Impact of epicardial adipose tissue volume upon left ventricular dysfunction in patients with mild-to-moderate aortic stenosis: A post-hoc analysis.

BACKGROUND:Aortic stenosis (AS) may lead to diastolic dysfunction and later on heart failure (HF) with preserved left ventricular ejection fraction (HFpEF) via increased afterload and left-ventricular (LV) hypertrophy. Since epicardial adipose tissue (EAT) is a metabolically active fat depot that is adjacent to the myocardium and can influence cardiomyocytes and LV function via secretion of proinflammatory cytokines, we hypothesized that high amounts of EAT, as assessed by computed tomography (CT), may aggravate the development and severity of LV hypertrophy and diastolic dysfunction in the context of AS. METHODS:We studied 50 patients (mean age 71 ± 9 years; 9 women) in this preliminary study with mild or moderate AS and mild to severe LV diastolic dysfunction (LVDD), diagnosed by echocardiography, who underwent non-contrast cardiac CT and echocardiography. EAT parameters were measured on 2nd generation dual source CT. Conventional two-dimensional echocardiography and Tissue Doppler Imaging (TDI) was performed to assess LV function and to derive myocardial straining parameter. All patients had a preserved LV ejection fraction > 50%. Data was analysed using Pearson's correlation. RESULTS:Only weak correlation was found between EAT volume or density and E/é ratio as LVDD marker (r = -.113 p = .433 and r = .260, p = .068 respectively). Also, EAT volume or density were independent from Global Strain Parameters (r = 0.058 p = .688 and r = -0.207 p = .239). E/é ratio was strongly associated with LVDD (r = .761 p≤0.0001) and Strain Parameters were moderately associated with LV Ejection Fraction (r = -.669 p≤0.001 and r = -.454 P≤0.005). CONCLUSIONS:In this preliminary study in patients with AS, the EAT volume and density as assessed by CT correlated only weakly with LVDD, as expressed by the commonly used E/é ratio, and with LV strain function. Hence, measuring EAT volume and density may neither contribute to the prediction nor upon the severity of LVDD, respectively

Erprobung der Anwendbarkeit von Hochtemperatursupraleitern im Weltraum Abschlussbericht

Within the research project developments of HTS components for the 'High-Temperature-Superconductivity Space Experiments (HTSSE)' as well as additional work towards future HTS projects has been carried out. The miniaturized patch antenna in thin film technology and the compact hydrogen maser resonator as well have been tested and subsequently integrated together with the HTS components from other groups into the HTSSE-I payload. Although in 1993 the launch of the satellite failed. From results obtained in laboratory tests important conclusions with respect to manufacturing technology, film aging and radiation resistance were gained. Within HTSSE-II a demonstrator for a multifrequency multibeam feed array has been developed. A terrestrial version of this demonstrator has been delivered to the NRL where it was already tested. After the decision for the implementation of the HTSSE-II payload on the backside of the ARGOS-satellite the implementation of the antenna turned out to be no more realizable. Despite that decision the work towards a space version of the demonstrator was in consens with the NRL continued. Additionally the concept of multifrequency array systems has been further developed. Finally RF-properties of Josephson-junctions were investigated with respect to potential applications to nonlinear RF-signal-processing. (orig./MM)Im Forschungs-Vorhaben wurden Arbeiten zur Erprobung der HTSL-Technologie im Rahmen des amerikanischen 'High-Temperature-Superconductivity Space Experiments (HTSSE)' und ergaenzende Arbeiten zur Vorbereitung avisierter zukuenftiger Projekte in diesem Anwendungsfeld durchgefuehrt. Die miniaturisierte Patch-Antenne in HTSL-Duennfilmtechnologie und der kompakte Wasserstoffmaser-Resonator mit YBCO-Oberflaechen wurde vom NRL getestet und zusammen mit anderen Komponenten in das Weltraummodul HTSSE I integriert. Obwohl Ende 1993 der Weltraumstart des HTSSE-I-Moduls mit Hilfe einer Titan-Rakete misslang, fuehrten Auswertungen der bis dahin erzielten Testergebnisse zu wichtigen Erkenntnissen bezueglich der Herstellungstechnologie, der Filmalterung und der Strahlungsresistenz. Im Rahmen der HTSSE-II-Mission wurde ein Demonstrator fuer das Speisesystem einer multifrequenten Mehrfachkeulenantenne aus HTSL entwickelt. Ein terrestrischer Demonstrator fuer dieses Konzept wurde 1993 an das NRL ausgeliefert und dort getestet. Nachdem eine Entscheidung zur Implementierung der HTSSE-II-Nutzlast in den erdabgewandten Teil des ARGOS-Satelliten fiel, erwies sich eine Integration dieses Antennen-Demonstrators aus technischen und finanziellen Gruenden als nicht mehr realisierbar. Trotzdem wurden in Absprache und Kooperation mit dem NRL die Arbeiten an diesem Demonstrator fortgesetzt und insbesondere eine weltraumtaugliche Version realisiert. Ergaenzend wurden Arbeiten zur Fortentwicklung der Konzeption von multifrequenten Antennen-Arrays und Arbeiten zur Verwendung verschiedener Josephson-Element-Strukturen fuer die nichtlineare Hochfrequenzsignalverarbeitung durchgefuehrt. (orig./MM)Available from TIB Hannover: F97B79+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany); Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA) GmbH, Bonn (Germany)DEGerman