Recovery of linear and nonlinear heart rate dynamics after coronary artery bypass grafting surgery

Area of Science:

• Cardiology
• Autonomic Nervous System Function
• Surgical Outcomes

Background:

• Conventional coronary artery bypass grafting (C-CABG) and off-pump CABG (OPCAB) surgery can lead to varying degrees of cardiac autonomic (CA) imbalance.
• Previous research by our group demonstrated exercise-based inpatient programs improve heart rate variability (HRV) in C-CABG patients.
• The impact of cardiac rehabilitation (CR) on HRV post-OPCAB remains unstudied.

Purpose of the Study:

• To compare the influence of C-CABG and OPCAB on HRV patterns.
• To evaluate the effect of a CR program on HRV in patients undergoing these surgical techniques.
• To assess the recovery of CA function post-surgery and CR.

Main Methods:

• HRV indices were measured pre- and post-CR in 15 C-CABG and 13 OPCAB patients.
• A short-term (5-day) supervised CR program involving early mobilization and progressive exercises was implemented.
• Exercise progression ranged from active-assistive movements on post-operative day 1 to stair climbing by post-operative day 5.

Main Results:

• Both C-CABG and OPCAB groups experienced a reduction in HRV post-surgery.
• The CR program led to improvements in HRV indices for both patient groups upon discharge.
• The OPCAB group exhibited higher HRV values at discharge, suggesting superior recovery of CA function.

Conclusions:

• Inpatient CR programs enhance CA function recovery in post-CABG patients.
• OPCAB surgery, combined with inpatient CR, appears to promote greater improvement in CA function compared to C-CABG.