IntroductionObesity has become an epidemic in both developed and developing countries. Statistics from the United States of America reveal a 32.2% rate of obesity among adult men and 25.5% among adult women [1]. It is estimated that Five to 10 million adult individuals in the United States alone have severe obesity (body mass index ≥ 40 kg/m 2 ) [2]. In developing countries, the prevalence of obesity has reached more than 20% of the population. Reports on the pediatric population (children and adolescents aged two to 19 years) reveal that 11.9% are at or above the 97 th percentile of the body mass index (BMI) for age, 16.9% are at or above the 95 th percentile and 31.7% are at or above the 85 th percentile [3]. Ten percent of children starting school in the United Kingdom are already obese [4]. Cardiovascular complications associated with obesity contribute to high rates of morbidity and mortality. Structural and functional alterations in the heart, such as left ventricular hypertrophy, diastolic/systolic dysfunction and atrial enlargement, are well established in adult and pediatric patients with obesity [5][6][7][8][9][10]. Left atrial dysfunction with left ventricular diastolic dysfunction in subjects with preserved systolic function is well established in patients with hypertension [11,12]. There is strong evidence that left atrial enlargement and dysfunction are associated with an increase in morbidity and mortality rates in patients with cardiovascular disease and present clinical relevance with respect to the rate of long-term events, survival and the risk of developing atrial fibrillation [13]. Using Doppler-derived strain and strain rate (SR) MethodsObese pediatric patients six to 18 years of age with a BMI above the 95 th percentile were prospectively recruited from the nutrition clinic of a university hospital (Universidade Federal de Minas Gerais) in Belo Horizonte, Brazil. The control group was formed by children aged six to 18 years with a BMI below the 85 th percentile recruited from the general pediatrics clinic of the same institution. Patients with a history of hypertension, diabetes mellitus, endocrinological disorders, hereditary or inflammatory systemic diseases, sleep apnea (according to parents' information) and athletes were excluded in both groups. This study received approval from the Human Research Ethics Committee of the institution and written informed consent was obtained from all participants and/or parents. The participants were weighed in light clothing without shoes using a Welmy ® scale with a capacity of 300 Kg and accuracy of 100 g. Height was measured with a stadiometer (accuracy of 0.5 cm). BMI was calculated using the conventional formula of weight in kilograms divided by the square of height in AbstractBackground : Left atrial enlargement and right and left ventricular dysfunction have been described in obese Patients. A number of studies have also described atrial dysfunction in obese children and adolescents.

Introduction: During the last decade, the traditional model of medical education was widely debated, and recently, the Covid-19 pandemic added new challenges in teaching and learning in medical education. The Worked Example is an instructional tool in which an expert shows a detailed problem solution for a learner. Objective: This study aimed to compare, in an experimental study with medical students, lectures in online format with Worked Example for teaching chest tomography. Method: Experimental study through an educational intervention with medical students in the initial and final stages of clinical practice. Result: Analysis of variance of repeated measures (ANOVA) was used in the statistical analysis. There was a significant difference between the grades before and after training (F1; 74 = 46.008; p < 0.001) and between the course phases studied (F2; 148 = 19.452; p < 0.001). There was no statistically significant difference between the groups (F2; 74 = 1.401; p = 0.240). There was no significant difference in mental effort reported in the comparison between groups (F1; 69 = 0.092; p = 0.762), but students in the 2th year had a significantly higher effort score. Conclusion: Worked Example, which is a good technique for students and suitable for digital formats, was equally effective as lecture, a well-known instructional method for teaching radiology.

Resumo: Introdução: Durante a última década, o modelo tradicional de ensino médico foi amplamente debatido, e, há pouco tempo, a pandemia da Covid-19 impôs novamente mudanças, iniciadas em caráter de urgência em todo o mundo, trazendo novos desafios à formação médica no que concerne ao ensino e à aprendizagem. A estratégia de ensino conhecida como Worked Example é uma ferramenta instrucional na qual um especialista mostra a solução de um determinado problema para um aprendiz de forma pormenorizada. Objetivo: Este estudo teve como objetivo comparar as aulas expositivas em vídeo com a técnica Worked Example para ensino de tomografia de tórax. Método: Trata-se de um estudo experimental realizado, por meio de uma intervenção educacional, com alunos do curso de Medicina em fases iniciais e finais da prática clínica. Resultado: A análise de variância de medidas repetidas (ANOVA) foi usada na análise estatística. Houve diferença significativa entre as notas antes e depois do treinamento (F1; 74 = 46,008; p < 0,001) e entre as fases do curso (F2; 148 = 19,452; p < 0,001). Não houve diferença estatisticamente significativa entre os grupos (F2; 74 = 1,401; p = 0,240). Não houve diferença significativa no esforço mental referido na comparação entre grupos (F1; 69 = 0,092; p = 0,762), porém os alunos do segundo ano apresentaram um escore de esforço significativamente maior. Conclusão: O Worked Example, uma técnica com boa aplicabilidade para estudantes da graduação e adequada para formatos digitais, mostrou-se igualmente eficaz a aula expositiva, técnica consagrada no ensino de radiologia.