3D strain parameters are highly accurate in identifying global left ventricular systolic dysfunction in ischemic heart disease

Background: Although being considered a robust measure of left ventricular (LV) systolic function, global longitudinal 2D strain (LS) had weak correlations with LVEF in ischemic heart disease. We studied the relationship of 3D strain parameters with 3D LVEF and their predictive value for identifying LV dysfunction (i.e. LVEF,55%). Methods and results: 40 pts with documented coronary artery disease (age 60+14, 31 men, 3D LVEF=50+13%, range 19-69%) underwent 3D echo with Vivid E9 (GE, Horten, N). Global peak values of LS, circumferential (CS), radial (RS) and areastrain (AS) were computed with EchoPac BT 11 in 38 pts (23 had LVEF ,55%). All 3D strains were closely correlated with EF (r=-0.88 for AS, r=-0.86 for LS, CS, r=0.86 for RS, p,0.001 for all). All strains had an excellent accuracy to identify a LVEF ,55% (Table 1, Figure 1). Conclusions: In ischemic pts with wide range of LVEF, all 3D strain indexes showed a close correlation with LVEF and a good predictive power to identify LV dysfunction. Global CS had the best discriminative power to identify a 3D LVEF,55%. These findings probably reflect the ability of 3D speckle-tracking to fully capture the complex LV deformation in ischemic heart disease

Global 3D circumferential strain is related to infarct size and transmural extent of myocardial necrosis in patients with successfully reperfused STEMI

Infarct size represents a powerful predictor of mortality and adverse events. The ability of 3D speckle-tracking to estimate infarct size in STEMI was not explored. Methods: 49 pts (age 60+15) with a first recent STEMI (8+3 days) successfully reperfused by primary PCI were studied. Peak global 2D longitudinal strain (LS) from 3 apical views (68+9 fps) and 3D LS, circumferential (CS), radial (RS) and area strain (AS) from 4-beat LV data sets (30+3 vps) were measured. Infarct size was estimated by peak cTnI levels in all pts. In 27 pts, delayed-enhancement MRI (DE-MRI) was performed within 24h from echo study. Transmural extent of necrosis (% DE) was measured and infarct size index (ISI, %) was calculated as the sum of %DE for all LV segments divided by 17. Results: Peak cTnI (mean 162 mg/L, range 2.0-916) was correlated with 2D LS and all 3D strains, as well as with 3D LV volumes and ejection fraction (Table). At multivariable analysis, only CS emerged as significant independent predictor of infarct size (b 0.584, p,0.001). In MRI pts, CS showed the closest correlation with ISI among all strains (r=0.716, p,0.001) and the best discriminative power to predict the extent of necrosis transmurality at DE-MRI (F ANOVA 82.1, p,0.0001). In 20 pts, intraclass correlation coefficient for 3D CS was 0.98 for intra- and 0.95 for interobserver reproducibility. Conclusion. In STEMI pts, 3D CS showed good reproducibility and accuracy for infarct size estimation in comparison with DE-MRI and cTnI, being superior than 2D and 3D LS. This is the first study demonstrating that 3D CS may be used as an objective marker of infarct size and necrosis transmurality at bedside

Single-plane and biplane 2D algorithms and non-atrial specific 3D echo softwares underestimate left atrial volumes in comparison with specific 3D echo software tailored for left atrium

Background: Left atrial (LA) volumes are well-known predictors of cardiovascular outcome in a variety of heart diseases. However, LA is a 3D asymmetric structure and its volume calculations using 2D echo methods may be hampered by geometrical assumptions about its shape, acquisition of foreshortened or off-axis LA views. To partially overcome these limitations 3D echo has been used, but no 3D software specifically tailored for the LA quantitation has been available until recently. We sought to assess the influence of the echo technique and the algorithm used on LA volume measurement. Methods and results: 58 healthy volunteers aged 18 to 65 (38+12 years, 31 women) with good acoustic window, underwent acquisition of 2D apical 4- and 2-chamber views for the assessment of the LA and a 3D full-volume data set from apical approach (31+6 vps) for LA quantitation. LA volumes were calculated on 2D images using both single- and bi-plane disc summation algorithms. 3D LA data sets were quantitated using a software developed for the left ventricle (4D AutoLVQ, GE Healthcare, Horten N) and adapted to LA volume measurements, as well as with a novel semi-automatic software tailored for LA quantitation developed by TomTec (Unterschleissheim,Germany). Comparison of LA maximal and minimal volumes obtained using the 4 algorithms are summarized in the Table. Conclusions: In comparison to LA volumes obtained using a 3D software dedicated for LA analysis, both 2D algorithms and the non-atrial specific 3D software underestimate significantly LA volumes. Whether the implementation of atrial-specific 3D softwares could improve the prognostic stratification of patients with LA enlargement in various conditions remains to be verified

Reference ranges for the various components of left ventricular myocardial deformation assessed by 3D speckle-tracking, and comparison with 2D speckle-tracking

Background: Speckle-tracking echocardiography (STE) enables the study of myocardial deformation and thus can provide insights about heart structure and function. However, 2D STE suffers from errors due to through-plane decorrelation. 3D STE overcomes such limitation, yet data regarding normality ranges for this new technology are lacking. Accordingly, we sought to assess the reference values of a newly developed 3D speckle-tracking method for longitudinal (L1), circumferential (C1), area (A1) and radial strain (R1), and then to compare them with those obtained by 2D STE. Methods: We acquired 3D full-volume data sets (32+2 vps) from apical approach in 78 healthy volunteers (37+11 years, 40 women) using Vivid E9 equipped with 4V probe (GE Healthcare, Horten, N) to measure the different components of LV deformation in 17 segments. 2D L1 was assessed in apical 4-, 3-, and 2-chamber views (76+6 fps) and C1 was measured in parasternal short-axis views (73+7 fps) during the same echo study. Results: Total study time was shorter with 3D than with 2D STE (5.1+1.1 vs 7.0+1.2 minutes; p, 0.001), due to shorter acquisition time (2+0.6 vs 4+2 minutes; p,0.001). Conversely, analysis time was similar for 3D and 2D STE (3.3+0.8 vs 3.0+0.8 minutes; p=NS). 3D L1 (-20%, 95%CI -19 to -21%) was significantly lower than 2D L1 (-21%, 95%CI -21 to -22%, p=0.0001). Global 3D C1 (-19%, 95%CI -19 to -20%) was higher than 2D C1 at basal level (-18%, 95%CI -17 to -19%, p=0.002), lower than 2D C1 at apical level (-30%, 95%CI -29 to -34%, p,0.0001), but similar to 2D C1 at mid-papillary level (-19%, 95%CI -17 to -21%, p=NS). 3D values for A1 and R1 were (-35%, 95%CI -36 to -34%, and 57%, 95%CI 55 to 59%, respectively). Reproducibility for the 3D strain components assessed in 20 subjects and expressed as mean difference of repeated measurements was: 0.5% and 1.5% for L1, 0.5 and 1.4% for C1, 0.6 and 2.1% for A1, 1.4 and 3.1% for R1, for intra- and inter-observer reproducibility, respectively. Conclusions: 3D STE is a simple, fast and reproducible technique for assessing the different components of LV myocardial deformation. Due to the reported inconsistency of LV strain values among different vendors, it is pivotal to establish vendor-specific reference values for this newly developed echo tehnique

Determinantes biológicos e sócio-culturais associados à prática de atividade física de adolescentes Biological and socio-cultural determinants of physical activity in adolescents

A atividade física é um comportamento importante na promoção de saúde e na prevenção de doenças. Para que se desenvolvam programas eficazes no incentivo à prática de atividade física em adolescentes, torna-se necessário que se identifiquem os fatores que a determinam. Este estudo pretende rever alguns dos aspectos do estado atual do conhecimento acerca da influência de determinantes demográfico-biológicos (idade, sexo, estatuto sócio-econômico) e sócio-culturais (família, pares e professor de educação física) na atividade física de adolescentes. Nesta revisão apenas foram incluídos estudos efetuados com amostras superiores a 100 adolescentes com idades entre os 10 e os 18 anos, que tenham adotado delineamentos de pesquisa transversal e que tenham utilizado questionários. Os principais resultados e conclusões foram que: a idade parece estar negativamente associada à atividade física; o sexo masculino tende a estar mais envolvido nessas atividades; o estatuto sócio-econômico elevado parece ser um fator protetor do risco de inatividade física; a participação da família e dos pares em atividades físicas parece estar positivamente associada às atividades por parte dos adolescentes; o professor de educação física parece não representar um fator propiciador da atividade física.<br>Physical activity is important for health promotion and disease prevention. Effective physical activity programs for adolescents require a proper understanding of the determinants of activity levels. The main purpose of this paper was to review the scientific literature on determinants of physical activity among adolescents: demographic, biological (age, gender, socioeconomic status), and socio-cultural (family, peers, and physical education teachers). The review included only studies with large samples (> 100 subjects) and a cross-sectional design, and that used questionnaires to measure physical activity in adolescents (10-18 years). The main results and conclusions were: age is negatively associated with physical activity; boys tend to be more active than girls; higher socioeconomic status is positively associated with more physical activity; adolescents are more involved in physical activity when parents and peers also participate; physical education teachers do not influence the adolescents' level of physical activity