Left atrial (LA) distension has been demonstrated to be linked with aortic stiffness in different patient populations. Three-dimensional (3D) speckle-tracking echocardiography (STE) seems to be a promising tool for volumetric and functional evaluation of the LA. The aim of the present study was to determine whether correlations exist between 3DSTE-derived LA volume-based and strain parameters characterizing all phasic functions of the LA and echocardiographic aortic elastic properties in healthy subjects. The study included 19 healthy volunteers (mean age: 37.9 ± 11.4 years, 11 men) who had undergone complete two-dimensional (2D) Doppler transthoracic echocardiography extended with the assessment of aortic elastic properties and 3DSTE. Results: None of LA volumes correlated with echocardiographic aortic elastic properties. Active atrial stroke volume correlated with aortic stiffness index (ASI, r = 0.45, p = 0.05). None of other volume-based functional properties signifcantly correlated with aortic stiffness parameters. Global peak 3D strain correlated with aortic strain (r = ‒0.46, p = 0.05). global radial pre-atrial contraction strain correlated with ASI (r = ‒0.49, p = 0.04) and AS (r = ‒0.50, p = 0.04). Conclusions: Correlations exist between 3DSTE-derived LA functional parameters and eschocardiographic aortic elastic properties in healthy subjects.
Myocardial contractility of the left ventricle (LV) is related to arterial distensibility. Sport activity is frequently associated with changes in both LV and arterial functions. This study aimed to find correlations between three-dimensional speckle-tracking echocardiography-derived segmental LV deformation parameters and echocardiographically assessed aortic stiffness index (ASI) in athletes. This study comprised 26 young elite athletes (mean age: 26.7 ± 8.4 years, nine men).
Among segmental circumferential strains (CSs), only that of apical anterior (r = 0.40, p = 0.05), septal (r = 0.47, p = 0.01), inferior (r = 0.59, p = 0.001), lateral (r = 0.44, p < 0.05), and midventricular anteroseptal (r = 0.44, p < 0.05) segments correlated with ASI, whereas LV-CS of the midventricular anterior segment showed a correlation tendency. Only longitudinal strain of basal anteroseptal (r = −0.46, p < 0.05) and inferoseptal (r = −0.57, p < 0.01) segments showed correlations with ASI, whereas that of the basal anterior segment had only a tendency to correlate. Some segmental multidirectional strains also correlated with ASI.
Correlations could be demonstrated between increased aortic stiffness and circular function of the apical and midventricular LV fibers and longitudinal motion of the basal septum and LV anterior wall (part of LV outflow tract) in maintaining circulation in the elite athletes.
Tissue level myocardial perfusion is one of the most important prognostic factors after successful recanalisation of the occluded coronary artery in patients suffering acute ST elevation myocardial infarction (STEMI). The primary objective of the present study was to examine the relationship between videodensitometric myocardial perfusion parameters as assessed on coronary angiograms directly following successful recanalization therapy and magnetic resonance imaging (MRI)-derived myocardial tissue loss late after STEMI. The study comprised 29 STEMI patients. Videodensitometric parameter Gmax/Tmax was calculated to characterize myocardial perfusion, derived from the plateau of grey-level intensity (Gmax), divided by the time-to-peak intensity (Tmax). Myocardial loss index (MLI) was assessed by cardiac MRI following 376 ± 254 days after PCI. Results: Signifcant correlations could be demonstrated between MLI and Gmax (r = 0.36, p = 0.05) and Gmax/Tmax (r = 0.40, p = 0.03) using vessel masking. Using receiver operating characteristic curve analysis, Gmax/Tmax < 2.17 predicted best MLI = 0.3, 0.4, 0.5 and 0.6 with good sensitivity and specifcity data, while Gmax/Tmax < 3.25 proved to have a prognostic role in the prediction of MLI = 0.7. Conclusions: Selective myocardial tissue level perfusion quantitative measurement method is feasible and can serve as a good predictor of myocardial tissue loss following STEMI and revascularization therapy.
The chemistry of technetium is being explored at the University of Nevada Las Vegas. Our goal is to investigate both the applied
and fundamental aspects of technetium chemistry, with a special emphasis on synthesis, separations, and materials science.
The synthetic chemistry focuses on metal–metal multiple bonding, oxides and halides. Synthesis and characterizations of (n-Bu4N)2Tc2X8, Tc2(O2CCH3)4X2 (X = Cl, Br), TcO2, Bi2Tc2O7, Bi3TcO8, TcBr3 and TcBr4 have been performed. The applied chemistry is related to the behavior of Tc in the UREX process. Separation of U/Tc has been
conducted using anion exchange resin and metallic Tc waste form synthesized and characterized.