Cardiac resynchronization therapy (CRT) has recently emerged as an effective treatment option for heart failure patients with dyssynchrony. Patients have traditionally been chosen for CRT based on a prolonged QRS interval. However, this selection method is far from ideal, as approximately 30% of those receiving CRT do not show any clinical improvement. Tissue Doppler imaging (TDI) suggests that one of the best predictors of response to CRT is the underlying level of mechanical dyssynchrony in the myocardial wall prior to CRT. As a result, there has been growing interest in direct imaging of the myocardial wall. Because myocardial contraction is a complex, three-dimensional movement, providing an accurate picture of myocardial wall motion can be challenging. Echocardiography initially emerged as the modality of choice, but the long list of limitations (limited echocardiographic windows, one direction of motion, poor reproducibility) has fostered interest in exploring the use of MR for myocardial wall imaging. Although MR presents some unique drawbacks (expensive equipment, longer imaging times), it is able to overcome many of the limitations of TDI. In particular, Phase Velocity Mapping (MR PVM) can provide a complete, three-directional description of motion throughout the entire myocardial wall at high spatial and temporal resolution. The overall goal of this project was to develop a patient-selection method for CRT based on myocardial wall velocities acquired with MR PVM. First the image acquisition and post-processing protocols for MR PVM imaging of myocardial tissue were developed. A myocardial motion phantom was used to verify the accuracy of, and optimize the acquisition parameters for, the developed MR PVM sequence. Excellent correlation was demonstrated between longitudinal myocardial velocity curves acquired with the optimized MR PVM sequence and Tissue Doppler velocities. A database describing the normal myocardial contraction pattern was constructed. A small group of dyssynchrony patients was compared to the normal database, and several areas of delayed contraction were identified in the patients. Furthermore, significantly higher levels of dyssynchrony were detected in the patients than the normal volunteers. Finally, a method for computing transmural, endocardial, and epicardial, radial strains and strain rates from MR PVM velocity data was developed

Introdução: A terapia de ressincronização cardíaca (TRC) tem se mostrado como um tratamento eficaz no tratamento de pacientes com insuficiência cardíaca (IC) grave e distúrbio da condução ventricular. A ecocardiografia tridimensional (Eco 3D) consiste em uma nova modalidade diagnóstica com resultados promissores para a identificação da dissincronia cardíaca e avaliação dos resultados da TRC. Objetivos: Estudar os efeitos da TRC no remodelamento reverso do ventrículo esquerdo (VE), em pacientes com miocardiopatia não isquêmica, insuficiência cardíaca e distúrbio da condução intraventricular, por meio da ecocardiografia tridimensional em tempo real. Métodos: De janeiro de 2007 a junho de 2009, foram avaliados 24 pacientes com miocardiopatia dilatada não isquêmica, IC classe funcional (CF) III ou IV (NYHA), com tratamento medicamentoso otimizado, QRS > 120 ms ao eletrocardiograma, e fração de ejeção do ventrículo esquerdo (FEVE) < 0,35 submetidos à TRC. Os pacientes foram avaliados antes, três e seis meses após TRC pela CF (NYHA), qualidade de vida pelo escore de Minnesota (MLHFQ), eletrocardiograma (intervalo PR e duração do QRS), ecocardiograma bidimensional (volumes diastólico VDVE, e sistólico VSVE, do ventrículo esquerdo, fração de ejeção ventricular esquerda - FEVE), Doppler tecidual (TDI) (avaliação da dissincronia cardíaca) e análise tridimensional (VDVE, VSVE, FEVE e dissincronia pela análise do SDI systolic dyssynchrony index). Foi considerado remodelamento reverso redução > 15% do VSVE após a TRC. As diferenças das médias das variáveis contínuas foram analisadas com o teste T não pareado, entre os grupos respondedor e não respondedor, depois de satisfeita a condição de normalidade. Antes da TRC, foi realizada uma análise univariada das características clínicas, eletrocardiográficas e ecocardiográficas para a construção de um modelo de regressão logística. Resultados: 9/24(38%) dos pacientes analisados apresentaram remodelamento ventricular reverso após TRC. O grupo respondedor apresentou menores volumes ventriculares (VDVE: 230 + 35 ml vs 316 + 10 ml, p = 0,045; VSVE: 178 + 30 ml vs 238 + 10 ml, p = 0,047), avaliados pelo método de Simpson, além de maior dissincronia cardíaca, avaliada pelo Eco 3D (SDI:13 + 3% vs 9 + 3%, p = 0,005) e pelo TDI (138 + 31 ms vs 102 + 37 ms, p = 0,026). Após a análise de regressão logística, o SDI (SDI > 11%) foi o único fator independente na predição de remodelamento reverso, seis meses após a TRC (sensibilidade:0,78; especificidade:0,79). Conclusões: O Eco 3D foi eficaz na detecção do remodelamento reverso do VE após a TRC, por meio da detecção da redução dos volumes ventriculares esquerdos (VDVE, VSVE) e da melhora da FEVE. O SDI foi o único preditor independente de remodelamento reverso após a TRC. Apresentaram menor taxa de resposta seis meses após a TRC, os pacientes com maiores volumes ventriculares esquerdos e menor fração de ejeção ventricular esquerda. A TRC melhorou a CF (NYHA) de IC e a qualidade de vida pelo escore de Minnesota / Introduction: Cardiac resynchronization therapy (CRT) consists of an effective treatment for patients with severe heart failure and ventricular conduction disturbance. Three dimensional echocardiography (3D Echo) is a new diagnostic modality with promising results in the identification of cardiac dyssynchrony and for the evaluation of CRT results. Objectives: To evaluate the effects of CRT in the left ventricular (LV) reverse remodeling in patients with non ischemic dilated myocardiopathy, heart failure and intraventricular conduction disturbance by using three dimensional echocardiography. Methods: From January, 2007 to June, 2009, twenty-four consecutive patients with heart failure, sinus rhythm, QRS > 120 ms, and Functional Class III or IV (NYHA), despite optimized medical treatment and left ventricular ejection fraction (LVEF) < 0,35, underwent CRT. All patients were assessed regarding Functional Class (NYHA), and the quality of life was evaluated using the Minnesota Living with Heart Failure Questionnaire (MLHFQ). All patients were submitted to an electrocardiogram, two dimensional echocardiography (2D Echo) including the evaluation of cardiac dyssynchrony by Tissue Doppler Imaging (TDI) and 3D Echo (SDI - systolic dyssynchrony index), before, three and six months after CRT. Left ventricular reverse remodeling was defined as a reduction of at least 15% of the left ventricular systolic volume (LVSV) after CRT. The difference between the mean of the continuous variables were compared by students T test, after being tested for normality. Before CRT, it was performed a univariate analysis of clinical, electrocardiographic and echocardiographic baseline characteristics of the patients for the construction of a logistic regression model. Results: 9/24 (38%) of the patients presented with left ventricular reverse remodeling six months after CRT. Patients who presented LV reverse remodeling had smaller left ventricular volumes estimated by Simpsons rule (LV diastolic volume (LVDV): 230 + 35 ml vs 316 + 10 ml, p = 0,045; LVSV: 178 + 30 ml vs 238 + 10 ml, p = 0,047) and greater cardiac dyssynchrony detected by 3D Echo (SDI: 13 + 3% vs 9 + 3%, p = 0,005) and by TDI (138 + 31 ms vs 102 + 37 ms, p = 0,026). After logistic regression analysis, the best predictors of left ventricular reverse remodeling after CRT were the cardiac dyssynchrony indexes evaluated by TDI (twelve segments) and SDI, but SDI (SDI > 11%) was the only independent factor in the prediction of left ventricular reverse remodeling six months after CRT (sensitivity of 0,78 and specificity of 0,79). Conclusions: 3D Echo was effective in the detection of left ventricular reverse remodeling after CRT, by detecting the reduction in left ventricular volumes (LVDV, LVSV) and the increase in LVEF. SDI was the only independent predictor of LV reverse remodeling after CRT. Patients with larger LV volumes, and smaller LVEF were more prone to not respond six months after CRT. CRT improved Functional Class (NYHA) and quality of life evaluated by MLHFQ

Introdução: A terapia de ressincronização cardíaca (TRC) tem se mostrado como um tratamento eficaz no tratamento de pacientes com insuficiência cardíaca (IC) grave e distúrbio da condução ventricular. A ecocardiografia tridimensional (Eco 3D) consiste em uma nova modalidade diagnóstica com resultados promissores para a identificação da dissincronia cardíaca e avaliação dos resultados da TRC. Objetivos: Estudar os efeitos da TRC no remodelamento reverso do ventrículo esquerdo (VE), em pacientes com miocardiopatia não isquêmica, insuficiência cardíaca e distúrbio da condução intraventricular, por meio da ecocardiografia tridimensional em tempo real. Métodos: De janeiro de 2007 a junho de 2009, foram avaliados 24 pacientes com miocardiopatia dilatada não isquêmica, IC classe funcional (CF) III ou IV (NYHA), com tratamento medicamentoso otimizado, QRS > 120 ms ao eletrocardiograma, e fração de ejeção do ventrículo esquerdo (FEVE) < 0,35 submetidos à TRC. Os pacientes foram avaliados antes, três e seis meses após TRC pela CF (NYHA), qualidade de vida pelo escore de Minnesota (MLHFQ), eletrocardiograma (intervalo PR e duração do QRS), ecocardiograma bidimensional (volumes diastólico VDVE, e sistólico VSVE, do ventrículo esquerdo, fração de ejeção ventricular esquerda - FEVE), Doppler tecidual (TDI) (avaliação da dissincronia cardíaca) e análise tridimensional (VDVE, VSVE, FEVE e dissincronia pela análise do SDI systolic dyssynchrony index). Foi considerado remodelamento reverso redução > 15% do VSVE após a TRC. As diferenças das médias das variáveis contínuas foram analisadas com o teste T não pareado, entre os grupos respondedor e não respondedor, depois de satisfeita a condição de normalidade. Antes da TRC, foi realizada uma análise univariada das características clínicas, eletrocardiográficas e ecocardiográficas para a construção de um modelo de regressão logística. Resultados: 9/24(38%) dos pacientes analisados apresentaram remodelamento ventricular reverso após TRC. O grupo respondedor apresentou menores volumes ventriculares (VDVE: 230 + 35 ml vs 316 + 10 ml, p = 0,045; VSVE: 178 + 30 ml vs 238 + 10 ml, p = 0,047), avaliados pelo método de Simpson, além de maior dissincronia cardíaca, avaliada pelo Eco 3D (SDI:13 + 3% vs 9 + 3%, p = 0,005) e pelo TDI (138 + 31 ms vs 102 + 37 ms, p = 0,026). Após a análise de regressão logística, o SDI (SDI > 11%) foi o único fator independente na predição de remodelamento reverso, seis meses após a TRC (sensibilidade:0,78; especificidade:0,79). Conclusões: O Eco 3D foi eficaz na detecção do remodelamento reverso do VE após a TRC, por meio da detecção da redução dos volumes ventriculares esquerdos (VDVE, VSVE) e da melhora da FEVE. O SDI foi o único preditor independente de remodelamento reverso após a TRC. Apresentaram menor taxa de resposta seis meses após a TRC, os pacientes com maiores volumes ventriculares esquerdos e menor fração de ejeção ventricular esquerda. A TRC melhorou a CF (NYHA) de IC e a qualidade de vida pelo escore de Minnesota / Introduction: Cardiac resynchronization therapy (CRT) consists of an effective treatment for patients with severe heart failure and ventricular conduction disturbance. Three dimensional echocardiography (3D Echo) is a new diagnostic modality with promising results in the identification of cardiac dyssynchrony and for the evaluation of CRT results. Objectives: To evaluate the effects of CRT in the left ventricular (LV) reverse remodeling in patients with non ischemic dilated myocardiopathy, heart failure and intraventricular conduction disturbance by using three dimensional echocardiography. Methods: From January, 2007 to June, 2009, twenty-four consecutive patients with heart failure, sinus rhythm, QRS > 120 ms, and Functional Class III or IV (NYHA), despite optimized medical treatment and left ventricular ejection fraction (LVEF) < 0,35, underwent CRT. All patients were assessed regarding Functional Class (NYHA), and the quality of life was evaluated using the Minnesota Living with Heart Failure Questionnaire (MLHFQ). All patients were submitted to an electrocardiogram, two dimensional echocardiography (2D Echo) including the evaluation of cardiac dyssynchrony by Tissue Doppler Imaging (TDI) and 3D Echo (SDI - systolic dyssynchrony index), before, three and six months after CRT. Left ventricular reverse remodeling was defined as a reduction of at least 15% of the left ventricular systolic volume (LVSV) after CRT. The difference between the mean of the continuous variables were compared by students T test, after being tested for normality. Before CRT, it was performed a univariate analysis of clinical, electrocardiographic and echocardiographic baseline characteristics of the patients for the construction of a logistic regression model. Results: 9/24 (38%) of the patients presented with left ventricular reverse remodeling six months after CRT. Patients who presented LV reverse remodeling had smaller left ventricular volumes estimated by Simpsons rule (LV diastolic volume (LVDV): 230 + 35 ml vs 316 + 10 ml, p = 0,045; LVSV: 178 + 30 ml vs 238 + 10 ml, p = 0,047) and greater cardiac dyssynchrony detected by 3D Echo (SDI: 13 + 3% vs 9 + 3%, p = 0,005) and by TDI (138 + 31 ms vs 102 + 37 ms, p = 0,026). After logistic regression analysis, the best predictors of left ventricular reverse remodeling after CRT were the cardiac dyssynchrony indexes evaluated by TDI (twelve segments) and SDI, but SDI (SDI > 11%) was the only independent factor in the prediction of left ventricular reverse remodeling six months after CRT (sensitivity of 0,78 and specificity of 0,79). Conclusions: 3D Echo was effective in the detection of left ventricular reverse remodeling after CRT, by detecting the reduction in left ventricular volumes (LVDV, LVSV) and the increase in LVEF. SDI was the only independent predictor of LV reverse remodeling after CRT. Patients with larger LV volumes, and smaller LVEF were more prone to not respond six months after CRT. CRT improved Functional Class (NYHA) and quality of life evaluated by MLHFQ

L'objectif de ce travail était de mieux appréhender les mécanismes impliqués dans la réponse à la resynchronisation biventriculaire (BIV) en insistant sur la caractérisation du substrat électrique éligible à la thérapie et l'intérêt de la resynchronisation électrique. Nous avons démontré qu'il existe une relation forte entre l'asynchronisme électrique de base défini tant par l'ECG de surface que par cartographie détaillée de l'activation ventriculaire (ECM) et la réponse hémodynamique à la stimulation BIV. Par rapport à l'ECG de surface, l'ECM permet une caractérisation plus fine de l'asynchronisme électrique ventriculaire avec une meilleure prédiction de la réponse clinique à la stimulation BIV. La présence d'un asynchronisme de base minimum, en particulier d'un retard d'activation ventriculaire gauche (VG) par rapport au ventricule droit (typiquement >SOms), est un prérequis à l'efficacité de la thérapie. Les patients avec bloc de branche gauche présentent un haut degré d'asynchronisme et la stimulation BIV agit sur ce substrat par resynchronisation de l'activation électrique. A contrario, la stimulation BIV dégrade la séquence d'activation ainsi que l'hémodynamique des patients à QRS fins (dyssynchronie iatrogène). Les patients présentant un trouble de conduction aspécifique présentent des degrés variables d'asynchronie électrique et en conséquence des réponses contrastées à la stimulation BIV. De même, l'analyse ECM de l'asynchronisme des patients chroniquement stimulés sur le ventricule droit a permis de mettre en évidence des degrés variables de retard d'activation du VG. Si la resynchronisation électrique est garante d'une amélioration de la fonction cardiaque, d'autres mécanismes sont impliqués telle la redistribution du travail segmentaire au sein du myocarde ventriculaire. L'efficacité de la stimulation mono-VG implique une participation accrue du ventricule droit au travail global (interaction ventriculaire). / We aimed to characterize the electrical substrate amenable to biventricular pacing (BVP) and to assess the actual value of electrical resynchronization. We showed, both with respect to surface ECG and detailed ventricular electrocardiographic mapping (ECM), a strong relationship between the baseline electrical dyssnchrony and the hemodynamic response to BIV pacing. Compared with standard ECG, ECM allows a more detailed analysis of the ventricular dyssynchrony and better predicts clinical outcomes after BVP. A minimal amount of electrical dyssynchrony, in particular a sufficient LV activation delay relative to right ventricular activation, is a prerequisite to the hemodynamic response to BVP. Due to their advanced electrical dyssynchrony, patients with left bundle branch block present potential for BVP positive response which acts by electrical resynchronization. Conversely, BVP worsens the electrical activation (iatrogenic dyssynchrony) and hemodynamics in patients with narrow QRS suffering from insufficient electrical dyssynchrony at baseline. Patients with unspecified conduction disorders show variable levels of electrical dyssynchrony and as a consequence mixed results to BVP. Similarly, ECM reveals a variable degree of left ventricular activation delay in patients chronically paced in the right ventricle. Beside the electrical resynchronization, other mechanisms are involved in the cardiac pump function improvement such as the redistribution of the mechanical work over the right and left ventricles. Through ventricular interaction, the RV myocardium importantly contributes to the improvement in LV pump function induced by single site LV pacing.

Cette thèse porte sur la caractérisation cardiaque, qui représente un enjeu méthodologique et clinique important, à la fois pour améliorer le diagnostic des pathologies et optimiser les moyens de traitement. Des méthodes de recalage et de fusion de données sont proposées pour amener dans un même référentiel des images IRM, scanner, échographiques et électro-anatomiques et ainsi décrire le cœur suivant des caractéristiques anatomiques, électriques, mécaniques et tissulaires. Les méthodes proposées pour recaler des données multimodales reposent sur deux processus principaux : l'alignement temporel et le recalage spatial. Les dimensions temporelles des images considérées sont mises en synchronisées par une méthode de déformation temporelle dynamique adaptative. Celle-ci permet de compenser les modifications temporelles non-linéaires entre les différentes acquisitions. Pour le recalage spatial, des méthodes iconiques ont été développées pour corriger les artefacts de mouvements dans les séquences ciné-IRM, pour recaler les séquences ciné-IRM avec les séquences d'IRM de rehaussement tardif et pour recaler les ciné-IRM avec les images scanner. D'autre part, une méthode basée contours, développée dans un précédent travail, a été améliorée pour prendre en compte des acquisitions échographiques multi-vues. Ces méthodes ont été évaluées sur données réelles pour sélectionner les métriques les plus adaptées et pour quantifier les performances des approches iconiques et pour estimer la précision du recalage entre échographies et ciné-IRM. Ces méthodes sont appliquées à la caractérisation de cardiomyopathies hypertrophiques (CMH) et d'asynchronismes cardiaques. Pour la CMH, l'objectif était de mieux interpréter les données échographiques par la fusion de l'information de fibrose issue de l'IRM de rehaussement tardif avec l'information mécanique issue de l'échographie de speckle tracking. Cette analyse a permis d'évaluer le strain régional en tant qu'indicateur de la présence locale de fibrose. Concernant l'asynchronisme cardiaque, nous avons établi une description du couplage électromécanique local du ventricule gauche par la fusion de données échographiques, électro-anatomiques, scanner et, dans les cas appropriés, d'IRM de rehaussement tardif. Cette étude de faisabilité ouvre des perspectives pour l'utilisation de nouveaux descripteurs pour la sélection des sites de stimulation optimaux pour la thérapie de resynchronisation cardiaque. / This work concerns cardiac characterization, a major methodological and clinical issue, both to improve disease diagnostic and to optimize its treatment. Multisensor registration and fusion methods are proposed to bring into a common referential data from cardiac magnetic resonance (CMRI), dynamic cardiac X-ray computed tomography (CT), speckle tracking echocardiography (STE) and electro-anatomical mappings of the inner left ventricular chamber (EAM). These data is used to describe the heart by its anatomy, electrical and mechanical function, and the state of the myocardial tissue. The methods proposed to register the multimodal datasets rely on two main processes: temporal registration and spatial registration. The temporal dimensions of input data (images) are warped with an adaptive dynamic time warping (ADTW) method. This method allowed to handle the nonlinear temporal relationship between the different acquisitions. Concerning the spatial registration, iconic methods were developed, on the one hand, to correct for motion artifacts in cine acquisition, to register cine-CMRI and late gadolinium CMRI (LGE-CMRI), and to register cine-CMRI with dynamic CT. On the other hand, a contour-based method developed in a previous work was enhanced to account for multiview STE acquisitions. These methods were evaluated on real data in terms of the best metrics to use and of the accuracy of the iconic methods, and to assess the STE to cine-CMRI registration. The fusion of these multisensor data enabled to get insights about the diseased heart in the context of hypertrophic cardiomyopathy (HCM) and cardiac asynchronism. For HCM, we aimed to improve the understanding of STE by fusing fibrosis from LGE-CMRI with strain from multiview 2D STE. This analysis allowed to assess the significance of regional STE strain as a surrogate of the presence of regional myocardial fibrosis. Concerning cardiac asynchronism, we aimed to describe the intra-segment electro-mechanical coupling of the left ventricle using fused data from STE, EAM, CT and, if relevant, from LGE-CMRI. This feasibility study provided new elements to select the optimal sites for LV stimulation.

Introdução: O bloqueio atrioventricular congênito isolado (BAVCi) é raro e tem múltiplas apresentações clínicas. O implante de marca-passo cardíaco permanente (MP) é o tratamento de escolha, resultando em evolução clínica satisfatória para a maioria dos casos, porém, aproximadamente 10% deles apresentam remodelamento ventricular e insuficiência cardíaca grave. Objetivos: Estudar a evolução tardia de crianças e adultos jovens com BAVCi e estimulação crônica do ventrículo direito (VD), visando determinar: a prevalência de sinais clínicos e laboratoriais de insuficiência cardíaca e de remodelamento ventricular; a capacidade funcional; a qualidade de vida e fatores preditores de alterações clínicas, funcionais ou ecocardiográficas. Métodos: Estudo transversal realizado em coorte de portadores de BAVCi e MP implantado antes de 21 anos de idade com estimulação no VD há mais de um ano. Todos os indivíduos foram submetidos a avaliação clínica e laboratorial, da capacidade funcional, da qualidade de vida e a ecocardiograma. Mães e sujeitos da pesquisa foram investigados para doenças reumatológicas. Os dados foram armazenados no sistema REDCap (Research Electronic Data Capture) e analisados pelos programas SAS (Statistical Analysis System), SPSS (Statistical Package for the Social Sciences) e R Studio. A análise dos dados incluiu: análise univariada para pesquisa de associações entre variáveis preditoras e desfechos, coeficiente de correlação de Pearson e modelo de regressão linear multivariado. Resultados: De março/2010 a dezembro/2013, foram avaliados 63 indivíduos, 68% do sexo feminino, com idade de 1 a 40 anos, com MP por 13,4 ± 6,5 anos e estimulação do VD por 10,0 ± 5,4 anos. O modo de estimulação era atrioventricular em 55,6%, o percentual de estimulação de VD de 97,9 ± 4,2% e a duração do complexo QRS estimulado de 152,4 ± 20,1 ms. A maioria (88,9%) era assintomática e não utilizava medicamentos de ação cardiovascular. Maior tempo de MP (P= 0,013), maior tempo de estimulação do VD (P= 0,005), maior idade na inclusão no estudo (P= 0,032) ou menor fração de ejeção do ventrículo (FEVE) (P= 0,013) associaram-se com a presença de classe funcional II (NYHA) e/ou uso medicamentos. Os valores do peptídeo natriurético tipo B foram normais em todos os exames laboratoriais, mas houve alteração da proteína C reativa ultrassensível, fator de necrose tumoral alfa e interleucina-6 em 66%, 34% e 13% exames, respectivamente. A distância média percorrida no teste de caminha de seis minutos foi de 546,9 ± 76,2 metros (91,0 ± 12,5% do valor predito). Os escores médios da qualidade de vida foram 78,1 ± 17,7 para o \"Sumário Físico\" e 76,6 ± 17,1 para o \"Sumário Mental\" do questionário Short Form 36 (SF-36) e de 77,4 ± 18,5, para o \"Sumário Físico\" e de 77,7 ± 21,6 para o \"Sumário Psicossocial\", do Child Health Questionnaire - Parent Form 50 (CHQ-PF50). Diminuição da FEVE foi detectada em 39,7% e aumento do diâmetro diastólico do ventrículo esquerdo (DDVE) em 22,2% dos indivíduos. A idade mais avançada no primeiro implante de MP se correlacionou negativamente com menor FEVE (r= -0,302; P= 0,016); a duração do complexo QRS estimulado (r= 0,447; P= 0,002) e maior tempo sob estimulação do VD (r= 0,416; P= 0,007) se correlacionaram positivamente ao aumento do DDVE. Foi detectada dissincronia ventricular em 60,3% dos indivíduos. O retardo da ativação eletromecânica intraventricular esquerda foi de 86,5 ± 56,9 ms e interventricular, de 141,9 ± 88 ms. Contudo, não houve correlação com os fatores estudados. Autoanticorpos anti-Ro/SSA foram detectados em 18 (32,1%) mães, com associação entre idade no momento do implante do MP (P= 0,032) e uso de MP ventricular no momento do estudo (P= 0,022). A regressão linear multivariada confirmou a correlação entre a idade no momento do implante do MP com a FEVE (P= 0,016), da duração do complexo QRS estimulado (P= 0,004) e do tempo sob estimulação do VD (P= 0,014) com o DDVE. Conclusões: A prevalência de manifestações clínicas e laboratoriais de insuficiência cardíaca foi baixa; por outro lado, a de remodelamento ventricular esquerdo foi elevada. A capacidade funcional foi satisfatória, assim como a qualidade de vida, nos aspectos físicos e emocionais. Idade mais avançada no primeiro implante de MP, maior tempo sob estimulação cardíaca e complexo QRS estimulado mais alargado foram fatores independentes de remodelamento ventricular e/ou de manifestação de insuficiência cardíaca / Introduction: Isolated congenital atrioventricular block (iCAVB) is a rare condition with multiple clinical presentations. Permanent cardiac pacing is the most effective therapy for this population resulting in satisfactory long-term outcomes. However, approximately 10% of patients may have ventricular remodeling and severe heart failure. Objectives: To study the long-term effects of chronic right ventricular (RV) pacing in children and young adults with iCAVB in order to determine: prevalence of clinical and laboratory signs of heart failure and ventricular remodeling, functional capacity, quality of life and predictors of clinical, functional or echocardiographic abnormalities. Methods: Cross-sectional study of a cohort of iCAVB patients with <= 21 years old at initial pacemaker (PM) implantation and single or dual-chamber pacing in a unique RV site for a minimum of one year. All subjects underwent clinical and laboratory assessment, functional capacity, quality of life and echocardiogram. Mothers and research subjects were investigated for rheumatic diseases. Data were stored in REDCap (Research Electronic Data Capture) system and analyzed by SAS (Statistical Analysis System), SPSS (Statistical Package for the Social Sciences) and R Studio programs. Data analysis included: univariate analysis for associations between predictor variables and outcomes, Pearson correlation coefficient and linear regression multivariate model. Results: Between March/2010 and December/2013, we evaluated 63 subjects aged 1-40 years old, 68% female, under PM for 13.4 ± 6.5 years and under RV pacing for 10.0 ± 5.4 years. Pacing mode was atrioventricular in 55.6%, percentage of RV pacing was 97.9 ± 4.2% and paced QRS duration was 152.4 ± 20.1 ms. Overall, the majority (88.9%) were asymptomatic and did not use cardiovascular drugs. Longer time under PM (P= 0.013), or even under RV pacing (P= 0.005), higher age at study inclusion (P= 0.032) and lower left ventricular ejection fraction (LVEF) (P= 0.013) were associated with functional class II (NYHA) and / or drug use. B-natriuretic peptide values were normal in all tests. C reactive protein ultrasensitive, tumor necrosis factor alfa and interleukin-6 were increased in 66%, 34% and 13% tests, respectively. The mean walked distance in the sex minute walk test was 546.9 ± 76.2 meters (91.0 ± 12.5% of the predicted value). Mean scores of quality of life were 78.1 ± 17.7 for \"Physical Summary\" and 76.6 ± 17.1 for \"Mental Summary\" in the Short Form 36 (SF-36) and 77.4 ± 18.5 for \"Physical Summary\" and 77.7 ± 21.6 for \"Psychosocial Summary\", of Child Health Questionnaire - Parent Form 50 (CHQ-PF50). Decreased LVEF was detected in 39.7% and increased left ventricular end-diastolic diameter (LVDD) in 22.2% of subjects. Higher age at the first PM implant was negatively correlated with lower LVEF (r= -0.302; P= 0.016); paced QRS duration (r= 0.447; P= 0.002) and time under RV pacing (r= 0.416; P= 0.007) were positively correlated with LVDD. Ventricular dyssynchrony was detected in 60.3 % of individuals. Intra-left ventricular electromechanical delay was 86.5 ± 56.9 ms and interventricular was 141.9 ± 88 ms. However, ventricular dyssynchrony was not correlated with the studied variables. Autoantibodies anti-SSA/Ro were detected in 18 (32.1%) mothers. There was association between age at PM implant (P= 0.032) and use of ventricular PM at the time of the study (P= 0.022) and presence of anti-SSA/Ro. Multivariate linear regression showed significant correlation between age at PM implant with LVEF (P= 0.016); and paced QRS duration (P= 0.005) and time under RV pacing (P= 0.014) with LVDD. Conclusions: Clinical and laboratorial manifestations of heart failure presented low prevalence in this population. On the other hand, the prevalence of left ventricular remodeling was high. Functional capacity was adequate, as well as quality of life, in both physical and emotional aspects. Higher age at first PM implant, longer time under pacing and wider paced QRS duration were independent factors of ventricular remodeling and/or manifestation of heart failure

Introdução: O bloqueio atrioventricular congênito isolado (BAVCi) é raro e tem múltiplas apresentações clínicas. O implante de marca-passo cardíaco permanente (MP) é o tratamento de escolha, resultando em evolução clínica satisfatória para a maioria dos casos, porém, aproximadamente 10% deles apresentam remodelamento ventricular e insuficiência cardíaca grave. Objetivos: Estudar a evolução tardia de crianças e adultos jovens com BAVCi e estimulação crônica do ventrículo direito (VD), visando determinar: a prevalência de sinais clínicos e laboratoriais de insuficiência cardíaca e de remodelamento ventricular; a capacidade funcional; a qualidade de vida e fatores preditores de alterações clínicas, funcionais ou ecocardiográficas. Métodos: Estudo transversal realizado em coorte de portadores de BAVCi e MP implantado antes de 21 anos de idade com estimulação no VD há mais de um ano. Todos os indivíduos foram submetidos a avaliação clínica e laboratorial, da capacidade funcional, da qualidade de vida e a ecocardiograma. Mães e sujeitos da pesquisa foram investigados para doenças reumatológicas. Os dados foram armazenados no sistema REDCap (Research Electronic Data Capture) e analisados pelos programas SAS (Statistical Analysis System), SPSS (Statistical Package for the Social Sciences) e R Studio. A análise dos dados incluiu: análise univariada para pesquisa de associações entre variáveis preditoras e desfechos, coeficiente de correlação de Pearson e modelo de regressão linear multivariado. Resultados: De março/2010 a dezembro/2013, foram avaliados 63 indivíduos, 68% do sexo feminino, com idade de 1 a 40 anos, com MP por 13,4 ± 6,5 anos e estimulação do VD por 10,0 ± 5,4 anos. O modo de estimulação era atrioventricular em 55,6%, o percentual de estimulação de VD de 97,9 ± 4,2% e a duração do complexo QRS estimulado de 152,4 ± 20,1 ms. A maioria (88,9%) era assintomática e não utilizava medicamentos de ação cardiovascular. Maior tempo de MP (P= 0,013), maior tempo de estimulação do VD (P= 0,005), maior idade na inclusão no estudo (P= 0,032) ou menor fração de ejeção do ventrículo (FEVE) (P= 0,013) associaram-se com a presença de classe funcional II (NYHA) e/ou uso medicamentos. Os valores do peptídeo natriurético tipo B foram normais em todos os exames laboratoriais, mas houve alteração da proteína C reativa ultrassensível, fator de necrose tumoral alfa e interleucina-6 em 66%, 34% e 13% exames, respectivamente. A distância média percorrida no teste de caminha de seis minutos foi de 546,9 ± 76,2 metros (91,0 ± 12,5% do valor predito). Os escores médios da qualidade de vida foram 78,1 ± 17,7 para o \"Sumário Físico\" e 76,6 ± 17,1 para o \"Sumário Mental\" do questionário Short Form 36 (SF-36) e de 77,4 ± 18,5, para o \"Sumário Físico\" e de 77,7 ± 21,6 para o \"Sumário Psicossocial\", do Child Health Questionnaire - Parent Form 50 (CHQ-PF50). Diminuição da FEVE foi detectada em 39,7% e aumento do diâmetro diastólico do ventrículo esquerdo (DDVE) em 22,2% dos indivíduos. A idade mais avançada no primeiro implante de MP se correlacionou negativamente com menor FEVE (r= -0,302; P= 0,016); a duração do complexo QRS estimulado (r= 0,447; P= 0,002) e maior tempo sob estimulação do VD (r= 0,416; P= 0,007) se correlacionaram positivamente ao aumento do DDVE. Foi detectada dissincronia ventricular em 60,3% dos indivíduos. O retardo da ativação eletromecânica intraventricular esquerda foi de 86,5 ± 56,9 ms e interventricular, de 141,9 ± 88 ms. Contudo, não houve correlação com os fatores estudados. Autoanticorpos anti-Ro/SSA foram detectados em 18 (32,1%) mães, com associação entre idade no momento do implante do MP (P= 0,032) e uso de MP ventricular no momento do estudo (P= 0,022). A regressão linear multivariada confirmou a correlação entre a idade no momento do implante do MP com a FEVE (P= 0,016), da duração do complexo QRS estimulado (P= 0,004) e do tempo sob estimulação do VD (P= 0,014) com o DDVE. Conclusões: A prevalência de manifestações clínicas e laboratoriais de insuficiência cardíaca foi baixa; por outro lado, a de remodelamento ventricular esquerdo foi elevada. A capacidade funcional foi satisfatória, assim como a qualidade de vida, nos aspectos físicos e emocionais. Idade mais avançada no primeiro implante de MP, maior tempo sob estimulação cardíaca e complexo QRS estimulado mais alargado foram fatores independentes de remodelamento ventricular e/ou de manifestação de insuficiência cardíaca / Introduction: Isolated congenital atrioventricular block (iCAVB) is a rare condition with multiple clinical presentations. Permanent cardiac pacing is the most effective therapy for this population resulting in satisfactory long-term outcomes. However, approximately 10% of patients may have ventricular remodeling and severe heart failure. Objectives: To study the long-term effects of chronic right ventricular (RV) pacing in children and young adults with iCAVB in order to determine: prevalence of clinical and laboratory signs of heart failure and ventricular remodeling, functional capacity, quality of life and predictors of clinical, functional or echocardiographic abnormalities. Methods: Cross-sectional study of a cohort of iCAVB patients with <= 21 years old at initial pacemaker (PM) implantation and single or dual-chamber pacing in a unique RV site for a minimum of one year. All subjects underwent clinical and laboratory assessment, functional capacity, quality of life and echocardiogram. Mothers and research subjects were investigated for rheumatic diseases. Data were stored in REDCap (Research Electronic Data Capture) system and analyzed by SAS (Statistical Analysis System), SPSS (Statistical Package for the Social Sciences) and R Studio programs. Data analysis included: univariate analysis for associations between predictor variables and outcomes, Pearson correlation coefficient and linear regression multivariate model. Results: Between March/2010 and December/2013, we evaluated 63 subjects aged 1-40 years old, 68% female, under PM for 13.4 ± 6.5 years and under RV pacing for 10.0 ± 5.4 years. Pacing mode was atrioventricular in 55.6%, percentage of RV pacing was 97.9 ± 4.2% and paced QRS duration was 152.4 ± 20.1 ms. Overall, the majority (88.9%) were asymptomatic and did not use cardiovascular drugs. Longer time under PM (P= 0.013), or even under RV pacing (P= 0.005), higher age at study inclusion (P= 0.032) and lower left ventricular ejection fraction (LVEF) (P= 0.013) were associated with functional class II (NYHA) and / or drug use. B-natriuretic peptide values were normal in all tests. C reactive protein ultrasensitive, tumor necrosis factor alfa and interleukin-6 were increased in 66%, 34% and 13% tests, respectively. The mean walked distance in the sex minute walk test was 546.9 ± 76.2 meters (91.0 ± 12.5% of the predicted value). Mean scores of quality of life were 78.1 ± 17.7 for \"Physical Summary\" and 76.6 ± 17.1 for \"Mental Summary\" in the Short Form 36 (SF-36) and 77.4 ± 18.5 for \"Physical Summary\" and 77.7 ± 21.6 for \"Psychosocial Summary\", of Child Health Questionnaire - Parent Form 50 (CHQ-PF50). Decreased LVEF was detected in 39.7% and increased left ventricular end-diastolic diameter (LVDD) in 22.2% of subjects. Higher age at the first PM implant was negatively correlated with lower LVEF (r= -0.302; P= 0.016); paced QRS duration (r= 0.447; P= 0.002) and time under RV pacing (r= 0.416; P= 0.007) were positively correlated with LVDD. Ventricular dyssynchrony was detected in 60.3 % of individuals. Intra-left ventricular electromechanical delay was 86.5 ± 56.9 ms and interventricular was 141.9 ± 88 ms. However, ventricular dyssynchrony was not correlated with the studied variables. Autoantibodies anti-SSA/Ro were detected in 18 (32.1%) mothers. There was association between age at PM implant (P= 0.032) and use of ventricular PM at the time of the study (P= 0.022) and presence of anti-SSA/Ro. Multivariate linear regression showed significant correlation between age at PM implant with LVEF (P= 0.016); and paced QRS duration (P= 0.005) and time under RV pacing (P= 0.014) with LVDD. Conclusions: Clinical and laboratorial manifestations of heart failure presented low prevalence in this population. On the other hand, the prevalence of left ventricular remodeling was high. Functional capacity was adequate, as well as quality of life, in both physical and emotional aspects. Higher age at first PM implant, longer time under pacing and wider paced QRS duration were independent factors of ventricular remodeling and/or manifestation of heart failure