Background: Myocardial dysfunction has been documented in septic infants, but minimal information is available in neonatal foals.
Objectives: To evaluate if hospitalized neonatal foals have evidence of myocardial dysfunction when compared to healthy foals. Animals: Seventy-three foals < 14 days of age.
Methods: Prospective cohort study. Foals were classified as septic (n=22), sick non septic (SNS; n=19), and healthy controls (n=32). Serum cardiac troponin I (cTnI) concentrations at admission and 72 hours later, echocardiographic parameters measured within 24 hours of admission, and 72-hour Holter ECG tracings, were compared between groups using a Kruskal-Wallis test and two way mixed-effects model statistical analysis.
Results: Healthy foals had elevated cTnI concentrations over the first 5 days of life. Levels were significantly higher at 12 (median 453.1pg/ml, IQR 143.3-976.1pg/ml, p= 0.006) and 24 (median 397.6pg/ml, IQR 147.4-665.3 pg/ml, p=0.02) hours compared to time 0 (birth). No differences in cTnI were found between groups (p>0.05). Median cTnI was significantly higher (p < 0.05) at the first sampling time point in all foals (healthy: 209.5pg/ml IQR [123.2-809.7pg/ml]), (SNS: 156.8pg/ml [68.85-380pg/ml]), (Septic: 307.3pg/ml [142.5-647.6pg/ml]) compared to 72 hours later (healthy: 99.3pg/ml [67.6-160pg/ml]), (SNS: 40.25pg/ml [26.2-81.11pg/ml]), (Septic: 56.84pg/ml [27-99.8pg/ml]). Several septic foals trended towards a higher frequency of ventricular events. No differences in echocardiographic or electrocardiographic indices were found between groups (p>0.05). Conclusions and Clinical Importance: Elevated cTnI concentrations should be interpreted with caution in newborn foals. Evidence of myocardial dysfunction was not identified in this hospitalised population of neonatal foals. Further investigation of arrhythmia prevalence in septic foals is warranted.
