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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

Correlation between COPD and pulmonary hypertension

Haghighi, Maryam January 2005 (has links)
Chronic obstructive pulmonary disease (COPD) is in up to 90 % of all cases caused by smoking. COPD often has negative effects on circulation, effects that first and foremost can be observed as respiratory insufficiency. Reduced function of the right ventricle of the heart is common in patients suffering from chronic obstructive pulmonary disease, especially if they also have hypoxemi; insufficient levels of oxygen in blood or tissue. The incidence of this cardiac complication reduces the survival time. It is possible in chronic obstructive pulmonary disease that the pressure in the pulmonary circulation gradually increases resulting in pulmonary hypertension followed by a slow adaptation of the right ventricle by hypertrophy of the myocardium. To investigate a correlation between COPD and pulmonary hypertension COPD patients were subjected to spirometry and ultrasound on heart. Of 14 examined patients 5 had developed pulmonary hypertension. A correlation between obstruction in the COPD- patients and an increase in left ventricular diameter was found. DLCO (diffusion capacity) of the lungs is directly connected to PA (pulmonary arterial pressure). The lower DLCO, the higher risk to develop pulmonary hypertension. However, we could not find a significant correlation between COPD and pulmonary hypertension in this study even if most patients had a decreased DLCO.
2

Lung function in relation to exercise capacity in health and disease

Farkhooy, Amir January 2017 (has links)
Background: Exercise capacity (EC) is widely recognized as a strong and independent predictor of mortality and disease progression in various diseases, including cardiovascular and pulmonary diseases. Furthermore, it is generally accepted that exercise capacity in healthy individuals and in patients suffering from cardiovascular diseases is mainly limited by the maximum cardiac output. Objectives: This thesis investigated the impact of different lung function indices on EC in healthy individuals, patients with cardiovascular disease (e.g., pulmonary hypertension (PH)) and patients with pulmonary disease (e.g., chronic obstructive pulmonary disease (COPD)). Methods: The present thesis is based on cross-sectional and longitudinal analyses of patients suffering from COPD, attending pulmonary rehabilitation at Uppsala University Hospital (studies I and II), and healthy men enrolled in the “Oslo ischemia study” (study IV). Study III is a cross-sectional study of patients suffering from PH attending the San Giovanni Battista University Hospital in Turin. EC was assessed using a bicycle ergometer in studies I and IV, with 12-minute walk tests (12MWT) in study II and with 6-minute walk tests (6MWT) in study III. Extensive pulmonary function tests, including diffusing capacity of the lung (DLCO), were performed in studies I-III and dynamic spirometry was used to assess lung function in study IV. Results: DLCO is more closely linked to decreased levels of EC than airway obstruction in COPD patients. Furthermore, the decline in 12MWT over a 5-year period was mainly explained by deterioration in DLCO in COPD patients. Spirometric parameters indicating airway obstruction significantly related to EC and exercise-induced desaturation in PH patients. A significant, but weak association between lung function parameters and EC was found in healthy subjects and this association is strengthened with increasing age. Conclusion: DLCO is the strongest predictor of low EC and EC decline in COPD. In PH, airway obstruction is strongly related to reduced 6MWT. Therefore, extensive analysis of lung function, including measurements of diffusing capacity, along with standard assessment of airway obstruction, gives a more comprehensive assessment of the functional exercise capacity in patients suffering from pulmonary hypertension or COPD. Lung function is also significantly linked to EC even in healthy subjects, lacking evident cardiopulmonary diseases.
3

Correlation between COPD and pulmonary hypertension

Haghighi, Maryam January 2005 (has links)
<p>Chronic obstructive pulmonary disease (COPD) is in up to 90 % of all cases caused by</p><p>smoking. COPD often has negative effects on circulation, effects that first and foremost can be</p><p>observed as respiratory insufficiency. Reduced function of the right ventricle of the heart is</p><p>common in patients suffering from chronic obstructive pulmonary disease, especially if they</p><p>also have hypoxemi; insufficient levels of oxygen in blood or tissue. The incidence of this</p><p>cardiac complication reduces the survival time. It is possible in chronic obstructive pulmonary</p><p>disease that the pressure in the pulmonary circulation gradually increases resulting in</p><p>pulmonary hypertension followed by a slow adaptation of the right ventricle by hypertrophy of</p><p>the myocardium.</p><p>To investigate a correlation between COPD and pulmonary hypertension COPD patients</p><p>were subjected to spirometry and ultrasound on heart.</p><p>Of 14 examined patients 5 had developed pulmonary hypertension. A correlation between</p><p>obstruction in the COPD- patients and an increase in left ventricular diameter was found.</p><p>DLCO (diffusion capacity) of the lungs is directly connected to PA (pulmonary arterial</p><p>pressure). The lower DLCO, the higher risk to develop pulmonary hypertension. However, we</p><p>could not find a significant correlation between COPD and pulmonary hypertension in this</p><p>study even if most patients had a decreased DLCO.</p>
4

Estudo das equações de referência dos parâmetros de função pulmonar em repouso e ao exercício em amostra de idosos hígidos da população brasileira / Studies of reference equations of pulmonary function parameters at rest and exercise in a sample of healthy elderly individuals of the Brazilian population

Nascimento, Juliana Martins Rocha do 19 December 2016 (has links)
Introdução: A diferenciação entre saúde e doença do sistema respiratório torna-se mais difícil devido à tendência de envelhecimento populacional e da necessidade de identificação das alterações próprias da senescência. Os testes de função pulmonar constituem ferramentas clínicas importantes para avaliação respiratória e sua interpretação está baseada em equações de referência derivadas de amostra de indivíduos saudáveis, que podem não expressar adequadamente o comportamento nesta faixa etária específica, dada a reduzida representatividade de indivíduos idosos nos estudos que postularam tais equações. Objetivo: Verificar a acurácia das equações de referência disponíveis para testes de função pulmonar e cardiopulmonar de esforço em relação aos valores obtidos em amostra de indivíduos idosos hígidos e o impacto clínico na interpretação funcional baseada nestas equações. Metodologia: Estudo prospectivo observacional transversal, com voluntários saudáveis, com idade igual ou superior a 65 anos, não tabagistas, urbanos. Em uma única visita, foram coletados dados demográficos, antropométricos e clínicos, seguidos da realização de provas de função pulmonar em repouso (espirometria, medidas de volumes pulmonares e difusão) e do teste cardiopulmonar de exercício máximo (TCPE). Os resultados obtidos foram comparados com os valores esperados de acordo com equações de referência rotineiramente utilizadas para a interpretação (teste-T pareado e avaliação de concordância pelo diagrama de Bland-Altman) e a frequência de casos fora das faixas previstas foi determinada. Novas equações de referência foram geradas por regressão linear múltipla. Resultados: Foram incluídos 95 indivíduos (55 mulheres), com idade (anos) 75 ± 6 (feminino) e 74±6 (masculino). Caracterizou-se diferença significativa entre as médias dos parâmetros de função pulmonar em repouso observados e previstos por pelo menos 2 das 3 equações testadas para CVF, VEF1, CPT, VR e difusão para ambos os sexos. O mesmo ocorreu para os parâmetros funcionais ao exercício (carga e VO2 no pico do esforço) para 3 de 4 equações testadas. Não houve homogeneidade de um autor específico em predizer com melhor acurácia os valores observados na amostra testada para todos os parâmetros funcionais em ambos os sexos. A frequência de classificação de parâmetros fora das faixas de referência foi elevada para todas as equações avaliadas. Novas equações de referência foram apresentadas a partir dos dados obtidos. Conclusões: A utilização das equações de referência existentes apresentou aplicabilidade limitada à amostra de idosos saudáveis estudada, gerando elevados índices de valores sub e superestimados, potencialmente comprometendo a sensibilidade e especificidade dos testes. Foram derivadas equações idade-específicas para uma amostra de idosos suadáveis brasileiros, visando contemplar as mudanças fisiológicas nesta faixa etária / Introduction: Differentiating between health and disease of the respiratory system becomes more challenging due to the tendency of population aging and the need to identify themselves senescence changes. Pulmonary function tests are important tools for respiratory evaluation. Its interpretation is based on reference equations derived from healthy people studies that possibly not accordingly express the behavior at this particular age group, due to the low representativity of elderly individuals in the studies that postulated such equations. Objective: To verify the accuracy of reference equations available for pulmonary function and cardiopulmonary exercise tests in comparison to values obtained in a sample of healthy elderly subjects and assess the clinical impact on functional interpretation based on these equations. Methodology: Cross-sectional observational prospective study in healthy volunteers, aged over 65 years, non-smokers, urban living. Demographic, anthropometric and clinical data, were collected and pulmonary function tests at rest (spirometry, lung volumes measures and diffusing capacity pulmonary), and the maximal cardiopulmonary exercise test (CPET) were performed. Results were compared to the expected values according to reference equations routinely used for interpretation (paired t-test and evaluation agreement by Bland-Altman plot) and the frequency of cases outside the reference ranges were determined. New reference equations elderly-specific were generated using multiple linear regression. Results: 95 subjects (55 women), age (years) 75 ± 6 (female) and 74 ± 6 (male) were included. Significant difference between the mean lung function parameters observed versus predicted by at least 2 of 3 tested equations for FVC, FEV1, TLC, RV for both sexes were identified. The same occured for exercise measurements (load and VO2 at peak exercise) for 3 of 4 tested equations. There was no homogeneity of a particular author to predict more accurately values observed in the sample tested for all functional parameters in both sexes. There was high rates of out of reference range classification for all evaluated equations. New elderly-specific reference equations were presented from the data obtained. Conclusions: The use of existing reference equations had limited applicability to the sample of healthy elderly studied, generating high rates of under and overestimated values, potentially compromising the sensitivity and specificity of the tests. Age-specific equations were derived from a sample of Brazilian healthy elderly, aiming to represent the physiological changes in this age group
5

Estudo das equações de referência dos parâmetros de função pulmonar em repouso e ao exercício em amostra de idosos hígidos da população brasileira / Studies of reference equations of pulmonary function parameters at rest and exercise in a sample of healthy elderly individuals of the Brazilian population

Juliana Martins Rocha do Nascimento 19 December 2016 (has links)
Introdução: A diferenciação entre saúde e doença do sistema respiratório torna-se mais difícil devido à tendência de envelhecimento populacional e da necessidade de identificação das alterações próprias da senescência. Os testes de função pulmonar constituem ferramentas clínicas importantes para avaliação respiratória e sua interpretação está baseada em equações de referência derivadas de amostra de indivíduos saudáveis, que podem não expressar adequadamente o comportamento nesta faixa etária específica, dada a reduzida representatividade de indivíduos idosos nos estudos que postularam tais equações. Objetivo: Verificar a acurácia das equações de referência disponíveis para testes de função pulmonar e cardiopulmonar de esforço em relação aos valores obtidos em amostra de indivíduos idosos hígidos e o impacto clínico na interpretação funcional baseada nestas equações. Metodologia: Estudo prospectivo observacional transversal, com voluntários saudáveis, com idade igual ou superior a 65 anos, não tabagistas, urbanos. Em uma única visita, foram coletados dados demográficos, antropométricos e clínicos, seguidos da realização de provas de função pulmonar em repouso (espirometria, medidas de volumes pulmonares e difusão) e do teste cardiopulmonar de exercício máximo (TCPE). Os resultados obtidos foram comparados com os valores esperados de acordo com equações de referência rotineiramente utilizadas para a interpretação (teste-T pareado e avaliação de concordância pelo diagrama de Bland-Altman) e a frequência de casos fora das faixas previstas foi determinada. Novas equações de referência foram geradas por regressão linear múltipla. Resultados: Foram incluídos 95 indivíduos (55 mulheres), com idade (anos) 75 ± 6 (feminino) e 74±6 (masculino). Caracterizou-se diferença significativa entre as médias dos parâmetros de função pulmonar em repouso observados e previstos por pelo menos 2 das 3 equações testadas para CVF, VEF1, CPT, VR e difusão para ambos os sexos. O mesmo ocorreu para os parâmetros funcionais ao exercício (carga e VO2 no pico do esforço) para 3 de 4 equações testadas. Não houve homogeneidade de um autor específico em predizer com melhor acurácia os valores observados na amostra testada para todos os parâmetros funcionais em ambos os sexos. A frequência de classificação de parâmetros fora das faixas de referência foi elevada para todas as equações avaliadas. Novas equações de referência foram apresentadas a partir dos dados obtidos. Conclusões: A utilização das equações de referência existentes apresentou aplicabilidade limitada à amostra de idosos saudáveis estudada, gerando elevados índices de valores sub e superestimados, potencialmente comprometendo a sensibilidade e especificidade dos testes. Foram derivadas equações idade-específicas para uma amostra de idosos suadáveis brasileiros, visando contemplar as mudanças fisiológicas nesta faixa etária / Introduction: Differentiating between health and disease of the respiratory system becomes more challenging due to the tendency of population aging and the need to identify themselves senescence changes. Pulmonary function tests are important tools for respiratory evaluation. Its interpretation is based on reference equations derived from healthy people studies that possibly not accordingly express the behavior at this particular age group, due to the low representativity of elderly individuals in the studies that postulated such equations. Objective: To verify the accuracy of reference equations available for pulmonary function and cardiopulmonary exercise tests in comparison to values obtained in a sample of healthy elderly subjects and assess the clinical impact on functional interpretation based on these equations. Methodology: Cross-sectional observational prospective study in healthy volunteers, aged over 65 years, non-smokers, urban living. Demographic, anthropometric and clinical data, were collected and pulmonary function tests at rest (spirometry, lung volumes measures and diffusing capacity pulmonary), and the maximal cardiopulmonary exercise test (CPET) were performed. Results were compared to the expected values according to reference equations routinely used for interpretation (paired t-test and evaluation agreement by Bland-Altman plot) and the frequency of cases outside the reference ranges were determined. New reference equations elderly-specific were generated using multiple linear regression. Results: 95 subjects (55 women), age (years) 75 ± 6 (female) and 74 ± 6 (male) were included. Significant difference between the mean lung function parameters observed versus predicted by at least 2 of 3 tested equations for FVC, FEV1, TLC, RV for both sexes were identified. The same occured for exercise measurements (load and VO2 at peak exercise) for 3 of 4 tested equations. There was no homogeneity of a particular author to predict more accurately values observed in the sample tested for all functional parameters in both sexes. There was high rates of out of reference range classification for all evaluated equations. New elderly-specific reference equations were presented from the data obtained. Conclusions: The use of existing reference equations had limited applicability to the sample of healthy elderly studied, generating high rates of under and overestimated values, potentially compromising the sensitivity and specificity of the tests. Age-specific equations were derived from a sample of Brazilian healthy elderly, aiming to represent the physiological changes in this age group
6

Avaliação da função autonômica cardíaca e sua relação com a capacidade funcional em pacientes com DPOC

Bonança, Adriana Mazzuco 27 February 2015 (has links)
Made available in DSpace on 2016-06-02T20:19:26Z (GMT). No. of bitstreams: 1 6645.pdf: 2027088 bytes, checksum: 18fe5648e0835cf1cfcbef303f079520 (MD5) Previous issue date: 2015-02-27 / Universidade Federal de Sao Carlos / In chronic obstructive pulmonary disease (COPD), functional and structural impairment of lung function can negatively impact heart rate variability (HRV); in addition, a reduced exercise capacity is an important independent prognostic marker in COPD patients. However, 1) if the degree of lung impairment negatively impacts HRV responses and 2) whether the injury of the autonomic control may be associated with reduced exercise capacity in patients with COPD remain unclear. Thus, two studies were conducted in order to verify if functional status at rest and during exercise would be related to autonomic impairment in COPD patients. In the first study, entitled "Relationship between linear and nonlinear dynamics of heart rate and impairment of lung function in COPD patients," we investigated whether the impairment static lung volumes and lung diffusion capacity (DL) would be related to HRV indices in moderate-to-severe COPD. Sixteen patients with COPD underwent pulmonary function tests (spirometry, plethysmography and lung diffusion capacity for carbon monoxide - DLCO). The RR interval was registered in the supine, standing and seated positions and during a respiratory sinus arrhythmia maneuver (M-RSA). Our results suggest that responses of HRV indices were more prominent during M-RSA in moderate-to-severe COPD. Moreover, greater lung function impairment was related to poorer heart rate dynamics. Finally, impaired DLCO is related to an altered parasympathetic response in these patients. The second study, entitled "Are linear and nonlinear heart rate dynamics in submaximal exercise related to cardiorespiratory responses during maximal exercise in patients with COPD?", we inquired whether there is a relationship between HRV responses and exercise capacity in patients with COPD. Fifteen patients underwent incremental cardiopulmonary exercise testing and six-minute walk test (6MWT). The RR interval was registered at rest (standing position) and during 6MWT. Our results showed that HRV responses at rest and during simple field tests may reflect functional impairment of COPD patients, providing important information about both ventilatory and hemodynamic inefficiency in these patients. / Em pacientes com doença pulmonar obstrutiva crônica (DPOC), as alterações funcionais e estruturais do pulmão podem impactar negativamente na variabilidade da frequência cardíaca (VFC). Além disso, a reduzida capacidade de exercício se traduz como um marcador prognóstico nesses pacientes. No entanto, ainda não estão esclarecidos 1) se o grau de comprometimento pulmonar tem impacto negativo sobre as respostas da VFC, frente a diferentes estímulos autonômicos, e 2) se o prejuízo no controle autonômico pode estar relacionado à reduzida capacidade de exercício nos pacientes com DPOC. Sendo assim, dois estudos foram realizados com o intuito de relacionar as alterações funcionais, no repouso e no exercício, com o grau de prejuízo autonômico em pacientes com DPOC. O primeiro estudo, cujo título é Correlação entre as dinâmicas linear e não linear da frequência cardíaca e o comprometimento da função pulmonar em pacientes com DPOC , teve como objetivo investigar se o comprometimento nos volumes pulmonares estáticos e na difusão pulmonar estaria relacionado aos índices da VFC em repouso e em resposta às mudanças posturais. Dezesseis pacientes com diagnóstico de DPOC foram submetidos à prova de função pulmonar (espirometria, pletismografia e capacidade de difusão pulmonar ao monóxido de carbono DCO) e à coleta da VFC nas posturas supino, ortostatismo e sentado e durante a manobra de arritmia sinusal respiratória (M-ASR). Nossos resultados sugerem que as respostas da VFC frente a um estímulo vagal (M-ASR) são mais evidentes. Ainda, quanto maior o comprometimento da função pulmonar pior a dinâmica da frequência cardíaca. Por fim, a redução da DCO está relacionada à alterada resposta vagal nos pacientes com DPOC. O segundo estudo, intitulado Os índices da dinâmica linear e não linear na frequência cardíaca no exercício submáximo estão relacionados com as respostas cardiorrespiratórias ao exercício máximo em pacientes com DPOC? teve por objetivo avaliar se existe relação entre as respostas da VFC e a capacidade de exercício em pacientes com DPOC. Quinze pacientes foram submetidos aos testes de exercício cardiopulmonar incremental e de caminhada de seis minutos (TC6). A coleta da VFC feita em repouso (ortostatismo) e durante o TC6. Os resultados mostraram que as respostas da VFC no repouso e em testes simples de campo podem inferir o prejuízo funcional de pacientes com DPOC, fornecendo informações importantes acerca das limitações ventilatória e hemodinâmica destes pacientes.
7

Pracoviště pro měření náhradního schématu fotovoltaických článků / Workplace for measurement of substitute scheme of Photovoltaic cells

Klein, Radek January 2008 (has links)
The subject of this diploma thesis is to analyse solar cells, demonstrate linearized model of PN junction and show basic techniques of measurement of this model. Solar cells measurement and acquired results are also presented.
8

Pracoviště pro dynamické testování solárních článků / Worpllace for dynamic testring of solar cells.

Hanák, Kamil January 2009 (has links)
This work deals with method for characterization of photovoltaic solar cells based on evaluation of solar cell response to fast transients. The voltage of the cell in both forward and reverse polarisation was controlled by current pulse exciting. Real reverse breakdown voltage and exact value of serial resistance of the cell can be obtained easily by evaluation of the transient curves recorded by digital osciloscope. By negotiation of the time constants of the cell response to excitation in forward polarisation the lifetime of minority carriers in semiconductor bulk can be estimated.
9

Echocardiography for the noninvasive study of the pulmonary circulation: applications to the study of right ventricular effects of targeted therapies of pulmonary hypertension, limiting factors to exercise capacity, and detection of early pulmonary vascular disease in healthy subjects / Apport de l'échocardiographie dans l'étude non invasive de la circulation pulmonaire: (1) étude pharmacologique, (2) étude des facteurs limitant l'aptitude aérobie, (3) étude sur l'identification de l'hypertension artérielle pulmonaire latente

Pavelescu, Adriana 08 October 2012 (has links)
Ce travail a été consacré à l’étude non invasive de la circulation pulmonaire normale par mise en œuvre de l’échocardiographie Doppler. <p>En intégrant les mesures obtenues dans une approche physiopathologique, et en exploitant les nouvelles possibilités d’échocardiographes portables, techniquement performants, nous avons analysé les effets d’un inhibiteur de la phosphodiestérase-5 et d’une prostacycline, pour tenter d’en identifier d’éventuels effets introtropes intrinsèques, nous avons exploré le concept de réserve vasculaire pulmonaire comme facteur limitant de l’aptitude aérobie et indice potentiel d’une atteinte vasculaire pulmonaire précoce, et obtenu des résultats préliminaires permettant d’identifier une hypertension artérielle pulmonaire (HTAP) latente. Nos principaux résultats peuvent être résumés comme suit :<p>1. Chez le sujet sain, en normoxie ou dans un modèle expérimental d’HTAP induite par l’inhalation d’un mélange gazeux hypoxique, le sildenafil per os ou l’epoprostenol par voie intraveineuse, à des doses utilisées en clinique pour le traitement de l’HTAP, améliorent les indices de la fonction ventriculaire droite en proportion de leurs effets vasodilatatoires pulmonaires, sans effets inotropes intrinsèques détectables.<p>2. La consommation d’oxygène maximale du sujet sain augmente en raison directe de son volume capillaire pulmonaire (calculé à partir de sa capacité de diffusion pour l’oxyde nitrique et le monoxyde de carbone) et en raison inverse de sa résistance vasculaire pulmonaire, non seulement en altitude, mais aussi au niveau de la mer. Ce résultat suggère qu’une plus grande réserve vasculaire pulmonaire est propice aux efforts aérobiques intenses, probablement par moindre postcharge ventriculaire droite.<p>3. Des mesures réalisées chez un petit nombre de sujets suggèrent que la distensibilité vasculaire pulmonaire, calculée à partir d’une relation débit-pression vasculaire pulmonaire, est typiquement réduite chez des porteurs asymptomatiques de la mutation BMPR2, qui est actuellement le facteur de risque le plus élevé connu de l’HTAP. La mutation BMPR2 pourrait aussi être associée à une réactivité vasculaire pulmonaire accrue à l’hypoxie. <p>Nos résultats suggèrent indirectement que l’échocardiographie Doppler, de repos ou de stress, pourrait être davantage développée dans la mise au point de patients à risque d’HTAP./<p><p>Novel advances in echocardiography offer the opportunity to reliably characterize pulmonary circulation in terms of pressure-flow relationship, and to better understand the coupling of right ventricular (RV) function with normal and abnormal pulmonary hemodynamics. Moreover, when combined with the measurement of pulmonary capillary blood volume, this renewed methodological approach may help to understand the concept of pulmonary vascular reserve as a limiting factor of exercise capacity and potential sensitive marker of early vascular disease.<p><p>In the present work we used a model of hypoxic pulmonary vasoconstriction to analyse the effects of two targeted therapies of pulmonary arterial hypertension (PAH) on the RV function. We showed that the beneficial effects of these drugs are mainly driven by a decrease in RV afterload and not an enhanced myocardial inotropic state. Whether this is transposable to abnormal RV-arterial coupling in PAH patients remains to be investigated.<p><p>Echocardiography may be useful to explore the pulmonary vascular reserve as an important limiting factor of exercise capacity. We showed that a higher pulmonary vascular reserve, defined by a decreased PVR and increased lung diffusing capacity, allows for an improved aerobic exercise capacity (as assessed by a higher peak oxygen consumption), at a lower ventilatory cost, at sea level and at high altitude. <p><p>Stress echocardiography may detect an abnormal pulmonary vasoreactivity. We showed that asymptomatic relatives of patients suffering from idiopathic pulmonary arterial hypertension, and who carry a bone morphogenetic protein receptor type 2 mutation (BMPR2) present with a decreased pulmonary vascular distensibility and an enhanced pulmonary vasoreactivity to hypoxia, which are identifiable by echocardiography examination. However, the predictive value of these findings is not known. <p><p>Thus echocardiography may represent, in experienced and dedicated hands, a noninvasive, safe, widely available, applicable at the bed-side as well as in extreme environment (e.g. high altitudes), less expensive alternative for the evaluation of the pulmonary circulation, either by the interrogation of pressure-flow relationship (stress echocardiography), by the investigation of the right ventricle global and regional function in relation to its afterload (standard and Tissue Doppler Imaging), or by a combined approach with the measurement of lung diffusing capacity (DLNO / DLCO) to assess the pulmonary vascular reserve.<p><p>The present data are encouraging for further development and implementation of echocardiography for the detection, but also the diagnosis and follow-up of patients with pulmonary hypertension.<p><p> / Doctorat en Sciences médicales / info:eu-repo/semantics/nonPublished

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