Velocity vector imaging to quantify left atrial function

The aim of our study was to assess the feasibility of a new image analysis, velocity vector imaging (VVI), in the assessment of left atrial volumes (LAV) and left atrial ejection fraction (LAEF). We retrospectively analysed 100 transthoracic echocardiographic findings in 71 men, and 29 women (mean age 57 ± 19.8 years). Two subgroups of patients were defined: (1) with left ventricular (LV) EF > 50%, and (2) LV EF < 50%. For the VVI method of indexed LAV assessment we used the apical four-chamber view. From the displacement of LA endocardial pixels time–volume curves were extracted which provided automatically data regarding indexed maximum LAV (LAVImax), indexed minimum LAV (LAVImin), and LAEF. LAVs and LAEF by 2-dimensional echocardiograhy (2DE) were measured by Simpson’s biplane disc summation method. Comparing LAVImax, LAVImin, and LAEF by VVI versus 2DE in the total study population, we found significant correlations: r = 0.94, P < 0.0001, r = 0.94, P < 0.0001, r = 0.79, P < 0.0001, respectively. In addition, LAVImax ≥ 40 ml/m2 was 94% sensitive and 72% specific, LAVImin ≥ 27 ml/m2 was 90% sensitive and 86% specific, and LAEF < 30% was 80% sensitive and 96% specific for the detection of LV systolic dysfunction. There were highly significant inverse associations of LAVImax and LAVImin to LVEF. LAEF was also significantly related to LV systolic function. When comparing the time required for VVI and 2DE measurements, VVI led to 62% reduction in the measurement time. In conclusion, VVI is a feasible method for the assessment of LAVs and LAEF. It provides close agreement with that measured by conventional 2DE Simpson’s biplane method with significant time saved

Improving precision for detecting change in the shape of the cornea in patients with keratoconus

To investigate a method for precision analysis to discriminate true corneal change from measurement imprecision in keratoconus (KC). Thirty patients with KC and 30 healthy controls were included. Coefficients of repeatability and limits of agreement (LOA) were compared using multiple measurements for inter-observer and inter-device agreement with the Pentacam HR, Orbscan IIz, and Tomey Casia SS-1000. Correlation of repeated measurements was evaluated using a linear mixed effect model (also called random effect model). A formula was derived for the theoretical expected change in precision and compared with measured change. Correlation between measurements from the same eye was small (R = 0.13). The 99.73% LOA (3 SD) of the mean of three measurements, provided better precision than 95% LOA (2 SD) of single cut-off values as expected from statistical theory for uncorrelated measurements for evidence of a significant change in corneal shape in patients with keratoconus. This enabled the determination of cut-off values for the detection of true change in corneal shape. The mean of three repeated measurements will provide better precision when there is minimal correlation. Three (rather than two) standard deviations provides a precise estimate of the LOA within or between observers and can be used as a reliable measure for identifying stage-independent corneal shape changes (progression) in keratoconus

Importance of including soil moisture in drought monitoring over the Brazilian semiarid region: An evaluation using the JULES model, in situ observations, and remote sensing

Soil moisture information is essential to monitoring of the intensity of droughts, the start of the rainy season, planting dates and early warnings of yield losses. We assess spatial and temporal trends of drought over the Brazilian semiarid region by combining soil moisture observations from 360 stations, root zone soil moisture from a leading land surface model, and a vegetation health index from remote sensing. The soil moisture dataset was obtained from the network of stations maintained by the National Center of Monitoring and Early Warning of Natural Disasters (Cemaden), in Brazil. Soil water content at 10 to 35 cm depth, for the period 1979–2018, was obtained from running the JULES land surface model (the Joint UK Land Environment Simulator). The modelled soil moisture was correlated with measurements in the common period of 2015–2018, resulting in an average correlation coefficient of 0.48 across the domain. The standardized soil moisture anomaly (SMA) was calculated for the long-term modelled soil moisture and revealed strong negative values during well-known drought periods in the region, especially during El-Niño years. The performance of SMA in identifying droughts during the first 2 months of the raining and cropping season was similar to the Standardized Precipitation Index (SPI), commonly used for drought assessment: 12–14 events were identified by both indices. Finally, the temporal relationship between both SMA and SPI with the Vegetation Health Index (VHI) was assessed using the cross-wavelet transform. The results indicated lagged correlations of 1 to 1.5 months in the annual scale, suggesting that negative trends in SMA and SPI can be an early warning to yield losses during the growing season. Public policies on drought assessment should consider the combination of multiple drought indices, including soil moisture anomaly

Gender specific age-related changes in bone density, muscle strength and functional performance in the elderly: a-10 year prospective population-based study

Background:&nbsp;Age-related losses in bone mineral density (BMD), muscle strength, balance, and gait have been linked to&nbsp;an increased risk of falls, fractures and disability, but few prospective studies have compared the timing, rate and pattern&nbsp;of changes in each of these measures in middle-aged and older men and women. This is important so that targeted&nbsp;strategies can be developed to optimise specific musculoskeletal and functional performance measures in older adults.&nbsp;Thus, the aim of this 10-year prospective study was to: 1) characterize and compare age- and gender-specific changes in&nbsp;BMD, grip strength, balance and gait in adults aged 50 years and over, and 2) compare the relative rates of changes&nbsp;between each of these musculoskeletal and functional parameters with ageing.Methods: Men (n = 152) and women (n = 206) aged 50, 60, 70 and 80 years recruited for a population-based study had&nbsp;forearm BMD, grip strength, balance and gait velocity re-assessed after 10-years.Results: The annual loss in BMD was 0.5-0.7% greater in women compared to men aged 60 years and older&nbsp;(p &lt; 0.05- &lt; 0.001), but there were no gender differences in the rate of loss in grip strength, balance or gait. From the age&nbsp;of 50 years there was a consistent pattern of loss in grip strength, while the greatest deterioration in balance and gait&nbsp;occurred from 60 and 70 years onwards, respectively. Comparison of the changes between the different measures&nbsp;revealed that the annual loss in grip strength in men and women aged &lt;70 years was 1-3% greater than the decline in&nbsp;BMD, balance and gait velocity.Conclusion: There were no gender differences in the timing (age) and rate (magnitude) of decline in grip strength,&nbsp;balance or gait in Swedish adults aged 50 years and older, but forearm BMD decreased at a greater rate in women than&nbsp;in men. Furthermore, there was heterogeneity in the rate of loss between the different musculoskeletal and function&nbsp;parameters, especially prior to the age of 70 years, with grip strength deteriorating at a greater rate than BMD,&nbsp;balance and gait.</div

Heart Rate Variability and Atria Function in Children at Late Follow-Up Evaluation After Atrioventricular Node Slow-Pathway Radiofrequency Ablation

This study was designed to assess the changes in the conductive system, autonomic dysfunction, and global and regional function of the atria and ventricles in children late after slow-pathway radiofrequency ablation (RFA). The study enrolled 22 children, who has successfully undergone RFA 2 to 5 years previously (RFA group) and 20 healthy children (control group). Electrophysiologic study was performed for the RFA group. Holter monitoring and echocardiography were performed for all the children. At a late follow-up assessment, the RFA children were free of paroxysms, whereas 8 of the 22 children (36%) reported transient palpitations. Both mean and maximal heart rates (HR) were significantly increased, whereas indices of HR variability (% of succesive normal sinus RR intervals exceeding 50 ms [pNN50], root mean square of the succesive normal sinus RR interval difference [rMSSD], high-frequency component [HFC]) were significantly decreased in the RFA group compared with preablation and control data. Left atrial (LA) and right atrial (RA) volumes were significantly higher, and atria deformation indices were significantly lower in the RFA group. Correlations were found between the mean HR and the volumes of LA (r = 0.477; p < 0.001) and RA (r = 0.512; p < 0.001). A negative correlation between the maximal LA volume and the longitudinal strain rate (SR) during relaxation (r = –0.476; p = 0.03) and a positive correlation between the minimal LA volume and both longitudinal SR (r = 0.361; p = 0.03) and strain (ε) (r = 0.375; p = 0.024) during contraction were shown. These data suggest a possible link between atrial dysfunction and the hyperadrenergic state after RFA