ABSTRACT
PURPOSE: To study the functional cardiac component of the indeterminate form of experimental Chagas' disease in dogs. METHODS: Four dogs chronically infected with Trypanosoma cruzi and eight normal controls were used. They were submitted to several invasive procedures, either in the presence of complete autonomic block or not, to test for disturbances in the origin and conduction of electric stimuli and the function of cardiac muscle. Histological examination of the heart and its conduction systems was performed in all animals. RESULTS: Mild to moderate focal myocarditis was found in infected dogs, often involving the conduction system of the heart. Sections of the heart from control dogs were histologically normal. Functional data on excitability, intra and interatrial conduction time and sinus node recovering time were essentially similar for both infected and control animals. CONCLUSION: Focal myocarditis, the hallmark of the indeterminate form of Chagas' disease, did not alter the normal parameters of cardiac function, as seen after investigation with sensitive invasive techniques. It is probable that subjects considered as belonging to the indeterminate form of Chagas' disease, but presenting mild alterations at sensitive exploratory tests, may have more severe lesions than that usually described or may be already in the early progressive cardiac form of the disease.
Subject(s)
Animals , Male , Female , Dogs , Mice , Heart Conduction System , Chagas Cardiomyopathy/pathology , Sinoatrial Node , Chagas Cardiomyopathy/chemically inducedABSTRACT
A protese de Omni Science apresenta caracteristicas basicas que lhe dao melhor perfil hemodinamico que as proteses metalicas anteriormente disponiveis. Apresentamos nossa experiencia inicial em 93 casos consecutivos com 96 proteses instaladas num periodo de 31 meses. A mortalidade intra hospitalar foi de 4% nos casos eletivos, sendo maior em cirurgias aorticas com procedimentos associados ou quando realizada de emergencia em casos "in extremis". Em 9 pacientes, no inicio da experiencia, tivemos trombose de protese mitral necessitando reoperacao, com 1 obito; todos os pacientes estao anticoagulados e nao tivemos nenhum caso de embolismo ate o presente. Os resultados clinicos ate o momento, embora seja uma experiencia inicial, sao bastante promissores. A Ommi Science e portanto uma nova alternativa de valvula tipo fluxo central apresentando entretanto caracteristicas proprias que exigem atencao redobrada em sua colocacao, especialmente em posicao mitral
Subject(s)
Humans , Male , Female , Child , Adolescent , Adult , Middle Aged , Heart Valve ProsthesisABSTRACT
Foi realizada cineradioscopia com intensificador de imagem em 19 pacientes portadores de protese de Omni Science, valvula dotada de disco radiopaco que permite facil visibilizacao na radioscopia. Para determinar a sensibilidade e a especificidade do metodo foram estudados 16 pacientes assintomaticos e 3 com suspeita clinica de trombose de protese. Nos assintomaticos, visibilizou-se o disco em todos.Nos outros nao foi visto o disco em 2 casos e, no terceiro, a excursao estava bastante prejudicada. Conclui-se que a radioscopia e um importante auxiliar nao invasivo na avaliacao deste tipo de protese metalica