Changes in Heart Rate Variability in patients under local anesthesia

Area of Science:

• Cardiology
• Autonomic Nervous System Research
• Anesthesiology

Background:

• Spectral analysis of Heart Rate Variability (HRV) is crucial for assessing cardiovascular autonomic control.
• Anesthetic agents are known to influence HRV parameters, necessitating precise analytical methods.
• Ectopic beats can interfere with spectral measurements, requiring robust signal processing techniques.

Purpose of the Study:

• To develop and apply a systematic HRV analysis methodology.
• To investigate and mitigate the impact of ectopic beats on spectral HRV measurements.
• To evaluate the effect of brachial plexus block anesthesia on HRV parameters.

Main Methods:

• A novel detrending method using Wavelet Packets was developed to remove trends from HRV signals without altering LF and HF components.
• Parametric Autoregressive (AR) modeling was employed for spectral analysis of HRV.
• Electrocardiogram (ECG) signals from 14 patients undergoing brachial plexus block were analyzed.

Main Results:

• The developed Wavelet Packet detrending method effectively removed trends while preserving LF and HF components.
• Analysis revealed a decrease in the LF/HF ratio within one hour post-brachial plexus block in approximately 80% of patients.
• This suggests a significant impact of local anesthesia on cardiac autonomic regulation.

Conclusions:

• The Wavelet Packet detrending method offers a reliable approach for HRV analysis in the presence of trends and ectopic beats.
• Brachial plexus block anesthesia demonstrably alters cardiovascular autonomic control, as indicated by HRV changes.
• This study provides valuable insights into the physiological effects of local anesthesia on the autonomic nervous system.