Pattern Changes in the Heart Rate Variability of Patients Undergoing Coronary Artery Bypass Grafting Surgery

Abstract

Introduction. Coronary artery bypass grafting (CABG) with extracorporeal circulation is a key therapy for coronary artery disease (CAD). However, cardiovascular events and cardiac arrhythmias may still occur in these patients following surgery. Many studies have demonstrated a correlation between cardiac arrhythmias and heart rate variability (HRV). This study aimed to establish the temporal change pattern of HRV observed following CABG. Methods. A prospective method was used to study 119 consecutive patients with stable CAD who were assessed using 24-hour Holter recordings 2 days before CABG and 1 week, 3 months, and 6 months after the surgery at Hanoi Heart Hospital from June 2016 to August 2018. Main results: All the time-domain and frequency-domain parameters of HRV decreased precipitately after CABG and were mostly recovered 3 months postoperatively. The percentage of decreased HRV before surgery was 28.6% and 51.8% after 7 days, 19.6% after 3 months, and 12.7% after 6 months. ASDNN and SDNN before and after surgery had the highest rates of change. Conclusion. The early decrease in HRV observed 7 days after CABG may be related to the acute effects of the surgery. The recovery of HRV at 3 months after surgery, regardless of the preoperative state of the patients, implies that the autonomic nervous system (ANS) disorder may be improved at this time. At 6 months after surgery, the autonomic nervous injury was recovered in combination with improvement of reperfusion, resulting in improvement in almost all HRV indices compared with those indices preoperatively.

The impact of preoperative stress on individuals' experience of postoperative complications after undergoing cardiac surgery

“…CABG surgery patients were less nervous preoperatively than valve surgery patients. CABG patients had greater anxiety levels in other trials [18]. Using the conventional analgesia procedure, moderate to severe anxiety patients had greater postoperative pain ratings than mild anxiety patients in the first 24 hours.…”

Heart Rate Variability and Coronary Artery Bypass Grafting: A Systematic Review

“…Published studies of the short-term changes in HRV post-CABG are listed in Table 4 (Ref. [ 18 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ]). In addition, some of these studies recorded HRV changes beyond 6 weeks post-CABG, these results are discussed in the section following this one.…”

“…All studies reported a decrease in traditional HRV parameters immediately after surgery, reaching their lowest value at 3–6 days post-CABG and remaining depressed even 6-weeks follow up after surgery [ 24 , 25 , 26 , 27 , 28 , 29 ]. Thanh et al .…”

“…Thanh et al . [ 27 ] showed that decreased HRV before surgery was present in 28.6% of patients in 51.8% after seven days, 19.6% after three months, and 12.7% after six months. However, in contrast the finding of Bellwon et al .…”

“…It has now been established, as described in the first section of this review, that HRV decreases acutely after CABG [ 24 , 25 , 26 , 27 , 28 , 29 ]. However, the effect on HRV beyond 6-weeks post-CABG is still unclear.…”