Cardiovascular diseases are responsible for approximately a third of all death worldwide, with hypertension being a major risk factor for many of those. Hypertension can lead to left ventricle hypertrophy and diastolic and systolic dysfunction. Myocardial deformation parameters have been shown to have high sensitivity at the early stage of contractile dysfunction. They can be derived from myocardial tagging, considered to be the goldstandard method, or from routinely acquired cine images using feature tracking (FT) techniques. This work aimed to validate FT as a post processing technique. Three FT software packages were used to measure strain parameters in healthy subjects and hypertensive patients in order to assess agreement. Intra- and inter-observer reproducibility was also investigated. The CVI42 software was found to have the best reproducibility. Good agreement across the three software packages and both groups was also observed for circumferential strain calculated from mid-ventricle short axis and longitudinal strain parameters. CVI42 was also compared to the reference tagging analysis by applying both techniques to a healthy and hypertensive patient cohort. Although tagging could discriminate between the two populations (longitudinal strain), no statistically significant differences were found by CVI42. The final validation step was to generate simulation models mimicking simplified cardiac views to compare the experimental results against a true gold-standard for which strain values are known. Two commercial FT software packages were used to analyze the simulated cine images with increasing complexity levels. Both showed inaccurate tracking and high errors compared to analytical values. This indicated that more realistic and complex numerical models should be investigated. Although FT is a relatively new and promising technique, the results demonstrated that it still requires going through standardization to better understand inter-vendor variability.

Background: Accurate assessment of left ventricular (LV) systolic function in chronic severe primary mitral regurgitation (MR) is important as the aim is to consider surgical repair prior to the onset of irreversible LV dysfunction. However this can be difficult to judge as conventional measures of LV function (such as ejection fraction, EF) may remain normal despite impaired LV contractility due to the increased preload of the condition. Advanced echocardiographic techniques, including deformation imaging, appear promising as they are less load dependent. As the earliest symptoms in severe MR are usually exertional, this study aimed to assess markers of LV deformation on exercise in patients with normal resting EF in order to try and identify the earliest signs of LV decompensation.Methods: Transthoracic echocardiography was carried out at rest and on submaximal supine exercise in asymptomatic patients with moderate to severe chronic primary MR and matched controls. Conventional contractile reserve (CR) as measured by EF change on exercise was used to subdivide patients into those with preserved (CR+) and abnormal (CR-) LV function. Myocardial strain and twist were assessed using the speckle tracking technique.Results: MR patients failed to show the normal enhancement in systolic twist on exercise. The onset and peak of untwisting were delayed in MR at rest and normalised on exercise in CR+ but not in CR-. Abnormalities in twist on exercise worsened with increasing resting preload. Longitudinal strain tended to increase normally on exercise in CR+ but not in CR-. Systolic longitudinal strain rate correlated with twist at rest and on exercise, whereas diastolic strain rate correlated with the timing of untwisting on exercise.Conclusion: Abnormalities in myocardial deformation are seen at rest and on exercise in patients with severe MR, particularly in those with decompensated LV function. This may contribute to the development of functional impairment with progressive disease.

Introduction : La resynchronisation cardiaque (CRT) améliore les patients insuffisants cardiaques, symptomatiques malgré un traitement médical optimal et présentant un élargissement du QRS>120ms. Cependant, un tiers des patients ne répondent pas à cette thérapie. L'objet de cette thèse est d'identifier les mécanismes déterminant la réponse à la CRT. Méthode: Dans un premier temps, nous avons apprécié la précision des méthodes de quantification de la contraction myocardique utilisées pour caractériser l'asynchronisme. Ensuite, nous avons évalué les facteurs liés à l'asynchronisme et à la réponse à la CRT (fibrose, nécrose myocardique, réserve contractile). De plus, nous avons développé et validé un nouvel indice permettant d'évaluer les conséquences « énergétiques » de l'asynchronisme sur la contraction myocardique. Résultats: Nous avons démontré que le strain longitudinal en speckle tracking était supérieur au Doppler tissulaire pour évaluer la déformation et l'asynchronisme myocardique et qu'il était mieux corrélé au pronostic des patients insuffisants cardiaques. Ensuite nous avons mis en évidence que le retard de contraction mécanique n'était pas lié simplement à un bloc de conduction électrique mais qu'il était observé pour l'ensemble des segments myocardiques nécrosés. De plus ces zones de fibrose et de nécrose évaluées en échographie de stress influencent la réponse à la CRT. Ces résultats suggèrent l'importance de considérer le retard de contraction et la contractilité résiduelle pour prédire la réponse à la CRT. A partir de cette hypothèse, nous avons validé un indice unique associant l'asynchronisme et la contractilité résiduelle pour évaluer la perte d'énergie contractile liée au retard de contraction. Conclusion : Les travaux réalisés ont permis de développer des outils pour mieux apprécier les conséquences de l'asynchronisme myocardique. / Background: Randomized studies demonstrated that Cardiac Resynchronization Therapy (CRT) improves symptoms and survival in heart failure patients with wide QRS duration that remains symptomatic despite optimal medical treatments. However, up to 40% of patients did not response to CRT. The purpose of this work was to investigate the underlying mechanisms of mechanical cardiac dyssynchrony to optimize the identification of responder to CRT. Methods: The first part of our study was to identify the accurate echocardiography method for quantifying of myocardial deformation and dyssynchrony (Tissue Doppler Imaging and Speckle tracking analysis). Next, we studied factors (myocardial scar and contractile reserve) interacting with myocardial dyssynchrony and response to CRT. Then, we developed and validated a mathematical model (strain delay index) to assess the wasted energy related to myocardial dyssynchrony. Results: First we demonstrated that longitudinal strain computed from spec kle tracking analysis was superior to tissue Doppler imaging in assessing myocardial dyssynchrony and function with a better correlation with outcome in heart failure patients. Next, we showed that mechanical dyssynchrony was not specific of electrical delay but was prevalent in scar segments. In addition, using dobutamine stress echocardiography, we demonstrated that contractile reserve in delayed segments greatly impacts on response to CRT. Then, we proposed and validated a mathematical model, the strain delay index for assessing the wasted energy related to mechanical dyssynchrony. Conclusion: The mathematical model proposed in the present study to assess the impact of dyssynchrony on myocardial contractility allows a better identification of responder to CRT.

Introduction : Les paramètres éjectionnels d’évaluation de la fonction ventriculaire gauche, sont directement influencés par la post-charge. Dans ce contexte chez l’hypertendu, une analyse complète de la performance du ventricule gauche (VG) doit pouvoir intégrer des paramètres hémodynamiques (variations de volume du VG vs variations de pressions aortique) mais aussi des paramètres de «déplacement » des parois. L’objectif de cette thèse est de déterminer avec des techniques non invasives le couplage ventriculo-aortique chez l’hypertendu.Méthodes : Les courbes de pression-volume ont été obtenues par échographie 3D en temps réel pour les volumes et tonométrie pour la pression carotidienne. A partir des boucles pression-volume, une méthode des moindres carrés non linéaire est utilisée pour construire la droite d’élastance. Le couplage ventriculo-aortique est estimé par le rapport de l’élastance télé-systolique de sortie du VG (Ees) et d’entrée aortique (Ea). Le transfert d’énergie du VG à l’aorte (rendement) est calculé par le rapport de la puissance d’éjection et de la puissance de déformation myocardique.Résultats : L’étude de validation de notre nouvelle méthode de modélisation d’Ees montre une bonne sensibilité et reproductibilité par rapport aux méthodes invasives de référence. Outre sa précision, l’avantage de notre méthode est la simplicité de son application clinique. Les premiers résultats de ce travail montrent que à un stade précoce de l’HTA, l’augmentation simultanée de la puissance d’éjection et d’Ea est compensée par une augmentation du rendement du VG et d’Ees pour un couplage ventriculo-aortique qui reste préservé.Conclusion : Le travail de modélisation de la relation pression-volume de cette thèse a permis son application clinique sur une population de sujets hypertendus. Ces premiers résultats positifs ont permis la mise en place d’une étude randomisée sur l’influence de l’apport sodé sur le couplage ventriculo-aortique chez l’hypertendu. L’avantage de cette nouvelle méthode de calcul d’Ees, basée sur l’échocardiographie 3D en temps réel, permet de se passer de toutes les hypothèses géométriques qui étaient jusqu’alors nécessaires pour les études en imagerie bidimensionnelle. Le recours à l'imagerie reste en revanche plus complexe pour l’analyse des déplacements en 3D qui nécessitent encore un travail de modélisation. / Introduction : In addition to contractility, afterload is one of the main determinants of left ventricular (LV) performance. Thus, analysis of LV function in hypertension not only requires incorporation of hemodynamics parameters such as LV time-varying volume and pressure, but also LV wall strain and stress. The aim of the present study is to evaluate non invasively LV-arterial coupling in hypertension.Method : LV volumes and pressures curves were obtained from real-time 3D echocardiography (RT3DE) and carotid tonometry, respectively. The pressure-volume (P-V) curves thus obtained were fitted with a non linear least squares method. We then computed the slope and the intercept of time varying élastance, and volume intercept V0. LV-aortic coupling is estimated by the ratio of LV and aortic elastance (Ees and Ea). Energy transfer from the left ventricle to aorta is defined as the ratio of external work and myocardial strain work (Pmeca). Cyclic variations of wall thickness and strain rate were measured by 2D speckle-tracking. Pmeca was calculated according to the produce of LV wall stress with strain rate.Result : A good univariate relationship and a good agreement were found between previous invasive calculation of Ees and our new proposed “Ejection P-V Curve” method. In hypertensive patients, increase in Ea and LV efficiency were compensated by a parallel increase in Ees without change in Ea/EesConclusion : Ees and V0 can be estimated non invasively from modeling of the P-V curve during ejection. This approach was found to be reproducible and sensitive enough to detect an expected difference in LV contractility in hypertensive patients. Due to its non invasive nature, our new proposed “Ejection P-V Curve” method is now applicable to a randomized study of the effect of sodium intake on LV performance in hypertension. Among strengths of these new methods based on RT3DE, is to exclude the necessity of geometrics assumptions for the evaluation of LV volumes. However, 3D analysis of LV strain is not yet fully-developed, with the necessity to improve the performance of frame acquisition and modeling.

Orientador: Paulo Sergio Patto dos Santos / Resumo: A nalbufina é um opioide agonista-antagonista com propriedades analgésicas adequadas e poucos efeitos depressores no sistema respiratório. Sua utilização na medicina veterinária é limitada pois muitos veterinários desconhecem suas vantagens. Além disso, seus efeitos na função cardíaca são pouco estudados. Portanto, com o estudo objetivou-se avaliar os efeitos da infusão contínua de nalbufina na função sistólica e diastólica do ventrículo esquerdo em cães saudáveis anestesiados com sevofluorano. Foram utilizados dezoito cães fêmeas de diversas raças ou sem raça definida, com idade média de 2 ± 1 anos e peso médio de 9,9 ± 3,8 kg. Os cães foram aleatoriamente submetidos a dois grupos denominados: nalbufina (GN) e controle (GC), com nove animais para cada grupo. Os animais foram induzidos e mantidos sob anestesia com sevofluorano (2V%). No GN foi administrado bolus intravenoso de nalbufina (0,3 mg/kg), seguido de infusão continua (0,4 mg/kg/h). O GC recebeu solução salina (NaCl 0,9%), em volumes idênticos em bolus e infusão ao GN. As variáveis ecocardiográficas de função sistólica e diastólica e os parâmetros hemodinâmicas foram determinadas no momento basal (antes do bolus) e 20, 40, 60 e 80 minutos após o início da infusão contínua. Não houve diferença entre os grupos para os parâmetros de função sistólica e diastólica ventricular esquerda derivados da ecocardiografia convencional e speckle tracking bidimensional. Do mesmo modo, as variáveis hemodinâmicas não apresentaram dife... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Nalbuphine is an agonist-antagonist opioid with adequate analgesic properties and few depressant effects on the respiratory system. Its use in veterinary medicine is limited due to the unknown of its effects on cardiac function. The aim of this study was to assess the effects of a continuous rate infusion (CRI) of nalbuphine on left ventricular systolic and diastolic function of healthy sevoflurane-anesthetized dogs. Were used eighteen mixed-breed bitches ageging 2 ± 1 years and weighing 9.9 ± 3.8 kg. Dogs were randomly assigned to one of two groups: nalbuphine (GN, n=9); and control (GC, n=9). Anesthesia was induced and maintained with sevoflurane (2V%) followed by an intravenous (IV) bolus of nalbuphine (0.3 mg/kg) or 0.9% NaCl at equal volume, then CRI of nalbuphine (0.4 mg/kg/h) or 0.9% NaCl at equal infusion rate. Echocardiographic and hemodynamic variables were determined at baseline and 20, 40, 60 and 80 minutes following start of CRI. No differences were found between groups for left ventricular systolic and diastolic variables obtained through conventional echocardiography and two-dimensional speckle tracking. Likewise, hemodynamic variables did not differ between groups. The E′/A′ ratio significantly increased at 20 minutes compared to baseline only in GN. Nalbuphine given at a CRI does not influence left ventricular systolic and diastolic function in healthy sevoflurane-anesthetized dogs. / Doutor

Background: Coarctation of the aorta (CoA) is a congenital heart disease which represents a narrowing of the proximal descending aorta, hence increasing pressure afterload to the left ventricle (LV). Conventional treatment of native CoA is surgical repair, however potential recurrence or other related complications e.g. aortic rupture, heart failure and cerebrovascular events are common. Thus, lifelong follow-up of these patients is required. Echocardiography is the most patient’s friendly method to evaluate CoA and in particular its effect on LV function. Moreover, the novel speckle tracking echocardiography (STE) is an important method to assess subclinical LV dysfunction, a technique that promises better evaluation of LV function in these patients. The aims of this thesis were to review the literature on LV function in children with CoA using myocardial deformation imaging technologies, hence, to better understand the current knowledge and vagueness of the scientific evidence. We also aimed to study the effect of early CoA repair on the structure and function of LV and ascending aorta. In addition, we wished to establish in a meta-analysis format normal values of speckle tracking derived strain and strain rate values. Methods: Study 1. We have systematically searched the PubMed, and studies that fulfilled the inclusion criteria were critically analyzed and presented on a narrative form. Study 2 and 3. In addition to conventional echocardiographic measures of LV and ascending aorta, we measured longitudinal strain and strain rate of the LV using a vendor independent software, TomTec. We have also measured the aorto-septal angle (AoSA). Data was compared with normal healthy controls. Study 4. Electronic databases were systematically searched and suitable studies were meta analyzed using Comprehensive meta-analysis version 3 software. Results: Study 1. In 7/4945 included articles, 123 and 76 patients with congenital aortic stenosis (CAS) and CoA were reported, respectively. Normal conventional LV function, with subclinical myocardial dysfunction were reported in all studies before intervention. After intervention, a consistent improvement of myocardial deformation parameters was documented, even though not reaching normal values. Study 2. In 21 patients with CoA, LV function significantly improved after intervention (p <0.001), however normal values were not reached even at medium-term follow-up (p = 0.002). Medium-term longitudinal strain correlated with pre intervention LV ejection faction (EF) (r = 0.58, p = 0.006). Medium-term subnormal values were more frequently associated with Bicuspid aortic valve (BAV) (33.3% vs. 66.6%; p <0.05). Study 3. AoSA was abnormally wide before intervention, in particular at peak ejection in the descending aorta (p <0.0001), and correlated with CoA pressure gradient. After intervention, AoSA normalized and significantly correlated with the increase of LV cavity function and overall LV deformation parameters. Study 4. In a meta-analysis of 28/282 studies including 1192 subjects, strain and strain rate values were established. Longitudinal strain normal mean values varied from -12.9 to -26.5 (mean, -20.5; 95 % CI, -20.0 to -21.0). Normal mean values of circumferential strain varied from -10.5 to -27.0 (mean, -22.06; 95 % CI, -21.5 to -22.5). Radial strain normal mean values varied from 24.9 to 62.1 (mean, 45.4; 95 % CI, 43.0 to 47.8). Meta-regression showed LV end-diastolic diameter as a significant determinant of variation of longitudinal strain. Longitudinal systolic strain rate was significantly determined by age and radial strain was influenced by the type of vendor used. Conclusion: The systematic review showed subclinical LV dysfunction in children with CoA before and after correction. However, since most of the patients were operated at an older age and had preserved LV EF, the effect of early intervention on LV function was only speculated. Our children with CoA who were operated at an earlier age showed LV subclinical dysfunction even at medium- term after intervention while the AoSA returned to normal shortly after intervention. Lower longitudinal strain values were found in patients with LV dysfunction (LV EF <50%) before intervention and BAV. Finally, normal range values for strain and strain rate have been established and seem to be influenced by patients’ age, LV end-diastolic diameter and vendor used.

Cardiac magnetic resonance (CMR) imaging is the gold standard imaging technique for assessment of ventricular dimensions and function. CMR also allows assessment of ventricular deformation but this requires additional imaging sequences and time consuming post processing which has limited its widespread use. A novel CMR analysis software package, ‘feature tracking’ (Tom Tec, Germany) can measure ventricular deformation directly from cine CMR images. This thesis seeks to further our understanding of the feasibility of feature tracking to assess myocardial deformation and volumetric measures. Chapter 3 validates normal ranges for deformation parameters and compares values against traditional tagging measures. The work identifies global circumferential strain measures as being the most reproducible. In chapters 4 and 5, feature tracking values for left and right ventricular strain are compared with echocardiography derived speckle tracking indices of deformation. For left ventricular (LV) parameters, circumferential and longitudinal strain are most consistent and for the right ventricular (RV) measures, assessment of free wall strain using feature tracking shows promise and with modifications in algorithms is likely to further improve in the future. Chapter 6 assesses the ability of feature tracking to measure diastolic function. The results show that radial diastolic velocities and longitudinal diastolic strain rates can predict diastolic dysfunction (as diagnosed by echocardiography) with acceptable levels of sensitivity and specificity, particularly when used in combination. 11 The use of feature tracking to provide automated measures of ventricular volumes, mass and ejection fraction is assessed in chapter 7. Feature tracking in this context shows acceptable correlation but poor absolute agreement with manual contouring and further adjustments to algorithms is necessary to improve its accuracy. This work offers insights into the use of feature tracking for the assessment of ventricular deformation parameters. It is a technique with advantages over CMR tagging methods and given the speed of post processing has the potential to become the CMR preferred assessment for strain quantification in the future.

INTRODUÇÃO: A deformação miocárdica e a rotação ventricular têm sido amplamente empregadas na avaliação segmentar e global da função cardíaca no contexto clínico das diversas patologias cardiológicas. São escassos os estudos científicos reportados na literatura que analisaram o impacto do treinamento físico sobre o parâmetros de avaliação da dinâmica de contração do ventrículo esquerdo em coronariopatas inseridos em programas de reabilitação cardíaca. OBJETIVO: O presente estudo analisou a influência do treinamento aeróbico na capacidade física e nos parâmetros de avaliação do remodelamento ventricular e da mecânica de contração do ventrículo esquerdo em pacientes com infarto do miocárdio. MATERIAIS E MÉTODOS: Foram prospectivamente investigados 30 pacientes, 55,1 ± 8,9 anos, acometidos por infarto do miocárdio de parede anterior, aleatorizados em três grupos: grupo treinamento intervalado (GTI) (n=10), grupo treinamento moderado (GTM) (n=10) e grupo controle (GC) (n=10). Antes e após as 12 semanas de seguimento clínico, os pacientes realizaram avaliação cardiológica, eletrocardiograma, teste cardiopulmonar de exercício e ressonância magnética cardíaca. Os grupos treinados realizaram treinamento aeróbico supervisionado, em esteira ergométrica, aplicando-se duas intensidades distintas. A análise estatística foi realizada por meio de modelo linear de efeitos mistos (aleatórios e fixos). RESULTADOS: Observou-se diferença estatisticamente significante no consumo de oxigênio (VO2) pico do GTI (21,9±5,6, p=0.01) e do GTM (21,6±4,5, p=0.02) comparativamente ao GC (17,1±4,6 ml/kg/min) e, também, diferença estatisticamente significante na ventilação-minuto (VM) do GTI (72,2±21,9, p=0.001) e do GTM (68,6±15,5, p=0.004) comparativamente ao GC (48,4±15,9 L/min) na avaliação intergrupos, após o período de seguimento clínico. Não houve mudança estatisticamente significante dos volumes cavitários, da massa e da fração de ejeção do ventrículo esquerdo nos três grupos, tanto na análise intragrupo quanto na intergrupos, após o seguimento clínico. Observou-se aumento estatisticamente significante do strain radial basal (STRAD_B) somente no GC de 57,4±16,6 para 84,1±30,9%, p=0.009, na análise intragrupo. Observou-se diferença estatisticamente significante no STRAD_B do GTI (58,6±18,8, p=0.01) e do GTM (60,4±25,5, p=0.01) comparativamente ao GC (84,1±30,9%) na avaliação intergrupos, após o período de seguimento clínico. CONCLUSÃO: O treinamento aeróbico propiciou a manutenção do status da capacidade funcional, e não determinou remodelamento ventricular adverso, nos grupos treinados comparativamente ao GC. O comportamento distinto do strain radial basal, entre os grupos treinados e o GC, possivelmente reflete uma adaptação do miocárdio pósinfarto relacionada ao treinamento aeróbico. / INTRODUCTION: The myocardial deformation and the ventricular rotation have been widely used in the evaluation of the segment and overall cardiac function in the clinical setting of the various cardiac pathologies. There are few scientific studies reported in the literature that it analyzed the impact of the physical training on the assessment parameters of the left ventricular contraction dynamics in the coronary patients inserted in cardiac rehabilitation programs. OBJECTIVE: This study examined the influence of the aerobic training in the physical fitness and in the evaluation parameters of the ventricular remodeling and of the left ventricular contraction mechanics in patients with myocardial infarction. MATERIALS AND METHODS: Thirty patients were prospectively investigated, 55.1 ± 8.9 years, affected by myocardial anterior wall infarction, randomized into three groups: interval training group (GTI) (n = 10), moderate training group (GTM) (n = 10) and control group (GC) (n = 10). Before and after 12 weeks of the follow-up, the patients underwent cardiac assessment, ECG, cardiopulmonary exercise test and cardiac magnetic resonance imaging. The trained groups performed the aerobic training supervised in treadmill, applying two different intensities. The statistical analysis was performed using a linear mixed effects model (random and fixed). RESULTS: There was a statistically significant difference in the oxygen uptake (VO2) peak of the GTI (21.9 ± 5.6, p = 0.01) and of the GTM (21.6 ± 4.5, p = 0.02) compared to the GC (17.1 ± 4.6 ml / kg / min), and an also statistically significant difference in the minute ventilation (VM) of the GTI (72.2 ± 21.9, p = 0.001) and of the GTM (68.6 ± 15.5, p = 0.004) compared to the GC (48.4 ± 15.9 L / min) in the intergroup assessment, after the follow-up period. There was no significant change in chamber volumes, mass and left ventricular ejection fraction in the three groups, both in the intragroup and intergroup analysis, after the follow-up. There was a statistically significant increase of the basal radial strain (STRAD_B) only in the GC 57.4 ± 16.6 to 84.1 ± 30.9%, p = 0.009, in the intragroup analysis. There was a statistically significant difference of the STRAD_B in the GTI (58.6 ± 18.8, p = 0.01) and in the GTM (60.4 ± 25.5, p = 0.01) compared to the GC (84.1 ± 30.9 %) in the intergroup evaluation, after the follow-up period. CONCLUSION: The aerobic training provided a maintenance of the status of the physical fitness, and it has not determined an adverse ventricular remodeling, in the trained groups compared to the GC. The different behavior of the basal radial strain between the trained groups and the GC possibly reflects a post-myocardial infarction adaptation related to the aerobic training.

INTRODUÇÃO: A deformação miocárdica e a rotação ventricular têm sido amplamente empregadas na avaliação segmentar e global da função cardíaca no contexto clínico das diversas patologias cardiológicas. São escassos os estudos científicos reportados na literatura que analisaram o impacto do treinamento físico sobre o parâmetros de avaliação da dinâmica de contração do ventrículo esquerdo em coronariopatas inseridos em programas de reabilitação cardíaca. OBJETIVO: O presente estudo analisou a influência do treinamento aeróbico na capacidade física e nos parâmetros de avaliação do remodelamento ventricular e da mecânica de contração do ventrículo esquerdo em pacientes com infarto do miocárdio. MATERIAIS E MÉTODOS: Foram prospectivamente investigados 30 pacientes, 55,1 ± 8,9 anos, acometidos por infarto do miocárdio de parede anterior, aleatorizados em três grupos: grupo treinamento intervalado (GTI) (n=10), grupo treinamento moderado (GTM) (n=10) e grupo controle (GC) (n=10). Antes e após as 12 semanas de seguimento clínico, os pacientes realizaram avaliação cardiológica, eletrocardiograma, teste cardiopulmonar de exercício e ressonância magnética cardíaca. Os grupos treinados realizaram treinamento aeróbico supervisionado, em esteira ergométrica, aplicando-se duas intensidades distintas. A análise estatística foi realizada por meio de modelo linear de efeitos mistos (aleatórios e fixos). RESULTADOS: Observou-se diferença estatisticamente significante no consumo de oxigênio (VO2) pico do GTI (21,9±5,6, p=0.01) e do GTM (21,6±4,5, p=0.02) comparativamente ao GC (17,1±4,6 ml/kg/min) e, também, diferença estatisticamente significante na ventilação-minuto (VM) do GTI (72,2±21,9, p=0.001) e do GTM (68,6±15,5, p=0.004) comparativamente ao GC (48,4±15,9 L/min) na avaliação intergrupos, após o período de seguimento clínico. Não houve mudança estatisticamente significante dos volumes cavitários, da massa e da fração de ejeção do ventrículo esquerdo nos três grupos, tanto na análise intragrupo quanto na intergrupos, após o seguimento clínico. Observou-se aumento estatisticamente significante do strain radial basal (STRAD_B) somente no GC de 57,4±16,6 para 84,1±30,9%, p=0.009, na análise intragrupo. Observou-se diferença estatisticamente significante no STRAD_B do GTI (58,6±18,8, p=0.01) e do GTM (60,4±25,5, p=0.01) comparativamente ao GC (84,1±30,9%) na avaliação intergrupos, após o período de seguimento clínico. CONCLUSÃO: O treinamento aeróbico propiciou a manutenção do status da capacidade funcional, e não determinou remodelamento ventricular adverso, nos grupos treinados comparativamente ao GC. O comportamento distinto do strain radial basal, entre os grupos treinados e o GC, possivelmente reflete uma adaptação do miocárdio pósinfarto relacionada ao treinamento aeróbico. / INTRODUCTION: The myocardial deformation and the ventricular rotation have been widely used in the evaluation of the segment and overall cardiac function in the clinical setting of the various cardiac pathologies. There are few scientific studies reported in the literature that it analyzed the impact of the physical training on the assessment parameters of the left ventricular contraction dynamics in the coronary patients inserted in cardiac rehabilitation programs. OBJECTIVE: This study examined the influence of the aerobic training in the physical fitness and in the evaluation parameters of the ventricular remodeling and of the left ventricular contraction mechanics in patients with myocardial infarction. MATERIALS AND METHODS: Thirty patients were prospectively investigated, 55.1 ± 8.9 years, affected by myocardial anterior wall infarction, randomized into three groups: interval training group (GTI) (n = 10), moderate training group (GTM) (n = 10) and control group (GC) (n = 10). Before and after 12 weeks of the follow-up, the patients underwent cardiac assessment, ECG, cardiopulmonary exercise test and cardiac magnetic resonance imaging. The trained groups performed the aerobic training supervised in treadmill, applying two different intensities. The statistical analysis was performed using a linear mixed effects model (random and fixed). RESULTS: There was a statistically significant difference in the oxygen uptake (VO2) peak of the GTI (21.9 ± 5.6, p = 0.01) and of the GTM (21.6 ± 4.5, p = 0.02) compared to the GC (17.1 ± 4.6 ml / kg / min), and an also statistically significant difference in the minute ventilation (VM) of the GTI (72.2 ± 21.9, p = 0.001) and of the GTM (68.6 ± 15.5, p = 0.004) compared to the GC (48.4 ± 15.9 L / min) in the intergroup assessment, after the follow-up period. There was no significant change in chamber volumes, mass and left ventricular ejection fraction in the three groups, both in the intragroup and intergroup analysis, after the follow-up. There was a statistically significant increase of the basal radial strain (STRAD_B) only in the GC 57.4 ± 16.6 to 84.1 ± 30.9%, p = 0.009, in the intragroup analysis. There was a statistically significant difference of the STRAD_B in the GTI (58.6 ± 18.8, p = 0.01) and in the GTM (60.4 ± 25.5, p = 0.01) compared to the GC (84.1 ± 30.9 %) in the intergroup evaluation, after the follow-up period. CONCLUSION: The aerobic training provided a maintenance of the status of the physical fitness, and it has not determined an adverse ventricular remodeling, in the trained groups compared to the GC. The different behavior of the basal radial strain between the trained groups and the GC possibly reflects a post-myocardial infarction adaptation related to the aerobic training.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / O auxÃlio ao diagnÃstico atravÃs da visualizaÃÃo de imagens mÃdicas vÃm sendo utilizado em diversas Ãreas da Medicina tais como pneumologia, cardiologia, traumatologia, neurologia, dentre outras. Na Ãrea da cardiologia, vÃrias aplicaÃÃes clÃnicas tÃm sido propostas para a anÃlise de doenÃas cardÃacas atravÃs da quantificaÃÃo e avaliaÃÃo da dessincronia ventricular esquerda durante a deformaÃÃo do mÃsculo cardÃaco (miocÃrdio). Existem, atualmente, duas tÃcnicas utilizadas na aferiÃÃo da deformaÃÃo miocÃrdica em duas dimensÃes: Doppler Tecidual (DT) e Strain 2D (St2D). A primeira tÃcnica possui desvantagens quanto à dependÃncia do Ãngulo de insonaÃÃo do transdutor durante o exame ecocardiogrÃfico, diminuindo a chance de reprodutibilidade do resultado das mediÃÃes entre especialistas. A segunda tÃcnica, recentemente introduzida e tambÃm chamada de Speckle Tracking, consiste no acompanhamento de marcadores acÃsticos naturais existentes na imagem produzida pelo ultrassom. Neste sentido, vÃ-se a importÃncia do estudo de tÃcnicas para rastrear esses marcadores acÃsticos. A presente dissertaÃÃo realiza uma anÃlise comparativa entre oito algoritmos de estimaÃÃo de deslocamento baseados na tÃcnica de Casamento de Blocos (CB) e trÃs algoritmos baseados na tÃcnica de Fluxo Ãptico (FO), que sÃo as duas atuais tÃcnicas amplamente citadas na literatura. A anÃlise à realizada mediante vÃdeos sintÃticos e vÃdeos mÃdicos de exames ecocardiogrÃficos. A avaliaÃÃo das tÃcnicas em vÃdeos sintÃticos à realizada quanto à trajetÃria e à deformaÃÃo. Jà a avaliaÃÃo em vÃdeos de exames ecocardiogrÃficos à realizada quanto Ãs curvas e taxas de deformaÃÃo. Na anÃlise da trajetÃria sÃo aplicadas duas mÃtricas de avaliaÃÃo das tÃcnicas: correlaÃÃo mÃdia e erro quadrÃtico mÃdio. Para a anÃlise das curvas e das taxas de deformaÃÃo a mÃtrica usada à o valor do erro quadrÃtico mÃdio em relaÃÃo à deformaÃÃo global (global strain) do miocÃrdio. Os resultados indicam que o desempenho idÃntico de alguns estimadores de deslocamento os reduzem de oito para seis algoritmos. A tÃcnica de CB mostra-se viÃvel para o rastreamento de marcas acÃsticas mas à dependente das dimensÃes adotadas nos blocos. Em relaÃÃo Ãs tÃcnicas de FO, o algoritmo de Lucas e Kanade Piramidal à o que obtÃm melhor resultado nos testes realizados, produzindo curvas de deformaÃÃo global com erro mÃdio de 0,47%, enquanto os valores de erro dos outros algoritmos de FO estÃo em torno de 10%. No caso, os erros dos estimadores de CB variam de 1% a 16%. / Aided diagnosis by visualization of medical images has been used in several medical fields such as pulmonology, cardiology, traumatology, neurology, and others. In cardiology, several clinical applications have been proposed for the analysis of heart disease by quantification and evaluation of ventricular dyssynchrony during deformation of the heart muscle (myocardium). There are currently two techniques used in the measurement of myocardial deformation in two dimensions: Tissue Doppler and 2D Strain. The first technique has drawbacks regarding the dependence on the angle of insonation of the transducer during the echocardiographic examination, which reduce the chance of reproducibility of measurements among experts. The second technique, recently introduced and also called Speckle Tracking, consists of tracking the natural acoustic markers in the image produced by ultrasound. In this sense we see the importance of studying techniques to track these acoustic markers. This thesis performs a comparative analysis of eight algorithms from time-delay estimators based on the block matching technique and three algorithms based on the optical flow technique, which are the two current techniques widely presented in the literature. The analysis is performed using synthetic videos and medical videos from echocardiographic examinations. The evaluation of the techniques in synthetic videos is performed on the trajectory and deformation. The assessment in echocardiographic videos is held regarding the strain curves and strain rates. In the analysis of the trajectory are applied two metrics for evaluating techniques: mean correlation and mean square error. For the analysis of strain curves and of strain rate the measure used is the value of the mean square error relative to global strain of myocardium. The results indicate that the identical performance of some estimators reduce the time-delay estimators from eight to six algorithms. The block matching technique appears to be a viable technique for tracking acoustic marks but is dependent on the dimensions adopted in the blocks. Regarding optical flow techniques, the Lucas and Kanade Pyramidal algorithm is the one which gets the best results in the tests performed herein and produce global strain curves average error of 0.47 %, while the error values of the other optical flow algorithms are around 10 %. In case, the block matching time-delay estimators errors vary from 1% to 16%.