New Onset Atrial Fibrillation after Coronary Artery Bypasses Grafting; an Evaluation of Mechanical Left Atrial Function

This study attempted to identify the role of combined conventional and novel echocardiographic techniques in evaluation of left atrial (LA) function to predict the postoperative AF (POAF). In this cross-sectional study, subjects with sinus rhythm who were candidates for CABG were enrolled. Preoperative LA function was evaluated by conventional echocardiography and 2-dimensional strain imaging based-velocity vector imaging (VVI). VVI-derived systolic peak positive, early and late diastolic strain rate were measured. Using tissue Doppler study, systolic peak velocities (Sm), early diastole (Em), atrial systole (Am) and AEMi were also measured. The patients were observed during their hospital stay. The primary endpoint of the study was postoperative AF lasting > 5minutes. POAF occurred in 12.7% of patients. Age, LA volume index (LAVI), LA area, LA empting fraction (LAeF) and cardiopulmonary bypass time were found to be the independent predictors of POAF. TDI-derived velocities were similar in study groups. LA systolic strain rate (SRs) and early diastolic strain rate were impaired in patients with no significant difference between those who developed POAF and those who did not. Conventional echocardiography could be used as a feasible method for evaluating subclinical atrial dysfunction in patients undergoing CABG and the use of VVI- based 2-dimensional strain imaging may need further studies.