(C41) Cardiac Abnormalities Using a Simplified Diagnostic Evaluation in Dogs at Risk for Trypanosoma Cruzi Infection

Abstract: Background- Trypanosoma cruzi causes cardiac abnormalities in a subset of infected dogs. Diagnosis is challenging with limited access to advanced diagnostics.Objective- To describe association of abnormalities and serostatus using a simplified diagnostic evaluation. Animals- Forty-six, asymptomatic dogs at risk for T. cruzi infection. Methods- Prospective, cross-sectional study consisting of two antibody tests for T. cruzi (indirect fluorescent antibody, TVMDL; Chagas STAT-PAK validated for humans, Chembio Diagnostics), blood PCR, cardiac troponin I, 30-second IDEXX CardioPet ECG (with review of automated measurements), and focused echocardiogram (right sided study with 7 variables). Dogs were categorized as seropositive (SP), seronegative (SN), or discordant (SD) based on antibody results. Associations of ordinal data were explored with chi-square tests.Results- Dogs were SP (19), SN (17), and SD (10) with 9 PCR positive across groups (7 SP, 1 SN, 1 SD). Serum troponin was above reference range in 6/46 (4 SP, 1 SN, 1 SD). ECG abnormalities were documented in 10/46 (8 SP, 0 SN, 2 SD), including conduction abnormalities (prolonged P, PR, QRS durations, second degree atrioventricular block, splintered QRS complex) and ventricular ectopy. Echocardiographic abnormalities were documented in 23/46 (9 SP, 10 SN, 4 SD) predominately related to left atrial and ventricular enlargement and complicated by degenerative valve disease. Conduction abnormalities and ventricular ectopy were associated with positive serostatus.Conclusions and clinical importance- Echocardiographic abnormalities were complicated by concurrent heart disease and did not distinguish between serostatus. ECG is a simple test to perform with abnormalities more common in SP dogs.