4 resultados para HEART FUNCTION
em Repositório Científico do Instituto Politécnico de Lisboa - Portugal
Resumo:
Mestrado em Tecnologia de Diagnóstico e Intervenção Cardiovascular. Área de especialização - Ultrassonografia Cardiovascular
Resumo:
Heart failure is the final stage of most of cardiac diseases. It is a complex syndrome in which the patients should have the following features: symptoms of heart failure, typically shortness of breath at rest or during exertion, and/or fatigue; signs of fluid retention such as pulmonary congestion or ankle swelling; and objective evidence of an abnormality of the structure or function of the heart at rest. This progressive syndrome as a high incidence and prevalence and poor prognosis: four-year mortality is around 50% with 40% of the patients admitted to hospital dying or readmitted within a year. With ageing, many patients will develop chronic heart failure, which, because of its symptoms, patient’s awareness of their risk of dying, and the effects of therapy, together with frequent hospitalizations, has considerable impact on patient’s health-related quality of life.
Resumo:
A crucial method for investigating patients with coronary artery disease (CAD) is the calculation of the left ventricular ejection fraction (LVEF). It is, consequently, imperative to precisely estimate the value of LVEF--a process that can be done with myocardial perfusion scintigraphy. Therefore, the present study aimed to establish and compare the estimation performance of the quantitative parameters of the reconstruction methods filtered backprojection (FBP) and ordered-subset expectation maximization (OSEM). Methods: A beating-heart phantom with known values of end-diastolic volume, end-systolic volume, and LVEF was used. Quantitative gated SPECT/quantitative perfusion SPECT software was used to obtain these quantitative parameters in a semiautomatic mode. The Butterworth filter was used in FBP, with the cutoff frequencies between 0.2 and 0.8 cycles per pixel combined with the orders of 5, 10, 15, and 20. Sixty-three reconstructions were performed using 2, 4, 6, 8, 10, 12, and 16 OSEM subsets, combined with several iterations: 2, 4, 6, 8, 10, 12, 16, 32, and 64. Results: With FBP, the values of end-diastolic, end-systolic, and the stroke volumes rise as the cutoff frequency increases, whereas the value of LVEF diminishes. This same pattern is verified with the OSEM reconstruction. However, with OSEM there is a more precise estimation of the quantitative parameters, especially with the combinations 2 iterations × 10 subsets and 2 iterations × 12 subsets. Conclusion: The OSEM reconstruction presents better estimations of the quantitative parameters than does FBP. This study recommends the use of 2 iterations with 10 or 12 subsets for OSEM and a cutoff frequency of 0.5 cycles per pixel with the orders 5, 10, or 15 for FBP as the best estimations for the left ventricular volumes and ejection fraction quantification in myocardial perfusion scintigraphy.
Resumo:
The scientific evidence supporting the management of the chronically ill in a positive psychological perspective in opposition to traditional pathological approach is scarce. This study examines issues associated with recovery of health status in heart failure, in particular hope, affection, and happiness. We use a longitudinal study of 128 symptomatic patients who after medical intervention reported improved quality of life and function at 3-month follow-up. We evaluated the contribution of happiness, hope and affection, individually and as a whole, in the quality of life and functionality of individuals with heart failure. Happiness (Subjective Happiness Scale), Hope (HOPE Scale), and affection (PANAS (positive and negative affect schedule)) were determined before medical intervention. Individually, we found that happiness is correlated with the quality of life and functionality, hope to self-efficacy dimension of the quality of life scale, positive affect to functionality and negative affect with symptoms dimension, quality of life dimension, and overall sum of the quality of life scale. Overall, we found that happiness has a unique contribution to the quality of life, except in self-efficacy dimension where hope takes this contribution and positive affect has a unique contribution to the functionality in this short-term follow-up. The results highlight the importance of positive variables to health outcomes for people with heart failure and should be considered in intervention programs for this syndrome.