19 research outputs found
A new 2D-based method for myocardial velocity strain and strain rate quantification in a normal adult and paediatric population: assessment of reference values
<p>Abstract</p> <p>Background</p> <p>Recent advances in technology have provided the opportunity for off-line analysis of digital video-clips of two-dimensional (2-D) echocardiographic images.</p> <p>Commercially available software that follows the motion of cardiac structures during cardiac cycle computes both regional and global velocity, strain, and strain rate (SR).</p> <p>The present study aims to evaluate the clinical applicability of the software based on the tracking algorithm feature (studied for cardiology purposes) and to derive the reference values for longitudinal and circumferential strain and SR of the left ventricle in a normal population of children and young adults.</p> <p>Methods</p> <p>45 healthy volunteers (30 adults: 19 male, 11 female, mean age 37 ± 6 years; 15 children: 8 male, 7 female, mean age 8 ± 2 years) underwent transthoracic echocardiographic examination; 2D cine-loops recordings of apical 4-four 4-chamber (4C) and 2-chamber (2C) views and short axis views were stored for off-line analysis.</p> <p>Computer analyses were performed using specific software relying on the algorithm of optical flow analysis, specifically designed to track the endocardial border, installed on a Windows⹠based computer workstation. Inter and intra-observer variability was assessed.</p> <p>Results</p> <p>The feasibility of measurements obtained with tissue tracking system was higher in apical view (100% for systolic events; 64% for diastolic events) than in short axis view (70% for systolic events; 52% for diastolic events). Longitudinal systolic velocity decreased from base to apex in all subjects (5.22 ± 1.01 vs. 1.20 ± 0.88; p < 0.0001). Longitudinal strain and SR significantly increased from base to apex in all subjects (-12.95 ± 6.79 vs. -14.87 ± 6.78; p = 0.002; -0.72 ± 0.39 vs. -0.94 ± 0.48, p = 0.0001, respectively). Similarly, circumferential strain and SR increased from base to apex (-21.32 ± 5.15 vs. -27.02 ± 5.88, p = 0.002; -1.51 ± 0.37 vs. -1.95 ± 0.57, p = 0.003, respectively).</p> <p>Values of global systolic SR, both longitudinal and circumferential, were significantly higher in children than in adults (-1.3 ± 0.2, vs. -1.11 ± 0.2, p = 0.006; -1.9 ± 0.6 vs. -1.6 ± 0.5, p = 0.0265, respectively). No significant differences in longitudinal and circumferential systolic velocities were identified for any segment when comparing adults with children.</p> <p>Conclusion</p> <p>This 2D based tissue tracking system used for computation is reliable and applicable in adults and children particularly for systolic events. Measured with this technology, we have established reference values for myocardial velocity, Strain and SR for both young adults and children.</p
Transcatheter closure of atrial septal defect under combined transesophageal and intracardiac echocardiography
The Role of Social Representations in the Construction of Power Relations
The conceptualizations of power, traditionally associated with control, have been nuanced in the past decades by influential authors such as Michel Foucault, Hannah Arendt and Pierre Bourdieu. These authors offer a perspective on power focused on the agency of individuals, with an emphasis on the way the dynamics and relations of power operate. Relying on these conceptual frameworks, we argue that the theory of social representations is of particular relevance to an analysis of the construction of power relations, whether it be to criticize the effects of domination or examine those of emancipation. The results of our research on the social representations of depression illustrate the latterâs role in the construction, continuity and transformation of the power dynamics at play in the area of access to healthcare services by people who have experienced a depressive episode
Results and mid-long-term follow-up of stent implantation for native and recurrent coarctation of the aorta
Timing of pulmonary valve replacement after tetralogy of Fallot repair
Tetralogy of Fallot (TOF) is the most common form of cyanotic congenital heart disease. If left untreated, it carries a 33% mortality in the first year of life and a 50% mortality in the first 3 years of life. Since the introduction of the first open-heart repair by Lillehei and Varco in 1954, surgical management of TOF has evolved to be the primary repair during infancy in the majority of patients. Surgical management of TOF results in anatomic and functional abnormalities in the majority of patients, such as chronic pulmonary valve regurgitation and right ventricular (RV) dysfunction. Long-standing chronic pulmonary valve regurgitation can result in RV dilatation and failure, increasing tricuspid regurgitation, impaired exercise performance and supraventricular or ventricular arrhythmias. A timely reoperation may prevent these consequences, with a complete RV-function recovery. This article provides insight into the questions of when to perform a pulmonary valve implantation and in whom