Heart Rate Variability and Its Role in Predicting Atrial Fibrillation in Patients Undergoing Coronary Artery Bypass Graft

Abstract

Ngo Van Thanh,1 Nguyen Sinh Hien,1 Pham Nguyen Son,2 Dinh Cong Pho,3 Pham Truong Son3 1Hanoi Heart Hospital, Hanoi, Vietnam; 2 108 Military Central Hospital, Hanoi, Vietnam; 3Department of Cardiology, Heart Institute, 108 Military Central Hospital, Hanoi, VietnamCorrespondence: Pham Truong Son, Email [email protected]: An association between heart rate variability (HRV) and cardiac events in certain diseases has been demonstrated. However, the association with new-onset atrial fibrillation (AF) after coronary artery bypass grafting (CABG) is still controversial. This study aimed to investigate the association between HRV and new-onset AF in patients undergoing CABG during a 6-month follow-up.Methods: This prospective study included 119 consecutive patients who underwent off-pump CABG. All patients were assessed using 24-hour Holter recordings 2 days before CABG and 1 week, 3 months, and 6 months postoperatively. HRV was analyzed, and AF was detected from its recordings.Main results: In patients undergoing CABG, NYHA III increased the AF rate 7 days postoperatively, and advanced age and diabetes were associated with AF 6 months postoperatively. A reduction in time-domain measurements before surgery was significantly associated with a higher risk of developing AF seven days postoperatively; no association between preoperative HRV and AF was found at six months. Reduced preoperative HRV (SDNN (standard deviation of all normal-to-normal intervals [) < 50 ms) was an independent predictor of AF at 3 (AUC = 0.65) and 6 months (AUC = 0.62) following surgery.Conclusion: A reduction in the time domain measurements before CABG was associated with a higher risk of new-onset AF at 7 days postoperatively but not at 6 months. An SDNN < 50 ms was a weak independent predictor of a higher incidence of AF at 3 and 6 months post-surgery.Keywords: heart rate variability, coronary artery bypass graft, atrial fibrillation, standard deviation of all normal-to-normal intervals

Keywords

• heart rate variability
• coronary artery bypass graft
• atrial fibrillation
• standard deviation of all normal-to-normal intervals.