Papel dos pressorreceptores nas alterações cardiorrespiratórias induzidas pelo infarto do miocárdio

• Ano de defesa: 2006
• Autor(a) principal: Mostarda, Cristiano [UNIFESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo (UNIFESP)
• Palavras-chave em Português: Miocárdio; Análise espectral; Barorreflexo; Infarto do miocárdio; Mortalidade; Ecocardiografia
• Link de acesso: http://repositorio.unifesp.br/handle/11600/9903

Changes in baroreflex sensitivity have been implicated in reduction of heart rate variability and increase of death risk after myocardial infarction The objectives of this study was to investigate if the impairment of baroreflex control of circulation induced by MI in sinoaortic denervated (SAD) rats is associated with changes in LF component of HRV and if the abolishment of the baroreflex would be associated with increased mortality after myocardial infarction in rats. The rats were distributed in 4 groups: control(C), myocardial infarction(MI), SAD and denervated infarcted (SAD+MI) groups. MI (90 days) reduced ejection fraction (42%) but induces left ventricle mass increase only in SAD+MI rats. Baroreflex sensitivity was reduced after MI but additionally impaired in MI denervated rats. HRV was lower in SAD+MI than in MI and SAD groups. LF power of HRV was reduced in all experimental groups but was additionally reduced in SAD+MI rats. There was a direct correlation between baroreflex sensitivity and LF power of HRV. LV mass was positively correlated with blood pressure variability. The results of the present study showed that the decrease in baroreflex sensitivity is associated with LF power of HRV reduction and that the degree of impairment of baroreflexes as well as the reduction of LF power of HRV, determines the mortality post MI during a 90 days period.