22 research outputs found

    Long-Term Follow-Up In Paroxysmal Atrial Fibrillation Patients With Documented Isolated Trigger

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    AimsSupraventricular tachycardias may trigger atrial fibrillation (AF). The aim of the study was to evaluate the prevalence of supraventricular tachycardia (SVT) inducibility in patients referred for AF ablation and to evaluate the effects of SVT ablation on AF recurrences.Methods and results249 patients (mean age: 54 ± 14 years) referred for paroxysmal AF ablation were studied. In all patients, only AF relapses had been documented in the clinical history. 47 patients (19%; mean age: 42 ± 11 years) had inducible SVT during the electrophysiological study and underwent an ablation targeted only at SVT suppression. Ablation was successful in all 47 patients. The ablative procedures were: 11 slow-pathway ablations for atrioventricular nodal re-entrant tachycardia; 6 concealed accessory pathway ablations for atrioventricular re-entrant tachycardia; 17 focal ectopic atrial tachycardia ablations; 13 with only one arrhythmogenic pulmonary vein. No recurrences of SVT were observed during the follow-up (32 ± 18 months). 4 patients (8.5%) showed recurrence of at least one episode of AF. Patients with inducible SVT had less structural heart disease and were younger than those without inducible SVT.ConclusionA significant proportion of candidates for AF ablation are inducible for an SVT. SVT ablation showed a preventive effect on AF recurrences. Those patients should be selected for simpler ablation procedures tailored only to the triggering arrhythmia suppression

    Long-term follow-up in paroxysmal atrial fibrillation patients with documented isolated trigger

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    Aims: Supraventricular tachycardias may trigger atrial fibrillation (AF). The aim of the study was to evaluate the prevalence of supraventricular tachycardia (SVT) inducibility in patients referred for AF ablation and to evaluate the effects of SVT ablation on AF recurrences. Methods and results: 249 patients (mean age: 54 ± 14 years) referred for paroxysmal AF ablation were studied. In all patients, only AF relapses had been documented in the clinical history. 47 patients (19%; mean age: 42 ± 11 years) had inducible SVT during the electrophysiological study and underwent an ablation targeted only at SVT suppression. Ablation was successful in all 47 patients. The ablative procedures were: 11 slow-pathway ablations for atrioventricular nodal re-entrant tachycardia; 6 concealed accessory pathway ablations for atrioventricular re-entrant tachycardia; 17 focal ectopic atrial tachycardia ablations; 13 with only one arrhythmogenic pulmonary vein. No recurrences of SVT were observed during the follow-up (32 ± 18 months). 4 patients (8.5%) showed recurrence of at least one episode of AF. Patients with inducible SVT had less structural heart disease and were younger than those without inducible SVT. Conclusion: A significant proportion of candidates for AF ablation are inducible for an SVT. SVT ablation showed a preventive effect on AF recurrences. Those patients should be selected for simpler ablation procedures tailored only to the triggering arrhythmia suppression

    IVABRADINE AND DIASTOLIC HEART FAILURE

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    Development of the multi-mode horn-lens configuration for the LSPE-SWIPE B-mode experiment

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    The Large Scale Polarisation Explorer (LSPE) is a balloon-borne experiment aiming to measure the B-mode component of the CMB polarisation at large angular scales. Onboard LSPE, the Short Wavelength Instrument for the Polarisation Explorer (SWIPE) is a bolometric polarimeter observing in three bands centred at 140, 220 and 240 GHz. The telescope is a single large-diameter plano-convex lens with a cold aperture stop. A small number of multi-mode feed horns feeding bolometric detectors are used within the focal plane, achieving a sensitivity equivalent to that of 100’s of single-mode horns. Simulations have been performed to predict the multi-mode optical response of the horn-lens configuration for centre and off-axis pixels pertaining to each frequency band. The horn has been simulated to a high accuracy using the Method of Moments. Using the horn simulation result as a source, the optical response of the lens has been examined using the more approximate simulation technique; Ray-Launching Geometrical Optics (RL-GO). Solution accuracy and simulation time depend heavily on the choice of RL-GO simulation parameters including: mesh size; the number of launched rays; and how densely the horn source beam is sampled. Individual convergence studies have been performed for each of these parameters and a final model has been obtained as a compromise between simulation time and accuracy. The instrumental polarisation of the lens is predicted to be at the -50 dB level. Finally, the optimal location of where to place the telescope focus in relation to the horn to maximise on-axis gain has been investigated. Several techniques agreed that the ‘phase centre’ is around 20 mm behind the horn aperture at 140 GHz, increasing to 30 mm at 220 and 240 GHz. Taking into account beam truncation effects caused by the finite size of the telescope was found to reduce the overall variation in on-axis gain

    Real-Life Clinical Data of Lenvatinib versus Sorafenib for Unresectable Hepatocellular Carcinoma in Italy

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    Background: Lenvatinib has been approved in Italy since October 2019 as a first-line therapy for advanced hepatocellular carcinoma (HCC) and to date data on effectiveness and safety of lenvatinib are not available in our region. To fill this gap, we performed a multicentric analysis of the real-world treatment outcomes with the propensity score matching in a cohort of Italian patients with unresectable HCC who were treated with either sorafenib or lenvatinib. Aims and Methods: To evaluate the effectiveness of sorafenib and lenvatinib as primary treatment of advanced HCC in clinical practice we performed a multicentric analysis of the treatment outcomes of 288 such patients recruited in 11 centers in Italy. A propensity score was used to mitigate confounding due to referral biases in the assessment of mortality and progression-free survival. Results: Over a follow-up period of 11 months the Cox regression model showed 48% reduction of death risk for patients treated with lenvatinib (95% CI: 0.34-0.81; p = 0.0034), compared with those treated with sorafenib. The median PFS was 9.0 and 4.9 months for lenvatinib and sorafenib arm, respectively. Patients treated with lenvatinib showed a higher percentage of response rate (29.4% vs 2.8%; p < 0.00001) compared with patients treated with sorafenib. Sorafenib was shown to be correlated with more HFSR, diarrhea and fatigue, while lenvatinib with more hypertension and fatigue. Conclusion: Our study highlighted for the first time the efficacy and safety of lenvatinib in an Italian cohort of patients

    Thermal architecture for the QUBIC cryogenic receiver

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    QUBIC, the QU Bolometric Interferometer for Cosmology, is a novel forthcoming instrument to measure the B-mode polarization anisotropy of the Cosmic Microwave Background. The detection of the B-mode signal will be extremely challenging; QUBIC has been designed to address this with a novel approach, namely bolometric interferometry. The receiver cryostat is exceptionally large and cools complex optical and detector stages to 40 K, 4 K, 1 K and 350 mK using two pulse tube coolers, a novel 4He sorption cooler and a double-stage 3He/4He sorption cooler. We discuss the thermal and mechanical design of the cryostat, modelling and thermal analysis, and laboratory cryogenic testing

    Performance of NbSi transition-edge sensors readout with a 128 MUX factor for the QUBIC experiment

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    QUBIC (the Q and U Bolometric Interferometer for Cosmology) is a ground-based experiment which seeks to improve the current constraints on the amplitude of primordial gravitational waves. It exploits the unique technique, among Cosmic Microwave Background experiments, of bolometric interferometry, combining together the sensitivity of bolometric detectors with the control of systematic effects typical of interferometers. QUBIC will perform sky observations in polarization, in two frequency bands centered at 150 and 220 GHz, with two kilo-pixel focal plane arrays of NbSi Transition-Edge Sensors (TES) cooled down to 350 mK. A subset of the QUBIC instrument, the so called QUBIC Technological Demonstrator (TD), with a reduced number of detectors with respect to the full instrument, will be deployed and commissioned before the end of 2018. The voltage-biased TES are read out with Time Domain Multiplexing and an unprecedented multiplexing (MUX) factor equal to 128. This MUX factor is reached with two-stage multiplexing: a traditional one exploiting Superconducting QUantum Interference Devices (SQUIDs) at 1K and a novel SiGe Application-Specific Integrated Circuit (ASIC) at 60 K. The former provides a MUX factor of 32, while the latter provides a further 4. Each TES array is composed of 256 detectors and read out with four modules of 32 SQUIDs and two ASICs. A custom software synchronizes and manages the readout and detector operation, while the TES are sampled at 780 Hz (100kHz/128 MUX rate). In this work we present the experimental characterization of the QUBIC TES arrays and their multiplexing readout chain, including time constant, critical temperature, and noise properties

    QUBIC:Exploring the primordial universe with the Q&U bolometric interferometer

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    In this paper we describe QUBIC, an experiment that will observe the polarized microwave sky with a novel approach, which combines the sensitivity of state-of-the art bolometric detectors with the systematic effects control typical of interferometers. QUBIC unique features are the so-called "self-calibration", a technique that allows us to clean the measured data from instrumental effects, and its spectral imaging power, i.e. the ability to separate the signal in various sub-bands within each frequency band. QUBIC will observe the sky in two main frequency bands: 150 GHz and 220 GHz. A technological demonstrator is currently under testing and will be deployed in Argentina during 2019, while the final instrument is expected to be installed during 2020.Comment: Proceedings of the 2018 ICNFP conference, Crete. Published by Universe arXiv admin note: text overlap with arXiv:1801.0373

    QUBIC: the Q and U bolometric interferometer for cosmology

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    QUBIC, the Q & U Bolometric Interferometer for Cosmology, is a novel ground-based instrument that has been designed to measure the extremely faint B-mode polarisation anisotropy of the cosmic microwave background at intermediate angular scales (multipoles o
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