[Clinico-pathological correlation in the indeterminate form of experimental Chagas' disease in dogs].
OBJECTIVE
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.


CONCLUSIONS
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.
Scalabrini
A
A
Instituto do Coração do Hospital das Clínicas-FMUSP, Hospital Português, Salvador.
Cardoso
A
A
Andrade
S G
SG
Andrade
Z A
ZA
D000818:Animals; D002598:Chagas Cardiomyopathy / Q000139:chemically induced / Q000473:pathology*; D004285:Dogs; D005260:Female; D006329:Heart Conduction System; D008297:Male; D051379:Mice; D012849:Sinoatrial Node
Correlação clínico-patológica na forma indeterminada da doença de Chagas experimental do cão.