Myocardial Deformation by Speckle Tracking in Severe Dilated Cardiomyopathy

Background: The high and increasing prevalence of Dilated Cardiomyopathy (DCM) represents a serious public health issue. Novel technologies have been used aiming to improve diagnosis and the therapeutic approach. In this context, speckle tracking echocardiography (STE) uses natural myocardial markers to analyze the systolic deformation of the left ventricle (LV). Objective: Measure the longitudinal transmural global strain (GS) of the LV through STE in patients with severe DCM, comparing the results with normal individuals and with echocardiographic parameters established for the analysis of LV systolic function, in order to validate the method in this population. Methods: Seventy-one patients with severe DCM (53 +/- 12 years, 72% men) and 20 controls (30 +/- 8 years, 45% men) were studied. The following variables were studied: LV volumes and ejection fraction calculated by two and three-dimensional echocardiography, Doppler parameters, Tissue Doppler Imaging systolic and diastolic LV velocities and GS obtained by STE. Results: Compared with controls, LV volumes were higher in the DCM group; however, LVEF and peak E-wave velocity were lower in the latter. The myocardial performance index was higher in the patient group. Tissue Doppler myocardial velocities (S', e', a') were significantly lower and E/e' ratio was higher in the DCM group. GS was decreased in the DCM group (-5.5% +/- 2.3%) when compared with controls (-14.0% +/- 1.8%). Conclusion: In this study, GS was significantly lower in patients with severe DCM, bringing new perspectives for therapeutic approaches in this specific population. (Arq Bras Cardiol 2012;99(3):834-842)Fapesp (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo) [2004/07474-9, 2008/05723-2]Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP

Assessment of myocardial adaptive mechanisms during pressure overload induced by pulmonary artery banding: contribution of cell proliferation

INTRODUÇÃO: Para os pacientes portadores de transposição das grandes artérias que perderam a chance da cirurgia de Jatene nas primeiras semanas de vida, indica-se realizar o preparo ventricular através da bandagem do tronco pulmonar (BTP), objetivando causar aumento na massa miocárdica. Entretanto, com o tempo, a câmara hipertrofiada pode apresentar disfunção contrátil; portanto, é importante conhecer a qualidade do tecido preparado, uma vez que já se sabe que tanto os miocardiócitos (MCD) quanto as células do interstício e vasos (I/V) são capazes de proliferar após o período neonatal. Baseando-se no condicionamento físico de atletas e considerando-se que os músculos cardíaco e esquelético são ambos estriados, postula-se a hipótese de que o tipo de preparo ventricular possa influenciar nas características do miocárdio treinado. OBJETIVOS: Identificar o tipo de mecanismo adaptativo (hipertrofia/hiperplasia) envolvido no preparo rápido do ventrículo pulmonar submetido à sobrecarga de pressão por meio de BTP, através da análise dos MCD e células do I/V, verificando se existem diferenças em relação ao tipo de treinamento (contínuo x intermitente) em comparação com os controles. MÉTODOS: Foram estudados experimentalmente 21 cabritos após o período neonatal, divididos em três grupos (C = grupo controle, n = 7, sem procedimento cirúrgico; EC = grupo de estimulação contínua, n = 7, com bandagem progressiva e permanente do tronco pulmonar durante 96 horas; EI = grupo de estimulação intermitente, n = 7, com bandagem progressiva, 12 horas ao dia, totalizando 48 horas). Todos foram submetidos a estudo ecocardiográfico basal e aqueles dos grupos EC e EI a ecocardiogramas diários para verificar a aquisição de massa muscular do ventrículo direito (VD). Após o estudo, os animais foram sacrificados, os corações retirados e cortes histológicos do VD, ventrículo esquerdo (VE) e septo interventricular (S) fixados em formalina e processados para análise. Foram estudados a porcentagem de área de colágeno através do Picro-sirius, o diâmetro dos MCD e seus respectivos núcleos e o número de MCD e células do I/V marcadas com Ki-67. As células marcadas foram avaliadas por campo microscópico e por índice (número de células Ki-67+/2000 células). O nível de significância considerado foi de 0,05. RESULTADOS: Ambos os grupos estimulados apresentaram ganho significativo de massa muscular do VD (p < 0,05). Não houve aumento na porcentagem de colágeno do VD nos grupos treinados (p = 0,403). Considerando-se o VD, os grupos EC e EI apresentaram diâmetro dos MCD maior que o grupo controle (p < 0,001), ocorrendo o mesmo com os respectivos núcleos (EI x C: p < 0,001 e EC x C: p = 0,005). O número de MCD marcados com Ki-67 foi maior no VD dos grupos estimulados comparado com o VE (p = 0,009, índice de proliferação; p = 0,001, contagem por campo), bem como para as células do I/V (p < 0,001, contagem por campo e índice). CONCLUSÕES: Tanto hipertrofia quanto hiperplasia celular estão envolvidas na adaptação do ventrículo pulmonar submetido à sobrecarga sistólica através da BTP. Ambos os tipos de condicionamento (contínuo e intermitente) provocaram hipertrofia e hiperplasia dos MCD, induziram também à mitose das células do I/V, sem deposição de colágeno intersticial ao final do experimento.INTRODUCTION: Rapid ventricular conditioning induced by pulmonary artery banding (PAB) has been indicated to those patients with transposition of the great arteries (TGA) who have lost the chance for arterial switch operation ? Jatene?s procedure ? aiming at induce myocardial mass increase. However, with time, hypertrophied chamber may exhibit contractile dysfunction, so that, it is important to assess quality of the prepared tissue, once it is of knowledge that both cardiomyocytes (CMC) and interstitial/vessel (I/V) cells are capable of proliferating after neonatal period. Based on fitness of athletes and considering that cardiac and skeletal muscles are both striated, there is the hypothesis that the type of ventricular prepare may influence the characteristics of the training myocardium. OBJECTIVES: Through CMC and I/V cells analysis, identifies the type of adaptive mechanism (hypertrophy/ hyperplasia) involved in rapid prepare of subpulmonary ventricle submitted to pressure overload by PAB, and verifies if there are differences in relation to the kind of training (continuous x intermittent), comparing them to the controls. METHODS: Twenty-one goats, beyond neonatal period, were experimentally studied. They were divided in three groups: C (control group, n = 7, with no surgical procedure); CS (continuous stimulation group, n = 7, with progressive and permanent PAB, during 96 hours); IS (intermittent stimulation group, n = 7, with progressive PAB, 12 hours/day, totalizing 48 hours). All the animals were submitted to basal echocardiograms and those from CS and IS groups to diary echocardiograms to verify right ventricular (RV) muscular mass acquisition. After the study, goats were killed, hearts excised and histological sections from RV, left ventricle (LV) and ventricular septum (VS) were formalin fixed and histologically processed. Collagen area fraction (through Picro-sirius red staining), CMC and respective nuclei diameter, and number of CMC and I/V cells Ki-67 positive were studied. Marked cells were analysed per high-power fields and by index (Ki-67 positive cells/2000 cells). The statistical significant level was set at 5%. RESULTS: Both stimulated groups presented significant RV muscular mass increase (p < 0.05). There were no augmentation in RV collagen area fraction in training groups (p = 0.403). Considering the RV, CS and IS groups showed an increase in CMC diameter compared to the control group (p < 0.01), occurring the same to respective nuclei (EI x C: p < 0.001 e EC x C: p = 0.005). Number of CMC marked with Ki-67 was greater in RV from stimulated groups in relation to LV (p = 0.009, proliferation index; p = 0.001, number/high-power fields); the same occurred to I/V cells (proliferation index and number/high-power fields: p < 0.001). CONCLUSIONS: Both cell hypertrophy and hyperplasia are involved in adaptation of the pulmonary ventricle submitted to pressure overload through PAB. Both types of conditioning (continuous and intermittent) caused CMC hypertrophy and hyperplasia, besides induced I/V cells mitosis, without interstitial collagen deposition at the end of experiment

The Echocardiography in the Cardiovascular Laboratory: A Guide to Research with Animals

A exequibilidade e o potencial para investigar o coração, sob o ponto de vista morfológico e hemodinâmico, vêm aumentando a aplicação da ecocardiografia na pesquisa. Além disso, o desenvolvimento de novas tecnologias, tais como a ecocardiografia tridimensional em tempo real e o speckle tracking, requerem validação por meio de estudos experimentais antes de serem instituídas no cenário clínico. O presente artigo objetiva fornecer informações acerca das particularidades do estudo ecocardiográfico nos mamíferos quadrúpedes, com vistas à pesquisa experimental

Estudo da Mecânica Cardíaca pelo Speckle Tracking

Speckles, ou marcadores naturais do miocárdio, originam se da interferência construtiva e destrutiva do feixe de ultrassom que incide sobre os tecidos, podem fornecer um diagnóstico precoce das alterações miocárdicas e atuar na predição de certos eventos cardíacos. Devido à sua relativa estabilidade temporal, os speckles podem ser rastreados durante o ciclo cardíaco por software dedicados, promovendo a análise da função sistólica e diastólica. São identificados tanto pela escala de cinza da ecocardiografia 2D convencional quanto pela ecocardiografia 3D, sendo independentes do ângulo de incidência do ultrassom, permitindo assim a avaliação da mecânica cardíaca nos três planos espaciais: longitudinal, circunferencial e radial. O objetivo do presente artigo é discutir o papel e o significado da deformação cardíaca obtida por meio do speckle tracking durante a avaliação da fisiologia cardíaca, e discutir as aplicações clínicas desta tecnologia ecocardiográfica inovadora

Three and two-dimensional cardiac mechanics by speckle tracking are predictors of outcomes in chagas heart disease

Abstract Chagas disease (CD) is a neglected infectious disease associated with early mortality and substantial disability. Three-dimensional speckle tracking (3D STE) may play a role in the evaluation of CD. We aim to characterize new echocardiographic variables in patients with CD and to assess the hypothesis that 3D STE may predict outcomes. Seventy-two patients with CD were included. Clinical and conventional 2D and 3D STE analysis were performed. Patients were followed up for 60 months. Clinical events were defined as hospitalization for heart failure, complex ventricular arrhythmias, heart transplant and all-cause death. Seventy-two patients were recruited and enrolled in three groups: left ventricular ejection fraction (LVEF)  0.50 (N = 30; preserved LVEF or pLVEF). After a Cox model analysis, the top predictors of composite endpoints were 2D LV global longitudinal strain (GLS) ≤ − 11.3% (AUC = 0.87), 2D LV global circumferential strain (GCS) ≤  − 10.1% (AUC = 0.79), 3D LV GLS ≤ − 13% (AUC = 0.82), 3D LV area strain ≤ − 16% (AUC = 0.81) and right ventricle (RV) GLS ≤ − 17.2% (AUC = 0.78). Patients with CD and mrLVEF were morphologically similar to the rLVEF patients despite the benign evolution as the pLVEF group. RV GLS, 2D LV GLS, 2D LV GCS, 3D LV GLS, and 3D LV area strain are strong predictors of 60 months outcomes in patients with CD

Influência do Exercício Físico sobre a Mecânica de Contração do Ventrículo Esquerdo após Infarto do Miocárdio

Resumo Fundamento O exercício exerce um papel positivo na evolução da doença cardíaca isquêmica, melhorando a capacidade funcional e prevenindo o remodelamento ventricular. Objetivo Investigar o impacto do exercício sobre a mecânica de contração do ventrículo esquerdo (VE) após um infarto agudo do miocárdio (IAM) não complicado. Métodos Um total de 53 pacientes foram incluídos e alocados aleatoriamente em um programa de treinamento supervisionado (grupo TREINO, n=27) ou em um grupo CONTROLE (n=26) que recebeu recomendações usuais sobre a prática de exercício físico após um IAM. Todos os pacientes realizaram um teste cardiopulmonar e um ecocardiograma com speckle tracking para medir vários parâmetros da mecânica de contração do VE em um mês e cinco meses após o IAM. Um valor de p <0,05 foi considerado para significância estatística nas comparações das variáveis. Resultados Não foram encontradas diferenças nas análises dos parâmetros de strain circunferencial, radial ou longitudinal do VE entre os grupos após o período de treinamento. Após o programa, a análise da mecânica de torção revelou uma redução na rotação basal do VE no grupo TREINO em comparação ao grupo CONTROLE (5,9±2,3 vs. 7,5±2.9o; p=0,03), bem como na velocidade rotacional basal (53,6±18,4 vs. 68,8± 22,1 º/s; p=0,01), velocidade de twist (127,4±32,2 vs. 149,9±35,9 º/s; p=0,02) e na torção (2,4±0,4 vs. 2,8±0, º/cm; p=0,02). Conclusões A atividade física não causou melhora significativa nos parâmetros de deformação longitudinal, radial ou circunferencial do VE. No entanto, o exercício teve um impacto significativo sobre a mecânica de torção do VE, que consistiu em uma redução na rotação basal, na velocidade de twist, na torção, e na velocidade de torção, que pode ser interpretada como uma “reserva” de torção ventricular nessa população

Early Diagnosis of Myocardial Dysfunction in Patients With Hematological Malignancies Submitted to Chemotherapy. Preliminary Results.

Early Diagnosis of Miocardial Dysfunction in Patients with Hematological Malignancies Submitted to Chemotherapy. Preliminary \ud Background: Considering the current diagnostic improvements and tl1erapeutic approaches, patients witl 1 cancer can now be healed or keep the disease under control, still, the chemotherapy may cause heart damage, evolving to Congestive Heart Failure. Recognition of those changes increases the chances of control the endpoints; hence, new parameters of cardiac and fluid mechanics analysis have been used to assess the myocardial function, pursuing an earlier diagnosis of the cardiac alterations. This study aimed to detect early cardiac dysfunction consequently to chemotherapy in patients with hematological malignancies (HM). Methods: Patients with leukemia and lymphoma, submitted to chemotherapy, without knowing heart diseases were studied. Healthy volunteers served as the control group. Conventional 2DE parameters of myocardial function were analyzed. The peak global longitudinal, circumferential and radial left ventricular (LV) strain were deternined by 2D and 3D speckle tracking (STE); peak area strain measured by 3D STE and LV torsionn, twisting rate, recoil / recoil rate assessed by 2D STE. The LV vortex formation time (VFT) during the rapid diastolic filling was estimated by the 2D mitral valve (MV) planimetry and Pulsed Doppler LV inflow by: VFT- 4(1-β) / π x α3 x LVEF Where 1- β is the E wave contribution to the LV stroke volume and α3 is a volumetric variable related to the MV area. The statistical level was settled on 5%. Results: See Table. Conclusion: Despite the differences between the two groups concerning the LVESV, LVEF and E´, those parameters still are in the normal range when considering the patients submitted to chemotherapy; thus, in the clinical setting, they are not so noticeable. The 3D GLS was smaller among the patients, oppositely to the 2D GLS, suggesting that the former variable is more accurate to assess tlhe LV systolic function. The VFT is a dimensionless measure of the optimal vortex development inside the LV chamber; reflecting the efficiency of the diastolic filling and, consequently, blood ejection. This index showed to be diminished in patients with HM submitted to chemotherapy, indicating an impairment of the in1pulse and thrust, hence appearing to be a very early marker of diastolic and systolic dysfunction in this group.CNP

Anatomicosurgical segmentectomy of the left ventricle for systematized partial resection of the heart: an experimental study

A surgical experimental investigation is being carried out in an attempt to provide a viable alternative to the current approaches to cardiac resection of the left ventricular myocardium in cases of cardiomyopathies with dilated ventricle. The experiments are based upon the presence of anatomicosurgical segments in the dog's heart similar to those existing in the atria and ventricles of humans. So far three mongrel dogs (weight 15 kg) were submitted to cardiac catheterism to evaluate the anatomy of the coronary arteries and their branches, the function and cavity of the left ventricle (LV). A lateral thoracotomy on the left side was performed to expose the heart. Cardiopulmonary bypass (CPB) of each animal was established through the right atrium and the femoral artery (4 mg/kg Heparin, at 32°C, intermittent aorta cross-clamping). The left marginal artery and veins were ligated, causing an area of acute myocardial infarction, showing well-defined sharp limits. Such an area was then resected and the left ventricle was reconstructed. The animals were weaned from CPB, one dog having remained in a stable condition during a 7-day period of observation. The second was sacrificed after 4-day period of observation and the third dog died four hours after CPB owing to an excessive reduction of the LV chamber related to an anatomical variation. Pre and post operation transthoracic echocardiograms were obtained after undergoing cardiac catheterism. The echocardiogram revealed discrete mitral insufficiency, reduction of the diameter of the left ventricle with approximation of the papillary muscles, a dysfunction and an impressive reduction of the cavity of the left ventricle. Peri-sutural areas of infarction were not observed. The orientation given by the anatomicosurgical segmentation of the coronary circulation is an important alternative to the present surgical treatment of cardiomyopathies with dilated ventricle