RESUMO
OBJECTIVES: The purpose of this study was to investigate the changes in myocardial function in patients after coronary artery bypass graft (CABG) surgery using longitudinal and circumferential strain on speckle-tracking imaging. METHODS: A total of 145 patients who successfully underwent CABG surgery with a left ventricular ejection fraction (LVEF) of 50% or greater were enrolled in this study. Patients were classified into 4 groups based on age: group 1 (33-59 years), group 2 (60-64 years), group 3 (65-69 years), and group 4 (70-79 years). Routine echocardiography and longitudinal and circumferential strain measurements on speckle-tracking imaging were performed 1 week before and 1, 3, and 6 months after the CABG. RESULTS: In all groups, longitudinal strain increased significantly at 3 and 6 months after CABG therapy compared to baseline (P < .05). A significant increase in circumferential strain was found 1 month after the CABG in groups 1, 2, and 3, and a continuous increase in the parameter was observed in all groups 3 months after therapy (P < .05). However, the LVEF, left ventricular end-diastolic dimension, and stroke volume measured by routine echocardiography were not significantly changed after successful CABG treatment in all groups during 6 months of follow-up. CONCLUSIONS: Based on the results of our study in all age groups, speckle-tracking imaging parameters are more effective than the LVEF, left ventricular end-diastolic dimension, and stroke volume for monitoring improvement in myocardial function after CABG surgery.