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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Noninvasive Estimation of Pulmonary Artery Pressure Using Heart Sound Analysis

Dennis, Aaron W. 07 December 2009 (has links) (PDF)
Right-heart catheterization is the most accurate method for estimating pulmonary artery pressure (PAP). Because it is an invasive procedure it is expensive, exposes patients to the risk of infection, and is not suited for long-term monitoring situations. Medical researchers have shown that PAP influences the characteristics of heart sounds. This suggests that heart sound analysis is a potential noninvasive solution to the PAP estimation problem. This thesis describes the development of a prototype system, called PAPEr, which estimates PAP noninvasively using heart sound analysis. PAPEr uses patient data with machine learning algorithms to build models of how PAP affects heart sounds. Data from 20 patients was used to build the models and data from another 31 patients was used as a validation set. PAPEr diagnosed these 31 patients for pulmonary hypertension with an accuracy of 77 percent.
2

Determinação dos valores da pressão da artéria pulmonar, da oximetria, da hemogasometria e dos teores plasmáticos de lactato em bezerros nos primeiros 30 dias de vida / Measurement of the pulmonary artery pressure, pulse oximetry, blood gas analysis and the levels of plasma lactate in calves during the first 30 days of life

Yasuoka, Melina Marie 27 August 2012 (has links)
A presente pesquisa avaliou a determinação dos valores da pressão da artéria pulmonar, da oximetria, da hemogasometria e dos teores plasmáticos de lactato em bezerros neonatos, com a finalidade de contribuir nos estudos de clonagem e no desenvolvimento de neonatologia veterinária. A monitorização logo após o parto e o nascimento se tornou necessária para a manutenção da vida destes animais, aprimorando-se os protocolos e procedimento tomados, a avaliação clínica do sistema cardiovascular e respiratório neste momento de transição e a partir disto, o objetivo deste trabalho foi padronizar a metodologia utilizada para avaliações hemodinâmica da pressão da artéria pulmonar por meio da utilização do cateter de Swan-Ganz em bezerros, padronizar a técnica de oximetria e correlacionar os resultados obtidos para saturação de oxigênio com aqueles encontrados na hemogasometria de sangue arterial, e estabelecer valores de referência e avaliar a influência dos primeiros 30 dias de vida na mensuração da pressão da artéria pulmonar, da oximetria, da hemogasometria e dos teores plasmáticos de lactato obtidos em bezerros sadios. Foram utilizados 10 bezerros hígidos do estado de São Paulo, acompanhados do nascimento aos 30 dias de vida, onde pudemos observar o fechamento do forame ovale e ducto arterioso na 1º semana de vida, utilizando o sangue misto, o sangue venoso também foi um ótimo avaliador de distúrbios acidobásico, no entanto não avalia a função respiratória; para isso bastou utilizar a oximetria de pulso como um método não invasivo, que nos fornece dados que a gasometria arterial iria fornecer com a saturação de oxigênio. E a mensuração do lactato sérico serve como um marcador biológico para prognóstico de diversas enfermidades, onde seu aumento no sangue demonstra uma má perfusão tecidual (hipóxia) / This study investigated the measurement of the pulmonary artery pressure, pulse oximetry, the blood gas, plasma lactate and glucose levels in newborn calves, in order to contribute in cloning studies and the development of neonatal veterinary medicine. Monitoring soon after birth or help the calving became necessary for the maintenance of life of these animals, improving the protocols and procedures taken, the clinical assessment of cardiovascular and respiratory systems in this time of life transition, the objective of this study was to standardize the methodology used for hemodynamic assessment of pulmonary artery pressure using a Swan-Ganz catheter in calves, standardize the technique of pulse oximetry and correlate the results obtained for oxygen saturation found in blood gas analysis of arterial blood, and set reference values and to evaluate the influence of the first 30 days of life in the measurement of pulmonary artery pressure, pulse oximetry, blood gas and the plasma lactate levels obtained in healthy calves. We used 10 calves healthy from Sao Paulo state, followed from birth to 30 days of life, where we could see the closure of the foramen ovale and ductus arteriosus in the 1st week of life, using the mixed blood, venous blood was also a great evaluator acid-base disturbance, but does not assess respiratory function. The pulse oximetry was good enough to evaluate the oxygen saturation like a noninvasive method. And the measurement of serum lactate serves as a biomarker for prognosis of various diseases, when increase in blood shows poor tissue perfusion (hypoxia)
3

Determinação dos valores da pressão da artéria pulmonar, da oximetria, da hemogasometria e dos teores plasmáticos de lactato em bezerros nos primeiros 30 dias de vida / Measurement of the pulmonary artery pressure, pulse oximetry, blood gas analysis and the levels of plasma lactate in calves during the first 30 days of life

Melina Marie Yasuoka 27 August 2012 (has links)
A presente pesquisa avaliou a determinação dos valores da pressão da artéria pulmonar, da oximetria, da hemogasometria e dos teores plasmáticos de lactato em bezerros neonatos, com a finalidade de contribuir nos estudos de clonagem e no desenvolvimento de neonatologia veterinária. A monitorização logo após o parto e o nascimento se tornou necessária para a manutenção da vida destes animais, aprimorando-se os protocolos e procedimento tomados, a avaliação clínica do sistema cardiovascular e respiratório neste momento de transição e a partir disto, o objetivo deste trabalho foi padronizar a metodologia utilizada para avaliações hemodinâmica da pressão da artéria pulmonar por meio da utilização do cateter de Swan-Ganz em bezerros, padronizar a técnica de oximetria e correlacionar os resultados obtidos para saturação de oxigênio com aqueles encontrados na hemogasometria de sangue arterial, e estabelecer valores de referência e avaliar a influência dos primeiros 30 dias de vida na mensuração da pressão da artéria pulmonar, da oximetria, da hemogasometria e dos teores plasmáticos de lactato obtidos em bezerros sadios. Foram utilizados 10 bezerros hígidos do estado de São Paulo, acompanhados do nascimento aos 30 dias de vida, onde pudemos observar o fechamento do forame ovale e ducto arterioso na 1º semana de vida, utilizando o sangue misto, o sangue venoso também foi um ótimo avaliador de distúrbios acidobásico, no entanto não avalia a função respiratória; para isso bastou utilizar a oximetria de pulso como um método não invasivo, que nos fornece dados que a gasometria arterial iria fornecer com a saturação de oxigênio. E a mensuração do lactato sérico serve como um marcador biológico para prognóstico de diversas enfermidades, onde seu aumento no sangue demonstra uma má perfusão tecidual (hipóxia) / This study investigated the measurement of the pulmonary artery pressure, pulse oximetry, the blood gas, plasma lactate and glucose levels in newborn calves, in order to contribute in cloning studies and the development of neonatal veterinary medicine. Monitoring soon after birth or help the calving became necessary for the maintenance of life of these animals, improving the protocols and procedures taken, the clinical assessment of cardiovascular and respiratory systems in this time of life transition, the objective of this study was to standardize the methodology used for hemodynamic assessment of pulmonary artery pressure using a Swan-Ganz catheter in calves, standardize the technique of pulse oximetry and correlate the results obtained for oxygen saturation found in blood gas analysis of arterial blood, and set reference values and to evaluate the influence of the first 30 days of life in the measurement of pulmonary artery pressure, pulse oximetry, blood gas and the plasma lactate levels obtained in healthy calves. We used 10 calves healthy from Sao Paulo state, followed from birth to 30 days of life, where we could see the closure of the foramen ovale and ductus arteriosus in the 1st week of life, using the mixed blood, venous blood was also a great evaluator acid-base disturbance, but does not assess respiratory function. The pulse oximetry was good enough to evaluate the oxygen saturation like a noninvasive method. And the measurement of serum lactate serves as a biomarker for prognosis of various diseases, when increase in blood shows poor tissue perfusion (hypoxia)
4

GRAD AV FÖRÄNDRING AV TRYCKGRADIENT HOS TRIKUSPIDALISINSUFFICIENS EFTER LÄTTARE FYSISK ANSTRÄNGNING

Fornell, Ellinor January 2018 (has links)
Klaffvitier är några av de vanligaste hjärtsjukdomarna och studier visar att fysisk aktivitet är en viktig del av den kliniska diagnostiken speciellt för individer med symtomfri problematik. Fysisk aktivitet leder hos en del individer till typiska symtom för klaffvitium och ger således möjlighet till förbättrad gradering av klaffvitier jämfört med i vila. Syftet med studien är att ekokardiografiskt studera eventuell förändring av trikuspidalisklaffunktion i vila och efter lättare fysisk ansträngning, samt undersöka hypotesen om trikuspidalisinsufficiens samt tryckgradienten över trikuspidalisklaffen förändras i samband med denna typ av diagnostik. Sexton deltagare inkluderas vid anamnes på andfåddhet eller ansträngningsutlösta hjärtbesvär samt även fynd av trikuspidalisinsufficiens i samband med ordinarie undersökningstillfälle. Även de med känd trikuspidalis-insufficiens sedan tidigare inkluderades. Efter ordinarie ekokardiografisk undersökning som individerna var remitterade till fick inkluderade deltagare utföra ett cykeltest på ergometercykel under sex minuter med en lättare belastning. Ultraljudsbilder på hjärtat samlades in direkt efter avslutad ansträngning. Två variabler, tryckgradient före respektive efter ansträngning över trikuspidalisklaffen, analyserades enligt dess differens och därefter analyserades differenserna i förhållande till nollhypotesen. Medianvärden av variablerna jämfördes i Wilcoxons teckenrangtest och med Spearmans rangkorrelation studerades förhållandet mellan stigande hjärtfrekvens samt tryckgradient vid fysisk ansträngning. Studien visade att tryckgradienten hos trikuspidalis-insufficiensen förändrades vid utförande av lättare fysisk ansträngning hos individer med ansträngningsutlösta hjärtbesvär samt att denna form av undersökning i anslutning till ordinarie undersökningstillfälle kan vara av värde bland individer med anamnes på ansträngningsutlösta hjärtbesvär. / Valvular heart disease are one of the most common heart diseases and previous studies have shown that exercise is an important part of the clinical diagnostics, especially in asymphtomatic individuals. In some cases, exercise lead to typical symptoms of valvular heart disease and improved grading compared to rest. The aim of the present study was to analyze tricuspid valvular function in rest compared to exercise and examine whether or not tricuspid regurgitation and pressure gradient over the tricuspid valve will alter after exercise. Sixteen participants was included with anamnesis of dyspnea or cardiac symptoms related to exercise as well as findings of tricuspid regurgitation during the echocardio-graphic examination. Individuals with known tricuspid regurgitation were also included. After the transthoracic echocardiographic examination, included individuals performed a bicycle test for six minutes with light workload. Additional ultrasound images of the heart was collected immediately after finished bicycle test. Two variables, pressure gradient over the tricuspid valve before and after right exercise, were analyzed according to its difference and then the differences were analyzed relative to the zero hypothesis. Median values of the variables were compared in Wilcoxon's signed-rank test and Spearman's rank correlation analyzed the relationship between increasing heart rate and pressure gradient under the influence of exercise. This study has shown that the pressure gradient of the tricuspid regurgitation changes in the performance of light exercise in individuals with history of dyspnea or cardiac symptoms related to exercise. It also showed the value of an exercise test in adherence to the echocardiographic examination in this group of individuals.
5

Studies on bone marrow-derived stem cells in patients with acute myocardial infarction

Miettinen, J. (Johanna) 16 March 2011 (has links)
Abstract Intracoronary administration of autologous bone marrow derived stem cells (BMC) has been postulated to repair the myocardial damage in patients who have suffered acute ST-elevation myocardial infarction (STEMI). The aim of this study was to find determinants for the left ventricular functional recovery after BMC treatment of STEMI and to study the effect of BMC treatment on different biochemical and clinical parameters associated with the outcome of STEMI patients. In this study, STEMI patients treated with thrombolysis were randomly assigned to receive either intracoronary BMC (n=39) or placebo (n=39) into the infarct related artery at the time of percutaneous coronary intervention. The efficacy of the BMC treatment was assessed by measurement of the change of left ventricular ejection fraction (LVEF) from baseline to six months after STEMI. Two-dimensional echocardiography was used to assess PA pressure, LV systolic and diastolic function. Blood samples were drawn for biochemical determinations at several time points and BMCs were cultured in the laboratory for in vitro analyses. In the BMC group, the most powerful determinant of the change of LVEF was the baseline LVEF. Patients with baseline LVEF at or below the median (≤62.5%) experienced a more marked improvement of LVEF than those above the median. Elevated levels of N-terminal probrain natriuretic peptide (NT-proBNP) and N-terminal proatrial natriuretic peptide (NT-proANP) were also associated with an improvement of LVEF in the BMC group. However, no difference was observed between the BMC group and the placebo group in the changes of the levels of NT-proANP, NT-proBNP or any of the inflammatory markers measured. The BMC group showed a trend toward a reduction of peak PA pressure, while the placebo group had a significant increase of peak PA pressure at 6 months. In addition, there was a greater improvement in the LV diastolic function, assessed in quartiles, in the BMC group. The in vitro studies of BMCs revealed that exposure to tumor necrosis factor alpha (TNF-α) significantly enhanced the proliferation of BMCs and resulted in activation of immunosuppression by altering the expression of several immunosuppressive proteins. In conclusion, low baseline LVEF as well as high levels of natriuretic peptides NT-proANP and NT-proBNP, which reflect the severity of the hemodynamic and neurohumoral reactions evoked by the myocardial damage, have a considerable association to a better response to stem cell therapy after an acute STEMI. BMC therapy also prevents the increase of PA pressure and improves the cardiac diastolic function. Based on in vitro studies, the inflammatory cytokine TNF-α seems to evoke an enhanced proliferation of the bone marrow-derived mesenchymal stem cells and activation of several immunosuppressive defence mechanisms. / Tiivistelmä Sydäninfarktipotilaiden sepelvaltimoon pallolaajennuksen yhteydessä injektoitujen kantasolujen tiedetään parantavan hieman sydämen pumppauskykyä, mutta taustalla olevaa mekanismia ei tunneta. Kantasoluhoidon onnistumiseen vaikuttavia tekijöitä on tutkittu vasta vähän, eikä myöskään sitä tiedetä, miksi kaikki potilaat eivät hyödy kantasoluhoidosta. Tämän tutkimuksen tavoitteena oli selvittää infarktialueelle annetun kantasoluhoidon vaikutuksia äkillisen ST-nousuinfarktin (STEMI) sairastaneissa potilaissa, ja etsiä hoidon onnistumiseen vaikuttavia tekijöitä. Tutkimuksessa käytettiin potilasaineistoa, johon otettiin 78 äkilliseen sydäninfarktiin sairastunutta potilasta, jotka hoidettiin liuotushoidolla ja sen jälkeen pallolaajennuksella. Puolet potilaista satunnaistettiin saamaan lumeliuosta ja puolet omaa luuydinsolukkoaan (BMC), joka ruiskutettiin pallolaajennuksen yhteydessä sepelvaltimon kautta infarktialueelle. Hoidon vaikusta tutkittiin mittaamalla angiografian avulla vasemman kammion ejektiofraktion (LVEF) muutosta lähtötilanteen ja kuuden kuukauden seurannan välillä. Lisäksi sydämen ultraäänitutkimuksella määritettiin keuhkovaltimopainetta ja vasemman kammion systolista ja diastolista toimintaa. Potilaista otettiin lisäksi verinäytteitä, joista määritettiin erilaisia tulehdusmerkkiaineita ja natriureettisia peptidejä. Lisäksi potilaista kerättyjä luuydinkantasoluja viljeltiin laboratoriossa in vitro-analyyseja varten. Tutkimuksessa todettiin, että LVEF ennen kantasoluhoitoa oli voimakkain ennustetekijä suotuisalle LVEF:n muutokselle kantasoluhoidon jälkeen. Potilaat, joilla LVEF oli ennen kantasoluhoitoa alle mediaaniarvon (≤62.5%), hyötyivät kantasoluhoidosta enemmän kuin potilaat, joilla LVEF oli yli mediaanin. Myös natriureettisten peptidien NT-proBNP:n ja NT-proANP:n korkea taso infarktin jälkeen oli yhteydessä suurempaan LVEF:n paranemiseen BMC-potilailla. Natriureettisten peptidien ja tulehdusmerkkiaineiden pitoisuuksien muutoksissa kantasoluhoidon jälkeen ei kuitenkaan todettu eroa BMC- ja kontrolliryhmän välillä. Sydämen diastolisen toiminnan havaittiin paranevan enemmän BMC-ryhmässä kuin kontrolliryhmässä. Lisäksi BMC-ryhmässä havaittiin lievää laskua keuhkovaltimopaineessa, kun taas kontrolliryhmässä se nousi merkittävästi. In vitro-tutkimukset luuytimestä erilaistetuilla mesenkymaalisilla kantasoluilla puolestaan osoittivat, että tuumorinekroositekijä alfa (TNF-α)-altistus lisäsi solujakautumista ja monien immunosupressiivisten proteiinien tuottoa soluissa. Matala LVEF sekä natriureettisten peptidien NT-proBNP:n ja NT-proANP:n korkea taso sydäninfarktin jälkeen kuvaavat infarktivaurion aiheuttamien hemodynaamisten ja neurohumoraalisten reaktioiden vakavuutta, ja tässä tutkimuksessa niiden osoitettiin olevan vahvasti yhteydessä äkillisen ST-nousuinfarktin jälkeen annetun kantasoluhoidon hyötyyn. Kantasoluhoito saattaa myös suojata infarktipotilaita haitalliselta keuhkovaltimopaineen nousulta ja parantaa sydämen diastolista toimintaa. Tulehdusvälittäjäaine TNF-α näytti in vitro-kokeiden perusteella lisäävän luuytimen mesenkymaalisten kantasolujen jakautumista ja aktivoivan niissä monia immunosuppressiivisia puolustusmekanismeja tulehdusta vastaan.

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