Related Experiment Video
Updated: Jun 18, 2026
09:56
Implantation of Combined Telemetric ECG and Blood Pressure Transmitters to Determine Spontaneous Baroreflex Sensitivity in Conscious Mice
Published on: February 14, 2021
Transfer function analysis of baroreflex function in a rabbit model of endotoxic shock
Collin H H Tang1, Gregory S H Chan, Paul M Middleton
1School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, NSW 2052, Australia. hhtang@student.unsw.edu.au
Summary
Endotoxemia impairs baroreflex control of heart rate and reduces cardiac vagal modulation, as shown by decreased coherence and transfer function gain between systolic blood pressure and heart rate variability in rabbits.
Area of Science:
- Cardiovascular Physiology
- Autonomic Nervous System Research
- Sepsis Pathophysiology
Background:
- Sepsis causes significant cardiovascular dysfunction, potentially due to autonomic regulatory disturbances.
- The arterial baroreflex system plays a crucial role in cardiovascular regulation.
Purpose of the Study:
- To investigate the impact of endotoxemia on cardiovascular autonomic regulation and baroreflex function.
- To utilize a rabbit model of endotoxic shock to mimic sepsis-induced cardiovascular changes.
Main Methods:
- A rabbit model of endotoxic shock was established using endotoxin injection.
- Measurements of heart rate variability (RRi) and systolic blood pressure (SBP) were analyzed using spectral and cross-spectral methods.
- Transfer function analysis was employed to assess baroreflex control.
Main Results:
- Endotoxin administration led to increased blood lactate levels, indicating distributive shock.
- Significant decreases in coherence and phase delay between SBP and RRi in the low and mid-frequency bands were observed.
- A reduction in transfer function gain in the low-frequency band suggested impaired baroreflex control of heart rate.
- Endotoxin also suppressed cardiac vagal modulation, evidenced by decreased RRi variability in the ventilatory frequency band.
Conclusions:
- Endotoxemia significantly disrupts autonomic regulation and impairs baroreflex control of heart rate.
- Frequency spectrum and transfer function analysis are valuable tools for assessing cardiovascular variability changes in endotoxic shock.
- Findings highlight the complex autonomic derangements occurring during sepsis.
