Change in Autonomic Nervous System Activity during an Early Mobilization Program for Patients after Coronary Artery Bypass Surgery

Abstract

[Purpose] The purpose of this study was to clarify the variations in autonomic nervous system (ANS) activity using heart rate variability analysis during an early mobilization program on the first and second days after coronary artery bypass grafting surgery. [Participants and Methods] The cohort comprised 15 patients who underwent coronary artery bypass grafting surgery on a standby basis. We examined the fluctuation of ANS activity in the supine position, sitting position, and standing position, before and after cardiac surgery, using frequency analysis of heart rate variability. [Results] Low frequency/high frequency (LF/HF) significantly increased and HF values significantly decreased at rest after cardiac surgery compared to preoperative rest. LF/HF increased and HF values decreased significantly compared to their values at rest after cardiac surgery following the implementation of an early mobilization program in the early postoperative period. However, there was no significant difference in the rate of change of LF/HF and HF values before and after cardiac surgery, when posture was changed from supine to standing. [Conclusion] These results suggest that early mobilization can be performed if the rate of change in ANS activity during postural change is comparable to that before cardiac surgery.