The effect of CRT on incidence of AF development in patients with severe HF was explored by comparing 36 patients with conventional indication for the CRT to 36 HF patients without CRT, matched for age, sex and LV systolic function (Publication 5). After a follow up of 3 years, the annual incidence of AF in the CRT group was 2.8%, which was significantly lower than the control group (10.2%). Moreover, the echocardiographic benefit by CRT was compared between these 36 patients with SR and 15 patients with persistent AF. The results showed that the echocardiographic response was similar between the two groups. These findings suggested that CRT may have the potential to reduce AF burden in patients with severe HF and that patients with persistent AF may also benefit from CRT. / The objective of the study (Publication 1) was to assess the feasibility of using non-contact LV mapping to delineate the LV endocardial activation pattern in 7 HF patients in NYHA class III, with low LVEF and wide QRS complex (>120ms). Non-contact mapping was safely performed and there were two endocardial conduction patterns identified, namely homogenous (Type I) and conduction block (Type II). The second part of the study (Publication 2) was to determine the implication of these two distinct activation patterns to echocardiographic and clinical response to CRT. 23 patients in NYHA class III, with LVEF <35% and QRS duration >120ms were recruited in this study. 15 patients had Type II pattern and 8 Type I. The QRS duration between the two types of conduction patterns were comparable. Patients with Type II pattern had a more favourable echocardiographic and clinical response to CRT than those with Type I. It was concluded that, despite the similar QRS duration between the two types of LV endocardial activation patterns, patients with Type II pattern had a more favourable response to CRT. / The significance of baseline renal function in CRT was assessed in 85 consecutive patients with conventional indication for the CRT (Publication 7). There was no significant relationship between baseline renal function and significant LV reverse remodeling after CRT, suggesting baseline renal insufficiency probably would not affect the response to CRT. (Abstract shortened by UMI.) / This study (Publication 3) was to determine the effect of CRT in patients with narrow QRS complex and evidence of mechanical dyssynchrony as determined by TDI. 51 patients in NYHA class III or IV, with LV ejection fraction <35%, and QRS duration <120ms were recruited for the CRT. The effect of the device therapy on LV systolic function in this cohort was compared to 51 patients who fulfilled the current criteria with wide QRS complex. CRT significantly improved the LV systolic function, NYHA class and exercise capacity in those with narrow complex to a similar extent in those with wide complex. With co-existing mechanical dyssynchrony determined by TDI, patients in both narrow and wide QRS complex groups showed more favourable response to CRT than those without significant mechanical dyssynchrony. This confirmed that QRS was a poor marker of mechanical dyssynchrony and the current selection criteria are probably not adequate to include more potential responders to the therapy. / This study (Publication 4) was to determine the role of optimal medical therapy in CRT recipients before implantation. The echocardiographic and clinical effect of CRT in 30 patients without the optimal combination of ACEi or ARB and beta-blockers was compared to 30 patients matched for age, sex, NYHA class and HF etiology. Patients with optimal medical therapy had significantly better echocardiographic and clinical response to CRT. The results confirmed that optimal medical therapy is necessary to achieve maximal response by CRT. / This study (Publication 6) was to determine if patients with moderate LV systolic function and wide QRS complex would benefit from the CRT. Significant improvement in LV systolic function was observed in 15 patients with LVEF between 35 and 45%, NYHA class III and QRS duration >120ms after CRT, suggesting that presence of LV systolic dysfunction and cardiac dyssynchrony may be the major determining factors for favourable CRT response. Therefore, patients with less advanced HF may also benefit from the CRT. / "May 2007." / Adviser: Yu Cheuk Man. / Source: Dissertation Abstracts International, Volume: 69-08, Section: B, page: 4657. / Thesis (M.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 133-151). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / School code: 1307.

SUmmaries in Afrikaans and English / Text in Afrikaans / Die oogmerk van hierdie verhandeling is om te wys op die tekstuele en visuele kontraste in Georgi con 11.1 - 108. Ten aanvang word 'n bree vergelyking getreftussen Georgicon I en II om sodoende die funksie asook die effek van Boek 2 in die viertal gedigte te bepaal. Vir 'n meer indringende ontleding word Boek 2, asook die relevante verse, skematies verdeel en alhoewel die panoramiese effek versteur word, kan die problematiek van hierdie gedig alleenlik s0 noukeuriger opgelos word. Daar word getoon dat Boek 2 in drie afdelings verdeel is met 'n laus-tema wat telkens as hoogtepunt dien vir elk van die dele. Ook die oorkoepelende tema van variatio-labor en die wisselwerking daarvan kan duideliker waargeneem word. Verse I - I 08 is didakties van aard en eenvoudige patrone word saamgestel uit alledaagse objekte en idees. Vergilius slaag daarin om vergelykings af te dwing en om kontras te bewerkstellig deur die skep van imagines. Hierdie beelde kom duideliker na vore deur 'n baie noukeurige analise van die teks en s6 word vorm, lyn, kleur en tekstuur beklemtoon en gekontrasteer. W anneer die fokus verskuif vanaf die natuur na die mens, word daar gewys op die kontras in verse 3 5 - 46 tussen die landbouers en die politieke magsfiguur van Maecenas. Die onderliggende felix I fortuna/us tema word s6 beklemtoon. Die problematiek van didaktisisme word aangespreek deur die effek van die kontrastering van parallelle passasies aan te toon. As Leitmotiv word telkens gewys op die tekstuele en visuele kontraste in die digter se keuse en rangskikking van 'n ryke verskeidenheid van borne - met spesifieke verwysing na hulle aard, voorkoms, herkoms en funksie. / The aim of this dissertation is to indicate the textual and visual contrasts in Georgi con TI.l - 108. In a broad comparison between Georgica I and II the function and the effect ofBook 2 within the framework of the four poems is determined. With a view to a more penetrating analysis, Book 2 as a whole and specifically lines 1 - 108 will be dealt with schematically. Although this puts the panoramic effect at risk, it is the only way in which the complexities of this poem can be successfully resolved. Book 2 is shown to have a tripartite structure, with a taustheme as the climax of each of the three divisions. The over-arching theme of reciprocating variatio- labor also comes to light more clearly. Lines I - I 08 are of a didactic nature, and simple patterns are shaped out of everyday objects and ideas. By creating imagines Vergil manages to enforce comparisons and to bring about contrasts. A meticulous analysis of the text highlights these images more clearly and in this manner the poet accentuates colour, form, line and texture. When the focus shifts from nature to man, the contrast between the farmers and the politically powerful Maecenas in lines 3 5 - 46 is brought to the fore to emphasize the underlying theme of felix I fortunatus. The problem of didacticism is addressed by focusing on the effect of the contrasts between parallel passages. The textual and visual contrasts in the poet's choice and marshalling of a rich variety of trees, with a particular reference to their nature, occurrence, provenance and function, serve as Leitmotif for the dissertation as a whole. / Classics and Modern European Languages / M.A. (Latyn)

Introdução: A formação de atelectasia durante a indução anestésica pode ser um dos fatores responsáveis pela ocorrência de complicações pulmonares pós-operatórias (CPP). A aplicação de pressão positiva expiratória ao final da expiração (PEEP), uso criterioso de altas frações inspiradas de oxigênio e a utilização de manobras de recrutamento alveolar no período intra-operatório são recursos utilizados para a prevenção de atelectasia em procedimentos anestésicos. O objetivo deste estudo foi avaliar o modelo de ventilação mecânica adotado em procedimentos anestésicos de longa duração e suas correlações com as complicações pulmonares pós-operatórias. Métodos: Foram avaliadas em estudo observacional as cirurgias com mais de cinco horas de duração. No início do procedimento anestésico, na sala de cirurgia e após o seu término, na unidade de terapia intensiva, os parâmetros ventilatórios utilizados foram anotados e correlacionados com os achados das radiografias torácicas e saturação periférica de oxigênio (SpO2) em ar ambiente. Resultados: Cento e vinte e um pacientes foram observados. O tempo total de anestesia 499,4 ± 159,8 minutos. O volume corrente (VC) determinado no período intraoperatório foi 8,09 ± 2,15 mL/kg e a PEEP utilizada de 3,05 ± 2,31 cmH2O. Houve diferença para a mediana da SpO2 em ar ambiente (96% [95-97] vs 95% [92-96], p <0,001) comparando os períodos pré e pós-operatório. A freqüência de pacientes que apresentaram atelectasia nas radiografias de tórax do período pós-operatório (38,8%) foi significantemente maior que a do período pré-operatório (0%), x2=32,259. Não foi encontrado correlação entre os achados e o tempo de anestesia (p=0,708); a PEEP intra-operatória (p=0,296); tempo de permanência com suporte ventilatório mecânico no pósoperatório (p = 0,146) e tabagismo (p = 0,563). Conclusões: No período intra-operatório o PEEP utilizado em procedimentos de longa duração é baixo. Ocorre queda na SpO2 e aumento na incidência de atelectasia no período pós-operatório em comparação com o pré-operatório. São necessários outros estudos para melhor avaliação dos fatores responsáveis / Introduction: The formation of the atelectasis during the induction of the anesthesia can be one of the factors involved in the occurrence of postoperative pulmonary complications (PPCs). The application of the positive end-expiratory pressure (PEEP), low inpiratory concentrations of oxygen and the alveolar recruitment maneuvers perform in the intraoperative period are approaches used in the prevention of atelectasis in the anesthesia procedures. The objective of this study was to evaluate, in prospective observational study, the pattern of mechanical ventilatory assistence during longer anesthesia procedures and its correlations with the PPCs. Methods: The surgeries procedures longer than five hours have been evaluated in observational study. At the beginning of the anesthesia procedure, in the operatory room and after its terminus, in the intensive care unit, the mechanical ventilation parameters were determined and correlated with the findings in the chest x-rays and peripheral oxygen saturation (SpO2) in room air. Results: One hundred twenty one patients have been observed. The total time of anesthesia was 499,4 ± 159,8 minutes. The tidal volume (VT) in the intraoperative period was 8,09 ± 2,15 mL/kg and the PEEP used was 3,05 ± 2,31 cmH2O. There was a difference for the median of the SpO2 in room air (96% [95-97] vs 95% [92-96], p <0,001) comparing the pre and postoperative periods. The frequency of patients who had presented atelectasis in the chest x-rays of the postoperative period (38,8%) was significantly higher than the preoperative period (0%), x2=32,259. No correlation was found among these findings and the anesthesia time (p=0,708); the intraoperative PEEP used (p=0,296); time with mechanical ventilatory support in the postoperative period (p = 0,146) and smoking habits (p = 0,563). Conclusions: In the intraoperative period, the PEEP is low in longer procedures. The SpO2 decreases and the incidence of the atelectasis increases in the postoperative period, when compared with the preoperative one. Other researches are required for better evaluation of the factors related for the development of the PPCs

Introdução: A formação de atelectasia durante a indução anestésica pode ser um dos fatores responsáveis pela ocorrência de complicações pulmonares pós-operatórias (CPP). A aplicação de pressão positiva expiratória ao final da expiração (PEEP), uso criterioso de altas frações inspiradas de oxigênio e a utilização de manobras de recrutamento alveolar no período intra-operatório são recursos utilizados para a prevenção de atelectasia em procedimentos anestésicos. O objetivo deste estudo foi avaliar o modelo de ventilação mecânica adotado em procedimentos anestésicos de longa duração e suas correlações com as complicações pulmonares pós-operatórias. Métodos: Foram avaliadas em estudo observacional as cirurgias com mais de cinco horas de duração. No início do procedimento anestésico, na sala de cirurgia e após o seu término, na unidade de terapia intensiva, os parâmetros ventilatórios utilizados foram anotados e correlacionados com os achados das radiografias torácicas e saturação periférica de oxigênio (SpO2) em ar ambiente. Resultados: Cento e vinte e um pacientes foram observados. O tempo total de anestesia 499,4 ± 159,8 minutos. O volume corrente (VC) determinado no período intraoperatório foi 8,09 ± 2,15 mL/kg e a PEEP utilizada de 3,05 ± 2,31 cmH2O. Houve diferença para a mediana da SpO2 em ar ambiente (96% [95-97] vs 95% [92-96], p <0,001) comparando os períodos pré e pós-operatório. A freqüência de pacientes que apresentaram atelectasia nas radiografias de tórax do período pós-operatório (38,8%) foi significantemente maior que a do período pré-operatório (0%), x2=32,259. Não foi encontrado correlação entre os achados e o tempo de anestesia (p=0,708); a PEEP intra-operatória (p=0,296); tempo de permanência com suporte ventilatório mecânico no pósoperatório (p = 0,146) e tabagismo (p = 0,563). Conclusões: No período intra-operatório o PEEP utilizado em procedimentos de longa duração é baixo. Ocorre queda na SpO2 e aumento na incidência de atelectasia no período pós-operatório em comparação com o pré-operatório. São necessários outros estudos para melhor avaliação dos fatores responsáveis / Introduction: The formation of the atelectasis during the induction of the anesthesia can be one of the factors involved in the occurrence of postoperative pulmonary complications (PPCs). The application of the positive end-expiratory pressure (PEEP), low inpiratory concentrations of oxygen and the alveolar recruitment maneuvers perform in the intraoperative period are approaches used in the prevention of atelectasis in the anesthesia procedures. The objective of this study was to evaluate, in prospective observational study, the pattern of mechanical ventilatory assistence during longer anesthesia procedures and its correlations with the PPCs. Methods: The surgeries procedures longer than five hours have been evaluated in observational study. At the beginning of the anesthesia procedure, in the operatory room and after its terminus, in the intensive care unit, the mechanical ventilation parameters were determined and correlated with the findings in the chest x-rays and peripheral oxygen saturation (SpO2) in room air. Results: One hundred twenty one patients have been observed. The total time of anesthesia was 499,4 ± 159,8 minutes. The tidal volume (VT) in the intraoperative period was 8,09 ± 2,15 mL/kg and the PEEP used was 3,05 ± 2,31 cmH2O. There was a difference for the median of the SpO2 in room air (96% [95-97] vs 95% [92-96], p <0,001) comparing the pre and postoperative periods. The frequency of patients who had presented atelectasis in the chest x-rays of the postoperative period (38,8%) was significantly higher than the preoperative period (0%), x2=32,259. No correlation was found among these findings and the anesthesia time (p=0,708); the intraoperative PEEP used (p=0,296); time with mechanical ventilatory support in the postoperative period (p = 0,146) and smoking habits (p = 0,563). Conclusions: In the intraoperative period, the PEEP is low in longer procedures. The SpO2 decreases and the incidence of the atelectasis increases in the postoperative period, when compared with the preoperative one. Other researches are required for better evaluation of the factors related for the development of the PPCs

SUmmaries in Afrikaans and English / Text in Afrikaans / Die oogmerk van hierdie verhandeling is om te wys op die tekstuele en visuele kontraste in Georgi con 11.1 - 108. Ten aanvang word 'n bree vergelyking getreftussen Georgicon I en II om sodoende die funksie asook die effek van Boek 2 in die viertal gedigte te bepaal. Vir 'n meer indringende ontleding word Boek 2, asook die relevante verse, skematies verdeel en alhoewel die panoramiese effek versteur word, kan die problematiek van hierdie gedig alleenlik s0 noukeuriger opgelos word. Daar word getoon dat Boek 2 in drie afdelings verdeel is met 'n laus-tema wat telkens as hoogtepunt dien vir elk van die dele. Ook die oorkoepelende tema van variatio-labor en die wisselwerking daarvan kan duideliker waargeneem word. Verse I - I 08 is didakties van aard en eenvoudige patrone word saamgestel uit alledaagse objekte en idees. Vergilius slaag daarin om vergelykings af te dwing en om kontras te bewerkstellig deur die skep van imagines. Hierdie beelde kom duideliker na vore deur 'n baie noukeurige analise van die teks en s6 word vorm, lyn, kleur en tekstuur beklemtoon en gekontrasteer. W anneer die fokus verskuif vanaf die natuur na die mens, word daar gewys op die kontras in verse 3 5 - 46 tussen die landbouers en die politieke magsfiguur van Maecenas. Die onderliggende felix I fortuna/us tema word s6 beklemtoon. Die problematiek van didaktisisme word aangespreek deur die effek van die kontrastering van parallelle passasies aan te toon. As Leitmotiv word telkens gewys op die tekstuele en visuele kontraste in die digter se keuse en rangskikking van 'n ryke verskeidenheid van borne - met spesifieke verwysing na hulle aard, voorkoms, herkoms en funksie. / The aim of this dissertation is to indicate the textual and visual contrasts in Georgi con TI.l - 108. In a broad comparison between Georgica I and II the function and the effect ofBook 2 within the framework of the four poems is determined. With a view to a more penetrating analysis, Book 2 as a whole and specifically lines 1 - 108 will be dealt with schematically. Although this puts the panoramic effect at risk, it is the only way in which the complexities of this poem can be successfully resolved. Book 2 is shown to have a tripartite structure, with a taustheme as the climax of each of the three divisions. The over-arching theme of reciprocating variatio- labor also comes to light more clearly. Lines I - I 08 are of a didactic nature, and simple patterns are shaped out of everyday objects and ideas. By creating imagines Vergil manages to enforce comparisons and to bring about contrasts. A meticulous analysis of the text highlights these images more clearly and in this manner the poet accentuates colour, form, line and texture. When the focus shifts from nature to man, the contrast between the farmers and the politically powerful Maecenas in lines 3 5 - 46 is brought to the fore to emphasize the underlying theme of felix I fortunatus. The problem of didacticism is addressed by focusing on the effect of the contrasts between parallel passages. The textual and visual contrasts in the poet's choice and marshalling of a rich variety of trees, with a particular reference to their nature, occurrence, provenance and function, serve as Leitmotif for the dissertation as a whole. / Classics and Modern European Languages / M.A. (Latyn)

O momento ideal para a extubação de crianças graves é ainda difícil de ser avaliado. A razão entre espaço morto e volume corrente (Vd/Vt), como valor preditiva de extubação bem sucedida, já foi testada em adultos e crianças. O objetivo deste trabalho foi avaliar a eficácia do Vd/Vt, como preditivo do sucesso da extubação, em crianças de uma UTI pediátrica geral. Após aplicação dos critérios de inclusão e exclusão, testou-se o Vd/Vt em 86 pacientes extubados num período de 16 meses. Nos estudos estatísticos o índice Vd/Vt médio não discriminou os grupos de falha e sucesso na extubação nas análises uni e multivariada. O valor do índice, com corte em 0,65, foi limitado na sensibilidade e especificidade e mediano na razão de verossimilhança. O estudo sugere que o índice Vd/Vt, pode ser considerado como complementar aos dados de avaliação clínica no momento da extubação. / The ideal moment for extubation of critically ill children is still difficult to determine. The dead-space : tidal volume ratio (Vd/Vt) has been tested as predictor of extubation failure in adults and children. The purpose of this study was to evaluate the efficacy of the Vd/Vt as a predictor of the success of extubation in children admitted to a pediatric intensive care unit. After the inclusion and exclusion criteria, 86 patients were studied during 16 months. The statistical study revealed that the mean Vd/Vt was not able to discriminate between failure and success of extubation in the multivariate analysis. The utility of the Vd/Vt was limited, in terms of sensibility and specificity, using a cutoff of 0,65, but was medially satisfactory in the likelihood ratio. This study suggests that the Vd/Vt can only be considered as complementary to the routine clinical evaluation prior to extubation.

O momento ideal para a extubação de crianças graves é ainda difícil de ser avaliado. A razão entre espaço morto e volume corrente (Vd/Vt), como valor preditiva de extubação bem sucedida, já foi testada em adultos e crianças. O objetivo deste trabalho foi avaliar a eficácia do Vd/Vt, como preditivo do sucesso da extubação, em crianças de uma UTI pediátrica geral. Após aplicação dos critérios de inclusão e exclusão, testou-se o Vd/Vt em 86 pacientes extubados num período de 16 meses. Nos estudos estatísticos o índice Vd/Vt médio não discriminou os grupos de falha e sucesso na extubação nas análises uni e multivariada. O valor do índice, com corte em 0,65, foi limitado na sensibilidade e especificidade e mediano na razão de verossimilhança. O estudo sugere que o índice Vd/Vt, pode ser considerado como complementar aos dados de avaliação clínica no momento da extubação. / The ideal moment for extubation of critically ill children is still difficult to determine. The dead-space : tidal volume ratio (Vd/Vt) has been tested as predictor of extubation failure in adults and children. The purpose of this study was to evaluate the efficacy of the Vd/Vt as a predictor of the success of extubation in children admitted to a pediatric intensive care unit. After the inclusion and exclusion criteria, 86 patients were studied during 16 months. The statistical study revealed that the mean Vd/Vt was not able to discriminate between failure and success of extubation in the multivariate analysis. The utility of the Vd/Vt was limited, in terms of sensibility and specificity, using a cutoff of 0,65, but was medially satisfactory in the likelihood ratio. This study suggests that the Vd/Vt can only be considered as complementary to the routine clinical evaluation prior to extubation.