Cardiac damage in dogs infected with T brucei; clinical and electrocardiographic features

Abstract

ABSTRACTIntravenous infection of dogs with Trypanosoma brucei resulted in an acute disease syndrome, characterised by fever, intense parasitaemia, severe anaemia and rapid weight loss. During the course of infection, evidence of severe cardiac abnormalities developed. Tachycardia and tachypnoea occurred soon after detection of parasitaemia, around day 6, progressing to severe bradycardia and dyspnoea in terminal stages of the disease in week 4. Murmurs of mitral and tricuspid incompetence were heard from day 12 by auscultation of the thoracic cavity. Electrocardiography revealed abnormalities in generation and conduction of electrical impulses, including sinus arrest and atrioventricular blocks, and accumulation of pericardial effusion in terminal stages. Effective treatment with the trypanocidal drug suramin resulted in rapid improvement of one of the dogs. When treatment was unsuccessful, however, chronic myocardial damage developed, with intramyocardial conduction defects, including S‐T segment and T wave changes, and ventricular escape beats. These abnormalities were similar to those reported for human African trypanosomiasis.