Article
Pathology of complete atrioventricular block in chronic Chagas’ myocarditis
Registro en:
ANDRADE, Z. A.; ANDRADE, S. G.; SADIGURSKY, M. Pathology of complete atrioventricular block in chronic Chagas’ myocarditis. Revista da Sociedade Brasileira de Medicina Tropical, v. 21, n. 1, p. 7-13, 1988.
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Autor
Andrade, Zilton de Araújo
Andrade, Sonia Gumes
Sadigursky, Moysés
Resumen
Sclero-atrophy, fibrosis, vascular ectasia, phlebosclerosis and mild non-specific
chronic inflammatory changes were observed in variable location and proportion
involving the atrioventricular conducting tissue o f the heart in five human cases o f
chronic Chagas’ myocarditis associated with complete atrioventricular block. One case
presented complete destruction o f the A- V conduction system. In three cases the lesions
were disseminated all along the conducting tissue but did not cause anywhere a complete
disruption in the continuity o f the system. The distal portion o f the bundle branches were
the most damaged sector o f the system, exceptfor the fasciculi o f the posterior division o f
the left bundle branch which were relatively preserved. One case exhibited bilateral
sclero-atrophy o f the bundle branches as the main change; and another showed early and
mild fibrocalcific damage o f the penetrating portion o f the His bundle. The A -V node
appeared as the least involved part o f the conducting system in the cases studied.
Demonstration o f the lesions in this series o f cases seems important because: a) it
reveals that complete atrioventriculr block in chronic Chagas’ disease results from
disseminated lesions and not from fo ca l disruptive change as has been commonly
observed in cases o f other etiologies; b) it shows that chronic inflammation can produce
at the end variable and widespread vascular, degenerative andfibrotic alterations within
the conducting tissue o f the heart, which may lead to its total destruction.