• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 536
  • 266
  • 78
  • 72
  • 49
  • 46
  • 27
  • 14
  • 14
  • 9
  • 9
  • 9
  • 9
  • 9
  • 9
  • Tagged with
  • 1397
  • 336
  • 303
  • 200
  • 187
  • 175
  • 153
  • 150
  • 139
  • 126
  • 122
  • 116
  • 106
  • 92
  • 91
  • 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.
281

Esquerdismo na América Latina (2002-2008): o racha à esquerda no Frente Amplio em perspectiva comparada com o racha à esquerda no Partido dos Trabalhadores / Leftism in the Latin American (2002-2008): the split in the left of the Frente Amplio in comparative perspective to the split in the left of the Partido dos Trabalhadores

Piedrabuena, Bruno Gastón Vera 13 March 2017 (has links)
O objetivo desta dissertação é construir uma hipótese de mecanismo causal do esquerdismo nos governos de esquerda renovadora da América Latina a partir do estudo de caso do racha à esquerda do Frente Amplio (FA) do Uruguai, e testar esta hipótese com o caso do racha à esquerda do Partido dos Trabalhadores (PT) do Brasil. Utilizando theory building process-tracing, a partir da literatura sobre partidos políticos foram elaboradas, e testadas no caso uruguaio, três hipóteses de partes de mecanismo causal, as quais estabelecem: (i) o movimento ao centro feito pelo FA para atingir objetivos eleitorais é parte do mecanismo causal do racha da fração 26M; (ii) as situações de crise com o governo do Presidente Tabaré Vázquez se constituíram em parte do mecanismo causal do racha do 26M; e (iii), a diminuição das oportunidades do 26M de incidir na toma de decisões do FA, combinada com sua perda de zonas de incerteza dentro do partido, tornou- se parte do mecanismo causal do racha desta fração. As evidências apresentadas para cada hipótese suportaram o Hoop test, o que deu um alto poder confirmatório das hipóteses, porém, não permitiu descartar hipóteses alternativas. Com base nos resultados do caso Uruguaio, se construiu uma hipótese de mecanismo causal dos processos de esquerdismo nos governos de esquerda renovadora da América Latina que contém 8 partes, as entidades (atores) e ações envolvidas em cada uma delas. Por fim, utilizando theory-testing process-tracing, se fizeram apontamentos sobre o funcionamento da hipótese no caso do processo das frações que racharam com o PT e formaram o Partido Socialismo e Liberdade (PSOL). As evidências apresentadas neste caso não foram submetidas a testes empíricos, porém, de maneira geral, não diminuíram nossa confiança na hipótese de mecanismo causal. Inclusive, se produzindo uma trajetória divergente entre as frações que derivou na estruturação em dois momentos do PSOL, não foi necessário adicionar de maneira ad-hoc partes para o mecanismo, pois as foças causais foram transmitidas pelas partes nele estabelecidas, encurtando-o no caso das frações que racharam no primeiro momento, e percorrendo-o parte por parte, no caso da fração que rachou no segundo momento. / The aim of this Master\'s dissertation is to construct a causal mechanism hypothesis of leftism in the Latin American renovation of left-wing governments. This will be reviewed in two parts: starting with the case study of the split in the left of the Frente Amplio (FA) party of Uruguay, and furthermore to test the hypothesis with the case study of the split in the left of the Partido dos Trabalhadores (PT) of Brazil. Using theory- building process-tracing from literature about political parties, three hypotheses of parts of causal mechanism were elaborated and tested in the Uruguayan case, which established that: (i) the movement towards the center made by the FA to achieve electoral objectives was part of the causal mechanism of the split of the fraction 26M; (ii) crisis situations with the government of President Tabaré Vázquez were part of the causal mechanism of the split of 26M; and (iii) the reduction of 26M\'s opportunities to influence FA decision-making process, combined with the loss of zones of uncertainty within the party, became part of the causal mechanism of fracture of this fraction. The evidences presented for each hypothesis withstood the Hoop test, which gave a high confirmatory power to the hypotheses, however, they did not allow for the disregard of alternative hypotheses. Based on the results in the case of Uruguay, a hypothesis of causal mechanism of the leftist processes in the Latin American renovation of left-wing governments was constructed, which contains 8 parts, the entities (actors) and actions involved in each one of them. Finally, using theory-testing process-tracing, notes were made on the functionality of the hypothesis in the process of fractions that broke with the PT and formed the Partido Socialismo e Liberdade (PSOL). The evidence presented in this case was not subjected to empirical tests, however, in general, it did not diminish our confidence in the causal mechanism hypothesis. Even if there was a divergent trajectory between the fractions that resulted in the structuring in two moments of PSOL, it was not necessary to add parts to the mechanism ad-hoc, because the causal forces were transmitted to the parties in it, shortening it in the case of the fractions that broke initially, and going part by part, in the case of the fraction that broke after.
282

Of Unprincipled Formalism: Readings in the Work of David Malouf and Peter Carey

Baker, David, n/a January 2003 (has links)
This thesis develops a critical reading methodology entitled unprincipled formalism. This methodology is tested in close readings of three relatively contemporary Australian literary texts: David Malouf's short story "A Traveller's Tale" (1986) and novella Remembering Babylon (1994), and Peter Carey's short story "The Chance" (1978). Unprincipled formalism is developed in relation to three broad contexts: the fragmented state of the contemporary discipline of literary studies; the complex of international economic and social phenomena which goes under the general rubric of globalisation; and the specific Australian left-liberal literary critical tradition which I have termed, for convenience sake, the Meanjin literary formation. Unprincipled formalism does not draw a distinction between form and content. Unprincipled formalism is a critical methodology that is both avowedly socially concerned and strictly formalist. It is concerned with articulating and analysing the particular social and political interventions made by literary texts (as well as the resultant critical discussion of those texts) through a consideration of the formal techniques by which literary texts situate themselves as acts of communication. Principal among these techniques is the mise en abyme. The thesis provides a detailed analysis of debates around the mise en abyme informed by the work of theorists such as Ross Chambers, Lucien Dallenbach, Frank Lentricchia, Moshe Ron, Jacques Derrida and others. Politically, unprincipled formalism attempts to steer a middling course between neo-liberal triumphalism on the one hand and nostalgic left romanticism on the other. This involves on the one hand a critique of neo-liberalism drawing on the work of Charles Taylor, Stephen Holmes, John Frow and others, and on the other a critique of a nostalgic romantic tendency in "progressive" critical technologies such as postmodern and postcolonial literary studies.
283

Theoretical Investigation Of Metamaterials: Srr Structures And Periodic Arrays Of Thin Conducting Wires

Ates, Kazim Ozan 01 May 2008 (has links) (PDF)
In recent years, there has been an increasing interest on left handed metamaterials because of their possible innovative applications. The pioneer study introducing such materials was brought out by V. G. Veselago in 1968 [1]. In his work, Veselago proposed a medium having simultaneously negative electric permittivity and magnetic permeability and investigated its electromagnetic characteristics. He found out that the electric field, magnetic field and the propagation vector form a left handed triplet, thus named such materials as &ldquo / Left Handed Materials&rdquo / . Despite the significance of Veselago&rsquo / s inferences, the metamaterial theory stayed dormant for nearly 30 years. Towards the end of 1990s, the physically realizable left handed materials were built as the combination of two periodical structures / Split Ring Resonators (SRRs) and metallic thin wire arrays [4-5]. In this thesis, electrical and magnetic characteristics of the left handed metamaterials are theoretically investigated by using the analytical models for their permittivity and permeability functions with respect to frequency. For this purpose, first, two basic metamaterial structures / the Split Ring Resonators and Thin Metallic Wire Arrays are studied individually and their electrical and magnetic characteristics are examined. Finally, the composite left handed structure containing both SRRs and thin wires is studied to investigate the resulting simultaneous resonance properties and to estimate their overall effective permeability and permittivity functions.
284

Why laterality matters in trauma : sinister aspects of memory and emotion

Choudhary, Carolyn J. January 2008 (has links)
This thesis presents an eclectic mix of studies which consider laterality in the context of previous findings of increased prevalence of Posttraumatic Stress Disorder (PTSD) in male combat veterans with non-consistent right hand preference. Two studies extend these findings not just to civilian populations and women, but to left handers and find that left, rather than mixed, handedness is associated with increased prevalence of PTSD in both general population and clinical samples, and to severity of symptoms in the former. To examine issues relevant to the fear response in healthy populations, a movie excerpt is shown to be theoretically likely to target the emotion of fear and to generate subjective and physiological (skin conductance) responses of fear. The film is used as a laboratory analogue of fear to examine possible differences in left and right handers in memory (for events of the film) and in an emotional Stroop paradigm known to produce a robust and large effect specifically in PTSD. According to predictions based on lateralisation of functions in the brain relevant to the fear response, left handers show a pattern of enhanced memory for visual items and poorer memory for verbal material compared to right handers. Immediately after viewing the film, left handers show an interference effect on the Stroop paradigm to general threat and film words and increased response latency compared to right handers, approaching performance of previously reported clinical samples with PTSD. A novel non-word Stroop task fails to show these effects, consistent both with accounts of interference as language processing effects and compromised verbal processing in PTSD. Unexpected inferior performance of females in memory for the film, contrary to previous literature, may also be amenable to explanations invoking compromised left hemisphere language functions in fear situations. In testing one theory of left handedness as due to increased levels of in utero testosterone, the 2D:4D (second to fourth digit ratio) provides mixed evidence in two samples. A possible association of more female-like digit ratios in males with PTSD is a tentative finding possibly relevant to sex differences in prevalence of PTSD. A critique of existing and inadequate theoretical accounts of handedness concludes the thesis and proposes a modification of the birth stress hypothesis to one specifically considering peri-natal trauma to account for the above findings. This hypothesis remains to be empirically tested.
285

Noninvasive evaluation of the effects of coronary artery bypass grafting on myocardial function /

Hedman, Anders, January 2006 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 4 uppsatser.
286

La cattiva strada : linguaggi, scenari e rappresentazioni della protesta giovanile tra usa ed europa nel lungo sessantotto / La mauvaise route : langages, scénarios et représentations de la contestation juvénile des « longues années 68 » entre l’Europe et les Etats-Unis / The bad road : languages, scenarios and representations of the "long Sixties" juvenile challenge between Europe and the United States

Fucci, Carolina 06 June 2015 (has links)
Centrée sur le contexte des « longues années 68 », la thèse porte sur les raisons et le déroulement de la protestation juvénile entre les Etats-Unis et l’Europe, à partir du début des années Soixante jusqu’à la moitié de la décennie suivante. Il s’agit d’une période durant laquelle les pays développés connaissent une transformation sans pareil, marquée par l’élargissement de la société de consommation de masse et par le progrès frappant dans le domaine de la communication. La recherche vise surtout à éclairer deux questions principales : définir le rôle joué par la contre-culture dans la vague révolutionnaire et encadrer la dimension internationale du mouvement. Ce travail est donc divisé en deux parties : la première aborde les causes et l’esprit de la contre-culture à partir de ses racines américaines, tandis que la deuxième partie sera centrée sur les agitations étudiantes dans les pays de référence. En ce qui concerne les acteurs de la mobilisation, la recherche porte sur trois sujets principaux : les groupes undergrounds, le mouvement étudiant international et la révolte italienne de Soixante-dix-sept. Il s’agit de trois sujets qui représentent trois phases distinctes dans la chronologie du « cycle de protestation », un cycle qui se déroule dans un récit déchiqueté où on assiste à un changement continu de paradigme. Malgré cette inconstance fondamentale, il subsiste des mots d’ordre qui occupent une place privilégiée dans la mentalité des activistes : anti-autoritarisme, égalitarisme, répression, droit, révolution restent les nœuds théoriques les plus significatifs de la contestation dans le milieu juvénile, étudiant et également ouvrier. / Centred on the political and cultural context of the “long Sixties”, this work examines the reasons and the dynamics of social movements between USA and Europe, focusing on the period from 1960 to the mid-1970s. It was a period of great transformations where the affluent societies witnessed an explosive growth both in social field and in technological domain. This thesis aims above all to understand two main issues: the role counterculture played in the war protest and civil rights movement and the international dimension of this phenomenon. Thus, this research is divided into two parts: the first section concerns with the underground movement beginning with its American roots while the second part is dedicated to the student movement thought an international perspective. Concerning the social actors involved in the mobilisation, this work is focused on three main subjects: the counterculture groups, the several student movements and the militants of Italian 1977 revolt. It means to analyse three different moments in the “protestation cycle” of long Sixties that remains a tumultuous period of paradigm shifts. In spite of this instability, it is possible to indicate some keywords that characterise the spirit of the age: anti-authoritarianism, egalitarianism, repression, rights, and above all, revolution remain the more significant theoretical questions on which this work revolves.
287

Resposta anormal da função sistólica do ventrículo esquerdo ao exercício submáximo em pacientes submetidos à ventriculectomia parcial esquerda / Abnormal response of left ventricular systolic function to submaximal exercise in post-partial left ventriculectomy patients

Herdy, Artur Haddad January 2002 (has links)
Introdução. Pacientes com insuficiência cardíaca submetidos à ventriculectomia parcial esquerda apresentam melhora na função sistólica do ventrículo esquerdo em repouso, porém continuam apresentando limitação funcional. Objetivo. Para melhor compreender os mecanismos desta limitação funcional, estudamos a função sistólica e diastólica do ventrículo esquerdo em repouso e durante exercício submáximo em pacientes submetidos a ventriculectomia parcial esquerda e em pacientes com insuficiência cardíaca não operados, pareados para capacidade funcional máxima e submáxima. Métodos. Foram estudados 9 pacientes submetidos previamente a ventriculografia parcial esquerda (VPE) e 9 pacientes com insuficiência cardíaca não operados previamente (IC). Todos os pacientes foram submetidos inicialmente a um teste cardiopulmonar para determinação do consumo de oxigênio no limiar anaeróbio (LA) e de pico (VO2 pico). Após, foram estudados através da ventriculografia radioisotópica e analisadas a fração de ejeção (FE) e a taxa máxima de enchimento (TME) do ventrículo esquerdo, em repouso e exercício na intensidade do LA. Resultados. Os grupos apresentaram capacidade funcional semelhante avaliada pelo VO2 pico (VPE: [média ± DP] 13,1 ± 3,3 ml/kg.min; IC: 14,1 ± 3,6 ml/kg.min; P > 0,05) e LA (VPE: 7,9 ± 1.3 ml/kg.min; IC: 8,5 ± 1,6 ml/kg.min; P > 0,05). A frequência cardíaca máxima foi maior no grupo IC em comparação ao grupo da VPE (VPE: 119 ± 20 bpm; IC: 149 ± 21 bpm; P < 0.05) A FE em repouso era mais elevada no grupo VPE (VPE: 40 ± 12 %; IC: 32 ± 9 %; P < 0,0125), entretanto a FE elevou-se do repouso ao LA apenas no grupo IC (VPE: 44 ± 17 %; IC: 39 ± 11 %; P < 0,0125). A TME foi semelhante em repouso (VPE: 1,41 ± 0,55 VDF/s; IC: 1,39 ± 0,55 VDF/s; P > 0,05) e aumentou na intensidade do LA similarmente em ambos os grupos (VPE: 2,28 ± 0,55 VDF/s; IC: 2,52 ± 1,07 VDF/s; P < 0,0125). Conclusão. Pacientes submetidos a ventriculectomia parcial esquerda apresentam uma o limiar anaeróbio (LA) resposta anormal da função sistólica do ventrículo esquerdo ao exercício na intensidade do LA e uma resposta cronotrópica diminuida ao exercício máximo. Essas respostas anormais podem contribuir para a limitada capacidade ao exercício destes pacientes, a despeito da melhora na função ventricular sistólica em repouso. / Background. Patients with heart failure who have undergone partial left ventriculectomy improve resting left ventricular systolic function, but maintain limited functional capacity. Objective. In order to better understand the mechanisms associated with this limitation, we studied the systolic and diastolic left ventricular function at rest and during submaximal exercise in patients with previous partial left ventriculectomy and in patients with heart failure who had not been operated, matched for maximal and submaximal exercise capacity. Methods: Nine patients with heart failure who were previously submitted to partial left ventriculectomy (PLV) were compared with a group of 9 patients with heart failure who had not been operated. All patients performed a cardiopulmonary exercise testing with measurement of peak oxygen uptake (VO2 peak) and anaerobic threshold (AT). In a second evaluation, radionuclide left ventriculography was performed to analyze ejection fraction (EF) and peak filling rate (PFR) at rest and during exercise at the intensity corresponding to the AT. Results: Groups presented similar exercise capacity evaluated by VO2peak (PLV: [mean ± SD] 13.1 ± 3.3 mL/Kg.min; HF: 14.1 ± 3.6 mL/Kg.min; P > 0.05) and AT (PLV: 7.9 ± 1.3 mL/Kg.min; HF: 8.5 ± 1.6 mL/Kg.min; P > 0.05). Maximal heart rate was higher in the HF group when compared to the PLV group (PLV: 119 ± 20 bpm; HF: 149 ± 21 bpm; P < 0.05). EF at rest was higher in the PLV group (PLV: 40 ± 12 %; HF: 32 ± 9 %; P < 0.0125), however EF increased from rest to AT only in the HF group (PLV: 44 ± 17 %; HF: 39 ± 11 %; P < 0.0125). PFR was similar at rest (PLV: 1.41 ± 0.55 EDV/sec; HF: 1.39 ± 0.55 EDV/sec; P > 0.05) and increased in both groups at the AT intensity (PLV: 2.28 ± 0.55 EDV/sec; HF: 2.52 ± 1.07 EDV/sec; P < 0,0125). Conclusion: Patients who had partial left ventriculectomy present an abnormal response of left ventricular systolic function to exercise at the AT intensity and an impaired chronotropic response to maximal exercise. These abnormal responses may contribute to the limited exercise capacity of these patients, despite the improvement in resting left ventricular systolic function.
288

Resposta anormal da função sistólica do ventrículo esquerdo ao exercício submáximo em pacientes submetidos à ventriculectomia parcial esquerda / Abnormal response of left ventricular systolic function to submaximal exercise in post-partial left ventriculectomy patients

Herdy, Artur Haddad January 2002 (has links)
Introdução. Pacientes com insuficiência cardíaca submetidos à ventriculectomia parcial esquerda apresentam melhora na função sistólica do ventrículo esquerdo em repouso, porém continuam apresentando limitação funcional. Objetivo. Para melhor compreender os mecanismos desta limitação funcional, estudamos a função sistólica e diastólica do ventrículo esquerdo em repouso e durante exercício submáximo em pacientes submetidos a ventriculectomia parcial esquerda e em pacientes com insuficiência cardíaca não operados, pareados para capacidade funcional máxima e submáxima. Métodos. Foram estudados 9 pacientes submetidos previamente a ventriculografia parcial esquerda (VPE) e 9 pacientes com insuficiência cardíaca não operados previamente (IC). Todos os pacientes foram submetidos inicialmente a um teste cardiopulmonar para determinação do consumo de oxigênio no limiar anaeróbio (LA) e de pico (VO2 pico). Após, foram estudados através da ventriculografia radioisotópica e analisadas a fração de ejeção (FE) e a taxa máxima de enchimento (TME) do ventrículo esquerdo, em repouso e exercício na intensidade do LA. Resultados. Os grupos apresentaram capacidade funcional semelhante avaliada pelo VO2 pico (VPE: [média ± DP] 13,1 ± 3,3 ml/kg.min; IC: 14,1 ± 3,6 ml/kg.min; P > 0,05) e LA (VPE: 7,9 ± 1.3 ml/kg.min; IC: 8,5 ± 1,6 ml/kg.min; P > 0,05). A frequência cardíaca máxima foi maior no grupo IC em comparação ao grupo da VPE (VPE: 119 ± 20 bpm; IC: 149 ± 21 bpm; P < 0.05) A FE em repouso era mais elevada no grupo VPE (VPE: 40 ± 12 %; IC: 32 ± 9 %; P < 0,0125), entretanto a FE elevou-se do repouso ao LA apenas no grupo IC (VPE: 44 ± 17 %; IC: 39 ± 11 %; P < 0,0125). A TME foi semelhante em repouso (VPE: 1,41 ± 0,55 VDF/s; IC: 1,39 ± 0,55 VDF/s; P > 0,05) e aumentou na intensidade do LA similarmente em ambos os grupos (VPE: 2,28 ± 0,55 VDF/s; IC: 2,52 ± 1,07 VDF/s; P < 0,0125). Conclusão. Pacientes submetidos a ventriculectomia parcial esquerda apresentam uma o limiar anaeróbio (LA) resposta anormal da função sistólica do ventrículo esquerdo ao exercício na intensidade do LA e uma resposta cronotrópica diminuida ao exercício máximo. Essas respostas anormais podem contribuir para a limitada capacidade ao exercício destes pacientes, a despeito da melhora na função ventricular sistólica em repouso. / Background. Patients with heart failure who have undergone partial left ventriculectomy improve resting left ventricular systolic function, but maintain limited functional capacity. Objective. In order to better understand the mechanisms associated with this limitation, we studied the systolic and diastolic left ventricular function at rest and during submaximal exercise in patients with previous partial left ventriculectomy and in patients with heart failure who had not been operated, matched for maximal and submaximal exercise capacity. Methods: Nine patients with heart failure who were previously submitted to partial left ventriculectomy (PLV) were compared with a group of 9 patients with heart failure who had not been operated. All patients performed a cardiopulmonary exercise testing with measurement of peak oxygen uptake (VO2 peak) and anaerobic threshold (AT). In a second evaluation, radionuclide left ventriculography was performed to analyze ejection fraction (EF) and peak filling rate (PFR) at rest and during exercise at the intensity corresponding to the AT. Results: Groups presented similar exercise capacity evaluated by VO2peak (PLV: [mean ± SD] 13.1 ± 3.3 mL/Kg.min; HF: 14.1 ± 3.6 mL/Kg.min; P > 0.05) and AT (PLV: 7.9 ± 1.3 mL/Kg.min; HF: 8.5 ± 1.6 mL/Kg.min; P > 0.05). Maximal heart rate was higher in the HF group when compared to the PLV group (PLV: 119 ± 20 bpm; HF: 149 ± 21 bpm; P < 0.05). EF at rest was higher in the PLV group (PLV: 40 ± 12 %; HF: 32 ± 9 %; P < 0.0125), however EF increased from rest to AT only in the HF group (PLV: 44 ± 17 %; HF: 39 ± 11 %; P < 0.0125). PFR was similar at rest (PLV: 1.41 ± 0.55 EDV/sec; HF: 1.39 ± 0.55 EDV/sec; P > 0.05) and increased in both groups at the AT intensity (PLV: 2.28 ± 0.55 EDV/sec; HF: 2.52 ± 1.07 EDV/sec; P < 0,0125). Conclusion: Patients who had partial left ventriculectomy present an abnormal response of left ventricular systolic function to exercise at the AT intensity and an impaired chronotropic response to maximal exercise. These abnormal responses may contribute to the limited exercise capacity of these patients, despite the improvement in resting left ventricular systolic function.
289

Investigation into whether some key properties of BN under addition also apply in BN under multiplication and elaboration of some properties of the smallest ideal of a semigroup

Mweete, Kapaipi Hendrix 08 1900 (has links)
This dissertation will seek to explore if the properties of some of the key results on semigroups and their compacti cations under the operation of addition also apply under the operation of multiplication. Consider- able emphasis will be placed on the semigroup N of the set of natural numbers and its compacti cation N. Furthermore, the dissertation will discuss the smallest ideal of a semi- group and highlight some of its fundamental properties. / Mathematics / M. Sc. (Mathematics)
290

Resposta anormal da função sistólica do ventrículo esquerdo ao exercício submáximo em pacientes submetidos à ventriculectomia parcial esquerda / Abnormal response of left ventricular systolic function to submaximal exercise in post-partial left ventriculectomy patients

Herdy, Artur Haddad January 2002 (has links)
Introdução. Pacientes com insuficiência cardíaca submetidos à ventriculectomia parcial esquerda apresentam melhora na função sistólica do ventrículo esquerdo em repouso, porém continuam apresentando limitação funcional. Objetivo. Para melhor compreender os mecanismos desta limitação funcional, estudamos a função sistólica e diastólica do ventrículo esquerdo em repouso e durante exercício submáximo em pacientes submetidos a ventriculectomia parcial esquerda e em pacientes com insuficiência cardíaca não operados, pareados para capacidade funcional máxima e submáxima. Métodos. Foram estudados 9 pacientes submetidos previamente a ventriculografia parcial esquerda (VPE) e 9 pacientes com insuficiência cardíaca não operados previamente (IC). Todos os pacientes foram submetidos inicialmente a um teste cardiopulmonar para determinação do consumo de oxigênio no limiar anaeróbio (LA) e de pico (VO2 pico). Após, foram estudados através da ventriculografia radioisotópica e analisadas a fração de ejeção (FE) e a taxa máxima de enchimento (TME) do ventrículo esquerdo, em repouso e exercício na intensidade do LA. Resultados. Os grupos apresentaram capacidade funcional semelhante avaliada pelo VO2 pico (VPE: [média ± DP] 13,1 ± 3,3 ml/kg.min; IC: 14,1 ± 3,6 ml/kg.min; P > 0,05) e LA (VPE: 7,9 ± 1.3 ml/kg.min; IC: 8,5 ± 1,6 ml/kg.min; P > 0,05). A frequência cardíaca máxima foi maior no grupo IC em comparação ao grupo da VPE (VPE: 119 ± 20 bpm; IC: 149 ± 21 bpm; P < 0.05) A FE em repouso era mais elevada no grupo VPE (VPE: 40 ± 12 %; IC: 32 ± 9 %; P < 0,0125), entretanto a FE elevou-se do repouso ao LA apenas no grupo IC (VPE: 44 ± 17 %; IC: 39 ± 11 %; P < 0,0125). A TME foi semelhante em repouso (VPE: 1,41 ± 0,55 VDF/s; IC: 1,39 ± 0,55 VDF/s; P > 0,05) e aumentou na intensidade do LA similarmente em ambos os grupos (VPE: 2,28 ± 0,55 VDF/s; IC: 2,52 ± 1,07 VDF/s; P < 0,0125). Conclusão. Pacientes submetidos a ventriculectomia parcial esquerda apresentam uma o limiar anaeróbio (LA) resposta anormal da função sistólica do ventrículo esquerdo ao exercício na intensidade do LA e uma resposta cronotrópica diminuida ao exercício máximo. Essas respostas anormais podem contribuir para a limitada capacidade ao exercício destes pacientes, a despeito da melhora na função ventricular sistólica em repouso. / Background. Patients with heart failure who have undergone partial left ventriculectomy improve resting left ventricular systolic function, but maintain limited functional capacity. Objective. In order to better understand the mechanisms associated with this limitation, we studied the systolic and diastolic left ventricular function at rest and during submaximal exercise in patients with previous partial left ventriculectomy and in patients with heart failure who had not been operated, matched for maximal and submaximal exercise capacity. Methods: Nine patients with heart failure who were previously submitted to partial left ventriculectomy (PLV) were compared with a group of 9 patients with heart failure who had not been operated. All patients performed a cardiopulmonary exercise testing with measurement of peak oxygen uptake (VO2 peak) and anaerobic threshold (AT). In a second evaluation, radionuclide left ventriculography was performed to analyze ejection fraction (EF) and peak filling rate (PFR) at rest and during exercise at the intensity corresponding to the AT. Results: Groups presented similar exercise capacity evaluated by VO2peak (PLV: [mean ± SD] 13.1 ± 3.3 mL/Kg.min; HF: 14.1 ± 3.6 mL/Kg.min; P > 0.05) and AT (PLV: 7.9 ± 1.3 mL/Kg.min; HF: 8.5 ± 1.6 mL/Kg.min; P > 0.05). Maximal heart rate was higher in the HF group when compared to the PLV group (PLV: 119 ± 20 bpm; HF: 149 ± 21 bpm; P < 0.05). EF at rest was higher in the PLV group (PLV: 40 ± 12 %; HF: 32 ± 9 %; P < 0.0125), however EF increased from rest to AT only in the HF group (PLV: 44 ± 17 %; HF: 39 ± 11 %; P < 0.0125). PFR was similar at rest (PLV: 1.41 ± 0.55 EDV/sec; HF: 1.39 ± 0.55 EDV/sec; P > 0.05) and increased in both groups at the AT intensity (PLV: 2.28 ± 0.55 EDV/sec; HF: 2.52 ± 1.07 EDV/sec; P < 0,0125). Conclusion: Patients who had partial left ventriculectomy present an abnormal response of left ventricular systolic function to exercise at the AT intensity and an impaired chronotropic response to maximal exercise. These abnormal responses may contribute to the limited exercise capacity of these patients, despite the improvement in resting left ventricular systolic function.

Page generated in 0.0341 seconds