Baroreflex control model for cardiovascular system subjected to postural changes under normal and orthostatic...

Area of Science:

• Physiology
• Biomedical Engineering
• Computational Biology

Background:

• Baroreflex dysfunction is a key factor in cardiovascular system irregularities.
• Baroreflex gain and buffering capacity significantly impact short-term blood pressure control.
• Understanding the interplay between the autonomic nervous system and cardiovascular system is crucial for blood pressure regulation.

Purpose of the Study:

• To develop an integrated analytical model of the baroreflex and cardiovascular system.
• To investigate the complex interactions between the autonomic nervous system and cardiovascular system.
• To analyze short-term blood pressure control mechanisms, including responses to postural changes and gravity.

Main Methods:

• An integrated model incorporating Mulier's heart model, systemic vasculature, a stress-strain based Voigt baroreceptor model, and Hodgkin-Huxley based autonomic nervous control was developed.
• Simulations were performed using both non-pulsatile and pulsatile heart models.
• Model validation included supine to standing transitions under gravity, normal postural changes, and simulations of orthostatic hypotension and hypertension.

Main Results:

• The integrated model successfully simulated blood volume distribution changes due to gravity during postural shifts.
• The model demonstrated efficiency in simulating normal postural changes (supine to standing, standing to supine) and pathological conditions (orthostatic hypotension/hypertension).
• The pulsatile model exhibited robustness when subjected to mean arterial pressure disturbances during various postural changes.

Conclusions:

• The developed integrated model provides a valuable tool for studying baroreflex control and cardiovascular system dynamics.
• The model accurately captures short-term blood pressure regulation influenced by autonomic nervous system activity and postural changes.
• This computational approach can aid in understanding cardiovascular disorders and evaluating therapeutic strategies.