Background: Atrial systolic dysfunction in patients with coronary artery disease might influence the development of atrial fibrillation after coronary artery bypass grafting (CABG). Tissue Doppler imaging of the mitral annulus during atrial systole has proved to quantify, accurately, left atrial contractile function. Therefore, the aim of the present study was to investigate the correlation between preoperative left atrial dysfunction assessed by tissue Doppler and postoperative atrial fibrillation after CABG.
Methods: We studied a total of 96 patients (mean age 67 +/- 6 years; range, 55 to 81) undergoing CABG who were preoperatively in sinus rhythm. All patients underwent a preoperative transthoracic echocardiography with tissue Doppler evaluation. Until the day of discharge, all patients were monitored with continuous electrocardiographic telemetry.
Results: There were no hospital deaths. Postoperative atrial fibrillation was recorded in 24 of 96 patients (25%). Patients with postoperative atrial fibrillation were significantly older (70 +/- 6 vs 65 +/- 8 years; p = 0.006), had a preoperative larger left atrium diameter (38 +/- 5 vs 36 +/- 4 mm; p = 0.045), a larger left atrium area (13.2 +/- 3.4 vs 11.5 +/- 2.3 cm2; p = 0.007), and a lower peak atrial systolic mitral annular tissue Doppler velocity (10 +/- 3 vs 13 +/- 5 cm/second; p = 0.01). Stepwise logistic regression analysis showed that age 70 years or greater (p = 0.02; odds ratio [OR] 2.0), preoperative medication with beta-blockers (p = 0.04; OR 0.7), left atrium area 13 cm2 or greater (p = 0.02; OR 2.5), and peak atrial systolic mitral annular tissue Doppler velocity 9 cm/second or less (p = 0.03; OR 1.8) were independently related with the incidence of postoperative atrial fibrillation.
Conclusions: Tissue Doppler is useful for assessing preoperative atrial dysfunction and predicting atrial fibrillation after CABG. Further studies are needed to confirm this finding.