Heart rate variability measures poorly predict atrial fibrillation after off-pump coronary artery bypass grafting

Study ObjectiveTo investigate associations of heart rate variability (HRV) measurements with postoperative atrial fibrillation (AF) in patients undergoing off-pump coronary surgery.DesignProspective, observational, exploratory study.SettingLarge university-affiliated community medical center.Patients50 patients undergoing off-pump coronary artery bypass grafting (CABG).InterventionsPreoperative recording of electrocardiograms (ECGs) with subsequent off-line HRV analysis. Monitored ECG telemetry for 5 days after operation.MeasurementsFrequency and time domain analyses, and additional non-linear HRV determinations. Multivariate regression analysis of predictors of postoperative AF.Main ResultsAF occurred in 23 (46%) patients. Only the low to high-frequency ratio was associated with AF (2.35 ± 1.8 v. 4.57 ± 5.0 for patients without AF, P < 0.05).ConclusionsThe off-pump approach does not protect against AF, and nonlinear HRV analyses provide little value in predicting AF after off-pump CABG.