Short periods of regional ischaemia and reperfusion provoke release of troponin I from the human hearts.

Whether cardiac troponin I (cTnI) is better at detecting minor myocardial damage than other biochemical markers, is still controversial. In this report we monitored the response of the human heart to short periods of regional ischaemia and reperfusion (3 min each) by measuring cTnI release in the coronary sinus and the radial artery of patients undergoing coronary revascularisation surgery on beating heart without cardiopulmonary bypass. Our data show for the first time that the human heart releases significant amounts of cTnI in response to minor cardiac insults. However because of dilution, this release cannot be easily detected outside the coronary circulation. Therefore, an improved sensitivity of the assays used to measure cTnI may provide an ideal tool for assessing minor myocardial damage.