Abstract

 

Objective: This study is designed to investigate the effects of coronary collateral circulation on preoperative and postoperative QT dispersion in patients undergoing CABG operation.

Method: Fifty-two patients undergoing isolated coronary artery bypass were enrolled in this study. These patients were classified according to the presence or absence of collateral vessels into 3 groups; presence of collateral vessels from right coronary system to left coronary system (Group 1, n=13), from left coronary system to right coronary (Group 2, n=15), and absence of collaterals (control group, n=24). In all patients, 12-lead electrocardiography was recorded to calculate QT dispersion preoperatively and on the first, 5th, and 30th postoperative day.

Results: Comparisons of the groups’ preoperative characteristics identified a significantly higher prevalence of hypertension in Group 1 and Group 2 than that in control group. Mean preoperative QTd was significantly prolonged in Group 2 than that in control group and in Group 1. There was a significant reduction in QTd from before surgery to all postoperative measurements in control group and in Group 1. However, mean QTd in Group 2 did not showed a significant decrease after surgery in     Group 2.

Conclusion: The study showed that coronary artery bypass grafting may reduce QTd. However, presence of collateral circulation in patients undergoing coronary artery surgery did not affect preoperative and postoperative QTd.

Key Word: Collateral circulation, Coronary disease, Coronary artery bypass, QT dispersion.