Experimental Chagas disease in dogs. Morphologic and electrocardiographic relations in the acute phase of the infection
Andrade, Z.A.; Andrade, S.G.; Sadigursky, M.; Lima, J.A.
Arquivos Brasileiros de Cardiologia 35(6): 485-490
1980
ISSN/ISBN: 0066-782X PMID: 7259577 Document Number: 156159
Acute myocarditis in young dogs, experimentally infected with Trypanosoma cruzi, showed that lesions progress from the atria toward the ventricles. Fully developed myocarditis was characterized by predominance of lesions in the right atrium, in the right half of the ventricular septum and in the free wall of the right ventricle. The conduction system was also involved by inflammation which seemed to propagate centrifugally from the A-V [atrio-ventricular] node toward the periphery. Electrocardiography revealed bradycardia and/or tachycardia, wandering pacemaker, deformities of the P wave, atrial fibrillation and nodal rhythm reflecting progressive atrial involvement. Cardiac block appeared with severe inflammation and necrosis of the main His bundle and its branches in terminal infections. Progressive indications of myocardial damage appeared with alterations of ST segment and T waves and in the low voltage QRS. The electrocardiogram is a good monitor of the peculiar distribution and progression of the lesions in acute myocarditis caused by T. cruzi.