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Published on: March 27, 2018
Investigation of heart rate variability of patients undergoing coronary artery bypass grafting (CABG)
Insights
Coronary artery bypass grafting (CABG) improves autonomic function, as indicated by increased heart rate variability (HRV) high-frequency power and decreased low-frequency power 6 and 30 days post-surgery.
Area of Science:
- Cardiovascular Surgery
- Autonomic Nervous System Function
- Heart Rate Variability Analysis
Background:
- Coronary artery bypass grafting (CABG) is a key intervention for severe coronary artery disease (CAD).
- Heart rate variability (HRV) offers a non-invasive method to assess autonomic function.
- Investigating HRV before and after CABG provides insights into cardiovascular autonomic regulation post-surgery.
Purpose of the Study:
- To non-invasively evaluate HRV in patients undergoing CABG.
- To monitor patient status via HRV on postoperative days 6 and 30.
- To understand CABG's impact on cardiovascular autonomic function and surgical outcomes.
Main Methods:
- A soft-decision wavelet-based spectral analysis technique was employed.
- HRV power spectral density of VLF, LF, and HF bands was measured.
- 24 patients were assessed pre-CABG (G1), 6 days post-CABG (G2), and 30 days post-CABG (G3).
Main Results:
- High-frequency (HF) power increased in 22/24 patients in G2 vs. G1.
- Low-frequency (LF) power decreased in 21/24 patients in G2 vs. G1.
- VLF and LF power sums decreased in all 24 patients in G2 vs. G1, and in 19/24 in G3 vs. G1.
Conclusions:
- Post-CABG, HF power significantly increased by day 6 compared to pre-CABG.
- LF power demonstrated a decrease by day 6 post-CABG.
- At 30 days post-CABG, sustained increases in HF power and decreases in LF power were observed in most patients.
Background:
Myocardial revascularization by coronary artery bypass grafting (CABG) is an effective measure for reducing symptoms and mortality in patients with unstable or severe coronary artery disease (CAD). Autonomic function can be estimated non-invasively using heart rate variability (HRV). HRV of patients undergoing CABG is investigated before and after CABG using a soft-decision wavelet based spectral analysis.
Objective:
The main purpose of this work is to evaluate non-invasively HRV in patients undergoing CABG before operation; and to monitor the status of patients through HRV investigation on day 6 and day 30 after the CABG operation. The study intends to contribute scientific value to understanding the effect of CABG on the cardiovascular autonomic function and surgical outcome.
Methods:
The soft-decision wavelet-based technique is used in this work in order to measure the power spectral density of the three main bands (VLF, LF, and HF) of HRV in 24 patients undergoing CABG operation, before the operation (Group 1: G1), and 6 days after operation (Group 2: G2) and 30 days after operation (Group 3: G3). The data is obtained from Sultan Qaboos University hospital in Oman.
Results:
The HF power increases in 22 out of 24 patients in G2 compared to G1. While the LF power decreases in 21 out of 24 patients in G2 compared to G1. Comparing G3 to G1 the LF power decreases in 20 patients. The sum of the VLF and LF power is reduced in G2 in all 24 subjects compared to G1, and in 19 subjects in G3 compared to G1.
Conclusions:
The power spectral density of the HF shows increase in patients recorded on day 6 after operation compared to patients before the operation. The LF shows a decrease in G2 compared to G1. The results of G3 after 30 days of operation still show an increase of the HF power and a decrease in the LF power in most of the patients compared to their values before operation.
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