Selective vagal nerve stimulation allowed blood pressure drops to be adjusted to 60% of the initial value in rats without triggering significant bradycardia or bradypnea.
Does selective vagal nerve stimulation reduce blood pressure without causing bradycardia and bradypnea in a rat model?
A novel method for selective vagal nerve stimulation effectively reduces blood pressure in rats without causing the common side effects of bradycardia and bradypnea.
OBJECTIVE: Hypertension is the largest threat to patient health and a burden to health care systems. Despite various options, 30% of patients do not respond sufficiently to medical treatment. Mechanoreceptors in the aortic arch relay blood pressure (BP) levels through vagal nerve (VN) fibers to the brainstem and trigger the baroreflex, lowering the BP. Selective electrical stimulation of these nerve fibers reduced BP in rats. However, there is no technique described to localize and stimulate these fibers inside the VN without inadvertent stimulation of non-baroreceptive fibers causing side effects like bradycardia and bradypnea. APPROACH: We present a novel method for selective VN stimulation to reduce BP without the aforementioned side effects. Baroreceptor compound activity of rat VN (n = 5) was localized using a multichannel cuff electrode, true tripolar recording and a coherent averaging algorithm triggered by BP or electrocardiogram. MAIN RESULTS: Tripolar stimulation over electrodes near the barofibers reduced the BP without triggering significant bradycardia and bradypnea. The BP drop was adjusted to 60% of the initial value by varying the stimulation pulse width and duration, and lasted up to five times longer than the stimulation. SIGNIFICANCE: The presented method is robust to impedance changes, independent of the electrode's relative position, does not compromise the nerve and can run on implantable, ultra-low power signal processors.
Plachta et al. (Thu,) conducted a other in Hypertension (n=5). Selective vagal nerve stimulation was evaluated on Blood pressure reduction. Selective vagal nerve stimulation allowed blood pressure drops to be adjusted to 60% of the initial value in rats without triggering significant bradycardia or bradypnea.