Characterization of arrhythmias, evaluation of cardiac biomarkers and their association with survival in calves suffering from foot-and-mouth disease

• Published in: Journal of veterinary cardiology 2021-08, Vol.36, p.64-76
• Main Authors: Mahadappa, P., Mahendran, K., Winter, R.L., Umapathi, V., Krishnaswamy, N., Gopalakrishnan, A., Rao, S., Gangaiah, M., Kumar, S., Patel, B.H.M., Gautam, N., Hegde, R., Dechamma, H.J., Sanyal, A.
• Format: Article
• Language: English
• Subjects: Cardiac troponin; Electrocardiography; Foot-and-mouth disease; Prognosis; Purkinje cells
• ISSN: 1760-2734; 1875-0834
• DOI: 10.1016/j.jvc.2021.04.002

Foot-and-mouth disease (FMD) causes mortality in calves due to myocarditis; however, the effects of FMD virus on cardiac arrhythmogenesis and Purkinje cells are unknown. Identifying diagnostic and prognostic markers in FMD-affected calves may be useful in disease management in the endemic countries. A total of 81 FMD-affected calves were prospectively monitored till death or recovery. Foot-and-mouth disease was diagnosed by serology and reverse transcriptase–polymerase chain reaction (RT-PCR). Electrocardiography was recorded and serum cardiac biomarkers were measured. Histopathological examination of the ventricular myocardium was carried out in the calves that died of FMD (n = 33). Apparently healthy calves (n = 15) served as control. Serology and RT-PCR consistently revealed that the FMD was caused by serotype O virus. Arrhythmias occurred in 62 of 81 (76.5%) FMD-affected calves, of which, ventricular premature complexes (VPCs) were the most common type (22%). The combined mortality rate due to ventricular tachycardia, polymorphic VPCs, and atrial fibrillation was 27.6%. Receiver operating characteristic curve analysis revealed that cardiac troponin I (cTnI) concentrations of ≥1.3 ng/mL were diagnostic of myocarditis with a sensitivity and specificity of 90% and 100%, respectively. Similarly, serum cTnI concentrations of