Biochemical Evidence of Myocardial Cell Damage in Heart Failure : A Canine Model of Cardiac Injury

The objective of the present study was to evaluate the diagnostic efficiency of the new cardiac-specific marker troponin T (cTnT) compared with the conventional markers creatine kinase (CK) and lactate dehydrogenase (LDH) in detecting myocardial injury in dogs with clinical signs and symptoms of various forms of cardiac diseases including congestive heart failure (CHF). The results showed that in animals with clinical valvular heart disease (n = 20), clinical cardiac arrhythmias (n = 11) and heartworm infection (n = 10) without clinical heart failure, as well as in dogs with clinical CHF (n = 18), there was no significant difference either in the activity of CK or LDH. Levels of cTnT in dogs with CHF, on the other hand, were much higher than those in the other 3 groups. The majority of the 18 dogs with CHF had detectable levels of cTnT, with 6 of them (33%) showing values exceeding the upper reference limit of 0.10 ng/ml. The overall mean cTnT level in this animal group was 0.204 ng/ml. These results may imply that CHF in dogs is associated with a small release of cardiac troponin T indicative of minor myocardial cell damage