A Curva Volume-Tempo Obtida pela Ecocardiografia Tridimensional na Cardiomiopatia Chagásica: Análise do Mecanismo das Adaptações Hemodinâmicas / The Volume-Time Curve by Three-Dimensional Echocardiography in Chagas Cardiomyopathy: Insights into the Mechanism of Hemodynamic Adaptations

Resumo Fundamento A ecocardiografia tridimensional (ECO 3D) permite a geração de uma curva volume-tempo representativa das alterações no volume ventricular esquerdo (VE) ao longo de todo o ciclo cardíaco. Objetivo O presente estudo tem como objetivo demonstrar as adaptações hemodinâmicas presentes na cardiomiopatia chagásica (CC) por meio das medidas de volume e fluxo obtidas pela curva volume-tempo por ECO 3D. Métodos Vinte pacientes com CC e 15 indivíduos saudáveis foram incluídos prospectivamente em um estudo de desenho transversal. Realizou-se ECO 3D em todos os indivíduos e as curvas volume-tempo do VE foram geradas. O fluxo foi obtido pela primeira derivada da curva volume-tempo por meio do software MATLAB. A significância estatística foi definida com p<0,05. Resultados Embora os pacientes com CC tivessem menor fração de ejeção do VE em comparação com o grupo controle (29,8±7,5 vs. 57,7±6,1, p<0,001), o volume (61,5±25,2 vs. 53,8±21,0, p=0,364) e o fluxo de ejeção máximo durante a sístole (-360,3±147,5 vs. -305,6±126,0, p = 0,231) mostraram-se semelhantes entre os grupos. Da mesma forma, o fluxo máximo na fase de enchimento inicial e durante a contração atrial mostrou-se semelhante entre os grupos. Um aumento na pré-carga expressa pelo volume diastólico final do VE (204,8±79,4 vs. 93,0±32,6), p<0,001) pode manter o fluxo e o volume ejetado semelhantes aos dos controles. Conclusão Com uma ferramenta não invasiva, demonstramos que o aumento no volume diastólico final do VE pode ser o principal mecanismo de adaptação que mantém o fluxo e o volume ejetado no cenário de disfunção sistólica ventricular esquerda severa.

Abstract Background Three-dimensional echocardiography (3D ECHO) allows the generation of a volume-time curve representative of changes in the left ventricular (LV) volume throughout the entire cardiac cycle. Objective This study aims to demonstrate the hemodynamic adaptations present in Chagas cardiomyopathy (CC) by means of the volume and flow measurements obtained by the volume-time curve by 3D ECHO. Methods Twenty patients with CC and 15 healthy subjects were prospectively enrolled in a cross-sectional design study. 3D ECHO was performed in all subjects and the volume over time curves of the LV was generated. The flow was obtained by the first derivative of the volume-time curve using the software MATLAB. Statistical significance was set at p<0.05. Results Although CC patients had lower LV ejection fraction compared to the control group (29.8±7.5 vs. 57.7±6.1, p<0.001), stroke volume (61.5±25.2 vs. 53.8±21.0, p=0.364) and maximum ejection flow during systole (-360.3±147.5 vs. -305.6±126.0, p=0.231) were similar between the groups. Likewise, the maximum flow in the early diastolic filling phase and during atrial contraction was similar between groups. An increase in preload expressed by LV end diastolic volume (204.8±79.4 vs. 93.0±32.6), p<0.001) may maintain the flow and stroke volumes similar to the controls. Conclusion Using a non-invasive tool, we demonstrated that an increase in LV end-diastolic volume may be the main adaptation mechanism that maintains the flow and stroke volumes in the setting of severe LV systolic dysfunction.

COVID-19 epidemic curve in Brazil: a sum of multiple epidemics, whose inequality and population density in the states are correlated with growth rate and daily acceleration. An ecological study

ABSTRACT Background: The epidemic curve has been obtained based on the 7-day moving average of the events. Although it facilitates the visualization of discrete variables, it does not allow the calculation of the absolute variation rate. Recently, we demonstrated that the polynomial interpolation method can be used to accurately calculate the daily acceleration of cases and deaths due to COVID-19. This study aimed to measure the diversity of epidemic curves and understand the importance of socioeconomic variables in the acceleration, peak cases, and deaths due to COVID-19 in Brazilian states. Methods: Epidemiological data for COVID-19 from federative units in Brazil were obtained from the Ministry of Health's website from February 25 to July 11, 2020. Socioeconomic data were obtained from the Instituto Brasileiro de Geografia e Estatística (https://www.ibge.gov.br/). Using the polynomial interpolation methods, daily cases, deaths and acceleration were calculated. Moreover, the correlation coefficient between the epidemic curve data and socioeconomic data was determined. Results: The combination of daily data and case acceleration determined that Brazilian states were in different stages of the epidemic. Maximum case acceleration, peak of cases, maximum death acceleration, and peak of deaths were associated with the Gini index of the gross domestic product of Brazilian states and population density but did not correlate with the per capita gross domestic product of Brazilian states. Conclusions: Brazilian states showed heterogeneous data curves. Population density and socioeconomic inequality were correlated with a more rapid exponential growth in new cases and deaths.

Covid-19 growth rate analysis: application of a low-complexity tool for understanding and comparing epidemic curves

Abstract INTRODUCTION: The acceleration of new cases is important for the characterization and comparison of epidemic curves. The objective of this study was to quantify the acceleration of daily confirmed cases and death curves using the polynomial interpolation method. METHODS: Covid-19 epidemic curves from Brazil, Germany, the United States, and Russia were obtained. We calculated the instantaneous acceleration of the curve using the first derivative of the representative polynomial. RESULTS: The acceleration for all curves was obtained. CONCLUSIONS: Incorporating acceleration into an analysis of the Covid-19 time series may enable a better understanding of the epidemiological situation.

Displasia das valvas atrioventriculares em pacientes com diagnóstico de Síndrome de Down e sem cardiopatia congênita / Atrioventricular valve dysplasia in patients with Down Syndrome without congenital heart disease

Introdução: É bastante conhecido que a cardiopatia congênita está relacionada à síndrome de Down. Entretanto, existem raros relatos de casos de displasia valvar em crianças portadoras de síndrome de Down, sem cardiopatia associada. Objetivos: Verificar a presença e magnitude de alterações nas valvas atrioventriculares, em pacientes com diagnóstico de síndrome de Down, sem cardiopatia congênita associada. Método: Foi realizado um estudo transversal, com captação prospectiva de 162 pacientes, avaliados pela ecocardiografia, classificados em Grupo 1, portadores de Síndrome de Down (n = 81) e Grupo 2, crianças normais, do ponto de vista genético e cardiológico (n = 81). Resultados: A frequência de displasia das valvas tricúspide e mitral foi superior no grupo 01, quando comparado ao grupo 2 (55 versus 0, p<0,00001 e 20 versus 2, p < 0,0001, respectivamente). No grupo 1, 19 crianças apresentaram comprometimento simultâneo das valvas tricúspide e mitral. O comprometimento isolado da valva tricúspide ocorreu em 36 casos e da valva mitral ocorreu em apenas 01 caso (p < 0,01). Vinte e cinco crianças do Grupo 1 tinham ambas as valvas normais. Conclusão: Este estudo descreveu, pela primeira vez, a alta frequência de displasia nas válvulas tricúspide e mitral, em crianças e adolescentes com síndrome de Down, sem doença cardíaca congênita.

Introduction: It is well known that congenital heart disease is related to Down syndrome, however there are rare reports of valvular dysplasia in children with Down syndrome without associated congenital heart disease. Objectives: To determine the presence and magnitude of changes in atrioventricular valves in patients with Down’s syndrome without associated congenital heart diseases. Methods: We conducted a prospective cross-sectional study of 162 patients assessed by echocardiography, classifi edin Group 1, patients with Down syndrome (n = 81) and Group 2, genetically normal children without congenital heart disease. (n=81). Results: Th e frequency of dysplasia of tricuspid and mitral valves was higher in the group 1 compared to group 2 (55 vs 0, p <0.00001 and 20 versus 2, p <0.0001, respectively). In group 1, 19 children had simultaneous involvement of the tricuspid and mitral valves. Th e isolated involvement of the tricuspid valve occurred in 36 cases and isolated involvement of the mitral valve inonly one case (p <0.01). Twenty-fi ve children in a group containing both normal valves. Conclusion: To our knowledge, this study described for the fi rst time the high frequency of dysplasia in the tricuspid and mitral valves in children with Down’s syndromewithout congenital heart disease.

Myocardial dysfunction in chagasic patients with no apparent heart disease / Disfunção miocárdica em pacientes chagásicos sem cardiopatia aparente

FUNDAMENTO: O índice de Tei avalia simultaneamente as funções sistólica e diastólica dos ventrículos. Apresenta boa correlação com dados hemodinâmicos e tem sido capaz de detectar alterações na função ventricular iniciais de diversas etiologias. OBJETIVO: Estudar alterações iniciais da função biventricular em pacientes chagásicos sem cardiopatia aparente por meio do índice de Tei. MÉTODOS: Foram avaliados 48 indivíduos. Grupo 1, constituído por 25 pacientes com diagnóstico de doença de Chagas, sem cardiopatia aparente e ecocardiograma normal; grupo 2, constituído por 23 indivíduos sadios com sorologia negativa para doença de Chagas. RESULTADOS: O índice de Tei foi significativamente mais elevado no grupo de chagásicos sem cardiopatia aparente, quando comparado aos controles. Índice de Tei do ventrículo esquerdo (0,48±0,11 x 0,36±0,06, p<0,001) , índice de Tei do ventrículo direito (0,34±0,10 x 0,26±0,07, p=0,001). O índice de Tei do ventrículo esquerdo foi considerado alterado em 48 por cento dos chagásicos e o do ventrículo direito em 28 por cento. CONCLUSÃO: Pacientes com doença de Chagas sem cardiopatia aparente apresentam alteração precoce dos ventrículos direito e esquerdo.

BACKGROUND: The Tei index simultaneously evaluates the ventricular systolic and diastolic functions. It has a good correlation with hemodynamic data and has enabled the detection of initial ventricular function alterations of different etiologies. OBJECTIVE: To study initial biventricular function alterations in chagasic patients with no apparent heart disease, using the Tei index. METHODS: Forty eight individuals were evaluated. Group 1 was comprised of 25 patients diagnosed with Chagas´ disease with no apparent heart disease and normal echocardiogram; group 2 was comprised of 23 healthy individuals with negative serological tests for Chagas´ disease. RESULTS: The Tei index was significantly higher in the group of chagasic patients with no apparent heart disease when compared to that of the control group: left ventricular Tei index (0.48 ± 0.11 vs. 0.36 ± 0.06, p < 0.001) , right ventricular Tei index (0.34 ± 0.10 vs. 0.26 ± 0.07, p = 0.001). The left and right ventricular Tei indexes were considered abnormal in 48 percent and 28 percent of the chagasic patients, respectively. CONCLUSION: Chagasic patients with no apparent heart disease present early alterations of the right and left ventricles.