Concentration of cardiac troponin I in a horse with a ruptured aortic regurgitation jet lesion and ventricular tachycardia.

The research paper discusses a case of an 18-year-old horse that had high levels of cardiac troponin I (cTnI), due to a ruptured aortic regurgitation defect and resulting ventricular tachycardia, suggesting that cTnI could be a useful marker for assessing heart disease in horses.

Case Summary

• The research began when an 18-year-old Thoroughbred gelding was brought in for examination due to sudden onset of ventricular tachycardia and symptoms of colic. Three years prior, the horse had been noticed to have a diastolic decrescendo murmur, a sign indicative of aortic regurgitation. However, despite this condition, the horse was able to continue its performance and compete effectively.
• On examination via cardiac ultrasonography, a defect was discovered in the interventricular septum, located under the aortic root. Blood tests also indicated elevated levels of cardiac troponin I (cTnI), higher than what would be observed in horses with normal health.
• Despite efforts to save the horse, the recurrent development of tachyarrhythmia during its hospital stay led to a decision to euthanize the animal.
• Post-mortem examination, known as a necropsy, revealed a ruptured endocardial jet lesion below the aortic valve leading to the formation of a cleft into the interventricular septum.

Implications of Findings

• This research report is particularly notable for its observations on increased serum cTnI concentrations in a horse with myocardial disease (heart muscle disease). This could suggest that cTnI concentrations could be a significant indicator in evaluating horses suspecting of having myocardial disease.
• The researchers believe that the assessment of cardiac troponin concentrations could prove to be a handy tool in diagnosing and understanding the severity of myocardial diseases in horses.