Novel therapeutic strategy against central baroreflex failure: a bionic baroreflex system

Area of Science:

• Biomedical Engineering
• Neuroscience
• Cardiovascular Physiology

Background:

• Central baroreflex failure, seen in Shy-Drager syndrome and spinal cord injuries, causes severe orthostatic hypotension.
• This condition often leads to patients being bedridden due to the inability to regulate blood pressure upon standing.
• A novel therapeutic strategy involves creating an artificial feedback system to automatically regulate sympathetic vasomotor tone.

Purpose of the Study:

• To develop and test the efficacy of a bionic baroreflex system (BBS) in a rat model.
• To create an artificial feedback control system capable of regulating sympathetic vasomotor tone.
• To address central baroreflex failure and its associated severe orthostatic hypotension.

Main Methods:

• A prototype BBS was constructed using a pressure sensor in the aortic arch and stimulation electrodes in the greater splanchnic nerve.
• System identification using white noise estimated normal baroreflex dynamics to program the BBS computer.
• The BBS was evaluated in anesthetized rats by inducing hypotension through sympathetic withdrawal.

Main Results:

• The BBS computer functioned as an artificial vasomotor center, mimicking native baroreflex dynamics.
• System identification revealed the artificial vasomotor center's transfer function as a high-pass filter.
• In rats, the BBS suppressed a rapid fall in systemic arterial pressure (SAP) by 22+/-6 mm Hg at the nadir and 16+/-5 mm Hg at the plateau, comparable to native baroreflex function.

Conclusions:

• The developed bionic baroreflex system demonstrated feasibility in a rat model.
• The BBS effectively compensated for central baroreflex failure.
• This approach holds potential for treating patients with conditions causing baroreflex impairment.