473 research outputs found

    Doppler tissue imaging in ST-elevation myocardial infarction

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    Highly available, noninvasive and cost-effective, echocardiography remains a keystone in the evaluation of patients with coronary artery disease (CAD). Echocardiographic assessment of cardiac function at rest and during dobutamine stress has direct clinical implications. Conventional echocardiographic parameters however, are partly based on visual interpretation of cardiac motion, thereby subject to interobserver variability, especially in patients with poor image quality. As a complement, myocardial velocity imaging techniques such as Doppler tissue imaging (DTI) offer quantitative markers of cardiac function. In the present study, we explored the feasibility and diagnostic value of DTI in the evaluation of left and right ventricular function, the presence of inducible ischemia and myocardial viability in patients with ST-elevation myocardial infarction (STEMI). In 90 patients with STEMI (64 men and 26 women aged 65±13 years) echocardiography was performed at day 1, 5–7 days and 6 months after admission. At day 5–7, dobutamine stress echocardiography (DSE) with wall motion analysis (WMA) was performed, followed by coronary angiography within 24 hours. Using DTI, systolic, early and late diastolic myocardial velocities were recorded near the mitral annulus at 4 left ventricular (LV) sites, and near the tricuspid annulus in the right ventricular free wall. The myocardial performance index (MPI), a Doppler-based, combined measure of systolic and diastolic function, was calculated as the sum of the isovolumic time intervals divided by the ejection time derived from DTI at the 4 LV sites. Forty-one aged-matched healthy subjects served as controls. In patients with complete normalization of conventional parameters of LV function at follow-up, peak systolic as well as early diastolic LV myocardial velocities were significantly reduced compared with those in healthy subjects, possibly reflecting a residual subendocardial damage. Using peak systolic velocity in the right ventricular (RV) free wall as a marker of RV function, sensitivity and specificity of DTI in identifying patients with electrocardographic signs of RV infarction (ST-elevation in ECG lead V4R) were 89% and 71%, respectively. Furthermore, peak RV systolic velocities remained reduced in patients with RV infarction, even after resolution of ECG changes and were still evident at 6 months’ follow-up. Use of the MPI as a marker of ischemia during DSE was shown to be feasible, and although the majority of patients did not achieve an optimal level of stress, relative changes in MPI between rest and peak stress offered reasonable diagnostic properties, superior to those of WMA. Sensitivity and specificity for detection of left anterior descending, left circumflex and right coronary artery disease were 80% and 87%, 59% and 80% and 85% and 72%, respectively. Finally, we found that MPI during low-dose dobutamine infusion exhibits a specific pattern, similar to that of WMA, predicting late recovery of LV systolic function. In conclusion, the use of DTI during echocardiography at rest and during dobutamine stress is feasible and allows evaluation of LV and RV function in the acute as well as the late phase after a STEMI. Furthermore, changes in MPI derived from DTI during DSE identify patients with residual CAD and predict late recovery of LV function, independently of age, troponin level and time to reperfusion treatment

    Aufbau einer Korpusinfrastruktur für die Beobachtung des Schreibgebrauchs

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    A single abstract from the DHd-2016 Book of Abstracts.Sofern eine editorische Arbeit an dieser Publikation stattgefunden hat, dann bestand diese aus der Eliminierung von Bindestrichen in Überschriften, die aufgrund fehlerhafter Silbentrennung entstanden sind, der Vereinheitlichung von Namen der Autor*innen in das Schema "Nachname, Vorname" und/oder der Trennung von Überschrift und Unterüberschrift durch die Setzung eines Punktes, sofern notwendig

    How healthy are chronically ill patients after eight years of homeopathic treatment? – Results from a long term observational study

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    <p>Abstract</p> <p>Background</p> <p>Homeopathy is a highly debated but often used medical treatment. With this cohort study we aimed to evaluate health status changes under homeopathic treatment in routine care. Here we extend former results, now presenting data of an 8-year follow-up.</p> <p>Methods</p> <p>In a prospective, multicentre cohort study with 103 homeopathic primary care practices in Germany and Switzerland, data from all patients (age >1 year) consulting the physician for the first time were observed. The main outcome measures were: The patients' perceived change in complaint severity (numeric rating scales from 0 = no complaint to 10 = maximal severity) and quality of life as measured by the SF-36 at baseline, and after 2 and 8 years.</p> <p>Results</p> <p>A total of 3,709 patients were studied, 73% (2,722 adults, 72.8% female, age at baseline 41.0 ± 12.3; 819 children, 48.4% female, age 6.5 ± 4.0) contributed data to the 8-year follow-up. The most frequent diagnoses were allergic rhinitis and headache in adults, and atopic dermatitis and multiple recurrent infections in children. Disease severity decreased significantly (p < 0.001) between baseline, 2 and 8 years (adults from 6.2 ± 1.7 to 2.9 ± 2.2 and 2.7 ± 2.1; children from 6.1 ± 1.8 to 2.1 ± 2.0 and 1.7 ± 1.9). Physical and mental quality of life sores also increased considerably. Younger age, female gender and more severe disease at baseline were factors predictive of better therapeutic success.</p> <p>Conclusion</p> <p>Patients who seek homeopathic treatment are likely to improve considerably. These effects persist for as long as 8 years.</p

    Low impact of regular PCR testing on presence at work site during the COVID-19 pandemic: experiences during an open observational study in Lower Saxony 2020-21

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    Background: Since social distancing during the COVID-19-pandemic had a profound impact on professional life, this study investigated the effect of PCR testing on on-site work. Methods: PCR screening, antibody testing, and questionnaires offered to 4,890 working adults in Lower Saxony were accompanied by data collection on demographics, family status, comorbidities, social situation, health-related behavior, and the number of work-related contacts. Relative risks (RR) with 95 % confidence intervals were estimated for the associations between regular PCR testing and other work and health-related variables, respectively, and working on-site. Analyses were stratified by the suitability of work tasks for mobile office. Results: Between April 2020 and February 2021, 1,643 employees underwent PCR testing. Whether mobile working was possible strongly influenced the work behavior. Persons whose work was suitable for mobile office (mobile workers) had a lower probability of working on-site than persons whose work was not suitable for mobile office (RR = 0.09 (95 % CI: 0.07 – 0.12)). In mobile workers, regular PCR-testing was slightly associated with working on-site (RR = 1.19 (0.66; 2.14)). In those whose working place was unsuitable for mobile office, the corresponding RR was 0.94 (0.80; 1.09). Compared to persons without chronic diseases, chronically ill persons worked less often on-site if their workplace was suitable for mobile office (RR = 0.73 (0.40; 1.33)), but even more often if their workplace was not suitable for mobile office (RR = 1.17 (1.04; 1.33)). Conclusion: If work was suitable for mobile office, regular PCR-testing did not have a strong effect on presence at the work site. Trial registration: An ethics vote of the responsible medical association (Lower Saxony, Germany) retrospectively approved the evaluation of the collected subject data in a pseudonymized form in the context of medical studies (No. Bo/30/2020; Bo/31/2020; Bo/32/2020)

    Continuum of vasodilator stress from rest to contrast medium to adenosine hyperemia for fractional flow reserve assessment

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    Objectives: This study compared the diagnostic performance with adenosine-derived fractional flow reserve (FFR) ≤0.8 of contrast-based FFR (cFFR), resting distal pressure (Pd)/aortic pressure (Pa), and the instantaneous wave-free ratio (iFR). Background: FFR objectively identifies lesions that benefit from medical therapy versus revascularization. However, FFR requires maximal vasodilation, usually achieved with adenosine. Radiographic contrast injection causes submaximal coronary hyperemia. Therefore, intracoronary contrast could provide an easy and inexpensive tool for predicting FFR. Methods: We recruited patients undergoing routine FFR assessment and made paired, repeated measurements of all physiology metrics (Pd/Pa, iFR, cFFR, and FFR). Contrast medium and dose were per local practice, as was the dose of intracoronary adenosine. Operators were encouraged to perform both intracoronary and intravenous adenosine assessments and a final drift check to assess wire calibration. A central core lab analyzed blinded pressure tracings in a standardized fashion. Results: A total of 763 subjects were enrolled from 12 international centers. Contrast volume was 8 ± 2 ml per measurement, and 8 different contrast media were used. Repeated measurements of each metric showed a bias &lt;0.005, but a lower SD (less variability) for cFFR than resting indexes. Although Pd/Pa and iFR demonstrated equivalent performance against FFR ≤0.8 (78.5% vs. 79.9% accuracy; p = 0.78; area under the receiver-operating characteristic curve: 0.875 vs. 0.881; p = 0.35), cFFR improved both metrics (85.8% accuracy and 0.930 area; p &lt; 0.001 for each) with an optimal binary threshold of 0.83. A hybrid decision-making strategy using cFFR required adenosine less often than when based on either Pd/Pa or iFR. Conclusions: cFFR provides diagnostic performance superior to that of Pd/Pa or iFR for predicting FFR. For clinical scenarios or health care systems in which adenosine is contraindicated or prohibitively expensive, cFFR offers a universal technique to simplify invasive coronary physiological assessments. Yet FFR remains the reference standard for diagnostic certainty as even cFFR reached only ∼85% agreement

    Laser powder bed fusion of Cu-Ti-Zr-Ni bulk metallic glasses in the Vit101 alloy system

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    Laser powder bed fusion (PBF-LB/M) of bulk metallic glasses (BMGs) has experienced growing scientific and industrial interest in the last years, with a special focus on application relevant systems based on zirconium. The high cooling rates and the layer-wise build-up process allow overcoming size and geometry limitations typical for conventional casting routes. Yet, the novel production approach requires different alloy characteristics than casting processes. The present work reports for the first time on the PBF-LB/M-processing of three CuTi-based bulk metallic glass formers in the Vit101 system, allowing to exceed the mechanical performance of most additively formed Zr-based BMGs. Furthermore, the influence of alloy properties like thermal stability and toughness on the PBF-LB/M applicability are systematically studied. Thermal stability plays a minor role to produce amorphous specimen, while notch toughness is found to be a more crucial aspect to achieve parts with low defect density and resulting high mechanical performance. The results suggest fundamentally different alloy development strategies adapted to the needs of the PBF-LB/M-process, leaving classical casting-based optimization of glass forming ability behind and evolving towards a rather toughness-oriented optimization

    Mobile SARS‑CoV‑2 screening facilities for rapid deployment and university-based diagnostic laboratory

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    The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has created a public crisis. Many medical and public institutions and businesses went into isolation in response to the pandemic. Because SARS-CoV-2 can spread irrespective of a patient's course of disease, these institutions’ continued operation or reopening based on the assessment and control of virus spread can be supported by targeted population screening. For this purpose, virus testing in the form of polymerase chain reaction (PCR) analysis and antibody detection in blood can be central. Mobile SARS-CoV-2 screening facilities with a built-in biosafety level (BSL)-2 laboratory were set up to allow the testing offer to be brought close to the subject group's workplace. University staff members, their expertise, and already available equipment were used to implement and operate the screening facilities and a certified diagnostic laboratory. This operation also included specimen collection, transport, PCR and antibody analysis, and informing subjects as well as public health departments. Screening facilities were established at different locations such as educational institutions, nursing homes, and companies providing critical supply chains for health care. Less than 4 weeks after the first imposed lockdown in Germany, a first mobile testing station was established featuring a build-in laboratory with two similar stations commencing operation until June 2020. During the 15-month project period, approximately 33,000 PCR tests and close to 7000 antibody detection tests were collected and analyzed. The presented approach describes the required procedures that enabled the screening facilities and laboratories to collect and process several hundred specimens each day under difficult conditions. This report can assist others in establishing similar setups for pandemic scenarios

    Agreement of the resting distal to aortic coronary pressure with the instantaneous wave-free ratio

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    Background: Recently, 2 randomized controlled trials showed that the instantaneous wave-free ratio (iFR), a resting coronary physiological index, is noninferior to fractional flow reserve for guiding revascularization. The resting distal to aortic coronary pressure (Pd/Pa) measured at rest is another adenosine-free index widely available in the cardiac catheterization laboratory; however, little is known about the agreement of Pd/Pa using iFR as a reference standard. Objectives: The goal of this study was to investigate the agreement of Pd/Pa with iFR. Methods: A total of 763 patients were prospectively enrolled from 12 institutions. iFR and Pd/Pa were measured under resting conditions. Using iFR ≤0.89 as a reference standard, the agreement of Pd/Pa and its best cutoff value were assessed. Results: According to the independent core laboratory analysis, iFR and Pd/Pa were analyzable in 627 and 733 patients (82.2% vs. 96.1%; p &lt; 0.001), respectively. The median iFR and Pd/Pa were 0.90 (interquartile range: 0.85 to 0.94) and 0.92 (interquartile range: 0.88 to 0.95), and the 2 indices were highly correlated (R2 = 0.93; p &lt; 0.001; iFR = 1.31 * Pd/Pa –0.31). According to the receiver-operating characteristic curve analysis, Pd/Pa showed excellent agreement (area under the curve: 0.98; 95% confidence interval: 0.97 to 0.99; p &lt; 0.001) with a best cutoff value of Pd/Pa ≤0.91. The diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were 93.0%, 91.4%, 94.4%, 93.3%, and 92.7%, respectively. These results were similar in patients with acute coronary syndrome and stable angina. Conclusions: Pd/Pa was analyzable in a significantly higher number of patients than iFR. Pd/Pa showed excellent agreement with iFR, suggesting that it could be applied clinically in a similar fashion. (Can Contrast Injection Better Approximate FFR Compared to Pure Resting Physiology? [CONTRAST]; NCT02184117)
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