A miocardiopatia chagásica constitui uma doença prevalente e de alta morbimortalidade no Brasil. Embora seu agente causador, o Trypanosoma cruzi, já tenha sido identificado, os mecanismos fisiopatológicos e a predileção do acometimento por determinados segmentos do miocárdio ainda não foram totalmente esclarecidos. Dentre os mecanismos envolvidos nos distúrbios da microcirculação, inclui-se a hipótese na qual o acometimento preferencial das regiões apical e posterolateral do VE deva-se à presença de áreas de fluxo arterial fronteiriço (\"watershed\") entre as artérias que irrigam as paredes do VE, locais estes com maior predisposição a sofrer processo de isquemia. Ainda que plausível, esta hipótese ainda não foi testada frente a razoável variabilidade da distribuição dos vasos arteriais coronários, o que implica em variações na presença ou não de regiões de \"watershed\" em cada paciente. Objetivo: Estudar a correlação topográfica entre as regiões de \"watershed\" com as alterações da mobilidade ventricular e defeitos de perfusão miocárdica no ventrículo esquerdo. Casuística e Métodos: Realizamos um estudo descritivo com análise de 63 pacientes portadores de cardiopatia chagásica crônica que possuíam cineangiocoronariografia sem lesões obstrutivas significativas e fração de ejeção igual ou superior a 40%. Utilizando a cineangiocoronariografia definimos as regiões passíveis de \"watershed\" baseando-nos na distribuição anatômica das artérias coronárias, tendo como critérios a dominância, a extensão e os limites das artérias coronárias direita e esquerda na irrigação das paredes do VE. Em seguida verificamos se as alterações de mobilidade parietal na ventriculografia e/ou os defeitos de perfusão segmentar na cintilografia de perfusão miocárdica coincidiam com estas regiões. Utilizamos Teste Exato de Fischer para a análise estatística dos resultados. Resultados: Na ventriculografia por contraste as frequências dealterações de mobilidade para as paredes apical, inferior e posterolateral nos pacientes na presença e ausência de respectiva região de WS correspondente foram: 76,2% vs 68,3%, 46,3% vs 38,1% e 54,6% vs 42,9%. Os valores de p obtidos foram respectivamente 0,51; 0,59 e 0,69. Considerando todas as regiões onde o WS estava presente 55,6% apresentavam alteração da mobilidade, em compensação 56,5% das regiões onde o WS estava ausente também apresentavam alteração da mobilidade, com o valor de p = 1,0. Na cintilografia de perfusão miocárdica as frequências de defeitos de captação para os segmentos apicais, inferiores médio e apical, laterais e inferior basal na presença e ausência de respectiva região de WS correspondente foram: 41,2% vs 57,1%, 67,8% vs 47,2%, 50% vs 66,6% e 33,1% vs 50%. Os valores de p obtidos foram respectivamente 0,36; 0,21; 1,0 e 1,0. Considerando todas as regiões onde o WS estava presente 53,3% apresentavam defeitos de captação, em compensação 52,2% das regiões onde o WS estava ausente também apresentavam defeitos de captação com o valor de p = 1,0. Conclusão: No estudo apresentado não se comprovou que as alterações da mobilidade parietal ou os defeitos de perfusão nos segmentos do ventrículo esquerdo ocorram nas regiões de \"watershed\". Portanto nossos resultados não apoiam a hipótese de que as regiões de \"watershed\" contribua para o mecanismo de lesão miocárdica na cardiopatia chagásica crônica. / Chagasic cardiomyopathy is a prevalent disease with high morbidity and mortality in Brazil. Although its causative agent, Trypanosoma cruzi, has already been identified, pathophysiological mechanisms and the predilection for involvement of certain segments of the myocardium have not yet been fully elucidated. Among the mechanisms involved in microcirculation disorders, the hypothesis is included in which the preferential affection of the apical and posterolateral regions of the LV is due to the presence of areas of bordered arterial flow (\"watershed\") between the arteries that irrigate the walls of the LV, these places are more likely to undergo ischemia. Although plausible, this hypothesis has not yet been tested against the reasonable variability of coronary artery distribution, which implies variations in the presence or absence of watershed regions in each patient. Objective: To study the topographic correlation between watershed regions with the ventricular mobility abnormalities and myocardial perfusion defects in the left ventricle. Methods: We conducted a descriptive study with 63 patients with chronic chagasic cardiopathy who had coronary angiography without significant obstructive lesions and ejection fraction equal to or greater than 40%. Using the cineangiocoronariography, we defined watershed regions based on the anatomical distribution of the coronary arteries, taking as criteria the dominance, extension and limits of the right and left coronary arteries in the irrigation of the LV walls. Next, we verified whether the parietal mobility abnormalities in ventriculography and / or segmental perfusion defects in myocardial perfusion scintigraphy coincided with these regions. We used Fisher\'s exact test for the statistical analysis of the results. Results: In contrast ventriculography, the frequencies of mobility abnormalities for the apical, inferior and posterolateral walls in patients in the presence and absence of a corresponding WS region were: 76.2% vs 68.3%, 46.3% vs 38 , 1% and 54.6% vs 42.9%. The values of p obtained were respectively 0.51; 0.59 and 0.69. Considering all the regions where WS was present, 55.6% had mobility alterations; in contrast, 56.5% of the regions where WS was absent alsopresented mobility alterations with p value = 1.0. In myocardial perfusion scintigraphy, the frequencies of uptake defects for the apical, lower mid and apical, lateral and lower basal segments in the presence and absence of the corresponding WS region were: 41.2% vs 57.1%, 67.8 % vs 47.2%, 50% vs 66.6% and 33.1% vs 50%. The values of p obtained were respectively 0.36; 0.21; 1.0 and 1.0. Considering all the regions where the WS was present, 53.3% presented perfusional defects, in compensation 52.2% of the regions where WS was absent also had perfusional defects with p value = 1.0. Conclusion: In the presented study it was not verified that the alterations of the parietal mobility or the perfusion defects in the segments of the left ventricle occur in the watershed regions. Therefore our results do not support the hypothesis that watershed regions contribute to the mechanism of myocardial injury in chronic Chagas\' heart disease.

Thesis (M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (ℓ. 82-87)

Thesis (M.S.)--Oregon State University, 1988. / Typescript (photocopy). Includes bibliographical references (leaves 129-133). Also available on the World Wide Web.

Thesis (M.S.)--Oregon State University, 1988. / Typescript (photocopy). Includes bibliographical references (leaves 106-117). Also available on the World Wide Web.

Thesis (M.S.)--Ohio University, November, 2004. / Includes bibliographical references (p. 69-73)

Thesis (Ph. D.)--Oregon State University, 2000. / Typescript (photocopy). Includes bibliographical references (leaves 119-125). Also available online.

Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains xvii, 180 p.; also includes graphics (some col.). Includes bibliographical references (p. 156-171). Available online via OhioLINK's ETD Center

Thesis (M.S.)--Ohio University, November, 2004. / Title from PDF t.p. Includes bibliographical references (p. 69-73)

A miocardiopatia chagásica constitui uma doença prevalente e de alta morbimortalidade no Brasil. Embora seu agente causador, o Trypanosoma cruzi, já tenha sido identificado, os mecanismos fisiopatológicos e a predileção do acometimento por determinados segmentos do miocárdio ainda não foram totalmente esclarecidos. Dentre os mecanismos envolvidos nos distúrbios da microcirculação, inclui-se a hipótese na qual o acometimento preferencial das regiões apical e posterolateral do VE deva-se à presença de áreas de fluxo arterial fronteiriço (\"watershed\") entre as artérias que irrigam as paredes do VE, locais estes com maior predisposição a sofrer processo de isquemia. Ainda que plausível, esta hipótese ainda não foi testada frente a razoável variabilidade da distribuição dos vasos arteriais coronários, o que implica em variações na presença ou não de regiões de \"watershed\" em cada paciente. Objetivo: Estudar a correlação topográfica entre as regiões de \"watershed\" com as alterações da mobilidade ventricular e defeitos de perfusão miocárdica no ventrículo esquerdo. Casuística e Métodos: Realizamos um estudo descritivo com análise de 63 pacientes portadores de cardiopatia chagásica crônica que possuíam cineangiocoronariografia sem lesões obstrutivas significativas e fração de ejeção igual ou superior a 40%. Utilizando a cineangiocoronariografia definimos as regiões passíveis de \"watershed\" baseando-nos na distribuição anatômica das artérias coronárias, tendo como critérios a dominância, a extensão e os limites das artérias coronárias direita e esquerda na irrigação das paredes do VE. Em seguida verificamos se as alterações de mobilidade parietal na ventriculografia e/ou os defeitos de perfusão segmentar na cintilografia de perfusão miocárdica coincidiam com estas regiões. Utilizamos Teste Exato de Fischer para a análise estatística dos resultados. Resultados: Na ventriculografia por contraste as frequências dealterações de mobilidade para as paredes apical, inferior e posterolateral nos pacientes na presença e ausência de respectiva região de WS correspondente foram: 76,2% vs 68,3%, 46,3% vs 38,1% e 54,6% vs 42,9%. Os valores de p obtidos foram respectivamente 0,51; 0,59 e 0,69. Considerando todas as regiões onde o WS estava presente 55,6% apresentavam alteração da mobilidade, em compensação 56,5% das regiões onde o WS estava ausente também apresentavam alteração da mobilidade, com o valor de p = 1,0. Na cintilografia de perfusão miocárdica as frequências de defeitos de captação para os segmentos apicais, inferiores médio e apical, laterais e inferior basal na presença e ausência de respectiva região de WS correspondente foram: 41,2% vs 57,1%, 67,8% vs 47,2%, 50% vs 66,6% e 33,1% vs 50%. Os valores de p obtidos foram respectivamente 0,36; 0,21; 1,0 e 1,0. Considerando todas as regiões onde o WS estava presente 53,3% apresentavam defeitos de captação, em compensação 52,2% das regiões onde o WS estava ausente também apresentavam defeitos de captação com o valor de p = 1,0. Conclusão: No estudo apresentado não se comprovou que as alterações da mobilidade parietal ou os defeitos de perfusão nos segmentos do ventrículo esquerdo ocorram nas regiões de \"watershed\". Portanto nossos resultados não apoiam a hipótese de que as regiões de \"watershed\" contribua para o mecanismo de lesão miocárdica na cardiopatia chagásica crônica. / Chagasic cardiomyopathy is a prevalent disease with high morbidity and mortality in Brazil. Although its causative agent, Trypanosoma cruzi, has already been identified, pathophysiological mechanisms and the predilection for involvement of certain segments of the myocardium have not yet been fully elucidated. Among the mechanisms involved in microcirculation disorders, the hypothesis is included in which the preferential affection of the apical and posterolateral regions of the LV is due to the presence of areas of bordered arterial flow (\"watershed\") between the arteries that irrigate the walls of the LV, these places are more likely to undergo ischemia. Although plausible, this hypothesis has not yet been tested against the reasonable variability of coronary artery distribution, which implies variations in the presence or absence of watershed regions in each patient. Objective: To study the topographic correlation between watershed regions with the ventricular mobility abnormalities and myocardial perfusion defects in the left ventricle. Methods: We conducted a descriptive study with 63 patients with chronic chagasic cardiopathy who had coronary angiography without significant obstructive lesions and ejection fraction equal to or greater than 40%. Using the cineangiocoronariography, we defined watershed regions based on the anatomical distribution of the coronary arteries, taking as criteria the dominance, extension and limits of the right and left coronary arteries in the irrigation of the LV walls. Next, we verified whether the parietal mobility abnormalities in ventriculography and / or segmental perfusion defects in myocardial perfusion scintigraphy coincided with these regions. We used Fisher\'s exact test for the statistical analysis of the results. Results: In contrast ventriculography, the frequencies of mobility abnormalities for the apical, inferior and posterolateral walls in patients in the presence and absence of a corresponding WS region were: 76.2% vs 68.3%, 46.3% vs 38 , 1% and 54.6% vs 42.9%. The values of p obtained were respectively 0.51; 0.59 and 0.69. Considering all the regions where WS was present, 55.6% had mobility alterations; in contrast, 56.5% of the regions where WS was absent alsopresented mobility alterations with p value = 1.0. In myocardial perfusion scintigraphy, the frequencies of uptake defects for the apical, lower mid and apical, lateral and lower basal segments in the presence and absence of the corresponding WS region were: 41.2% vs 57.1%, 67.8 % vs 47.2%, 50% vs 66.6% and 33.1% vs 50%. The values of p obtained were respectively 0.36; 0.21; 1.0 and 1.0. Considering all the regions where the WS was present, 53.3% presented perfusional defects, in compensation 52.2% of the regions where WS was absent also had perfusional defects with p value = 1.0. Conclusion: In the presented study it was not verified that the alterations of the parietal mobility or the perfusion defects in the segments of the left ventricle occur in the watershed regions. Therefore our results do not support the hypothesis that watershed regions contribute to the mechanism of myocardial injury in chronic Chagas\' heart disease.

A geographically-based framework for landuse suitability assessment and land capability classification in Ibulao watershed, Philippines was developed and used in this study. Landuse suitability assessment was based primarily on soil erosion, the results of which were compared with the outcome of suitability assessments based on two land classification systems in the Philippines. The Ibulao watershed was subdivided into 10-ha cells, and each cell was independently evaluated with the aid of a geographic information system called MAP. The soil erosion rates for each cell were estimated using the MUSLE. The surface runoff and peak runoff rates were simulated using an infiltration-kinematic routing model, an event-based stochastic rainfall duration model, and the CREAMS model. The land capability classification was based on erosion index representing the inherent soil erodibility of a cell computed on the basis of runoff erosivity factor, soil erodibility factor, and the slope length-gradient factor. The results of capability classification were used to identify the different alternative uses of any cell in the watershed. The framework described in this study for landuse suitability assessment and land capability classification illustrated potentials for applications to the management and allocation of land resources in the Philippines. An erosion-based landuse assessment and land capability classification appears to be a better alternative to a slope-based system as far as the following are concerned: (1) identification of landuses which would not jeopardize the long term productivity and stability of an area; (2) a more accurate and meaningful land capability description and classification; and (3) making more lands available for various alternative uses by using criteria such as soil erosion which can easily be manipulated.