68 research outputs found

    Meta-Analysis of the Relation of Body Mass Index to All-Cause and Cardiovascular Mortality and Hospitalization in Patients With Chronic Heart Failure

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    Clinical studies have indicated the existence of an "obesity paradox" in patients with chronic heart failure (HF), that is, reduced mortality in patients who have elevated body mass index (BMI) scores compared with normal-weight reference groups. The aim of this study was to investigate the relation of BMI with all-cause and cardiovascular (CV) mortality and hospitalization in patients with chronic HF though a systematic review and meta-analysis of published research. PubMed, the Cumulative Index to Nursing and Allied Health Literature, Cochrane Central, Scopus, web of science and Embase were searched for studies reporting rates of total mortality, cardiac mortality, and risk for hospitalization in patients with HF in various BMI categories

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

    Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

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    Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02

    ATLAS detector and physics performance: Technical Design Report, 1

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    The Funny current: cellular basis for control of heart rate

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    The 'funny' (pacemaker, I-f) current, first described almost 30 years ago in sinoatrial node (SAN) myocytes, is a mixed sodium/potassium inward current, activated on hyperpolarisation in the diastolic range of voltages. 'Funny' (f) channels are activated by intracellular cyclic adenosine monophosphate (cAMP) concentrations according to a mechanism mediating regulation of heart rate by the autonomic nervous system, as well as by voltage hyperpolarisation. Structural subunits of native f-channels are the hyperpolarisation-activated cyclic nucleotide-gated (HCN) channels; of the four HCN isoforms known, HCN4 is the most highly expressed in SAN tissue. The I-f current is a natural target in the search for drugs aimed specifically at affecting heart rate, given its function in pacemaking. Increased heart rate has a negative influence on clinical outcome in patients with cardiovascular disease, and indeed is also an established risk factor for cardiovascular and all-cause mortality in the general population. Clearly, therefore, independent reduction of heart rate, through inhibition of the I-f current, appears to be a suitable therapeutic option for patients with ischaemic heart disease. beta-Adrenoceptor antagonists (beta-blockers) reduce intracellular cAMP levels, and a substantial part of their negative chronotropic effect is therefore attributable to a reduction of the I-f current. However, neither beta-blockers nor Ca2+ channel antagonists, both of which have traditionally been used to reduce myocardial ischaemia, are 'pure' heart rate-lowering drugs. These agents may, in fact, have adverse cardiovascular and noncardiovascular effects. Conversely, the novel heart rate-reducing agent ivabradine is a specific blocker of f-channels, hence a selective inhibitor of the pacemaker I-f current in the SAN. Ivabradine slows heart rate by reducing the I-f current-regulated steepness of the diastolic depolarisation in SAN myocytes, thereby increasing diastolic duration, without altering action potential duration or causing negative inotropy. As such, ivabradine is particularly useful in patients with chronic stable angina pectoris. Further clinical studies are ongoing to evaluate the efficacy of ivabradine in patients with coronary heart disease, left ventricular dysfunction and heart failure. This short article reviews the current state of knowledge of the properties of the 'funny' current in relation to exploitation of the I-f function in pacemaking generation and modulation for the pharmacological control of heart rate

    Rationale and design of a randomized, double-blind, placebo-controlled outcome trial of ivabradine in chronic heart failure: the Systolic Heart Failure Treatment with the If Inhibitor Ivabradine Trial (SHIFT)

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    &lt;p&gt;&lt;b&gt;Aims&lt;/b&gt; Elevated heart rate is a significant marker for mortality and morbidity in cardiovascular disease including heart failure. Despite background treatment with a beta-blocker, many patients with heart failure and low ejection fraction maintain a heart rate above 70 b.p.m. Ivabradine reduces heart rate directly through inhibition of the If ionic current.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Methods&lt;/b&gt; SHIFT is a randomized, double-blind study designed to compare ivabradine with placebo on outcomes in patients with symptomatic chronic heart failure (NYHA class II–IV), left-ventricular ejection fraction &#x2264;35%, and a prior hospitalization for worsening heart failure within the previous 12 months. Randomized treatment is given on top of guidelines-based therapy for chronic heart failure, including a beta-blocker at optimized dose. Resting heart rate at baseline must be &#x2265;70 b.p.m. The primary endpoint is the composite of the time to first event of cardiovascular death or hospitalization for worsening heart failure. Secondary endpoints include all-cause, cardiovascular and heart failure mortality, and hospitalization. The randomized treatment period lasts approximately 12–48 months. The study will include approximately 6500 patients and will continue until &#x2265;1600 primary endpoints have occurred. The first patient was randomized in October 2006, and the study is expected to end in 2010.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Conclusion&lt;/b&gt; The SHIFT study will assess if a heart rate reduction by direct sinus node inhibition can reduce cardiovascular outcomes in patients with chronic heart failure and left-ventricular systolic dysfunction.&lt;/p&gt

    Anxiety and Cardiovascular Symptoms: The Modulating Role of Insomnia

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    BACKGROUND: Anxiety and insomnia are associated with cardiovascular (CV) symptoms. We assessed whether the relation between anxiety and CV symptoms is modulated by insomnia. METHODS: Independently living women (n = 1,440; mean age = 59.36 ± 6.53 years) were recruited by cluster sampling technique. We obtained data on demographic characteristics, health beliefs, access to health care, CV symptoms, sleep, stress and anxiety levels. RESULTS: Overall, 56% of the sample reported insomnia; 46% reported CV symptoms, and 54% were highly anxious. There was a greater likelihood for highly anxious women and those experiencing insomnia to report CV symptoms (r(s) = 0.31∗ and r(s) = 0.32∗, respectively). In logistic regression analysis, the adjusted odds ratios for reporting CV symptoms were 1.39 for patients with insomnia and 2.79 for those with anxiety. With control for insomnia, we observed a 3-fold reduction in the magnitude of the association between anxiety and CV symptoms (r(p) = 0.09∗). Stepwise adjustments for sociodemographic factors, CV risk markers, and factors anchoring health beliefs and access to health care showed lesser impact on the relationships. With simultaneous control for those covariates, the correlation was r(p) = 0.13∗; ∗ p < 0.01. CONCLUSION: The association of CV symptoms with anxiety is partly accounted for by insomnia
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