Electrocardiographic changes in experimental chronic murine Chagas' disease

Area of Science:

• Veterinary Cardiology
• Infectious Diseases
• Parasitology

Background:

• Chagas' disease, caused by Trypanosoma cruzi (T. cruzi), can lead to significant cardiac lesions.
• Electrocardiography (ECG) is a crucial diagnostic tool for assessing cardiac function.
• Murine models are frequently used to study infectious diseases and their effects on the cardiovascular system.

Purpose of the Study:

• To evaluate the incidence and types of electrocardiographic alterations in different mouse strains infected with various T. cruzi strains.
• To determine the suitability of the murine model for studying T. cruzi-induced cardiac pathology.

Main Methods:

• Electrocardiographic studies were conducted on AKR, A/J inbred mice, and Swiss outbred mice.
• Mice were chronically infected with T. cruzi strains classified as Type I, II, and III.
• Incidence and types of ECG alterations were recorded and analyzed across different mouse and T. cruzi strain combinations.

Main Results:

• High incidence of ECG alterations observed in AKR mice (80-87%) and A/J mice (26-100%) depending on T. cruzi strain.
• Swiss mice showed ECG alterations in 53.5% (Type II) and 71.4% (Type III) of infections.
• Common alterations included first-degree AV block, intraventricular conduction abnormalities, sinus tachycardia, and bradycardia, with variations based on host-parasite interactions.

Conclusions:

• The type of T. cruzi strain and the mouse strain significantly influence the occurrence and pattern of ECG alterations.
• Specific T. cruzi strains (Type I and III) induced more frequent alterations in A/J mice, while Type III was more prevalent in Swiss mice.
• The murine model is a valuable tool for investigating the electrocardiographic manifestations of cardiac lesions in Chagas' disease.