Impact of Physical Exercise on Release of Cardiac Troponins: Evaluation in Healthy and Cardiopathic Dogs

The purpose of this study was to evaluate the impact of physical exercise on the release of cardiac troponins (cTn). Sixteen dogs were evaluated: 8 clinically healthy (group A) and 8 (group B) with valve disease in the asymptomatic stage (class I, New York Heart Association). All dogs, after a complete cardiac evaluation, were forced to exercise on a motorized treadmill at three different speeds: 1.8 km/h (low speed), 3.6 km/h (medium speed), and 5.4 km/h (high speed) lasting 6 min. Each test was performed on different days. Plasma samples were refrigerated at −20°. cTnI and cTnT were measured just before the running test, after a recovery period of 20 min, and then 2, 4, and 6 h later. cTnI concentrations increased in group A only at the highest speed, while cTnT did not change. These results suggest that exercise may induce myocardial suffering.