The Role of P Wave from Surface Electrocardiography for the Prediction of Atrial Fibrillation after Coronary Artery Bypass Graft Surgery

BACKGROUND AND OBJECTIVES: Atrial fibrillation (AF) is a common arrhythmia that develops after coronary artery bypass graft surgery (CABG), and contributes to the morbidity and prolonged length of hospital day associated with the procedure. The purpose of this study was to determine predictors of AF after CABG.

SUBJECTS AND METHODS: One hundred and twelve (112) patients (mean age 59±10, male 64, female 48), who underwent isolated CABG at one institution, were enrolled. The patients' clinical characteristics, medications, electrocardiogram (ECG), echocardiogram and coronary angiogram were reviewed retrospectively. We measured the P wave duration and dispersion, and the PR interval from 12-lead surface ECG in each patient. Documentation of AF after the CABG was obtained from ECG monitoring in the coronary care unit and those taken after the CABG. Logistic regression analysis was performed, and the discriminatory values of the parameters compared by receiver operating characteristic (ROC) curves.

RESULTS: AF developed in thirty-three patients (29.5%) after the CABG. Multivariable predictors were dichotomized on the basis of their variable distribution. A maximal P wave duration ≥110 msec (p<0.01, sensitivity 88%, specificity 79%) and an age ≥58 years (p=0.023, sensitivity 94%, specificity 54%) were considered significant predictors of AF after CABG.

CONCLUSION: This study has demonstrated that AF after CABG can be predicted preoperatively from a prolonged maximal P wave duration on preoperative ECG and a patient's old age.