Relation between left ventricular function and oxidative stress in patients undergoing bypass surgery

Objective - To determine whether preoperative left ventricular ejection fraction (LVEF) is related to the degree of myocardial oxidative stress during bypass surgery in man. Design - Observation study. Setting - Tertiary care centre. Patients and interventions -31 patients (LVEF range was 20% to 68%) undergoing elective coronary bypass surgery with blood cardioplegic reperfusion were studied. Arterial and coronary sinus blood was collected before aortic cross clamping (T1) and at 0 (T1), 15 (T2), and 30 (T3) minutes after unclamping. Transmural left ventricular biopsies were also obtained from 15 patients at T0 and at T1. Main outcome measures - Glutathione and adenine nucleotides were measured in myocardial biopsies, while coronary sinus-artery differences for glutathione, nucleotides, and products of lipids peroxidation were calculated from blood specimens. Creatine kinase (myocardial band; CK-MB) was measured in plasma at four and 12 hours after operation. Results - Myocardial glutathione and adenine nucleotides were correlated (p