The role of surface ECG and transthoracic echocardiography for predicting postoperative atrial fibrillation after coronary artery bypass surgery

OBJECTIVE: To evaluate the roles of surface electrocardiogram (ECG) and transthoracic echocardiography (ECHO) for prediction of atrial fibrillation (AF) after coronary artery bypass grafting (CABG). METHODS: This study was conducted from 2002-2004 at the Cardiovascular Department of Hacettepe University, Ankara, Turkey. Seventy consecutive patients were enrolled in this study that underwent elective CABG. A 12-lead ECG was recorded one day before cardiac surgery and was repeated during the 5 days after CABG. P-wave dispersion (PWD) was defined as the difference between maximum and minimum P-wave duration. Differences in P-wave duration were compared between the pre- and postoperative 12-lead ECG measurements. RESULTS: Postoperative AF developed in 17 (24%) cases of 70 patients. The PWD was found to be significantly higher in patients with AF preoperatively (60+/-19 versus 47+/-13, p=0.003), postoperative first day (56+/-12 versus 44+/-11, p<0.002) and fifth day (51+/-29 versus 41+/-11, p<0.001). Patients with AF were significantly older, the mean age of the AF group was (68+/-7) years and of the sinus rhythm (SR) group was (59+/-10 years) (p<0.001). The AF group had left ventricular systolic dysfunction (56+/-13% versus 56+/-8%, p=0.042, preoperatively; 49+/-8% versus 60+/-10%, p=0.001, postoperatively) and a larger left atrium (46+/-5 versus 39+/-5 mm, p<0.001, preoperatively and 44+/-7 versus 39+/-5 mm, p=0.046, postoperatively) than the SR group. CONCLUSION: This prospective study demonstrated that PWD on surface ECG and additional echocardiographic parameters are simple and reliable indexes to predict the development of AF after CABG.