[Clinical, electrocardiographic and angiographic evaluation of natural reservoirs of Chagas' disease in the Republic of Panama].

The authors studied two groups of natural animal reservoirs for Trypanosoma cruzi: a wild one, the common rat Rattus rattus and the house dog, Canis canis. Thirty one naturally infected rats were evaluated with a technique developed by the authors which allows the recording of the ECG and the performance of a ventricular angiogram without altering the functional capacity of the animal. Forty four dogs were followed clinically for a period of twenty years to study the development of the cardiac lesion seen in the chronic phase of the disease. The authors demonstrate the epidemiologic importance of the dog as a reservoir and the ease with which the infection can be acquired from rats, which live in the same habitat with human patients. The most common lesions in both groups were ventricular and atrial arrhythmias and second degree AV block; and, in the dogs, also death due to refractory cardiac failure, such as is seen in the human patient. Right bundle branch block and dilatation of the right cardiac chambers was the rule in both groups. The authors discuss the pathogenesis of the ECG in the rat and its anatomical basis. They propose the possibility of establishing and standardizing this techniques in the laboratories that study rats or other species.