Quantitative analysis of cardiac lesions in chronic canine chagasic cardiomyopathy

Revista do Instituto de Medicina Tropical de São Paulo

Marcelo Vidigal Caliari²  Raquel Do Pilar Machado¹  Marta De Lana¹  Rosângela Aparecida França CajÁ²  Cláudia Martins Carneiro¹  Maria Teresinha Bahia¹  César Augusto Bueno Dos Santos¹  Gustavo Albergaria MagalhÃes²  Ivan Barbosa Machado Sampaio¹  Washington Luiz Tafuri² 

[1] ,Universidade Federal de Minas Gerais Instituto de Ciências Biológicas Departamento de Patologia GeralBelo Horizonte MG ,Brasil

关键词: Trypanosoma cruzi;    Chagasic cardiomyopathy;    Myocarditis;    Fibrosis;    Congestive cardiac insufficiency;   

DOI  :  10.1590/S0036-46652002000500008

来源: SciELO

【 摘 要 】

Lesions observed in chronic chagasic cardiopathy frequently produce electrocardiographic alterations and affect cardiac function. Through a computerized morphometrical analysis we quantified the areas occupied by cardiac muscle, connective and adipose tissues in the right atrium of dogs experimentally infected with Trypanosoma cruzi. All of the infected dogs showed chronic myocarditis with variable reduction levels of cardiac muscle, fibrosis and adipose tissue replacement. In the atrial myocardium of dogs infected with Be78 and Be62 cardiac muscle represented 34 and 50%, fibrosis 28 and 32% and adipose tissue 38 and 18%, respectively. The fibrosis observed was both diffuse and focal and mostly intrafascicular, either partially or completely interrupting the path of muscle bundles. Such histological alterations probably contributed to the appearance of electrocardiographic disturbances verified in 10 out 11 dogs which are also common in human chronic chagasic cardiopathy. Fibrosis was the most important microscopic occurrence found since it produces rearrangements of collagen fibers in relation to myocardiocytes which causes changes in anatomical physiognomy and mechanical behavior of the myocardium. These abnormalities can contribute to the appearance of cardiac malfunction, arrythmias and congestive cardiac insufficiency as observed in two of the analyzed dogs. Strain Be78 caused destruction of atrial cardiac muscle higher than that induced by strain Be62.

【 授权许可】

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