BACKGROUND: Heart rate variability might predict arrhythmias after coronary artery bypass grafting. METHODS: Off-line processing of 10-min electrocardiogram recordings of consecutive patients provided R-R intervals for time domain, frequency domain, Poincare, and point correlation analyses and subsequent association with postoperative atrial fibrillation by stepwise multivariate logistic regression. RESULTS: Of 88 patients who met entry criteria, 13 developed atrial fibrillation. Peak point correlation dimension (odds ratio 3.985/unit, P = 0.0096) and age (odds ratio 1.144/yr, P = 0.0019) were independently associated with atrial fibrillation (c-statistic = 0.839). CONCLUSIONS: Further study should confirm the ability of peak point correlation dimension to predict atrial fibrillation after coronary artery surgery with cardiopulmonary bypass.