2,121 research outputs found

    Electromechanical reciprocity and arrhythmogenesis in long-QT syndrome and beyond.

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    An abundance of literature describes physiological and pathological determinants of cardiac performance, building on the principles of excitation-contraction coupling. However, the mutual influencing of excitation-contraction and mechano-electrical feedback in the beating heart, here designated 'electromechanical reciprocity', remains poorly recognized clinically, despite the awareness that external and cardiac-internal mechanical stimuli can trigger electrical responses and arrhythmia. This review focuses on electromechanical reciprocity in the long-QT syndrome (LQTS), historically considered a purely electrical disease, but now appreciated as paradigmatic for the understanding of mechano-electrical contributions to arrhythmogenesis in this and other cardiac conditions. Electromechanical dispersion in LQTS is characterized by heterogeneously prolonged ventricular repolarization, besides altered contraction duration and relaxation. Mechanical alterations may deviate from what would be expected from global and regional repolarization abnormalities. Pathological repolarization prolongation outlasts mechanical systole in patients with LQTS, yielding a negative electromechanical window (EMW), which is most pronounced in symptomatic patients. The electromechanical window is a superior and independent arrhythmia-risk predictor compared with the heart rate-corrected QT. A negative EMW implies that the ventricle is deformed-by volume loading during the rapid filling phase-when repolarization is still ongoing. This creates a 'sensitized' electromechanical substrate, in which inadvertent electrical or mechanical stimuli such as local after-depolarizations, after-contractions, or dyssynchrony can trigger abnormal impulses. Increased sympathetic-nerve activity and pause-dependent potentiation further exaggerate electromechanical heterogeneities, promoting arrhythmogenesis. Unraveling electromechanical reciprocity advances the understanding of arrhythmia formation in various conditions. Real-time image integration of cardiac electrophysiology and mechanics offers new opportunities to address challenges in arrhythmia management

    Long-term evaluation of polyethylene wear in total hip replacement : a statistical analysis of the association between the degree of wear versus pain, interface change, osteopysis and implant failure

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    With over 3.5 decades dedicated exclusively to total joint replacement, our arthroplasty unit has repeatedly identified and reported a clear correlation between cup wear on the one hand, and pain, interface widening and osteolytic failure on the other1. However, in view of the fact that this statement has sparked some controversy, clarification of this correlation became imperative, particularly in view of important clinical consequences. Materials and methods were provided by a potentially long-lasting gamma crosslinked cup. The arthroplasty follow- up ranged from 10-33 years. Objective clinical, radiographic and pathological evaluations were backed by computer analysis through the Department of Statistics at the University of Pretoria. We are able to conclude that the statistical correlation between wear, on the one hand, versus pain, interface effects and osteolysis on the other, was no coincidence but instead proved to be clearly conclusive. Of great importance is the fact that this study allowed us to set new objective criteria for true failure as well as impending failure, thus guiding us towards sensible decision-making in terms of revision surgery in these complex issues. Cup wear was thus clearly identified as the overwhelming leading variable in long-term prognosis in this type of total hip replacement.http://www.charpublications.co.za/C_JournalsORTH.as

    Barriers and Facilitators Associated With App-Based Treatment for Female Urinary Incontinence:Mixed Methods Evaluation

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    BACKGROUND: App-based treatment for urinary incontinence is a proven effective and cost-effective alternative to care as usual, but successful implementation requires that we identify and address the barriers and facilitators associated with app use. OBJECTIVE: The goal of the research was to explore the factors influencing app-based treatment for urinary incontinence and identify which barriers or facilitators are associated with treatment success or failure. METHODS: We used a sequential explanatory mixed methods design to connect the results of a randomized controlled trial with data from semistructured interviews. This previous RCT had shown the noninferiority of app-based treatment compared with care as usual for urinary incontinence over 4 months. Participants who reported success or failure with app-based treatment, as measured by the change in International Consultation on Incontinence Modular Questionnaire Urinary Incontinence Short Form symptom score, were selected for telephone interview by purposive sampling (n=17). This study reports mainly on the qualitative component of our mixed methods study. Qualitative analyses were conducted in two ways. First, we analyzed the qualitative data of all interviewed participants and discussed the relationships between the main themes. Second, the experiences between the success (n=9) and failure group (n=8) were compared and contrasted to explore factors that were positively or negatively associated with the quantitative effect of app-based treatment. These factors were then interpreted as barriers to and facilitators of successful app-based treatment. RESULTS: Four interrelated themes were identified as affecting the app based treatment effect: adherence, personal factors, app factors, and awareness. Qualitative analyses of the relationships between the themes showed that adherence-related factors directly influenced treatment effect in both a positive and negative matter. In turn, adherence was also positively and negatively influenced by the other 3 themes. Additionally, awareness was positively influenced by the treatment effect. Within these themes, several factors were identified that acted as barriers (eg, unrealistic expectation of time investment and interfering personal circumstances), facilitators (eg, strict integration of exercises and prior pelvic floor muscle therapy), or both (eg, personality traits and increased awareness of symptoms). CONCLUSIONS: This study shows that the effect of app-based treatment for urinary incontinence is mainly influenced by adherence, which in turn is affected by personal factors, app-based factors, and awareness. The identified factors could function as both facilitators and barriers depending on the user and interaction with other themes. Insight into these facilitators and barriers could lead to improved implementation and increased treatment effectiveness by targeting women most likely to benefit and through further development of the app. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.1002/nau.2350

    Letter from the Citizens of Ommen to the Governor of Overijssel

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    Sixteen citizens of Ommen sent a communication to the Governor of the Province that they saw no need for him to send a military detachment to Ommen now that the disturbances had ended. Besides, a relatively few people were the troublemakers. The billeting of military people will be a great burden to the citizens of Ommen.https://digitalcommons.hope.edu/vrp_1830s/1048/thumbnail.jp

    Antihypertensive drug concentration measurement combined with personalized feedback in resistant hypertension:a randomized controlled trial

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    Background:Adherence to antihypertensive drugs (AHDs) is crucial for controlling blood pressure (BP). We aimed to determine the effectiveness of measuring AHD concentrations using a dried blood spot (DBS) sampling method to identify nonadherence, combined with personalized feedback, in reducing resistant hypertension.Methods:We conducted a multicenter, randomized, controlled trial (RHYME-RCT, ICTRP NTR6914) in patients with established resistant hypertension. Patients were randomized to receive either an intervention with standard of care (SoC) or SoC alone. SoC consisted of BP measurement and DBS sampling at baseline, 3 months (t3), 6 months (t6), and 12 months (t12); AHD concentrations were measured but not reported in this arm. In the intervention arm, results on AHD concentrations were discussed during a personalized feedback conversation at baseline and t3. Study endpoints included the proportion of patients with RH and AHD adherence at t12.Results:Forty-nine patients were randomized to receive the intervention+SoC, and 51 were randomized to receive SoC alone. The proportion of adherent patients improved from 70.0 to 92.5% in the intervention+SoC arm (P = 0.008, n = 40) and remained the same in the SoC arm (71.4%, n = 42). The difference in adherence between the arms was statistically significant (P = 0.014). The prevalence of resistant hypertension decreased to 75.0% in the intervention+SoC arm (P &lt; 0.001, n = 40) and 59.5% in the SoC arm (P &lt; 0.001, n = 42) at t12; the difference between the arms was statistically nonsignificant (P = 0.14).Conclusion:Personalized feedback conversations based on DBS-derived AHD concentrations improved AHD adherence but did not reduce the prevalence of RH.</p

    Search for a Standard Model Higgs boson in the mass range 200-600 GeV in the H→ZZ→ℓ+ℓ−qq¯ decay channel with the ATLAS detector

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    A search for a heavy Standard Model Higgs boson decaying via H→ZZ→ℓ+ℓ−qq¯, where ℓ=e or μ, is presented. The search uses a data set of pp collisions at √s =7 TeV, corresponding to an integrated luminosity of 4.7 fb−1 collected in 2011 by the ATLAS detector at the CERN LHC. No significant excess of events above the estimated background is found. Upper limits at 95% confidence level on the production cross section of a Higgs boson with a mass in the range between 200 and 600 GeV are derived. A Standard Model Higgs boson with a mass in the range 300 GeV≤mH ≤ 322 GeV or 353 GeV ≤mH ≤ 410 GeV is excluded at 95% CL. The corresponding expected exclusion range is 351 GeV ≤mH ≤ 404 GeV at 95% CL

    Divergent selection for reproduction affects dag score, breech wrinkle score and crutching time in Merinos

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    Merino lines that were divergently selected from the same base population from 1986 to 2009 for their ability to rear multiples were assessed for dag score in autumn and spring, breech wrinkle score, and crutching time. Animals in the Low (L) line had higher dag and breech wrinkle scores and took longer to be crutched than High (H) line contemporaries. Expressed relative to H line least squares means, means of L line individuals were respectively 54%, 65%, 42% and 40% higher for autumn dag score, spring dag score, breech fold score, and crutching time. Gender effects for dag score were inconclusive, as ewe hoggets were more daggy than rams in autumn, with an opposite trend in spring. Shearer (n = 6) also affected crutching times, with an almost twofold difference in mean crutching time from the quickest shearer (27.7 ± 3.1 seconds) to the slowest shearer (49.4 ± 3.7 seconds). The inclusion of dag score and breech wrinkle score as linear covariates in an analysis on crutching time eliminated the effect of selection line. It thus seems that the quicker crutching times of H line animals may be related to line differences for dag score and, to a lesser extent, for breech wrinkle score
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