Differentiating wide complex tachycardias: A historical perspective

One of the most critical and challenging skills is the distinction of wide complex tachycardias into ventricular tachycardia or supraventricular wide complex tachycardia. Prompt and accurate differentiation of wide complex tachycardias naturally influences short- and long-term management decisions and may directly affect patient outcomes. Currently, there are many useful electrocardiographic criteria and algorithms designed to distinguish ventricular tachycardia and supraventricular wide complex tachycardia accurately; however, no single approach guarantees diagnostic certainty. In this review, we offer an in-depth analysis of available methods to differentiate wide complex tachycardias by retrospectively examining its rich literature base - one that spans several decades

Automatic wide complex tachycardia differentiation using mathematically synthesized vectorcardiogram signals

BACKGROUND: Automated wide complex tachycardia (WCT) differentiation into ventricular tachycardia (VT) and supraventricular wide complex tachycardia (SWCT) may be accomplished using novel calculations that quantify the extent of mean electrical vector changes between the WCT and baseline electrocardiogram (ECG). At present, it is unknown whether quantifying mean electrical vector changes within three orthogonal vectorcardiogram (VCG) leads (X, Y, and Z leads) can improve automated VT and SWCT classification. METHODS: A derivation cohort of paired WCT and baseline ECGs was used to derive five logistic regression models: (i) one novel WCT differentiation model (i.e., VCG Model), (ii) three previously developed WCT differentiation models (i.e., WCT Formula, VT Prediction Model, and WCT Formula II), and (iii) one all-inclusive model (i.e., Hybrid Model). A separate validation cohort of paired WCT and baseline ECGs was used to trial and compare each model\u27s performance. RESULTS: The VCG Model, composed of WCT QRS duration, baseline QRS duration, absolute change in QRS duration, X-lead QRS amplitude change, Y-lead QRS amplitude change, and Z-lead QRS amplitude change, demonstrated effective WCT differentiation (area under the curve [AUC] 0.94) for the derivation cohort. For the validation cohort, the diagnostic performance of the VCG Model (AUC 0.94) was similar to that achieved by the WCT Formula (AUC 0.95), VT Prediction Model (AUC 0.91), WCT Formula II (AUC 0.94), and Hybrid Model (AUC 0.95). CONCLUSION: Custom calculations derived from mathematically synthesized VCG signals may be used to formulate an effective means to differentiate WCTs automatically

Comparison of a nurse initiated insulin infusion protocol for intensive insulin therapy between adult surgical trauma, medical and coronary care intensive care patients

<p>Abstract</p> <p>Background</p> <p>Sustained hyperglycemia is a known risk factor for adverse outcomes in critically ill patients. The specific aim was to determine if a nurse initiated insulin infusion protocol (IIP) was effective in maintaining blood glucose values (BG) within a target goal of 100–150 mg/dL across different intensive care units (ICUs) and to describe glycemic control during the 48 hours after protocol discontinuation.</p> <p>Methods</p> <p>A descriptive, retrospective review of 366 patients having 28,192 blood glucose values in three intensive care units, Surgical Trauma Intensive Care Unit (STICU), Medical (MICU) and Coronary Care Unit (CCU) in a quaternary care hospital was conducted. Patients were > 15 years of age, admitted to STICU (n = 162), MICU (n = 110) or CCU (n = 94) over 8 months; October 2003-June 2004 and who had an initial blood glucose level > 150 mg/dL. We summarized the effectiveness and safety of a nurse initiated IIP, and compared these endpoints among STICU, MICU and CCU patients.</p> <p>Results</p> <p>The median blood glucose values (mg/dL) at initiation of insulin infusion protocol were lower in STICU (188; IQR, 162–217) than in MICU, (201; IQR, 170–268) and CCU (227; IQR, 178–313); <it>p </it>< 0.0001. Mean time to achieving a target glucose level (100–150 mg/dL) was similar between the three units: 4.6 hours in STICU, 4.7 hours in MICU and 4.9 hours in CCU (<it>p </it>= 0.27). Hypoglycemia (BG < 60 mg/dL) occurred in 7% of STICU, 5% of MICU, and 5% of CCU patients (<it>p </it>= 0.85). Protocol violations were uncommon in all three ICUs. Mean blood glucose 48 hours following IIP discontinuation was significantly different for each population: 142 mg/dL in STICU, 167 mg/dL in MICU, and 160 mg/dL in CCU (<it>p </it>< 0.0001).</p> <p>Conclusion</p> <p>The safety and effectiveness of nurse initiated IIP was similar across different ICUs in our hospital. Marked variability in glucose control after the protocol discontinuation suggests the need for further research regarding glucose control in patients transitioning out of the ICU.</p

Observation of High-Energy Astrophysical Neutrinos in Three Years of IceCube Data

A search for high-energy neutrinos interacting within the IceCube detector between 2010 and 2012 provided the first evidence for a high-energy neutrino flux of extraterrestrial origin. Results from an analysis using the same methods with a third year (2012-2013) of data from the complete IceCube detector are consistent with the previously reported astrophysical flux in the 100 TeV - PeV range at the level of $10^{-8}\, \mathrm{GeV}\, \mathrm{cm}^{-2}\, \mathrm{s}^{-1}\, \mathrm{sr}^{-1}$ per flavor and reject a purely atmospheric explanation for the combined 3-year data at $5.7 \sigma$. The data are consistent with expectations for equal fluxes of all three neutrino flavors and with isotropic arrival directions, suggesting either numerous or spatially extended sources. The three-year dataset, with a livetime of 988 days, contains a total of 37 neutrino candidate events with deposited energies ranging from 30 to 2000 TeV. The 2000 TeV event is the highest-energy neutrino interaction ever observed.Comment: 8 pages, 5 figures. Accepted by PRL. The event catalog, event displays, and other data tables are included after the final page of the article. Changed from the initial submission to reflect referee comments, expanding the section on atmospheric backgrounds, and fixes offsets of up to 0.9 seconds in reported event times. Address correspondence to: J. Feintzeig, C. Kopper, N. Whitehor

Differential limit on the extremely-high-energy cosmic neutrino flux in the presence of astrophysical background from nine years of IceCube data

We report a quasi-differential upper limit on the extremely-high-energy (EHE) neutrino flux above $5\times 10^{6}$ GeV based on an analysis of nine years of IceCube data. The astrophysical neutrino flux measured by IceCube extends to PeV energies, and it is a background flux when searching for an independent signal flux at higher energies, such as the cosmogenic neutrino signal. We have developed a new method to place robust limits on the EHE neutrino flux in the presence of an astrophysical background, whose spectrum has yet to be understood with high precision at PeV energies. A distinct event with a deposited energy above $10^{6}$ GeV was found in the new two-year sample, in addition to the one event previously found in the seven-year EHE neutrino search. These two events represent a neutrino flux that is incompatible with predictions for a cosmogenic neutrino flux and are considered to be an astrophysical background in the current study. The obtained limit is the most stringent to date in the energy range between $5 \times 10^{6}$ and $5 \times 10^{10}$ GeV. This result constrains neutrino models predicting a three-flavor neutrino flux of $E_\nu^2\phi_{\nu_e+\nu_\mu+\nu_\tau}\simeq2\times 10^{-8}\ {\rm GeV}/{\rm cm}^2\ \sec\ {\rm sr}$at$10^9\ {\rm GeV}$. A significant part of the parameter-space for EHE neutrino production scenarios assuming a proton-dominated composition of ultra-high-energy cosmic rays is excluded.Comment: The version accepted for publication in Physical Review

Cost-Effectiveness of New Cardiac and Vascular Rehabilitation Strategies for Patients with Coronary Artery Disease

Objective: Peripheral arterial disease (PAD) often hinders the cardiac rehabilitation program. The aim of this study was evaluating the relative cost-effectiveness of new rehabilitation strategies which include the diagnosis and treatment of PAD in patients with coronary artery disease (CAD) undergoing cardiac rehabilitation. Data Sources: Best-available evidence was retrieved from literature and combined with primary data from 231 patients. Methods: We developed a Markov decision model to compare the following treatment strategies: 1. cardiac rehabilitation only; 2. ankle-brachial index (ABI) if cardiac rehabilitation fails followed by diagnostic work-up and revascularization for PAD if needed; 3. ABI prior to cardiac rehabilitation followed by diagnostic work-up and revascularization for PAD if needed. Quality-adjusted-life years (QALYs), life-time costs (US $), incremental cost-effectiveness ratios (ICER), and gain in net health benefits (NHB) in QALY equivalents were calculated. A threshold willingness-to-pay of$75 000 was used. Results: ABI if cardiac rehabilitation fails was the most favorable strategy with an ICER of $44 251 per QALY gained and an incremental NHB compared to cardiac rehabilitation only of 0.03 QALYs (95$75 000/QALY. After sensitivity analysis, a combined cardiac and vascular rehabilitation program increased the success rate and would dominate the other two strategies with total lifetime costs of $30 246 a quality-adjusted life expectancy of 3.84 years, and an incremental NHB of 0.06 QALYs (95%CI:−0.24, 0.46) compared to current practice. The results were robust for other different input parameters. Conclusion: ABI measurement if cardiac rehabilitation fails followed by a diagnostic work-up and revascularization for PAD if needed are potentially cost-effective compared to cardiac rehabilitation only

Joint Constraints on Galactic Diffuse Neutrino Emission from the ANTARES and IceCube Neutrino Telescopes

[EN] The existence of diffuse Galactic neutrino production is expected from cosmic-ray interactions with Galactic gas and radiation ¿elds. Thus, neutrinos are a unique messenger offering the opportunity to test the products of Galactic cosmic-ray interactions up to energies of hundreds of TeV. Here we present a search for this production using ten years of Astronomy with a Neutrino Telescope and Abyss environmental RESearch (ANTARES) track and shower data, as well as seven years of IceCube track data. The data are combined into a joint likelihood test for neutrino emission according to the KRAg model assuming a 5 PeV per nucleon Galactic cosmic-ray cutoff. No signi¿cant excess is found. As a consequence, the limits presented in this Letter start constraining the model parameter space for Galactic cosmic-ray production and transport.Albert, A.; Andre, M.; Anghinolfi, M.; Ardid Ramírez, M.; Aubert, J-.; Aublin, J.; Avgitas, T.... (2018). Joint Constraints on Galactic Diffuse Neutrino Emission from the ANTARES and IceCube Neutrino Telescopes. The Astrophysical Journal. 868(2):1-7. https://doi.org/10.3847/2041-8213/aaeecfS178682Aartsen, M. G., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., Ahrens, M., … Anderson, T. (2017). Search for Astrophysical Sources of Neutrinos Using Cascade Events in IceCube. The Astrophysical Journal, 846(2), 136. doi:10.3847/1538-4357/aa8508Aartsen, M. G., Abraham, K., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., … Archinger, M. (2015). A COMBINED MAXIMUM-LIKELIHOOD ANALYSIS OF THE HIGH-ENERGY ASTROPHYSICAL NEUTRINO FLUX MEASURED WITH ICECUBE. The Astrophysical Journal, 809(1), 98. doi:10.1088/0004-637x/809/1/98Aartsen, M. G., Abraham, K., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., … Anderson, T. (2017). All-sky Search for Time-integrated Neutrino Emission from Astrophysical Sources with 7 yr of IceCube Data. The Astrophysical Journal, 835(2), 151. doi:10.3847/1538-4357/835/2/151Aartsen, M. G., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., Ahrens, M., … Anderson, T. (2017). Constraints on Galactic Neutrino Emission with Seven Years of IceCube Data. The Astrophysical Journal, 849(1), 67. doi:10.3847/1538-4357/aa8dfbAartsen, M. G., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., Ahrens, M., … Ansseau, I. (2017). The IceCube Neutrino Observatory: instrumentation and online systems. Journal of Instrumentation, 12(03), P03012-P03012. doi:10.1088/1748-0221/12/03/p03012Ackermann, M., Ajello, M., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., … Berenji, B. (2012). FERMI-LAT OBSERVATIONS OF THE DIFFUSE γ-RAY EMISSION: IMPLICATIONS FOR COSMIC RAYS AND THE INTERSTELLAR MEDIUM. The Astrophysical Journal, 750(1), 3. doi:10.1088/0004-637x/750/1/3Adrián-Martínez, S., Ageron, M., Aguilar, J. A., Samarai, I. A., Albert, A., André, M., … Ardid, M. (2012). The positioning system of the ANTARES Neutrino Telescope. Journal of Instrumentation, 7(08), T08002-T08002. doi:10.1088/1748-0221/7/08/t08002Ageron, M., Aguilar, J. A., Al Samarai, I., Albert, A., Ameli, F., André, M., … Ardid, M. (2011). ANTARES: The first undersea neutrino telescope. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 656(1), 11-38. doi:10.1016/j.nima.2011.06.103Ahn, H. S., Allison, P., Bagliesi, M. G., Beatty, J. J., Bigongiari, G., Childers, J. T., … Zinn, S. Y. (2010). DISCREPANT HARDENING OBSERVED IN COSMIC-RAY ELEMENTAL SPECTRA. The Astrophysical Journal, 714(1), L89-L93. doi:10.1088/2041-8205/714/1/l89Albert, A., André, M., Anghinolfi, M., Anton, G., Ardid, M., Aubert, J.-J., … Basa, S. (2017). New constraints on all flavor Galactic diffuse neutrino emission with the ANTARES telescope. Physical Review D, 96(6). doi:10.1103/physrevd.96.062001Antoni, T., Apel, W. D., Badea, A. F., Bekk, K., Bercuci, A., Blümer, J., … Zabierowski, J. (2005). KASCADE measurements of energy spectra for elemental groups of cosmic rays: Results and open problems. Astroparticle Physics, 24(1-2), 1-25. doi:10.1016/j.astropartphys.2005.04.001Apel, W. D., Arteaga-Velázquez, J. C., Bekk, K., Bertaina, M., Blümer, J., Bozdog, H., … Cossavella, F. (2013). KASCADE-Grande measurements of energy spectra for elemental groups of cosmic rays. Astroparticle Physics, 47, 54-66. doi:10.1016/j.astropartphys.2013.06.004Gaggero, D., Grasso, D., Marinelli, A., Taoso, M., & Urbano, A. (2017). Diffuse Cosmic Rays Shining in the Galactic Center: A Novel Interpretation of H.E.S.S. and Fermi-LAT γ -Ray Data. Physical Review Letters, 119(3). doi:10.1103/physrevlett.119.031101Gaggero, D., Grasso, D., Marinelli, A., Urbano, A., & Valli, M. (2015). THE GAMMA-RAY AND NEUTRINO SKY: A CONSISTENT PICTURE OF FERMI -LAT, MILAGRO, AND ICECUBE RESULTS. The Astrophysical Journal, 815(2), L25. doi:10.1088/2041-8205/815/2/l25Gaggero, D., Urbano, A., Valli, M., & Ullio, P. (2015). Gamma-ray sky points to radial gradients in cosmic-ray transport. Physical Review D, 91(8). doi:10.1103/physrevd.91.083012Vladimirov, A. E., Digel, S. W., Jóhannesson, G., Michelson, P. F., Moskalenko, I. V., Nolan, P. L., … Strong, A. W. (2011). GALPROP WebRun: An internet-based service for calculating galactic cosmic ray propagation and associated photon emissions. Computer Physics Communications, 182(5), 1156-1161. doi:10.1016/j.cpc.2011.01.01

Investigation of two Fermi-LAT gamma-ray blazars coincident with high-energy neutrinos detected by IceCube

After the identification of the gamma-ray blazar TXS 0506+056 as the first compelling IceCube neutrino source candidate, we perform a systematic analysis of all high-energy neutrino events satisfying the IceCube realtime trigger criteria. We find one additional known gamma-ray source, the blazar GB6 J1040+0617, in spatial coincidence with a neutrino in this sample. The chance probability of this coincidence is 30% after trial correction. For the first time, we present a systematic study of the gamma-ray flux, spectral and optical variability, and multi-wavelength behavior of GB6 J1040+0617 and compare it to TXS 0506+056. We find that TXS 0506+056 shows strong flux variability in the Fermi-LAT gamma-ray band, being in an active state around the arrival of IceCube-170922A, but in a low state during the archival IceCube neutrino flare in 2014/15. In both cases the spectral shape is statistically compatible ($\leq 2\sigma$) with the average spectrum showing no indication of a significant relative increase of a high-energy component. While the association of GB6 J1040+0617 with the neutrino is consistent with background expectations, the source appears to be a plausible neutrino source candidate based on its energetics and multi-wavelength features, namely a bright optical flare and modestly increased gamma-ray activity. Finding one or two neutrinos originating from gamma-ray blazars in the given sample of high-energy neutrinos is consistent with previously derived limits of neutrino emission from gamma-ray blazars, indicating the sources of the majority of cosmic high-energy neutrinos remain unknown.Comment: 22 pages, 11 figures, 2 Table

Extensive MIS 3 glaciation in southernmost Patagonia revealed by cosmogenic nuclide dating of outwash sediments

The timing and extent of former glacial advances can demonstrate leads and lags during periods of climatic change and their forcing, but this requires robust glacial chronologies. In parts of southernmost Patagonia, dating pre-global Last Glacial Maximum (gLGM) ice limits has proven difficult due to post-deposition processes affecting the build-up of cosmogenic nuclides in moraine boulders. Here we provide ages for the Río Cullen and San Sebastián glacial limits of the former Bahía Inútil–San Sebastián (BI-SSb) ice lobe on Tierra del Fuego (53–54°S), previously hypothesised to represent advances during Marine Isotope Stages (MIS) 12 and 10, respectively. Our approach uses cosmogenic 10Be and 26Al exposure dating, but targets glacial outwash associated with these limits and uses depth-profiles and surface cobble samples, thereby accounting for surface deflation and inheritance. The data reveal that the limits formed more recently than previously thought, giving ages of 45.6 ka for the Río Cullen, and 30.1 ka for the San Sebastián limits. These dates indicate extensive glaciation in southern Patagonia during MIS 3, prior to the well-constrained, but much less extensive MIS 2 (gLGM) limit. This suggests the pattern of ice advances in the region was different to northern Patagonia, with the terrestrial limits relating to the last glacial cycle, rather than progressively less extensive glaciations over hundreds of thousands of years. However, the dates are consistent with MIS 3 glaciation elsewhere in the southern mid-latitudes, and the combination of cooler summers and warmer winters with increased precipitation, may have caused extensive glaciation prior to the gLGM

An eV-scale sterile neutrino search using eight years of atmospheric muon neutrino data from the IceCube Neutrino Observatory

The results of a 3+1 sterile neutrino search using eight years of data from the IceCube Neutrino Observatory are presented. A total of 305,735 muon neutrino events are analyzed in reconstructed energy-zenith space to test for signatures of a matter-enhanced oscillation that would occur given a sterile neutrino state with a mass-squared differences between 0.01\,eV$^2$ and 100\,eV$^2$. The best-fit point is found to be at $\sin^2(2\theta_{24})=0.10$ and $\Delta m_{41}^2 = 4.5{\rm eV}^2$, which is consistent with the no sterile neutrino hypothesis with a p-value of 8.0\%.Comment: 11 pages, 5 figures. This letter is supported by the long-form paper "Searching for eV-scale sterile neutrinos with eight years of atmospheric neutrinos at the IceCube neutrino telescope," also appearing on arXiv. Digital data release available at: https://github.com/icecube/HE-Sterile-8year-data-releas