Cardiac troponin I (cTnl), troponin T (cTnT), and creatine kinase-MB (CKMB mass) are specific markers of myocardial injury and are, at present, widely used to detect perioperative myocardial damage during coronary artery bypass graft (CABG) surgery. They are also of some help to compare different types and routes of delivery of cardioplegia.However, cTnT and CKMB are expressed in injured striated muscles as well, which limits their specificity. The cardiac isoform of troponin I is highly specific and allows accurate detection of myocardial damage. Therefore, cTnl dosage might help evaluate myocardial injury after CABG. The usefulness of cTnl dosages after CABG has been examined in very few studies and to our knowledge, no report compared cTnl with cTnT and CKMB in the same patients in this setting. canada viagra
The aim of this study was to compare cTnl, cTnT, and CKMB mass in patients with and without new Q wave on the surface ECG after CABG surgery.
Materials and Methods
Eighty-two patients were included in this study. Their mean (±SD) age was 63± 10 years. Patients were scheduled for elective CABG surgery. They were excluded if they had a myocardial infarction or unstable angina in the previous 2 months. The ethics committee gave approval and informed consent was obtained from every patient. Myocardial protection was achieved by using a modified St. Thomas solution that was superfused directly through the coronary ostia until cardiac arrest was obtained and then reinjected every 20 min during aortic cross clamping. Standard cardiopulmonary bypass techniques with moderate hypothermia were used.
All patients underwent a 12-lead surface ECG preoperatively, 1 h, and 24 h postoperatively, and before hospital discharge. ECGs were assessed by an experienced cardiologist unaware of any clinical and biological information. Diagnostic criteria for “new postoperative Q wave” were new Q waves of at least 0.03 s duration or broadening of preexisting Q waves or new QS deflection in at least two leads.