conclusion The photoplethysmographic-based technique for automatic measurement of systolic blood pressure, and the algorithm which was presented in this study, seems to be accurate. PMID:19857254

  14. [Secondary pulmonary embolism to right atrial myxoma].

    PubMed

    Vico Besó, L; Zúñiga Cedó, E

    2013-10-01

    A case of pulmonary thromboembolism secondary to atrial myxoma right. The myxoma is a primary cardiac tumor, namely, has his origin in the cardiac tissue. Primary cardiac tumors are rare, including myxomas, the most common type. Have a predilection for females and the most useful tool for diagnosis is echocardiography. About 75% of myxomas occur in the left atrium of the heart and rest are in the right atrium. Right atrial myxomas in some sometimes associated with tricuspid stenosis and atrial fibrillation. The most common clinical manifestations include symptoms of this neoplasm constitutional, and embolic phenomena resulting from the obstruction to the flow intracavitary. The treatment of this condition is surgical.

  15. Effect of NIP-142 on potassium channel alpha-subunits Kv1.5, Kv4.2 and Kv4.3, and mouse atrial repolarization.

    PubMed

    Tanaka, Hikaru; Namekata, Iyuki; Hamaguchi, Shogo; Kawamura, Taro; Masuda, Hiroyuki; Tanaka, Yoshio; Iida-Tanaka, Naoko; Takahara, Akira

    2010-01-01

    Effects of NIP-142, a benzopyran compound which terminates experimental atrial arrhythmia, on potassium channel alpha-subunits and mouse atrial repolarization were examined. NIP-142 concentration-dependently blocked the outward current through potassium channel alpha subunits Kv1.5, Kv4.2 and Kv4.3 expressed in Xenopus oocytes. In isolated mouse atrial myocardia, NIP-142 prolonged the action potential duration and effective refractory period, and increased the contractile force. These results suggest that NIP-142 blocks the potassium channels underlying the transient and sustained outward currents, which may contribute to its antiarrhythmic activity.

  16. Chronic Alternate Day Fasting Results in Reduced Diastolic Compliance and Diminished Systolic Reserve in Rats

    PubMed Central

    Ahmet, Ismayil; Wan, Ruiqian; Mattson, Mark P; Lakatta, Edward G.; Talan, Mark I.

    2010-01-01

    Background Based on animal experiments and limited data from few human trials, alternate day fasting (ADF) resulted in weight loss; prolonged life; reduced metabolic risk factors for diabetes and cardiovascular diseases; and reduced prevalence of age-related diseases. The present study is the first comprehensive examination of the long-term effects of ADF on general cardiovascular fitness in rats. Methods and Results Four months old male Sprague-Dawley rats were started on ADF or continued on ad libitum diets and followed for 6 months with serial echocardiography. A comprehensive hemodynamic evaluation including a combined dobutamine - volume stress test was performed at the end of the study, and hearts were harvested for histological assessment. The six-month long ADF diet resulted in a 9% reduction (p<0.01) of cardiomyocyte diameter and 3 fold increase in interstitial myocardial fibrosis. Left ventricular chamber size was not affected by ADF and ejection fraction was not reduced, but left atrial diameter was increased 16%, and the E/A in Doppler-measured mitral flow was reduced (p<0.01). Pressure-volume loop analyses revealed a “stiff” heart during diastole in ADF rats, while combined dobutamine and volume loading showed a significant reduction in LV diastolic compliance and a lack of increase in systolic pump function, indicating a diminished cardiac reserve. Conclusion Chronic ADF in rats results in development of diastolic dysfunction with diminished cardiac reserve. ADF is a novel and unique experimental model of diet-induced diastolic dysfunction. The deleterious effect of ADF in rats suggests that additional studies of ADF effects on cardiovascular functions in humans are warranted. PMID:20932467

  17. A comparison of systolic blood pressure measurement obtained using a pulse oximeter, and direct systolic pressure measurement in anesthetized sows.

    PubMed Central

    Caulkett, N A; Duke, T; Bailey, J V

    1994-01-01

    Systolic blood pressure measurement obtained with a pulse oximeter has been compared to values obtained by other indirect methods in man. Direct pressure measurement is subject to less error than indirect techniques. This study was designed to compare systolic pressure values obtained using a pulse oximeter, with values obtained by direct arterial pressure measurement. The pulse oximeter waveform was used as an indication of perfusion. A blood pressure cuff was applied proximal to the pulse oximeter probe. The cuff was inflated until the oximeter waveform disappeared, this value was recorded as the systolic pressure at the disappearance of the waveform (SPD). The cuff was inflated to a pressure > 200 mmHg, then gradually deflated until the waveform reappeared, this value was recorded as the systolic pressure at reappearance of the waveform (SPR). The average of the two values, SPD and SPR, was calculated and recorded as SPA. The study was performed in sows (n = 21) undergoing cesarean section under epidural anesthesia and IV sedation. A total of 280 measurements were made of SPD, SPR and SPA. Regression analysis of SPA and direct measurement revealed a correlation coefficient (r) of 0.81. Calculation of mean difference (bias) and standard deviation of the bias (precision) for direct pressure--SPA revealed a value of 1.3 +/- 12.1. When compared with direct measurement, the correlation of this technique was similar to that recorded for other indirect techniques used in small animals. This indicates that this technique would be useful for following systolic pressure trends.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8004540

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

    SciTech Connect

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

    1981-03-01

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

  19. Towards Low Energy Atrial Defibrillation.

    PubMed

    Walsh, Philip; Kodoth, Vivek; McEneaney, David; Rodrigues, Paola; Velasquez, Jose; Waterman, Niall; Escalona, Omar

    2015-09-03

    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. Efficient

  20. Towards Low Energy Atrial Defibrillation

    PubMed Central

    Walsh, Philip; Kodoth, Vivek; McEneaney, David; Rodrigues, Paola; Velasquez, Jose; Waterman, Niall; Escalona, Omar

    2015-01-01

    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 intracardiacimpedance (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. Efficient

  1. Evaluation of a Prediction Model for the Development of Atrial Fibrillation in a Repository of Electronic Medical Records

    PubMed Central

    Kolek, Matthew J.; Graves, Amy J.; Xu, Meng; Bian, Aihua; Teixeira, Pedro Luis; Shoemaker, M. Benjamin; Parvez, Babar; Xu, Hua; Heckbert, Susan R.; Ellinor, Patrick T.; Benjamin, Emelia J.; Alonso, Alvaro; Denny, Joshua C.; Moons, Karel G.M.; Shintani, Ayumi K.; Harrell, Frank E.; Roden, Dan M.; Darbar, Dawood

    2017-01-01

    Importance Atrial fibrillation contributes to substantial morbidity, mortality, and healthcare expenditures. Accurate prediction of incident atrial fibrillation would enhance patient management and potentially improve outcomes. Objective We aimed to validate the atrial fibrillation risk prediction model originally developed by the CHARGE-AF investigators utilizing a large repository of electronic medical records. Design Using a database of de-identified medical records, we conducted a retrospective electronic medical record study of subjects without atrial fibrillation followed in Internal Medicine outpatient clinics at our institution. Individuals were followed for incident atrial fibrillation from 2005 until 2010. Adjusting for differences in baseline hazard, we applied the CHARGE-AF Cox proportional hazards model regression coefficients to our cohort. A simple version of the model, with no ECG variables was also evaluated. Setting Outpatient clinics at a large academic medical center. Participants 33,494 subjects of age ≥40 years, white or African American, and no previous history of atrial fibrillation. Predictors Predictors in the model included age, race, height, weight, systolic and diastolic blood pressure, treatment for hypertension, smoking status, diabetes, heart failure, history of myocardial infarction, left ventricular hypertrophy, and PR interval. Main outcome Incident atrial fibrillation. Results The median age was 57 years (25th to 75th percentile: 49 to 67), 57% of patients were women, 85.7% were white, 14.3% were African American. During the mean follow-up period of 4.8 ± 0.85 years, 2455 (7.3%) subjects developed atrial fibrillation. Both models had poor calibration in our cohort, with under-prediction of AF among low-risk subjects and over-prediction of AF among high-risk subjects. The full CHARGE-AF model had a C-index of 0.71 (95% confidence interval [CI]: 0.70 to 0.72) in our cohort. The simple model had similar discrimination (C-index: 0

  2. Role of angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, and aldosterone antagonists in the prevention of atrial and ventricular arrhythmias.

    PubMed

    Makkar, Kathy M; Sanoski, Cynthia A; Spinler, Sarah A

    2009-01-01

    Atrial arrhythmias, ventricular arrhythmias, and sudden cardiac death (SCD) are significant health problems and an economic burden to society. The renin-angiotensin-aldosterone system (RAAS) may play a key role in the occurrence of structural and electrical remodeling, potentially explaining the development of atrial and ventricular arrhythmias. Angiotensin II has been shown to regulate cardiac cell proliferation and to modulate cardiac myocyte ion channels. Results of post hoc analyses from prospective clinical trials appear to show that angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) are most effective in the prevention of new-onset atrial fibrillation in patients with heart failure. It is difficult to determine if these agents are useful in the prevention of new-onset atrial fibrillation after myocardial infarction, and available evidence suggests that the benefit of ACE inhibitors and ARBs for prevention of new-onset atrial fibrillation in patients with hypertension appears limited to those with left ventricular hypertrophy. Patients with structural changes in cardiac muscle, such as those with heart failure and left ventricular hypertrophy, appear to benefit the most from RAAS blockade, possibly due to the theory of reversal of cardiac remodeling. There is no evidence, to our knowledge, that either ACE inhibitors or ARBs facilitate direct electrical current cardioversion in patients with atrial fibrillation; however, it appears that RAAS blockade may be useful in the prevention of recurrent atrial fibrillation after direct electrical current cardioversion. Whether ACE inhibitors may prevent life-threatening ventricular arrhythmias or SCD is unclear. Aldosterone antagonists appear to be useful for the prevention of SCD in patients with left ventricular systolic dysfunction. Results from ongoing clinical trials are anticipated to provide further insight on the potential roles of RAAS inhibitors for the prevention of

  3. Atrial flutter a manifestation of cardiac tamponade.

    PubMed

    Pabón, Guillermo Mora; Ramírez, John A

    2012-04-01

    Atrial flutter (AFL) is a common arrhythmia that is associated with postpericardiotomy and pericarditis. The relationship of AFL with tamponade has rarely been reported. A case of AFL with acute pericarditis and cardiac tamponade is thus presented here.

  4. Atrial fibrillation in elderly: particularities of management.

    PubMed

    Alexa, Ioana Dana; Bucur, Ionela Mirela; Rusu, R I; Ungureanu, G

    2009-01-01

    Atrial fibrillation (AF), a common and serious cardiac rhythm disturbance, is responsible for substantial morbidity and mortality in the population. Currently about 2.3 million people in the US are diagnosed with AF and, based of the US census, this number is expected to rise to 5.6 million by 2050. It doubles in prevalence with each decade of age, reaching almost 9% at age 80-89 years. It has increased in prevalence over the calendar decades, reaching 'epidemic' proportions. 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 treatment is not. We aimed to discuss how rhythm control of atrial fibrillation can best be achieved in elderly patients, the controversy over the rhythm versus rate control, and prevention of thromboembolism.

  5. Atrial Fibrillation During an Exploration Class Mission

    NASA Technical Reports Server (NTRS)

    Lipsett, Mark; Hamilton, Douglas; Lemery, Jay; Polk, James

    2011-01-01

    This slide presentation reviews a possible scenario of an astronaut having Atrial Fibrillation during a Mars Mission. In the case review the presentation asks several questions about the alternatives for treatment, medications and the ramifications of the decisions.

  6. Atrial conduction delay predicts atrial fibrillation in paroxysmal supraventricular tachycardia patients after radiofrequency catheter ablation.

    PubMed

    Xu, Zhen-Xing; Zhong, Jing-Quan; Zhang, Wei; Yue, Xin; Rong, Bing; Zhu, Qing; Zheng, Zhaotong; Zhang, Yun

    2014-06-01

    This study aimed to assess whether intra- and inter-atrial conduction delay could predict atrial fibrillation (AF) for paroxysmal supraventricular tachycardia (PSVT) patients after successful treatment by radiofrequency catheter ablation (RFCA). Echocardiography examination was performed on 524 consecutive PSVT patients (15 patients were excluded). Left atrial dimension, right atrial diameter and intra- and inter-atrial conduction delay were measured before ablation. Patients were divided into group A (n = 32): occurrence of AF after the ablation and group B (n = 477): remained in sinus rhythm during follow-up. Receiver operating characteristic (ROC) curve analysis was performed to estimate the predictive value of intra- and inter-atrial conduction delay. Both intra- and inter-atrial conduction delay were higher in group A than in group B (4.79 ± 0.30 msec vs. 4.56 ± 0.32 msec; 21.98 ± 1.32 msec vs. 20.01 ± 1.33; p < 0.05). Binary logistic regression analysis showed that intra- and inter-atrial conduction were significant influential factors for the occurrence of AF (odds ratio [OR] = 13.577, 95% confidence interval [CI], 3.469-48.914; OR = 2.569, 95% CI, 1.909-3.459, p < 0.05). The ROC cure analysis revealed that intra-atrial conduction delay ≥ 4.45 msec and inter-atrial conduction delay ≥ 20.65 were the most optimal cut-off value for predicting AF in PSVT patients after RFCA. In conclusion, this is the first study to show that the intra- and inter-atrial conduction delay could effectively predict AF in post-ablation PSVT patients.

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

    PubMed

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

    2012-02-01

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

  8. [Anticoagulation in atrial fibrillation - an update].

    PubMed

    Antz, Matthias; Hullmann, Bettina; Neufert, Christian; Vocke, Wolfgang

    2008-12-01

    The correct anticoagulation regimen for prevention of thromboembolic events is essential in patients with atrial fibrillation. However, only a minority of patients receives anticoagulation according to the guidelines. The current guidelines are intended to make the indication for anticoagulation more simple and are summarized in the present article. This includes recommendations for chronic anticoagulation, prevention of thromboembolic events after cardioversion and in ablation of atrial fibrillation.

  9. Arterial embolism in thyrotoxicosis with atrial fibrillation.

    PubMed Central

    Staffurth, J S; Gibberd, M C; Fui, S N

    1977-01-01

    In 262 patients with thyrotoxicosis and atrial fibrillation there were 26 episodes of arterial embolism (17 cerebral and nine elsewhere) in 21 patients. Twelve incidents occurred with active thyrotoxicosis, three on reversion to sinus rhythm, and 11 after the patients were euthyroid. This important complication is more common than is realised, and most patients should be put on prophylactic anticoagulants when first seen with atrial fibrillation. PMID:902055

  10. Atrial fibrillation cardioversion following acupuncture

    PubMed Central

    Dilber, Dario; Čerkez-Habek, Jasna; Barić, Hrvoje; Gradišer, Marina

    2015-01-01

    Atrial fibrillation (AF) is the most common arrhythmia and it is an independent risk for serious events. Acupuncture has been growing in popularity in the West, and there are reports of its benefits in treating AF. We report a 57-year-old man who was admitted after having an allergic reaction to amiodarone administered to treat paroxysmal AF with fast ventricular response. Cardioversion with intravenous propafenone was uneventful. Before an attempt of electric cardioversion, he was treated with acupuncture as additional therapy to peroral propafenone. After acupuncture treatment consisting of 10 treatments during 30 days period, both immediate cardioversion to sinus rhythm and no paroxysmal AF during 30 days period were recorded. PMID:26593171

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

    NASA Astrophysics Data System (ADS)

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

    2016-11-01

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

  12. Antithrombotic treatment of atrial fibrillation: new insights.

    PubMed

    Le Heuzey, J Y

    2012-10-01

    The incidence and prevalence of atrial fibrillation are quickly increasing, mainly due to the ageing of the population. Atrial fibrillation is, to date, a problem of public health. Atrial fibrillation is associated to a five-fold risk of stroke, which may be identified by score risks, such as CHADS(2) score. The classical antithrombotic treatment of atrial fibrillation is based on vitamin K antagonists. Trials made in the 90's have clearly shown that vitamin K antagonists were able to decrease stroke risk by about 60%. New oral anticoagulants are now available on the market to treat patients with atrial fibrillation. These drugs are dabigatran which has demonstrated an interest in the RE-LY trial. Two doses may be prescribed, 110 mg bid and 150 mg bid. Anti Xa have also demonstrated an interest : rivaroxaban in the ROCKET AF trial and apixaban in the AVERROES (versus aspirin) and ARISTOTLE trials. In the future these drugs will have a major place in the armamentarium used to treat patients with atrial fibrillation. In all these trials a decrease in intra cranial haemorrhages has been demonstrated. In the everyday practice it will be necessary to be very cautious in patients with impaired renal function, as all these drugs are eliminated by kidneys.

  13. Effects of Sacubitril/Valsartan Versus Olmesartan on Central Hemodynamics in the Elderly With Systolic Hypertension: The PARAMETER Study.

    PubMed

    Williams, Bryan; Cockcroft, John R; Kario, Kazuomi; Zappe, Dion H; Brunel, Patrick C; Wang, Qian; Guo, Weinong

    2017-03-01

    Effective treatment of systolic hypertension in elderly patients remains a major therapeutic challenge. A multicenter, double-blind, randomized controlled trial with sacubitril/valsartan (LCZ696), a first-in-class angiotensin receptor neprilysin inhibitor, was conducted to determine its effects versus olmesartan (angiotensin receptor blocker) on central aortic pressures, in elderly patients (aged ≥60 years) with systolic hypertension and pulse pressure >60 mm Hg, indicative of arterial stiffness. Patients (n=454; mean age, 67.7 years; mean seated systolic blood pressure, 158.6 mm Hg; mean seated pulse pressure, 69.7 mm Hg) were randomized to receive once-daily sacubitril/valsartan 200 mg or olmesartan 20 mg, force titrated to double the initial doses after 4 weeks, before primary assessment at 12 weeks. The study extended double-blind treatment for 12 to 52 weeks, during which amlodipine (2.5-5 mg) and subsequently hydrochlorothiazide (6.25-25 mg) were added-on for patients not achieving blood pressure target (<140/90). At week 12, sacubitril/valsartan reduced central aortic systolic pressure (primary assessment) greater than olmesartan by -3.7 mm Hg (P=0.010), further corroborated by secondary assessments at week 12 (central aortic pulse pressure, -2.4 mm Hg, P<0.012; mean 24-hour ambulatory brachial systolic blood pressure and central aortic systolic pressure, -4.1 mm Hg and -3.6 mm Hg, respectively, both P<0.001). Differences in 24-hour ambulatory pressures were pronounced during sleep. After 52 weeks, blood pressure parameters were similar between treatments (P<0.002); however, more patients required add-on antihypertensive therapy with olmesartan (47%) versus sacubitril/valsartan (32%; P<0.002). Both treatments were equally well tolerated. The PARAMETER study (Prospective Comparison of Angiotensin Receptor Neprilysin Inhibitor With Angiotensin Receptor Blocker Measuring Arterial Stiffness in the Elderly), for the first time, demonstrated

  14. Systolic Signal Processor/High Frequency Direction Finding

    DTIC Science & Technology

    1990-10-01

    MUSIC ) algorithm and the finite impulse response (FIR) filter onto the testbed hardware was supported by joint sponsorship of the block and major bid...computational throughput. The systolic implementations of a four-channel finite impulse response (FIR) filter and multiple signal classification ( MUSIC ... MUSIC ) algorithm was mated to a bank of finite impulse response (FIR) filters and a four-channel data acquisition subsystem. A complete description

  15. Systolic time intervals in children with heart disease.

    PubMed

    Hedvall, G

    1983-03-01

    Of the systolic time intervals, the preejection period is known to correlate well with invasively measured isometric contraction time, and increase of the quotient preejection period/left ventricular ejection time (PEP/LVET) is considered to be of a good indicator of left ventricular failure. The different systolic time intervals have been recorded from the carotid pulse curve from 40 normal children, 20 aged five and 20 aged ten years. Their PEP/LVET was 0.31 +/- 0.04. Seventy-eight children with different heart diseases were then investigated. In patients with congenital total heart block or extrasystoles, there was a negative correlation between PEP/LVET and the R-R interval, in accordance with the Frank-Starling law. In patients with ventricular septal defects PEP/LVET differentiates between small and large shunts; the increased PEP/LVET of the latter normalizes after operation. The increased PEP/RVET of children with transposition of the great arteries is an expression of the inadequacy of the right ventricle as a systemic chamber. In aortic stenosis "normalization" of a previously decreased PEP/LVET may indicate early left ventricular failure. In primary myocardial disease registration of the systolic time intervals enables us to follow the left ventricular function more closely than is possible with invasive techniques.

  16. Coronary MR Angiography at 3T During Diastole and Systole

    PubMed Central

    Gharib, Ahmed M.; Herzka, Daniel A.; Ustun, Ali O.; Desai, Milind Y.; Locklin, Julia; Pettigrew, Roderic I.; Stuber, Matthias

    2016-01-01

    Purpose To investigate the impact of end-systolic imaging on quality of right coronary magnetic resonance angiography (MRA) in comparison to diastolic and to study the effect of RR interval variability on image quality. Materials and Methods The right coronary artery (RCA) of 10 normal volunteers was imaged at 3T using parallel imaging (sensitivity encoding [SENSE]). Navigator-gated three-dimensional (3D) gradient echo was used three times: 1) end-systolic short acquisition (SS): 35-msec window; 2) diastolic short (DS): middiastolic acquisition using 35-msec window; and 3) diastolic long (DL): 75-msec diastolic acquisition window. Vectorcardiogram (VCG) data was used to analyze RR variability. Vessel sharpness, length, and diameter were compared to each other and correlated with RR variability. Blinded qualitative image scores of the images were compared. Results Quantitative and qualitative parameters were not significantly different and showed no significant correlation with RR variability. Conclusion Imaging the RCA at 3T during the end-systolic rest period using SENSE is possible without significant detrimental effect on image quality. Breaking away from the standard of imaging only during diastole can potentially improve image quality in tachycardic patients or used for simultaneous imaging during both periods in a single scan. PMID:17896391

  17. Prevalence and Prognostic Value of Right Ventricular Systolic Dysfunction in Patients With Constrictive Pericarditis Who Underwent Pericardiectomy.

    PubMed

    Choudhry, Muhammad W; Homsi, Mohamed; Mastouri, Ronald; Feigenbaum, Harvey; Sawada, Stephen G

    2015-08-01

    Impaired right ventricular systolic function (RVSF) may complicate the treatment of constrictive pericarditis (CP) by pericardiectomy, which is a procedure that remains with significant morbidity and mortality. We evaluated RVSF in patients with CP who underwent pericardiectomy to determine the prognostic value of RVSF. RVSF was assessed by measuring Tricuspid Annular Plane Systolic Excursion (TAPSE) in 35 patients (mean age 52 ± 15.4 years) who underwent pericardiectomy. Thirty-one patients (88.6%) had reduced RVSF (TAPSE ≤1.8 cm). Eight patients (23%) had postoperative events (heart failure 3 and hospital mortality 5). Logistic regression showed that concomitant coronary artery bypass grafting (CABG) (p = 0.052), left ventricular ejection fraction (p = 0.059), left atrial diameter (p = 0.028), and TAPSE (p = 0.016) were borderline or significant univariate predictors of events. TAPSE (p = 0.018, odds ratio = 0.605 [0.40 to 0.92]) and CABG (p = 0.033, odds ratio = 20 [1.26 to 315]) were independent predictors of events on multivariate analysis. Stepwise analysis showed that TAPSE provided incremental prognostic value (p = 0.029, chi-square increase 11.6 to 16.3) to the combination of CABG, ejection fraction, and left atrial diameter. Receiver-operating characteristic curve analysis showed an area under the curve of 0.815 for TAPSE. TAPSE of 1.38 cm had a sensitivity of 88% and specificity of 67% for identifying patients with events. TAPSE was also inversely related to the length of hospital stay after pericardiectomy (p = 0.02, R = -0.424). Hence, our study showed that RVSF is frequently reduced in patients with CP who underwent pericardiectomy. In conclusion, TAPSE is an independent predictor of events and provides incremental prognostic value to other clinical and echocardiographic variables.

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

    SciTech Connect

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

    1996-06-01

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

  19. Cadmium block of isometric contractions of isolated bullfrog atrial cells.

    PubMed

    Shepherd, N; Kavaler, F; Spielman, W

    1991-02-01

    We studied the effect of cadmium, verapamil, and quinacrine on the force of contraction (Fp) of isolated, single, field-stimulated bullfrog atrial cells. All agents were applied or removed rapidly (t1/2 approximately 15 ms) to minimize intracellular concentration changes other than intracellular calcium concentration. Two components of twitch force were observed, one blocked by micromolar Cd2+ and the other by millimolar Cd2+. The two contributed about equally to the activation of the twitch. The "cadmium-sensitive" portion of force (that affected by [Cd] less than or equal to 100 microM) had a K1/2 approximately 1 microM, was identical in magnitude to, and not additive with, a "verapamil-sensitive" (10 microM) component of force, was most strongly affected by 50-ms pulses of Cd2+ when they were applied in the mechanical latent period, and was potentiated by catecholamines. The cadmium-insensitive portion of force was abolished by the removal of extracellular calcium and was greatly potentiated by quinacrine (3 or 10 microM), a blocker of Na-Ca exchange. The results are consistent with the idea that activating calcium enters the cell via both an inactivating cadmium-sensitive L-type channel and a noninactivating cadmium-insensitive mechanism that is not Na-Ca exchange and leaves the cell via Na-Ca exchange.

  20. A Unified Approach to the Analysis and Synthesis of Systolic Arrays.

    DTIC Science & Technology

    1985-04-01

    ANALYSIS AND SYNTHESIS OF SYSTOLIC ARRAYS... Analysis and Synthesis of Systolic Arrays N/A N/A N/A N/A 12. PERSONAL AUTHOR($) Hornick, Scot Wayne 13&. TYP OF REPORT K-J 1131L TIME COVERIO 14. OATS OF...frame- work to unify the analysis and synthesis of systolic networks. We describe a class of transformations on systolic networks that alter

  1. Association of genetic variants with atrial fibrillation.

    PubMed

    Yamase, Yuichiro; Kato, Kimihiko; Horibe, Hideki; Ueyama, Chikara; Fujimaki, Tetsuo; Oguri, Mitsutoshi; Arai, Masazumi; Watanabe, Sachiro; Murohara, Toyoaki; Yamada, Yoshiji

    2016-02-01

    Recent genome-wide association studies (GWASs) identified various genes and loci that confer susceptibility to coronary artery disease or myocardial infarction among Caucasian populations. As myocardial ischemia is an important risk factor for atrial fibrillation, we hypothesized that certain polymorphisms may contribute to the genetic susceptibility to atrial fibrillation through affecting the susceptibility to coronary artery disease. The aim of the present study was to examine the possible association of atrial fibrillation in Japanese individuals with 29 polymorphisms identified as susceptibility loci for coronary artery disease or myocardial infarction in the meta-analyses of GWASs in Caucasian populations. The study subjects comprised 5,470 Japanese individuals (305 subjects with atrial fibrillation and 5,165 controls). Genotypes for 29 polymorphisms were determined by a method that combines the polymerase chain reaction and sequence-specific oligonucleotide probes with suspension array technology. Comparisons of the allele frequencies by the χ(2) test revealed that rs599839 (G→A) of the proline/serine-rich coiled-coil 1 gene (PSRC1, P=0.0084) and rs11556924 (C→T, Arg363His) of the zinc finger, C3HC-type containing 1 gene (ZC3HC1, P=0.0076) were significantly (P<0.01) associated with atrial fibrillation. Multivariable logistic regression analysis with adjustment for age, gender, body mass index, estimated glomerular filtration rate, and the prevalence of smoking, hypertension, diabetes mellitus, and dyslipidemia revealed that rs599839 (P=0.0043; odds ratio, 1.56; dominant model) and rs11556924 (P=0.0043; odds ratio, 1.93; dominant model) were significantly associated with atrial fibrillation, with the minor G and T alleles, respectively, representing risk factors for this condition. PSRC1 and ZC3HC1 may thus be susceptibility loci for atrial fibrillation in Japanese individuals.

  2. Effect of phenylephrine infusion on atrial electrophysiological properties.

    PubMed Central

    Leitch, J. W.; Basta, M.; Fletcher, P. J.

    1997-01-01

    OBJECTIVE: To determine the effect of changes in autonomic tone induced by phenylephrine infusion on atrial refractoriness and conduction. DESIGN: Left and right atrial electrophysiological properties were measured before and after a constant phenylephrine infusion designed to increase sinus cycle length by 25%. SUBJECTS: 20 patients, aged 53 (SD 6) years, undergoing electrophysiological study for investigation of idiopathic paroxysmal atrial fibrillation (seven patients) or for routine follow up after successful catheter ablation of supraventricular tachycardia (13 patients). MAIN OUTCOME MEASURES: Changes in left and right atrial effective refractory periods, atrial activation times, and frequency of induction of atrial fibrillation. RESULTS: Phenylephrine (mean dose 69 (SD 18) mg/min) increased mean blood pressure by 22 (12) mm Hg (range 7 to 44) and lengthened sinus cycle length by 223 (94) ms (20 to 430). Left atrial effective refractory period lengthened following phenylephrine infusion from 250 (25) to 264 (21) ms (P < 0.001) but there was no significant change in right atrial effective refractory period: 200 (20) v 206 (29), P = 0.11. There was a significant relation between the effect of phenylephrine on sinus cycle length and on right atrial refractoriness (r = 0.6, P = 0.005) with shortening of right atrial refractoriness in patients with the greatest prolongation in sinus cycle length. During phenylephrine infusion, the right atrial stimulus to left atrial activation time at the basic pacing cycle length of 600 ms was unchanged, at 130 (18) v 131 (17) ms, but activation delay with a premature extrastimulus increased: 212 (28) v 227 (38) ms, P = 0.002. Atrial fibrillation was induced by two of 58 refractory period measurements at baseline and by 12 of 61 measurements during phenylephrine infusion (P < 0.01). Phenylephrine increased the difference between left and right atrial refractory periods by 22.8 (19.4) ms in the five patients with induced atrial

  3. Surgical repair of an atrial septal defect in a juvenile Sumatran orangutan (Pongo pygmaeus sumatraensis).

    PubMed

    Greenberg, M J; Janssen, D L; Jamieson, S W; Rothman, A; Frankville, D D; Cooper, S D; Kriett, J M; Adsit, P K; Shima, A L; Morris, P J; Sutherland-Smith, M

    1999-06-01

    A systolic heart murmur was auscultated in a 2-yr-old female Sumatran orangutan (Pongo pygmaeus sumatraensis) with a slower than expected growth rate. Cardiac ultrasound revealed an 11-mm atrial septal defect. Cardiac catheterization confirmed the diagnosis. Surgical repair was performed during cardiopulmonary bypass using a pericardial patch. The bypass pump was primed with human albumin and donor orangutan whole blood of a compatible type. Hematuria occurred shortly after the initiation of cardiopulmonary bypass. Successful repair was immediately confirmed with transesophageal ultrasonography. The animal was extubated shortly after returning to spontaneous ventilation but had to be reintubated 4 hr later due to tachypnea and decreased SpO2. Additional extubation attempts failed, necessitating continuous positive pressure ventilation, monitoring, and intensive care environment. Thoracic radiographs suggested adult respiratory distress syndrome. The animal required 14 days of intensive care before extubation of the trachea was successful. After 4 wk of isolation, the orangutan was successfully reintroduced to its family group.

  4. Echocardiographic evaluation of patent foramen ovale and atrial septal defect.

    PubMed

    Hari, Pawan; Pai, Ramdas G; Varadarajan, Padmini

    2015-01-01

    Patent foramen ovale (PFO) is a common variant present in up to 25% of the population. Atrial septal defect (ASD) is a direct communication between the 2 atrial chambers, of which the ostium secundum variety is the most common. This manuscript is an in depth review of the complex atrial septation, the diagnosis of PFO and ASD and its clinical and therapeutic implications.

  5. Predialysis systolic BP variability and outcomes in hemodialysis patients.

    PubMed

    Shafi, Tariq; Sozio, Stephen M; Bandeen-Roche, Karen J; Ephraim, Patti L; Luly, Jason R; St Peter, Wendy L; McDermott, Aidan; Scialla, Julia J; Crews, Deidra C; Tangri, Navdeep; Miskulin, Dana C; Michels, Wieneke M; Jaar, Bernard G; Herzog, Charles A; Zager, Philip G; Meyer, Klemens B; Wu, Albert W; Boulware, L Ebony

    2014-04-01

    BP variability (BPV) is an important predictor of outcomes in the general population, but its association with clinical outcomes in hemodialysis patients is not clear. We identified 11,291 patients starting dialysis in 2003-2008 and followed them through December 31, 2008 (median=22 months). Predialysis systolic BPV was assessed over monthly intervals. Outcomes included factors associated with BPV, mortality (all-cause and cardiovascular), and first cardiovascular event (cardiovascular death or hospitalization). Patients' mean age was 62 years, 55% of patients were men, and 58% of patients were white. Modifiable factors associated with higher BPV included obesity, higher calcium-phosphate product levels, and lower hemoglobin concentration; factors associated with lower BPV included greater fluid removal, achievement of prescribed dry weight during dialysis, higher hemoglobin concentration, and antihypertensive regimens without β-blockers or renin-angiotensin system blocking agents. In total, 3200 deaths occurred, including 1592 cardiovascular deaths. After adjustment for demographics, comorbidities, and clinical factors, higher predialysis BPV was associated with increased risk of all-cause mortality (hazard ratio [HR], 1.18; 95% confidence interval [95% CI] per 1 SD increase in BPV, 1.13 to 1.22), cardiovascular mortality (HR, 1.18; 95% CI, 1.12 to 1.24), and first cardiovascular event (HR, 1.11; 95% CI, 1.07 to 1.15). Results were similar when BPV was categorized in tertiles and patients were stratified by baseline systolic BP. In summary, predialysis systolic BPV is an important, potentially modifiable risk factor for death and cardiovascular outcomes in incident hemodialysis patients. Studies of BP management in dialysis patients should focus on both absolute BP and BPV.

  6. [Atrial defibrillators or implantable atrioverters. Initial results].

    PubMed

    Lévy, S; Taramasco, V; Corbelli, J L; Mistretta, R; Dolla, E; Ricard, P

    1998-07-01

    The atrial defibrillator is a new non-pharmacological treatment of atrial fibrillation (AF) for restoration of sinus rhythm. This device has two programmable modes: automatic or activated by the physician or patient. In the automatic mode, the device delivers a shock synchronous with the R wave to restore sinus rhythm when AF is detected. Two patients with paroxysmal AF resistant to pharmacological therapy were included in a study to assess the efficacy and safety of the atrial defibrillator in the mode activated by the physician. The device implanted in the pectoral region is connected to 3 electrodes, two for atrial defibrillation and sensing positioned in the coronary sinus and right atrium respectively and a sensing and pacing electrode in the right ventricle. The right ventricle is paced if a post-shock pause is detected. It is possible to interrogate the device with a programmer using its Holter function and so determine the number of episodes of AF sensed and treated. The number, intensity and energy of the shocks and the parameters of ventricular stimulation are programmable. In these two patients, the atrial defibrillator effectively reduced prolonged episodes of AF with a follow-up of 12 and 7 months. No pro-arrhythmic effects were observed. Further clinical evaluation is under way to assess this new mode of treatment, including the mode activated by the patient, safety and tolerance of the shocks. In our two patients, the treatment of prolonged episodes of AF was followed by reduction of many short or asymptomatic episodes.

  7. Restoration of Atrial Mechanical Function after Successful Radio-Frequency Catheter Ablation of Atrial Flutter

    PubMed Central

    Rhee, Kyoung-Suk; Kang, Duk-Hyun; Song, Jae-Kwan; Nam, Gi-Byoung; Choi, Kee-Joon; Kim, You-Ho

    2001-01-01

    Background: Atrial mechanical dysfunction and its recovery time course after successful radiofrequency ablation of chronic atrial flutter (AFL) has been largely unknown. We serially evaluated left atrial function by echocardiography after successful ablation of chronic atrial flutter. Methods: In 13 patients with chronic AFL, mitral E wave A wave, and the ratio of A/E velocity were measured at 1 day, 1 month, 3 months and 6–12 months after successful radiofrequency (RF) ablation. Doppler tissue imaging (DTI) technique was also used to avoid load-dependent variation in the flow velocity pattern. Results: Left atrial mechanical function, assessed by A wave velocity and the annular motion, was depressed at 1 day, but improved significantly at 1 month and maintained through 6–12 months after the ablation. Left atrial size did not change significantly. Conclusion: Left atrial mechanical function was depressed immediately after successful RF ablation of chronic AFL, but it improved significantly after 1 month and was maintained over one year. PMID:11590904

  8. Aorta-Right Atrial Tunnel

    PubMed Central

    Krishna, Cheemalapati Sai; Baruah, Dibya Kumar; Reddy, Gangireddy Venkateswara; Panigrahi, Nanda Kishore; Suman, Kalagara; Kumar, Palli Venkata Naresh

    2010-01-01

    Aorta–right atrial tunnel is a vascular channel that originates from one of the sinuses of Valsalva and terminates in either the superior vena cava or the right atrium. The tunnel is classified as anterior or posterior, depending upon its course in relation to the ascending aorta. An origin above the sinotubular ridge differentiates the tunnel from an aneurysm of the sinus of Valsalva, and the absence of myocardial branches differentiates it from a coronary–cameral fistula. Clinical presentation ranges from an asymptomatic precordial murmur to congestive heart failure. The embryologic background and pathogenesis of this lesion are attributable either to an aneurysmal dilation of the sinus nodal artery or to a congenital weakness of the aortic media. In either circumstance, progressive enlargement of the tunnel and ultimate rupture into the low-pressure right atrium could occur under the influence of the systemic pressure. The lesion is diagnosed by use of 2-dimensional echocardiography and cardiac catheterization. Computed tomographic angiography is an additional noninvasive diagnostic tool. The possibility of complications necessitates early therapy, even in asymptomatic patients or those with a hemodynamically insignificant shunt. Available treatments are catheter-based intervention, external ligation under controlled hypotension, or surgical closure with the patient under cardiopulmonary bypass. Herein, we discuss the cases of 2 patients who had this unusual anomaly. We highlight the outcome on follow-up imaging (patient 1) and the identification and safe reimplantation of the coronary artery (patient 2). PMID:20844628

  9. [Antithrombotic therapy in atrial arrhythmia].

    PubMed

    Cohen, Ariel

    2004-02-15

    The principal complication of the atrial arrythmias is the thrombo-embolic accident, notably the cerebro-vascular accident. The efficacity of the oral anticoagulants in reducing cerebro-vascular accidents has been demonstrated in numerous studies. This is significantly superior to that obtained with the anti-platelet drugs. However, the anti-vitamin K drugs (warfarin) carry a risk of serious haemorrhage of around 5% per year. This restricts the proposal of this treatment to patients with an elevated risk of vascular accidents: age, diabetes, previous cerebro-vascular accidents, and cardiac failure are the risk factors. Nevertheless, the risk of haemorrhage is responsible for an under prescription of the anticoagulants in the elderly. This explains the interest aroused by alternative therapeutics: the results of trials on ximelagatran, a direct anti-thrombin, are promising. In patients with an arrythmia, cardioversion carries a thrombo-embolic risk of around 1%. This risk is reduced by prior anticoagulant treatment. The procedure for this treatment is orientated by a trans-oesophageal echocardiogram. The incertitude of the duration of anticoagulant therapy without cardioversion calls for respect of the arrythmia. The treatment of this is limited to control of the cardiac rhythm and anticoagulant treatment.

  10. Aorta-right atrial tunnel.

    PubMed

    Sai Krishna, Cheemalapati; Baruah, Dibya Kumar; Reddy, Gangireddy Venkateswara; Panigrahi, Nanda Kishore; Suman, Kalagara; Kumar, Palli Venkata Naresh

    2010-01-01

    Aorta-right atrial tunnel is a vascular channel that originates from one of the sinuses of Valsalva and terminates in either the superior vena cava or the right atrium. The tunnel is classified as anterior or posterior, depending upon its course in relation to the ascending aorta. An origin above the sinotubular ridge differentiates the tunnel from an aneurysm of the sinus of Valsalva, and the absence of myocardial branches differentiates it from a coronary-cameral fistula. Clinical presentation ranges from an asymptomatic precordial murmur to congestive heart failure. The embryologic background and pathogenesis of this lesion are attributable either to an aneurysmal dilation of the sinus nodal artery or to a congenital weakness of the aortic media. In either circumstance, progressive enlargement of the tunnel and ultimate rupture into the low-pressure right atrium could occur under the influence of the systemic pressure.The lesion is diagnosed by use of 2-dimensional echocardiography and cardiac catheterization. Computed tomographic angiography is an additional noninvasive diagnostic tool. The possibility of complications necessitates early therapy, even in asymptomatic patients or those with a hemodynamically insignificant shunt. Available treatments are catheter-based intervention, external ligation under controlled hypotension, or surgical closure with the patient under cardiopulmonary bypass.Herein, we discuss the cases of 2 patients who had this unusual anomaly. We highlight the outcome on follow-up imaging (patient 1) and the identification and safe reimplantation of the coronary artery (patient 2).

  11. Cardiovascular Disease Update: Atrial Fibrillation.

    PubMed

    McDivitt, Johnathan D; Barstow, Craig

    2017-03-01

    Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. The prevalence increases with age, especially in the seventh and eighth decades of life. AF also is associated with multiple risk factors and conditions that are managed commonly in family medicine settings, such as hypertension and diabetes. Rhythm control and rate control are primarily equivalent for mortality rate, but patients treated for rhythm control have more hospitalizations; however, rhythm control may be a viable option for select patients. Beta blockers and nondihydropyridine calcium channel blockers can be used to achieve rate control. Pharmacotherapy or electrical cardioversion can be used to achieve rhythm control, and antiarrhythmic drugs are used to maintain sinus rhythm. Catheter ablation is an option for symptomatic patients whose AF is refractory to standard treatment. The CHA2DS2-VASc score should be used to predict the risk of stroke for patients with AF. Patients with nonvalvular AF and a history of stroke or transient ischemic attack or CHA2DS2-VASc scores of 2 or greater should be treated with warfarin or novel oral anticoagulants. Patients with valvular AF should be treated with warfarin.

  12. Diastolic Heart Failure Predicted by Left Atrial Expansion Index in Patients with Severe Diastolic Dysfunction

    PubMed Central

    Hsiao, Shih-Hung; Chiou, Kuan-Rau

    2016-01-01

    Background Left atrial (LA) echocardiographic parameters are increasingly used to predict clinically relevant cardiovascular events. The study aims to evaluate the LA expansion index (LAEI) for predicting diastolic heart failure (HF) in patients with severe left ventricular (LV) diastolic dysfunction. Methods This prospective study enrolled 162 patients (65% male) with preserved LV systolic function and severe diastolic dysfunction (132 grade 2 patients, 30 grade 3 patients). All patients had sinus rhythm at enrollment. The LAEI was calculated as (Volmax - Volmin) x 100% / Volmin, where Volmax was defined as maximal LA volume and Volmin was defined as minimal volume. The endpoint was hospitalization for HF withp reserved LV ejection fraction (HFpEF). Results The median follow-up duration was 2.9 years. Fifty-four patients had cardiovascular events, including 41 diastolic and 8 systolic HF hospitalizations. In these 54 patients, 13 in-hospital deaths and 5 sudden out-of-hospital deaths occurred. Multivariate analyses revealed that HFpEF was associated with LAEI.and atrial fibrillation during follow-up. For predicting HFpEF, the LAEI had a hazard ratio of 1.197per 10% decrease. In patients who had HFpEF events, the LAEI significantly (P< 0.0001) decreased from 69±18% to 39±11% during hospitalization. Although the LAEI improved during follow-up (53±13%), it did not return to baseline. Conclusions The LAEI predicts HFpEF in patients with severe diastolic dysfunction; it worsens during HFpEF events and partially recovers during followup. PMID:27622475

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    SciTech Connect

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

    1983-04-01

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

  15. Nitric Oxide Synthases and Atrial Fibrillation

    PubMed Central

    Bonilla, Ingrid M.; Sridhar, Arun; Györke, Sandor; Cardounel, Arturo J.; Carnes, Cynthia A.

    2012-01-01

    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 (NOS), which normally produce nitric oxide in the heart. Two NOS isoforms (1 and 3) are normally expressed in the heart. During pathologies such as heart failure, there is induction of NOS 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 NOS in the pathogenesis of atrial fibrillation. Therapeutic approaches to reduce atrial fibrillation by modulation of NOS activity may be beneficial, although further investigation of this strategy is needed. PMID:22536189

  16. Aneurysm of the Left Atrial Appendage

    PubMed Central

    Victor, Solomon; Nayak, Vijaya M.

    2001-01-01

    A 43-year-old woman underwent excision of an aneurysm of the left atrial appendage, which had been causing cerebrovascular embolic episodes. We attribute the aneurysm to congenital dysplasia of the musculi pectinati in the left atrial appendage and of the bands of atrial muscle from which they arise. In Appendix I, we draw attention to the morphologically similar arrangements of inner and outer bands that emanate from a common transverse interatrial band and yield morphologically similar medial, descending, and ascending palm-leaf arrangements of musculi pectinati. In addition, we observe that the strap-like arrangements of musculi in both atria connect the outer band with the para-annular segment of the inner band. In Appendix II, we briefly review the literature concerning musculi pectinati and related bands. PMID:11453121

  17. [Operative management of trigono-atrial lesions].

    PubMed

    Hussein, S

    1998-01-01

    Trigono-atrial-Lesions are microsurgically serios accessible, the results of transcortical aproaches are difficult and frequently unsatisfactory. The microsurgical anatomy of the trigono-atrial region will be studied on 100 brain hemispheres (the posterior cerebral arteries were injected selective on 70 hemispheres). According to the anatomical findings, an interhemispheric microsurgical approach has been developed. The operative results of 25 patients with different atrial lesions are presented. There was no operative mortality, the postoperative morbidity was 12%, in 24% (n = 6) the preoperative state was still unchanged, in 12 cases (48%) we note a normal neurological and neuropsychological postoperative status. In 4 patients (16%) the neurological symptoms are postoperatively improved. According to these first results, the described transatrial approach seems to be a real alternative for careful selected meanly leftsided lesions of the trigone.

  18. [Assessment right atrial function in patients with systemic lupus erythematosus by speckle tracking and three-dimensional echocardiography].

    PubMed

    Ge, X Y; Shao, L; Zheng, Z L

    2016-12-20

    Objective: To evaluate right atrial function in systemic lupus erythematosus (SLE) with normal pulmonary pressure by using two dimensional-speckle tracking imaging (2D-STI) and real-time three-dimensional echocardiography(RT-3DE). Methods: A totoal of 40 patients with SLE and 40 control subjects were collected between December 2011 and May 2014 from Ningbo Medical Treatment Center Lihuili Hospital. Right atrial global longitudinal strain (RAGLS) and all kinds of right atrium volume index (RAVI) were detected. Relationship between tricuspid annular plane systolic excursion(TAPSE), tricuspid annulus systolic peak velocity (S'), right ventricular myocardial performance index (RVMPI), ETV/e'TV and the right atrium parameters were analyzed. Results: SLE group's right atrium maximal volume index(RAVImax)(33.5±11.1) ml/m(2,) right atrium minimal volume index (RAVImin)(13.2±4.5) ml/m(2,) right atrium presystolic volume index (RAVIpre) (2.57±10.2) ml/m(2,) right atrium total emptying volume index(RAVIt)(20.2±8.1)ml/m(2,) right atrium active emptying volume index (RAVIa)(12.5±7.5) ml/m(2)) were increased .But right atrium passive emptying volume index(RAVIp)( 7.8±2.7) ml/m(2) and right atrial global longitudinal strain (RAGLS) (38.2%±7.7% ) were decreased (both P<0.05). RAGLS was positive correlated with S' and TAPSE, the r value were 0.565 and 0.445 respectively (both P<0.01). ETV/e'TV was positive correlated with RAVIpre, RAVIa, the r value were 0.469 and 0.481 respectively (both P<0.05). Conclusion: Detecting right atrial function by 2D-STI and RT-3DE could diagnose right atrial dysfunction in early stage of SLE patients with normal pulmonary pressure. The method is simple, has significant clinical value.

  19. Evaluation of left ventricular assist device performance and hydraulic force in a complete mock circulation loop.

    PubMed

    Timms, Daniel; Hayne, Mark; Tan, Andy; Pearcy, Mark

    2005-07-01

    Centrifugal pump performance characteristics are vital in determining the ability of a prototype left ventricular assist device (LVAD) to meet the physiological circulation requirements of the cardiovascular system. These characteristics influence the static hydraulic forces encountered by the pump impeller, which determine the required load stiffness of suspension type bearings to minimize impeller touchdown. Performance investigations were conducted on an LVAD design while characterizing the impeller static hydraulic forces of various impeller/volute configurations. The pumps were inserted into a complete systemic and pulmonary mock circulation rig configured to provide suitable nonpulsatile or simulated pulsatile left heart failure environments. The single volute and closed shroud impeller configuration exhibited lowest radial (0.01 N) and axial (3 N) force at nonpulsatile design flow conditions, respectively. Normal hemodynamic conditions of 5.1 L/min at 94 mm Hg were re-established upon inserting the device into the left heart failure environment, where the pump operated along the nonpulsatile characteristic curve for 2200 rpm. The operational limits on this curve were dictated by the required pressure differential across the pump during systolic and diastolic periods. The reduction of left atrial pressure (25 to 8 mm Hg) indicated the alleviation of pulmonary congestion. The ability for the LVAD to support circulation in a left heart failure environment was successfully demonstrated in the mock circulation loop. The impeller hydraulic force characteristics attained will aid the bearing designer to select the best volute and impeller configuration to minimize impeller touchdown in magnetic, hydrodynamic or mechanical type bearing applications.

  20. [Clinical characteristics of patients with persistent atrial fibrillation referred for cardioversion: Spanish Cardioversion Registry (REVERSE)].

    PubMed

    Alegret, Josep M; Viñolas, Xavier; Sagristá, Jaume; Hernández-Madrid, Antonio; Berruezo, Antonio; Moya, Angel; Martínez Sande, José L; Pastor, Agustín

    2008-06-01

    The objectives were to investigate the treatment and clinical characteristics of patients referred for cardioversion in Spain and to compare them with those reported in the AFFIRM (Atrial Fibrillation Follow-up Investigation of Rhythm Management) and RACE (RAte Control versus Electrical cardioversion) studies. The prospective study involved 1515 consecutive patients with persistent atrial fibrillation who were referred for cardioversion at 96 Spanish hospitals. Half of the patients were being treated with Vaughan-Williams group-I or -III antiarrhythmic drugs. The most frequently used approach to anticoagulation was to administer dicoumarins 34 weeks before and after cardioversion. Our patients were younger than those in the AFFIRM and RACE studies. Compared with AFFIRM patients, our patients had a lower prevalence of previous embolism, ischemic heart disease, hypertension, diabetes, and systolic dysfunction. Compared with RACE patients, our patients had a lower prevalence of ischemic heart disease and previous embolism, but a slightly higher prevalence of hypertension and diabetes. We conclude that patients referred for cardioversion in Spain clearly had a lower cardiovascular risk profile than those in the AFFIRM study, and appeared to have a lower risk profile than those in the RACE study.

  1. Changes in Left Ventricular Filling in Patients with Persistent Atrial Fibrillation

    PubMed Central

    Naji, Franjo; Pagliaruzzi, Mihael; Penko, Meta; Kanic, Vojko; Vokac, Damijan

    2013-01-01

    BACKGROUND: Former studies showed possible interrelationship between altered ventricular filling patterns and atrial fibrillation (AF). HYPOTHESIS: Long term persistent AF has a negative impact on left ventricular filling in patients with preserved ejection fraction of left ventricle. METHODS: Our study was designed as a prospective case control study. We included 40 patients with persistent AF and preserved ejection fraction after successful electrical cardioversion and 43 control patients. Persistent AF was defined as AF lasting more than 4 weeks. Cardiac ultrasound was performed in all patients 24 hours after the procedure. Appropriate mitral flow and tissue Doppler velocities as well as standard echocardiographic measurements were obtained. RESULTS: There were no significant differences between both groups' parameters regarding age, sex, commorbidities or drug therapy. Analysis of mitral flow velocities showed significant increase of E value in AF group (0.96±0.27 vs.0.70±0.14; p = 0.001). Tissue Doppler measurements didn't reveal any differences in early diastolic movement, however there was a statistically significant difference in E/Em values of both groups, respectively (12.0±4.0 vs. 9.0±2.1; p= 0.001). CONCLUSION: Our study shows that in patients with preserved systolic function and persistent AF shortly after cardioversion diastolic ventricular filling patterns are altered mainly due to increased left atrial pressure and not due to impaired diastolic relaxation of left ventricle. Further studies are needed in order to define the interplay between diminished atrial function and impaired ventricular filling. PMID:24324364

  2. Echocardiography of the intra-atrial baffle in dextro-transposition of the great vessels.

    PubMed

    Nanda, N D; Stewart, S; Gramiak, R; Manning, J A

    1975-06-01

    Twelve patients with dextro-transposition of the great vessels (age eight months to four years) were studied by echocardiography following Mustard's procedure. Nine of them had also been studied preoperatively. Postoperatively all patients demonstrated structural echoes in the atrial cavity behind the pulmonary root. In ten, the motion pattern generally resembled that of a stenotic atrioventricular valve iwth a sharp anterior movement followed by flattening in diastole and rapid posterior excursion in systole. The maximum amplitude of motion ranged from 4 to 9 mm (average 6.6 mm). In the remaining two cases, the anterior diastolic movement was attenuated. Similar moving, linear echoes with larger amplitudes of motion (10-14 mm) were observed behind the tricuspid valve in four patients while poorly moving, multiple or thick conglomerate echoes (2-11 mm wide) were detected in seven cases. Echocardiographic contrast studies performed by injecting indocyanine green via catheters placed on either side of the intra-atrial baffle identified it as the source of these echoes. Following operation, coarse diastolic undulations of the mitral valve (ten cases) and the tricuspid valve (nine cases) were noted. Also, fine flutter of both atrioventricular valves, not present before, appeared after operation in three patients. These findings may be related to the altered pathway of blood flow and turbulence resulting from the insertion of the baffle in the atria. Echocardiography appears useful in delineating the character and movement pattern of the intra-atrial baffle and this may have potential in evaluating its long-term functional status.

  3. Atrial Fibrillation in Decompensated Heart Failure: Associated Factors and In-Hospital Outcome

    PubMed Central

    Mendes, Fernanda de Souza Nogueira Sardinha; Atié, Jacob; Garcia, Marcelo Iorio; Gripp, Eliza de Almeida; de Sousa, Andréa Silvestre; Feijó, Luiz Augusto; Xavier, Sergio Salles

    2014-01-01

    Background Studies on atrial fibrillation (AF) in decompensated heart failure (DHF) are scarce in Brazil. Objectives To determine AF prevalence, its types and associated factors in patients hospitalized due to DHF; to assess their thromboembolic risk profile and anticoagulation rate; and to assess the impact of AF on in-hospital mortality and hospital length of stay. Methods Retrospective, observational, cross-sectional study of incident cases including 659 consecutive hospitalizations due to DHF, from 01/01/2006 to 12/31/2011. The thromboembolic risk was assessed by using CHADSVASc score. On univariate analysis, the chi-square, Student t and Mann Whitney tests were used. On multivariate analysis, logistic regression was used. Results The prevalence of AF was 40%, and the permanent type predominated (73.5%). On multivariate model, AF associated with advanced age (p < 0.0001), non-ischemic etiology (p = 0.02), right ventricular dysfunction (p = 0.03), lower systolic blood pressure (SBP) (p = 0.02), higher ejection fraction (EF) (p < 0.0001) and enlarged left atrium (LA) (p < 0.0001). The median CHADSVASc score was 4, and 90% of the cases had it ≥ 2. The anticoagulation rate was 52.8% on admission and 66.8% on discharge, being lower for higher scores. The group with AF had higher in-hospital mortality (11.0% versus 8.1%, p = 0.21) and longer hospital length of stay (20.5 ± 16 versus 16.3 ± 12, p = 0.001). Conclusions Atrial fibrillation is frequent in DHF, the most prevalent type being permanent AF. Atrial fibrillation is associated with more advanced age, non-ischemic etiology, right ventricular dysfunction, lower SBP, higher EF and enlarged LA. Despite the high thromboembolic risk profile, anticoagulation is underutilized. The presence of AF is associated with longer hospital length of stay and high mortality. PMID:25352505

  4. [The concise history of atrial fibrillation].

    PubMed

    Fazekas, Tamás

    2007-01-01

    The author reviews the history of atrial fibrillation, the most common sustained cardiac arrhythmia. The chaotic irregularity of arterial pulse was clearly acknowledged by most of physicians of the ancient China, Egypt and Greece. William Harvey (1578-1657), who first described the circulatory system appropriately, was probably the first to describe fibrillation of the auricles in animals in 1628. The French "clinical pathologist", Jean Baptist de Sénac (1693-1770) was the first who assumed a correlation between "rebellious palpitation" and stenosis of the mitral valve. Robert Adams (1791-1875) also reported in 1827 the association of irregular pulses and mitral stenosis. The discovery of digitalis leaf in 1785 by William Withering (1741-1799) brought relief to patients with atrial fibrillation and congestive heart failure by reducing the ventricular rate. From an analysis of simultaneously recorded arterial and venous pressure curves, the Scottish Sir James Mackenzie (1853-11925) demonstrated that a presystolic wave cannot be seen during "pulsus irregularis perpetuus", a term very first used by Heinrich Ewald Hering (1866-1948). Arthur Cushny (1866-1926) noted the similarity between pulse curves in clinical "delirium cordis" and those in dogs with atrial fibrillation. The first human ECG depicting atrial fibrillation was published by Willem Einthoven (1860-1927) in 1906. The proof of a direct connection between absolute arrhythmia and atrial fibrillation was established by two Viennese physicians, Carl Julius Rothberger and Heinrich Winterberg in 1909. Sir Thomas Lewis (1881-1945), the father of modem electrocardiography, studied electrophysiological characteristics of atrial fibrillation and has shown that its basic perpetuating mechanism is circus movement of electrical impulse (re-entry). After him, the major discoveries relating to the pathophysiology and clinical features of atrial fibrillation in the 20th century stemmed from Karel Frederick Wenckebach

  5. Antithrombotic Therapy for Atrial Fibrillation

    PubMed Central

    You, John J.; Singer, Daniel E.; Howard, Patricia A.; Lane, Deirdre A.; Eckman, Mark H.; Fang, Margaret C.; Hylek, Elaine M.; Schulman, Sam; Go, Alan S.; Hughes, Michael; Spencer, Frederick A.; Manning, Warren J.; Halperin, Jonathan L.

    2012-01-01

    Background: The risk of stroke varies considerably across different groups of patients with atrial fibrillation (AF). Antithrombotic prophylaxis for stroke is associated with an increased risk of bleeding. We provide recommendations for antithrombotic treatment based on net clinical benefit for patients with AF at varying levels of stroke risk and in a number of common clinical scenarios. Methods: We used the methods described in the Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines article of this supplement. Results: For patients with nonrheumatic AF, including those with paroxysmal AF, who are (1) at low risk of stroke (eg, CHADS2 [congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, prior stroke or transient ischemic attack] score of 0), we suggest no therapy rather than antithrombotic therapy, and for patients choosing antithrombotic therapy, we suggest aspirin rather than oral anticoagulation or combination therapy with aspirin and clopidogrel; (2) at intermediate risk of stroke (eg, CHADS2 score of 1), we recommend oral anticoagulation rather than no therapy, and we suggest oral anticoagulation rather than aspirin or combination therapy with aspirin and clopidogrel; and (3) at high risk of stroke (eg, CHADS2 score of ≥ 2), we recommend oral anticoagulation rather than no therapy, aspirin, or combination therapy with aspirin and clopidogrel. Where we recommend or suggest in favor of oral anticoagulation, we suggest dabigatran 150 mg bid rather than adjusted-dose vitamin K antagonist therapy. Conclusions: Oral anticoagulation is the optimal choice of antithrombotic therapy for patients with AF at high risk of stroke (CHADS2 score of ≥ 2). At lower levels of stroke risk, antithrombotic treatment decisions will require a more individualized

  6. Lunar influence on atrial fibrillation?

    PubMed

    Mikulecky, M; Valachova, A

    1996-08-01

    The most popular periodicities in biology and medicine-the circadians and circannuals-stem undoubtedly from the Earth's rotation and its revolution around the sun. The problem is how to explain the existence of circaseptan, i.e. 5-9-day, and other infradian rhythms. They may correspond to the lunar cycles and their 2nd to 6th harmonics. To test such hypothesis, the calendar dates of 127 attacks of atrial fibrillation in one male subject (M.M.) between 1980 and 1994 were transformed into the days numbered 0-29 for the synodic, and 0-26 for tropic lunar cycle. The daily frequencies obtained in this way were smoothed by moving averages of three successive days each. Considerable fluctuations of frequencies of attacks during both cycles were visible by inspection of the corresponding graphs, called lunar plexograms. Thus, a conspicuous nadir is found under the full moon in the synodic cycle, and a marked peak shortly after the extreme southern position of the moon in the tropic cycle. Halberg's cosinor analysis testing the presence of the 1st to 6th harmonic of either lunar cycle rejected the null hypothesis at the alpha = 0.05 level for all harmonics. Accordingly, the occurrence of attacks was cycling with the period lengths of synodic and tropic lunar cycles, and with those of their 1/2-1/6 period lengths, i.e. with a cluster of approximately circa(di)-septan rhythms. This conclusion is supported by similar findings obtained earlier for various medical and biological events.

  7. Dabigatran etexilate in atrial fibrillation.

    PubMed

    Vora, Amit

    2013-12-01

    Atrial fibrillation (AF) affects millions worldwide. Stroke is the most devastating complication of AF and is associated with a huge disease burden. As a preventive measure, anticoagulant therapy is recommended for most AF patients based on presence of stroke risk factors. For the past six decades warfarin remained the gold standard for stroke prevention in AF (SPAF). However, it is associated with numerous limitations such as a high risk of drug-drug, drug-food interactions and need for frequent INR (2-3) monitoring. Novel oral anticoagulant (NOAC) dabigatran etexilate is a selective, specific, reversible direct thrombin inhibitor that has been approved in India for SPAF and primary venous thromboembolism prevention. The efficacy and safety of dabigatran in AF has been established the "Randomized Evaluation of Long-Term Anticoagulant Therapy (RE-LY)", a randomized clinical trial. RE-LY (n = 18,113) demonstrated that the efficacy of dabigatran 110 mg BID was as good as well controlled warfarin and dabigatran 150 mg BID reduced the risk of ischaemic stroke by 25% (P = 0.03). Till date, 150mg dabigatran is the only NOAC offering a superior reduction in most commonly seen ischemic strokes due to AF compared to warfarin. Additionally, both doses of dabigatran significantly reduced the risk of total bleeds, intracranial, and life threatening bleeds versus warfarin (p < 0.05). Dabigatran has advantages over warfarin including predictable pharmacokinetic/pharmacodynamic profile, minimal drug-drug and no drug-food interactions while no monitoring is needed.The 150 mg dose of dabigatran should be considered in younger patients with a low risk of bleeding and good renal function to achieve a superior ischemic stroke reduction, whereas, the 110 mg dose should be considered in elderly patients, those with mild to moderate renal function or those with high risk of bleeding.

  8. Effect of acute pericardial tamponade on the relative contributions of systolic and diastolic pulmonary venous return: a transesophageal pulsed Doppler study.

    PubMed

    Louie, E K; Hariman, R J; Wang, Y; Hwang, M H; Loeb, H S; Scanlon, P J

    1995-01-01

    The effect of acute pericardial tamponade on pulmonary venous return was assessed by transesophageal pulsed Doppler echocardiography. In 14 open-chest anesthetized dogs peak pulmonary venous flow velocities in systole (VJ) and in diastole (VK) were measured during apnea and atrial pacing while acute tamponade was induced by intrapericardial instillation of 0.9% sodium chloride solution. Before intravascular volume expansion, induction of acute tamponade resulted in a significant decline in VK (43 +/- 17 to 19 +/- 8 cm/sec; p < 0.05) but no change in VJ or the ratio VJ/VK. After intravascular volume expansion, induction of acute tamponade resulted in significant reductions in VJ (43 +/- 9 to 29 +/- 10 cm/sec; p < 0.001) and VK (37 +/- 19 to 15 +/- 11 cm/sec; p < 0.001). The effect was disproportionately greater on VK, however, resulting in a significant increase in VJ/VK (1.51 +/- 0.84 to 2.58 +/- 1.41; p < 0.001). The disproportionate effect of acute tamponade on VK suggests that increased pericardial pressure directly constrains diastolic filling of the left atrium as a conduit to the left ventricle and that it does not decrease the systolic and diastolic phases of pulmonary venous return uniformly. Intravascular volume expansion increases cardiac output before acute tamponade, but during acute tamponade it amplifies the disproportionate impact of increased pericardial pressure on left ventricular diastolic filling as the left ventricle is constrained within the fluid-filled pericardial sac.

  9. Two-dimensional echocardiographic determination of right atrial emptying volume: a noninvasive index in quantifying the degree of tricuspid regurgitation.

    PubMed

    DePace, N L; Ren, J F; Kotler, M N; Mintz, G S; Kimbiris, D; Kalman, P

    1983-09-01

    Contrast echocardiography and inferior vena cava ultrasonography are useful techniques in diagnosing tricuspid regurgitation (TR) but are not helpful in estimating the severity. Using a computerized light-pen method for tracing the right atrial (RA) border during systole and diastole in the apical 4-chamber view, single-plane volume determinations were calculated in 10 normal subjects (Group I), 18 patients with atrial fibrillation (AF) and no TR (Group II), 14 patients with mitral stenosis and mild TR (Group IIIa), and 8 patients with mitral stenosis and severe TR (Group IIIb). TR was quantitated as absent, mild or severe by contrast right ventriculography. The RA end-systolic volume was 36.4 +/- 13.1 ml in Group I patients, 59.1 +/- 16.8 ml in Group II patients, 76.9 +/- 55.4 ml in Group IIIa patients, and 154.6 +/- 57.3 ml in Group IIIb patients (all Groups versus Group I, p less than 0.001). The mean RA emptying volume, which equals RA end-systolic volume--RA end-diastolic volume, was 15.3 +/- 5.0 for Group I, 17.7 +/- 3.0 for Group II, 30.4 +/- 8.0 for Group IIIa, and 71.6 +/- 25.4 for Group IIIb. All 8 patients with severe TR but none of the 14 patients with mild TR had an RA emptying volume greater than 40 ml (p less than 0.001). In addition, all 28 patients in Groups I and II but only 4 of 14 patients in Group III had an RA emptying volume less than 26 ml (p less than 0.01). The mean RA pressure measured at cardiac catheterization correlated with RA emptying volume (r = 0.71, p less than 0.001). Thus, RA emptying volume is useful for separating severe TR from mild TR in patients with mitral stenosis.

  10. A rare large right atrial myxoma with rapid growth rate.

    PubMed

    Kelly, Shawn C; Steffen, Kelly; Stys, Adam T

    2014-10-01

    Atrial myxomas are the most common benign intracavitary cardiac neoplasms. They most frequently occur in the left atrium. Right atrial tumors are rare, comprising 20 percent of myxomas achieving an incidence of 0.02 percent. Due to their rarity, right atrial tumor development and associated clinical symptoms has not been well described. The classical clinical triad for the presentation of left atrial myxomas--heart failure, embolic events, and constitutional symptoms--may not be applicable to right sided tumors. Also, natural development of myxoma is not well described, as surgical resection is the common practice. Previously ascribed growth rates of myxomas refer mostly to left atrial ones, as right atrial tumors are rare. We present a case of right atrial myxoma with growth rates exceeding those previously described.

  11. An improved method for echographic detection of left atrial enlargement

    NASA Technical Reports Server (NTRS)

    Brown, O. R.; Harrison, D. C.; Popp, R. L.

    1974-01-01

    Echographic dimensions of the aortic root and left atrium were compared in 170 patients in order to assess dilation of the left atrium with reference to the relatively nondistensible fibrous aortic root. In 50 patients without cause for left atrial or aortic enlargement, the ratio of left atrial/aortic root dimensions was 0.87 to 1.11. In 80 patients with known cause for left atrial enlargement, the left atrial/aortic root ratio was greater than or equal to 1.17. In 40 patients with isolated valve disease, dilation of both the aortic root and the left atrium resulted in a left atrial/aortic root dimension ratio less than 1.17 in some patients. Despite this consideration, the comparison of left atrial and aortic root dimension appears to be as specific as, and more sensitive than, previously proposed methods for the evaluation of left atrial enlargement.

  12. Digitalis does not improve left atrial mechanical dysfunction after successful electrical cardioversion of chronic atrial fibrillation.

    PubMed

    Yujing, Wang; Congxin, Huang; Shaning, Yang; Lijun, Jin; Xiaojun, Hu; Gang, Wu; Qiang, Xie

    2010-05-01

    This study was designed to investigate whether administration of digitalis could improve mechanical function of left atrial appendage (LAA) and left atrium prospectively in patients with atrial stunning. Fifty-four consecutive patients in whom atrial stunning was observed immediately after cardioversion of chronic atrial fibrillation (AF) were randomized into digitalis or control group for 1 week following cardioversion. Transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) were performed prior to, immediately following, 1 day after and 1 week after cardioversion to measure transmitral flow velocity and LAA flow velocity. Electrical cardioversion of AF elicited significantly slower left atrial appendage peak emptying velocity (LAA-PEV) and peak filling velocity (LAA-PFV) immediately following cardioversion in both groups. 1 day post cardioversion, there were no significant differences in transmitral E wave, A wave, E/A ratio, LAA-PEV, LAA-PFV or left atrial appendage ejection fraction (LAA-EF) between digitalis and control groups. 1 week post cardioversion, no significant differences were found in transmitral E wave, A wave, E/A ratio, LAA-PEV, LAA-PFV or LAA-EF between the two groups. The occurrence rates of spontaneous echo contrast were not significantly different between digitalis and control groups one day and one week post cardioversion. In conclusion, digitalis did not improve left atrial and appendage mechanical dysfunction following cardioversion of chronic AF. Digitalis did not prevent the development of spontaneous echo contrast in left atrial chamber and appendage. This may be due to the fact that digitalis aggravates intracellular calcium overload induced by chronic AF and has a negative effect on ventricular rate.

  13. Computational models of atrial cellular electrophysiology and calcium handling, and their role in atrial fibrillation.

    PubMed

    Heijman, Jordi; Erfanian Abdoust, Pegah; Voigt, Niels; Nattel, Stanley; Dobrev, Dobromir

    2016-02-01

    The complexity of the heart makes an intuitive understanding of the relative contribution of ion channels, transporters and signalling pathways to cardiac electrophysiology challenging. Computational modelling of cardiac cellular electrophysiology has proven useful to integrate experimental findings, extrapolate results obtained in expression systems or animal models to other systems, test quantitatively ideas based on experimental data and provide novel hypotheses that are experimentally testable. While the bulk of computational modelling has traditionally been directed towards ventricular bioelectricity, increasing recognition of the clinical importance of atrial arrhythmias, particularly atrial fibrillation, has led to widespread efforts to apply computational approaches to understanding atrial electrical function. The increasing availability of detailed, atrial-specific experimental data has stimulated the development of novel computational models of atrial-cellular electrophysiology and Ca(2+) handling. To date, more than 300 studies have employed mathematical simulations to enhance our understanding of atrial electrophysiology, arrhythmogenesis and therapeutic responses. Future modelling studies are likely to move beyond current whole-cell models by incorporating new data on subcellular architecture, macromolecular protein complexes, and localized ion-channel regulation by signalling pathways. At the same time, more integrative multicellular models that take into account regional electrophysiological and Ca(2+) handling properties, mechano-electrical feedback and/or autonomic regulation will be needed to investigate the mechanisms governing atrial arrhythmias. A combined experimental and computational approach is expected to provide the more comprehensive understanding of atrial arrhythmogenesis that is required to develop improved diagnostic and therapeutic options. Here, we review this rapidly expanding area, with a particular focus on Ca(2+) handling, and

  14. Reversible Changes of Left Atrial Function during Pregnancy Assessed by Two-Dimensional Speckle Tracking Echocardiography

    PubMed Central

    Song, Guang; Liu, Jing; Ren, Weidong; Qiao, Wei; Zhang, Jing; Zhan, Ying; Bi, Wenjing

    2015-01-01

    Background Left ventricular diastolic function is impaired during pregnancy. However, changes in left atrial (LA) function remain unclear. We aimed to evaluate changes in LA function during pregnancy using two-dimensional speckle tracking echocardiography (2DSTE). Methods and Results 50 pregnant and 50 healthy nulliparous (control group) women were enrolled in this study. All pregnant women were followed up postpartum in sixth-month. The LA maximum volume, LA minimal volume and LA preatrial contraction volume were obtained using biplane modified Simpson’s method. LA filling volume, LA expansion index, LA ejection fraction, passive volume, passive emptying index, active volume, and active emptying index were calculated. LA longitudinal systolic strain (SS), systolic strain rate (s-SR), early diastolic strain rate (e-SR), and late diastolic strain rate (a-SR) were obtained by 2DSTE. Compared to the control group, the reservoir function was increased in pregnant patients (P<0.05); conduit function was decreased in pregnant patients (P<0.05); booster pump function was increased in pregnant patients (P<0.05). There was no statistically significant difference between the control group and postpartum group. Conclusions LA reservoir and booster pump function were increased, while conduit function was decreased during pregnancy using 2DSTE. The changes were reversible. 2DSTE can easily assess LA function during pregnancy with good repeatability. PMID:25933100

  15. Automated measurement of office, home and ambulatory blood pressure in atrial fibrillation.

    PubMed

    Kollias, Anastasios; Stergiou, George S

    2014-01-01

    1. Hypertension and atrial fibrillation (AF) often coexist and are strong risk factors for stroke. Current guidelines for blood pressure (BP) measurement in AF recommend repeated measurements using the auscultatory method, whereas the accuracy of the automated devices is regarded as questionable. This review presents the current evidence on the feasibility and accuracy of automated BP measurement in the presence of AF and the potential for automated detection of undiagnosed AF during such measurements. 2. Studies evaluating the use of automated BP monitors in AF are limited and have significant heterogeneity in methodology and protocols. Overall, the oscillometric method is feasible for static (office or home) and ambulatory use and appears to be more accurate for systolic than diastolic BP measurement. 3. Given that systolic hypertension is particularly common and important in the elderly, the automated BP measurement method may be acceptable for self-home and ambulatory monitoring, but not for professional office or clinic measurement. 4. An embedded algorithm for the detection of asymptomatic AF during routine automated BP measurement with high diagnostic accuracy has been developed and appears to be a useful screening tool for elderly hypertensives.

  16. "Sawfish" systolic narrowing of the left anterior descending coronary artery: an angiographic sign of hypertrophic cardiomyopathy.

    PubMed

    Brugada, P; Bär, F W; de Zwaan, C; Roy, D; Green, M; Wellens, H J

    1982-10-01

    The morphologic characteristics at coronary arteriography of systolic narrowing of the left anterior descending coronary artery (LAD) were evaluated in 14 patients. Six patients had systolic narrowing of the LAD not associated with other cardiac abnormalities (group A) and eight patients had systolic narrowing of the LAD associated with hypertrophic cardiomyopathy (group B). Patients in group A showed a smooth and progressive constriction of the vessel up to the point of maximal stenosis, giving it a "rat-tail" appearance. There was no systolic narrowing of septal branches or of other epicardial vessels in this group. In patients of group B, systolic narrowing of the LAD had a "saw-fish" appearance. Seven patients had systolic narrowing of the septal branches, and five had systolic narrowing of other epicardial vessels. These data indicate that systolic narrowing of the LAD in patients with hypertrophic cardiomyopathy differs angiographically from systolic narrowing due to an intramural course of a part of the vessel (as in group A patients). We postulate that in patients with hypertropic cardiomyopathy, fiber hypertrophy and disarray in the vicinity of the coronary vessels is responsible for the morphology and the widespread distribution of systolic narrowing.

  17. Characterization of the functional and anatomical differences in the atrial and ventricular myocardium from three species of elasmobranch fishes: smooth dogfish (Mustelus canis), sandbar shark (Carcharhinus plumbeus), and clearnose skate (Raja eglanteria).

    PubMed

    Larsen, Julie; Bushnell, Peter; Steffensen, John; Pedersen, Morten; Qvortrup, Klaus; Brill, Richard

    2017-02-01

    We assessed the functional properties in atrial and ventricular myocardium (using isolated cardiac strips) of smooth dogfish (Mustelus canis), clearnose skate (Raja eglanteria), and sandbar shark (Carcharhinus plumbeus) by blocking Ca(2+) release from the sarcoplasmic reticulum (SR) with ryanodine and thapsigargin and measuring the resultant changes in contraction-relaxation parameters and the force-frequency relationship at 20 °C and 30 °C. We also examined ultrastructural differences with electron microscopy. In tissues from smooth dogfish, net force (per cross-sectional area) and measures of the speeds of contraction and relaxation were all higher in atrial than ventricular myocardium at both temperatures. Atrial-ventricular differences were evident in the other two species primarily in measures of the rates of contraction and relaxation. Ryanodine-thapsigargin treatment reduced net force and its maximum positive first derivative (i.e., contractility), and increased time to 50 % relaxation in atrial tissue from smooth dogfish at 30 °C. It also increased times to peak force and half relaxation in clearnose skate atrial and ventricular tissue at both temperatures, but only in atrial tissue from sandbar shark at 30 °C; indicating that SR involvement in excitation-contraction (EC) coupling is species- and temperature-specific in elasmobranch fishes, as it is in teleost fishes. Atrial and ventricular myocardium from all three species displayed a negative force-frequency relationship, but there was no evidence that SR involvement in EC coupling was influenced by heart rate. SR was evident in electron micrographs, generally located in proximity to mitochondria and intercalated discs, and to a lesser extent between the myofibrils; with mitochondria being more numerous in ventricular than atrial myocardium in all three species.

  18. Effect of years of endurance exercise on risk of atrial fibrillation and atrial flutter.

    PubMed

    Myrstad, Marius; Nystad, Wenche; Graff-Iversen, Sidsel; Thelle, Dag S; Stigum, Hein; Aarønæs, Marit; Ranhoff, Anette H

    2014-10-15

    Emerging evidence suggests that endurance exercise increases the risk for atrial fibrillation (AF) in men, but few studies have investigated the dose-response relation between exercise and risk for atrial arrhythmias. Both exposure to exercise and reference points vary among studies, and previous studies have not differentiated between AF and atrial flutter. The aim of this study was to assess the risk for atrial arrhythmias by cumulative years of regular endurance exercise in men. To cover the range from physical inactivity to long-term endurance exercise, the study sample in this retrospective cohort study was based on 2 distinct cohorts: male participants in a long-distance cross-country ski race and men from the general population, in total 3,545 men aged ≥ 53 years. Arrhythmia diagnoses were validated by electrocardiograms during review of medical records. Regular endurance exercise was self-reported by questionnaire. A broad range of confounding factors was available for adjustment. The adjusted odds ratios per 10 years of regular endurance exercise were 1.16 (95% confidence interval 1.06 to 1.29) for AF and 1.42 (95% confidence interval 1.20 to 1.69) for atrial flutter. In stratified analyses, the associations were significant in cross-country skiers and in men from the general population. In conclusion, cumulative years of regular endurance exercise were associated with a gradually increased risk for AF and atrial flutter.

  19. Relationship between body mass index and left atrial appendage thrombus in nonvalvular atrial fibrillation.

    PubMed

    Cohoon, Kevin P; McBane, Robert D; Ammash, Naser; Slusser, Joshua P; Grill, Diane E; Wysokinski, Waldemar E

    2016-05-01

    Atrial fibrillation and obesity are two major growing epidemics in the United States and globally. Obese people are at the increased risk of developing atrial fibrillation. The contribution of obesity as an independent risk factor for stroke in the setting of atrial fibrillation remains unclear. We tested the hypothesis that non-valvular atrial fibrillation (NVAF) patients with increased body mass index (BMI) would be at increased risk for the development of left atrial appendage thrombus (LAAT). Consecutive, anticoagulation naïve patients with NVAF referred for a transesophageal echocardiogram (TEE) between January 1, 2007 and October 21, 2009 were approached for study participation. All clinical, laboratory, and TEE measurement data were collected prospectively. Within a group of 400 anticoagulation naïve NVAF patients (mean age 63 ± 15 years, 28 % women; 17 % with LAAT) the prevalence of LAAT was similar across all BMI categories (normal 13 %, overweight 19 %, obese 16 %, morbidly obese 16 %; p = 0.71). Despite a higher CHADS2 score and a higher prevalence of both hypertension and diabetes mellitus, elevated BMI was not an independent predictor of LAAT when analyzed as either a continuous variable, across BMI WHO categories, a dichotomous variable stratified at values above versus below 27 kg/m(2), or BMI stratified on atrial fibrillation duration. Despite a higher prevalence of major risk factors for thromboembolism, the prevalence of LAAT was not increased in overweight, obese, and morbidly obese patients.

  20. The effect of asanguinous cardioplegic arrest on atrial preservation using atrial ATP as a marker.

    PubMed

    Hines, G L; Scheaffer, P; Williams, L; Mantell, P; Cheifitz, P

    1990-01-01

    Changes in atrial adenosine triphosphate (ATP) and the presence of postoperative arrhythmias were studied in 14 patients during routine coronary artery bypass grafting to 1) attempt to evaluate atrial preservation, and 2) determine if a relationship exists between changes in ATP and the development of postoperative arrhythmias. Atrial biopsies were obtained at the time of cannulation (preischemic sample) and after the removal of the aortic crossclamp (postischemic sample). Methods of myocardial protection included systemic hypothermia (28 degrees C), periodic reinfusion of crystalloid cardioplegia into the aortic root and completed vein grafts, and iced slush in the pericardial well. Atrial temperature was monitored. Preischemic ATP was 0.412 +/- 0.32 mu mol/gm, and the postischemic value was 0.220 +/- 0.13 mu mol/gm (p less than .02). Atrial temperature routinely decreased to 13-18 degrees C after cardioplegic infusion but rose to 24 degrees C between infusions. There was no correlation between postoperative supraventricular arrhythmias (4 patients) and changes in ATP. In conclusion, routine coronary artery bypass grafting with standard methods of cardiac preservation does not appear to satisfactorily preserve atrial tissue. The clinical correlation and significance of this remains to be elucidated.

  1. Left Atrial Function Predicts Heart Failure Hospitalization in Subjects with Preserved Ejection Fraction and Coronary Heart Disease: Longitudinal Data from the Heart and Soul Study

    PubMed Central

    Welles, Christine C.; Ku, Ivy A.; Kwan, Damon M.; Whooley, Mary A.; Schiller, Nelson B.; Turakhia, Mintu P.

    2012-01-01

    Objectives We sought to determine whether left atrial (LA) dysfunction predicts heart failure (HF) hospitalization in subjects with preserved baseline ejection fraction (EF). Background Among patients with preserved EF, factors leading to HF are not fully understood. Cross-sectional studies have demonstrated LA dysfunction at the time of HF, but longitudinal data on antecedent atrial function are lacking. Methods We performed resting transthoracic echocardiography in 855 subjects with coronary heart disease and EF≥50%. Left atrial functional index (LAFI) was calculated as [(LA emptying fraction × left ventricular outflow tract-velocity time integral)/(indexed LA end systolic volume)], where LA emptying fraction was defined as (LA end systolic volume - LA end diastolic volume)/LA end systolic volume. We used Cox models to evaluate the association between LAFI and HF hospitalization. Results Over a median follow-up of 7.9 years, 106 participants (12.4%) were hospitalized for HF. Rates of HF hospitalization were inversely proportional to quartile of LAFI: Q1: 47 per 1000 person-years; Q2: 18.3; Q3: 9.6; and Q4: 5.3 (p<0.001). Each standard deviation decrease in LAFI was associated with a 2.6-fold increased hazard of adverse cardiovascular outcomes (unadjusted HR: 2.6, 95% CI 2.1–3.3, p<0.001), and the association persisted even after adjustment for clinical risk factors, NT-proBNP, and a wide range of echocardiographic parameters (adjusted HR: 1.5, 95% CI 1.0–2.1, p=0.05). Conclusions LA dysfunction independently predicts HF hospitalization in subjects with coronary heart disease and preserved baseline EF. LAFI may be useful for HF risk stratification, and LA dysfunction may be a potential therapeutic target. PMID:22322084

  2. Abnormal splicing in the N‐terminal variable region of cardiac troponin T impairs systolic function of the heart with preserved Frank‐Starling compensation

    PubMed Central

    Feng, Han‐Zhong; Chen, Guozhen; Nan, Changlong; Huang, Xupei; Jin, Jian‐Ping

    2014-01-01

    Abstract Abnormal splice‐out of the exon 7‐encoded segment in the N‐terminal variable region of cardiac troponin T (cTnT‐ΔE7) was found in turkeys and, together with the inclusion of embryonic exon (eTnT), in adult dogs with a correlation with dilated cardiomyopathy. Overexpression of these cTnT variants in transgenic mouse hearts significantly decreased cardiac function. To further investigate the functional effect of cTnT‐ΔE7 or ΔE7+eTnT in vivo under systemic regulation, echocardiography was carried out in single and double‐transgenic mice. No atrial enlargement, ventricular hypertrophy or dilation was detected in the hearts of 2‐month‐old cTnT‐ΔE7 and ΔE7+eTnT mice in comparison to wild‐type controls, indicating a compensated state. However, left ventricular fractional shortening and ejection fraction were decreased in ΔE7 and ΔE7+eTnT mice, and the response to isoproterenol was lower in ΔE7+eTnT mice. Left ventricular outflow tract velocity and gradient were decreased in the transgenic mouse hearts, indicating decreased systolic function. Ex vivo working heart function showed that high afterload or low preload resulted in more severe decreases in the systolic function and energetic efficiency of cTnT‐ΔE7 and ΔE7+eTnT hearts. On the other hand, increases in preload demonstrated preserved Frank‐Starling responses and minimized the loss of cardiac function and efficiency. The data demonstrate that the N‐terminal variable region of cardiac TnT regulates systolic function of the heart. PMID:25194024

  3. Abnormal splicing in the N-terminal variable region of cardiac troponin T impairs systolic function of the heart with preserved Frank-Starling compensation.

    PubMed

    Feng, Han-Zhong; Chen, Guozhen; Nan, Changlong; Huang, Xupei; Jin, Jian-Ping

    2014-09-01

    Abnormal splice-out of the exon 7-encoded segment in the N-terminal variable region of cardiac troponin T (cTnT-ΔE7) was found in turkeys and, together with the inclusion of embryonic exon (eTnT), in adult dogs with a correlation with dilated cardiomyopathy. Overexpression of these cTnT variants in transgenic mouse hearts significantly decreased cardiac function. To further investigate the functional effect of cTnT-ΔE7 or ΔE7+eTnT in vivo under systemic regulation, echocardiography was carried out in single and double-transgenic mice. No atrial enlargement, ventricular hypertrophy or dilation was detected in the hearts of 2-month-old cTnT-ΔE7 and ΔE7+eTnT mice in comparison to wild-type controls, indicating a compensated state. However, left ventricular fractional shortening and ejection fraction were decreased in ΔE7 and ΔE7+eTnT mice, and the response to isoproterenol was lower in ΔE7+eTnT mice. Left ventricular outflow tract velocity and gradient were decreased in the transgenic mouse hearts, indicating decreased systolic function. Ex vivo working heart function showed that high afterload or low preload resulted in more severe decreases in the systolic function and energetic efficiency of cTnT-ΔE7 and ΔE7+eTnT hearts. On the other hand, increases in preload demonstrated preserved Frank-Starling responses and minimized the loss of cardiac function and efficiency. The data demonstrate that the N-terminal variable region of cardiac TnT regulates systolic function of the heart.

  4. Real-time neuronal networks reconstruction using hierarchical systolic arrays.

    PubMed

    Yu, Bo; Mak, Terrence; Sun, Yihe; Poon, Chi-Sang

    2011-01-01

    The correlation network of neurons emerges as an important mathematical framework for a spectrum of applications including neural modeling, brain disease prediction and brain-machine interface. However, construction of correlation network is computationally expensive, especially when the number of neurons is large and this prohibits realtime applications. This paper proposes a hardware architecture using hierarchical systolic arrays to reconstruct the correlation network. Through mapping an efficient algorithm for cross-correlation onto a massively parallel structure, the hardware can accomplish the network construction with extremely small delay. The proposed structure is evaluated using Field Programmable Gate Array (FPGA). Results show that our method is three orders of magnitudes faster than the software approach using desktop computer. This new method enables real-time network construction and leads to future novel devices of realtime neuronal network monitoring and rehabilitation.

  5. An unusual presentation of atrial myxoma

    PubMed Central

    Anpalakhan, Shaemala; Ramasamy, Dewi; Fan, Kin Sing

    2014-01-01

    Myxomas are uncommon primary cardiac tumours that usually affect the left atrium. We herein report the case of a patient who presented with right heart failure and proteinuria, leading to the diagnosis of atrial myxoma. Surgical resection resulted in resolution of the patient’s symptoms. PMID:25631903

  6. Spinal cord ischemia and left atrial myxoma.

    PubMed

    Hirose, G; Kosoegawa, H; Takado, M; Shimazaki, K; Murakami, E

    1979-07-01

    A 62-year-old man had an acute, transient, flaccid paraplegia. Examination showed a primary cardiac tumor with emboli to major branches of the aorta. A myxoma was removed from the left atrium, and normal function returned. Left atrial myxoma should be suspected as a cause for embolism to the CNS.

  7. Atrial and ventricular tachyarrhythmias in military personnel.

    PubMed

    Posselt, Bonnie N; Cox, A T; D'Arcy, J; Rooms, M; Saba, M

    2015-09-01

    Although rare, sudden cardiac death does occur in British military personnel. In the majority of cases, the cause is considered to be a malignant ventricular tachyarrhythmia, which can be precipitated by a number of underlying pathologies. Conversely, a tachyarrhythmia may have a more benign and treatable cause, yet the initial clinical symptoms may be similar, making differentiation difficult. This is an overview of the mechanisms underlying the initiation and propagation of arrhythmias and the various pathological conditions that predispose to arrhythmia genesis, classified according to which parts of the heart are involved: atrial tachyarrhythmias, atrial and ventricular, as well as those affecting the ventricles alone. It encompasses atrial tachycardia, atrial flutter, supraventricular tachycardias and ventricular tachycardias, including the more commonly encountered inherited primary electrical diseases, also known as the channelopathies. The clinical features, investigation and management strategies are outlined. The occupational impact-in serving military personnel and potential recruits-is described, with explanations relating to the different conditions and their specific implication on continued military service.

  8. Obstructive Sleep Apnea and Atrial Arrhythmogenesis

    PubMed Central

    Hohl, Mathias; Linz, Benedikt; Böhm, Michael; Linz, Dominik

    2014-01-01

    Atrial fibrillation (AF) is the most common sustained arrhythmia and is associated with relevant morbidity and mortality. Besides hypertension, valvular disease and cardiomyopathy, mainly ischemic and dilated, also other conditions like obesity, alcohol abusus, genetic factors and obstructive sleep apnea (OSA) are discussed to contribute to the progression from paroxysmal to persistent AF. The prevalence of OSA among patients with AF is 40-50%. OSA is characterized by periodic or complete cessation of effective breathing during sleep due to obstruction of the upper airways. Obstructive respiratory events result in acute intrathoracic pressure swings and profound changes in blood gases together leading to atrial stretch and acute sympatho-vagal dysbalance resulting in acute apnea related to electrophysiological and hemodynamic alterations. Additionally, repetitive obstructive events in patients with OSA may lead to sympathetic and neurohumoral activation and subsequent structural and functional changes in the atrium creating an arrhythmogenic substrate for AF in the long run. This review focuses on the acute and chronic effects of negative thoracic pressure swings, changes in blood pressure and sympatho-vagal dysbalance induced by obstructive respiratory events on atrial electrophysiology and atrial structure in patients with obstructive sleep apnea. PMID:25004989

  9. Atrial fibrillation pacing decreases intravascular shear stress in a New Zealand white rabbit model: implications in endothelial function.

    PubMed

    Jen, Nelson; Yu, Fei; Lee, Juhyun; Wasmund, Steve; Dai, Xiaohu; Chen, Christina; Chawareeyawong, Pai; Yang, Yongmo; Li, Rongsong; Hamdan, Mohamed H; Hsiai, Tzung K

    2013-08-01

    Atrial fibrillation (AF) is characterized by multiple rapid and irregular atrial depolarization, leading to rapid ventricular responses exceeding 100 beats per minute (bpm). We hypothesized that rapid and irregular pacing reduced intravascular shear stress (ISS) with implication to modulating endothelial responses. To simulate AF, we paced the left atrial appendage of New Zealand White rabbits (n = 4) at rapid and irregular intervals. Surface electrical cardiograms were recorded for atrial and ventricular rhythm, and intravascular convective heat transfer was measured by microthermal sensors, from which ISS was inferred. Rapid and irregular pacing decreased arterial systolic and diastolic pressures (baseline, 99/75 mmHg; rapid regular pacing, 92/73; rapid irregular pacing, 90/68; p < 0.001, n = 4), temporal gradients ([Formula: see text] from 1,275 ± 80 to 1,056 ± 180 dyne/cm(2) s), and reduced ISS (from baseline at 32.0 ± 2.4 to 22.7 ± 3.5 dyne/cm(2)). Computational fluid dynamics code demonstrated that experimentally inferred ISS provided a close approximation to the computed wall shear stress at a given catheter to vessel diameter ratio, shear stress range, and catheter position. In an in vitro flow system in which time-averaged shear stress was maintained at [Formula: see text] , we further demonstrated that rapid pulse rates at 150 bpm down-regulated endothelial nitric oxide, promoted superoxide (O 2 (.-) ) production, and increased monocyte binding to endothelial cells. These findings suggest that rapid pacing reduces ISS and [Formula: see text] , and rapid pulse rates modulate endothelial responses.

  10. Azilsartan medoxomil plus chlorthalidone reduces blood pressure more effectively than olmesartan plus hydrochlorothiazide in stage 2 systolic hypertension.

    PubMed

    Cushman, William C; Bakris, George L; White, William B; Weber, Michael A; Sica, Domenic; Roberts, Andrew; Lloyd, Eric; Kupfer, Stuart

    2012-08-01

    Azilsartan medoxomil, an effective, long-acting angiotensin II receptor blocker, is a new treatment for hypertension that is also being developed in fixed-dose combinations with chlorthalidone, a potent, long-acting thiazide-like diuretic. We compared once-daily fixed-dose combinations of azilsartan medoxomil/chlorthalidone force titrated to a high dose of either 40/25 mg or 80/25 mg with a fixed-dose combination of the angiotensin II receptor blocker olmesartan medoxomil plus the thiazide diuretic hydrochlorothiazide force titrated to 40/25 mg. The design was a randomized, 3-arm, double-blind, 12-week study of 1071 participants with baseline clinic systolic blood pressure 160 to 190 mm Hg and diastolic blood pressure ≤119 mm Hg. Patients had a mean age of 57 years; 59% were men, 73% were white, and 22% were black. At baseline, mean clinic blood pressure was 165/96 mm Hg and 24-hour mean blood pressure was 150/88 mm Hg. Changes in clinic (primary end point) and ambulatory systolic blood pressures at week 12 were significantly greater in both azilsartan medoxomil/chlorthalidone arms than in the olmesartan/hydrochlorothiazide arm (P<0.001). Changes in clinic systolic blood pressure (mean±SE) were -42.5±0.8, -44.0±0.8, and -37.1±0.8 mm Hg, respectively. Changes in 24-hour ambulatory systolic blood pressure were -33.9±0.8, -36.3±0.8, and -27.5±0.8 mm Hg, respectively. Adverse events leading to permanent drug discontinuation occurred in 7.9%, 14.5%, and 7.1% of the groups given azilsartan medoxomil/chlorthalidone 40/25 mg, azilsartan medoxomil/chlorthalidone 80/25 mg, and olmesartan/hydrochlorothiazide 40/25 mg, respectively. This large, forced-titration study has demonstrated superior antihypertensive efficacy of azilsartan medoxomil/chlorthalidone fixed-dose combinations compared with the maximum approved dose of olmesartan/hydrochlorothiazide.

  11. Doppler echocardiographic parameters of evaluation of left ventricular systolic function.

    PubMed

    Drăgulescu, S I; Roşu, D; Abazid, J; Ionac, A

    1993-01-01

    The authors suggest a new method using Doppler echocardiography for the evaluation of cardiac performance. Doppler echocardiography permits the calculation of left ventricular (LV) ejection force (according to Newton's second law of motion). The ejection force was calculated in 36 patients with heart failure subgrouped into 3 groups based on ejection fraction (EF) (> 60%; 41-60%; < 40%) compared to 11 normal subjects. The LV ejection force showed a good linear correlation with LV ejection fraction (r = 0.86). Data of the study suggest that the LV ejection force is a valuable and accurate index for the assessment of cardiac performance, especially in early stages of disease.

  12. Stroke as the First Manifestation of Atrial Fibrillation

    PubMed Central

    Jaakkola, Jussi; Mustonen, Pirjo; Kiviniemi, Tuomas; Hartikainen, Juha E. K.; Palomäki, Antti; Hartikainen, Päivi; Nuotio, Ilpo; Ylitalo, Antti; Airaksinen, K. E. Juhani

    2016-01-01

    Atrial fibrillation may remain undiagnosed until an ischemic stroke occurs. In this retrospective cohort study we assessed the prevalence of ischemic stroke or transient ischemic attack as the first manifestation of atrial fibrillation in 3,623 patients treated for their first ever stroke or transient ischemic attack during 2003–2012. Two groups were formed: patients with a history of atrial fibrillation and patients with new atrial fibrillation diagnosed during hospitalization for stroke or transient ischemic attack. A control group of 781 patients with intracranial hemorrhage was compiled similarly to explore causality between new atrial fibrillation and stroke. The median age of the patients was 78.3 [13.0] years and 2,009 (55.5%) were women. New atrial fibrillation was diagnosed in 753 (20.8%) patients with stroke or transient ischemic attack, compared to 15 (1.9%) with intracranial hemorrhage. Younger age and no history of coronary artery disease or other vascular diseases, heart failure, or hypertension were the independent predictors of new atrial fibrillation detected concomitantly with an ischemic event. Thus, ischemic stroke was the first clinical manifestation of atrial fibrillation in 37% of younger (<75 years) patients with no history of cardiovascular diseases. In conclusion, atrial fibrillation is too often diagnosed only after an ischemic stroke has occurred, especially in middle-aged healthy individuals. New atrial fibrillation seems to be predominantly the cause of the ischemic stroke and not triggered by the acute cerebrovascular event. PMID:27936187

  13. Systolic Blood Pressure Accuracy Enhancement in the Electronic Palpation Method Using Pulse Waveform

    DTIC Science & Technology

    2007-11-02

    1 of 4 SYSTOLIC BLOOD PRESSURE ACCURACY ENHANCEMENT IN THE ELECTRONIC PALPATION METHOD USING PULSE WAVEFORM H. S. S. Sorvoja1, R. A. Myllylä1...systolic blood pressure measurements based on pulse waveform. A set of measurement was carried out with elderly cardiac surgery patients. The experiments... blood pressure . Systolic pressure errors were defined and correlations with other specific values, like pressure rise time, pulse wave velocity

  14. Endurance sport practice as a risk factor for atrial fibrillation and atrial flutter.

    PubMed

    Mont, Lluís; Elosua, Roberto; Brugada, Josep

    2009-01-01

    Although the benefits of regular exercise in controlling cardiovascular risk factors have been extensively proven, little is known about the long-term cardiovascular effects of regular and extreme endurance sport practice, such as jogging, cycling, rowing, swimming, etc. Recent data from a small series suggest a relationship between regular, long-term endurance sport practice and atrial fibrillation (AF) and flutter. Reported case control studies included less than 300 athletes, with mean age between 40 and 50. Most series recruited only male patients, or more than 70% males, who had been involved in intense training for many years. Endurance sport practice increases between 2 and 10 times the probability of suffering AF, after adjusting for other risk factors. The possible mechanisms explaining the association remain speculative. Atrial ectopic beats, inflammatory changes, and atrial size have been suggested. Some of the published studies found that atrial size was larger in athletes than in controls, and this was a predictor for AF. It has also been shown that the left atrium may be enlarged in as many as 20% of competitive athletes. Other proposed mechanisms are increased vagal tone and bradycardia, affecting the atrial refractory period; however, this may facilitate rather than cause the arrhythmia. In summary, recent data suggest an association between endurance sport practice and atrial fibrillation and flutter. The underlying mechanism explaining this association is unclear, although structural atrial changes (dilatation and fibrosis) are probably present. Larger longitudinal studies and mechanistic studies are needed to further characterize the association to clarify whether a threshold limit for the intensity and duration of physical activity may prevent AF, without limiting the cardiovascular benefits of exercise.

  15. Effectiveness of Early Invasive Therapy for Atrial Tachycardia in Adult Atrial-Baffle Survivors

    PubMed Central

    Zaidi, Ali N.; Morrison, Justin; Daniels, Curt J.; Kalbfleisch, Steven; Kertesz, Naomi J.

    2017-01-01

    Adults who underwent complex atrial baffling as children via Mustard or Senning procedures are at heightened risk for atrial arrhythmias. Antiarrhythmic therapies are typically ineffective in this population. Accordingly, our team of pediatric and adult electrophysiologists investigated the effectiveness of early invasive transbaffle-access techniques to perform early radiofrequency ablation at the source of these clinically significant arrhythmias. For this retrospective study, we selected 11 adult survivors of atrial baffling (mean age, 34 ± 9 yr) who underwent clinically indicated electrophysiologic study after no more than one trial of antiarrhythmic therapy. Using transbaffle-access techniques and 3-dimensional mapping of the venous atria, we found 12 inducible arrhythmias in 10 patients: intra-atrial reentrant tachycardia (n=6), atrioventricular nodal reentrant tachycardia (n=3), focal atrial tachycardia (n=2), and repetitive double firing of the atrioventricular node (n=1). Defining success as short- and midterm freedom from arrhythmia, we analyzed outcomes of radiofrequency ablation at 1 and 6 months. At 1 month, ablation was 100% successful. At 6 months, after 11 ablations in 9 patients, 5 patients had no clinical recurrence, 2 had improved arrhythmia control from minimal medical therapy, and 2 were to undergo repeat study for recurrent tachycardia. In the recurrence-free patients, arrhythmias during electrophysiology study matched the types found clinically before the study. To our knowledge, this is the largest one-year cohort of adult survivors of atrial baffling to have undergone study by a combined pediatric–adult electrophysiology team. We conclude that early invasive transbaffle access for ablating diverse atrial tachyarrhythmias was effective in these patients. PMID:28265208

  16. [Differences in atrial remodelling between right and left atria in patients with chronic atrial fibrillation].

    PubMed

    Tamargo Menéndez, Juan

    2011-01-01

    Atrial fibrillation starts in the left atrium and from there the activity invades the atrial tissues and causes an inhomogeneous shortening the duration of atrial action potential duration and refractoriness. The purpose of this study was to compare the voltage-dependent potassium currents in human cells isolated from the right and left atria and to determine whether electrical remodeling produced by chronic atrial fibrillation (CAF) differentially affects voltage-dependent potassium currents involved in atrial repolarization in each atrium as compared to sinus rhythm (SR). The currents were recorded using the whole-cell configuration of the patch-clamp technique. We found that in atrial cardiomyocytes of patients both in SR and in CAF there are three types of cells according to their main voltage-dependent repolarizing potassium current: the Ca(2+)-independent 4-aminopyridine sensitive component of the transient outward current (I(to1)) and the ultrarapid (I(Kur)), rapid (I(Kr)) and slow (I(Ks)) components of the delayed rectifier current. CAF differentially modified the proportion of these 3 types of cells on each atrium: CAF reduced the I(to1) more markedly in the left than in the right atria, while I(Kur) was more markedly reduced in the right than in the left atria. Interestingly, in both atria, CAF markedly increased the I(Ks). This increase was enhanced by isoproterenol and suppressed by atenolol. These changes produce a non-uniform shortening of atrial repolarization that facilitates the reentry of the cardiac impulse and the perpetuation of the arrhythmia.

  17. [Left ventricular systolic function: how to understand it and analyze it].

    PubMed

    Fernández-Pérez, G C; Franco López, A; García Fernández, M Á; Corral de la Calle, M Á; Encinas de la Iglesia, J; Velasco Casares, M

    2014-01-01

    In cardiac magnetic resonance imaging studies, left ventricular systolic function is usually calculated automatically. To understand and interpret parameters of left ventricular systolic function correctly, it is fundamental to understand how each parameter is obtained and why values obtained with different techniques, for example, ultrasonography and magnetic resonance imaging, can differ. This article provides details about the usual analysis of systolic function from the quantitative and qualitative points of view; it also explains other methods that do not require specific software. Moreover, we provide a file that we designed for use with Microsoft Excel(®) to enable simple, intuitive analysis of systolic function. Readers can use this file freely.

  18. Calcium-ion movement and contractility in atrial strips of frog heart are not affected by low-frequency-modulated, 1 GHz electromagnetic radiation.

    PubMed

    Schwartz, J L; Mealing, G A

    1993-01-01

    Calcium efflux from electrically stimulated, 45Ca(2+)-preloaded atrial strips of the frog heart was measured from samples of the rinsing perfusate collected at 2-min intervals for 32 min in a continuous perfusion chamber. Contractile force was simultaneously monitored. The specimen chamber was located in a stripline apparatus in which the atrial strips were exposed for 32 min to constant (CW) or amplitude-modulated (AM), 1 GHz electromagnetic (EM) fields at specific absorption rates (SAR) ranging from 3.2 microW/kg to 1.6 W/kg. Amplitude modulation was either at 0.5 Hz, in synchrony with the electrical stimulus applied to the preparation, or at 16 Hz. Neither unmodulated nor 0.5 Hz or 16 Hz modulated 1 GHz waves affected the movement of calcium ions or the contractile force in isolated atrial strips of the frog heart.

  19. 78 FR 11207 - Clinical Study Designs for Surgical Ablation Devices for Treatment of Atrial Fibrillation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-15

    ... Treatment of Atrial Fibrillation; Guidance for Industry and Food and Drug Administration Staff; Availability... Ablation Devices for Treatment of Atrial Fibrillation.'' This guidance provides FDA's recommendations on clinical trial designs for surgical ablation devices intended for the treatment of atrial...

  20. Analysis of real-time three dimensional transesophageal echocardiography in the assessment of left atrial appendage function in patients with atrial fibrillation

    PubMed Central

    Gan, Lin; Yu, Lan; Xie, Manying; Feng, Wei; Yin, Jiabao

    2016-01-01

    The aim of the study was to examine changes in left atrial appendage volume (LAA-V) in patients with non-valvular atrial fibrillation (AF) using real-time three-dimensional transesophageal echocardiography (RT3D-TEE) and evaluate the prediction value on the high risk of thrombosis of LAA. Using RT3D-TEE we measured: i) LAA peak empty velocity (LAA-PEV), ii) LAA-V including LAA end-diastolic volume (LAA-EDV) and end-systolic volume (LAA-ESV). We also calculated LAA ejection fraction (LAA-EF). RT3D-TEE was applied in 20 control cases and 74 patients with non-valvular AF. According to the presence of thrombosis, 74 patients were divided into the no thrombosis group (NTH group, n=52) and thrombosis group (TH group, n=22). Our results showed that there were significant differences in LAA-V and LAA-EF values in different groups (P<0.05). LAA-EDV moderately correlated with LAA-PEV (r=−0.531, P<0.001) while LAA-ESV demonstrated a strong correlation with LAA-PEV (r=−0.741, P<0.001). LAA-EF also showed a strong correlation with LAA-PEV (r=0.693, P<0.001). Through receiver operating characteristic (ROC) curves, the cut-off values of LAA-EDV and LAA-ESV in thrombosis of LAA were 18.45 and 9.69 ml, respectively. RT3D-TEE effectively evaluated the LAA-V, LAA-PEV and LAA-EF parameters, and proved to be valuable in the process of evaluation of thrombosis of LAA. PMID:27882157

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

    PubMed

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

    2014-01-01

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

  2. Atrial Myxoma in a Patient with Hypertrophic Cardiomyopathy

    PubMed Central

    Abdou, Mahmoud; Hayek, Salim; Williams, Byron R.

    2013-01-01

    Atrial myxoma is the most common primary cardiac tumor. Patients with atrial myxoma typically present with obstructive, embolic, or systemic symptoms; asymptomatic presentation is very rare. To our knowledge, isolated association of atrial myxoma with hypertrophic cardiomyopathy has been reported only once in the English-language medical literature. We report the case of an asymptomatic 71-year-old woman with known hypertrophic cardiomyopathy in whom a left atrial mass was incidentally identified on cardiac magnetic resonance images. After surgical excision of the mass and partial excision of the left atrial septum, histopathologic analysis confirmed the diagnosis of atrial myxoma. The patient was placed on preventive implantable cardioverter-defibrillator therapy and remained asymptomatic. The management of asymptomatic cardiac myxoma is a topic of debate, because no reports definitively favor either conservative or surgical measures. PMID:24082380

  3. Left atrial appendage mass: is it always a thrombus?

    PubMed Central

    Guler, Adem; Kurkluoglu, Mustafa; Yesil, Fahri Gurkan; Tavlasoglu, Murat; Cingoz, Faruk

    2016-01-01

    Myxoma is the most common benign tumor of the heart, but it is very rare for it to originate from the left atrial appendage. Distinguishing between a mass, a thrombus, and a tumor in the body of the left atrium with preoperative transthoracic or transesophageal echocardiography is very difficult, even more so in patients with mitral valve disease and chronic atrial fibrillation. A 50-year-old male patient was admitted for surgery with the diagnosis of mitral stenosis and chronic atrial fibrillation. Transesophageal echocardiography demonstrated a mass attached to the wall of the left atrial appendage. Histopathological examination of the mass showed an image compatible with a myxoma. We hereby describe a case of a left atrial appendage myxoma mimicking a left atrial appendage thrombus. PMID:28096835

  4. Unusual case of right atrial reinfarction.

    PubMed

    Radojevic, Nemanja; Savic, Slobodan; Aleksic, Vuk; Cukic, Dragana

    2012-02-01

    It is well known that atrial infarctions are rare comparing to the ventricular. They cannot easily be verified on ECG and the standard autopsy technique does not include a detailed review of the atrial wall, so the atrial infarction often remains undiagnosed. A 63-year-old male was treated and died in an intensive care unit due to decompensated liver insufficiency and cardiac disease following long-lasting alcohol abuse. At autopsy, the extreme cardiomegaly was found, severe atherosclerosis of the anterior descending branch of left coronary artery. The posterior wall of the right atrium was thickened (cca 9 mm) in diameter of cca 3 × 3 cm, and this area was yellowish in the luminal part, while the central part was filled with dark red blood. A detailed dissection of the coronary arteries showed the complete occlusion of the atrial branch of the right coronary artery wreath as far as the place of sinoatrial artery branching, which corresponded anatomically to the described area of infarction on the posterior wall of the right atrium. Histopathological examination of the previously described area of the posterior wall of the right atrium, showed four zones of heart muscle changes: 1. zone of partially preserved structure of the heart muscle, 2. zone of cellular (immature) connective tissue, 3. areas of bleeding in cellular connective tissue, and 4. zone of acellular (old) connective tissue. These histopathological changes indicated that the posterior wall of the right atrium was affected by myocardial necrosis in at least two and possibly more times. It is reasonable to think that bleeding in the third zone of the posterior wall of the right atrium contributed greatly to the death due to the anatomical proximity to the sinoatrial node. It was confirmed by the existence of bradycardia with a prolonged PR interval, PR segment elevation in D1 and aVL lead and PR depression in the D3 lead on the ECG. These ECG changes appeared immediately before asystolia and the

  5. Radiofrequency Ablation of Persistent Atrial Fibrillation

    PubMed Central

    Hussein, Ayman A.; Saliba, Walid I.; Barakat, Amr; Bassiouny, Mohammed; Chamsi-Pasha, Mohammed; Al-Bawardy, Rasha; Hakim, Ali; Tarakji, Khaldoun; Baranowski, Bryan; Cantillon, Daniel; Dresing, Thomas; Tchou, Patrick; Martin, David O.; Varma, Niraj; Bhargava, Mandeep; Callahan, Thomas; Niebauer, Mark; Kanj, Mohamed; Chung, Mina; Natale, Andrea; Lindsay, Bruce D.; Wazni, Oussama M.

    2017-01-01

    Background Various ablation strategies of persistent atrial fibrillation (PersAF) have had disappointing outcomes, despite concerted clinical and research efforts, which could reflect progressive atrial fibrillation–related atrial remodeling. Methods and Results Two-year outcomes were assessed in 1241 consecutive patients undergoing first-time ablation of PersAF (2005–2012). The time intervals between the first diagnosis of PersAF and the ablation procedures were determined. Patients had echocardiograms and measures of B-type natriuretic peptide and C-reactive protein before the procedures. The median diagnosis-to-ablation time was 3 years (25th–75th percentiles 1–6.5). With longer diagnosis-to-ablation time (based on quartiles), there was a significant increase in recurrence rates in addition to an increase in B-type natriuretic peptide levels (P=0.01), C-reactive protein levels (P<0.0001), and left atrial size (P=0.03). The arrhythmia recurrence rates over 2 years were 33.6%, 52.6%, 57.1%, and 54.6% in the first, second, third, and fourth quartiles, respectively (Pcategorical<0.0001). In Cox Proportional Hazard analyses, B-type natriuretic peptide levels, C-reactive protein levels, and left atrial size were associated with arrhythmia recurrence. The diagnosis-to-ablation time had the strongest association with the ablation outcomes which persisted in multivariable Cox analyzes (hazard ratio for recurrence per +1Log diagnosis-to-ablation time 1.27, 95% confidence interval 1.14–1.43; P<0.0001; hazard ratio fourth versus first quartile 2.44, 95% confidence interval 1.68–3.65; Pcategorical<0.0001). Conclusions In patients with PersAF undergoing ablation, the time interval between the first diagnosis of PersAF and the catheter ablation procedure had a strong association with the ablation outcomes, such as shorter diagnosis-to-ablation times were associated with better outcomes and in direct association with markers of atrial remodeling. PMID:26763227

  6. Inter-Subject Variability in Human Atrial Action Potential in Sinus Rhythm versus Chronic Atrial Fibrillation

    PubMed Central

    Sánchez, Carlos; Bueno-Orovio, Alfonso; Wettwer, Erich; Loose, Simone; Simon, Jana; Ravens, Ursula; Pueyo, Esther; Rodriguez, Blanca

    2014-01-01

    Aims Human atrial electrophysiology exhibits high inter-subject variability in both sinus rhythm (SR) and chronic atrial fibrillation (cAF) patients. Variability is however rarely investigated in experimental and theoretical electrophysiological studies, thus hampering the understanding of its underlying causes but also its implications in explaining differences in the response to disease and treatment. In our study, we aim at investigating the ability of populations of human atrial cell models to capture the inter-subject variability in action potential (AP) recorded in 363 patients both under SR and cAF conditions. Methods and Results Human AP recordings in atrial trabeculae (n = 469) from SR and cAF patients were used to calibrate populations of computational SR and cAF atrial AP models. Three populations of over 2000 sampled models were generated, based on three different human atrial AP models. Experimental calibration selected populations of AP models yielding AP with morphology and duration in range with experimental recordings. Populations using the three original models can mimic variability in experimental AP in both SR and cAF, with median conductance values in SR for most ionic currents deviating less than 30% from their original peak values. All cAF populations show similar variations in GK1, GKur and Gto, consistent with AF-related remodeling as reported in experiments. In all SR and cAF model populations, inter-subject variability in IK1 and INaK underlies variability in APD90, variability in IKur, ICaL and INaK modulates variability in APD50 and combined variability in Ito and IKur determines variability in APD20. The large variability in human atrial AP triangulation is mostly determined by IK1 and either INaK or INaCa depending on the model. Conclusion Experimentally-calibrated human atrial AP models populations mimic AP variability in SR and cAF patient recordings, and identify potential ionic determinants of inter-subject variability in

  7. A prospective randomized study to assess the efficacy of rate and site of atrial pacing on long-term development of atrial fibrillation.

    PubMed

    Lau, Chu-Pak; Wang, Chun-Chieh; Ngarmukos, Tachapong; Kim, You-Ho; Kong, Chi-Woon; Omar, Razali; Sriratanasathavorn, Charn; Munawar, Muhammad; Kam, Ruth; Lee, Kathy Lf; Lau, Elizabeth Oi-Yan; Tse, Hung-Fat

    2009-09-01

    The Septal Pacing for Atrial Fibrillation Suppression Evaluation (SAFE) study is a single-blinded, parallel randomized designed multicenter study in pacemaker indicated patients with paroxysmal atrial fibrillation (AF). The objective is to evaluate whether the site of atrial pacing--conventional right atrial appendage versus low atrial septal--with or without atrial overdrive pacing will influence the development of persistent AF. The study will provide a definitive answer to whether a different atrial pacing site or the use of AF suppression pacing or both can give incremental antiarrhythmic benefit when one is implanting a device for a patient with a history of paroxysmal AF.

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

    PubMed Central

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

    2017-01-01

    Remodelling in the atria could appear as a result of hypertension, diabetes or ischaemic heart disease. Galectin-3 (Gal-3) is a mediator of profibrotic pathways and a potential biomarker of cardiac remodelling. We prospectively recruited consecutive patients undergoing elective cardiac surgery. Preoperative Gal-3 levels were determined from serum samples, and the presence of fibrosis was assessed from atrial appendage tissue samples obtained during cardiac surgery. We included 100 patients with aortic valve or ischaemic heart diseases and 15 controls with permanent AF. Gal-3 levels were associated with sex, left atrial volume, previous cardiac disease, diabetes mellitus, hypertension, NYHA and NT-proBNP. We observed differences in serum Gal-3 concentrations between patients and controls with permanent AF (p = 0.020). We performed ROC curves related to fibrosis and established a cutoff point for Gal-3 >13.65 ng/ml. Multivariate analyses showed previous cardiac disease, NYHA scale and high Gal-3 to be independent predictors of fibrosis. After adjustment for confounding factors, atrial fibrosis remained the only independent factor for the development of AF (p = 0.022). High Gal-3 serum levels predict fibrosis of the atrial appendage. NYHA scale and previous cardiac disease were also associated with tissue fibrosis in patients undergoing surgery. Atrial fibrosis was the only independent predictor for post-operative AF occurrence in our model after correcting for confounding factors. PMID:28079145

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

    PubMed

    Matějková, Adéla; Šteiner, Ivo

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

  10. The role of left atrial receptors in the diuretic response to left atrial distension

    PubMed Central

    Ledsome, J. R.; Linden, R. J.

    1968-01-01

    1. The diuretic response to distension of the whole left atrium caused by obstruction of the mitral orifice has been compared with the effects of distension (by means of small balloons) of the left pulmonary vein/left atrial junctions. 2. Distension of the pulmonary vein/atrial junctions caused an increase in heart rate and a diuresis similar to but smaller than that caused by mitral obstruction. 3. Section of both ansae subclaviae prevented the increase in heart rate produced by distension of the pulmonary vein/left atrial junctions but had little effect on the diuretic response either to pulmonary vein distension or to mitral obstruction. 4. A diuretic response to mitral obstruction could be demonstrated after all nerves from the lungs had been cut but not after the vagus nerves had been cut at levels likely to interrupt the majority of afferent fibres from left atrial receptors. 5. The results support the view that stimulation of left atrial receptors is a major factor in the production of a diuretic response to mitral obstruction. PMID:5698283

  11. Energetic metabolism during acute stretch-related atrial fibrillation Shortened title: atrial fibrillation and metabolism

    PubMed Central

    Kalifa, J; Maixent, JM; Chalvidan, T; Dalmasso, C; Colin, D; Cozma, D; Laurent, P; Deharo, JC; Djiane, P; Cozzone, P; Bernard, M

    2010-01-01

    Background and methods Perturbations in energetic metabolism and impaired atrial contractility may play an important role in the pathogenesis of atrial fibrillation (AF). Besides, atrial stretch is commonly associated with AF. However, the atrial energetics of stretch-related AF are poorly understood. Here, we measured indicators of energy metabolism during acute-stretch related AF. PCr, adenine nucleotides and derivatives concentrations as well as the activity of the F0F1-ATPase and Na,K-ATPase were obtained after one hour of stretch and/or AF in isolated rabbit hearts and compared to control hearts without stretch and AF. Results After one hour of stretch-related AF, the total adenine nucleotides pool was significantly lower (42.2±2.6 versus 63.7±8.3 µmol/g protein in control group, p<0.05) and the PCr/ATP ratio significantly higher (2.3±0.3 vs 1.1± 0.1 in control group p<0.05), because of ATP, ADP and AMP decrease and PCr increase. The sum of high energy phosphate compounds did not change. There were no significant differences in F0F1-ATPase nor Na,K-ATPase activity between the groups. Conclusions Results show that in this experimental model, acute-stretch related AF induces specific modifications of atrial myocytes energetics that may play a pivotal role in the perpetuation of the arrhythmia. PMID:18553177

  12. Echocardiographic Evaluation of Changes in Cardiac Hemodynamics and Loading Conditions after Transthoracic Minimally Invasive Device Closure of Atrial Septal Defect

    PubMed Central

    Cao, Hua; Zhang, Gui-Can; Chen, Liang-Wan; Hu, Yun-Nan

    2015-01-01

    Purpose To evaluate transthoracic minimally invasive device closure of atrial septal defects by performing transthoracic echocardiography to measure changes in cardiac hemodynamics and loading conditions. Methods Between January 2012 and December 2012, we performed transthoracic minimally invasive device closure of atrial septal defects in 95 patients with secundum atrial septal defects (ASD), and performed transthoracic echocardiography to measure blood flow velocities at the tricuspid valve orifice and at the pulmonary valve orifice, sizes of the left and right atria and ventricles, right ventricular fractional area change, right ventricular Tei index, three-dimensional right ventricular ejection fraction, tricuspid annular plane systolic excursion and left ventricular ejection fractions before the procedure and 1 week, 3 months, and 1 year post-procedure. Results Varying degrees of improvement were observed post-procedure at later time points. The maximum blood flow velocity at the pulmonary valve orifice, mean flow velocity, velocity-time integral, and A peak and E peak blood flow velocity at the tricuspid valve orifice decreased significantly post-procedure (P<0.05). In 3 months and 1 year’s follow-up, the inner diameter of the middle portion of the pulmonary artery, and diameters of the right atrium and right ventricle decreased significantly post-procedure (P<0.05). The diameters of the left atrium and left ventricle increased after the procedure (P<0.05). One week after the procedure, the right ventricular fractional area change, three-dimensional right ventricular ejection fraction, right ventricular Tei index and tricuspid annular plane systolic excursion had significantly reduced compared with the preoperative data (P<0.05). While these four parameters were still decreased at the 3 months and at 1 year’s follow-up, but the differences were not statistically significant compared with the 1 week’s postoperative data (P>0.05). One week post

  13. Right ventricular systolic function is not the sole determinant of tricuspid annular motion.

    PubMed

    López-Candales, Angel; Rajagopalan, Navin; Saxena, Neil; Gulyasy, Beth; Edelman, Kathy; Bazaz, Raveen

    2006-10-01

    Maximal tricuspid annular plane systolic excursion (TAPSE) correlates well with right ventricular (RV) function; however, little is known regarding the impact of left ventricular (LV) systolic function on TAPSE. Consequently, TAPSE was examined in 206 patients (105 men; mean age 56 +/- 17 years), and the data were analyzed with respect to RV (RV fractional area change 45 +/- 19%) and LV (56 +/- 17%) systolic function. The mean TAPSE for the population studied was 1.97 +/- 0.72 cm. Although a strong linear correlation was noted between RV fractional area change and TAPSE (r = 0.73, p <0.0001), relative differences with regard to TAPSE were also found. First, the greatest TAPSE was noted only when RV and LV systolic function were normal (2.46 +/- 0.50 cm). Second, patients with reduced RV systolic function had the smallest TAPSE (1.28 +/- 0.48 cm, p <0.0001). Third, patients with normal RV function but reduced LV systolic function had TAPSE (1.91 +/- 0.54 cm, p <0.0001) that was intermediate between that of patients with normal RV and LV systolic function and those with abnormal RV systolic function. Fourth, patients with reduced biventricular function had the smallest TAPSE (1.16 +/- 0.41 cm, p <0.0001). In conclusion, TAPSE is not only determined by RV systolic function but also appears to depend on LV systolic function. TAPSE <2.0 cm is associated with some degree of either RV or LV dysfunction, whereas a value >2.0 cm suggests normal biventricular systolic function.

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

    PubMed Central

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

    2015-01-01

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

  15. Atrial fibrillation in hypertrophic cardiomyopathy: mechanisms, embolic risk and prognosis.

    PubMed

    Nair, Ajith G; Fischer, Avi G

    2006-12-01

    Hypertrophic cardiomyopathy (HCM) is associated with an increased incidence of supraventricular and ventricular arrhythmias. Atrial fibrillation (AF) is the most common arrhythmia in HCM with a prevalence of 20% and an annual incidence of two percent per year. Increased left atrial size and volume along with impaired left atrial function confer an increased likelihood of AF. The onset of AF is often accompanied by a decrease in functional status in conjunction with an increased risk of stroke and overall mortality.

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

    PubMed Central

    Singhi, Anil Kumar; Pradhan, Priya; Agarwal, Ravi; Sivakumar, Kothandum

    2016-01-01

    If the atrial appendages lie adjacent to each other on same side of the great arteries, instead of encircling their roots, they are referred as juxtaposed. Right juxtaposition of atrial appendages is less common than left juxtaposition. The images demonstrate the classical radiological, echocardiographic, and surgical images of juxtaposed atrial appendages. Their clinical incidence, associations, and relevance during interventional and surgical procedures are discussed. PMID:27212860

  17. Aorto-left atrial tunnel: a rare entity.

    PubMed

    Paul, Sajiv K; Gajjar, Trushar P; Desai, Neelam B

    2013-05-01

    Aorto-left atrial tunnel (ALAT) is a vascular channel that originates from 1 of the sinuses of Valsalva and terminates in the left atrium. The aorto-left atrial tunnel is an extremely rare anomaly. We describe here a case of congenital aorto-left atrial tunnel in a 4-year-old child who underwent successful surgical ligation with good immediate and early results.

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

    PubMed

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

    2015-01-01

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

  19. Relationship between early diastolic intraventricular pressure gradients, an index of elastic recoil, and improvements in systolic and diastolic function

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

    BACKGROUND: Early diastolic intraventricular pressure gradients (IVPGs) have been proposed to relate to left ventricular (LV) elastic recoil and early ventricular "suction." Animal studies have demonstrated relationships between IVPGs and systolic and diastolic indices during acute ischemia. However, data on the effects of improvements in LV function in humans and the relationship to IVPGs are lacking. METHODS AND RESULTS: Eight patients undergoing CABG and/or infarct exclusion surgery had a triple-sensor high-fidelity catheter placed across the mitral valve intraoperatively for simultaneous recording of left atrial (LA), basal LV, and apical LV pressures. Hemodynamic data obtained before bypass were compared with those with similar LA pressures and heart rates obtained after bypass. From each LV waveform, the time constant of LV relaxation (tau), +dP/dt(max), and -dP/dt(max) were determined. Transesophageal echocardiography was used to determined end-diastolic (EDV) and end-systolic (ESV) volumes and ejection fractions (EF). At similar LA pressures and heart rates, IVPG increased after bypass (before bypass 1.64+/-0.79 mm Hg; after bypass 2.67+/-1.25 mm Hg; P<0.01). Significant improvements were observed in ESV, as well as in apical and basal +dP/dt(max), -dP/dt(max), and tau (each P<0.05). Overall, IVPGs correlated inversely with both ESV (IVPG=-0.027[ESV]+3.46, r=-0.64) and EDV (IVPG=-0.027[EDV]+4.30, r=-0.70). Improvements in IVPGs correlated with improvements in apical tau (Deltatau =5.93[DeltaIVPG]+4.76, r=0.91) and basal tau (Deltatau =2.41[DeltaIVPG]+5.13, r=-0.67). Relative changes in IVPGs correlated with changes in ESV (DeltaESV=-0.97[%DeltaIVPG]+23.34, r=-0.79), EDV (DeltaEDV=-1.16[%DeltaIVPG]+34.92, r=-0.84), and EF (DeltaEF=0.38[%DeltaIVPG]-8.39, r=0.85). CONCLUSIONS: Improvements in LV function also increase IVPGs. These changes in IVPGs, suggestive of increases in LV suction and elastic recoil, correlate directly with improvements in LV relaxation

  20. Treatment of hypertension with perindopril reduces plasma atrial natriuretic peptide levels, left ventricular mass, and improves echocardiographic parameters of diastolic function

    NASA Technical Reports Server (NTRS)

    Yalcin, F.; Aksoy, F. G.; Muderrisoglu, H.; Sabah, I.; Garcia, M. J.; Thomas, J. D.

    2000-01-01

    BACKGROUND: Hypertension is a major independent risk factor for cardiac deaths, and diastolic dysfunction is a usual finding during the course of this disease. HYPOTHESIS: This study was designed to investigate the effects of chronic therapy with perindopril on left ventricular (LV) mass, left atrial size, diastolic function, and plasma level of atrial natriuretic peptide (ANP) in patients with hypertension. METHODS: Twenty four patients who had not been previously taking any antihypertensive medication and without prior history of angina pectoris, myocardial infarction, congestive heart failure, dysrhythmias, valvular heart disease, or systemic illnesses received 4-8 mg/day of perindopril orally. Echocardiographic studies were acquired at baseline and 6 months after the initiation of therapy. RESULTS: Systolic and diastolic blood pressure decreased from 174 +/- 19.7 and 107.5 +/- 7.8 mmHg to 134 +/- 10.6 and 82 +/- 6.7 mmHg, respectively (p < 0.001). Left ventricular mass decreased from 252.4 +/- 8.3 to 205.7 +/- 7.08 g and left atrial volume from 20.4 +/- 5.1 to 17.6 +/- 5.2 ml, respectively (p < 0.001). Transmitral Doppler early and atrial filling velocity ratio (E/A) increased from 0.69 +/- 0.06 to 0.92 +/- 0.05 m/s and plasma ANP level decreased from 71.9 +/- 11.7 to 35.3 +/- 7.8 pg/ml (p < 0.001). Reduction of LV mass correlated positively with a reduction in ANP levels (r = 0.66, p < 0.0005). CONCLUSIONS: Perindopril caused a significant reduction of LV mass, left atrial volume, and plasma ANP levels, as well as improvement in Doppler parameters of LV filling in this group of patients with hypertension.

  1. Automatic Identification of Systolic Time Intervals in Seismocardiogram

    NASA Astrophysics Data System (ADS)

    Shafiq, Ghufran; Tatinati, Sivanagaraja; Ang, Wei Tech; Veluvolu, Kalyana C.

    2016-11-01

    Continuous and non-invasive monitoring of hemodynamic parameters through unobtrusive wearable sensors can potentially aid in early detection of cardiac abnormalities, and provides a viable solution for long-term follow-up of patients with chronic cardiovascular diseases without disrupting the daily life activities. Electrocardiogram (ECG) and siesmocardiogram (SCG) signals can be readily acquired from light-weight electrodes and accelerometers respectively, which can be employed to derive systolic time intervals (STI). For this purpose, automated and accurate annotation of the relevant peaks in these signals is required, which is challenging due to the inter-subject morphological variability and noise prone nature of SCG signal. In this paper, an approach is proposed to automatically annotate the desired peaks in SCG signal that are related to STI by utilizing the information of peak detected in the sliding template to narrow-down the search for the desired peak in actual SCG signal. Experimental validation of this approach performed in conventional/controlled supine and realistic/challenging seated conditions, containing over 5600 heart beat cycles shows good performance and robustness of the proposed approach in noisy conditions. Automated measurement of STI in wearable configuration can provide a quantified cardiac health index for long-term monitoring of patients, elderly people at risk and health-enthusiasts.

  2. Detection of systolic ejection click using time growing neural network.

    PubMed

    Gharehbaghi, Arash; Dutoit, Thierry; Ask, Per; Sörnmo, Leif

    2014-04-01

    In this paper, we present a novel neural network for classification of short-duration heart sounds: the time growing neural network (TGNN). The input to the network is the spectral power in adjacent frequency bands as computed in time windows of growing length. Children with heart systolic ejection click (SEC) and normal children are the two groups subjected to analysis. The performance of the TGNN is compared to that of a time delay neural network (TDNN) and a multi-layer perceptron (MLP), using training and test datasets of similar sizes with a total of 614 normal and abnormal cardiac cycles. From the test dataset, the classification rate/sensitivity is found to be 97.0%/98.1% for the TGNN, 85.1%/76.4% for the TDNN, and 92.7%/85.7% for the MLP. The results show that the TGNN performs better than do TDNN and MLP when frequency band power is used as classifier input. The performance of TGNN is also found to exhibit better immunity to noise.

  3. Modeling systolic pressure variation due to positive pressure ventilation.

    PubMed

    Messerges, Joanne

    2006-01-01

    Although many clinical techniques have been proposed to assess blood volume none have been established as an undisputed standard practice, Volume studies suggest systolic pressure variation (SPV) as a promising volume indicator but underlying influences on SPV are not well understood. Successful modeling of SPV will reveal the major SPV influencers, guide algorithm development to accommodate these influencers, and potentially lead to a more clinically relevant interpretation of SPV values, thus improving upon current clinical methods for assessing blood volume. This study takes a first step towards identifying SPV influencers by investigating three variations of an existing pressure-flow cardiovascular model. Each successive version introduces an additional modification in attempt to model SPV under normovolemic and hypovolemic conditions, where the last model accounts for positive pressure ventilation, venous compression, and a rightward septum shift. Under normovolemic conditions, each model yields SPV values of 5.8, 6.4, and 6.7 mmHg, respectively. Under hypovolemic conditions the results do not agree with clinical findings, suggesting these three mechanisms alone do not dictate the clinical SPV response to a decrease in volume. Model results are used to suggest improvements for future work.

  4. Central Systolic Hypertension in Patients with Well-Controlled Hypertension

    PubMed Central

    Potočárová, Mária; Murín, Ján; Kozlíková, Katarína; Luha, Ján; Čaprnda, Martin

    2017-01-01

    Background. Central systolic blood pressure (CSBP) has prognostic significance and simplified devices for its estimation have been introduced recently. The aim of this study was to assess the achievement of the target CSBP in treated hypertensive patients. Subjects and Methods. One hundred patients with well-controlled hypertension were analysed. For CSBP estimation, we used the Arteriograph (TensioMed Ltd.), which uses one cuff for all measurements, the “single-point measurement” approach. Results. We found that 62% of patients had CSBP ≥ 130 mmHg, the suggested cut-off value for hypertension. When sex-specific classification was employed (CSBP ≥ 137 mmHg for female and CSBP ≥ 133 mmHg for male), only 13% of patients (mainly women) remained in the hypertensive range. We also found that 55% of patients had a CSBP higher than brachial pressure. Multiple analyses showed that CSBP was significantly associated with sex, height, and return time. Conclusions. A high proportion of treated hypertensive patients had CSBP levels that exceeded their brachial BP. CSBP positively correlated with lower height and shorter return time of the reflected pressure wave and was significantly higher in females compared to males. These findings suggest that, for CSBP classification, it is important to take height and sex-specific differences into account. PMID:28127560

  5. Automatic Identification of Systolic Time Intervals in Seismocardiogram

    PubMed Central

    Shafiq, Ghufran; Tatinati, Sivanagaraja; Ang, Wei Tech; Veluvolu, Kalyana C.

    2016-01-01

    Continuous and non-invasive monitoring of hemodynamic parameters through unobtrusive wearable sensors can potentially aid in early detection of cardiac abnormalities, and provides a viable solution for long-term follow-up of patients with chronic cardiovascular diseases without disrupting the daily life activities. Electrocardiogram (ECG) and siesmocardiogram (SCG) signals can be readily acquired from light-weight electrodes and accelerometers respectively, which can be employed to derive systolic time intervals (STI). For this purpose, automated and accurate annotation of the relevant peaks in these signals is required, which is challenging due to the inter-subject morphological variability and noise prone nature of SCG signal. In this paper, an approach is proposed to automatically annotate the desired peaks in SCG signal that are related to STI by utilizing the information of peak detected in the sliding template to narrow-down the search for the desired peak in actual SCG signal. Experimental validation of this approach performed in conventional/controlled supine and realistic/challenging seated conditions, containing over 5600 heart beat cycles shows good performance and robustness of the proposed approach in noisy conditions. Automated measurement of STI in wearable configuration can provide a quantified cardiac health index for long-term monitoring of patients, elderly people at risk and health-enthusiasts. PMID:27874050

  6. Isolated Systolic Hypertension in Young and Middle-Aged Adults.

    PubMed

    Yano, Yuichiro; Lloyd-Jones, Donald M

    2016-11-01

    Young and middle-aged adults (ages ≤50 years) are increasingly prone to stroke, kidney disease, and worsening cardiovascular disease (CVD) mortality. An alarming increase in the prevalence of high blood pressure (BP) may underlie the adverse trend. However, there is often uncertainty in BP management for young and middle-aged adults. Isolated systolic hypertension (ISH) is one such example. Whether ISH in young and middle-aged adults represents "pseudo" or "spurious" hypertension is still being debated. ISH in young and middle-aged adults is a heterogeneous entity; some individuals appear to have increased stroke volume, whereas others have stiffened aortae, or both. One size does not seem to fit all in the clinical management of ISH in young and middle-aged adults. Rather than treating ISH as a monolithic condition, detailed phenotyping of ISH based on (patho)physiology and in the context of individual global cardiovascular risks would seem to be most useful to assess an individual expected net benefit from therapy. This review provides an overview of the current understanding of ISH in young and middle-aged adults, including the prevalence, pathophysiology, and treatment.

  7. Coherex WAVECREST I Left Atrial Appendage Occlusion Study

    ClinicalTrials.gov

    2015-01-13

    Non-valvular Paroxysmal, Persistent, or Permanent Atrial Fibrillation; LAA Anatomy Amenable to Treatment by Percutaneous Technique; Anticoagulation Indication for Potential Thrombus Formation in the Left Atrium

  8. The role of myocardial wall thickness in atrial arrhythmogenesis.

    PubMed

    Whitaker, John; Rajani, Ronak; Chubb, Henry; Gabrawi, Mark; Varela, Marta; Wright, Matthew; Niederer, Steven; O'Neill, Mark D

    2016-12-01

    Changes in the structure and electrical behaviour of the left atrium are known to occur with conditions that predispose to atrial fibrillation (AF) and in response to prolonged periods of AF. We review the evidence that changes in myocardial thickness in the left atrium are an important part of this pathological remodelling process. Autopsy studies have demonstrated changes in the thickness of the atrial wall between patients with different clinical histories. Comparison of the reported tissue dimensions from pathological studies provides an indication of normal ranges for atrial wall thickness. Imaging studies, most commonly done using cardiac computed tomography, have demonstrated that these changes may be identified non-invasively. Experimental evidence using isolated tissue preparations, animal models of AF, and computer simulations proves that the three-dimensional tissue structure will be an important determinant of the electrical behaviour of atrial tissue. Accurately identifying the thickness of the atrial may have an important role in the non-invasive assessment of atrial structure. In combination with atrial tissue characterization, a comprehensive assessment of the atrial dimensions may allow prediction of atrial electrophysiological behaviour and in the future, guide radiofrequency delivery in regions based on their tissue thickness.

  9. Ebstein Anomaly With Right Atrial Clot

    PubMed Central

    Kumar, Prakash; Singhal, Gaurav; Sinha, Santosh Kumar; Pandey, Umeshwar; Thakur, Ramesh; Varma, Chandra Mohan

    2015-01-01

    Ebstein anomaly (EA) is a rare congenital malformation of the tricuspid valve (TV), often associated with other cardiac malformations, especially atrial septal defect/patent foramen ovale (PFO) which is present in 80-90% of patients and predisposes to paradoxical embolization. We describe the case of a 17-year-old female, who presented with worsening exertional dyspnea, fatigue and pedal edema and atrial fibrillation (AF). Transthoracic echocardiography showed EA with severely dilated right atrium (RA), small functional right ventricle (RV), low velocity flow across TV with spontaneous echo contrast and giant clot in RA. Fortunately for the patient, contrast and transesophageal echocardiography revealed an intact interatrial septum with no PFO preventing any paradoxical embolism from large clot in RA, more so in the background of AF. Important differential diagnosis of congenitally unguarded TV orifice was ruled out due to presence of septal and anterior leaflets of TV and associated chordae. PMID:28197250

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

    PubMed

    Ishii, Yosuke

    2013-01-01

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

  11. Effects of APD Dispersion on Atrial Reentry

    NASA Astrophysics Data System (ADS)

    Vigmond, Edward; Kuo, Samuel; Trayanova, Natalia

    2002-03-01

    Atrial fibrillation is the most common cardiac arrhythmia with dispersion of refractoriness being postulated as a mechanism promoting its formation. The distribution of action potential duration (APD) over the atria, however, remains unmapped under both normal and pathological conditions. The purpose of this computer study was to investigate how APD heterogenity interacts with morphological barriers to produce reentry. Reentries were first initiated in a 2D sheet of atrial tissue. The effects of incorporating APD heterogeneity and periodic boundary conditions, to better mimic physiological conditions, on reentry were ascertained. Analysis was extended to a morphologically realistic 3D model wherein several APD distributions were simulated. Comparisons between the 2D and 3D models demonstrated that the sheet behaviour was insufficient to capture the complex behaviour. Regional differences in APD, aided by anatomical barriers, were found to affect the formation and stabilization of reentrant circuits, as well as lead to the fractionation of wavefronts.

  12. [Atrial fibrillation ablation: application of nurse methodology].

    PubMed

    Ramos-González-Serna, Amelia; Mateos-García, M Dolores

    2011-01-01

    Ablation of pulmonary veins for treatment of atrial fibrillation involves applying radiofrequency energy wave by a catheter that causes a circumferential lesion to achieve electrical isolation and voltage drop in the interior. It is mainly applied when there is resistance to treatment and recurrence of symptoms affecting the quality of life of patients. The nurse is an important part of the multidisciplinary team who care for patients who undergo this procedure. The provision of comprehensive nursing care should include nursing procedures prior to, during, and after treatment to ensure the careful and systematic quality required. The aims of this article are: to provide specialised knowledge on the procedure of atrial fibrillation ablation, to describe the preparation of the electrophysiology laboratory, analyse nursing care and develop a standardized care plan for patients on whom this procedure is performed using the NANDA (North American Nursing Association) taxonomy and NIC (Nursing Intervention Classification).

  13. [Progress of anticoagulation therapy in atrial fibrillation].

    PubMed

    Hernández Olmedo, Miguel; Suárez Fernández, Carmen

    2015-08-07

    Atrial fibrillation is currently a very prevalent disease and it represents one of the most common causes of disabling stroke. Antithrombotic therapies have reduced the incidence of this complication although they pose many limitations and difficulties. As a result, a large number of high risk patients do not receive an appropriate treatment. In recent years, four new oral anticoagulants (NOAC) with relevant advantages in comparison to vitaminK antagonists have been released. Four large phaseiii clinical trials have demonstrated that NOAC are at least as safe and efficacious as warfarin in stroke prevention in non-valve atrial fibrillation patients with moderate-high thrombotic risk, being their main advantage the reduction in intracranial hemorrhage. The arrival of these drugs has caused great expectations in the management of these patients but also new doubts. Lacking data in some subgroups of frail patients, the absence of specific antidotes available and specially their high cost represent nowadays the main limitations for their generalization.

  14. Ebstein Anomaly With Right Atrial Clot.

    PubMed

    Kumar, Prakash; Singhal, Gaurav; Sinha, Santosh Kumar; Pandey, Umeshwar; Thakur, Ramesh; Varma, Chandra Mohan

    2015-10-01

    Ebstein anomaly (EA) is a rare congenital malformation of the tricuspid valve (TV), often associated with other cardiac malformations, especially atrial septal defect/patent foramen ovale (PFO) which is present in 80-90% of patients and predisposes to paradoxical embolization. We describe the case of a 17-year-old female, who presented with worsening exertional dyspnea, fatigue and pedal edema and atrial fibrillation (AF). Transthoracic echocardiography showed EA with severely dilated right atrium (RA), small functional right ventricle (RV), low velocity flow across TV with spontaneous echo contrast and giant clot in RA. Fortunately for the patient, contrast and transesophageal echocardiography revealed an intact interatrial septum with no PFO preventing any paradoxical embolism from large clot in RA, more so in the background of AF. Important differential diagnosis of congenitally unguarded TV orifice was ruled out due to presence of septal and anterior leaflets of TV and associated chordae.

  15. Lipid-altering therapy and atrial fibrillation.

    PubMed

    Bachmann, Justin M; Majmudar, Maulik; Tompkins, Christine; Blumenthal, Roger S; Marine, Joseph E

    2008-01-01

    Atrial fibrillation (AF) is a common cardiac arrhythmia with significant morbidity and public health cost. Because of limitations of efficacy and safety of conventional antiarrhythmic agents, alternative therapies for AF are needed. The potential antiarrhythmic properties of lipid-altering therapy, including the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors and fish oils, are increasingly recognized, particularly in light of their potential anti-inflammatory properties. This review examines the known effects of lipid-altering therapy on atrial arrhythmias in both experimental and clinical settings. Inflammatory states, such as post-cardiac surgery and AF of recent onset, show promise as targets. In contrast, lipid-lowering therapy is less likely to affect longstanding persistent AF. Current recommendations for the use of lipid-altering therapy for prevention and treatment of AF are summarized.

  16. Sequential Hybrid Procedure for Persistent Atrial Fibrillation

    PubMed Central

    Bulava, Alan; Mokracek, Ales; Hanis, Jiri; Kurfirst, Vojtech; Eisenberger, Martin; Pesl, Ladislav

    2015-01-01

    Background Catheter ablation of persistent atrial fibrillation yields an unsatisfactorily high number of failures. The hybrid approach has recently emerged as a technique that overcomes the limitations of both surgical and catheter procedures alone. Methods and Results We investigated the sequential (staged) hybrid method, which consists of a surgical thoracoscopic radiofrequency ablation procedure followed by radiofrequency catheter ablation 6 to 8 weeks later using the CARTO 3 mapping system. Fifty consecutive patients (mean age 62±7 years, 32 males) with long‐standing persistent atrial fibrillation (41±34 months) and a dilated left atrium (>45 mm) were included and prospectively followed in an unblinded registry. During the electrophysiological part of the study, all 4 pulmonary veins were found to be isolated in 36 (72%) patients and a complete box‐lesion was confirmed in 14 (28%) patients. All gaps were successfully re‐ablated. Twelve months after the completed hybrid ablation, 47 patients (94%) were in normal sinus rhythm (4 patients with paroxysmal atrial fibrillation required propafenone and 1 patient underwent a redo catheter procedure). The majority of arrhythmias recurred during the first 3 months. Beyond 12 months, there were no arrhythmia recurrences detected. The surgical part of the procedure was complicated by 7 (13.7%) major complications, while no serious adverse events were recorded during the radiofrequency catheter part of the procedure. Conclusions The staged hybrid epicardial–endocardial treatment of long‐standing persistent atrial fibrillation seems to be extremely effective in maintenance of normal sinus rhythm compared to radiofrequency catheter or surgical ablation alone. Epicardial ablation alone cannot guarantee durable transmural lesions. Clinical Trial Registration URL: www.ablace.cz Unique identifier: cz‐060520121617 PMID:25809548

  17. Atrial Fibrillation During an Exploration Class Mission

    NASA Technical Reports Server (NTRS)

    Lipset, Mark A.; Lemery, Jay; Polk, J. D.; Hamilton, Douglas R.

    2010-01-01

    Background: A long-duration exploration class mission is fraught with numerous medical contingency plans. Herein, we explore the challenges of symptomatic atrial fibrillation (AF) occurring during an exploration class mission. The actions and resources required to ameliorate the situation, including the availability of appropriate pharmaceuticals, monitoring devices, treatment modalities, and communication protocols will be investigated. Challenges of Atrial Fibrillation during an Exploration Mission: Numerous etiologies are responsible for the initiation of AF. On Earth, we have the time and medical resources to evaluate and determine the causative situation for most cases of AF and initiate therapy accordingly. During a long-duration exploration class mission resources will be severely restricted. How is one to determine if new onset AF is due to recent myocardial infarction, pulmonary embolism, fluid overload, thyrotoxicosis, cardiac structural abnormalities, or CO poisoning? Which pharmaceutical therapy should be initiated and what potential side effects can be expected? Should anti-coagulation therapy be initiated? How would one monitor the therapeutic treatment of AF in microgravity? What training would medical officers require, and which communication strategies should be developed to enable the best, safest therapeutic options for treatment of AF during a long-duration exploration class mission? Summary: These questions will be investigated with expert opinion on disease elucidation, efficient pharmacology, therapeutic monitoring, telecommunication strategies, and mission cost parameters with emphasis on atrial fibrillation being just one illustration of the tremendous challenges that face a long-duration exploration mission. The limited crew training time, medical hardware, and drugs manifested to deal with such an event predicate that aggressive primary and secondary prevention strategies be developed to protect a multibillion-dollar asset like the

  18. Atrial Fibrillation - Multiple Languages: MedlinePlus

    MedlinePlus

    ... sharing features on this page, please enable JavaScript. Arabic (العربية) Chinese - Simplified (简体中文) Chinese - Traditional (繁體中文) French ( ... Somali (af Soomaali) Spanish (español) Vietnamese (Tiếng Việt) Arabic (العربية) Atrial Fibrillation (Arabic) العربية Bilingual PDF Health ...

  19. [Non-pharmacologic treatment of atrial fibrillation].

    PubMed

    Csanádi, Zoltán; Fazekas, Tamás; Varró, András

    2003-06-29

    The authors provide an update on non-pharmacological treatment of atrial fibrillation (AF). They emphasize that although antiarrhythmic drugs continue to be first-line therapy for the arrhythmia considered to be a cardiovascular epidemic, clinical research to develop non-pharmacological means of treatment has been unprecedentally intensified during the last decade. Electrical cardioversion is the most successful non-pharmacological method to restore sinus rhythm, also the efficacy and safety of AV node ablation for palliative ventricular rate-controll is established. "Hybrid" therapeutic procedures, involving combinations of pharmacological and non-pharmacological interventions have gained widespread use. Curative transcatheter ablation for arrhythmia prevention is to be considered in case of clinical suggestions that AF is initiated by a primary regular arrhythmia that is amenable to routine catheter ablation (secondary AF). Despite encouraging results, at this point in time, curative catheter ablation for primary AF may offer significant improvement or even cure only for a small subset of patients, mostly young individuals with normal heart, and paroxysmal AF with frequent, symptomatic episodes refractory to multiple antiarrhythmic drugs. These interventions are to be performed in the settings of a clinical research project in some institutions. Regarding pacemaker therapy in case of bradycardia indication, physiologic pacing (AAI or DDD) is associated with significantly lower incidence of atrial fibrillation than ventricular pacing. Large-scale randomized controlled trials are needed to assess the clinical value of specially designed implantable devices to prevent atrial fibrillation in patients with no conventional bradycardia indication. Also, technical optimization and proper clinical evaluation is needed for implantable atrioverters and implantable cardioverter defibrillators capable of atrial cardioversion therapy.

  20. Predictive value of various Doppler-derived parameters of atrial conduction time for successful atrial fibrillation ablation

    PubMed Central

    Valtuille, Lucas; Choy, Jonathan B; Becher, Harald

    2015-01-01

    Various Doppler-derived parameters of left atrial electrical remodeling have been demonstrated to predict recurrence of atrial fibrillation (AF) after AF ablation. The aim of this study was to compare three Doppler-derived measures of atrial conduction time in patients undergoing AF ablation, and to investigate their predictive value for successful procedure. In 32 prospectively enrolled patients undergoing the first AF ablation, atrial conduction time was estimated by measuring the time delay between the onset of P-wave on the surface ECG to the peak of the a′-wave on the pulsed-wave Doppler and color-coded tissue Doppler imaging of the left atrial lateral wall, and to the peak of the A-wave on the pulsed-wave Doppler of the mitral inflow. There was a significant difference in the baseline atrial conduction time measured by different echocardiographic techniques. Most (88%) patients had normal or only mildly dilated left atrium. At 6 months, 12 patients (38%) had recurrent AF/atrial tachycardia. The duration of history of AF was the only predictor of AF/atrial tachycardia recurrence following the first AF ablation (P=0.024; OR 1.023, CI 1.003–1.044). A combination of normal left atrial volume and history of paroxysmal AF of ≤48 months was associated with the best outcome. Predictive value of the Doppler derived parameters of atrial conduction time may be reduced in the early stages of left atrial remodeling. Future studies may determine which echocardiographic parameter correlates best with the extent of left atrial remodeling and is most predictive of successful AF ablation. PMID:26795694

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

    PubMed

    Uslar, Thomas; Anabalón, Jaime

    2015-08-17

    For most atrial fibrillation patients oral anticoagulation constitutes the standard treatment to prevent stroke. However, they carry a risk of bleeding, which is why alternative treatments have been put into practice, such as percutaneous closure of the left atrial appendage. It is not clear whether this is as effective as the conventional treatment with anticoagulants. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified three systematic reviews including only one pertinent randomized controlled trial. We combined the evidence and generated a summary of findings following the GRADE approach. We concluded that percutaneous left atrial appendage occlusion may decrease stroke and mortality, but the certainty of the evidence is low. The effect on other outcomes is not clear because the certainty of the evidence is very low.

  2. Percutaneous epicardial ablation of incessant atrial tachycardia originating from the left atrial appendage

    PubMed Central

    Ban, Ji-Eun; Park, Tae Young

    2016-01-01

    A 38-year-old woman presented with antiarrhythmic drug-refractory atrial tachycardia (AT). Holter recording demonstrated incessant episodes of AT followed by a long sinus pause. Electrophysiologic study revealed that the earliest endocardial activation was observed at the neck of the left atrial appendage (LAA). After unsuccessful endocardial ablation, epicardial access via a percutaneous subxiphoid approach demonstrated that the earliest epicardial atrial activation was observed on the opposite site to the endocardial LAA neck suggestive of ligament of Marshall (LOM) muscle sleeve as regarding the epicardial sharp potentials under guidance of a circular mapping catheter. Application of radiofrequency (RF) energy at this site terminated the tachycardia. After tachycardia ablation, the sinus pause also resolved. PMID:28066659

  3. Systolic closure of aortic valve in patients with prosthetic mitral valves.

    PubMed Central

    Eldar, M; Motro, M; Rath, S; Schy, N; Neufeld, H N

    1982-01-01

    Systolic closure of the aortic valve was found in 10 of 36 patients who underwent mitral valve replacement. Eight patients had early systolic closure, and two had mid-systolic closure. The left ventricular outflow tract dimension on M-mode and two dimensional echocardiograms, left ventricular posterior wall and septal thickness, left ventricular dimensions in systole and diastole, aortic valve opening, and mitral to aortic valve distance were not significantly different between patients with and without systolic closure of the aortic valve. Two of the 10 patients with systolic aortic valve closure were catheterised and in neither was there a gradient between the left ventricle and the aorta. The two patients with mid-systolic closure, however, were the patients who had the narrowest left ventricular outflow tract which could cause significant distortion of blood flow. Systolic closure of the aortic valve in patients with mitral valve replacement is probably not caused by left ventricular outflow tract obstruction, though abnormalities in laminar flow from the left ventricular outflow tract may be involved. Images PMID:7082513

  4. Atrial fibrillation in obstructive sleep apnea

    PubMed Central

    Goyal, Sandeep K; Sharma, Abhishek

    2013-01-01

    Atrial fibrillation (AF) is a common arrhythmia with rising incidence. Obstructive sleep apnea (OSA) is prevalent among patients with AF. This observation has prompted significant research in understanding the relationship between OSA and AF. Multiple studies support a role of OSA in the initiation and progression of AF. This association has been independent of obesity, body mass index and hypertension. Instability of autonomic tone and wide swings in intrathoracic pressure are seen in OSA. These have been mechanistically linked to initiation of AF in OSA patients by lowering atrial effective refractory period, promoting pulmonary vein discharges and atrial dilation. OSA not only promotes initiation of AF but also makes management of AF difficult. Drug therapy and electrical cardioversion for AF are less successful in presence of OSA. There has been higher rate of early and overall recurrence after catheter ablation of AF in patients with OSA. Treatment of OSA with continuous positive airway pressure has been shown to improve control of AF. However, additional studies are needed to establish a stronger relationship between OSA treatment and success of AF therapies. There should be heightened suspicion of OSA in patients with AF. There is a need for guidelines to screen for OSA as a part of AF management. PMID:23802045

  5. Right atrial thrombi: Percutaneous mechanical thrombectomy

    SciTech Connect

    Beregi, Jean-Paul; Aumegeat, Valerie; Loubeyre, Christophe; Coullet, Jean-Michel; Asseman, Philippe; Debacker-Steckelorom, Caroline; Bauchart, Jean-Jacques; Liu Pengcheng; Thery, Claude

    1997-03-15

    The current therapeutic options for right atrial thrombi-surgical embolectomy and thrombolysis- are associated with high mortality and such patients often have contraindications to these therapeutic options. the purpose of this study was to evaluate the feasibility of endovascular right atrial embolectomy. Two patients with contraindications to thrombolysis and surgery were treated by a femoral approach. A catheter was placed in the right atrium, under fluoroscopic control, and a basket device was used to trap the thrombus. The location and extent of the thrombus was established before the procedure by transesophageal echocardiography (TEE) and the procedure was performed with TEE and fluoroscopy. Thrombi were withdrawn in the basket into the inferior vena cava (IVC) and a filter was inserted by a jugular approach and positioned in the IVC, just above the thrombi. The basket was removed leaving the thrombus below the filter. One patient died immediately after the procedure. In conclusion, endovascular extraction of right atrial thrombi may represent a potential therapeutic alternative, particularly in patients with contraindications to thrombolysis and surgery.

  6. Atrial fibrillation: effects beyond the atrium?

    PubMed

    Wijesurendra, Rohan S; Casadei, Barbara

    2015-03-01

    Atrial fibrillation (AF) is the most common sustained clinical arrhythmia and is associated with significant morbidity, mostly secondary to heart failure and stroke, and an estimated two-fold increase in premature death. Efforts to increase our understanding of AF and its complications have focused on unravelling the mechanisms of electrical and structural remodelling of the atrial myocardium. Yet, it is increasingly recognized that AF is more than an atrial disease, being associated with systemic inflammation, endothelial dysfunction, and adverse effects on the structure and function of the left ventricular myocardium that may be prognostically important. Here, we review the molecular and in vivo evidence that underpins current knowledge regarding the effects of human or experimental AF on the ventricular myocardium. Potential mechanisms are explored including diffuse ventricular fibrosis, focal myocardial scarring, and impaired myocardial perfusion and perfusion reserve. The complex relationship between AF, systemic inflammation, as well as endothelial/microvascular dysfunction and the effects of AF on ventricular calcium handling and oxidative stress are also addressed. Finally, consideration is given to the clinical implications of these observations and concepts, with particular reference to rate vs. rhythm control.

  7. Dronedarone in the management of atrial fibrillation

    PubMed Central

    Saleem, TS Mohamed; Bharani, K; Chetty, C Madhusudhana; Gauthaman, K

    2010-01-01

    Atrial fibrillation is the most common type of tachyarrhythmia caused by multiple re-entrant wave forms within the atria and bombarding the atrioventricular node several times making it beat in a rapid, disorganized fashion termed “fibrillation”. In atrial fibrillation, atria beat more than 300 times per minute. The arrhythmatous condition needs to be controlled, as humans cannot withstand this rapid and chaotic beating of the heart. New investigational drugs like Dronedarone® are being used. Dronedarone is the most recent antiarrhythmic drugs. It was approved by US-FDA on July 2nd 2009 and is available in the USA as Multaq tablets (400 mg). Dronedarone falls under the category of multiple ion channel blocker. It mainly targets the repolarization currents, making them less active and hence prolonging the action potential duration (APD). Dronedarone also exhibits antiadrenergic activity, thus reducing the pace of the pacemaker. Dronedarone has been proven to be a safer and efficacious AAD, evidenced by both animal and human studies. These studies showed that there was prolongation of the APD and absence of QT interval prolongation with long term administration of the drug. Also there was reduced thyroid hormone receptor expression. Dronedarone is significantly safer and effective in maintaining the sinus rhythm and reducing the ventricular proarrhythmias, justifying it for the long term treatment of atrial fibrillation compared to other antiarrhythmic drugs. PMID:27147833

  8. Benchmarking electrophysiological models of human atrial myocytes

    PubMed Central

    Wilhelms, Mathias; Hettmann, Hanne; Maleckar, Mary M.; Koivumäki, Jussi T.; Dössel, Olaf; Seemann, Gunnar

    2013-01-01

    Mathematical modeling of cardiac electrophysiology is an insightful method to investigate the underlying mechanisms responsible for arrhythmias such as atrial fibrillation (AF). In past years, five models of human atrial electrophysiology with different formulations of ionic currents, and consequently diverging properties, have been published. The aim of this work is to give an overview of strengths and weaknesses of these models depending on the purpose and the general requirements of simulations. Therefore, these models were systematically benchmarked with respect to general mathematical properties and their ability to reproduce certain electrophysiological phenomena, such as action potential (AP) alternans. To assess the models' ability to replicate modified properties of human myocytes and tissue in cardiac disease, electrical remodeling in chronic atrial fibrillation (cAF) was chosen as test case. The healthy and remodeled model variants were compared with experimental results in single-cell, 1D and 2D tissue simulations to investigate AP and restitution properties, as well as the initiation of reentrant circuits. PMID:23316167

  9. [Pharmacological rate control therapy for atrial fibrillation].

    PubMed

    Ishikawa, Toshiyuki

    2013-01-01

    Many studies have reported that there is no significant difference in survival rate between rhythm control and rate control strategies in combination of with anticoagulation in patients with atrial fibrillation. Even in patients with atrial fibrillation and with heart failure there is no significant difference in survival rate between both strategies. There is no need of strict rate control. In patients with permanent atrial fibrillation, lemient rate control(resting heart rate of below 110 beats per minute) is as effective as strict rate control (< 70 beats per minute) and easier to achieve. Digitalis, beta-blockers and Ca channel blockers are used for rate control treatments. Digitalis is the only drug that has both decreasing ventricular response by suppressing atrioventricular conduction and inotropic effects. However, digitalis can not suppress heart rates during exercise. Beta-blockers and Ca channel blockers can suppress heart rates not only at rest but also during exercise. Ca channel blockers can not be used for patients with heart failure due to reduction in contractility of heart muscle. It has been reported that cardiac function and survival rate can be improved by beta-blockers in patients with heart failure if starting low dose and increasing gradually.

  10. Animal studies of epicardial atrial ablation.

    PubMed

    Schuessler, Richard B; Lee, Anson M; Melby, Spencer J; Voeller, Rochus K; Gaynor, Sydney L; Sakamoto, Shun-Ichiro; Damiano, Ralph J

    2009-12-01

    The Cox maze procedure is an effective treatment of atrial fibrillation, with a long-term freedom from recurrence greater than 90%. The original procedure was highly invasive and required cardiopulmonary bypass. Modifications of the procedure that eliminate the need for cardiopulmonary bypass have been proposed, including use of alternative energy sources to replace cut-and-sew lesions with lines of ablation made from the epicardium on the beating heart. This has been challenging because atrial wall muscle thickness is extremely variable, and the muscle can be covered with an epicardial layer of fat. Moreover, the circulating intracavitary blood acts as a potential heat sink, making transmural lesions difficult to obtain. In this report, we summarize the use of nine different unidirectional devices (four radiofrequency, two microwave, two lasers, one cryothermic) for creating continuous transmural lines of ablation from the atrial epicardium in a porcine model. We define a unidirectional device as one in which all the energy is applied by a single transducer on a single heart surface. The maximum penetration of any device was 8.3 mm. All devices except one, the AtriCure Isolator pen, failed to penetrate 2 mm in some nontransmural sections. Future development of unidirectional energy sources should be directed at increasing the maximum depth and the consistency of penetration.

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

    PubMed Central

    Smorodinova, Natalia; Bláha, Martin; Melenovský, Vojtěch; Rozsívalová, Karolína; Přidal, Jaromír; Ďurišová, Mária; Pirk, Jan; Kautzner, Josef; Kučera, Tomáš

    2017-01-01

    Background Atrial fibrillation (AF) is the most common arrhythmia and despite obvious clinical importance remains its pathogenesis only partially explained. A relation between inflammation and AF has been suggested by findings of increased inflammatory markers in AF patients. Objective The goal of this study was to characterize morphologically and functionally CD45-positive inflammatory cell populations in atrial myocardium of patients with AF as compared to sinus rhythm (SR). Methods We examined 46 subjects (19 with AF, and 27 in SR) undergoing coronary bypass or valve surgery. Peroperative bioptic samples of the left and the right atrial tissue were examined using immunohistochemistry. Results The number of CD3+ T-lymphocytes and CD68-KP1+ cells were elevated in the left atrial myocardium of patients with AF compared to those in SR. Immune cell infiltration of LA was related to the rhythm, but not to age, body size, LA size, mitral regurgitation grade, type of surgery, systemic markers of inflammation or presence of diabetes or hypertension. Most of CD68-KP1+ cells corresponded to dendritic cell population based on their morphology and immunoreactivity for DC-SIGN. The numbers of mast cells and CD20+ B-lymphocytes did not differ between AF and SR patients. No foci of inflammation were detected in any sample. Conclusions An immunohistochemical analysis of samples from patients undergoing open heart surgery showed moderate and site-specific increase of inflammatory cells in the atrial myocardium of patients with AF compared to those in SR, with prevailing population of monocyte-macrophage lineage. These cells and their cytokine products may play a role in atrial remodeling and AF persistence. PMID:28225836

  12. Neuronally released vasoactive intestinal polypeptide alters atrial electrophysiological properties and may promote atrial fibrillation

    PubMed Central

    Xi, Yutao; Chao, Zhi-Yang James; Yan, Wen; Abbasi, Shahrzad; Yin, Xiaomeng; Mathuria, Nilesh; Patel, Mehul; Fan, Christopher; Sun, Junping; Wu, Geru; Wang, Suwei; Elayda, MacArthur; Gao, Lianjun; Wehrens, Xander H.T.; Lin, Shien-Fong; Cheng, Jie

    2015-01-01

    BACKGROUND Vagal hyperactivity promotes atrial fibrillation (AF), which has been almost exclusively attributed to acetylcholine. Vasoactive intestinal polypeptide (VIP) and acetylcholine are neurotransmitters co-released during vagal stimulation. Exogenous VIP has been shown to promote AF by shortening action potential duration (APD), increasing APD spatial heterogeneity, and causing intra-atrial conduction block. OBJECTIVE The purpose of this study was to investigate the effects of neuronally released VIP on atrial electrophysiologic properties during vagal stimulation. METHODS We used a specific VIP antagonist (H9935) to uncover the effects of endogenous VIP released during vagal stimulation in canine hearts. RESULTS H9935 significantly attenuated (1) the vagally induced shortening of atrial effective refractory period and widening of atrial vulnerability window during stimulation of cervical vagosym-pathetic trunks (VCNS) and (2) vagal effects on APD during stimulation through fat-pad ganglion plexus (VGPS). Atropine completely abolished these vagal effects during VCNS and VGPS. In contrast, VGPS-induced slowing of local conduction velocity was completely abolished by either VIP antagonist or atropine. In pacing-induced AF during VGPS, maximal dominant frequencies and their spatial gradients were reduced significantly by H9935 and, more pronouncedly, by atropine. Furthermore, VIP release in the atria during vagal stimulation was inhibited by atropine, which may account for the concealment of VIP effects with muscarinic blockade. CONCLUSION Neuronally released VIP contributes to vagal effects on atrial electrophysiologic properties and affects the pathophysiology of vagally induced AF. Neuronal release of VIP in the atria is inhibited by muscarinic blockade, a novel mechanism by which VIP effects are concealed by atropine during vagal stimulation. PMID:25748673

  13. Atrial Tachycardias after Atrial Fibrillation Ablation Manifest Different Waveform Characteristics: Implications for Characterizing Tachycardias

    PubMed Central

    Biviano, Angelo B.; Ciaccio, Edward J.; Fleitman, Jessica; Knotts, Robert; Lawrence, John; Haynes, Norrisa; Cyrille, Nicole; Hickey, Kathleen; Iyer, Vivek; Wan, Elaine; Whang, William; Garan, Hasan

    2015-01-01

    INTRODUCTON Atrial fibrillation (AF) ablation patients often manifest atrial tachycardias (AT) with atypical ECG morphologies that preclude accurate localization and mechanism. Diagnostic maneuvers used to define ATs during electrophysiology studies can be limited by tachycardia termination or transformation. Additional methods of characterizing post-AF ablation ATs are required. METHODS AND RESULTS We evaluated the utility of noninvasive ECG signal analytics in post-ablation AF patients for the following features: 1) Localization of ATs (i.e., right versus left atrium), and 2) Identification of common left AT mechanisms (i.e., focal vs. macroreentrant). Atrial waveforms from the surface ECG were used to analyze: 1) Spectral organization, including dominant amplitude (DA) and mean spectral profile (MP), and 2) Temporospatial variability, using temporospatial correlation coefficients. We studied 94 ATs in 71 patients who had undergone prior pulmonary vein isolation for AF and returned for a second ablation: 1) right atrial cavotricuspid-isthmus dependent (CTI) ATs (n=21); 2) left atrial macroreentrant ATs (n=41) and focal ATs (n=32). Right CTI ATs manifested higher DAs and lower MPs than left ATs, indicative of greater stability and less complexity in the frequency spectrum. Left macroreentrant ATs possessed higher temporospatial organization than left focal ATs. CONCLUSIONS Noninvasively recorded atrial waveform signal analyses show that right ATs possess more stable activation properties than left ATs, and left macroreentrant ATs manifest higher temporospatial organization than left focal ATs. Further prospective analyses evaluating the role these novel ECG-derived tools can play to help localize and identify mechanisms of common ATs in AF ablation patients are warranted. PMID:26228873

  14. Efficacy of anticoagulation in resolving left atrial and left atrial appendage thrombi: A transesophageal echocardiographic study

    NASA Technical Reports Server (NTRS)

    Jaber, W. A.; Prior, D. L.; Thamilarasan, M.; Grimm, R. A.; Thomas, J. D.; Klein, A. L.; Asher, C. R.

    2000-01-01

    BACKGROUND: Transesophageal echocardiography (TEE) is the gold standard for evaluation of the left atrium and the left atrial appendage (LAA) for the presence of thrombi. Anticoagulation is conventionally used for patients with atrial fibrillation to prevent embolization of atrial thrombi. The mechanism of benefit and effectiveness of thrombi resolution with anticoagulation is not well defined. METHODS AND RESULTS: We used a TEE database of 9058 consecutive studies performed between January 1996 and November 1998 to identify all patients with thrombi reported in the left atrium and/or LAA. One hundred seventy-four patients with thrombi in the left atrial cavity (LAC) and LAA were identified (1.9% of transesophageal studies performed). The incidence of LAA thrombi was 6.6 times higher than LAC thrombi (151 vs 23, respectively). Almost all LAC thrombi were visualized on transthoracic echocardiography (90.5%). Mitral valve pathology was associated with LAC location of thrombi (P <.0001), whereas atrial fibrillation or flutter was present in most patients with LAA location of thrombi. Anticoagulation of 47 +/- 18 days was associated with thrombus resolution in 80.1% of the patients on follow-up TEE. Further anticoagulation resulted in limited additional benefit. CONCLUSIONS: LAC thrombi are rare and are usually associated with mitral valve pathology. Transthoracic echocardiography is effective in identifying these thrombi. LAA thrombi occur predominantly in patients with atrial fibrillation or flutter. Short-term anticoagulation achieves a high rate of resolution of LAA and LAC thrombi but does not obviate the need for follow-up TEE.

  15. Effects of Adrenergic Receptor Activation and Blockade on the Systolic Preejection Period, Heart Rate, and Arterial Pressure in Man

    PubMed Central

    Harris, Willard S.; Schoenfeld, Clyde D.; Weissler, Arnold M.

    1967-01-01

    We have investigated the possibility that alterations in the duration of the systolic preejection period can be used to estimate adrenergic influences on the human left ventricle. The preejection period was determined from high speed, simultaneous recordings of the phonocardiogram, carotid pulse tracing, and electrocardiogram. The preejection period was shortened by isoproterenol, epinephrine, and moderate doses of norepinephrine—all of which activate beta adrenergic receptors—and by cedilanid-D. It was unaltered by changes in heart rate induced by atropine and right atrial electrical pacing. Beta adrenergic receptor blockade by propranolol abolished the shortening effects of the three catecholamines but did not inhibit that due to cedilanid-D. Vasoconstriction, both alpha adrenergic (epinephrine and norepinephrine after propranolol) and nonadrenergic (angiotensin), prolonged the preejection period. Most of the shortening of the preejection period by beta adrenergic receptor activating agents and cedilanid-D and all of the prolongation accompanying pharmacologic vasoconstriction occurred after the onset of the first heart sound, thereby excluding changes in electrical-mechanical delay as a major factor in the observed preejection period responses. Shortening of the preejection period by beta adrenergic activity induced with isoproterenol was dose-related. Increasing doses of propranolol produced parallel shifts to the right in the isoproterenol dose-response curve. In 37 normal resting subjects intravenous propranolol (10 mg) prolonged the preejection period an average of 10 (SE ± 1) msec. In six patients with psychogenic sinus tachycardia and a patient with a pheochromocytoma the presence of excessive beta adrenergic influences on the left ventricle was demonstrated by the finding of an initially short preejection period which responded with an abnormally great prolongation to beta adrenergic receptor blockade. Images PMID:4294053

  16. Pharmacokinetics of intravenously and orally administered sotalol hydrochloride in horses and effects on surface electrocardiogram and left ventricular systolic function.

    PubMed

    Broux, B; De Clercq, D; Decloedt, A; De Baere, S; Devreese, M; Van Der Vekens, N; Ven, S; Croubels, S; van Loon, G

    2016-02-01

    Arrhythmias are common in horses. Some, such as frequent atrial or ventricular premature beats, may require long-term anti-arrhythmic therapy. In humans and small animals, sotalol hydrochloride (STL) is often used for chronic oral anti-arrhythmic therapy. STL prolongs repolarization and the effective refractory period in all cardiac tissues. No information on STL pharmacokinetics or pharmacodynamics in horses is available and the aim of this study was to evaluate the pharmacokinetics of intravenously (IV) and orally (PO) administered STL and the effects on surface electrocardiogram and left ventricular systolic function. Six healthy horses were given 1 mg STL/kg bodyweight either IV or PO. Blood samples to determine plasma STL concentrations were taken before and at several time points after STL administration. Electrocardiography and echocardiography were performed at different time points before and after IV STL administration. Mean peak plasma concentrations after IV and PO administration of STL were 1624 ng/mL and 317 ng/mL, respectively. The oral bioavailability was intermediate (48%) with maximal absorption after 0.94 h, a moderate distribution and a mean elimination half-life of 15.24 h. After IV administration, there was a significant increase in QT interval, but no significant changes in other electrocardiographic and echocardiographic parameters. Transient transpiration was observed after IV administration, but no adverse effects were noted after a single oral dose of 1 mg/kg STL in any of the horses. It was concluded that STL has an intermediate oral bioavailability in the horse and might be useful in the treatment of equine arrhythmias.

  17. Secondary flow morphologies due to model stent-induced perturbations in a 180° curved tube during systolic deceleration

    NASA Astrophysics Data System (ADS)

    Bulusu, Kartik V.; Plesniak, Michael W.

    2013-03-01

    Morphological changes in secondary flow structures due to a stent model were investigated under physiological inflow conditions. The stent model was inserted upstream of a 180° curved tube artery model. A carotid artery flow rate with its characteristic systolic and diastolic phases was supplied by a pump to drive a blood-analog working fluid. Phase-averaged, two-component, two-dimensional (2C-2D) particle image velocimeter measurements revealed the changing morphologies of these secondary flow structures. Continuous wavelet transforms provided an enhanced means to detect coherent secondary flow structures in this bio-inspired experimental study. A two-dimensional Ricker wavelet was used, and the optimal wavelet scale was determined using Shannon entropy as a measure of randomness in the wavelet-transformed vorticity fields. Planar secondary flow vortical structures at the 90° location in the curved tube were observed to exhibit distinct spatio-temporal characteristics different than the baseline flow without the stent. Flow patterns observed at the systolic peak comprised of early Lyne-type, along with a deformed Dean-type pair of ordered, coherent, high-circulation and counter-rotating vortical structures. Systolic deceleration was marked by the breakdown of large-scale coherent vortices into multiple, disordered, low-circulation, coherent vortical structures, indicating new transitional secondary flow morphologies. These multi-scale secondary flow morphologies arise due to the combination of imbalances in centrifugal and pressure forces, and stent-induced flow perturbations. The detailed flow physics associated with the formation of Dean and Lyne vortices are described in previous publications that have been cited in the manuscript. The secondary flow structures reported here are driven by similar fundamental mechanisms, but additionally contain more complicated effects, such as asymmetry and multiple strengths, that cannot be predicted from simple theories.

  18. Clinical usefulness of the second peak of radial systolic blood pressure for estimation of aortic systolic blood pressure.

    PubMed

    Kohara, K; Tabara, Y; Tomita, H; Nagai, T; Igase, M; Miki, T

    2009-08-01

    Central aortic blood pressure (BP), obtained from radial arterial waveform using the transfer function method (TFM), has been shown to have prognostic value independently of brachial BP. In this study, the relationship between peripheral systolic BP (SBP) and aortic SBP was evaluated. We further investigated whether TFM-derived aortic SBP can be estimated by information obtained from the radial waveform. The radial waveform was analysed to obtain the first peak of radial SBP (SBP1), second peak of radial SBP (SBP2), radial augmentation index (AI) (radial (SBP2-DBP)/(SBP1-DBP) x 100 and aortic SBP and AI using TFM in 233 subjects in the supine position. Measurements were repeated after changing position to the prone position. The constructed equation was validated in 149 community residents with different backgrounds. Radial SBP2 was closer to TFM-derived aortic SBP compared with brachial SBP. TFM-derived aortic SBP was approximated by the equation: aortic SBP=18.9-radial SBP2-0.03 x HR-0.214 x radial AI (r2=0.992). The equation was also applicable to predicting aortic SBP in the prone position as well as in different populations (mean difference between predicted aortic SBP and TFM-derived aortic SBP: -0.01+/-1.34 and 1.05+/-1.47 mm Hg, respectively). Radial arterial waveform analysis can be used for estimation of TFM-derived aortic SBP.

  19. Endothelial function in postmenopausal women with nighttime systolic hypertension

    PubMed Central

    Routledge, Faye S.; Hinderliter, Alan L.; McFetridge-Durdle, Judith; Blumenthal, James A.; Paine, Nicola J.; Sherwood, Andrew

    2014-01-01

    Objective Hypertension becomes more prevalent in women during their postmenopausal years. Nighttime systolic blood pressure (SBP) is especially predictive of adverse cardiac events and the relationship between rising nighttime SBP and cardiovascular risk increases more rapidly in women compared to men. The reasons for the prognostic significance of nighttime SBP are not completely known, but may involve vascular endothelial dysfunction. The purpose of this study was to examine the relationship of nighttime SBP and endothelial function, assessed by brachial artery flow-mediated dilation (FMD) and to determine whether postmenopausal women with nighttime hypertension (SBP≥120 mm Hg) evidenced greater endothelial dysfunction compared to women with normal nighttime SBP. Methods One-hundred postmenopausal women (mean age: 65.8 ± 7.5 years, body mass index: 28.3 ± 4.7 kg/m2, hypertension: 47%, coronary artery disease: 51%, mean clinic BP 137 ± 17/67 ± 11 mm Hg, 34 with nighttime hypertension) underwent 24-hour ambulatory BP monitoring, actigraphy, and brachial artery FMD assessments. Results Multivariate regression models showed that higher nighttime SBP and larger baseline artery diameter were inversely related to FMD. Nighttime SBP and baseline artery diameter accounted for 23% of the variance in FMD. After adjusting for baseline artery diameter, women with nighttime hypertension had lower FMD than women with normal nighttime SBP (2.95%±0.65 vs 5.52%±0.46, p = .002). Conclusions In postmenopausal women, nighttime hypertension was associated with reduced endothelial function. Research examining the therapeutic benefits of treating nighttime hypertension on endothelial function and future cardiovascular risk in postmenopausal women is warranted. PMID:25563797

  20. Use of Inotropic Agents in Treatment of Systolic Heart Failure.

    PubMed

    Tariq, Sohaib; Aronow, Wilbert S

    2015-12-04

    The most common use of inotropes is among hospitalized patients with acute decompensated heart failure, with reduced left ventricular ejection fraction and with signs of end-organ dysfunction in the setting of a low cardiac output. Inotropes can be used in patients with severe systolic heart failure awaiting heart transplant to maintain hemodynamic stability or as a bridge to decision. In cases where patients are unable to be weaned off inotropes, these agents can be used until a definite or escalated supportive therapy is planned, which can include coronary revascularization or mechanical circulatory support (intra-aortic balloon pump, extracorporeal membrane oxygenation, impella, left ventricular assist device, etc.). Use of inotropic drugs is associated with risks and adverse events. This review will discuss the use of the inotropes digoxin, dopamine, dobutamine, norepinephrine, milrinone, levosimendan, and omecamtiv mecarbil. Long-term inotropic therapy should be offered in selected patients. A detailed conversation with the patient and family shall be held, including a discussion on the risks and benefits of use of inotropes. Chronic heart failure patients awaiting heart transplants are candidates for intravenous inotropic support until the donor heart becomes available. This helps to maintain hemodynamic stability and keep the fluid status and pulmonary pressures optimized prior to the surgery. On the other hand, in patients with severe heart failure who are not candidates for advanced heart failure therapies, such as transplant and mechanical circulatory support, inotropic agents can be used for palliative therapy. Inotropes can help reduce frequency of hospitalizations and improve symptoms in these patients.

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

    PubMed Central

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

    2016-01-01

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

  2. Effect of whiskey on atrial vulnerability and "holiday heart".

    PubMed

    Engel, T R; Luck, J C

    1983-03-01

    Vulnerability to atrial fibrillation and flutter was examined in 11 alcohol abusers who did not have cardiomyopathy or manifest heart failure. Atrial extrastimulation was done with rapid pacing (drive cycle length 500 ms) to facilitate induction of atrial vulnerability, seen in four alcohol abusers. The remaining seven were retested 30 minutes after drinking 60 to 120 ml of 86 proof whiskey (ethanol blood levels were 49 to 101 mg/100 ml but pulmonary capillary wedge pressure remained normal in all) and atrial fibrillation or flutter was induced in three of the drinkers. Three nondrinkers, symptomatic with sinus bradycardia but not in heart failure, were found not to be vulnerable to atrial fibrillation or flutter, but flutter was induced in two of the three after drinking whiskey. Whiskey did not alter atrial functional refractory periods (mean +/- standard error of the mean 297 +/- 14 to 290 +/- 12 ms) or widen the dispersion among three disparate right atrial sites (57 +/- 13 to 47 +/- 12 ms). Thus, whiskey enhanced vulnerability to atrial fibrillation and flutter in patients without heart failure or cardiomyopathy, substantiating the "holiday heart" syndrome.

  3. Atrial Arrhythmias and Their Implications for Space Flight - Introduction

    NASA Technical Reports Server (NTRS)

    Polk, J. D.; Barr, Y. R.; Bauer, P.; Hamilton, D. R.; Kerstman, E.; Tarver, B.

    2010-01-01

    This panel will discuss the implications of atrial arrhythmias in astronauts from a variety of perspectives; including historical data, current practices, and future challenges for exploration class missions. The panelists will present case histories, outline the evolution of current NASA medical standards for atrial arrhythmias, discuss the use of predictive tools, and consider potential challenges for current and future missions.

  4. Atrial rate and rhythm abnormalities in a patient with hyperkalemia.

    PubMed

    Rosman, Jonathan; Thiagarajah, Prashan; Schweitzer, Paul; Rachko, Maurice; Hanon, Sam

    2009-05-15

    A 67 year old man presented with a serum potassium of 7.7 mEq/L and slow atrial flutter with variable A-V block and peaked T waves. Initial treatment for hyperkalemia was followed by an increase in the atrial flutter rate to 300 beats per minute. After hemodialysis the rhythm converted to sinus.

  5. Atrial myxoma: a rare cause of ischemic stroke.

    PubMed

    Negi, R C; Chauhan, Vivek; Sharma, Brij; Bhardwaj, Rajeev; Thakur, Surinder

    2013-04-01

    Arial myxoma can present as stroke and should be considered as a differential diagnosis of stroke in young individuals. We present here a 42 years female who presented with sudden loss of conciousness. After extensive work up for young stroke, left atrial myxoma was detected and tumor was removed surgically and histopathological report was consistent with the atrial myxoma.

  6. Dynamics of Focal Fibrillation Waves during Persistent Atrial Fibrillation.

    PubMed

    Lanters, Eva A H; Allessie, Maurits A; DE Groot, Natasja M S

    2016-04-01

    The incidence and appearance of focal fibrillation waves on the right and left atrial epicardial surface were visualized during 10 seconds of persistent atrial fibrillation in a 71-year-old woman with valvular heart disease. The frequent, nonrepetitive, widespread, and capricious distribution of focal waves suggests that transmural conduction of fibrillation waves is most likely the mechanism underlying focal fibrillation waves.

  7. Regional left atrial function differentiation in patients with constrictive pericarditis and restrictive cardiomyopathy: a study using speckle tracking echocardiography.

    PubMed

    Liu, Shuang; Ma, Chunyan; Ren, Weidong; Zhang, Jing; Li, Nan; Yang, Jun; Zhang, Yan; Qiao, Wei

    2015-12-01

    Left atrial (LA) function plays an important role in the maintenance of cardiac output. However, whether assessment of regional LA myocardial dysfunction is useful for differentiating between CP and restrictive cardiomyopathy (RCM) remains unclear. Thirty-five patients with CP, 30 patients with RCM, and 30 healthy volunteers (controls) were enrolled in this study. The LA maximum volume (Vmax), LA minimal volume (Vmin), and LA volume before atrial contraction (Vpre-a) were measured using the biplane modified Simpson's rule. All patients underwent two-dimensional speckle tracking echocardiography (STE). The peak systolic strain rate (SrS), early diastolic strain rate (SrE), and late diastolic strain rate (SrA) of the LA septum, LA lateral wall and superior walls were measured. The LA diastolic and systolic function was found to be reduced in patients with CP and RCM. The SrE in the LA superior wall and lateral wall were significantly decreased in patients with CP and RCM compared with controls (P < 0.001). The SrE of the LA septum in patients with CP was preserved compared to normal controls. Althouth the LA septal SrE in patients with CP was significantly reduced (P < 0.001). For the diagnosis of RCM, a cutoff value 1.40 for SrE of the LA septum showed a sensitivity of 94.7 % and a specificity of 89.7 %. The SrE in the LA superior wall and lateral wall were decreased while the LA septal SrE was preserved in patients with CP, indicating that the rigid pericardium might restrict myocardial motion and deformation in the lateral wall. The measurement of STE to determine the LA septal SrE can be helpful for differentiating between CP and RCM.

  8. The utility of transoesophageal echocardiography for estimating right ventricular systolic pressure.

    PubMed

    Cowie, B; Kluger, R; Rex, S; Missant, C

    2015-03-01

    With the reduction in use of the pulmonary artery catheter, alternative methods of pulmonary pressure estimation are required. The use of echocardiographically-derived right ventricular systolic pressure has recently been questioned, but this technique has not been validated in anaesthetised surgical patients with transoesophageal echocardiography. One hundred measurements of right ventricular systolic pressure with transoesophageal echocardiography were compared with the pulmonary artery systolic pressure obtained simultaneously from a pulmonary artery catheter in patients undergoing cardiac surgery. Simultaneous right ventricular systolic pressure and pulmonary artery systolic pressure measurements were possible in all patients, and these measurements were strongly correlated (r = 0.98, p < 0.001), with minimal bias and narrow limits of agreement (approximately -5 to +5 mmHg), across a broad range of pulmonary pressures. Measurement of right ventricular systolic pressure using tranoesophageal echocardiography is readily achievable and closely correlates with pulmonary artery systolic pressure, with minimal bias, in cardiac surgical patients undergoing general anaesthesia and positive pressure mechanical ventilation of the lungs.

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

    PubMed

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

    2015-11-01

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

  10. Imaging Techniques in Percutaneous Cardiac Structural Interventions: Atrial Septal Defect Closure and Left Atrial Appendage Occlusion.

    PubMed

    Rodríguez Fernández, Antonio; Bethencourt González, Armando

    2016-08-01

    Because of advances in cardiac structural interventional procedures, imaging techniques are playing an increasingly important role. Imaging studies show sufficient anatomic detail of the heart structure to achieve an excellent outcome in interventional procedures. Up to 98% of atrial septal defects at the ostium secundum can be closed successfully with a percutaneous procedure. Candidates for this type of procedure can be identified through a systematic assessment of atrial septum anatomy, locating and measuring the size and shape of all defects, their rims, and the degree and direction of shunting. Three dimensional echocardiography has significantly improved anatomic assessments and the end result itself. In the future, when combined with other imaging techniques such as cardiac computed tomography and fluoroscopy, 3-dimensional echocardiography will be particularly useful for procedure guidance. Percutaneous closure of the left atrial appendage offers an alternative for treating patients with atrial fibrillation and contraindication for oral anticoagulants. In the future, the clinical focus may well turn to stroke prevention in selected patients. Percutaneous closure is effective and safe; device implantation is successful in 94% to 99% of procedures. However, the procedure requires an experienced cardiac structural interventional team. At present, 3-dimensional echocardiography is the most appropriate imaging technique to assess anatomy suitability, select device type and size, guide the procedure alongside fluoroscopy, and to follow-up the patient afterwards.

  11. Atrial fibrillation and gastroesophageal reflux disease: From the cardiologist perspective.

    PubMed

    Floria, Mariana; Drug, Vasile Liviu

    2015-03-14

    We have read with interest the paper by Roman C. and colleagues discussing the relationship between gastroesophageal reflux disease and atrial fibrillation. The review is presenting the available evidence for the common pathogenic mechanisms. However, from a cardiologist perspective, some available data were not highlighted in the review, cardiovascular involvement in gastroesophageal reflux is less assessed. Hypertension, obesity or diabetes mellitus are substrate for left atrial remodeling that initiate and sustained atrial fibrillation development. One of the pathophysiologic mechanisms in atrial fibrillation is the presence of a trigger. Gastroesophageal reflux could be only a trigger for this arrhythmia. We believe that atrial fibrillation should be considered as possible extraesophageal syndrome in the gastroesophageal reflux classification.

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

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  13. Blood pressure control versus atrial fibrillation management in stroke prevention.

    PubMed

    Savoia, Carmine; Sada, Lidia; Volpe, Massimo

    2015-06-01

    Hypertension is one of the major risk factors for atrial fibrillation which in turn is the most prevalent concomitant condition in hypertensive patients. While both these pathological conditions are independent risk factors for stroke, the association of hypertension and atrial fibrillation increases the incidence of disabling strokes. Moreover, documented or silent atrial fibrillation doubles the rate of cardiovascular death. Lowering blood pressure is strongly recommended, particularly for primary stroke prevention. However, a relatively small percentage of hypertensive patients still achieve the recommended blood pressure goals. The management of atrial fibrillation with respect to stroke prevention is changing. New oral anticoagulants represent a major advancement in long-term anticoagulation therapy in non valvular atrial fibrillation. They have several benefits over warfarin, including improved adherence to the anticoagulation therapy. This is an important issue since non-adherence to stroke prevention medications is a risk factor for first and recurrent strokes.

  14. Disturbed Left Atrial Function is Associated with Paroxysmal Atrial Fibrillation in Hypertension

    PubMed Central

    Tenekecioglu, Erhan; Agca, Fahriye Vatansever; Ozluk, Ozlem Arican; Karaagac, Kemal; Demir, Serafettin; Peker, Tezcan; Kuzeytemiz, Mustafa; Senturk, Muhammed; Yılmaz, Mustafa

    2014-01-01

    Background Hypertension is the most prevalent and modifiable risk factor for atrial fibrillation. The pressure overload in the left atrium induces pathophysiological changes leading to alterations in contractile function and electrical properties. Objective In this study our aim was to assess left atrial function in hypertensive patients to determine the association between left atrial function with paroxysmal atrial fibrillation (PAF). Method We studied 57 hypertensive patients (age: 53±4 years; left ventricular ejection fraction: 76±6.7%), including 30 consecutive patients with PAF and 30 age-matched control subjects. Left atrial (LA) volumes were measured using the modified Simpson's biplane method. Three types of LA volume were determined: maximal LA(LAVmax), preatrial contraction LA(LAVpreA) and minimal LA volume(LAVmin). LA emptying functions were calculated. LA total emptying volume = LAVmax−LAVmin and the LA total EF = (LAVmax-LAVmin )/LAVmax, LA passive emptying volume = LAVmax− LAVpreA and the LA passive EF = (LAVmax-LAVpreA)/LAVmax, LA active emptying volume = LAVpreA−LAVmin and LA active EF = (LAVpreA-LAVmin )/LAVpreA. Results The hypertensive period is longer in hypertensive group with PAF. LAVmax significantly increased in hypertensive group with PAF when compared to hypertensive group without PAF (p=0.010). LAAEF was significantly decreased in hypertensive group with PAF as compared to hypertensive group without PAF (p=0.020). A' was decreased in the hypertensive group with PAF when compared to those without PAF (p = 0.044). Conclusion Increased LA volume and impaired LA active emptying function was associated with PAF in untreated hypertensive patients. Longer hypertensive period is associated with PAF. PMID:24676227

  15. Disrupted Calcium Release as a Mechanism for Atrial Alternans Associated with Human Atrial Fibrillation

    PubMed Central

    Chang, Kelly C.; Bayer, Jason D.; Trayanova, Natalia A.

    2014-01-01

    Atrial fibrillation (AF) is the most common cardiac arrhythmia, but our knowledge of the arrhythmogenic substrate is incomplete. Alternans, the beat-to-beat alternation in the shape of cardiac electrical signals, typically occurs at fast heart rates and leads to arrhythmia. However, atrial alternans have been observed at slower pacing rates in AF patients than in controls, suggesting that increased vulnerability to arrhythmia in AF patients may be due to the proarrythmic influence of alternans at these slower rates. As such, alternans may present a useful therapeutic target for the treatment and prevention of AF, but the mechanism underlying alternans occurrence in AF patients at heart rates near rest is unknown. The goal of this study was to determine how cellular changes that occur in human AF affect the appearance of alternans at heart rates near rest. To achieve this, we developed a computational model of human atrial tissue incorporating electrophysiological remodeling associated with chronic AF (cAF) and performed parameter sensitivity analysis of ionic model parameters to determine which cellular changes led to alternans. Of the 20 parameters tested, only decreasing the ryanodine receptor (RyR) inactivation rate constant (kiCa) produced action potential duration (APD) alternans seen clinically at slower pacing rates. Using single-cell clamps of voltage, fluxes, and state variables, we determined that alternans onset was Ca2+-driven rather than voltage-driven and occurred as a result of decreased RyR inactivation which led to increased steepness of the sarcoplasmic reticulum (SR) Ca2+ release slope. Iterated map analysis revealed that because SR Ca2+ uptake efficiency was much higher in control atrial cells than in cAF cells, drastic reductions in kiCa were required to produce alternans at comparable pacing rates in control atrial cells. These findings suggest that RyR kinetics may play a critical role in altered Ca2+ homeostasis which drives proarrhythmic

  16. Prevalence of left atrial abnormalities in atrial fibrillation versus normal sinus patients

    PubMed Central

    Ketai, Loren H; Teague, Shawn D; Rissing, Stacy M

    2016-01-01

    Background Atrial fibrillation (AF) may be the cause or sequela of left atrial abnormalities and variants. Purpose To determine the prevalence of left atrial (LA) abnormalities in AF patients compared to normal sinus rhythm (NSR) patients. Material and Methods We retrospectively reviewed 281 cardiac CT examinations from 2010 to 2012, excluding patients with prior pulmonary vein ablation, known coronary artery disease, prior coronary stent placement, or coronary artery bypass grafts. The first group consisted of 159 AF patients undergoing cardiac CT prior to pulmonary vein ablation and the second group consisted of 122 NSR patients evaluated with coronary CT angiography. Demographic data were collected. LA abnormalities were analyzed. Left atrial diameter was measured on an axial view. Results A total of 281 patients were included. The male gender has significantly higher prevalence of AF than female gender, P value <0.001. Patients with AF were significantly older (mean age, 57.4 years; standard deviation [SD], 11.8 years) than NSR patients (mean age, 53.4 years; SD, 13.6 years), P value, 0.01. The left atrial diameter was greater in the AF patients (mean diameter, 4.3 cm; SD, 0.82 cm) versus the NSR patients (3.4 cm; SD, 0.58 cm), P value, <0.0001. LA diverticulum was the most prevalent variant, occurring in 28.4% of the entire patient population followed by LA pouch, occurring in 24%. There was no significant between group differences in the prevalence of these or the remainder of the LA variants. Conclusion AF patients differed significantly from NSR patients in LA size, gender, and mean age. There was no statistical significance between the two groups with regard to the LA morphologic abnormalities other than size. PMID:27358747

  17. Minimally invasive surgery for atrial fibrillation

    PubMed Central

    Suwalski, Piotr

    2013-01-01

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

  18. Pulmonary venous flow determinants of left atrial pressure under different loading conditions in a chronic animal model with mitral regurgitation

    NASA Technical Reports Server (NTRS)

    Yang, Hua; Jones, Michael; Shiota, Takahiro; Qin, Jian Xin; Kim, Yong Jin; Popovic, Zoran B.; Pu, Min; Greenberg, Neil L.; Cardon, Lisa A.; Eto, Yoko; Sitges, Marta; Zetts, Arthur D.; Thomas, James D.

    2002-01-01

    BACKGROUND: The aim of our study was to quantitatively compare the changes and correlations between pulmonary venous flow variables and mean left atrial pressure (mLAP) under different loading conditions in animals with chronic mitral regurgitation (MR) and without MR. METHODS: A total of 85 hemodynamic conditions were studied in 22 sheep, 12 without MR as control (NO-MR group) and 10 with MR (MR group). We obtained pulmonary venous flow systolic velocity (Sv) and diastolic velocity (Dv), Sv and Dv time integrals, their ratios (Sv/Dv and Sv/Dv time integral), mLAP, left ventricular end-diastolic pressure, and MR stroke volume. We also measured left atrial a, x, v, and y pressures and calculated the difference between v and y pressures. RESULTS: Average MR stroke volume was 10.6 +/- 4.3 mL/beat. There were good correlations between Sv (r = -0.64 and r = -0.59, P <.01), Sv/Dv (r = -0.62 and r = -0.74, P <.01), and mLAP in the MR and NO-MR groups, respectively. Correlations were also observed between Dv time integral (r = 0.61 and r = 0.57, P <.01) and left ventricular end-diastolic pressure in the MR and NO-MR groups. In velocity variables, Sv (r = -0.79, P <.001) was the best predictor of mLAP in both groups. The sensitivity and specificity of Sv = 0 in predicting mLAP 15 mm Hg or greater were 86% and 85%, respectively. CONCLUSION: Pulmonary venous flow variables correlated well with mLAP under altered loading conditions in the MR and NO-MR groups. They may be applied clinically as substitutes for invasively acquired indexes of mLAP to assess left atrial and left ventricular functional status.

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

    PubMed

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

    2016-04-12

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

  20. The Epidemiology of Atrial Fibrillation and Stroke.

    PubMed

    Pistoia, Francesca; Sacco, Simona; Tiseo, Cindy; Degan, Diana; Ornello, Raffaele; Carolei, Antonio

    2016-05-01

    The burden of stroke is increasing due to aging population and unhealthy lifestyle habits. The considerable rise in atrial fibrillation (AF) is due to greater diffusion of risk factors and screening programs. The link between AF and ischemic stroke is strong. The subtype most commonly associated with AF is cardioembolic stroke, which is particularly severe and shows the highest rates of mortality and permanent disability. A trend toward a higher prevalence of cardioembolic stroke in high-income countries is probably due to the greater diffusion of AF and the control of atherosclerotic of risk factors.

  1. Science Linking Pulmonary Veins and Atrial Fibrillation

    PubMed Central

    Mahida, Saagar; Sacher, Frederic; Derval, Nicolas; Berte, Benjamin; Yamashita, Seigo; Hooks, Darren; Denis, Arnaud; Amraoui, Sana; Hocini, Meleze; Haissaguerre, Michel; Jais, Pierre

    2015-01-01

    Over the past few decades, significant progress has been made in understanding the mechanistic basis of atrial fibrillation (AF). One of the most important discoveries in this context has been that pulmonary veins (PV) play a prominent role in the pathogenesis of AF. PV isolation has since become the most widely used technique for treatment of paroxysmal AF. Multiple studies have demonstrated that the electrophysiological and anatomical characteristics of PVs create a proarrhythmogenic substrate. The following review discusses the mechanistic links between PVs and AF. PMID:26835098

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

    NASA Technical Reports Server (NTRS)

    Tarver, William J.

    2010-01-01

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

  3. The polyuria of paroxysmal atrial tachycardia

    NASA Technical Reports Server (NTRS)

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

    1974-01-01

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

  4. Stroke prevention in patients with atrial fibrillation: The diagnosis and management of hypertension by specialists

    PubMed Central

    Healey, Jeff S; Wharton, Sean; Al-Kaabi, Saif; Pai, Menaka; Ravandi, Amir; Nair, Girish; Morillo, Carlos A; Connolly, Stuart J

    2006-01-01

    BACKGROUND Hypertension is common in patients with atrial fibrillation (AF) and is an important cause of stroke. OBJECTIVES To determine how effectively hypertension is managed among specialist-treated outpatients with AF. METHODS Investigators reviewed the charts of patients with a diagnosis of AF cared for by medical specialists to determine the change in blood pressure, patterns of antihypertensive drug use and the role of the specialist in the management of hypertension. RESULTS Of 209 patients with AF, 118 had a history of hypertension or an office blood pressure greater than 140/90 mmHg. Blood pressure was measured at 73% of all visits. Hypertension was identified as an important problem in 57% of patients and antihypertensive therapy was either initiated or suggested in 77%. One year after the initial specialist visit, systolic blood pressure was significantly lower (140±20 mmHg at one year versus 148±23 mmHg initially; P=0.015); however, there was no change in diastolic blood pressure (80±12 mmHg at one year versus 81±16 mmHg initially; P=0.602) and only 50% of patients had a blood pressure less than 140/90 mmHg. In contrast, the percentage of patients receiving warfarin increased from 46% to 78% (P=0.0001). CONCLUSIONS In patients treated by specialists for AF, systolic blood pressure is significantly reduced during follow-up; however, 50% of patients continue to have suboptimal blood pressure control. In many patients, hypertension is not identified as an important comorbid illness and antihypertensive therapy is neither recommended nor initiated by the specialist. Greater specialist involvement in the identification and treatment of hypertension in patients with AF could lead to an important, additional reduction in stroke. PMID:16685312

  5. Comparison of National Football League linemen versus nonlinemen of left ventricular mass and left atrial size.

    PubMed

    Croft, Lori B; Belanger, Adam; Miller, Marc A; Roberts, Arthur; Goldman, Martin E

    2008-08-01

    Retired National Football League (NFL) linemen have higher cardiovascular mortality compared with nonlinemen. We examined echocardiographic characteristics of retired NFL linemen compared with nonlinemen to determine if position-dependent cardiac remodeling resulted in increased left ventricular (LV) mass and left atrial (LA) size. We performed echocardiography in 487 retired NFL football players. Demographic, medical, and professional career information was collected. Interventricular septal and posterior wall thickness, LV end diastolic diameter, and LA area were measured. Body mass index (BMI) and LV mass were calculated. Retired linemen had significantly higher LV mass (234.8 +/- 65.8 g) than nonlinemen (199.8 +/- 55.4 g, p <0.0001). LA area was higher in linemen versus nonlinemen (22.5 vs 20.1 cm(2), p <0.0001). Independent predictors of increased LV mass were BMI (p <0.003), linemen position (p <0.024), and systolic blood pressure (p <0.005). In former players with BMI <35 kg/m(2) there was a difference between linemen and nonlinemen in LV mass (219.9 +/- 44.3 vs 182.6 +/- 44.3 g, p = 0.004) and LV mass/height (114.3 +/- 23.5 vs 98.8 +/- 25.2 g/m, p = 0.005). In former players with BMI >35 kg/m(2), there was no difference. There was no difference in LA area between linemen and nonlinemen in both BMI groups. In conclusion, LV mass and LA area size were highest in retired linemen. Player BMI, position, and systolic blood pressure were significant predictors of LV mass. In retired linemen compared with retired nonlinemen, the persistence of these cardiac adaptations may contribute to the higher cardiovascular mortality seen in retired linemen.

  6. The influence of white-coat hypertension on left atrial phasic function.

    PubMed

    Tadic, Marijana; Cuspidi, Cesare; Pencic, Biljana; Rihor, Branislav; Radojkovic, Jana; Kocijanic, Vesna; Celic, Vera

    2017-04-01

    We aimed to investigate the association between white-coat hypertension (WCH) and left atrial (LA) phasic function assessed by the volumetric and speckle tracking method. This cross-sectional study included 52 normotensive individuals, 49 subjects with WCH and 56 untreated hypertensive patients who underwent a 24-h ambulatory BP monitoring and complete two-dimensional echocardiographic examination (2DE). WCH was diagnosed if clinic blood pressure (BP) was elevated and 24-h BP was normal. We obtained that maximum, minimum LA and pre-A LAV volumes and volume indexes gradually and significantly increased from the normotensive subjects, throughout the white-coat hypertensive individuals to the hypertensive patients. Passive LA emptying fraction (EF), representing the LA conduit function, gradually reduced from normotensive to hypertensive subjects. Active LA EF and the parameter of the LA booster pump function increased in the same direction. Similar results were obtained by 2DE strain analysis. The LA stiffness index gradually increased from normotensive controls, throughout white-coat hypertensive subjects to hypertensive patients. Clinic systolic BP was associated with LA passive EF (β= -0.283, p = 0.001), LA active EF (β = 0.342, p < 0.001), LA total longitudinal strain (β= -0.356, p < 0.001), LA positive longitudinal strain (β= -0.264, p = 0.009) and LA stiffness index (β = 0.398, p < 0.001) without regard to age, BMI, left ventricular structure and diastolic function in the whole study population. In the conclusion, WCH significantly impacts LA phasic function and stiffness. Clinic systolic BP was associated with functional and mechanical LA remodeling in the whole study population.

  7. Real-time SPARSE-SENSE cine MR imaging in atrial fibrillation: a feasibility study.

    PubMed

    Goebel, Juliane; Nensa, Felix; Schemuth, Haemi P; Maderwald, Stefan; Quick, Harald H; Schlosser, Thomas; Nassenstein, Kai

    2016-01-01

    Background Cardiac magnetic resonance imaging (MRI) relies on correct ECG-gating, which is hindered in arrhythmia. Purpose To examine whether a prototype free-breathing real-time cine sequence using SPARSE-SENSE (SPARSE) improves left ventricular quantification in atrial fibrillation. Material and Methods On a 1.5T MR system left ventricular short-axis stacks were acquired of the SPARSE sequence and of a "reference" steady-state free precession (SSFP) sequence with arrhythmia rejection in 20 patients with atrial fibrillation. Two radiologists independently rated arrhythmia-caused artifact severity in both sequences using a 4-point scale. Coefficients of variation of myocardial signal intensity for both sequences were acquired. Volumetry was performed twice by one reader and once by another reader. Correlation between artifact severity and employed sequence was analyzed by modified Fisher's exact test. Coefficients of variation and volumetric data were compared by paired t-test and intraclass correlation. Results Median arrhythmia-caused artifact severity was 2 in both readers for SSFP and 0 (reader 1)/1 (reader 2) for SPARSE, being significantly lower in SPARSE ( P < 0.001). Mean coefficient of variance was significantly smaller in SPARSE (0.11 ± 0.04) compared to SSFP (0.22 ± 0.13, P = 0.003), which was interpreted as a hint for fewer artifacts in SPARSE. Only a small difference of 9 ± 15 mL was seen for end-systolic volume ( P = 0.019) between sequences, otherwise no significant difference was detected (end-diastolic volume, P = 0.200; stroke volume, P = 0.554; ejection fraction, P = 0.136; myocardial mass, P = 0.353). Intraclass correlation between sequences was good to excellent (range, 0.80-0.97). Conclusion Real-time MRI with SPARSE data sampling is promising in atrial fibrillation because it reduces arrhythmia-caused artifacts.

  8. ECG Segmentation and P-Wave Feature Extraction: Application to Patients Prone to Atrial Fibrillation

    DTIC Science & Technology

    2007-11-02

    detection of patients prone to atrial fibrillation (AF), one of the most frequent arrhythmias. It focuses first on the segmentation of the...Keywords : atrial fibrillation , ECG segmentation, P-wave, hidden Markov model, wavelets, ECG database I. INTRODUCTION Atrial fibrillation (AF) is a very... atrial thrombosis, with the subsequent risk of a stroke. The aim of this study is to try to automatically detect patients prone to atrial fibrillation (AF

  9. On the design of fault-tolerant two-dimensional systolic arrays for yield enhancement

    SciTech Connect

    Kim, J.H.; Reddy, S.M.

    1989-04-01

    The continuing growth of interest in systolic arrays poses the problem of ensuring an acceptable yield. In this paper, the authors propose a unified approach to the design of fault-tolerant systolic arrays incorporating design for testability, a testing scheme, a reconfiguration algorithm, time complexity analysis of the proposed reconfiguration algorithm, and yield analysis. A main feature of the proposed designs is that multiple PE's in a 2-D array can be tested simultaneously, thus reducing the testing time significantly. Another feature is that with introduction of delay registers, the proposed reconfiguration algorithm reconfigures a faulty 2-D systolic array into a fault-free array without reducing throughput. The overall aim of this paper is to provide a design for a 2-D systolic array that produces high yield in VLSI/WSI implementations.

  10. Sources of variation in assessing left atrial functions by 2D speckle-tracking echocardiography.

    PubMed

    Rimbaş, Roxana Cristina; Mihăilă, Sorina; Vinereanu, Dragoş

    2016-03-01

    Left atrial (LA) strain and strain rate, determined by speckle-tracking echocardiography (STE), are reproducible indices to assess LA function. Different normal ranges for LA phasic functions have been reported. We investigated the role of the reference point (P- and R-wave), gain, and region of interest (ROI), as the major sources of variation when assessing LA function. 52 subjects were evaluated for LA conventional and STE analysis. 45 of them (46 ± 14 years, 26 men) were feasible for concomitant LA deformation, and LA phasic volumes and ejection fractions (LAEF) evaluation. First, we compared the P- and R-wave methods, for the evaluation of the LA functions. We used diastolic mitral profile to clearly delineate the time intervals for each LA function. For the P-wave method, active function was assessed from negative global strain as a difference between the strain at pre-atrial contraction and strain just before mitral valve closure (GSA-), and late diastolic strain rate (GSRL); passive function from positive strain at MVO (GSA+), and from early negative diastolic strain rate (GSRE); reservoir function from the sum of GSA- and GSA+ (TGSA), and positive strain rate at the beginning of LV systole (GSR+). For the R-wave method we used the same SR parameters. The active function was evaluated by late positive global strain (GSAC), the reservoir by positive peak before the opening of the mitral valve (TGSA), and conduit function by the difference between TGSA and GSAC (GSA+). Then, by using P-wave method, we measured all previously described parameters for different gains-minimum (G0), medium (G12), and maximum (G24), and for different ROIs-minimum (ROI0), step 1 (ROI1), and 2 (ROI2). Feasibility of the LA strain measurements was 87 %. Active LA function was similar in the absolute value (GSAC and GSA-), whereas passive and reservoir functions were significantly higher (GSA+, TGSA) with the R-wave method. Active LAEF correlated with GSA- measured by the P-wave (r

  11. Pulmonary Hypertension Secondary to Left Ventricular Systolic Dysfunction: Contemporary Diagnosis and Management

    PubMed Central

    Shah, Ravi V.; Semigran, Marc J.

    2011-01-01

    Pulmonary hypertension secondary to left ventricular systolic dysfunction is often a poor prognostic marker in chronic heart failure. In this article, we review evidence supporting modern strategies addressing pulmonary hypertension in patients with left ventricular systolic dysfunction, including right-sided heart catheterization with vasoreactivity testing and subsequent parenteral, oral, and inhaled therapy. We delineate a diagnostic approach to secondary pulmonary hypertension and outline evidence-based therapeutic strategies for management in acute and chronic heart failure. PMID:19032918

  12. Radial Pulse Character Relationship to Systolic Blood Pressure and Trauma Outcomes

    DTIC Science & Technology

    2005-12-01

    RADIAL PULSE CHARACTER RELATIONSHIPS TO SYSTOLIC BLOOD PRESSURE AND TRAUMA OUTCOMES John McManus, MD, MCR, Andrey L. Yershov, MD, PhD, David Ludwig...pable pulse characteristics in the radial artery would es- timate systolic blood pressure (SBP) and predict outcome in trauma patients. Methods. Data...setting is problematic. The ability to obtain a blood pressure (BP) measurement in an aus- tere environment is often limited by time constraints

  13. Angiocardiographic appearances of atrioventricular defects with particular reference to distinction of ostium primum atrial septal defect from common atrioventricular orifice.

    PubMed Central

    Macartney, F J; Rees, P G; Daly, K; Piccoli, G P; Taylor, J F; De Leval, M R; Stark, J; Anderson, R H

    1979-01-01

    Preoperative distinction between common atrioventricular orifice and ostium primum atrial septal defect may be difficult. To improve diagnostic accuracy, the right and left ventricle angiocardiograms were reviewed 'blind' in 92 patients with atrioventricular defects. The true diagnosis was known from necropsy or surgery in 60. Angiocardiograms had been obtained in various projections with or without craniocaudal tilt. Those features thought to distinguish between common orifice and ostium primum were coded, together with the ventricular systolic pressures. Computerised disciminant function analysis identified the following distinguishing features: (1) right ventricular systolic pressure; (2) immediate right ventricular outflow tract opacification from the left ventricle; (3) identification of the anterior attachment of the mitral component; (4) recognition of a single straddling atrioventricular orifice; (5) passage of contrast medium above or below the anterior or posterior bridging leaflets. Feature (3) indicates that in contrast to classic teaching the direct septal attachment of the mitral component does not contribute to the 'gooseneck' in complete atrioventricular defects. The significance of (4) and (5) is that they may be identified from right as well as left ventriculography, and are more likely to be identified in oblique than standard projections. Computerisation produced a correct diagnosis in 92 per cent of known cases, and determined precise probabilities of diagnosis in the remainder. Images PMID:534581

  14. Imaging atrial arrhythmic intracellular calcium in intact heart

    PubMed Central

    Xie, Wenjun; Santulli, Gaetano; Guo, Xiaoxiao; Gao, Melanie; Chen, Bi-Xing; Marks, Andrew R.

    2014-01-01

    Abnormalities in intracellular Ca2+ signaling have been proposed to play an essential role in the pathophysiology of atrial arrhythmias. However, a direct observation of intracellular Ca2+ in atrial myocytes during atrial arrhythmias is lacking. Here, we have developed an ex vivo model of simultaneous Ca2+ imaging and electrocardiographic recording in cardiac atria. Using this system we were able to record atrial arrhythmic intracellular Ca2+ activities. Our results indicate that atrial arrhythmias can be tightly linked to intracellular Ca2+ waves and Ca2+ alternans. Moreover, we applied this strategy to analyze Ca2+ signals in the hearts of WT and knock-in mice harboring a ‘leaky’ type 2 ryanodine receptor (RyR2-R2474S). We showed that sarcoplasmic reticulum (SR) Ca2+ leak increases the susceptibility to Ca2+ alternans and Ca2+ waves increasing the incidence of atrial arrhythmias. Reduction of SR Ca2+ leak via RyR2 by acute treatment with S107 reduced both Ca2+ alternans and Ca2+ waves, and prevented atrial arrhythmias. PMID:24041536

  15. Cyclical stretch induces structural changes in atrial myocytes.

    PubMed

    De Jong, Anne Margreet; Maass, Alexander H; Oberdorf-Maass, Silke U; De Boer, Rudolf A; Van Gilst, Wiek H; Van Gelder, Isabelle C

    2013-06-01

    Atrial fibrillation (AF) often occurs in the presence of an underlying disease. These underlying diseases cause atrial remodelling, which make the atria more susceptible to AF. Stretch is an important mediator in the remodelling process. The aim of this study was to develop an atrial cell culture model mimicking remodelling due to atrial pressure overload. Neonatal rat atrial cardiomyocytes (NRAM) were cultured and subjected to cyclical stretch on elastic membranes. Stretching with 1 Hz and 15% elongation for 30 min. resulted in increased expression of immediate early genes and phosphorylation of Erk and p38. A 24-hr stretch period resulted in hypertrophy-related changes including increased cell diameter, reinduction of the foetal gene program and cell death. No evidence of apoptosis was observed. Expression of atrial natriuretic peptide, brain natriuretic peptide and growth differentiation factor-15 was increased, and calcineurin signalling was activated. Expression of several potassium channels was decreased, suggesting electrical remodelling. Atrial stretch-induced change in skeletal α-actin expression was inhibited by pravastatin, but not by eplerenone or losartan. Stretch of NRAM results in elevation of stress markers, changes related to hypertrophy and dedifferentiation, electrical remodelling and cell death. This model can contribute to investigating the mechanisms involved in the remodelling process caused by stretch and to the testing of pharmaceutical agents.

  16. Idiopathic atrial fibrillation in a champion Standardbred racehorse.

    PubMed

    Stewart, G A; Fulton, L J; McKellar, C D

    1990-05-01

    Atrial fibrillation is described in a champion pacer which earlier had been named Australian Harness Horse of the Year as a 3-year-old in 1986-87. Prior to conversion atrial fibrillation had been present for at least 6 weeks, during which the horse had not raced. Successful treatment was achieved with two 10g doses of quinidine sulphate per oesophageal tube, after slow digitalisation with intravenous digoxin over 4d. Four hours after commencement of quinidine therapy the arrhythmia had regressed to atrial flutter and converted to sinus rhythm 10 min later. Considering his age, standard of racing and high reputation the horse's overall performance as a 5-year-old after conversion from atrial fibrillation appeared comparable to his previous performance as a 4-year-old before the disorder occurred. In one of the wins since his return to sinus rhythm, the horse recorded his fastest winning speed and created a new track record at the major Melbourne racetrack. The absence of abnormalities of atrial and atrio-ventricular conduction after the cessation of the arrhythmia, together with the horse's return to successful racing, indicate that this was case of atrial fibrillation occurring as a functional disorder without persistent atrial pathology.

  17. Imaging atrial arrhythmic intracellular calcium in intact heart.

    PubMed

    Xie, Wenjun; Santulli, Gaetano; Guo, Xiaoxiao; Gao, Melanie; Chen, Bi-Xing; Marks, Andrew R

    2013-11-01

    Abnormalities in intracellular Ca(2+) signaling have been proposed to play an essential role in the pathophysiology of atrial arrhythmias. However, a direct observation of intracellular Ca(2+) in atrial myocytes during atrial arrhythmias is lacking. Here, we have developed an ex vivo model of simultaneous Ca(2+) imaging and electrocardiographic recording in cardiac atria. Using this system we were able to record atrial arrhythmic intracellular Ca(2+) activities. Our results indicate that atrial arrhythmias can be tightly linked to intracellular Ca(2+) waves and Ca(2+) alternans. Moreover, we applied this strategy to analyze Ca(2+) signals in the hearts of WT and knock-in mice harboring a 'leaky' type 2 ryanodine receptor (RyR2-R2474S). We showed that sarcoplasmic reticulum (SR) Ca(2+) leak increases the susceptibility to Ca(2+) alternans and Ca(2+) waves increasing the incidence of atrial arrhythmias. Reduction of SR Ca(2+) leak via RyR2 by acute treatment with S107 reduced both Ca(2+) alternans and Ca(2+) waves, and prevented atrial arrhythmias.

  18. Recent topics on the surgical treatment for atrial fibrillation.

    PubMed

    Misaki, Takuro; Fukahara, Kazuaki

    2004-10-01

    After the introduction of endocardial radiofrequency catheter, only two arrhythmias, atrial fibrillation and ischemic ventricular tachycardia require surgical procedures. In this review, we describe recent advancements and problems of surgical treatment for atrial fibrillation. On the basis of multiple-circuit re-entry theory, Cox developed the maze operation with the aim of interrupting the re-entry circuit. Although this procedure has become the gold standard technique for the surgical treatment of atrial fibrillation with approximately 90% success rate, several modifications have been made over time. To obtain a more physiological atrial transport function, radial approach technique or bilateral appendage-preserved maze procedures were developed and to simplify surgical procedures, maze operation with cryo-ablation or radiofrequency-ablation were created. Other topics are concerned with surgical target or approach to atrial fibrillation. Ectopic focus theories from pulmonary veins have been widely recognized recently and the surgical isolation of pulmonary veins orifices is performed with various energy sources. In addition to standard cut-and-sew surgical technique, cryoablation, unipolar or bipolar radiofrequency ablation, or microwave ablation were induced with endocardial or epicardial approach for the achievement of less invasive cardiac surgery. As atrial fibrillation leads to frequent mortality, cardiac surgeons have to treat atrial fibrillation with other cardiac disease more frequently to obtain better quality of operative results.

  19. Reference values of tricuspid annular peak systolic velocity in healthy pediatric patients, calculation of z score, and comparison to tricuspid annular plane systolic excursion.

    PubMed

    Koestenberger, Martin; Nagel, Bert; Ravekes, William; Avian, Alexander; Heinzl, Bernd; Cvirn, Gerhard; Fritsch, Peter; Fandl, Andrea; Rehak, Thomas; Gamillscheg, Andreas

    2012-01-01

    The tricuspid annular peak systolic velocity (TAPSV) is an echocardiographic measurement assessing right ventricular systolic function in children and adults. We determined the growth-related changes of the TAPSV to establish the references values for the entire pediatric age group. A prospective study was conducted of a group of 860 healthy pediatric patients (age 1 day to 18 years; body surface area [BSA] 0.14 to 2.30 m(2)). We determined the effects of age, gender, and BSA on the TAPSV values. Stepwise linear multiple regression analysis was used to estimate the TAPSV from the age, BSA, and gender. A correlation of normal TAPSV with normal tricuspid annular plane systolic excursion values was performed. The TAPSV ranged from a mean of 7.2 cm/s (z score ± 2: 4.8 to 9.5 cm/s) in the newborn to 14.3 cm/s (z score ± 2: 10.6 to 18.6 cm/s) in the 18-year-old adolescent. The TAPSV values showed a positive correlation with age and BSA, with a nonlinear course. No significant difference was found in the TAPSV values according to gender. A significant correlation was found between the TAPSV and tricuspid annular plane systolic excursion values in our pediatric population. In conclusion, the z scores of the TAPSV values were calculated, and percentile charts were established to serve as reference data for patients with congenital heart disease.

  20. Relation of porphyria to atrial fibrillation.

    PubMed

    Dhoble, Abhijeet; Patel, Mehul B; Abdelmoneim, Sahar S; Puttarajappa, Chethan; Abela, George S; Bhatt, Deepak L; Thakur, Ranjan K

    2009-08-01

    Porphyrias are a group of inherited disorders affecting enzymes in the heme biosynthesis pathway, leading to overproduction and/or accumulation of porphyrin or its precursors. Porphyrias have been associated with autonomic dysfunction, which in turn can develop atrial fibrillation (AF). The purpose of this study was to characterize the prevalence of AF and atrial flutter (AFl) in patients with porphyrias. A single-center retrospective cohort study was designed using data from chart reviews of patients who were admitted to the hospital from January 2000 to June 2008. Fifty-six distinct cases were found with a discharge diagnosis of porphyria including all its subtypes. From the same database, age- and gender-matched controls were identified using computer-generated random numbers. We selected 1 age- and gender-matched control for each case. Electrocardiograms and echocardiograms were reviewed by 2 independent reviewers. Only patients with available 12-lead electrocardiograms that showed AF/AFl were labeled with that diagnosis. All patients with a diagnosis of porphyria were included in the study irrespective of their age. Seven of 56 patients with porphyria met inclusion criteria, yielding a prevalence of AF/AFl of 12.5%. This association was significant (p = 0.028, relative risk 7.45, 95% confidence interval 1.01 to 66.14) compared with the age- and gender-matched control group (2%). In conclusion, our observations suggest that porphyria may be significantly associated with AF/AFl.

  1. [Right atrial thrombosis with acute abdominal onset].

    PubMed

    Petcu, D P; Petcu, C; Roşu, M

    2009-01-01

    Intracardiac masses are detected more frequently due to the availability of echocardiography. Right atrial thrombosis is rare comparatively with that of the left atrium. The clinical presentation of the patient with right atrial thrombosis is linked with a misleading association between cardiovascular signs and digestive signs (acute abdominal pain, vomiting and marmorated skin of flanks). Initial clinical suspicions of acute pancreatitis, entero-mesenteric infarction and complicated gastro-duodenal ulcer were invalidated by imagistic investigations -- echocardiography and CT. The massive thrombus located in the right atrium, prolapsing during diastole through the tricuspid valve, was associated with the increase in plasmatic D-dimers and new ECG modifications type right bundle block (hemodynamic straining of the right ventricle). The evolution was favorable, after heparin-therapy by infusing pump, with relief of cardiovascular and digestive symptoms after the first 6 hours; after 36 h from the beginning of the treatment the thrombus was lysed. Sudden death likelihood through complete obstruction of the tricuspid ostium was prevented due to the early diagnosis offered by imagistic methods.

  2. Realizations and performances of least-squares estimation and Kalman filtering by systolic arrays

    SciTech Connect

    Chen, M.J.

    1987-01-01

    Fast least-squares (LS) estimation and Kalman-filtering algorithms utilizing systolic-array implementation are studied. Based on a generalized systolic QR algorithm, a modified LS method is proposed and shown to have superior computational and inter-cell connection complexities, and is more practical for systolic-array implementation. After whitening processing, the Kalman filter can be formulated as a SRIF data-processing problem followed by a simple LS operation. This approach simplifies the computational structure, and is more reliable when the system has singular or near singular coefficient matrix. To improve the throughput rate of the systolic Kalman filter, a topology for stripe QR processing is also proposed. By skewing the order of input matrices, a fully pipelined systolic Kalman-filtering operation can be achieved. With the number of processing units of the O(n/sup 2/), the system throughput rate becomes of the O(n). The numerical properties of the systolic LS estimation and the Kalman filtering algorithms under finite word-length effect are studied via analysis and computer simulations, and are compared with that of conventional approaches. Fault tolerance of the LS estimation algorithm is also discussed. It is shown that by using a simple bypass register, reasonable estimation performance is still possible for a transient defective processing unit.

  3. Reproducibility of the systolic time intervals: effect of the temporal range of measurements.

    PubMed

    Kupari, M

    1983-06-01

    The aim of this study was to evaluate the reproducibility of conventionally measured systolic time intervals. To that end, three to eight serial measurements were performed on four different groups of healthy subjects (total number, 49) within dissimilar time periods: 1) within 3 h; 2) within 24 h; 3) within 1 to 2 weeks; and 4) within 14 to 18 months. Judged as the mean coefficients of variation, the variability of the systolic time intervals tended to be smallest in the 3 h measurements and largest in the 24 h measurements. The pooled variances of the serial measurements made within 24 h were in general significantly larger than the respective variances in the measurements made within 3 h. This was due to statistically significant diurnal decreases in left ventricular ejection time and total electromechanic systole in the 24 h study. Otherwise the reproducibility of the method was high. For instance, the mean coefficients of variation for ejection time and total electromechanic systole corrected for heart rate were only 1% and 1.2%, respectively, in serial measurements made at identical diurnal time points within 14 to 18 months. The pooled variances of the measurements made within the shortest and longest temporal ranges were not statistically different. It is concluded that measurement of the systolic time intervals is very applicable to intervention and follow-up studies provided the normal circadian rhythmicity of the phases of systole is adequately taken into account in the design of the study.

  4. Color-coded Doppler imaging of systolic flow patterns in hypertrophic cardiomyopathy.

    PubMed

    Tencate, F J; Mayala, A P; Vletter, W B; Roelandt, J

    1985-01-01

    We studied 11 patients with hypertrophic cardiomyopathy by color Doppler echocardiography (Group I: 6 patients with outflow obstruction, and Group II: 5 patients without outflow obstruction) to assess systolic structure and function as observed by cross-sectional echocardiography in relation to the flow dynamics. The structure and function included systolic anterior motion of mitral valve (SAM), midsystolic aortic valve closure (AoC), systolic cavity obliteration and the presence and timing of mitral incompetence. Their occurrence and timing was related to presence of aortic systolic flow and presence of turbulence. While all patients in Group I had SAM and turbulence, none of the patients in Group II had SAM nor turbulence. Early mitral incompetence appearing before SAM and turbulence, occurred in all patients of Group I and in none of Group II. Midsystolic aortic valve closure was only present in Group I and blood flow was unilaterally directed so that only 60% of aortic cross-sectional area showed blood flow. We conclude that mitral incompetence in hypertrophic cardiomyopathy in early systole is common when outflow gradient is present and is independent of mitral incompetence of mid- and late systole. During SAM, turbulence in the subaortic area and mid and late mitral incompetence occurred simultaneously. The midsystolic aortic valve closure was related to the unilaterally directed blood flow through the aortic cross-sectional area.

  5. Mitral Annular Systolic Velocities Predict Left Ventricular Wall Motion Abnormality During Dobutamine Stress Echocardiography

    PubMed Central

    Sharif, Dawod; Sharif-Rasslan, Amal; Shahla, Camilia

    2011-01-01

    Background Longitudinal systolic left ventricular contraction is complementary to the radial performance and can be assessed using tissue Doppler imaging (TDI). This study was performed to evaluate the contribution of mitral annular systolic velocities using TDI after dobutamine stress echocardiography (DSE). Methods and Results Fifty subjects with suspected coronary artery disease and chest pain were examined, using DSE as usual, as well as TDI imaging of the mitral annulus at the septal, lateral, inferior, anterior, posterior regions and the proximal anteroseptal region from the apical views, before and immediately after DSE. In 24 subjects the study was normal, while wall motion abnormality was seen in 26, 9 of them only after DSE. Mitral annular systolic velocity at the 6 locations increased significantly after DSE both in normal subjects and in those with wall motion abnormality (WMA). After DSE mitral annular septal systolic velocity in normals, 19.2 ± 3.8 cm/sec, was higher than in those with WMA, 14.6 ± 2.5 cm/sec, P < 0.0003. Post-DSE mitral systolic velocity was senstive and accurate in predicting WMA. Conclusions Systolic mitral TDI velocities increase after DSE, however to a lesser extent in those with wall motion abnormality, and can differentiate them from normal subjects.

  6. Increased systolic load causes adverse remodeling of fetal aortic and mitral valves

    PubMed Central

    Louey, Samantha; Espinoza, Herbert; Chattergoon, Natasha; You, Fanglei; Thornburg, Kent L.; Giraud, George

    2015-01-01

    While abnormal hemodynamic forces alter fetal myocardial growth, little is known about whether such insults affect fetal cardiac valve development. We hypothesized that chronically elevated systolic load would detrimentally alter fetal valve growth. Chronically instrumented fetal sheep received either a continuous infusion of adult sheep plasma to increase fetal blood pressure, or a lactated Ringer's infusion as a volume control beginning on day 126 ± 4 of gestation. After 8 days, mean arterial pressure was higher in the plasma infusion group (63.0 mmHg vs. 41.8 mmHg, P < 0.05). Mitral annular septal-lateral diameter (11.9 mm vs. 9.1 mm, P < 0.05), anterior leaflet length (7.7 mm vs. 6.4 mm, P < 0.05), and posterior leaflet length (P2; 4.0 mm vs. 3.0 mm, P < 0.05) were greater in the elevated load group. mRNA levels of Notch-1, TGF-β2, Wnt-2b, BMP-1, and versican were suppressed in aortic and mitral valve leaflets; elastin and α1 type I collagen mRNA levels were suppressed in the aortic valves only. We conclude that sustained elevated arterial pressure load on the fetal heart valve leads to anatomic remodeling and, surprisingly, suppression of signaling and extracellular matrix genes that are important to valve development. These novel findings have important implications on the developmental origins of valve disease and may have long-term consequences on valve function and durability. PMID:26354842

  7. [Cardioversion of atrial fibrillation with low energy internal electric shock].

    PubMed

    Ricard, P; Socas, A G; Taramasco, V; Guenoun, M; Lévy, S

    1997-12-01

    The efficacy and safety of low internal cardioversion for the reduction of atrial fibrillation was assessed prospectively in 104 consecutive patients. Sixty-two patients had chronic atrial fibrillation (Group I). 16 patients had paroxysmal atrial fibrillation (Group II) and 26 patients had induced atrial fibrillation (Group III). The average duration of the current episode of atrial fibrillation was 9 +/- 19 months in Group I, 4 +/- 2 days in Group II and 18 +/- 7 minutes in Group III. Two intracardiac defibrillation catheters were used, one (the cathode) in the right atrium and the other in the coronary sinus or left branch of the pulmonary artery (anode). These catheters were connected to an external defibrillator delivering biphasic 3/3 ms shocks with a voltage which could be programmed from 10 to 400 volts. The shocks were synchronised on the R wave. Sinus rhythm was restored in 44 of the 62 patients in Group I (70%), 12 of the 16 patients in Group II (75%) and 20 of the 26 patients in Group III (77%). The average voltages and energies restoring sinus rhythm were 300 +/- 68 volts and 3.5 +/- 1.5 joules respectively in Group I, 245 +/- 72 volts and 2.0 +/- 2.9 joules in Group II, and 270 +/- 67 volts and 2.6 +/- 1.2 joules in Group III. These results show that the energy required to restore sinus rhythm is significantly greater in patients with chronic atrial fibrillation than in patients with paroxysmal or induced atrial fibrillation. There were no ventricular proarrhythmic effects in the 686 shocks synchronised on the R wave. This study shows that internal cardioversion of atrial fibrillation is feasible with low energies under simple sedation. These results support the concept of an implantable atrial defibrillator.

  8. Atrial Arrhythmias in Astronauts - Summary of a NASA Summit

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

    Background and Problem Definition: To evaluate NASA s current standards and practices related to atrial arrhythmias in astronauts, Space Medicine s Advanced Projects Section at the Johnson Space Center was tasked with organizing a summit to discuss the approach to atrial arrhythmias in the astronaut cohort. Since 1959, 11 cases of atrial fibrillation, atrial flutter, or supraventricular tachycardia have been recorded among active corps crewmembers. Most of the cases were paroxysmal, although a few were sustained. While most of the affected crewmembers were asymptomatic, those slated for long-duration space flight underwent radiofrequency ablation treatment to prevent further episodes of the arrhythmia. The summit was convened to solicit expert opinion on screening, diagnosis, and treatment options, to identify gaps in knowledge, and to propose relevant research initiatives. Summit Meeting Objectives: The Atrial Arrhythmia Summit brought together a panel of six cardiologists, including nationally and internationally renowned leaders in cardiac electrophysiology, exercise physiology, and space flight cardiovascular physiology. The primary objectives of the summit discussions were to evaluate cases of atrial arrhythmia in the astronaut population, to understand the factors that may predispose an individual to this condition, to understand NASA s current capabilities for screening, diagnosis, and treatment, to discuss the risks associated with treatment of crewmembers assigned to long-duration missions or extravehicular activities, and to discuss recommendations for prevention or management of future cases. Summary of Recommendations: The summit panel s recommendations were grouped into seven categories: Epidemiology, Screening, Standards and Selection, Treatment of Atrial Fibrillation Manifesting Preflight, Atrial Fibrillation during Flight, Prevention of Atrial Fibrillation, and Future Research

  9. Abnormal heart rate variability and atrial fibrillation after aortic surgery

    PubMed Central

    Compostella, Leonida; Russo, Nicola; D’Onofrio, Augusto; Setzu, Tiziana; Compostella, Caterina; Bottio, Tomaso; Gerosa, Gino; Bellotto, Fabio

    2015-01-01

    Introduction Complete denervation of transplanted heart exerts protective effect against postoperative atrial fibrillation; various degrees of autonomic denervation appear also after transection of ascending aorta during surgery for aortic aneurysm. Objective This study aimed to evaluate if the level of cardiac denervation obtained by resection of ascending aorta could exert any effect on postoperative atrial fibrillation incidence. Methods We retrospectively analysed the clinical records of 67 patients submitted to graft replacement of ascending aorta (group A) and 132 with aortic valve replacement (group B); all episodes of postoperative atrial fibrillation occurred during the 1-month follow-up have been reported. Heart Rate Variability parameters were obtained from a 24-h Holter recording; clinical, echocardiographic and treatment data were also evaluated. Results Overall, 45% of patients (group A 43%, group B 46%) presented at least one episode of postoperative atrial fibrillation. Older age (but not gender, abnormal glucose tolerance, ejection fraction, left atrial diameter) was correlated with incidence of postoperative atrial fibrillation. Only among a subgroup of patients with aortic transection and signs of greater autonomic derangement (heart rate variability parameters below the median and mean heart rate over the 75th percentile), possibly indicating more profound autonomic denervation, a lower incidence of postoperative atrial fibrillation was observed (22% vs. 54%). Conclusion Transection of ascending aorta for repair of an aortic aneurysm did not confer any significant protective effect from postoperative atrial fibrillation in comparison to patients with intact ascending aorta. It could be speculated that a limited and heterogeneous cardiac denervation was produced by the intervention, creating an eletrophysiological substrate for the high incidence of postoperative atrial fibrillation observed. PMID:25859868

  10. Actions of Ya-hom, a herbal drug combination, on isolated rat aortic ring and atrial contractions.

    PubMed

    Suvitayavat, W; Tunlert, S; Thirawarapan, S S; Kitpati, C; Bunyapraphatsara, N

    2005-08-01

    The effect of the Thai popular medicine Ya-hom on cardiovascular function was studied in isolated rat aortic ring and atrium by comparison with norepinephrine (NE). Water extraction of Ya-hom at concentrations of 0.83, 1.67, 8.33 and 16.67 mg/ml stimulated aortic ring contraction dose-dependently. The maximum contraction, at 16.67 mg/ml, was about 14% that of NE. This stimulatory effect of Ya-hom was inhibited partially by phentolamine, which indicated that the effect of Ya-hom was partially dependent on the alpha receptor, similar to NE. Administration of Ya-hom with NR decreased the force of aortic ring contraction as compared to the effect of NE alone, indicating that Ya-hom may have a partial alpha-agonist activity. Ya-hom at concentrations of 1.67, 8.33 and 16.67 mg/ml showed a dose-dependent, positive inotropic and negative chronotropic effects. Ya-hom increased the force of isolated atrial contraction with a slow onset and prolonged action. In contrast to norephinephrine, which acted on beta1 receptor, causing positive inotropic and chronotropic effects, propranolol did not alter the effect of Ya-hom on the atrial contraction. This shows that the action of Ya-hom on atrial contraction does not involve beta receptor.

  11. Pulmonary edema following transcatheter closure of atrial septal defect

    PubMed Central

    Chigurupati, Keerthi; Reshmi, Liza Jose; Gadhinglajkar, Shrinivas; Venkateshwaran, S.; Sreedhar, Rupa

    2015-01-01

    We describe an incident of development of acute pulmonary edema after the device closure of a secundum atrial septal defect in a 52-year-old lady, which was treated with inotropes, diuretics and artificial ventilation. Possibility of acute left ventricular dysfunction should be considered after the defect closure in the middle-aged patients as the left ventricular compliance may be reduced due to increased elastic stiffness and diastolic dysfunction. Baseline left atrial pressure may be > 10 mmHg in these patients. Associated risk factors for the left ventricular dysfunction are a large Qp:Qs ratio, systemic hypertension, severe pulmonary hypertension and paroxysmal atrial fibrillation. PMID:26139760

  12. Biventricular repair of right atrial isomerism with complex congenital anomalies.

    PubMed

    Kirali, Kaan; Sasmazel, Ahmet; Mataraci, Ilker; Erdem, Hasan; Guzelmeric, Fusun

    2010-01-01

    Biventricular repair is usually difficult to achieve in patients who have right atrial isomerism, which is typically associated with other complex cardiac anomalies. The procedure can be used in patients who have balanced ventricular structures. Herein, we report a successful surgical reconstruction, including biventricular repair, in a 4-year-old boy. The child's right atrial isomerism was associated with double-outlet right ventricle, a large atrial septal defect, a subaortic ventricular septal defect, valvular and infundibular pulmonary stenosis, left persistent superior vena cava, and hemiazygos continuation of an interrupted inferior vena cava. Balanced ventricles enabled biventricular repair, which we consider to be preferable to the Fontan procedure in such circumstances.

  13. Surviving Right Atrial Rupture From Blunt Thoracic Trauma After Pericardiectomy.

    PubMed

    Lajevardi, Sepehr Seyed; Galougahi, Keyvan Karimi; Nova, George; Marshman, David

    2016-02-01

    Right atrial rupture secondary to blunt trauma is exceedingly rare. We present a case report of blunt chest trauma and right atrial rupture in a patient with a background of pericardiectomy that were successfully managed surgically. Right atrial rupture must be considered as a differential diagnosis in patients with blunt chest trauma. In patients with previous pericardiectomy, this injury may manifest with massive hemothorax, and insertion of a chest drain should be performed with extreme caution. In our experience, urgent exploratory thoracotomy and repair of the defect are the mainstays of acute management.

  14. Atrial natriuretic peptide affects cardiac remodeling, function, heart failure, and survival in a mouse model of dilated cardiomyopathy.

    PubMed

    Wang, Dong; Gladysheva, Inna P; Fan, Tai-Hwang M; Sullivan, Ryan; Houng, Aiilyan K; Reed, Guy L

    2014-03-01

    Dilated cardiomyopathy is a frequent cause of heart failure and death. Atrial natriuretic peptide (ANP) is a biomarker of dilated cardiomyopathy, but there is controversy whether ANP modulates the development of heart failure. Therefore, we examined whether ANP affects heart failure, cardiac remodeling, function, and survival in a well-characterized, transgenic model of dilated cardiomyopathy. Mice with dilated cardiomyopathy with normal ANP levels survived longer than mice with partial ANP (P<0.01) or full ANP deficiency (P<0.001). In dilated cardiomyopathy mice, ANP protected against the development of heart failure as indicated by reduced lung water, alveolar congestion, pleural effusions, etc. ANP improved systolic function and reduced cardiomegaly. Pathological cardiac remodeling was diminished in mice with normal ANP as indicated by decreased ventricular interstitial and perivascular fibrosis. Mice with dilated cardiomyopathy and normal ANP levels had better systolic function (P<0.001) than mice with dilated cardiomyopathy and ANP deficiency. Dilated cardiomyopathy was associated with diminished cardiac transcripts for NP receptors A and B in mice with normal ANP and ANP deficiency, but transcripts for NP receptor C and C-type natriuretic peptide were selectively altered in mice with dilated cardiomyopathy and ANP deficiency. Taken together, these data indicate that ANP has potent effects in experimental dilated cardiomyopathy that reduce the development of heart failure, prevent pathological remodeling, preserve systolic function, and reduce mortality. Despite the apparent overlap in physiological function between the NPs, these data suggest that the role of ANP in dilated cardiomyopathy and heart failure is not compensated physiologically by other NPs.

  15. Usefulness of Left Atrial Reservoir Size and Left Ventricular Untwisting Rate for Predicting Outcome in Primary Mitral Regurgitation.

    PubMed

    Zito, Concetta; Manganaro, Roberta; Khandheria, Bijoy; Oreto, Giuseppe; Cusmà-Piccione, Maurizio; Todaro, Maria Chiara; Caprino, Alessandra; Pugliatti, Pietro; Di Bella, Gianluca; Carerj, Scipione

    2015-10-15

    The present study proposed to evaluate whether analysis of cardiac mechanics through speckle-tracking imaging is useful for risk stratification in asymptomatic patients with chronic primary mitral regurgitation (MR). We prospectively enrolled 67 patients (mean age 57 ± 18 years) and followed them over time. MR was mild in 20 patients (30%), moderate in 24 (36%), and severe in 23 (34%). After a mean time of 24.8 ± 17 months, 34 patients (51%) remained asymptomatic, whereas 33 (49%) developed events (19 underwent mitral valve surgery, 9 required hospitalization for acute heart failure, and 5 patients died). Compared to asymptomatic patients, those with events at baseline showed more severe MR, larger and spherical ventricles, diastolic dysfunction, and greater systolic pulmonary arterial pressure. Moreover, patients with events had decreased left atrial (LA) reservoir (p <0.001) and left ventricular (LV) untwisting rate (p <0.001). On univariate Cox regression analysis, effective regurgitant orifice area (p <0.001), vena contracta (p <0.001), systolic pulmonary arterial pressure (p = 0.003), LV end-systolic diameter (p <0.001), E/E' ratio (p = 0.004), LA volume (p = 0.001), LA reservoir (p <0.001), and LV untwisting rate (p <0.001) were associated with an increased risk of events. On multivariate analysis, only LA reservoir (p = 0.013) and LV untwisting rate were independent predictors (p = 0.017) of outcome. Moreover, LA reservoir evaluation significantly improved (p = 0.013) risk stratification compared to recommended parameters. In conclusion, impaired cardiac mechanics is more closely associated than severity of MR with the occurrence of events in asymptomatic chronic primary MR.

  16. Association of Left Atrial Volume With Mortality Among ESRD Patients With Left Ventricular Hypertrophy Referred for Kidney Transplantation

    PubMed Central

    Patel, Rajan K.; Jardine, Alan G.M.; Mark, Patrick B.; Cunningham, Anthony F.; Steedman, Tracey; Powell, Joanna R.; McQuarrie, Emily P.; Stevens, Kathryn K.; Dargie, Henry J.; Jardine, Alan G.

    2010-01-01

    Background Left ventricular hypertrophy (LVH) is common in patients with end-stage renal disease (ESRD) and an independent risk factor for premature cardiovascular death. Left atrial volume (LAV), measured using echocardiography, predicts death in patients with ESRD. Cardiovascular magnetic resonance (CMR) imaging is a volume-independent method of accurately assessing cardiac structure and function in patients with ESRD. Study Design Single-center prospective observational study to assess the determinants of all-cause mortality, particularly LAV, in a cohort of ESRD patients with LVH, defined using CMR imaging. Setting & Participants 201 consecutive ESRD patients with LVH (72.1% men; mean age, 51.6 ± 11.7 years) who had undergone pretransplant cardiovascular assessment were identified using CMR imaging between 2002-2008. LVH was defined as left ventricular mass index >84.1 g/m2 (men) or >74.6 g/m2 (women) based on published normal left ventricle dimensions for CMR imaging. Maximal LAV was calculated using the biplane area-length method at the end of left ventricle systole and corrected for body surface area. Predictors CMR abnormalities, including LAV. Outcome All-cause mortality. Results 54 patients died (11 after transplant) during a median follow-up of 3.62 years. Median LAV was 30.4 mL/m2 (interquartile range, 26.2-58.1). Patients were grouped into high (median or higher) or low (less than median) LAV. There were no significant differences in heart rate and mitral valve Doppler early to late atrial peak velocity ratio. Increased LAV was associated with higher mortality. Kaplan-Meier survival analysis showed poorer survival in patients with higher LAV (log rank P = 0.01). High LAV and left ventricular systolic dysfunction conferred similar risk and were independent predictors of death using multivariate analysis. Limitations Only patients undergoing pretransplant cardiac assessment are included. Limited assessment of left ventricular diastolic function

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

    PubMed

    Contractor, Tahmeed; Khasnis, Atul

    2011-03-30

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

  18. Percutaneous Closure of the Left Atrial Appendage in Atrial Fibrillation, Second Thoughts?

    PubMed Central

    Wagdi, Philipp; Salzer, Frank

    2012-01-01

    Life expectancy of the population is steadily increasing world wide. Consequently, the incidence and ultimately the prevalence of atrial fibrillation (AF) and it’s sequelae will be rising proportionately. It is estimated that 3-5% of persons above 65 years of age have chronic AF, 30% of which will suffer at least one stroke. On the other hand, chronic AF is responsible for about 20% of all cerebrovascular accidents. Predictors of stroke in AF have been defined by the CHADS2 score, and in these patients, oral anticoagulation has been the cornerstone of thromboembolic disease prevention. Because elderly patients have an increased risk of bleeding complications even under the newer antagonists of Factor Xa and direct Thrombin inhibitors, percutaneous occlusion of the left atrial appendage (LAA) as the main thrombogenic source offers an attractive alternative to permanent anticoagulation. This promising new therapeutic approach is put into clinical real world perspective.

  19. Left atrial appendage occlusion with the WATCHMAN™ for stroke prevention in atrial fibrillation.

    PubMed

    Price, Matthew J

    2014-01-01

    Atrial fibrillation (AF) is a major cause of stroke and systemic embolism. Although warfarin and the novel oral anticoagulants reduce thromboembolic risk, they are associated with an ongoing bleeding hazard, in addition to other limitations that deter their use. The left atrial appendage (LAA) appears to be the primary source of thrombus in AF; therefore, LAA closure represents a mechanical strategy for stroke prevention in these patients. The WATCHMAN™ LAA closure device (Boston Scientific, Natick, MA) is a nitinol-framed occluder that is implanted percutaneously under echocardiographic and fluoroscopic guidance. Data from two randomized clinical trials support the clinical efficacy of transcatheter LAA occlusion with the WATCHMAN and demonstrate that procedural safety has improved significantly since initial experience. This article summarizes the rationale, procedural technique, safety, and clinical efficacy of the WATCHMAN device in patients with AF at high risk for thromboembolic events.

  20. Left atrial appendage exclusion for prevention of stroke in atrial fibrillation: review of minimally invasive approaches.

    PubMed

    Moss, Joshua D

    2014-02-01

    Stroke prevention is of vital importance in the management of atrial fibrillation (AF), though the proven strategy of systemic anticoagulation for thromboembolic prophylaxis is underutilized for a variety of reasons. The left atrial appendage (LAA) has long been suspected as the principal source of arterial emboli, particularly in nonvalvular AF, and a variety of techniques for its exclusion from the circulation have been developed. This review highlights the history of the LAA as a target of intervention, and the parallel advances in three minimally invasive strategies for its exclusion: percutaneous occlusion of the LAA orifice from within the left atrium, closed-chest ligation via a percutaneous pericardial approach, and minimally invasive thoracoscopic surgery. While further study is necessary, available evidence suggests that effective LAA exclusion is becoming a viable alternative to anticoagulation for stroke prevention in nonvalvular AF.

  1. Dynamic characteristic mechanism of atrial septal defect using real-time three-dimensional echocardiography and evaluation of right ventricular functions.

    PubMed

    Sharen, Gao-Wa; Zhang, Jun; Qin, Chuan; Lv, Qing

    2017-02-01

    The dynamic characteristics of the area of the atrial septal defect (ASD) were evaluated using the technique of real-time three-dimensional echocardiography (RT 3DE), the potential factors responsible for the dynamic characteristics of the area of ASD were observed, and the overall and local volume and functions of the patients with ASD were measured. RT 3DE was performed on the 27 normal controls and 28 patients with ASD. Based on the three-dimensional data workstations, the area of ASD was measured at P wave vertex, R wave vertex, T wave starting point, and T wave terminal point and in the T-P section. The right atrial volume in the same time phase of the cardiac cycle and the motion displacement distance of the tricuspid annulus in the corresponding period were measured. The measured value of the area of ASD was analyzed. The changes in the right atrial volume and the motion displacement distance of the tricuspid annulus in the normal control group and the ASD group were compared. The right ventricular ejection fractions in the normal control group and the ASD group were compared using the RT 3DE long-axis eight-plane (LA 8-plane) method. Real-time three-dimensional volume imaging was performed in the normal control group and ASD group (n=30). The right ventricular inflow tract, outflow tract, cardiac apex muscular trabecula dilatation, end-systolic volume, overall dilatation, end-systolic volume, and appropriate local and overall ejection fractions in both two groups were measured with the four-dimensional right ventricular quantitative analysis method (4D RVQ) and compared. The overall right ventricular volume and the ejection fraction measured by the LA 8-plane method and 4D RVQ were subjected to a related analysis. Dynamic changes occurred to the area of ASD in the cardiac cycle. The rules for dynamic changes in the area of ASD and the rules for changes in the right atrial volume in the cardiac cycle were consistent. The maximum value of the changes in the

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  3. Effects of sedation on echocardiographic variables of left atrial and left ventricular function in healthy cats.

    PubMed

    Ward, Jessica L; Schober, Karsten E; Fuentes, Virginia Luis; Bonagura, John D

    2012-10-01

    Although sedation is frequently used to facilitate patient compliance in feline echocardiography, the effects of sedative drugs on echocardiographic variables have been poorly documented. This study investigated the effects of two sedation protocols on echocardiographic indices in healthy cats, with special emphasis on the assessment of left atrial size and function, as well as left ventricular diastolic performance. Seven cats underwent echocardiography (transthoracic two-dimensional, spectral Doppler, color flow Doppler and tissue Doppler imaging) before and after sedation with both acepromazine (0.1 mg/kg IM) and butorphanol (0.25 mg/kg IM), or acepromazine (0.1 mg/kg IM), butorphanol (0.25 mg/kg IM) and ketamine (1.5 mg/kg IV). Heart rate increased significantly following acepromazine/butorphanol/ketamine (mean±SD of increase, 40±26 beats/min) and non-invasive systolic blood pressure decreased significantly following acepromazine/butorphanol (mean±SD of decrease, 12±19 mmHg). The majority of echocardiographic variables were not significantly different after sedation compared with baseline values. Both sedation protocols resulted in mildly decreased left ventricular end-diastolic dimension and mildly increased left ventricular end-diastolic wall thickness. This study therefore failed to demonstrate clinically meaningful effects of these sedation protocols on echocardiographic measurements, suggesting that sedation with acepromazine, butorphanol and/or ketamine can be used to facilitate echocardiography in healthy cats.

  4. Differential changes in atrial natriuretic peptide and vasopressin receptor bindings in kidney of spontaneously hypertensive rat

    SciTech Connect

    Ogura, T.; Mitsui, T.; Yamamoto, I.; Katayama, E.; Ota, Z.; Ogawa, N.

    1987-01-19

    To elucidate the role of atrial natriuretic peptide (ANP) and vasopressin (VP) in a hypertensive state, ANP and VP receptor bindings in spontaneously hypertensive rat (SHR) kidney were analyzed using the radiolabeled receptor assay (RRA) technique. Systolic blood pressure of SHR aged 12 weeks was statistically higher than that of age-matched Wistar Kyoto (WKY) rats. Maximum binding capacity (Bmax) of (/sup 125/I)-ANP binding to the SHR kidney membrane preparations was statistically lower than that of WKY rats, but dissociation constant (Kd) was not significantly different. On the other hand, Bmax of (/sup 3/H)-VP binding to the SHR kidney membrane preparations was statistically higher than that of WKY rats, but Kd were similar. Since the physiological action of ANP is natriuresis and VP is the most important antidiuretic hormone in mammalia, these opposite changes of ANP and VP receptor bindings in SHR kidney suggested that these peptides may play an important role in the pathophysiology of the hypertensive state, although it has not been confirmed as yet.

  5. Strain/strain rate imaging of impaired left atrial function in patients with metabolic syndrome.

    PubMed

    Fang, Ning-Ning; Sui, Dong-Xin; Yu, Jin-Gui; Gong, Hui-Ping; Zhong, Ming; Zhang, Yun; Zhang, Wei

    2015-11-01

    Left ventricular (LV) dysfunction has been demonstrated in patients with metabolic syndrome (MetS). However, alterations in left atrial (LA) function in MetS are unknown. We aimed to use strain/strain rate (SR) imaging to investigate the effect of MetS on LA function. A total of 177 MetS patients and 156 normal subjects underwent echocardiography. Strain and SR tissue Doppler imaging values were used to evaluate LA function. Partial correlation and multiple stepwise regression analyses were used to determine the risk factors for impaired LA function. Compared with the controls, the MetS patients showed significantly lower levels of mean strain, mean peak systolic SR and mean peak early diastolic SR (P<0.001 for all), with no difference in the mean peak late diastolic SR. Central obesity, hypertension, dyslipidemia and LV diastolic abnormality were independent risk factors for impaired LA function. LA function was impaired in patients with MetS as a result of metabolic disturbance and LV diastolic abnormality. SR imaging is reliable in assessing LA function in MetS patients.

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

    PubMed Central

    Sramko, Marek; Wichterle, Dan; Kautzner, Josef

    2016-01-01

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

  7. Role of Endovascular Closure of the Left Atrial Appendage in Stroke Prevention for Atrial Fibrillation.

    PubMed

    Kiani, Jawad; Holmes, David R

    2015-11-01

    The pathophysiologic mechanism of thromboembolic stroke in the setting of non-valvular atrial fibrillation (AF) resides in the left atrial appendage (LAA). In this setting, approximately 90 % of all strokes originate from this structure. Percutaneous left atrial appendage occlusion (LAAO) therapy has recently emerged as an important strategy for prevention of stroke and systemic embolism in patients with non-valvular AF. Systemic anticoagulation therapy in this AF population, while effective, is associated with a significant bleeding risk, drug compliance issues, and limited reversal strategies. In this manuscript, we will review the percutaneous devices and techniques that allow endovascular closure of the LAA, including their efficacy in stroke prevention, the safety profile of these local site-specific therapies, comparison of the multiple approaches being studied, the index patient populations involved, and long-term follow-up in comparison with systemic anticoagulation therapy. The percutaneous LAAO approach indeed represents an exciting and revolutionary advance in the field of stroke prevention in AF.

  8. Event synchronous adaptive filter based atrial activity estimation in single-lead atrial fibrillation electrocardiograms.

    PubMed

    Lee, Jeon; Song, Mi-hye; Shin, Dong-gu; Lee, Kyoung-joung

    2012-08-01

    In this paper, an event synchronous adaptive filter (ESAF) is proposed to estimate atrial activity (AA) from a single-lead AF ECG in real time. The proposed ESAF is a kind of adaptive filter designed to have the reference fed with the impulse train synchronized with the R peak in a raw atrial fibrillation (AF) ECG and to input the timely delayed AF ECG into the primary input. To assess the performance, for ten simulated AF ECGs, the cross-correlation coefficient (ρ) and the normalized mean square error (NMSE) between estimated AAs and ten original simulated AAs were calculated and, for ten real AF ECGs, the ventricular residue (VR) in QRS interval and similarity (S) in non-QRS interval were computed. As a result, these four parameters were revealed as ρ = 0.938 ± 0.016 and NMSE = 0.243 ± 0.051 for simulated AF ECGs and VR = 1.190 ± 0.476 and S = 0.967 ± 0.041 for real AF ECGs. These results were found to be better than those of the averaged beat subtraction (ABS) method, which had been previously considered the only way to estimate AA automatically in real time. In conclusion, even with single-lead AF ECGs, the proposed method estimated AAs accurately and calculated the atrial fibrillatory frequencies, the most valuable index in AF maintenance and therapy evaluation, with a remarkably low computational cost.

  9. Blood pressure control and the reduction of left atrial overload is essential for controlling atrial fibrillation.

    PubMed

    Tanabe, Yasuko; Kawamura, Yuichiro; Sakamoto, Naka; Sato, Nobuyuki; Kikuchi, Kenjiro; Hasebe, Naoyuki

    2009-07-01

    The purpose of this study was to investigate whether the ideal control of atrial fibrillation (AF) associated with hypertensive patients depends on the usage of renin-angiotensin system (RAS) inhibitors or whether it occurs regardless of the kind of antihypertensive agents used. The control of AF was compared in 112 outpatients between 1) those with or without the administration of RAS inhibitors, and 2) those with an ideal or poor control of the blood pressure (BP) regardless of the kind of antihypertensive therapy used. The therapies with or without RAS inhibitors did not yield any significant difference in the AF control states, even though RAS inhibitors had been administered to the patient group with a high proportion of organic heart disease. The ideal BP control group exhibited a significantly better AF control in comparison to the poor BP control group. The former group had a significantly smaller left atrial diameter determined by ultrasonic echocardiography. BP control itself may essentially be important for preventing AF in the general patient population. Poor BP control seemed to have an affect on worsening AF possibly via left ventricular diastolic dysfunction, followed by left atrial overload.

  10. Risk stratification for recurrent heart failure in patients post-myocardial infarction with electrocardiographic and echocardiographic left atrial abnormality.

    PubMed

    Ariyarajah, Vignendra; Malinski, Maciej; Zieroth, Shelley; Harizi, Robert; Morris, Andrew; Spodick, David H

    2008-05-15

    Left atrial enlargement is predictive of cardiovascular events. The predictive power, however, of the combination of electrocardiographic (LAE-ECG) and echocardiographic left atrial enlargement (LAE-Echo) has not been extensively evaluated. We prospectively identified patients admitted with non-ST-segment elevation myocardial infarction (NSTEMI) who developed new-onset heart failure during admission. Baseline electrocardiograms obtained < or =12 months before admission were evaluated for LAE-ECG, such as prolonged P-wave duration or positive P-wave terminal force in lead V1, and in-hospital echocardiographic reports obtained < or =1 month after admission were assessed for linear, anteroposterior LAE-Echo. Follow-up was directed toward pertinent cardiovascular events and death. Of the 462 patients with NSTEMI, 108 developed new-onset heart failure (23%); 71 patients had LAE-Echo. Follow-up was 23.2 months (mean 22.1 months). Although in-hospital (early) cardiovascular complications (other than heart failure) were not significantly higher in patients with LAE-Echo, these patients demonstrated more postdischarge (late) cardiovascular complications, predominantly recurrent heart failure. In addition, those with a combination of LAE-Echo and LAE-ECG demonstrated significantly higher recurrence of heart failure (hazard ratio 1.52, 95% confidence interval 1.12 to 4.35; p = 0.02 for interatrial conduction delay, and hazard ratio 1.07, 95% confidence interval 1.01 to 3.27 for P-wave terminal force in lead V1; p = 0.03) and increased mortality compared with those with LAE-Echo alone. In conclusion, our data suggest that a combination of electrical and mechanical left atrial dysfunction is significantly more predictive of increased cardiovascular events and mortality compared with left atrial mechanical dysfunction alone.

  11. Finite element modeling of the left atrium to facilitate the design of an endoscopic atrial retractor.

    PubMed

    Jernigan, S R; Buckner, G D; Eischen, J W; Cormier, D R

    2007-12-01

    With the worldwide prevalence of cardiovascular diseases, much attention has been focused on simulating the characteristics of the human heart to better understand and treat cardiac disorders. The purpose of this study is to build a finite element model of the left atrium (LA) that incorporates detailed anatomical features and realistic material characteristics to investigate the interaction of heart tissue and surgical instruments. This model is used to facilitate the design of an endoscopically deployable atrial retractor for use in minimally invasive, robotically assisted mitral valve repair. Magnetic resonance imaging (MRI) scans of a pressurized explanted porcine heart were taken to provide a 3D solid model of the heart geometry, while uniaxial tensile tests of porcine left atrial tissue were conducted to obtain realistic material properties for noncontractile cardiac tissue. A finite element model of the LA was constructed using ANSYS Release 9.0 software and the MRI data. The Mooney-Rivlin hyperelastic material model was chosen to characterize the passive left atrial tissue; material constants were derived from tensile test data. Finite element analysis (FEA) models of a CardioVations Port Access retractor and a prototype endoscopic retractor were constructed to simulate interaction between each instrument and the LA. These contact simulations were used to compare the quality of retraction between the two instruments and to optimize the design of the prototype retractor. Model accuracy was verified by comparing simulated cardiac wall deflections to those measured by MRI. FEA simulations revealed that peak forces of approximately 2.85 N and 2.46 N were required to retract the LA using the Port Access and prototype retractors, respectively. These forces varied nonlinearly with retractor blade displacement. Dilation of the atrial walls and rigid body motion of the chamber were approximately the same for both retractors. Finite element analysis is shown to be an

  12. Differential control of systolic and diastolic blood pressure in blacks with essential hypertension.

    PubMed Central

    Ayodele, Olugbenga E.; Alebiosu, C. Olutayo; Salako, Babatunde L.

    2004-01-01

    OBJECTIVE: The risk of cardiovascular and renal diseases has been shown to be higher for systolic blood pressure than diastolic blood pressure. The aim of this study was to assess the differential control of systolic and diastolic blood pressure in Nigerians with primary hypertension. DESIGN AND SETTING: This was a prospective observational study carried out at the Medical Outpatient Department of the State Hospital, Abeokuta, Nigeria. Ethical approval for the study was obtained from the ethical committee of the hospital. METHODOLOGY: The study population consisted of 185 consecutive patients (65 males, 120 females), aged 35-85 years with primary hypertension who had been on drugs one- to 25 years prior to the onset of the study. Clinic blood pressure control was assessed during a year period. Six consecutive clinic blood pressure readings were recorded for each patient and the average calculated (systolic blood pressure and diastolic blood pressure separately). Patients were classified into subgroups based on the pattern of blood pressure control. RESULTS: Clinic systolic blood pressure and diastolic blood pressure was controlled in 58 patients (31.4%). Systolic blood pressure control was less frequent than diastolic blood pressure control (35.7% versus 51.4%, p<0.05). Patients with uncontrolled systolic blood pressure were significantly older than patients with only uncontrolled diastolic blood pressure (66.7+/-7.4 versus 52.9+/-8.7 years, p<0.001). CONCLUSION: Systolic blood pressure is less frequently controlled than diastolic blood pressure in Nigerians treated for primary hypertension. This may increase the patient's risk of developing stroke, and cardiovascular and renal complications. PMID:15040512

  13. Systolic Strain Abnormalities to Predict Hospital Readmission in Patients With Heart Failure and Normal Ejection Fraction

    PubMed Central

    Borer, Steven M.; Kokkirala, Aravind; O'Sullivan, David M.; Silverman, David I.

    2011-01-01

    Background Despite intensive investigation, the pathogenesis of heart failure with normal ejection fraction (HFNEF) remains unclear. We hypothesized that subtle abnormalities of systolic function might play a role, and that abnormal systolic strain and strain rate would provide a marker for adverse outcomes. Methods Patients of new CHF and left ventricular ejection fraction > 50% were included. Exclusion criteria were recent myocardial infarction, severe valvular heart disease, severe left ventricular hypertrophy (septum >1.8 cm), or a technically insufficient echocardiogram. Average peak systolic strain and strain rate were measured using an off-line grey scale imaging technique. Systolic strain and strain rate for readmitted patients were compared with those who remained readmission-free. Results One hundred consecutive patients with a 1st admission for HFNEF from January 1, 2004 through December 31, 2007, inclusive, were analyzed. Fifty two patients were readmitted with a primary diagnosis of heart failure. Systolic strain and strain rates were reduced in both study groups compared to controls. However, systolic strain did not differ significantly between the two groups (-11.7% for those readmitted compared with -12.9% for those free from readmission, P = 0.198) and systolic strain rates also were similar (-1.05 s-1 versus -1.09 s-1, P = 0.545). E/e’ was significantly higher in readmitted patients compared with those who remained free from readmission (14.5 versus 11.0, P = 0.013). E/e’ (OR 1.189, 95% CI 1.026-1.378; P = 0.021) was found to be an independent predictor for HFNEF readmission. Conclusions Among patients with new onset HFNEF, SS and SR rates are reduced compared with patients free of HFNEF, but do not predict hospital readmission. Elevated E/e’ is a predictor of readmission in these patients.

  14. Coronary steal by left atrial myxoma: a case report.

    PubMed

    Alvarez, Jose Rubio; Quiroga, Juan Sierra; Cereijo, Jose Manuel Martinez; Lopez, Laura Reija

    2009-06-18

    This report describes a 41-year-old man who had atypical angina resulting from coronary steal by left atrial myxoma. The tumor was completely excised and the patient was symptoms free after operation.

  15. [Current state of treatment strategies for atrial fibrillation].

    PubMed

    Rogge, C; Hilbert, S; Dagres, N; Hindricks, G

    2016-05-01

    Atrial fibrillation is the most common form of persistent cardiac arrhythmia with a greatly increasing prevalence due to an aging population and increasing cardiovascular risk factors. Apart from impairment of the quality of life atrial fibrillation is associated with a high morbidity, most importantly stroke and heart failure. The therapy is complex and aims at improving symptoms as well as the prevention of thromboembolic complications, heart failure and aggravating comorbidities. Based on individual patient characteristics and symptoms therapy is mainly based on heart rate control by pharmacological means or therapy for maintaining sinus rhythm. This treatment includes antiarrhythmic drugs and catheter ablation. Current research is aimed at the investigation of the electrophysiological mechanisms of recurrent therapy refractive atrial fibrillation and the question whether the maintenance of sinus rhythm can improve the prognosis of atrial fibrillation.

  16. Apixaban for the prevention of stroke in atrial fibrillation.

    PubMed

    Littrell, Rachel; Flaker, Greg

    2012-02-01

    Until recently, pharmaceutical options for stroke prevention in atrial fibrillation were restricted to aspirin or vitamin K antagonist therapy. In recent years development has been underway for alternatives. Apixaban, a direct Factor Xa inhibitor, is orally dosed, target selective and has few known drug or food interactions. As such, it is a member of a new generation of anticoagulants expected to revolutionize the way we approach anticoagulation for stroke prevention in atrial fibrillation. Apixaban has been studied in Phase II and Phase III trials for a variety of indications. The AVERROES trial established apixaban as superior to aspirin for stroke reduction in patients with atrial fibrillation for whom vitamin K antagonist therapy is unsuitable. The recent ARISTOTLE trial found apixaban to be superior to warfarin for stroke prevention in a wide range of patients with atrial fibrillation, with significantly lower bleeding risk, and lower risk of all-cause mortality.

  17. Cardiac adipose tissue and atrial fibrillation: the perils of adiposity.

    PubMed

    Hatem, Stéphane N; Redheuil, Alban; Gandjbakhch, Estelle

    2016-04-01

    The amount of adipose tissue that accumulates around the atria is associated with the risk, persistence, and severity of atrial fibrillation (AF). A strong body of clinical and experimental evidence indicates that this relationship is not an epiphenomenon but is the result of complex crosstalk between the adipose tissue and the neighbouring atrial myocardium. For instance, epicardial adipose tissue is a major source of adipokines, inflammatory cytokines, or reactive oxidative species, which can contribute to the fibrotic remodelling of the atrial myocardium. Fibro-fatty infiltrations of the subepicardium could also contribute to the functional disorganization of the atrial myocardium. The observation that obesity is associated with distinct structural and functional remodelling of the atria has opened new perspectives of treating AF substrate with aggressive risk factor management. Advances in cardiac imaging should lead to an improved ability to visualize myocardial fat depositions and to localize AF substrates.

  18. Successful treatment of atrial tachycardias with flecainide acetate.

    PubMed Central

    Creamer, J E; Nathan, A W; Camm, A J

    1985-01-01

    Intravenous flecainide successfully terminated atrial tachycardia in three patients. Maintenance treatment with oral flecainide prevented the recurrence of tachycardia for up to three years. These results suggest an additional use for flecainide which should be further explored. PMID:3966957

  19. Incidence and Prognosis of Atrial Fibrillation in Patients With Sepsis

    PubMed Central

    Wells, Gretchen L.; Morris, Peter E.

    2011-01-01

    Background Although the mortality rate among patients with sepsis is declining, the incidence of both sepsis and sepsis-related deaths is increasing, likely due to its presence in a growing elderly population. As atrial fibrillation is more common in the elderly, we hypothesize that its presence will be associated with greater mortality among patients with sepsis. Methods The Medical Intensive Care Unit (MICU) database of a large tertiary care medical center was queried for sepsis-related codes and atrial fibrillation. Results Atrial fibrillation was associated with older age and a higher mortality in this series of patients with sepsis. Conclusions Whether atrial fibrillation is a marker of disease severity or contributes to mortality is uncertain. Further studies are necessary to determine optimal management.

  20. The design and rationale of a multi-center clinical trial comparing two strategies for control of systolic blood pressure: The Systolic Blood Pressure Intervention Trial (SPRINT)

    PubMed Central

    2014-01-01

    Background High blood pressure is an important public health concern because it is highly prevalent and a risk factor for adverse health outcomes, including coronary heart disease, stroke, decompensated heart failure, chronic kidney disease, and decline in cognitive function. Observational studies show a progressive increase in risk associated with blood pressure above 115/75 mm Hg. Prior research has shown that reducing elevated systolic blood pressure lowers the risk of subsequent clinical complications from cardiovascular disease. However, the optimal systolic blood pressure to reduce blood pressure-related adverse outcomes is unclear, and the benefit of treating to a level of systolic blood pressure well below 140 mm Hg has not been proven in a large, definitive clinical trial. Purpose To describe the design considerations of the Systolic Blood Pressure Intervention Trial (SPRINT) and the baseline characteristics of trial participants. Methods SPRINT is a multi-center, randomized, controlled trial that compares two strategies for treating systolic blood pressure: one targets the standard target of <140 mm Hg, and the other targets a more intensive target of <120 mm Hg. Enrollment focused on volunteers of age ≥50 years (no upper limit) with an average baseline systolic blood pressure ≥130 mm Hg and evidence of cardiovascular disease, chronic kidney disease, 10-year Framingham cardiovascular disease risk score ≥15%, or age ≥75 years. SPRINT recruitment also targeted three pre-specified subgroups: participants with chronic kidney disease (estimated glomerular filtration rate <60 ml/min/1.73m2), participants with a history of cardiovascular disease, and participants 75 years of age or older. The primary outcome is first occurrence of a myocardial infarction, acute coronary syndrome, stroke, heart failure, or cardiovascular disease death. Secondary outcomes include all-cause mortality, decline in kidney function or development of end-stage renal disease

  1. Atrial fibrillation, progression of coronary atherosclerosis and myocardial infarction.

    PubMed

    Bayturan, Ozgur; Puri, Rishi; Tuzcu, E Murat; Shao, Mingyuan; Wolski, Kathy; Schoenhagen, Paul; Kapadia, Samir; Nissen, Steven E; Sanders, Prashanthan; Nicholls, Stephen J

    2017-03-01

    Background Despite atrial fibrillation representing an established risk factor for stroke, the association between atrial fibrillation and both progression of coronary atherosclerosis and major adverse cardiovascular events is not well characterized. We assessed the serial measures of coronary atheroma burden and cardiovascular outcomes in patients with and without atrial fibrillation. Methods Data were analyzed from nine clinical trials involving 4966 patients with coronary artery disease undergoing serial intravascular ultrasonography at 18-24 month intervals to assess changes in percent atheroma volume (PAV). Using a propensity weighted analysis, and following adjustment for baseline variables, patients with ( n = 190) or without ( n = 4776) atrial fibrillation were compared with regard to coronary plaque volume and major adverse cardiovascular events (death, myocardial infarction, and stroke). Results Atrial fibrillation patients demonstrated lower baseline PAV (36.0 ± 8.9 vs. 38.1 ± 8.9%, p = 0.002) and less PAV progression (-0.07 ± 0.34 vs. + 0.23 ± 0.34%, p = 0.001) compared with the non-atrial fibrillation group. Multivariable analysis revealed atrial fibrillation to independently predict both myocardial infarction [HR, 2.41 (1.74,3.35), p<0.001] 2.41 (1.74, 3.35), p < 0.00) and major adverse cardiovascular events [HR, 2.2, (1.66, 2.92), p<0.001] 2.20 (1.66, 2.92), p < 0.001]. Kaplan-Meier analysis showed that atrial fibrillation compared with non-atrial fibrillation patients had a significantly higher two-year cumulative incidence of overall major adverse cardiovascular events (4.4 vs. 2.0%, log-rank p = 0.02) and myocardial infarction (3.3 vs. 1.5%, log-rank p = 0.05). Conclusions The presence of atrial fibrillation independently associates with a heightened risk of myocardial infarction despite a lower baseline burden and progression rate of coronary atheroma. Further studies are necessary to define

  2. Convergent evolutionary reduction of atrial septation in lungless salamanders.

    PubMed

    Lewis, Zachary R; Hanken, James

    2017-01-01

    Nearly two thirds of the approximately 700 species of living salamanders are lungless. These species respire entirely through the skin and buccopharyngeal mucosa. Lung loss dramatically impacts the configuration of the circulatory system but the effects of evolutionary lung loss on cardiac morphology have long been controversial. For example, there is presumably little need for an atrial septum in lungless salamanders due to the absence of pulmonary veins and the presence of a single source of mixed blood flowing into the heart, but whether lungless salamanders possess an atrial septum and whether the sinoatrial aperture is located in the left or right atrium are unresolved; authors have stated opposing claims since the late 1800s. Here, we use micro-computed tomography (μ-CT) imaging, gross dissection and histological reconstruction to compare cardiac morphology among lungless plethodontid salamanders (Plethodontidae), salamanders with lungs, and the convergently lungless species Onychodactylus japonicus (Hynobiidae). Plethodontid salamanders have partial atrial septa and incomplete separation of the atrium into left and right halves. Partial septation is also seen in O. japonicus. Hence, lungless salamanders from two lineages convergently evolved similar morphology of the atrial septum. The partial septum in lungless salamanders can make it appear that the sinoatrial aperture is in the left atrium, but this interpretation is incorrect. Outgroup comparisons demonstrate that the aperture is located in a posterodorsal extension of the right atrium into the left side of the heart. Independent evolutionary losses of the atrial septum may have a similar developmental basis. In mammals, the lungs induce formation of the atrial septum by secreting morphogens to neighboring mesenchyme. We hypothesize that the lungs induce atrial septum development in amphibians in a similar fashion to mammals, and that atrial septum reduction in lungless salamanders is a direct result

  3. Arterial stiffening precedes systolic hypertension in diet-induced obesity.

    PubMed

    Weisbrod, Robert M; Shiang, Tina; Al Sayah, Leona; Fry, Jessica L; Bajpai, Saumendra; Reinhart-King, Cynthia A; Lob, Heinrich E; Santhanam, Lakshmi; Mitchell, Gary; Cohen, Richard A; Seta, Francesca

    2013-12-01

    Stiffening of conduit arteries is a risk factor for cardiovascular morbidity. Aortic wall stiffening increases pulsatile hemodynamic forces that are detrimental to the microcirculation in highly perfused organs, such as the heart, brain, and kidney. Arterial stiffness is associated with hypertension but presumed to be due to an adaptive response to increased hemodynamic load. In contrast, a recent clinical study found that stiffness precedes and may contribute to the development of hypertension although the mechanisms underlying hypertension are unknown. Here, we report that in a diet-induced model of obesity, arterial stiffness, measured in vivo, develops within 1 month of the initiation of the diet and precedes the development of hypertension by 5 months. Diet-induced obese mice recapitulate the metabolic syndrome and are characterized by inflammation in visceral fat and aorta. Normalization of the metabolic state by weight loss resulted in return of arterial stiffness and blood pressure to normal. Our findings support the hypothesis that arterial stiffness is a cause rather than a consequence of hypertension.

  4. [Spontaneous hematoma of the atrial wall].

    PubMed

    Iglesias López, A; Rodríguez Pan, A; Pazos Silva, V

    2014-01-01

    The clinical signs of heart masses tend to be nonspecific, generally depending more on their repercussions on heart function caused by their location rather than on their type. Imaging techniques make it possible to limit the differential diagnosis of heart masses based on their location, morphology, and characteristics of echogenicity, density, or intensity, depending on the technique used to study them. We present the case of a woman with squeezing mid chest pain irradiating to her shoulder and positive cardiac markers in whom a left atrial mass was identified at echocardiography. This finding was confirmed at chest CT. The signs at chest CT were compatible with a mural hematoma and this diagnosis was confirmed after intraoperative biopsy.

  5. Individualising Anticoagulant Therapy in Atrial Fibrillation Patients

    PubMed Central

    2016-01-01

    Non-vitamin K antagonist (VKA) oral anticoagulants (NOACs) have emerged as alternatives to VKAs for the prevention of stroke in patients with non-valvular atrial fibrillation. Four NOACS: dabigatran, apixaban, rivaroxaban and edoxaban, have received regulatory approval in Europe from the European Medicines Agency. Numerous factors can influence the decision to prescribe a NOAC, the most important of which are assessment of stroke and bleeding risks. Given the variation in design of the pivotal phase III clinical trials investigating the efficacy and safety of NOACs, and in the absence of head-to-head comparative data, it is impossible to recommend one NOAC over the other. However, NOACS offer the opportunity for individualised therapy based on factors such as renal function, age or patient/doctor preference for once- or twice-daily dosing regimens. Dose reduction of some NOACS should be considered in at-risk patient populations. PMID:27617088

  6. [Antenatal atrial tachycardia. Two case reports].

    PubMed

    Pavlova, M; Lupoglazoff, J M; Denjoy, I; Luton, D; Magnier, S; Casasoprana, A; Azancot, A

    2001-05-01

    The authors report two cases of foetal supraventricular tachycardia in healthy hearts with 1/1 atrioventricular conduction which turned out to be atrial tachycardias in the postnatal period. The first foetus had permanent tachycardia at 190/minute at 34 weeks' amenorrhea with left ventricular dysfunction at 36 weeks. In the postnatal period, treatment with digoxine and amiodarone restored sinus rhythm and normal left ventricular function. Permanent foetal tachycardia, even at a rate of less than 200 beats/minute, should suggest an arrhythmia and may lead to left ventricular dysfunction in utero. The other foetus had an aneurysm of the foramen ovale with paroxysmal tachycardias at 220/minute without cardiac dysfunction. A Holter at 1 month showed paroxysmalatrial tachycardia. Postnatal rhythm monitoring is necessary in paroxysmal foetus tachycardia, especially with prenatal aneurysm of the foramen ovale.

  7. Pharmacological Tests in Atrial Fibrillation Ablation

    PubMed Central

    Gourraud, Jean-Baptiste; Andrade, Jason G; Macle, Laurent

    2016-01-01

    The invasive management of atrial fibrillation (AF) has been considerably changed by the identification of major sites of AF initiation and/or maintenance within the pulmonary vein antra. Percutaneous catheter ablation of these targets has become the standard of care for sustained maintenance of sinus rhythm. Long-term failure of ablation is related to an inability to create a durable transmural lesion or to identify all of the non-pulmonary vein arrhythmia triggers. Pharmacological challenges during catheter ablation have been suggested to improve outcomes in both paroxysmal and persistent AF. Herein we review the mechanism and evidence for the use of pharmacological adjuncts during the catheter ablation of AF. PMID:28116081

  8. Atrial Fibrillation, Cognitive Decline And Dementia

    PubMed Central

    Alonso, Alvaro; Arenas de Larriva, Antonio P.

    2016-01-01

    Atrial fibrillation (AF) is a common cardiac arrhythmia. Growing evidence supports a role for AF as a risk factor for cognitive decline and dementia. In this review, we summarize epidemiologic observations linking AF with cognitive outcomes, describe potential mechanisms, and explore the impact of AF treatments on cognitive decline and dementia. Community-based, observational studies show a consistent higher rate of cognitive decline and risk of dementia in persons with AF. These associations are partly due to the increased risk of clinical stroke in AF, but other mechanisms, including incidence of silent cerebral infarcts, microbleeds, and cerebral hypoperfusion, are likely additional contributors. Adequate oral anticoagulation and improved management of the overall cardiovascular risk profile in persons with AF offer the promise of reducing the impact of AF on cognitive decline and dementia. PMID:27547248

  9. Perspectives and controversies in atrial fibrillation.

    PubMed

    Prystowsky, E N

    1998-08-20

    Atrial fibrillation (AF) is the most common sustained arrhythmia in humans. The 3 basic tenets of therapy are (1) restoration and maintenance of sinus rhythm; (2) ventricular rate control; and (3) prevention of thromboembolism. Maintenance of sinus rhythm appears preferable to rate control alone in patients with significant symptoms caused by AF. Complete suppression of AF with drug therapy for >6 months is unusual, but it is not the sole criterion of success. As with other chronic cardiac disorders such as angina and heart failure, a marked reduction in frequency and duration of episodes of AF will likely translate into an excellent clinical outcome. The major risk of antiarrhythmic drug therapy is ventricular proarrhythmia, which is seen most frequently in patients with substantial left ventricular dysfunction. Torsade de pointes is the most frequent proarrhythmia that occurs with antiarrhythmic agents that prolong ventricular repolarization and the QT interval. To minimize the risk of proarrhythmia, antiarrhythmic drugs are started in-hospital in patients with significant heart disease, and agents are selected based on certain patient characteristics. For example, the drugs initially selected for patients with heart failure and coronary artery disease are amiodarone and sotalol, respectively. Two approaches may be used to decrease the thromboembolic risk associated with cardioversion of AF to sinus rhythm. In the conventional method, warfarin is given (INR 2.0-3.0) for 3 weeks before and at least 4 weeks after cardioversion. An alternative approach employs transesophageal echocardiography to rule out left atrial thrombi before cardioversion. Both methods appear reasonable and safe, and I prefer the conventional and transesophageal echocardiography-guided approaches for outpatients and in-hospital patients, respectively.

  10. Automatic Detection of Atrial Fibrillation Using Basic Shannon Entropy of RR Interval Feature

    NASA Astrophysics Data System (ADS)

    Afdala, Adfal; Nuryani, Nuryani; Satriyo Nugroho, Anto

    2017-01-01

    Atrial Fibrillation is one of heart disease, that common characterized by irregularity heart beat. Atrial fibrillation leads to severe complications such as cardiac failure with the subsequent risk of a stroke. A method to detect atrial fibrillation is needed to prevent a risk of atrial fibrillation. This research uses data from physionet in atrial fibrillation database category. The performance of Shannon entropy has the highest accuracy if a threshold is 0.5 with accuracy 89.79%, sensitivity 91.04% and specificity 89.01%. Based on the result we get a conclusion, the ability of Shannon entropy to detect atrial fibrillation is good.

  11. Reflex effects on the heart of stimulating left atrial receptors

    PubMed Central

    Furnival, C. M.; Linden, R. J.; Snow, H. M.

    1971-01-01

    1. Stimulation of left atrial receptors, by distension of the pulmonary vein/left atrial junctions, is known to cause a reflex increase in heart rate; the efferent pathway is known to be solely in the sympathetic nerves. 2. In expectation of a concomitant positive inotropic response the effect of stimulating the left atrial receptors on the inotropic state of the left ventricle was studied, using as a known sensitive index of inotropic changes the maximal rate of rise of pressure in the left ventricle (dP/dt max). 3. Stimulation of left atrial receptors resulted in an increase in heart rate but there were no significant concomitant changes in dP/dt max. 4. It is concluded that activity in this discrete efferent pathway does not include an inotropic effect on the left ventricle and therefore the reflex involves only those sympathetic nerves which innervate the sinu-atrial node. 5. The possible function of atrial receptors in the regulation of heart volumes is discussed. PMID:5124571

  12. Distinct pharmacologic substrate in lidocaine-sensitive, repetitive atrial tachycardia.

    PubMed

    Chiale, Pablo A; Faivelis, Luciano; Garro, Hugo A; Fernández, Pablo A; Herrera Paz, Juan J; Elizari, Marcelo V

    2012-06-01

    Lidocaine-sensitive, repetitive atrial tachycardia is an uncommon arrhythmia. The electrophysiologic substrate is still unknown, and the pharmacologic responses have not been fully explored. The aim of this study was to investigate the effects of intravenous adenosine and verapamil in patients with lidocaine-sensitive atrial tachycardia. In 9 patients with repetitive uniform atrial tachycardia, the response to intravenous adenosine (12 mg), lidocaine (1 mg/kg body weight), and verapamil (10 mg) were sequentially investigated. Simultaneous 12-lead electrocardiogram (ECG) was recorded at baseline and continuously monitored thereafter. Tracings were obtained at regularly timed intervals right after the administration of each drug to evaluate changes in the arrhythmia characteristics. Repetitive atrial tachycardia was abolished by intravenous lidocaine in the 9 patients within the first 2 minutes after the end of injection. Adenosine suppressed the arrhythmia in 2 patients and shortened the runs of atrial ectopic activity in 1 patient, while verapamil was effective in 2 patients, 1 of them insensitive to adenosine and the other 1 sensitive to this agent. In 5 patients, the arrhythmia was abolished by radiofrequency ablation at different sites of the right atrium. Lidocaine-sensitive atrial tachycardia may eventually be also suppressed by adenosine and/or verapamil. This suggests that this enigmatic arrhythmia may be caused by different underlying electrophysiologic substrates and that at least in some cases, delayed afterdepolarizations seem to play a determining role.

  13. Hybrid therapy in the management of atrial fibrillation.

    PubMed

    Starek, Zdenk; Lehar, Frantisek; Jez, Jiri; Wolf, Jiri; Novák, Miroslav

    2015-01-01

    Atrial fibrillation is the most common sustained arrhythmia. Because of the sub-optimal outcomes and associated risks of medical therapy as well as the recent advances in non-pharmacologic strategies, a multitude of combined (hybrid) algorithms have been introduced that improve efficacy of standalone therapies while maintaining a high safety profile. Antiarrhythmic administration enhances success rate of electrical cardioversion. Catheter ablation of antiarrhythmic drug-induced typical atrial flutter may prevent recurrent atrial fibrillation. Through simple ablation in the right atrium, suppression of atrial fibrillation may be achieved in patients with previously ineffective antiarrhythmic therapy. Efficacy of complex catheter ablation in the left atrium is improved with antiarrhythmic drugs. Catheter ablation followed by permanent pacemaker implantation is an effective and safe treatment option for selected patients. Additional strategies include pacing therapies such as atrial pacing with permanent pacemakers, preventive pacing algorithms, and/or implantable dual-chamber defibrillators are available. Modern hybrid strategies combining both epicardial and endocardial approaches in order to create a complex set of radiofrequency lesions in the left atrium have demonstrated a high rate of success and warrant further research. Hybrid therapy for atrial fibrillation reviews history of development of non-pharmacological treatment strategies and outlines avenues of ongoing research in this field.

  14. Management of Atrio-Esophageal Fistula Following Left Atrial Ablation

    PubMed Central

    Yousuf, Tariq; Keshmiri, Hesam; Bulwa, Zachary; Kramer, Jason; Sharjeel Arshad, Hafiz Muhammad; Issa, Rasha; Woznicka, Daniel; Gordon, Paul; Abi-Mansour, Pierre

    2016-01-01

    Currently, no guidelines have been established for the treatment of atrio-esophageal fistula (AEF) secondary to left atrial ablation therapy. After comprehensive literature review, we aim to make suggestions on the management of this complex complication and also present a case series. We performed a review of the existing literature on AEF in the setting of atrial ablation. Using keywords atrial fibrillation, atrial ablation, fistula formation, atrio-esophageal fistula, complications, interventions, and prognosis, a search was made using the medical databases PUBMED and MEDLINE for reports in English from 2000 to April 2015. A statistical analysis was performed to compare the three different intervention arms: medical management, stent placement and surgical intervention. The results of our systematic review confirm the high mortality rate associated with AEF following left atrial ablation and the necessity to diagnose atrio-esophageal injury in a timely manner. The mortality rates of this complication are 96% with medical management alone, 100% with stent placement, and 33 % with surgical intervention. Atrio-esophageal injury and subsequent AEF is an infrequent but potentially fatal complication of atrial ablation. Early, prompt, and definitive surgical intervention is the treatment of choice. PMID:28197267

  15. Diastolic, systolic and sarcoplasmic reticulum [Ca2+] during inotropic interventions in isolated rat myocytes.

    PubMed Central

    Frampton, J E; Orchard, C H; Boyett, M R

    1991-01-01

    1. The fluorescent indicator Fura-2 has been used to monitor intracellular [Ca2+] (Ca2+i) in myocytes isolated from the ventricles of rat hearts. 2. The relationships between diastolic Ca2+i, systolic Ca2+i and the Ca2+ content of the sarcoplasmic reticulum (SR; assayed using caffeine) have been studied during changes of stimulation rate and bathing [Ca2+] (Ca2+o). 3. When stimulation rate was increased, there were increases in diastolic Ca2+i, systolic Ca2+i and the Ca2+ content of the SR. 4. The SR inhibitor ryanodine (1 mumol l-1) decreased the size of the Ca2+i transient, and abolished the increase of Ca2+i produced by caffeine (10 mmol l-1). In the presence of ryanodine, increasing stimulation rate increased diastolic Ca2+i but not systolic Ca2+i. 5. Increasing Ca2+o led to increases of diastolic Ca2+i, systolic Ca2+i and SR Ca2+ content similar to those observed during changes in stimulation rate. 6. Ryanodine altered the relationship between systolic and diastolic Ca2+i during changes of Ca2+o. 7. These results are consistent with a change of diastolic Ca2+i leading to an increase in the Ca2+ content of the SR, and hence an increase in the size of the Ca2+i transient during changes in stimulation rate and Ca2+o. Images Fig. 1 Fig. 4 Fig. 10 PMID:1890639

  16. Variability of maximum systolic amplitude of ΔZ/Δt curve in pregnancy. Perennial observations

    NASA Astrophysics Data System (ADS)

    Ilyin, I.; Karpov, A.; Korotkova, M.

    2010-04-01

    Maximum systolic amplitude is quite an important component of the impedance cardiogram ΔZ/Δt curve. Its values make it possible to calculate many hemodynamic indices. Therefore it is necessary to keep informed about monthly, annual and perennial maximum systolic amplitude trend. We can produce the measuring data of the maximum systolic amplitude for a fifteen-year period (from 1994 to 2009). The impedance cardiograms were obtained with the help of an electric impedance analyzer "RA-5" (1 mA, 70 kHz) with disk ECG electrodes. The data analyzed were taken from the pregnant women with non-complicated pregnancy (n=5709). We have analyzed the average monthly and annual changes of the maximum systolic amplitude ΔZ/Δt curve. It allowed us to reveal the six-year periodicity of the maximum systolic amplitude changes. There were discovered statistically significant peak values difference of the amplitude (p>0.001). The data obtained should be taken into consideration when using impedance cardiography in clinical practice. The article is supplied with tables and diagrams.

  17. Rapid changes in rate-corrected and uncorrected systolic time intervals during cold pressor test.

    PubMed

    Mäntysaari, M; Antila, K; Peltonen, T

    1985-02-01

    The changes in heart rate and systolic time intervals were studied in a group of 10 young healthy male volunteers during immersion of their hand in ice water for 1 min. The heart rate and systolic time intervals were measured from electro-, phono-, and impedance cardiograms in the standard way. When the cold immersion was done in the supine position the left ventricular ejection time (LVET) and the electromechanic systole (Q-S2Tc) shortened, and when corrected for the heart rate the Q-S2Tc lengthened in the beginning of the immersion. In the head-up position the Q-S2T shortened in the beginning of the immersion while the rate-corrected systolic time intervals remained unchanged. Most of the changes in the systolic time intervals disappeared before the last quarter of the cold immersion. It was observed that during the cold immersion the linear regression coefficients between the heart rate and the Q-S2T in the supine position as well as between the heart rate and the LVET, Q-S2T and the PEP in the head-up position were greater than the regression coefficients used in the rate correction.

  18. [Atrial fibrillation and regular tachycardia in two young patients--are both treated with atrial fibrillation ablation?].

    PubMed

    von Bodman, G; Brömsen, J; Kopf, C; Füller, M; Block, M

    2014-04-17

    Two young patients with documented episodes of symptomatic paroxysmal atrial fibrillation have been referred for pulmonary vein isolation. Both patients had a history of concomitant regular tachycardia. in both cases pulmonaryvein isolation has not been performed but in each patient a supraventricular tachycardia (right focal atrial tachycardia/atrioventricular reentry tachycardia) could be induced and ablated instead. Concomitant supraventricular tachycardia acting as a trigger arrhythmia is frequent in young patients with atrial fibrillation without underlying cardiacdisease. In these patients a concomitant supra-ventricular tachycardia should beexcluded by electrophysiological study or ablated before pulmonary vein isolation or initiating an antiarrhythmic drug therapy. In most cases ablation of supraventricular tachycardia is safe and successful whereas the risks of ablative therapy of atrial fibrillation can not be neglected and success is moderate.

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

    PubMed

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

    2012-01-01

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

  20. The effect of atrial preference pacing on atrial fibrillation electrophysiological substrate in Myotonic Dystrophy type 1 population.

    PubMed

    Russo, Vincenzo; Nigro, Gerardo; DI Meo, Federica; Papa, Andrea Antonio; Cioppa, Nadia Della; Proietti, Riccardo; Russo, Maria Giovanna; Calabrò, Raffaele; Politano, Luisa

    2014-12-01

    P-wave dispersion is a non invasive indicator of intra-atrial conduction heterogeneity producing substrate for reentry, which is a pathophysiological mechanism of atrial fibrillation. The relationship between P-wave dispersion (PD) and atrial fibrillation (AF) in Myotonic dystrophy type 1 (DM1) patients is still unclear. Atrial Preference Pacing (APP) is an efficient algorithm to prevent paroxysmal AF in patients implanted with dual-chamber pacemaker. Aim of our study was to evaluate the possible correlation between atrial preference pacing algorithm, P-wave dispersion and AF burden in DM1 patients with normal cardiac function underwent permanent dual-chamber pacemaker implantation. We enrolled 50 patients with DM1 (age 50.3 ± 7.3; 11 F) underwent dual-chamber pacemaker implantation for various degree of atrioventricula block. The study population was randomized following 1 months stabilization period to APP algorithm features programmed OFF or ON. Patients were assessed every 3 months for the first year, and every 6 months thereafter up to 3 years. At each follow-up visit, we counted: the number of premature atrial beats, the number and the mean duration of AF episodes, AF burden and the percentage of atrial and ventricular pacing. APP ON Group showed lower number of AF episodes (117 ± 25 vs. 143 ± 37; p = 0.03) and AF burden (3059 ± 275 vs. 9010 ± 630 min; p < 0.04) than APP OFF Group. Atrial premature beats count (44903 ± 30689 vs. 13720 ± 7717 beats; p = 0.005) and Pwave dispersion values (42,1 ± 11 ms vs. 29,1 ± 4,2 ms, p = 0,003) were decreased in APP ON Group. We found a significant positive correlation between PD and AF burden (R = 0,8, p = 0.007). Atrial preference pacing algorithm, decreasing the number of atrial premature beats and the P-wave dispersion, reduces the onset and perpetuator factors of AF episodes and decreases the AF burden in DM1 patients underwent dual chamber pacemaker implantation for various degree of atrioventricular blocks

  1. Pro-atrial natriuretic peptide and prediction of atrial fibrillation and stroke: The Malmö Preventive Project.

    PubMed

    Berntsson, John; Smith, J Gustav; Nilsson, Peter M; Hedblad, Bo; Melander, Olle; Engström, Gunnar

    2017-01-01

    Background The increasing prevalence of atrial fibrillation and novel therapeutic tools to prevent cardioembolic stroke has increased the need for risk markers. Objectives This study explored the relationship between the midregional sequence of pro-atrial natriuretic peptide (MR-proANP) levels with the risk of atrial fibrillation and stroke, and whether measurement of MR-proANP improves the prediction of these outcomes. Methods MR-proANP was measured in fasting blood samples of 5130 subjects (69% men, mean age 69.2 ± 6.2 years) without a history of atrial fibrillation or stroke from the general population. The incidence of atrial fibrillation and stroke was monitored over a median follow-up of 5.6 years. C-statistics and net reclassification improvement was used to assess the predictive ability of MR-proANP in addition to conventional risk factors. Results Log-normalized MR-proANP was significantly associated with the incidence of atrial fibrillation ( n = 362; hazard ratio (HR); 95% confidence interval (CI) per 1 standard deviation (SD) 2.05, 1.86-2.27) and stroke from all causes ( n = 195; HR 1.30; 95% CI 1.12-1.50). The HR for stroke events related to atrial fibrillation was 1.79 (95% CI 1.25-2.58) per 1 SD. MR-proANP significantly improved the prediction of atrial fibrillation when added to a risk score of conventional risk factors (C statistic 0.69 vs. 0.75), mainly by down-classifying subjects who did not develop atrial fibrillation. A smaller improvement in predictive ability was observed for stroke (C statistic 0.66 vs. 0.68). Conclusion High plasma levels of MR-proANP are associated with the incidence of atrial fibrillation and stroke in the middle-aged and elderly population. MR-proANP may be useful to identify individuals with an increased risk of atrial fibrillation.

  2. Excessive interatrial adiposity is associated with left atrial remodeling, augmented contractile performance in asymptomatic population

    PubMed Central

    Lai, Yau-Huei; Yun, Chun-Ho; Su, Cheng-Huang; Yang, Fei-Shih; Yeh, Hung-I; Hou, Charles Jia-Yin; Wu, Tung-Hsin; Cury, Ricardo C; Bezerra, Hiram G

    2016-01-01

    Abstract Purpose Pericardial adipose tissue had been shown to exert local effects on adjacent cardiac structures. Data regarding the mechanistic link between such measures and left atrial (LA) structural/functional remodeling, a clinical hallmark of early stage heart failure (HF) and atrial fibrillation (AF) incidence, in asymptomatic population remain largely unexplored. Methods This retrospective analysis includes 356 subjects free from significant valvular disorders, atrial fibrillation, or clinical HF. Regional adipose tissue including pericardial and periaortic fat volumes, interatrial septal (IAS), and left atrioventricular groove (AVG) fat thickness were all measured by multidetector computed tomography (MDCT) (Aquarius 3D Workstation, TeraRecon, San Mateo, CA, USA). We measured LA volumes, booster performance, reservoir capacity as well as conduit function, and analyzed their association with adiposity measures. Results All four adiposity measures were positively associated with greater LA volumes (all P < 0.05), while IAS and AVG fat were also related to larger LA kinetic energy and worse reservoir capacity (both P < 0.01). In multivariate models, IAS fat thickness remained independently associated with larger LA volumes, increased LA kinetic energy and ejection force (β-coef: 0.17 & 0.15, both P < 0.05), and impaired LA reservoir and conduit function (β-coef: −0.20 & −0.12, both P < 0.05) after adjusting for clinical variables. Conclusion Accumulated visceral adiposity, especially interatrial fat depots, was associated with certain LA structural/functional remodeling characterized by impaired LA reservoir and conduit function though augmented kinetic energy and ejection performance. Our data suggested that interatrial fat burden may be associated with certain detrimental LA functions with compensatory LA adaptation in an asymptomatic population. PMID:27249809

  3. The Effect of Aggressive Blood Pressure Control on the Recurrence of Atrial Fibrillation After Catheter Ablation: A Randomized, Open Label, Clinical Trial (Substrate Modification with Aggressive Blood Pressure Control: SMAC- AF).

    PubMed

    Parkash, Ratika; Wells, George A; Sapp, John L; Healey, Jeffrey S; Tardif, Jean-Claude; Greiss, Isabelle; Rivard, Léna; Roux, Jean-Francois; Gula, Lorne; Nault, Isabelle; Novak, Paul G; Birnie, David H; Ha, Andrew C; Wilton, Stephen B; Mangat, Iqwal; Gray, Christopher J; Gardner, Martin J; Tang, Anthony S L

    2017-02-22

    Background -Radiofrequency catheter ablation for atrial fibrillation has become an important therapy for AF, however recurrence rates remain high. We proposed to determine whether aggressive blood pressure (BP) lowering prevents recurrent atrial fibrillation (AF) after catheter ablation in patients with AF and a high symptom burden. Methods -We randomly assigned 184 patients with AF and a BP greater than 130/80 mmHg to aggressive BP (target <120/80 mm Hg) or standard BP treatment (target <140/90 mmHg) prior to their scheduled AF catheter ablation. The primary outcome was symptomatic recurrence of AF/atrial tachycardia/atrial flutter lasting greater than 30 seconds, determined 3 months beyond catheter ablation by a blinded endpoint evaluation. Results -The median follow-up was 14 months. At six months, the mean systolic BP in the aggressive BP treatment group was 123.2±13.2 versus 135.4±15.7mm Hg (p<0.001) in the standard treatment group. The primary outcome occurred in 106 patients, 54 (61.4%) in the aggressive BP treatment group, compared to 52 (61.2%) in the standard treatment group, (Hazard Ratio 0.94, 95% Confidence Interval 0.65-1.38, p=0.763). In the prespecified subgroup analysis of the influence of age, patients aged ≥ 61 years had a lower primary outcome event rate with aggressive BP (Hazard Ratio 0.58, 95% Confidence Interval (0.34, 0.97), p=0.013). There was a higher rate of hypotension requiring medication adjustment in the aggressive BP group (26% versus 0%). Conclusions -In this study, this duration of aggressive BP treatment did not reduce atrial arrhythmia recurrence after catheter ablation for AF, but resulted in more hypotension. Clinical Trial Registration -Clinicaltrials.gov Identifier: NCT00438113.

  4. Protective effects of epigallocatechin-3 gallate on atrial electrical and structural remodeling in a rabbit rapid atrial pacing model.

    PubMed

    Zhu, Jifa; Zhang, Xiao; Li, Ling; Su, Gang

    2015-03-01

    Epigallocatechin-3 gallate (EGCG) is the major catechin in green tea. The aim of this study is to investigate the effects of EGCG on atrial electrical and structural remodeling in a rabbit rapid atrial pacing (RAP) model. New Zealand white rabbits were subjected to RAP with or without EGCG treatment. The atrial electrophysiology was studied. ELISA, Western blots, and RT-PCR were performed to determine the level of the inflammation markers, oxidative stress, and fibrogenic agents. Atrial tissue was stained with Masson's trichrome stain for fibrosis detection. RAP rabbits showed a significantly shorter atrial effective refractory period than control rabbits. Higher AF inducibility and longer AF duration were seen in the RAP group. AERP of rabbits received high dose EGCG were prolonged compared to RAP rabbits, and AF inducibility and duration of rabbits received high dose EGCG were lower. RAP rabbits have higher inflammation markers, higher oxidative stress, and more significant fibrosis within atrium, while high dose intervention of EGCG can lower the inflammation, oxidative stress, and fibrosis induced by RAP. Results showed that EGCG have protective effects on atrial electrical and structural remodeling in a rabbit RAP model in terms of attenuating of inflammation and oxidative stress.

  5. Atrial Substrate Modification in Atrial Fibrillation: Targeting GP or CFAE? Evidence from Meta-Analysis of Clinical Trials

    PubMed Central

    Qin, Mu; Liu, Xu; Wu, Shao-Hui; Zhang, Xiao-Dong

    2016-01-01

    Several clinically relevant outcomes post atrial substrate modification in patients with atrial fibrillation (AF) have not been systematically analyzed among published studies on adjunctive cardiac ganglionated plexi (GP) or complex fractionated atrial electograms (CFAE) ablation vs. pulmonary vein isolation (PVI) alone. Out of 176 reports identified, the present meta-analysis included 14 randomized and non-randomized controlled trials (1613 patients) meeting inclusion criteria. Addition of GP ablation to PVI significantly increased freedom from atrial tachyarrhythmia in short- (OR: 1.72; P = 0.003) and long-term (OR: 2.0, P = 0.0006) follow-up, while adjunctive CFAE ablation did not after one or repeat procedure (P<0.05). The percentage of atrial tachycardia or atrial flutter (AT/AFL) after one procedure was higher for CFAE than GP ablation. In sub-analysis of non-paroxysmal AF, relative to PVI alone, adjunctive GP but not CFAE ablation significantly increased sinus rhythm maintenance (OR: 1.88, P = 0.01; and OR:1.24, P = 0.18, respectively). Meta regression analysis of the 14 studies indicated that sample size was significant source of heterogeneity either in outcomes after one or repeat procedure. In conclusion, in patients with AF, adjunctive GP but not CFAE ablation appeared to significantly add to the beneficial effects on sinus rhythm maintenance of PVI ablation alone; and CFAE ablation was associated with higher incidence of subsequent AT/AFL. PMID:27764185

  6. Atrial Substrate Modification in Atrial Fibrillation: Targeting GP or CFAE? Evidence from Meta-Analysis of Clinical Trials.

    PubMed

    Qin, Mu; Liu, Xu; Wu, Shao-Hui; Zhang, Xiao-Dong

    2016-01-01

    Several clinically relevant outcomes post atrial substrate modification in patients with atrial fibrillation (AF) have not been systematically analyzed among published studies on adjunctive cardiac ganglionated plexi (GP) or complex fractionated atrial electograms (CFAE) ablation vs. pulmonary vein isolation (PVI) alone. Out of 176 reports identified, the present meta-analysis included 14 randomized and non-randomized controlled trials (1613 patients) meeting inclusion criteria. Addition of GP ablation to PVI significantly increased freedom from atrial tachyarrhythmia in short- (OR: 1.72; P = 0.003) and long-term (OR: 2.0, P = 0.0006) follow-up, while adjunctive CFAE ablation did not after one or repeat procedure (P<0.05). The percentage of atrial tachycardia or atrial flutter (AT/AFL) after one procedure was higher for CFAE than GP ablation. In sub-analysis of non-paroxysmal AF, relative to PVI alone, adjunctive GP but not CFAE ablation significantly increased sinus rhythm maintenance (OR: 1.88, P = 0.01; and OR:1.24, P = 0.18, respectively). Meta regression analysis of the 14 studies indicated that sample size was significant source of heterogeneity either in outcomes after one or repeat procedure. In conclusion, in patients with AF, adjunctive GP but not CFAE ablation appeared to significantly add to the beneficial effects on sinus rhythm maintenance of PVI ablation alone; and CFAE ablation was associated with higher incidence of subsequent AT/AFL.

  7. Resting Energy Expenditure and Systolic Blood Pressure Relationships in Women Across 4.5 Years

    PubMed Central

    Sriram, Neeraj; Hunter, Gary R.; Fisher, Gordon; Brock, David W.

    2014-01-01

    Recent studies have reported a strong association between blood pressure (BP) and resting energy expenditure (REE). However, it is not known if this relationship persists over time. Therefore, we examined the temporal relationship between REE and systolic BP. Additionally, we examined the impact of sympathetic tone and anthropometric variables on this relationship. All testing was performed on healthy, overweight African American and European American women aged 25 – 45 years over 4.5 years in the UAB General Clinical Research Center. Repeated measures mixed-models revealed REE as a significant determinant of systolic BP (β=0.0155, P<0.0001), independent of catecholamines, leg fat, visceral fat, fat free mass, fat mass, height, RSMI, and resting heart rate. Observations that REE is predictive of systolic BP across 4.5 years support previous findings that REE may potentially mediate resting BP, independent of anthropometric variables and a marker for sympathetic tone. PMID:24548382

  8. Sudden Cardiac Arrest in Patients with Preserved Left Ventricular Systolic Function: A Clinical Dilemma

    PubMed Central

    Sawhney, Navinder; Narayan, Sanjiv M.

    2009-01-01

    Stratifying the risk for sudden cardiac arrest (SCA) in individuals with preserved systolic function remains a pressing public health problem. Current guidelines for the implantation of cardiac defibrillators largely ignore patients with preserved systolic function, even though they account for the majority of cases. However, risk stratification for such individuals is increasingly feasible. Notably, most individuals who experience SCA have structural heart disease, even if undiagnosed. Thus, clinical risk scores have been developed to identify high risk. Moreover, there are now promising data that T-Wave Alternans (TWA), alone and in combination with other indices, effectively predicts SCA in this population. This article presents our current understanding of SCA due to ventricular arrhythmias in patients with preserved LV systolic function, and attempts to build a framework to predict risk in this population. PMID:19251226

  9. Brachial vs. central systolic pressure and pulse wave transmission indicators: a critical analysis.

    PubMed

    Izzo, Joseph L

    2014-12-01

    This critique is intended to provide background for the reader to evaluate the relative clinical utilities of brachial cuff systolic blood pressure (SBP) and its derivatives, including pulse pressure, central systolic pressure, central augmentation index (AI), and pulse pressure amplification (PPA). The critical question is whether the newer indicators add sufficient information to justify replacing or augmenting brachial cuff blood pressure (BP) data in research and patient care. Historical context, pathophysiology of variations in pulse wave transmission and reflection, issues related to measurement and model errors, statistical limitations, and clinical correlations are presented, along with new comparative data. Based on this overview, there is no compelling scientific or practical reason to replace cuff SBP with any of the newer indicators in the vast majority of clinical situations. Supplemental value for central SBP may exist in defining patients with exaggerated PPA ("spurious systolic hypertension"), managing cardiac and aortic diseases, and in studies of cardiovascular drugs, but there are no current standards for these possibilities.

  10. Partitioning: An essential step in mapping algorithms into systolic array processors

    SciTech Connect

    Navarro, J.J.; Llaberia, J.M.; Valero, M.

    1987-07-01

    Many scientific and technical applications require high computing speed; those involving matrix computations are typical. For applications involving matrix computations, algorithmically specialized, high-performance, low-cost architectures have been conceived and implemented. Systolic array processors (SAPs) are a good example of these machines. An SAP is a regular array of simple processing elements (PEs) that have a nearest-neighbor interconnection pattern. The simplicity, modularity, and expandability of SAPs make them suitable for VLSI/WSI implementation. Algorithms that are efficiently executed on SAPs are called systolic algorithms (SAs). An SA uses an array of systolic cells whose parallel operations must be specified. When an SA is executed on an SAP, the specified computations of each cell are carried out by a PE of the SAP.

  11. Atrial fibrillation among patients under investigation for suspected obstructive sleep apnea

    PubMed Central

    Sundqvist, Martin; Sandström, Herbert; Sahlin, Carin; Rohani, Morteza; Al-Khalili, Faris; Hörnsten, Rolf; Blomberg, Anders; Wester, Per; Rosenqvist, Mårten; Franklin, Karl A.

    2017-01-01

    Study objectives Obstructive sleep apnea is common among patients with atrial fibrillation, but the prevalence and risk factors for atrial fibrillation among patients who are being investigated on suspicion of sleep apnea are not well known. The aim of the study was to estimate the prevalence of atrial fibrillation among patients investigated for suspected obstructive sleep apnea and to identify risk factors for atrial fibrillation among them. Methods The prevalence of atrial fibrillation was investigated among 201 patients referred for suspected obstructive sleep apnea. Patients without known atrial fibrillation were investigated with a standard 12-lead ECG at hospital and short intermittent handheld ECG recordings at home, during 14 days. Results Atrial fibrillation occurred in 13 of 201 subjects (6.5%), and in 12 of 61 men aged 60 years and older (20%). The prevalence of atrial fibrillation increased with sleep apnea severity (p = 0.038). All patients with atrial fibrillation were men and all had sleep apnea. Age 60 or older, the occurrence of central sleep apnea and diabetes mellitus were independent risk factors for atrial fibrillation after adjustments for body mass index, gender, sleep apnea and cardiovascular disease. Conclusions Atrial fibrillation is common among subjects referred for sleep apnea investigation and the prevalence of atrial fibrillation increases with sleep apnea severity. Independent risk factors for atrial fibrillation among patients investigated for suspected obstructive sleep apnea include the occurrence of coexisting central sleep apnea, age 60 years or older and diabetes mellitus. PMID:28178304

  12. Left atrial dysfunction detected by speckle tracking in patients with systemic sclerosis

    PubMed Central

    2014-01-01

    Background Cardiac involvement is a relevant clinical finding in systemic sclerosis (SSc) and is associated with poor prognosis. Left atrial (LA) remodeling and/or dysfunction can be an early sign of diastolic dysfunction. Two-dimensional speckle tracking echocardiography (STE) is a novel and promising tool for detecting very early changes in LA myocardial performance. Aim To assess whether STE strain parameters may detect early alterations in LA function in SSc patients. Methods Forty-two SSc patients (Group 1, age 50 ± 14 years, 95% females) without clinical evidence for cardiac involvement and 42 age- and gender-matched control subjects (Group 2, age 49 ± 13 years, 95% females) were evaluated with comprehensive 2D and Doppler echocardiography, including tissue Doppler imaging analysis. Positive peak left atrial longitudinal strain (ϵ pos peak), second positive left atrial longitudinal strain (sec ϵ pos peak), and negative left atrial longitudinal strain (ϵ neg peak) were measured using a 12-segment model for the LA, by commercially available semi-automated 2D speckle-tracking software (EchoPac PC version 108.1.4, GE Healthcare, Horten, Norway). Results All SSc patients had a normal left ventricular ejection fraction (63.1 ± 4%). SSc patients did not differ from controls in E/A (Group 1 = 1.1 ± 0.4 vs Group 2 = 1.3 ± 0.4, p = .14) or pulmonary arterial systolic pressure (Group 1 = 24.1 ± 8 mmHg vs Group 2 = 21 ± 7 mmHg, p = .17). SSc patients did not show significantly different indexed LA volumes (Group 1 = 24.9 ± 5.3 ml/m2 vs Group 2 = 24.7 ± 4.4 ml/m2, p = .8), whereas E/e’ ratio was significantly higher in SSc (Group 1 = 7.6 ± 2.4 vs Group 2 = 6.5 ± 1.7, p<0.05), although still within normal values. LA strain values were significantly different between the two groups (ϵ pos peak Group 1 = 31.3 ± 4.2% vs Group 2 = 35.0 ± 7.6%, p

  13. Surgical Ablation of Atrial Fibrillation during Mitral-Valve Surgery

    PubMed Central

    Gillinov, A. Marc; Gelijns, Annetine C.; Parides, Michael K.; DeRose, Joseph J.; Moskowitz, Alan J.; Voisine, Pierre; Ailawadi, Gorav; Bouchard, Denis; Smith, Peter K.; Mack, Michael J.; Acker, Michael A.; Mullen, John C.; Rose, Eric A.; Chang, Helena L.; Puskas, John D.; Couderc, Jean-Philippe; Gardner, Timothy J.; Varghese, Robin; Horvath, Keith A.; Bolling, Steven F.; Michler, Robert E.; Geller, Nancy L.; Ascheim, Deborah D.; Miller, Marissa A.; Bagiella, Emilia; Moquete, Ellen G.; Williams, Paula; Taddei-Peters, Wendy C.; O’Gara, Patrick T.; Blackstone, Eugene H.; Argenziano, Michael

    2015-01-01

    Background Among patients undergoing mitral-valve surgery, 30 to 50% present with atrial fibrillation, which is associated with reduced survival and increased risk of stroke. Surgical ablation of atrial fibrillation has been widely adopted, but evidence regarding its safety and effectiveness is limited. Methods We randomly assigned 260 patients with persistent or long-standing persistent atrial fibrillation who required mitral-valve surgery to undergo either surgical ablation (ablation group) or no ablation (control group) during the mitral-valve operation. Patients in the ablation group underwent further randomization to pulmonary-vein isolation or a biatrial maze procedure. All patients underwent closure of the left atrial appendage. The primary end point was freedom from atrial fibrillation at both 6 months and 12 months (as assessed by means of 3-day Holter monitoring). Results More patients in the ablation group than in the control group were free from atrial fibrillation at both 6 and 12 months (63.2% vs. 29.4%, P<0.001). There was no significant difference in the rate of freedom from atrial fibrillation between patients who underwent pulmonary-vein isolation and those who underwent the biatrial maze procedure (61.0% and 66.0%, respectively; P = 0.60). One-year mortality was 6.8% in the ablation group and 8.7% in the control group (hazard ratio with ablation, 0.76; 95% confidence interval, 0.32 to 1.84; P = 0.55). Ablation was associated with more implantations of a permanent pacemaker than was no ablation (21.5 vs. 8.1 per 100 patient-years, P = 0.01). There were no significant between-group differences in major cardiac or cerebrovascular adverse events, overall serious adverse events, or hospital readmissions. Conclusions The addition of atrial fibrillation ablation to mitral-valve surgery significantly increased the rate of freedom from atrial fibrillation at 1 year among patients with persistent or long-standing persistent atrial fibrillation, but the

  14. Cardiac systolic regional function and synchrony in endurance trained and untrained females

    PubMed Central

    Hedman, Kristofer; Tamás, Éva; Bjarnegård, Niclas; Brudin, Lars; Nylander, Eva

    2015-01-01

    Background Most studies on cardiac function in athletes describe overall heart function in predominately male participants. We aimed to compare segmental, regional and overall myocardial function and synchrony in female endurance athletes (ATH) and in age-matched sedentary females (CON). Methods In 46 ATH and 48 CON, echocardiography was used to measure peak longitudinal systolic strain and myocardial velocities in 12 left ventricular (LV) and 2 right ventricular (RV) segments. Regional and overall systolic function were calculated together with four indices of dyssynchrony. Results There were no differences in regional or overall LV systolic function between groups, or in any of the four dyssynchrony indices. Peak systolic velocity (s′) was higher in the RV of ATH than in CON (9.7±1.5 vs 8.7±1.5 cm/s, p=0.004), but not after indexing by cardiac length (p=0.331). Strain was similar in ATH and CON in 8 of 12 LV myocardial segments. In septum and anteroseptum, basal and mid-ventricular s′ was 6–7% and 17–19% higher in ATH than in CON (p<0.05), respectively, while s′ was 12% higher in CON in the basal LV lateral wall (p=0.013). After indexing by cardiac length, s′ was only higher in ATH in the mid-ventricular septum (p=0.041). Conclusions We found differences between trained and untrained females in segmental systolic myocardial function, but not in global measures of systolic function, including cardiac synchrony. These findings give new insights into cardiac adaptation to endurance training and could also be of use for sports cardiologists evaluating female athletes. PMID:27900120

  15. Cardiac dilatation and pump dysfunction without intrinsic myocardial systolic failure following chronic beta-adrenoreceptor activation.

    PubMed

    Osadchii, Oleg E; Norton, Gavin R; McKechnie, Richard; Deftereos, Dawn; Woodiwiss, Angela J

    2007-04-01

    There is no direct evidence to indicate that pump dysfunction in a dilated chamber reflects the impact of chamber dilatation rather than the degree of intrinsic systolic failure resulting from myocardial damage. In the present study, we explored the relative roles of intrinsic myocardial systolic dysfunction and chamber dilatation as mediators of left ventricular (LV) pump dysfunction. Administration of isoproterenol, a beta-adrenoreceptor agonist, for 3 mo to rats (0.1 mg.kg(-1).day(-1)) resulted in LV pump dysfunction as evidenced by a reduced LV endocardial fractional shortening (echocardiography) and a decrease in the slope of the LV systolic pressure-volume relation (isolated heart preparations). Although chronic beta-adrenoreceptor activation induced cardiomyocyte damage (deoxynucleotidyl transferase-mediated dUTP nick-end labeling) as well as beta(1)- and beta(2)-adrenoreceptor inotropic downregulation (attenuated contractile responses to dobutamine and salbutamol), these changes failed to translate into alterations in intrinsic myocardial contractility. Indeed, LV midwall fractional shortening (echocardiography) and the slope of the LV systolic stress-strain relation (isolated heart preparations) were unchanged. A normal intrinsic myocardial systolic function, despite the presence of cardiomyocyte damage and beta-adrenoreceptor inotropic downregulation, was ascribed to marked increases in myocardial norepinephrine release, to upregulation of alpha-adrenoreceptor-mediated contractile effects as determined by phenylephrine responsiveness, and to compensatory LV hypertrophy. LV pump failure was attributed to LV dilatation, as evidenced by increased LV internal dimensions (echocardiography), and a right shift and increased volume intercept of the LV diastolic pressure-volume relation. In conclusion, chronic sympathetic stimulation, despite reducing beta-adrenoreceptor-mediated inotropic responses and promoting myocyte apoptosis, may nevertheless induce pump

  16. Prognostic value of echocardiographic indicators of left ventricular systolic function in asymptomatic dialysis patients.

    PubMed

    Zoccali, Carmine; Benedetto, Francesco A; Mallamaci, Francesca; Tripepi, Giovanni; Giacone, Giuseppe; Cataliotti, Alessandro; Seminara, Giuseppe; Stancanelli, Benedetta; Malatino, Lorenzo S

    2004-04-01

    Patients with end-stage renal disease (ESRD) are at high risk for heart failure, but the prevalence and the prognostic value of asymptomatic systolic dysfunction in these patients are unknown. In this prospective cohort study, the authors have therefore assessed by echocardiography the prevalence and the prognostic value of systolic function as estimated by ejection fraction (EF), fractional shortening at endocardial level (endoFS), and at midwall (mwFS), in a cohort of 254 asymptomatic dialysis patients. Systolic dysfunction had a prevalence rate of 26% by endoFS and of 48% by mwFS. During the follow-up period, 125 patients had one or more fatal and nonfatal CV events. On multivariate COX regression analysis, the three LV systolic function indicators were independently associated with incident fatal and nonfatal CV events, and there were no differences in the predictive power of these indicators (P > 0.30). The prediction power of LV function indicators was largely independent of traditional and novel risk factors in ESRD such as C-reactive protein and asymmetric dimethyl arginine (ADMA). ADMA was significantly related with LV function indicators as well as with mortality and incident CV events, but these links were much reduced (P = NS) in models including LV function indicators. Of note, the risk of CV events was minimal in patients with normal LV mass and function, intermediate in patients with either LVH or systolic dysfunction, and maximal in patients displaying both alterations. The study of myocardial contractility by echocardiography provides prognostic information independently of LV mass and other risk factors in ESRD. Risk stratification by simple systolic function parameters may prove useful in secondary prevention strategies in these patients.

  17. Systematic review and meta-analysis of preterm birth and later systolic blood pressure.

    PubMed

    de Jong, Femke; Monuteaux, Michael C; van Elburg, Ruurd M; Gillman, Matthew W; Belfort, Mandy B

    2012-02-01

    Lower birth weight because of fetal growth restriction is associated with higher blood pressure later in life, but the extent to which preterm birth (<37 completed weeks' gestation) or very low birth weight (<1500 g) predicts higher blood pressure is less clear. We performed a systematic review of 27 observational studies that compared the resting or ambulatory systolic blood pressure or diagnosis of hypertension among children, adolescents, and adults born preterm or very low birth weight with those born at term. We performed a meta-analysis with the subset of 10 studies that reported the resting systolic blood pressure difference in millimeters of mercury with 95% CIs or SEs. We assessed methodologic quality with a modified Newcastle-Ottawa Scale. The 10 studies were composed of 1342 preterm or very low birth weight and 1738 term participants from 8 countries. The mean gestational age at birth of the preterm participants was 30.2 weeks (range: 28.8-34.1 weeks), birth weight was 1280 g (range: 1098-1958 g), and age at systolic blood pressure measurement was 17.8 years (range: 6.3-22.4 years). Former preterm or very low birth weight infants had higher systolic blood pressure than term infants (pooled estimate: 2.5 mm Hg [95% CI: 1.7-3.3 mm Hg]). For the 5 highest quality studies, the systolic blood pressure difference was slightly greater, at 3.8 mm Hg (95% CI: 2.6-5.0 mm Hg). We conclude that infants who are born preterm or very low birth weight have modestly higher systolic blood pressure later in life and may be at increased risk for developing hypertension and its sequelae.

  18. Circus movement atrial flutter in the canine sterile pericarditis model. Activation patterns during initiation, termination, and sustained reentry in vivo.

    PubMed

    Schoels, W; Gough, W B; Restivo, M; el-Sherif, N

    1990-07-01

    The mechanisms of single-loop reentry in a syncytium without anatomically predetermined pathways have not been shown. Using a "jacket electrode" with 111 bipolar electrodes in a nylon matrix, we mapped in situ the atrial epicardial surface during atrial flutter in dogs with sterile pericarditis. Of 21 episodes of reentrant atrial flutter, only four showed double-loop ("figure-eight") reentry, whereas in 17 episodes a single loop was present. During initiation of single-loop reentry, an arc of functional block extended to the atrioventricular (AV) ring. This forced activation to proceed as a single wave around the free end of the arc, before breaking through the arc close to the AV ring. Activation continued as one loop around an arc close to the AV ring (in eight episodes) or around a combined functional and anatomic obstacle (in nine episodes) when the arc joined an atrial vessel. A zone of slow conduction was consistently bordered by the arc of block and the AV ring or by the anatomic obstacle and the AV ring. Spontaneous termination occurred when conduction failed in this area and the arc rejoined the AV ring. High-density recordings (2 mm) along the arc of block showed double potentials separated by an isoelectric interval, interpreted as local activation and electrotonus due to activation on the opposite side of the arc. Histologically, a diffuse inflammatory reaction involved 50-80% of the atrial wall. A transitional layer of myocardial bundles with preserved cross striation, but separated by edema and inflammatory cells, was enclosed between an epicardial layer of fragmented myocytes and an endocardial layer of grossly intact myocardium. There were no distinctive features at sites of functional conduction block or slowed conduction. In conclusion, single-loop reentry is the common pattern during atrial flutter in this model. Its induction depends on an interaction of the AV ring, a functional arc of block, and a zone of slow conduction. The location of the

  19. Circuit for detecting initial systole and dicrotic notch. [for monitoring arterial pressure

    NASA Technical Reports Server (NTRS)

    Gebben, V. D.; Webb, J. A., Jr. (Inventor)

    1974-01-01

    Circuitry is disclosed for processing an arterial pressure waveform to produce during any one cycle a pulse corresponding to the initial systole and a pulse corresponding to the dicrotic notch. In a first channel, an electrical analog of the arterial pressure waveform is filtered and then compared to the original waveform to produce an initial systole signal. In a second channel, the analog is differentiated, filtered, and fed through a gate controlled by pulses from the first channel to produce an electrical pulse corresponding to the dicrotic notch.

  20. Constant-load versus heart rate-targeted exercise - Responses of systolic intervals

    NASA Technical Reports Server (NTRS)

    Lance, V. Q.; Spodick, D. H.

    1975-01-01

    Various systolic intervals were measured prior to and during heart rate-targeted bicycle ergometer exercise. There were striking similarities within each matched exercise set for Q-Im, isovolumetric contraction time, preejection period (PEP), and PEP/left ventricular ejection time (LVET). LVET was significantly shorter for rate-targeted exercise. It is concluded that either constant-load or rate-targeted bicycle ergometry may be used with the choice of method determined by the purpose of the protocol, and that systolic intervals (except LVET) should not be much altered owing to the method chosen.

  1. A new class of drugs for systolic heart failure: The PARADIGM-HF study.

    PubMed

    Sabe, Marwa A; Jacob, Miriam S; Taylor, David O

    2015-10-01

    The PARADIGM-HF trial (Prospective Comparison of ARNI With ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure) found a combination drug containing sacubitril (a neprilysin inhibitor) and valsartan (an angiotensin II receptor blocker) superior to enalapril (an angiotensin-converting enzyme inhibitor) in patients with systolic heart failure. Recently approved by the US Food and Drug Administration, sacubitril-valsartan is the first new drug in over a decade to decrease death rates in patients with systolic heart failure.

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

    PubMed

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

    2015-01-01

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

  3. Pulse transit time as a surrogate measure of changes in systolic arterial pressure in children during sleep.

    PubMed

    Vlahandonis, Anna; Biggs, Sarah N; Nixon, Gillian M; Davey, Margot J; Walter, Lisa M; Horne, Rosemary S C

    2014-08-01

    Pulse transit time has been proposed as a surrogate measure of systolic arterial pressure, as it is dependent upon arterial stiffness. Past research has shown that pulse transit time has a significant inverse relationship to systolic arterial pressure in adults; however, studies in children are limited. This study aimed to explore the relationship between systolic arterial pressure and pulse transit time in children during sleep. Twenty-five children (13.1 ± 1.6 years, 48% male) underwent overnight polysomnography (PSG) with a simultaneous recording of continuous systolic arterial pressure and photoplethysmography. Pulse transit time was calculated as the time delay between the R-wave peak of the electrocardiogram (ECG) to the 50% point of the upstroke of the corresponding photoplethysmography waveform; 500 beats of simultaneous systolic arterial pressure and pulse transit time were analysed in each sleep stage for each child. Pulse transit time was normalized to each subject's mean wake pulse transit time. The ability of pulse transit time to predict systolic arterial pressure change was determined by linear mixed-effects modelling. Significant negative correlations between pulse transit time and systolic arterial pressure were found for individual children for each sleep stage [mean correlations for cohort: non-rapid eye movement (NREM) sleep 1 and 2 r = -0.57, slow wave sleep (SWS) r = -0.76, REM r = -0.65, P < 0.01 for all]. Linear mixed-model analysis demonstrated that changes in pulse transit time were a significant predictor of changes in systolic arterial pressure for each sleep stage (P < 0.001). The model of pulse transit time-predicted systolic arterial pressure closely tracked actual systolic arterial pressure changes over time. This study demonstrated that pulse transit time was accurate in tracking systolic arterial pressure changes over time. Thus, the use of pulse transit time as a surrogate measure of changes in systolic arterial pressure in

  4. Functional mitral regurgitation: predictor for atrial substrate remodeling and poor ablation outcome in paroxysmal atrial fibrillation

    PubMed Central

    Qiao, Yu; Wu, Lingmin; Hou, Bingbo; Sun, Wei; Zheng, Lihui; Ding, Ligang; Chen, Gang; Zhang, Shu; Yao, Yan

    2016-01-01

    Abstract Functional mitral regurgitation (FMR) is not uncommon in atrial fibrillation (AF) patients. We sought to investigate the association between FMR and atrial substrate remodeling as well as the ablation outcome in paroxysmal AF (PAF) patients. We retrospectively analyzed a prospectively enrolled cohort of 132 patients (age 55.1 ± 9.6 years, 75.8% male) with symptomatic PAF who underwent initial ablation in our institute. Functional mitral regurgitation was defined as regurgitation jet area to left atrium (LA) area ratio ≥ 0.1 without any primary valvular disease. Voltage mapping of LA was performed under sinus rhythm. Low voltage zones (LVZs) were semi-quantitatively estimated and presented as low voltage index. Follow-up for AF recurrence ≥ 12 months was performed. In total, 40 patients (29.6%) were detected with FMR, who were older than the non-FMR patients (P = 0.007) and had larger LA diameters (P = 0.02). Left atrium LVZs were observed in 64.9% of patients with FMR versus 22.1% patients without FMR (P < 0.001). Functional mitral regurgitation independently predicted the presence of LVZs (OR 7.286; 95% CI 3.023–17.562; P < 0.001). During a mean follow-up of 22.9 ± 6.5 months, 38 patients (28.8%) experienced AF recurrence. The recurrence rate was 60.0% and 19.5% in FMR and non-FMR cohort, respectively (log rank P < 0.001). Multivariate analysis showed that FMR was an independent predictor for AF recurrence (HR 2.291; 95% CI 1.062–4.942; P = 0.03). Functional mitral regurgitation was strongly associated with atrial substrate remodeling. Furthermore, patients with FMR have substantial risk for AF recurrence post ablation. PMID:27472715

  5. Electrophysiologic basis of catheter ablation in atrial flutter.

    PubMed

    Touboul, P; Saoudi, N; Atallah, G; Kirkorian, G

    1989-12-05

    A reentrant mechanism is believed to be responsible for atrial flutter. The recent development of the entrainment criteria further supports this theory, and there is a general consensus that circus movement is the underlying abnormality that supports this arrhythmia. In most clinical studies, abnormal fragmented (or double spike) electrograms, suggesting the presence of areas of localized slowing of conduction or block, have been reported. They are almost always recorded in the lower and posterior portion of the right interatrial septum, but also frequently in the high lateral portion of the right atrium. The determination of their involvement in the reentry pathway is important for designing curative procedures such as surgery or ablation. The low atrial septal area surrounding the mouth of the coronary sinus was suspected as being the critical area of slow conduction in atrial flutter. Rapid pacing at that site can yield a surface electrocardiographic pattern similar to the clinically occurring arrhythmias. Additionally, the flutter circuit can be accelerated during atrial pacing at fixed and slightly faster rates than the intrinsic tachycardia rate--the so-called entrainment phenomenon. When entrainment criteria are fulfilled, tachycardia termination being by definition ruled out, any concomitant recorded local type II block identifies an area that must be outside the circuit. Such local block may be recorded either spontaneously or during entrainment and therefore helps in identifying atrial slow conduction areas that do not belong to the reentrant path. This approach was applied to identify the optimal ablation site in 8 patients with long-standing drug resistant atrial flutter. In 7 of 8 patients, we were able to identify a fragmented potential in the low posteroseptal area during sustained atrial flutter.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Atrial Fibrillation, Neurocognitive Decline and Gene Expression After Cardiopulmonary Bypass

    PubMed Central

    Dalal, Rahul S.; Sabe, Ashraf A.; Elmadhun, Nassrene Y.; Ramlawi, Basel; Sellke, Frank W.

    2015-01-01

    OBJECTIVE Atrial fibrillation and neurocognitive decline are common complications after cardiopulmonary bypass. By utilizing genomic microarrays we investigate whether gene expression is associated with postoperative atrial fibrillation and neurocognitive decline. METHODS Twenty one cardiac surgery patients were prospectively matched and underwent neurocognitive assessments pre-operatively and four days postoperatively. The whole blood collected in the pre-cardiopulmonary bypass, 6 hours after-cardiopulmonary bypass, and on the 4th postoperative day was hybridized to Affymetrix Gene Chip U133 Plus 2.0 Microarrays. Gene expression in patients who developed postoperative atrial fibrillation and neurocognitive decline (n=6; POAF+NCD) was compared with gene expression in patients with postoperative atrial fibrillation and normal cognitive function (n=5; POAF+NORM) and patients with sinus rhythm and normal cognitive function (n=10; SR+NORM). Regulated genes were identified using JMP Genomics 4.0 with a false discovery rate of 0.05 and fold change of >1.5 or <-1.5. RESULTS Eleven patients developed postoperative atrial fibrillation. Six of these also developed neurocognitive decline. Of the 12 patients with sinus rhythm, only 2 developed neurocognitive decline. POAF+NCD patients had unique regulation of 17 named genes preoperatively, 60 named genes six hours after cardiopulmonary bypass, and 34 named genes four days postoperatively (P<0.05) compared with normal patients. Pathway analysis demonstrated that these genes are involved in cell death, inflammation, cardiac remodeling and nervous system function. CONCLUSION Patients who developed postoperative atrial fibrillation and neurocognitive decline after cardiopulmonary bypass may have differential genomic responses compared to normal patients and patients with only postoperative atrial fibrillation, suggesting common pathophysiology for these conditions. Further exploration of these genes may provide insight into the

  7. Reduced kidney function is a risk factor for atrial fibrillation.

    PubMed

    Laukkanen, Jari A; Zaccardi, Francesco; Karppi, Jouni; Ronkainen, Kimmo; Kurl, Sudhir

    2016-08-01

    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 < 0.001) in subjects with reduced kidney function (eGFRcys , 15-59 mL/min per 1.73 m(2) ) compared to subjects with normal kidney function (≥90 mL/min per 1.73 m(2) ). Similar results were also found when comparing the respective groups of subjects defined by their eGRFcreat levels (hazard ratio 2.41, CI 1.09-5.30, P = 0.029). Consistently, subjects with ACR ≥300 mg/g had an increased risk of incident atrial fibrillation (hazard ratio 2.16, CI 1.35-2.82, P < 0.001) compared to those with ACR <30 mg/g. Reduced eGFR and albuminuria were associated with an increased risk of atrial fibrillation.

  8. Stroke prevention in atrial fibrillation: pharmacological rate versus rhythm control.

    PubMed

    Sherman, David G

    2007-02-01

    Atrial fibrillation is a common arrhythmia associated with increased risk for embolic stroke. Restoration of sinus rhythm in patients with atrial fibrillation is a logical strategy to prevent the cardiovascular and thromboembolic complications of this dysrhythmia. The most common strategy for restoration of sinus rhythm is pharmacological antiarrhythmic therapy with or without electrical cardioversion. Five randomized clinical trials compared rhythm to rate-control strategies in patients with atrial fibrillation. These trials examined mortality, thromboembolic complications, exercise tolerance, quality of life, hospital admissions and drug-related adverse reactions. Mortality ranged from 2.9% to 23.8% among the trial subjects randomized to rhythm control versus 1.0% to 21.3% in the rate control subjects. The risk of thromboemboli was greater: 2.9% to 7.9% in the rhythm-control subjects compared with 0% to 5.5% in the rate control subjects. Hospital admissions and drug-related adverse events were increased in the rhythm-control subjects. Stroke and systemic emboli occurred more often in the rhythm-control subjects many of whom had been withdrawn from anticoagulation. Rhythm-control offered no advantage compared with rate control for patients with atrial fibrillation at increased risk for stroke. One explanation for this finding is that those patients thought to have been successfully converted to sinus rhythm in fact had asymptomatic paroxysmal episodes of atrial fibrillation increasing their risk of stroke because they were unprotected by anticoagulation. Pharmacological attempts to restore atrial fibrillation to sinus rhythm do not improve mortality or reduce thromboembolic events. All patients with atrial fibrillation at increased risk for stroke should be continued on long-term anticoagulation even if they appear to have been successfully restored to sinus rhythm.

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

    PubMed

    Amasyali, Basri; Kilic, Ayhan

    2015-06-01

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

  10. Prediction of early-onset atrial tachyarrhythmia after successful trans-catheter device closure of atrial septal defect

    PubMed Central

    Park, Kyoung-Min; Hwang, Jin Kyung; Chun, Kwang Jin; Park, Seung-Jung; On, Young Keun; Kim, June Soo; Park, Seung Woo; Kang, I-Seok; Song, Jinyoung; Huh, June

    2016-01-01

    Abstract Atrial tachyarrhythmia is a well-known long-term complication of atrial septal defect (ASD) in adults, even after successful trans-catheter closure. However, the risk factors for early-onset atrial tachyarrhythmia after trans-catheter closure remain unclear. This retrospective study enrolled adults with secundum ASD undergoing trans-catheter closure from January 2000 to March 2014. We analyzed the clinical characteristics of patients and assessed risk factors for new-onset atrial tachyarrhythmia defined as a composite of atrial fibrillation or flutter (AF/AFL) after ASD closure. We enrolled a total of 427 patients; 123 were male (28.8%) and the median age was 37.0 (interquartile range [IQR]: 18.3–49.0). Nineteen (4.4%) patients had documented atrial tachyarrhythmia during the follow-up period (median: 11.4 months [IQR: 5.4–24]). Patients with transient AF/AFL during closure showed a greater incidence of new-onset atrial tachyarrhythmia during the follow-up period than patients with consistent sinus rhythm during closure (27.3% vs 3.8%; P = 0.01). Most new-onset atrial tachyarrhythmias were documented within 6 months (median: 2.6 [IQR: 1.2–4.1] months) of closure. In the multivariate analysis, the risk for new-onset atrial tachyarrhythmia was significant in patients with AF/AFL during closure (hazard ratio [HR]: 9.90, 95% confidence interval [CI]: 2.86–34.20; P < 0.001), deficient posteroinferior rim (HR: 5.48, 95% CI: 1.15–25.72; P = 0.04), and age of closure over 48 years (HR: 3.30, 95% CI: 1.30–8.38; P = 0.01). In conclusion, transient AF/AFL during trans-catheter closure of ASD as well as deficient posteroinferior rim and age of closure over 48 years may be useful for predicting early new-onset atrial tachyarrhythmia after device closure. PMID:27583905

  11. Delayed Left Atrial Perforation Associated with Erosion After Device Closure of an Atrial Septal Defect

    PubMed Central

    Kim, Ji Seong; Yeom, Sang Yoon; Kim, Sue Hyun; Choi, Jae Woong; Kim, Kyung Hwan

    2017-01-01

    A 43-year-old man who had had a history of atrial septal defect (ASD) device closure 31 months previously presented with abrupt chest and back pain along with progressive cardiogenic shock and cardiac arrest. After resuscitation, he was diagnosed with cardiac tamponade. Diagnostic and therapeutic surgical exploration revealed left atrium (LA) perforation due to LA roof erosion from a deficient aortic rim. Device removal, primary repair of the LA perforation site, and ASD patch closure were performed successfully. The postoperative course was uneventful. The patient was discharged after 6 weeks of empirical antibiotic therapy without any other significant complications. PMID:28382270

  12. Mechanisms and clinical significance of early recurrences of atrial arrhythmias after catheter ablation for atrial fibrillation

    PubMed Central

    Liang, Jackson J; Dixit, Sanjay; Santangeli, Pasquale

    2016-01-01

    Early recurrence of atrial arrhythmias (ERAA) after ablation is common and strongly predicts late recurrences and ablation failure. However, since arrhythmia may eventually resolve in up to half of patients with ERAA, guidelines do not recommend immediate reintervention for ERAA episodes occurring during a 3-mo post-ablation blanking period. Certain clinical demographic, electrophysiologic, procedural, and ERAA-related characteristics may predict a higher likelihood of long-term ablation failure. In this review, we aim to discuss potential mechanisms of ERAA, and to summarize the clinical significance, prognostic implications, and treatment options for ERAA. PMID:27957250

  13. Voltage-activated sodium current is inhibited by capsaicin in rat atrial myocytes.

    PubMed

    Milesi, V; Rebolledo, A; Alvis, A G; Raingo, J; Grassi de Gende, A O

    2001-04-13

    The effects of capsaicin, the active principle of hot pepper genus Capsicum, were studied on voltage-activated, tetrodotoxin-sensitive Na+ currents in isolated rat atrial cells using the patch clamp technique in the whole-cell configuration. 0.4 and 4 microM of capsaicin produced a significant tonic block on voltage-activated Na+ current (I(Na)) evoked by a depolarizing step to -40 mV from a holding potential of -100 mV (49 +/- 7% n = 11, P < 0.05 and 72 +/- 13% n = 4, P < 0.05 respectively). We didn't observe any use-dependent block of capsaicin in our experimental conditions. Capsaicin slowed the time decay of inactivation of I(Na), and increased the time constant of the recovery of inactivation. Capsaicin and tetrodotoxin (TTX) depressed contractility of isolated electrically driven left rat atria, being the depression of maximal velocity of force development (dF/dt(max)) with respect to control values of 19 +/- 3% at 1 microM of capsaicin and 22 +/- 2% at 1 microM of TTX. These results show an inhibitory effect of capsaicin on I(Na) in isolated atrial cells that may modify the electrical and contractile function of the rat heart.

  14. R4496C RyR2 mutation impairs atrial and ventricular contractility

    PubMed Central

    Coppini, Raffaele; Scellini, Beatrice; Ferrara, Claudia; Pioner, Josè Manuel; Mazzoni, Luca; Priori, Silvia; Cerbai, Elisabetta; Tesi, Chiara; Poggesi, Corrado

    2016-01-01

    Ryanodine receptor (RyR2) is the major Ca2+ channel of the cardiac sarcoplasmic reticulum (SR) and plays a crucial role in the generation of myocardial force. Changes in RyR2 gating properties and resulting increases in its open probability (Po) are associated with Ca2+ leakage from the SR and arrhythmias; however, the effects of RyR2 dysfunction on myocardial contractility are unknown. Here, we investigated the possibility that a RyR2 mutation associated with catecholaminergic polymorphic ventricular tachycardia, R4496C, affects the contractile function of atrial and ventricular myocardium. We measured isometric twitch tension in left ventricular and atrial trabeculae from wild-type mice and heterozygous transgenic mice carrying the R4496C RyR2 mutation and found that twitch force was comparable under baseline conditions (30°C, 2 mM [Ca2+]o, 1 Hz). However, the positive inotropic responses to high stimulation frequency, 0.1 µM isoproterenol, and 5 mM [Ca2+]o were decreased in R4496C trabeculae, as was post-rest potentiation. We investigated the mechanisms underlying inotropic insufficiency in R4496C muscles in single ventricular myocytes. Under baseline conditions, the amplitude of the Ca2+ transient was normal, despite the reduced SR Ca2+ content. Under inotropic challenge, however, R4496C myocytes were unable to boost the amplitude of Ca2+ transients because they are incapable of properly increasing the amount of Ca2+ stored in the SR because of a larger SR Ca2+ leakage. Recovery of force in response to premature stimuli was faster in R4496C myocardium, despite the unchanged rates of recovery of L-type Ca2+ channel current (ICa-L) and SR Ca2+ content in single myocytes. A faster recovery from inactivation of the mutant R4496C channels could explain this behavior. In conclusion, changes in RyR2 channel gating associated with the R4496C mutation could be directly responsible for the alterations in both ventricular and atrial contractility. The increased RyR2 Po

  15. Percutaneous closure of a left atrial appendage with relevant suture dehiscence.

    PubMed

    Kleinebrecht, L; Veulemans, V; Polzin, A; Kelm, M; Zeus, T

    2017-02-01

    Atrial fibrillation is a widespread disease and highly relevant as it carries an extended risk for ischaemic stroke. Surgical closure of the left atrial appendage is routinely performed during open heart surgery in patients with atrial fibrillation with the aim of thromboembolic protection. In this report we present a successful percutaneous closure of a left atrial appendage, which showed clinically relevant suture dehiscence several years after surgical closure.

  16. Effect of Substrate Modification in Catheter Ablation of Paroxysmal Atrial Fibrillation

    PubMed Central

    Nam, Gi-Byoung; Jin, Eun-Sun; Choi, HyungOh; Song, Hae-Geun; Kim, Sung-Hwan; Kim, Ki-Hun; Hwang, Eui-Seock; Park, Kyoung-Min; Kim, Jun; Rhee, Kyoung-Suk; Choi, Kee-Joon; Kim, You-Ho

    2012-01-01

    Catheter ablation of atrial fibrillation that targets complex fractionated electrogram sites has been widely applied in the management of persistent atrial fibrillation. The clinical outcomes of pulmonary vein isolation alone and pulmonary vein isolation plus the use of complex fractionated electrogram-guided ablation (CFEA) have not been fully compared in patients with paroxysmal atrial fibrillation. This prospective study included 70 patients with symptomatic paroxysmal atrial fibrillation that remained inducible after pulmonary vein isolation. For radio-frequency catheter ablation, patients were nonrandomly assigned to a control group (pulmonary vein isolation alone, Group 1, n=35) or a CFEA group (pulmonary vein isolation plus additional CFEA, Group 2, n=35). The times to first recurrence of atrial tachyarrhythmias were compared between the 2 groups. In Group 2, CFEA rendered atrial fibrillation noninducible in 16 patients (45.7%) and converted inducible atrial fibrillation into inducible atrial flutters in 12 patients (34.3%). Atrial fibrillation remained inducible in 7 patients (20%) after the combined ablation procedures. After a mean follow-up of 23 months, freedom from recurrence of atrial tachyarrhythmias was significantly higher in Group 2 than in Group 1 (P=0.037). In Group 1, all of the recurrent tachyarrhythmias were atrial fibrillation, whereas regular tachycardia was the major mechanism of recurrent arrhythmias in Group 2 (atrial tachycardia or atrial flutter in 5 of 6 patients and atrial fibrillation in 1 patient). We found that CFEA after pulmonary vein isolation significantly reduced recurrent atrial tachyarrhythmia and might modify the pattern of arrhythmia recurrence in patients with paroxysmal atrial fibrillation. PMID:22719147

  17. Identifying Future Research Priorities Using Value of Information Analyses: Left Atrial Appendage Occlusion Devices in Atrial Fibrillation

    PubMed Central

    Micieli, Andrew; Bennell, Maria C.; Pham, Ba’; Krahn, Murray; Singh, Sheldon M.; Wijeysundera, Harindra C.

    2014-01-01

    Background Left atrial appendage occlusion devices are cost effective for stroke prophylaxis in atrial fibrillation when compared with dabigatran or warfarin. We illustrate the use of value‐of‐information analyses to quantify the degree and consequences of decisional uncertainty and to identify future research priorities. Methods and Results A microsimulation decision‐analytic model compared left atrial appendage occlusion devices to dabigatran or warfarin in atrial fibrillation. Probabilistic sensitivity analysis quantified the degree of parameter uncertainty. Expected value of perfect information analyses showed the consequences of this uncertainty. Expected value of partial perfect information analyses were done on sets of input parameters (cost, utilities, and probabilities) to identify the source of the greatest uncertainty. One‐way sensitivity analyses identified individual parameters for expected value of partial perfect information analyses. Population expected value of perfect information and expected value of partial perfect information provided an upper bound on the cost of future research. Substantial uncertainty was identified, with left atrial appendage occlusion devices being preferred in only 47% of simulations. The expected value of perfect information was $8542 per patient and $227.3 million at a population level. The expected value of partial perfect information for the set of probability parameters represented the most important source of uncertainty, at $6875. Identified in 1‐way sensitivity analyses, the expected value of partial perfect information for the odds ratio for stroke with left atrial appendage occlusion compared with warfarin was calculated at $7312 per patient or $194.5 million at a population level. Conclusion The relative efficacy of stroke reduction with left atrial appendage occlusion devices in relation to warfarin is an important source of uncertainty. Improving estimates of this parameter should be the priority

  18. Huge right atrial myxoma causing fixed tricuspid stenosis with constitutional symptoms.

    PubMed

    Kuralay, Erkan; Cingöz, Faruk; Günay, Celalettin; Demirkiliç, Ufuk; Tatar, Harun

    2003-01-01

    Nonspecific constitutional symptoms are reported mostly in patients with left-atrial myxomas, which occur five times as often as its right-atrial counterpart. We present huge right-atrial myxoma, which obstructs tricuspid orifice with nonspecific constitutional symptoms without any pulmonary embolism attack.

  19. Detection of atrial arrhythmia for cardiac rhythm management by implantable devices.

    PubMed

    Morris, M M; KenKnight, B H; Lang, D J

    2000-01-01

    Implantable atrial defibrillators (IAD) should provide pacing therapy whenever appropriate (ie, typical atrial flutter) to minimize shock-related patient discomfort. Additionally, IADs should provide diagnostics regarding atrial arrhythmia type and frequency of occurrence to enable improved physician management of atrial arrhythmia. To achieve this, IADs should accurately classify atrial arrhythmia such as atrial fibrillation (AF) and atrial flutter (AFL) This article evaluates the performance of an algorithm, atrial rhythm classification (ARC), designed to classify AF and AFL. The ARC algorithm uses maximum rate, standard deviation, and range of the 12 most recent atrial cycle lengths to plot a point in a three-dimensional space. A decision boundary divides the space into 2 regions--faster/unstable atrial cycle lengths (AF) or slower/stable cycle lengths (AFL). Classifications are made on a sliding window of 12 consecutive cycles until the end of the episode is reached. In this way, continuous episode feedback is provided that can be used to help guide device therapy, measure arrhythmia type and frequency of occurrence. Bipolar (1-cm) electrogram episodes of AF (n = 16) and AFL (n = 7) were acquired from 20 patients and retrospectively analyzed using the ARC algorithm. The sensitivity and specificity in this study was 0.993 and 0.982, respectively. The ARC algorithm would have appropriately guided atrial therapy and minimized discomfort associated with defibrillation shocks in this small patient data set warranting further studies. The ARC algorithm may also be beneficial as a diagnostic tool to assist physician management of atrial arrhythmia.

  20. Isolated right atrial compression as a late sequela of aortic valve replacement.

    PubMed Central

    Grishkin, B A; Catalano, P W; Watts, M A

    1994-01-01

    Isolated right atrial compression occurred 31 months after aortic valve replacement. Aortic bleeding contained by adjacent pericardium produced a pseudoaneurysm and local atrial tamponade. Transthoracic echocardiography could not distinguish the extracardiac hematoma from an intra-atrial thrombus, temporarily misleading investigators. Images PMID:8000271

  1. Systolically gated 3D phase contrast MRA of mesenteric arteries in suspected mesenteric ischemia

    SciTech Connect

    Wasser, M.N.; Schultze Kool, L.J.; Roos, A. de

    1996-03-01

    Our goal was to assess the value of MRA for detecting stenoses in the celiac (CA) and superior mesenteric (SMA) arteries in patients suspected of having chronic mesenteric ischemia, using an optimized systolically gated 3D phase contrast technique. In an initial study in 24 patients who underwent conventional angiography of the abdominal vessels for different clinical indications, a 3D phase contrast MRA technique (3D-PCA) was evaluated and optimized to image the CAs and SMAs. Subsequently, a prospective study was performed to assess the value of systolically gated 3D-PCA in evaluation of the mesenteric arteries in 10 patients with signs and symptoms of chronic mesenteric ischemia. Intraarterial digital subtraction angiography and surgical findings were used as the reference standard. In the initial study, systolic gating appeared to be essential in imaging the SMA on 3D-PCA. In 10 patients suspected of mesenteric ischemia, systolically gated 3D-PCA identified significant proximal disease in the two mesenteric vessels in 4 patients. These patients underwent successful reconstruction of their stenotic vessels. Cardiac-gated MRA may become a useful tool in selection of patients suspected of having mesenteric ischemia who may benefit from surgery. 16 refs., 6 figs., 4 tabs.

  2. Joint Symbolic Dynamics Analysis of Heart Rate and Systolic Blood Pressure Interactions in Dilated Cardiomyopathy

    DTIC Science & Technology

    2007-11-02

    Abstract- The dilated cardiomyopathy (DCM) induces important changes in the autonomic control. Measures of heart rate (HR) variability and systolic...rather simple physiological interpretations and seems to be particularly suitable for risk stratification in patients with dilated cardiomyopathy ...Keywords - Symbolic dynamics, heart rate variability, blood pressure variability I. INTRODUCTION Patients suffering from dilated cardiomyopathy

  3. Assessment of right ventricular systolic function by echocardiography after surgical repair of congenital heart defects.

    PubMed

    Khraiche, Diala; Ben Moussa, Nidhal

    2016-02-01

    Postoperative impairment of right ventricular (RV) systolic function can appear after surgical repair of complex congenital heart defects, such as tetralogy of Fallot; it is caused by chronic volume and/or pressure overload due to pulmonary regurgitation and/or stenosis. RV dysfunction is strongly associated with prognosis in these patients. Cardiac magnetic resonance imaging is the gold standard for quantification of RV volumes and ejection fraction in patients with congenital heart diseases; however, it is costly and is not widely available. Echocardiography is the imaging modality that is most available and most frequently used to assess RV systolic function. However, RV ejection fraction cannot be measured accurately by standard two-dimensional echocardiography because of its pyramidal shape. Surrogate parameters of RV systolic function are mostly used in routine practice. New techniques of two-dimensional strain and three-dimensional quantification of RV volumes and ejection fraction have been developed in recent years. The aim of this article is to show the pertinence of each variable of RV systolic function measured by echocardiography in patients with repaired congenital heart disease and residual chronic RV overload.

  4. Estimation of central systolic blood pressure using an oscillometric blood pressure monitor.

    PubMed

    Cheng, Hao-Min; Wang, Kang-Ling; Chen, Ying-Hwa; Lin, Shing-Jong; Chen, Lung-Ching; Sung, Shih-Hsien; Ding, Philip Yu-An; Yu, Wen-Chung; Chen, Jaw-Wen; Chen, Chen-Huan

    2010-06-01

    Current noninvasive techniques for assessing central aortic pressure require the recording of an arterial pressure wave using a high-fidelity applanation tonometer. We therefore developed and validated a novel method to estimate the central aortic systolic pressure using an oscillometric blood pressure monitor alone. Invasive high-fidelity right brachial and central aortic pressure waves, and left-brachial pulse volume plethysmography from an oscillometric blood pressure monitor, were obtained at baseline and 3 min after administration of sublingual nitroglycerin in 100 patients during cardiac catheterization. In the initial 50 patients (Generation Group), Central systolic blood pressure was predicted by a multi-variate prediction model generated from the comprehensive analysis of the invasive brachial pressure wave, including brachial late-systolic shoulder pressure value and parameters related to wave reflection and arterial compliance. Another prediction model was similarly constructed from the noninvasively calibrated pulse volume plethysmography. Both models were validated in the subsequent 50 patients (Validation Group) with results: r=0.98 (P<0.001) and mean difference=0.5+/-4.5 (95% confidence interval -8.3 to 9.3) mm Hg for the invasive model, and r=0.93 (P<0.001) and mean difference=-0.1+/-7.6 (95% confidence interval -15.0 to 14.8) mm Hg for the noninvasive model. Thus, our results indicate that central aortic systolic blood pressure could be estimated by analysis of the noninvasive brachial pressure wave alone from an oscillometric blood pressure monitor.

  5. Linkage analysis of systolic blood pressure: a score statistic and computer implementation

    PubMed Central

    Wang, Kai; Peng, Yingwei

    2003-01-01

    A genome-wide linkage analysis was conducted on systolic blood pressure using a score statistic. The randomly selected Replicate 34 of the simulated data was used. The score statistic was applied to the sibships derived from the general pedigrees. An add-on R program to GENEHUNTER was developed for this analysis and is freely available. PMID:14975145

  6. Relationship between systolic time intervals and heart rate during four circulatory stress tests.

    PubMed

    Mäntysaari, M; Antila, K; Peltonen, T

    1984-01-01

    The linear regression equations between heart rate and systolic time intervals were calculated before and during a handgrip test, an orthostatic test, the Valsalva test and a cold pressor test. The subjects were 30 healthy men, average age 20 years. During the 1st min of orthostasis the regression line of the left ventricular ejection time (LVET) was significantly (P less than 0.05) steeper than at rest and that of the pre-ejection period (PEP) was significantly (P less than 0.01) less steep than at rest, and the regression between HR and the PEP/LVET ratio deviated significantly (P less than 0.001) from zero. During the Valsalva maneuver, the regression line of the LVET became significantly (P less than 0.001) steeper than at rest and the regression coefficient of the PEP changed from negative to positive, the difference being significant (P less than 0.001); the regression between HR and the PEP/LVET also deviated significantly (P less than 0.001) from zero. During the cold pressor test the regression line of the electromechanic systole (Q-S2 time) was significantly (P less than 0.01) less steep than at rest. It was concluded that the use of regression equations calculated for the systolic time intervals and heart rate at rest can lead to errors when applied to rate correction of systolic time intervals during an orthostatic, Valsalva, or a cold pressor test.

  7. Management of refractory atrial fibrillation post surgical ablation

    PubMed Central

    Altman, Robert K.; Proietti, Riccardo; Barrett, Conor D.; Paoletti Perini, Alessandro; Santangeli, Pasquale; Danik, Stephan B.; Di Biase, Luigi

    2014-01-01

    Over the past two decades, invasive techniques to treat atrial fibrillation (AF) including catheter-based and surgical procedures have evolved along with our understanding of the pathophysiology of this arrhythmia. Surgical treatment of AF may be performed on patients undergoing cardiac surgery for other reasons (concomitant surgical ablation) or as a stand-alone procedure. Advances in technology and technique have made surgical intervention for AF more widespread. Despite improvements in outcome of both catheter-based and surgical treatment for AF, recurrence of atrial arrhythmias following initial invasive therapy may occur.Atrial arrhythmias may occur early or late in the post-operative course after surgical ablation. Early arrhythmias are generally treated with prompt electrical cardioversion with or without antiarrhythmic therapy and do not necessarily represent treatment failure. The mechanism of persistent or late occurring atrial arrhythmias is complex, and these arrhythmias may be resistant to antiarrhythmic drug therapy. The characterization and management of recurrent atrial arrhythmias following surgical ablation of AF are discussed below. PMID:24516805

  8. Left atrial strain after maximal exercise in competitive waterpolo players.

    PubMed

    Santoro, Amato; Alvino, Federico; Antonelli, Giovanni; Molle, Roberta; Mondillo, Sergio

    2016-03-01

    Left atrial (LA) function is a determinant of left ventricular (LV) filling. It carries out three main functions: reservoir, conduit, contractile. Aim of this study was to evaluate the role of LA and its deformation properties on LV filling at rest (R) and immediately after a maximal exercise (ME) through the speckle tracking echocardiography. Population enrolled was composed by 23 water polo athletes who performed a ME of six repeats of 100 m freestyle swim sets. At ME peak atrial longitudinal strain was reduced but all strain rate (SR) parameters increased, respectively positive peak SR at reservoir phase, SR negative peak at rapid ventricular filling (SRep) and SR negative peak at late ventricular filling (SRlp), that corresponds to atrial contraction phase. We showed a parallel increase in E and A pulsed Doppler wave and SRep and SRlp; particularly at ME, A wave and SRlp increased more respectively than E wave and SRep. SRlp was related to ejection fraction (EF) (r = -0.47; p < 0.01). At multivariate analysis SRlp was an independent predictor of EF (β: -0.47; p = 0.016). The increased sympathetic tone results into increased late diastolic LV filling with augmented atrial contractility and a decrease in diastolic filling time. During exercise LV filling was probably optimized by an enhanced and rapid LA conduit phase and by a vigorous atrial contraction during late LV filling.

  9. Clinical implications of the P wave duration and dispersion: relationship between atrial conduction defects and abnormally prolonged and fractionated atrial endocardial electrograms.

    PubMed

    Centurión, Osmar Antonio

    2009-05-01

    Atrial conduction disease provides a suitable substrate for reentry and appears to be a major predisposing factor for the development of atrial fibrillation. It was demonstrated that when depressed conduction was observed in recordings from human atrial muscle, the ultra-structure was usually abnormal. Areas of poorly coupled fibers in diseased atrial tissue with progressive fibro-degenerative changes may lead to abnormal electrophysiological characteristics. Structural inhomogeneity or local differences in electrophysiological or ultra-structural properties are considered to play a major role in the initiation of reentrant circuits due to the increased likelihood of unidirectional block of the premature impulse. The P wave of the electrocardiogram may show alterations that can be associated with atrial arrhythmias. It was shown that there is a statistical association between the low resting membrane potential and a prolonged P wave duration. Also a prolonged inter-atrial conduction time was significantly related to abnormal P wave morphology. In the evaluation of patients with altered P waves in the electrocardiogram, it is very important to keep in mind that, patients who have a great susceptibility to develop AF possess abnormally prolonged and fractionated atrial endocardial electrograms in sinus rhythm within the right atrium, a significantly longer P wave duration, a significantly longer intra-atrial and inter-atrial conduction time of sinus impulses; and a significantly greater sinus node dysfunction and higher incidence of induction of sustained atrial fibrillation. Awareness of this strong association may lead to a better therapeutic management in individual patients.

  10. Dairy consumption, systolic blood pressure, and risk of hypertension: Mendelian randomization study.

    PubMed

    Ding, Ming; Huang, Tao; Bergholdt, Helle Km; Nordestgaard, Børge G; Ellervik, Christina; Qi, Lu

    2017-03-16

    Objective To examine whether previous observed inverse associations of dairy intake with systolic blood pressure and risk of hypertension were causal.Design Mendelian randomization study using the single nucleotide polymorphism rs4988235 related to lactase persistence as an instrumental variable.Setting CHARGE (Cohorts for Heart and Aging Research in Genomic Epidemiology) Consortium.Participants Data from 22 studies with 171 213 participants, and an additional 10 published prospective studies with 26 119 participants included in the observational analysis.Main outcome measures The instrumental variable estimation was conducted using the ratio of coefficients approach. Using meta-analysis, an additional eight published randomized clinical trials on the association of dairy consumption with systolic blood pressure were summarized.Results Compared with the CC genotype (CC is associated with complete lactase deficiency), the CT/TT genotype (TT is associated with lactose persistence, and CT is associated with certain lactase deficiency) of LCT-13910 (lactase persistence gene) rs4988235 was associated with higher dairy consumption (0.23 (about 55 g/day), 95% confidence interval 0.17 to 0.29) serving/day; P<0.001) and was not associated with systolic blood pressure (0.31, 95% confidence interval -0.05 to 0.68 mm Hg; P=0.09) or risk of hypertension (odds ratio 1.01, 95% confidence interval 0.97 to 1.05; P=0.27). Using LCT-13910 rs4988235 as the instrumental variable, genetically determined dairy consumption was not associated with systolic blood pressure (β=1.35, 95% confidence interval -0.28 to 2.97 mm Hg for each serving/day) or risk of hypertension (odds ratio 1.04, 0.88 to 1.24). Moreover, meta-analysis of the published clinical trials showed that higher dairy intake has no significant effect on change in systolic blood pressure for interventions over one month to 12 months (intervention compared with control groups: β=-0.21, 95% confidence interval -0

  11. Atrial natriuretic factor increases vascular permeability

    SciTech Connect

    Lockette, W.; Brennaman, B. )

    1990-12-01

    An increase in central blood volume in microgravity may result in increased plasma levels of atrial natriuretic factor (ANF). Since elevations in plasma ANF are found in clinical syndromes associated with edema, and since space motion sickness induced by microgravity is associated with an increase in central blood volume and facial edema, we determined whether ANF increases capillary permeability to plasma protein. Conscious, bilaterally nephrectomized male rats were infused with either saline, ANF + saline, or hexamethonium + saline over 2 h following bolus injections of 125I-albumin and 14C-dextran of similar molecular size. Blood pressure was monitored and serial determinations of hematocrits were made. Animals infused with 1.0 micrograms.kg-1.min-1 ANF had significantly higher hematocrits than animals infused with saline vehicle. Infusion of ANF increased the extravasation of 125I-albumin, but not 14C-dextran from the intravascular compartment. ANF also induced a depressor response in rats, but the change in blood pressure did not account for changes in capillary permeability to albumin; similar depressor responses induced by hexamethonium were not accompanied by increased extravasation of albumin from the intravascular compartment. ANF may decrease plasma volume by increasing permeability to albumin, and this effect of ANF may account for some of the signs and symptoms of space motion sickness.

  12. [New oral anticoagulants in atrial fibrillation].

    PubMed

    Veltkamp, R; Hacke, W

    2011-02-01

    Atrial fibrillation (AF) causes at least 20% of all ischemic strokes. In large randomized trials of primary and secondary stroke prevention, anticoagulation with vitamin K antagonists (VKA) protected much more efficiently than antiplatelet agents against stroke. Because of the problematic pharmacological properties of VKA only part of the AF patients are currently being treated with oral anticoagulants (OAK). The targeted development of specific oral inhibitors of the central coagulation factors thrombin and factor Xa allows reliable anticoagulation without regular coagulation monitoring. In the present review, pharmacological properties of the different agents are compared. Of the four large randomized phase 3 studies in AF (RELY, ROCKET-AF, ARISTOTLE, ENGAGE-AF) with the primary efficacy endpoint stroke and systemic embolism, the published data from the RELY trial indicate a superior efficacy of dabigatran etexilate (2 × 150 mg/day) and a lower risk of intracranial hemorrhage compared to warfarin. Favorable preliminary results have been demonstrated for the factor Xa inhibitor rivaroxaban. Apixaban was more efficacious than ASA and had a similar risk of hemorrhage in the AVERROES study. Thus, the available data suggest a favorable benefit-risk ratio for the new substances in addition to improved patient comfort. Currently unresolved issues relate to the verification of patient adherence by suitable coagulation tests and to the emergency coagulation diagnostics and therapy in acute ischemic or hemorrhagic strokes under the new OAC.

  13. Atrial fibrillation: review of current treatment strategies.

    PubMed

    Xu, Joshua; Luc, Jessica G Y; Phan, Kevin

    2016-09-01

    Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia in modern clinical practice, with an estimated prevalence of 1.5-2%. The prevalence of AF is expected to double in the next decades, progressing with age and increasingly becoming a global medical challenge. The first-line treatment for AF is often medical treatment with either rate control or anti-arrhythmic agents for rhythm control, in addition to anti-coagulants such as warfarin for stroke prevention in patient at risk. Catheter ablation has emerged as an alternative for AF treatment, which involves myocardial tissue lesions to disrupt the underlying triggers and substrates for AF. Surgical approaches have also been developed for treatment of AF, particularly for patients requiring concomitant cardiac surgery or those refractory to medical and catheter ablation treatments. Since the introduction of the Cox-Maze III, this procedure has evolved into several modern variations, including the use of alternative energy sources (Cox-Maze IV) such as radiofrequency, cryo-energy and microwave, as well as minimally invasive thoracoscopic epicardial approaches. Another recently introduced technique is the hybrid ablation approach, where in a single setting both epicardial thoracoscopic ablation lesions and endocardial catheter ablation lesions are performed by the cardiothoracic surgeon and cardiologist. There remains controversy surrounding the optimal approach for AF ablation, energy sources, and lesion sets employed. The goal of this article is review the history, classifications, pathophysiology and current treatment options for AF.

  14. Atrial septal defect repair gone wrong.

    PubMed

    Bloomingdale, Richard; Ashraf, Said; Cardozo, Shaun

    2017-02-01

    Isolated atrial septal defect (ASD) accounts for 13% of congenital heart disorders. The anatomic location, size, and coexistence of other cardiac anomalies determine outcomes of repair. Surgical closure was the first-choice treatment until the 1990s and remains the only treatment for large defects. We describe a case of a 64-year-old woman who underwent surgical repair for an ASD as a child in 1959. She presented with dyspnea to the hospital almost 53 years after the surgery. Diagnostic cardiac imaging revealed interesting anatomy of the repair surgery. Transthoracic echocardiography showed areas of flow signal across the patch consistent with surgical perforation of the patch to reduce symptoms of superior vena cava (SVC) syndrome. Despite intervention, severe dilation of the SVC along with a thrombus is seen. CT angiography of the heart showed the ASD patch occluding the ostium of the SVC instead of patching the ASD. Transesophageal echocardiography showed malpositioned patch allowing the sinus venosus ASD to remain patent.

  15. Predicting atrial fibrillation and its complications

    PubMed Central

    Alonso, Alvaro; Norby, Faye L.

    2016-01-01

    Atrial fibrillation (AF) is a common cardiac arrhythmia associated with an increased risk of stroke and other complications. Identifying individuals at higher risk of developing AF in the community is now possible using validated predictive models that take into account clinical variables and circulating biomarkers. These models have shown adequate performance in racially and ethnically diverse populations. Similarly, risk stratification schemes predict incidence of ischemic stroke in persons with AF, assisting clinicians and patients in decisions regarding oral anticoagulation use. Complementary schemes have been developed to predict the risk of bleeding in AF patients taking vitamin K antagonists. However, major gaps in our ability to predict AF and its complications exist. Additional research should refine models for AF prediction and determine their value to improve population health and clinical outcomes, advance our ability to predict stroke and other complications in AF patients, and develop predictive models for bleeding events and other adverse effects in patients using non-vitamin K oral anticoagulants. PMID:27008924

  16. Atrial natriuretic factor increases vascular permeability

    NASA Technical Reports Server (NTRS)

    Lockette, Warren; Brennaman, Bruce

    1990-01-01

    An increase in central blood volume in microgravity may result in increased plasma levels of atrial natriuretic factor (ANF). In this study, it was determined whether ANF increases capillary permeability to plasma protein. Conscious, bilaterally nephrectomized male rats were infused with either saline, ANF + saline, or hexamethonium + saline over 2 h following bolus injections of (I-125)-albumin and (C-14)-dextran of similar molecular size. Blood pressure was monitored, and serial determinations of hematocrits were made. Animals infused with 1.0 microg/kg per min ANF had significantly higher hematocrits than animals infused with saline vehicle. Infusion of ANF increased the extravasation of (I-125)-albumin, but not (C-14)-dextran from the intravascular compartment. ANF also induced a depressor response in rats, but the change in blood pressure did not account for changes in capillary permeability to albumin; similar depressor responses induced by hexamethonium were not accompanied by increased extravasation of albumin from the intravascular compartment. ANF may decrease plasma volume by increasing permeability to albumin, and this effect of ANF may account for some of the signs and symptoms of space motion sickness.

  17. Atrial fibrillation: review of current treatment strategies

    PubMed Central

    Xu, Joshua; Luc, Jessica G. Y.

    2016-01-01

    Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia in modern clinical practice, with an estimated prevalence of 1.5–2%. The prevalence of AF is expected to double in the next decades, progressing with age and increasingly becoming a global medical challenge. The first-line treatment for AF is often medical treatment with either rate control or anti-arrhythmic agents for rhythm control, in addition to anti-coagulants such as warfarin for stroke prevention in patient at risk. Catheter ablation has emerged as an alternative for AF treatment, which involves myocardial tissue lesions to disrupt the underlying triggers and substrates for AF. Surgical approaches have also been developed for treatment of AF, particularly for patients requiring concomitant cardiac surgery or those refractory to medical and catheter ablation treatments. Since the introduction of the Cox-Maze III, this procedure has evolved into several modern variations, including the use of alternative energy sources (Cox-Maze IV) such as radiofrequency, cryo-energy and microwave, as well as minimally invasive thoracoscopic epicardial approaches. Another recently introduced technique is the hybrid ablation approach, where in a single setting both epicardial thoracoscopic ablation lesions and endocardial catheter ablation lesions are performed by the cardiothoracic surgeon and cardiologist. There remains controversy surrounding the optimal approach for AF ablation, energy sources, and lesion sets employed. The goal of this article is review the history, classifications, pathophysiology and current treatment options for AF. PMID:27747025

  18. Beetroot supplementation lowers daily systolic blood pressure in older, overweight subjects.

    PubMed

    Jajja, A; Sutyarjoko, A; Lara, J; Rennie, K; Brandt, K; Qadir, O; Siervo, M

    2014-10-01

    Although inorganic nitrate and beetroot juice supplementation are associated with decreased systolic blood pressure (BP), these results have primarily been obtained from short-term trials that focused on healthy young adults. Therefore, we hypothesized that oral supplementation of beetroot juice concentrate would decrease systolic BP in overweight older participants but that the decline in BP would not be sustained after a 1-week interruption of the beetroot juice supplementation. For 3 weeks, 24 participants were randomized to either the beetroot juice concentrate or blackcurrant juice group, with a 1-week postsupplementation phase (week 4). Changes in systolic and diastolic BP were assessed during the supplementation and postsupplementation phases. Blood pressure was measured using 3 different methods: (1) resting clinic BP, (2) 24-hour ambulatory BP monitoring, and (3) home monitoring of daily resting BP. The first 2 methods were applied at baseline and after weeks 3 and 4. Daily measurements were conducted throughout the study, with 21 subjects completing the study (beetroot/blackcurrant = 10/11; male/female = 12/9; age = 62.0 ± 1.4 years; body mass index = 30.1 ± 1.2 kg/m(2)). After 3 weeks, beetroot juice supplementation was not associated with significant changes in resting clinic BP or 24-hour ABPM. Conversely, beetroot juice concentrate reduced daily systolic BP after 3 weeks (-7.3 ± 5.9 mm Hg, P = .02); however, the effect was not maintained after the interruption of the supplementation (week 4, 2.8 ± 6.1 mm Hg, P = .09). In overweight older subjects, beetroot juice concentrate supplementation was associated with beneficial effects on daily systolic BP, although the effects were not significant when measured by 24-hour ABPM or resting clinic BP.

  19. Characteristic systolic waveform of left ventricular longitudinal strain rate in patients with hypertrophic cardiomyopathy.

    PubMed

    Okada, Kazunori; Kaga, Sanae; Mikami, Taisei; Masauzi, Nobuo; Abe, Ayumu; Nakabachi, Masahiro; Yokoyama, Shinobu; Nishino, Hisao; Ichikawa, Ayako; Nishida, Mutsumi; Murai, Daisuke; Hayashi, Taichi; Shimizu, Chikara; Iwano, Hiroyuki; Yamada, Satoshi; Tsutsui, Hiroyuki

    2016-10-18

    We analyzed the waveform of systolic strain and strain-rate curves to find a characteristic left ventricular (LV) myocardial contraction pattern in patients with hypertrophic cardiomyopathy (HCM), and evaluated the utility of these parameters for the differentiation of HCM and LV hypertrophy secondary to hypertension (HT). From global strain and strain-rate curves in the longitudinal and circumferential directions, the time from mitral valve closure to the peak strains (T-LS and T-CS, respectively) and the peak systolic strain rates (T-LSSR and T-CSSR, respectively) were measured in 34 patients with HCM, 30 patients with HT, and 25 control subjects. The systolic strain-rate waveform was classified into 3 patterns ("V", "W", and "√" pattern). In the HCM group, T-LS was prolonged, but T-LSSR was shortened; consequently, T-LSSR/T-LS ratio was distinctly lower than in the HT and control groups. The "√" pattern of longitudinal strain-rate waveform was more frequently seen in the HCM group (74 %) than in the control (4 %) and HT (20 %) groups. Similar but less distinct results were obtained in the circumferential direction. To differentiate HCM from HT, the sensitivity and specificity of the T-LSSR/T-LS ratio <0.34 and the "√"-shaped longitudinal strain-rate waveform were 85 and 63 %, and 74 and 80 %, respectively. In conclusion, in patients with HCM, a reduced T-LSSR/T-LS ratio and a characteristic "√"-shaped waveform of LV systolic strain rate was seen, especially in the longitudinal direction. The timing and waveform analyses of systolic strain rate may be useful to distinguish between HCM and HT.

  20. Chronic pulmonary hypertension shortens the duration of mitral annular systolic and diastolic tissue Doppler signals.

    PubMed

    López-Candales, Angel; Edelman, Kathy; Gulyasy, Beth; Candales, Maria Dolores

    2012-03-01

    Some data suggests that both left ventricular (LV) systolic and diastolic function are impaired in patients with chronic pulmonary hypertension (cPH); however, a clear understanding of these specific abnormalities remains poorly characterized. LV systolic and diastolic function as well as LV myocardial performance index (MPI) were obtained and compared to total duration of mitral annular (MA) TDI systolic (MASTDId) and diastolic (MADTDId) measurements, corrected for heart rate, in 20 controls (Group I: mean 53 ± 18 years) and 30 patients (Group II: mean 55 ± 14 years) with cPH. Group II patients had relatively faster heart rates (75 ± 14 bpm vs. 63 ± 12 bpm; P < 0.003), higher LV ejection fraction (78 ± 10% vs. 68 ± 6%; P < 0.0004), similar MA systolic excursion (1.4 ± 0.2), unchanged MA TDI Ea/Aa ratios (0.86 ± 0.46 vs. 1.05 ± 0.41; P = 0.15), significantly higher LV MPI (0.98 ± 0.56 vs. 0.60 ± 0.11; P < 0.004), with a significantly shorter heart rate corrected MASTDId (251 ± 66 ms vs. 305 ± 30 ms; P < 0.001) and MADTDId (378 ± 87 ms vs. 497 ± 114 ms; P < 0.0001) than Group I. It appears that cPH shortens the total duration of both MA systolic and diastolic TDI intervals. Whether this is a result of altered LV geometry and/or confounded by the presence of relatively faster heart rates in cPH patients will require further study.

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

    PubMed Central

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

    2011-01-01

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

  2. Principal component analysis of atrial fibrillation: Inclusion of posterior ECG leads does not improve correlation with left atrial activity

    PubMed Central

    Raine, Daniel; Langley, Philip; Shepherd, Ewen; Lord, Stephen; Murray, Stephen; Murray, Alan; Bourke, John P.

    2015-01-01

    Background Lead V1 is routinely analysed due to its large amplitude AF waveform. V1 correlates strongly with right atrial activity but only moderately with left atrial activity. Posterior lead V9 correlates strongest with left atrial activity. Aims (1) To establish whether surface dominant AF frequency (DAF) calculated using principal component analysis (PCA) of a modified 12-lead ECG (including posterior leads) has a stronger correlation with left atrial activity compared to the standard ECG. (2) To assess the contribution of individual ECG leads to the AF principal component in both ECG configurations. Methods Patients were assigned to modified or standard ECG groups. In the modified ECG, posterior leads V8 and V9 replaced V4 and V6. AF waveform was extracted from one-minute surface ECG recordings using PCA. Surface DAF was correlated with intracardiac DAF from the high right atrium (HRA), coronary sinus (CS) and pulmonary veins (PVs). Results 96 patients were studied. Surface DAF from the modified ECG did not have a stronger correlation with left atrial activity compared to the standard ECG. Both ECG configurations correlated strongly with HRA, CS and right PVs but only moderately with left PVs. V1 contributed most to the AF principal component in both ECG configurations. PMID:25619612

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

    PubMed Central

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

    2016-01-01

    Atrial fibrillation (AF), the most common arrhythmia, is a growing epidemic with substantial morbidity and economic burden. Mechanisms underlying vulnerability to AF remain poorly understood, which contributes to the current lack of highly effective therapies. Recognizing mechanistic subtypes of AF may guide an individualized approach to patient management. Here, we describe a family with a previously unreported syndrome characterized by early-onset AF (age <35 years), conduction disease and signs of a primary atrial myopathy. Phenotypic penetrance was complete in all mutation carriers, although complete disease expressivity appears to be age-dependent. We show that this syndrome is caused by a novel, heterozygous p.Glu11Lys mutation in the atrial-specific myosin light chain gene MYL4. In zebrafish, mutant MYL4 leads to disruption of sarcomeric structure, atrial enlargement and electrical abnormalities associated with human AF. These findings describe the cause of a rare subtype of AF due to a primary, atrial-specific sarcomeric defect. PMID:27066836

  4. Computational modeling of the human atrial anatomy and electrophysiology.

    PubMed

    Dössel, Olaf; Krueger, Martin W; Weber, Frank M; Wilhelms, Mathias; Seemann, Gunnar

    2012-08-01

    This review article gives a comprehensive survey of the progress made in computational modeling of the human atria during the last 10 years. Modeling the anatomy has emerged from simple "peanut"-like structures to very detailed models including atrial wall and fiber direction. Electrophysiological models started with just two cellular models in 1998. Today, five models exist considering e.g. details of intracellular compartments and atrial heterogeneity. On the pathological side, modeling atrial remodeling and fibrotic tissue are the other important aspects. The bridge to data that are measured in the catheter laboratory and on the body surface (ECG) is under construction. Every measurement can be used either for model personalization or for validation. Potential clinical applications are briefly outlined and future research perspectives are suggested.

  5. Biological Therapies for Atrial Fibrillation: Ready for Prime Time?

    PubMed

    Donahue, J Kevin

    2016-01-01

    Atrial fibrillation is a prominent cause of morbidity and mortality in developed countries. Treatment strategies center on controlling atrial rhythm or ventricular rate. The need for anticoagulation is an independent decision from the rate versus rhythm control debate. This review discusses novel biological strategies that have potential utility in the management of atrial fibrillation. Rate controlling strategies predominately rely on G-protein gene transfer to enhance cholinergic or suppress adrenergic signaling pathways in the atrioventricular node. Calcium channel blocking gene therapy and fibrosis enhancing cell therapy have also been reported. Rhythm controlling strategies focus on disrupting reentry by enhancing conduction or suppressing repolarization. Efforts to suppress inflammation and apoptosis are also under study. Resistance to blood clot formation has been shown with thrombomodulin. These strategies are in various stages of preclinical development.

  6. Novel Anticoagulants in Atrial Fibrillation: Monitoring, Reversal and Perioperative Management

    PubMed Central

    Shamoun, Fadi; Obeid, Hiba; Ramakrishna, Harish

    2015-01-01

    Atrial fibrillation continues to be a significant source of morbidity and mortality worldwide. Effective anticoagulation remains the cornerstone of outpatient and inpatient treatment. The use of the new generation of anticoagulants (NOACs) continues to grow. Recently published data indicate their cost-effectiveness and overall safety in stroke prevention; compared to vitamin K antagonists, they can be prescribed in fixed doses for long-term therapy without the need for coagulation monitoring. Both United States and European Guidelines recommend NOACs for stroke prevention in patients with atrial fibrillation. This review discusses each of the NOACs, along with their efficacy and safety data. It explores the most recent guidelines regarding their perioperative use in atrial fibrillation patients. It also discusses bleeding complications, perioperative management, and reversal agents. PMID:26221593

  7. Automatic Detection of Atrial Fibrillation for Mobile Devices

    NASA Astrophysics Data System (ADS)

    Kaiser, Stefanie; Kirst, Malte; Kunze, Christophe

    Two versions of a new detector for automatic real-time detection of atrial fibrillation in non-invasive ECG signals are introduced. The methods are based on beat to beat variability, tachogram analysis and simple signal filtering. The implementation on mobile devices is made possible due to the low demand on computing power of the employed analysis procedures. The proposed algorithms correctly identified 436 of 440 five minute episodes of atrial fibrillation or flutter and also correctly identified up to 302 of 342 episodes of no atrial fibrillation, including normal sinus rhythm as well as other cardiac arrhythmias. These numbers correspond to a sensitivity of 99.1 % and a specificity of 88.3%.

  8. Investigating relationships between left atrial volume, symmetry, and sphericity

    NASA Astrophysics Data System (ADS)

    Menon, Prahlad G.; Nedios, Sotiris; Hindricks, Gerhard; Bollmann, Andreas

    2016-03-01

    Catheter ablation is a safe and effective therapy for drug-refractory patients symptomatic of atrial fibrillation (AF), with up to 80% of patients experiencing long-term arrhythmia-free survival. However, up to 20-40% of patients require more than one procedure in order to become arrhythmia-free. Therefore, appropriate patient selection is paramount to the effective implementation and long-term success of ablation therapy for patients with atrial fibrillation (AF). In this study, as a precursor to evaluating clinical significance of specific LA shape metrics as pre-procedural predictors of AF recurrence following ablative pulmonary vein isolation therapy, we report on a computational geometric analysis in a pilot cohort evaluating relationships between various patient-specific metrics of LA shape which might have such predictive value. This study specifically is focused on establishing the relationship between LA volume and sphericity, using a novel methodology for computing atrial sphericity based on regional shape.

  9. Left Atrial Reverse Remodeling: Mechanisms, Evaluation, and Clinical Significance.

    PubMed

    Thomas, Liza; Abhayaratna, Walter P

    2017-01-01

    The left atrium is considered a biomarker for adverse cardiovascular outcomes, particularly in patients with left ventricular diastolic dysfunction and atrial fibrillation in whom left atrial (LA) enlargement is of prognostic importance. LA enlargement with a consequent decrease in LA function represents maladaptive structural and functional "remodeling" that in turn promotes electrical remodeling and a milieu conducive for incident atrial fibrillation. Medical and nonmedical interventions may arrest this pathophysiologic process to the extent that subsequent reverse remodeling results in a reduction in LA size and improvement in LA function. This review examines cellular and basic mechanisms involved in LA remodeling, evaluates the noninvasive techniques that can assess these changes, and examines potential mechanisms that may initiate reverse remodeling.

  10. Atrial Papillary Fibroelastoma: A Stranger in a Strange Place

    PubMed Central

    Haider, Imran; Kawsar, Hameem; Khattak, Himad; Siddiqui, Muhammad

    2015-01-01

    Papillary fibroelastoma (PFE) is the most common primary tumor of cardiac valves and predominantly located on the left side. Its origin from non-valvular endocardium is extremely rare. We describe a case of an 81-year-old Caucasian male who presented with a mobile right atrial mass at the junction of right atrial wall and superior vena cava (SVC). Initially it was thought to be a thrombus and the patient was treated with anti-coagulation therapy without any change in size of the mass. Surgical excision was performed to establish the diagnosis and histopathology confirmed the diagnosis of PFE. In conclusion, this case is unique due to location of the tumor and its attachment with superior vena cava. Physicians should consider this unusual location of PFE in the differential diagnoses of an intra-atrial mass. PMID:27326351

  11. A case of atrial tachycardia sensitive to increased caffeine intake.

    PubMed

    Kinugawa, Toru; Kurita, Takashi; Nohara, Ryuji; Smith, Michael L

    2011-01-01

    A 33-year-old Japanese man with atrial tachycardia visited our clinic. He regularly consumed daily alcohol with cola, one cup of regular coffee, and a candy containing 0.7 mg of caffeine per tablet. After stopping his caffeine intake, his arrhythmia ameliorated. Since caffeine might be associated with his arrhythmia, a caffeine load test (equivalent to his daily intake of caffeine) was performed for 4 days. Atrial tachycardia time from a Holter recording was 44.2 minute/day before the caffeine load, compared with 215.2 minute/day during the caffeine load. Plasma caffeine concentration before and during caffeine loading was 3.1 mg/dL and 5.4 mg/dL, respectively. Caffeine use seemed to be an important factor for his atrial tachycardia, since his arrhythmia became worse during caffeine load testing and was ameliorated after the cessation of caffeine.

  12. Diabetes mellitus and atrial remodeling: mechanisms and potential upstream therapies.

    PubMed

    Zhang, Qitong; Liu, Tong; Ng, Chee Y; Li, Guangping

    2014-10-01

    Atrial fibrillation (AF) is the most common cardiac arrhythmia in clinical practice, and its prevalence has increasing substantially over the last decades. Recent data suggest that there is an increased risk of AF among the patients with diabetes mellitus (DM). However, the potential molecular mechanisms regarding DM-related AF and diabetic atrial remodeling are not fully understood. In this comprehensive review, we would like to summarize the potential relationship between diabetes and atrial remodeling, including structural, electrical, and autonomic remodeling. Also, some upstream therapies, such as thiazolidinediones, probucol, ACEI/ARBs, may play an important role in the prevention and treatment of AF. Therefore, large prospective randomized, controlled trials and further experimental studies should be challengingly continued.

  13. Atrial Septal Defect in a Very Old Woman

    PubMed Central

    Pinho, Elika; Gomes, Andre Amaral; Silva, Maria Joao; Torres, Tiago Pinheiro; Coelho, Andreia; Almeida, Pedro Bernardo; Lourenco, Patricia; Bettencourt, Paulo

    2013-01-01

    Atrial Septal Defect (ASD) is one of the most frequently congenital heart diseases in adults and it is often asymptomatic until adulthood. We report a case of a 90-year-old woman admitted to hospital with dyspnea and orthopnea insidiously progressing over the preceding 5 years and becoming severe with dyspnea on minimal activities, orthopnea and paroxysmal nocturnal dyspnea, in the last 2 weeks. The transthoracic echocardiogram revealed an atrial septal defect ostium secundum type, with left-to-right shunt, moderate to severe tricuspid insufficiency, severe pulmonary hypertension (72 mmHg) and preserved biventricular function. With diuretic therapy optimization the patient showed symptomatic improvement. This present case represents and unusual and very late presentation of an atrial septal defect ostium secundum type, which is usually diagnosed at the mild adult age. Our patient lived symptom-free for over 80 years.

  14. Beat to beat wavelet variability in atrial fibrillation.

    PubMed

    Filos, D; Chouvarda, I; Dakos, G; Vassilikos, V; Maglaveras, N

    2011-01-01

    Atrial fibrillation (AF) is a complex phenomenon, related with a multitude of factors, including the electrical properties of the atrial substrate. The purpose of this work is to present a method that highlights electrocardiographic differences between normal subjects and patients with paroxysmal AF episodes (PAF), potentially related with substrate differences. Vectorcardiography recordings are considered and, for each lead (X-Y-Z), on a beat by beat basis, a steady window before QRS, corresponding to the atrial activity, is analysed via continuous wavelet transform. Wavelet-based parameters are calculated and compared between the normal and AF group, with the beat to beat variation of wavelet energy as the most important feature showing a significantly higher variability in the AF group.

  15. Dissection of the atrial wall after mitral valve replacement.

    PubMed Central

    Lukács, L; Kassai, I; Lengyel, M

    1996-01-01

    We describe an unusual sequela of mitral valve replacement in a 50-year-old woman who had undergone a closed mitral commissurotomy in 1975. She was admitted to our hospital because of mitral restenosis in November 1993, at which time her mitral valve was replaced with a mechanical prosthesis. On the 8th postoperative day, the patient developed symptoms of heart failure; transesophageal echocardiography revealed dissection and rupture of the left atrial wall. At prompt reoperation, we found an interlayer dissection and rupture of the atrial wall into the left atrium. We repaired the ruptured atrial wall with a prosthetic patch. The postoperative course was uneventful, and postoperative transesophageal echocardiography showed normal prosthetic valve function and no dissection. Images PMID:8680278

  16. Molecular dynamics in mouse atrial tumor sarcoplasmic reticulum.

    PubMed Central

    Voss, J C; Mahaney, J E; Jones, L R; Thomas, D D

    1995-01-01

    We have determined directly the effects of the inhibitory peptide phospholamban (PLB) on the rotational dynamics of the calcium pump (Ca-ATPase) of cardiac sarcoplasmic reticulum (SR). This was accomplished by comparing mouse ventricular SR, which has PLB levels similar to those found in other mammals, with mouse atrial SR, which is effectively devoid of PLB and thus has much higher (unregulated) calcium pump activity. To obtain sufficient quantities of atrial SR, we isolated the membranes from atrial tumor cells. We used time-resolved phosphorescence anisotropy of an erythrosin isothiocyanate label attached selectively and rigidly to the Ca-ATPase, to detect the microsecond rotational motion of the Ca-ATPase in the two preparations. The time-resolved phosphorescence anisotropy decays of both preparations at 25 degrees C were multi-exponential, because of the presence of different oligomeric species. The rotational correlation times for the different oligomers were similar for the two preparations, but the total decay amplitude was substantially greater for atrial tumor SR, indicating that a smaller fraction of the Ca-ATPase molecules exists as large aggregates. Phosphorylation of PLB in ventricular SR decreased the population of large-scale Ca-ATPase aggregates to a level similar to that of atrial tumor SR. Lipid chain mobility (fluidity), detected by electron paramagnetic resonance of stearic acid spin labels, was very similar in the two preparations, indicating that the higher protein mobility in atrial tumor SR is not due to higher lipid fluidity. We conclude that PLB inhibits by inducing Ca-ATPase lateral aggregation, which can be relieved either by phosphorylating or removing PLB. Images FIGURE 1 FIGURE 2 PMID:7612820

  17. The C of CHADS: Historical perspective and clinical applications for anticoagulation in patients with non valvular atrial fibrillation and congestive heart failure.

    PubMed

    Chugh, Y; Faillace, R T

    2016-12-01

    The risk stratification of patients with coexisting non valvular atrial fibrillation and congestive heart failure, is often a clinical challenge, as the definitions of congestive heart failure in the popular CHADS2 and CHA2DS2VASc scoring systems, and amongst major clinical trials on Warfarin and Novel Oral Anticoagulants (NOAC) have heterogeneity. Available evidence reveals that any heart failure and/or left ventricular systolic dysfunction is associated with higher rates of stroke/systemic embolism and bleeding in patients with non valvular atrial fibrillation compared to patients without heart failure and normal left ventricular function. Most standard dose NOAC regimens have a better safety and efficacy profile over warfarin in most heart failure sub-group types with a few exceptions including patients with NYHA III/IV on Dabigatran 150mg BID from the RE-LY trial, who had higher major bleeding events, and patients with asymptomatic left ventricular dysfunction (ejection fraction ≤40%) and heart failure with reduced ejection fraction on 20mg of Rivaroxaban in the ROCKET-AF trial, when compared to patients on Warfarin in the corresponding groups. With the gaining popularity and use of NOACs, understanding their safety profile in such situations is paramount.

  18. Epidemiology of atrial fibrillation in Spain in the past 20 years.

    PubMed

    Pérez-Villacastín, Julián; Pérez Castellano, Nicasio; Moreno Planas, Javier

    2013-07-01

    Atrial fibrillation is the most common sustained arrhythmia. Because of its potentially serious clinical consequences (heart failure, stroke, and cognitive impairment), atrial fibrillation has important socioeconomic and health implications. This article reviews the major studies on the epidemiology of atrial fibrillation in Spain. Recent data suggest that in people older than 40 years, the prevalence of atrial fibrillation may be more than 4%. Given the current Spanish demography, these data would imply that more than 1 million people in Spain have atrial fibrillation.

  19. Depression in Atrial Fibrillation in the General Population

    PubMed Central

    Wilde, Sandra; Wiltink, Jörg; Wild, Philipp S.; Sinning, Christoph R.; Lubos, Edith; Ojeda, Francisco M.; Zeller, Tanja; Munzel, Thomas; Blankenberg, Stefan; Beutel, Manfred E.

    2013-01-01

    Background Initial evidence suggests that depressive symptoms are more frequent in patients with atrial fibrillation. Data from the general population are limited. Methods and Results In 10,000 individuals (mean age 56±11 years, 49.4% women) of the population-based Gutenberg Health Study we assessed depression by the Patient Health Questionnaire (PHQ-9) and a history of depression in relation to manifest atrial fibrillation (n = 309 cases). The median (25th/75th percentile) PHQ-9 score of depressive symptoms was 4 (2/6) in atrial fibrillation individuals versus 3 (2/6) individuals without atrial fibrillation, . Multivariable regression analyses of the severity of depressive symptoms in relation to atrial fibrillation in cardiovascular risk factor adjusted models revealed a relation of PHQ-9 values and atrial fibrillation (odds ratio (OR) 1.04, 95% confidence interval (CI) 1.01–1.08; P = 0.023). The association was stronger for the somatic symptom dimension of depression (OR 1.08, 95% CI 1.02–1.15; P = 0.0085) than for cognitive symptoms (OR 1.05, 95% CI 0.98–1.11; P = 0.15). Results did not change markedly after additional adjustment for heart failure, partnership status or the inflammatory biomarker C-reactive protein. Both, self-reported physical health status, very good/good versus fair/bad, (OR 0.54, 95% CI 0.41–0.70; P<0.001) and mental health status (OR 0.61 (0.46–0.82); P = 0.0012) were associated with atrial fibrillation in multivariable-adjusted models. Conclusions In a population-based sample we observed a higher burden of depressive symptoms driven by somatic symptom dimensions in individuals with atrial fibrillation. Depression was associated with a worse perception of physical or mental health status. Whether screening and treatment of depressive symptoms modulates disease progression and outcome needs to be shown. PMID:24324579

  20. Left atrial appendage occlusion: A better alternative to anticoagulation?

    PubMed Central

    Akin, Ibrahim; Nienaber, Christoph A

    2017-01-01

    Non-valvular atrial fibrillation is associated with a significantly increased risk of embolic stroke due to blood clot forming predominantly in the left atrial appendage (LAA). Preventive measures to avoid embolic events are permanent administration of anticoagulants or surgical closure of the LAA. Various clinical trials provide evidence about safety, effectiveness and therapeutic success of LAA occlusion using various cardiac occluder devices. The use of such implants for interventional closure of the LAA is likely to become a valuable alternative for stroke prevention, especially in patients with contraindication for oral anticoagulation as safety, clinical benefit and cost-effectiveness of LAA occlusion has recently been demonstrated. PMID:28289527

  1. Cost analysis of radiofrequency catheter ablation for atrial fibrillation.

    PubMed

    Gorenek, Bulent; Kudaiberdieva, Gulmira

    2013-09-10

    Atrial fibrillation is the most common arrhythmia associated with increased mortality and morbidity. Its management requires high healthcare expenditures; 52%-70% of expenses for AF care are constituted by hospitalization costs. The current management strategies of pharmacological rhythm control and pharmacological or invasive rate control show no difference in impact on major outcomes in patients with AF. Radiofrequency catheter ablation (RFA) has been shown to reduce the risk of AF recurrence, improve quality of life and reduce hospitalization rate as compared to pharmacological rhythm control and rate control strategies. This review summarizes current knowledge on cost and cost-effectiveness analysis of RFA for patients with atrial fibrillation.

  2. Surgical Techniques Used for the Treatment of Atrial Fibrillation

    PubMed Central

    Robertson, Jason O.; Lawrance, Christopher P.; Maniar, Hersh S.; Damiano, Ralph J.

    2015-01-01

    The use of surgical lesion sets for the treatment of atrial fibrillati