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Purpose
The aim of the current study was to evaluate the feasibility of phase analysis on gated myocardial perfusion SPECT (GMPS) for the assessment of left ventricular (LV) diastolic dyssynchrony in a head-to-head comparison with tissue Doppler imaging (TDI).Methods
The population consisted of patients with end-stage heart failure of New York Heart Association functional class III or IV with a reduced LV ejection fraction of ??35%. LV diastolic dyssynchrony was calculated using TDI as the maximal time delay between early peak diastolic velocities of two opposing left ventricle walls (diastolic mechanical delay). Significant LV diastolic dyssynchrony was defined as a diastolic mechanical delay of >55?ms on TDI. Furthermore, phase analysis on GMPS was performed to evaluate LV diastolic dyssynchrony; diastolic phase standard deviation (SD) and histogram bandwidth (HBW) were used as markers of LV diastolic dyssynchrony.Results
A total of 150 patients (114 men, mean age 66.0?±?10.4?years) with end-stage heart failure were enrolled. Both diastolic phase SD (r?=?0.81, p?0.01) and diastolic HBW (r?=?0.75, p?0.01) showed good correlations with LV diastolic dyssynchrony on TDI. Additionally, patients with LV diastolic dyssynchrony on TDI (>55?ms) showed significantly larger diastolic phase SD (68.1?±?13.4° vs. 40.7?±?14.0°, p?0.01) and diastolic HBW (230.6?±?54.3° vs. 129.0?±?55.6°, p?0.01) as compared to patients without LV diastolic dyssynchrony on TDI (??55?ms). Finally, phase analysis on GMPS showed a good intra- and interobserver reproducibility for the determination of diastolic phase SD (ICC 0.97 and 0.88) and diastolic HBW (ICC 0.98 and 0.93).Conclusion
Phase analysis on GMPS showed good correlations with TDI for the assessment of LV diastolic dyssynchrony. 相似文献Introduction
Few studies have measured gender inequality at levels lower than the country. We sought to develop neighbourhood indicators of gender inequality, and assess their ability to capture variability in gender inequality across Québec, Canada. 相似文献Materials and Methods: The first tier of testing utilized the Organization for Economic Co-operation and Development (OECD) QSAR Toolbox to perform an in silico evaluation of the skin irritation potential of the product ingredients, and the second tier of testing utilized an OECD in vitro guideline test to evaluate the skin irritation potential of each product.
Results: Thirty-two ingredients were evaluated using the OECD QSAR Toolbox profiler for the tier one analysis; nine ingredients received a structural alert for skin irritation/corrosion. In the tier two in vitro analysis, the evaluated cleansing conditioner products were all classified as non-irritants.
Conclusions: These results provide evidence that use of the evaluated commercially available cleansing conditioners would not be expected to cause skin irritation among consumers. Additionally, this study demonstrates that the presence of structural alerts does not always accurately predict the safety of a product, as focused tier-based testing is necessary to comprehensively evaluate a product. This study illustrates a tier-based safety assessment approach, applicable to a wide variety of health endpoints, which efficiently and adequately evaluates the safety of personal care and cosmetic products and their ingredients. 相似文献