Robust temporal alignment of multimodal cardiac sequences

Given the dynamic nature of cardiac function, correct temporal alignment of pre-operative models and intraoperative images is crucial for augmented reality in cardiac image-guided interventions. As such, the current study focuses on the development of an image-based strategy for temporal alignment of multimodal cardiac imaging sequences, such as cine Magnetic Resonance Imaging (MRI) or 3D Ultrasound (US). First, we derive a robust, modality-independent signal from the image sequences, estimated by computing the normalized crosscorrelation between each frame in the temporal sequence and the end-diastolic frame. This signal is a resembler for the left-ventricle (LV) volume curve over time, whose variation indicates di erent temporal landmarks of the cardiac cycle. We then perform the temporal alignment of these surrogate signals derived from MRI and US sequences of the same patient through Dynamic Time Warping (DTW), allowing to synchronize both sequences. The proposed framework was evaluated in 98 patients, which have undergone both 3D+t MRI and US scans. The end-systolic frame could be accurately estimated as the minimum of the image-derived surrogate signal, presenting a relative error of 1:6 1:9% and 4:0 4:2% for the MRI and US sequences, respectively, thus supporting its association with key temporal instants of the cardiac cycle. The use of DTW reduces the desynchronization of the cardiac events in MRI and US sequences, allowing to temporally align multimodal cardiac imaging sequences. Overall, a generic, fast and accurate method for temporal synchronization of MRI and US sequences of the same patient was introduced. This approach could be straightforwardly used for the correct temporal alignment of pre-operative MRI information and intra-operative US images.

Improving The Robustness Of Interventional 4D Ultrasound Segmentation Through The Use Of Personalized Shape Priors

While fluoroscopy is still the most widely used imaging modality to guide cardiac interventions, the fusion of pre-operative Magnetic Resonance Imaging (MRI) with real-time intra-operative ultrasound (US) is rapidly gaining clinical acceptance as a viable, radiation-free alternative. In order to improve the detection of the left ventricular (LV) surface in 4D ultrasound, we propose to take advantage of the pre-operative MRI scans to extract a realistic geometrical model representing the patients cardiac anatomy. This could serve as prior information in the interventional setting, allowing to increase the accuracy of the anatomy extraction step in US data. We have made use of a real-time 3D segmentation framework used in the recent past to solve the LV segmentation problem in MR and US data independently and we take advantage of this common link to introduce the prior information as a soft penalty term in the ultrasound segmentation algorithm. We tested the proposed algorithm in a clinical dataset of 38 patients undergoing both MR and US scans. The introduction of the personalized shape prior improves the accuracy and robustness of the LV segmentation, as supported by the error reduction when compared to core lab manual segmentation of the same US sequences.

Health related quality of life in patients with refractory chronic heart failure undergoing cardiac resynchronization: type of therapeutic response

The benefits of cardiac resynchronization therapy (CRT) in the health-related quality of life (HRQL) are largely demonstrated in selected patients with severe congestive heart failure (CHF). However, the differences between responders and non-responders, with regard to the effect of CRT in the various dimensions that constitute HRQL are still a matter of discussion. Objective: To evaluate the impact of CRT on the HRQL of patients with CHF refractory to optimal pharmacological therapy, within 6 months after CRT. Methods: 43 patients, submitted to successful implantation of CRT, were evaluated in hospital just before intervention and in the outpatient clinic within 6 months after CRT. HRQL was analyzed based on the Kansas City Cardiomyopathy Questionnaire (KCCQ). Patients were classified as super-responders (ejection fraction of left ventricle - LVEF - ≥45% post-CRT), n=15, responders (sustained improvement in functional class and LVEF increased by 15%), n=19, and non-responders (no clinical or LVEF improvement), n=9. Results: In the group of super-responders, CRT was associated with an improvement in HRQL for the various fields and sums assessed (ρ<0.05); in responders, CRT has been associated with an improvement of HRQL in the various fields and sums, except in the self-efficacy dimension (ρ<0.05); in non-responders, CRT was not associated with improvement of HRQL. Conclusion: In a population with severe CHF undergoing CRT, the patients with clinical and echocardiographic positive response, obtained a favorable impact in all dimensions of HRQL, while the group without response to CRT showed no improvement. These data reinforces the importance of HRQL as a multidimensional tool for assessment of benefits in clinical practice.

Variáveis psicológicas e percepção do estado de saúde em indivíduos submetidos a ressincronização cardíaca

A insuficiência cardíaca afecta cerca de 261 mil pessoas em Portugal constituindo um problema de saúde pública. Pretendemos avaliar aspectos associados à recuperação do estado de saúde nesta síndrome, em particular a esperança, o afecto e a felicidade. Recorremos a um estudo longitudinal com 128 indivíduos sintomáticos com má fracção de ejecção do ventrículo esquerdo. Utilizámos um questionário para caracterizar os aspectos sóciodemográficos, clínicos e funcionais, o Kansas City Cardiomiopathy Questionnaire (KCCQ) para avaliar a qualidade de vida, a Subjective Hapiness Scale (SHS) para a felicidade, a HOPE Scale (HOPE) para a esperança e a Positive And Negative Afect Schedule (PANAS) para o afecto. Os questionários de caracterização sócio-demográfica, clínica e funcional, KCCQ e o SHS foram aplicados em três momentos: no internamento, prévio à instituição de terapêutica médica na sua totalidade e ao terceiro e sexto mês após a intervenção médica, na consulta externa. A maioria dos participantes eram homens em classe III da classificação da New York Heart Association com etiologia isquémica. No internamento e antes da terapêutica médica, observámos que a esperança, a felicidade e o afecto se relacionaram com a qualidade de vida, a felicidade e o afecto positivo com a esperança. No período avaliado foram submetidos a: terapia de ressincronização cardíaca (n=52), cardioversor-desfibrilhador implantável (n=44), cirurgia valvular com revascularização do miocárdio (n=14), optimização terapêutica farmacológica (n=10), transplante cardíaco (n=8). Foram significativos os resultados da qualidade de vida, da classificação da New York Heart Association, do exercício físico, da fracção de ejecção do ventrículo esquerdo e das arritmias cardíacas (estrasístoles e taquicardias ventriculares). A felicidade foi preditora da qualidade de vida e da funcionalidade. O afecto negativo foi preditor da satisfação com a insuficiência cardíaca. Concluímos da importância das variáveis positivas a par dos procedimentos médicos no tratamento das pessoas com insuficiência cardíaca. ABSTRACT - Heart failure affects about 261 000 people in Portugal constituting a public health problem. We intend to evaluate aspects of the health recovery in this syndrome, in particular hope, affection and happiness. We used a longitudinal study with 128 symptomatic patients with poor ejection fraction of left ventricle. We used a questionnaire to characterize the socio-demographic, clinical and functional aspects, the Kansas City Cardiomiopathy Questionnaire (KCCQ) to assess the quality of life, the Subjective Happiness Scale (SHS) for happiness, the HOPE Scale (HOPE) for hope and the Positive And Negative Affect Schedule (PANAS) for affection. The questionnaires of sociodemographic, clinical and functional KCCQ and SHS were applied on three occasions: on admission, prior to the execution of medical therapy in its totality and in the third and sixth months after medical intervention in the outpatient. Most of the participants were men in Class III New York Heart Association classification with ischemic etiology. At admission and before medical therapy, we observed that the hope, happiness and affection were related to the quality of life, happiness and positive affect with hope. Over the studied period were submitted to: cardiac resynchronization therapy (n=52), implantable cardioverter-defibrillator (n=44), valvular surgery with coronary artery bypass graft surgery (n=14), optimizing drug therapy (n=10), heart transplant (n=8). The significant results were the quality of life, the New York Heart Association classification, the exercise, the ejection fraction and left ventricular cardiac arrhythmias (ventricular tachycardia and estrasistoles). Happiness was a predictor of quality of life and functionality. The negative affect was a predictor of satisfaction with heart failure. We concluded that the positive variables and the medical procedures were important in treating people with heart failure.

Deformação miocárdica analisada por Speckle Tracking, em doentes hipertensos com fracção de ejecção preservada

Mestrado em Tecnologia de Diagnóstico e Intervenção Cardiovascular - Área de especialização: Ultrassonografia Cardiovascular.

Deformação miocárdica analisada por 2D strain em indivíduos com lúpus eritematoso sistémico

Mestrado em Tecnologia de Diagnóstico e Intervenção Cardiovascular. Área de especialização: Ultrassonografia Cardiovascular.

Perfil ecocardiográfico do doente com estenose aórtica degenerativa

Mestrado em Tecnologia de Diagnóstico e Intervenção Cardiovascular - Área de especialização: Ultrassonografia Cardiovascular.

Avaliação da função diastólica no ventrículo esquerdo em mulheres hipertensas com excesso de peso ou obesidade

Mestrado em Tecnologia de Diagnóstico e Intervenção Cardiovascular - Ramo de especialização: Ultrassonografia Cardiovascular

Avaliação da função ventricular esquerda por ecocardiografia bidimensional com VVI em indivíduos hipertensos voluntários

Mestrado em Tecnologia de Diagnóstico e Intervenção Cardiovascular - Ramo de especialização: Ultrassonografia Cardiovascular

Influência da experiência profissional e da função visual do operador no processamento semiautomático da cintigrafia de perfusão do miocárdio: variabilidade intra e interoperador na determinação dos parâmetros quantitativos

Introdução – A cintigrafia de perfusão do miocárdio (CPM) desempenha um importante papel no diagnóstico, avaliação e seguimento de pacientes com doença arterial coronária, sendo o seu processamento realizado maioritariamente de forma semiautomática. Uma vez que o desempenho dos técnicos de medicina nuclear (TMN) pode ser afetado por fatores individuais e ambientais, diferentes profissionais que processem os mesmos dados poderão obter diferentes estimativas dos parâmetros quantitativos (PQ). Objetivo – Avaliar a influência da experiência profissional e da função visual no processamento semiautomático da CPM. Analisar a variabilidade intra e interoperador na determinação dos PQ funcionais e de perfusão. Metodologia – Selecionou-se uma amostra de 20 TMN divididos em dois grupos, de acordo com a sua experiência no software Quantitative Gated SPECTTM: Grupo A (GA) – TMN ≥600h de experiência e Grupo B (GB) – TMN sem experiência. Submeteram-se os TMN a uma avaliação ortóptica e ao processamento de 21 CPM, cinco vezes, não consecutivas. Considerou-se uma visão alterada quando pelo menos um parâmetro da função visual se encontrava anormal. Para avaliar a repetibilidade e a reprodutibilidade recorreu-se à determinação dos coeficientes de variação, %. Na comparação dos PQ entre operadores, e para a análise do desempenho entre o GA e GB, aplicou-se o Teste de Friedman e de Wilcoxon, respetivamente, considerando o processamento das mesmas CPM. Para a comparação de TMN com visão normal e alterada na determinação dos PQ utilizou-se o Teste Mann-Whitney e para avaliar a influência da visão para cada PQ recorreu-se ao coeficiente de associação ETA. Diferenças estatisticamente significativas foram assumidas ao nível de significância de 5%. Resultados e Discussão – Verificou-se uma reduzida variabilidade intra (<6,59%) e inter (<5,07%) operador. O GB demonstrou ser o mais discrepante na determinação dos PQ, sendo a parede septal (PS) o único PQ que apresentou diferenças estatisticamente significativas (zw=-2,051, p=0,040), em detrimento do GA. No que se refere à influência da função visual foram detetadas diferenças estatisticamente significativas apenas na fração de ejeção do ventrículo esquerdo (FEVE) (U=11,5, p=0,012) entre TMN com visão normal e alterada, contribuindo a visão em 33,99% para a sua variação. Denotaram-se mais diferenças nos PQ obtidos em TMN que apresentam uma maior incidência de sintomatologia ocular e uma visão binocular diminuída. A FEVE demonstrou ser o parâmetro mais consistente entre operadores (1,86%). Conclusão – A CPM apresenta-se como uma técnica repetível e reprodutível, independente do operador. Verificou-se influência da experiência profissional e da função visual no processamento semiautomático da CPM, nos PQ PS e FEVE, respetivamente.

Estudo da deformação miocárdica para detecção precoce de disfunção ventricular esquerda em doentes submetidos a quimioterapia com antraciclinas

Mestrado em Tecnologia de Diagnóstico e Intervenção Cardiovascular - Área de especialização: Ultrassonografia cardiovascular

HEART ANEURYSM IN CHAGAS' DISEASE

This prospective study on 41 autopsy collected human hearts concerns the "apical" lesion in Chagas' disease. Previous report did not show a correlation between lesion frequency and heart weight then discarding a vascular factor in its pathogenesis. The present paper involves other variables besides the heart weight to evaluate the relative coronary insufficiency. Distinct colored gel (green and red) injected through the capillary beds of both coronary arteries defined the extent of both vessels before separating the atria and removing the sub-epicardium fat. The Right Ventricle (RV) and Left Ventricle (LV) free walls furnished the RV/LV mass ratio. The myocardium mass colored green (right coronary artery - RC) and the whole Ventricular Weight (VW) determined the RC/VW mass ratio. The heart weight plus these mass ratios, graded and added, composed a score inversely proportional to the myocardium irrigation condition. It intended to be a more sensitive morphologic evaluation of the relative ischaemia to correlate to the apical lesion. This study showed a right deviation for the relative accumulated frequency of lesions plotted as a score function and a significant difference for higher scores in hearts with aneurysm. It suggests a ischaemic factor intervening in the apical lesion pathogenesis in Chagas' cardiopathy.

Enfarte Agudo do Miocárdio na Criança

A retrospective study was made of 6 children, with nonsurgical-related acute myocardial infarction (AMI), between January 1987 and December 1994. The ratio for gender was 1 and mean age at AMI was 49 days, 4 cases being associated with congenital heart disease (Fallot's tetralogy, truncus arteriosus and DiGeorge syndrome, one case each, and anomalous origin of left coronary artery, 2 cases). Kawasaki disease and coronary embolisation from thrombosis of the renal vein occurred in the other 2 cases respectively. All developed congestive cardiac failure and cardiomegaly. In the ECG pathologic q waves with more than 35 msec occurred in all, and QT prolongation occurred in 3. Five children (83%) all with AMI in the anterior and lateral wall of the left ventricle died, death being related with cardiac mechanical failure and not with arrhythmias.

Utilidade de Ecocardiografia da Sobrecarga Farmacológica com Dobutamina nas Cardiomiopatias Dilatadas não Isquémicas

INTRODUCTION: Low-dose dobutamine stress echocardiography is a common and useful technique to assess myocardial viability in patients with ischemic cardiomyopathy. OBJECTIVE: To evaluate the use of low-dose dobutamine stress echocardiography in determining the functional status of patients with idiopathic dilated cardiomyopathy (IDCM). METHODS: Prospective study of 28 patients with IDCM by transthoracic echocardiography (2D), low-dose dobutamine stress echocardiography, cardiopulmonary exercise testing (CPET) and measurement of pro-BNP. RESULTS: The mean age of the population was 50.3 +/- 11.5 years, 9 female and 19 male. Mean ejection fraction was 32.1 +/- 9.8%. All were in sinus rhythm. The following parameters were analyzed in 2D echocardiography and after dobutamine: dimensions of left atrium (LA) and of left ventricle in diastole and systole, shortening fraction (%), left ventricular end-diastolic (EDV) and end-systolic volumes (ESV), ejection fraction (EF), and mitral inflow (E, A, E/A ratio and deceleration time). In CPET, we considered the following parameters: peak VO2 and % maximal peak VO2 attained. We compared echo results with CPET. There was a correlation between age and peak VO2 (r = -0.38 with p = 0.049). In 2D echo, there was a correlation between baseline EF and LA dimensions and peak VO2 (r = 0.45 / p = 0.004 and r = -0.49 / p = 0.014, respectively). After dobutamine echo, there was a correlation between some echo parameters and peak VO2: EF - r = 0.59 / p = 0.001, LA dimensions - r = 0.56 / p = 0.007, and ESV - r = -0.45 / p = 0.026. Percentage maximal peak VO2 attained correlated with LA dimensions measured in 2D echo and after dobutamine (r = -0.398 / p = 0.036 and r = -0.674 / p = 0.02 respectively) and EF after dobutamine (r = -0.389 / p = 0.04). The value of pro-BNP correlated with LA dimensions and baseline EF (r = 0.44 / p = 0.02 and r = -0.57 / p = 0.002, respectively), and the correlation was maintained after inotropic stimulation with dobutamine (r = 0.57 / p = 0.001 and r = -0.55 / p = 0.0039). CONCLUSION: Low-dose dobutamine stress echocardiography showed stronger correlations with cardiopulmonary exercise testing than the parameters evaluated by conventional echocardiography and could be used to determine the functional status of patients with dilated cardiomyopathy; patients with greater ejection fraction after inotropic stimulation had better cardiopulmonary tests.

Volumoso Pseudoaneurisma do Ventrículo Esquerdo após Cirurgia Cardíaca

A 75-year old female patient, with previous inferior acute myocardial infarction (AMI) in December 2000, was admitted in April 2001 with angina and heart failure. Transthoracic echocardiography (TTE) was suggestive of a postero-inferior pseudoaneurysm (PA) of the left ventricle (LV), with 61x49 mm. of size and mitral regurgitation. Cardiac catheterization was suspected of a PA of the LV and revealed a three vessels coronary artery disease. On 20th April she was submitted to cardiac surgery with resection of a large LV aneurysm (AN) and triple coronary artery bypass surgery. Afterwards, she was on NYHA class III and subsequent TTE and transesophagic echocardiography (TEE) were suggestive of a 90x60 mm LV posterior PA (confirmed by nuclear magnetic resonance) and severe mitral regurgitation, with good LV systolic function. She underwent a new cardiac surgery on 31st May 2002, with resuturing of the LV postero-inferior wall patch and removal of the PA. The patient is in good condition and on NYHA functional class I-II.