Left Atrial Strain Assessed by Speckle Tracking Imaging Is Related to New-Onset Atrial Fibrillation After Coronary Artery Bypass Grafting

Background: Left atrial (LA) dysfunction was recently proposed as an important factor in the development of postoperative atrial fibrillation (POAF). LA strain analysis by 2-dimensional (2D) speckle tracking imaging is emerging as a new tool to evaluate LA function. We aimed to evaluate the correlation of LA dysfunction assessed by 2D speckle tracking imaging with the occurrence of POAF after coronary artery bypass grafting (CABG). Methods: In this study, 53 patients (mean age 66 +/- 9 years) undergoing elective isolated CABG were enrolled. Conventional transthoracic echocardiography and 2D speckle tracking strain analysis were performed before surgery. POAF was detected with continuous electrocardiography monitoring throughout hospitalization (mean duration 17 +/- 10 days). Results: POAF occurred in 13 of 53 patients (24%). Patients with POAF were significantly older than patients with normal sinus rhythm after surgery (71 +/- 5 vs 64 +/- 10 years, P = 0.026). Compared with patients with normal sinus rhythm, patients with POAF had a significantly larger LA volume index (32.6 +/- 5.1 vs 27.3 +/- 7.2 mL/m(2), P = 0.018), lower value of LA global strain (25.4 +/- 10.4 vs 36.8 +/- 7.6%, P = 0.001), and strain rate (1.2 +/- 0.6 vs 1.6 +/- 0.8 seconds, P = 0.024). By multivariate logistic regression analysis, only LA global strain (odds ratio, 1.12; 95% confidence interval, 1.00-1.24; P = 0.040) was an independent predictor of POAF after CABG. Conclusions: Preoperative LA global strain measured by 2D speckle tracking strain analysis is associated with the development of POAF after CABG.