Heart rate control via vagus nerve stimulation

Area of Science:

• Cardiology
• Neuroscience
• Biomedical Engineering

Background:

• Electrical stimulation of the vagus nerve is known to alter heart rate.
• Medication resistance in tachyarrhythmias necessitates alternative treatment strategies.
• Vagus nerve stimulation (VNS) therapy utilizes implantable leads for neurological conditions.

Purpose of the Study:

• To investigate the efficacy of a clinical vagus nerve stimulation (VNS) lead system for heart rate control.
• To assess the potential of VNS for managing tachycardia in an acute setting.
• To explore VNS as a non-pharmacological approach for cardiac rate regulation.

Main Methods:

• Experiments conducted on three pigs (21-26 kg) under general anesthesia.
• Bipolar helical leads were placed around the right and left vagus nerves.
• Stimulation parameters (frequency, pulse duration, delay, current) were varied; measurements taken during normal sinus rhythm and isoprenaline-induced tachycardia.

Main Results:

• Vagus nerve stimulation (VNS) significantly increased RR-intervals by approximately 40% under optimal ECG-triggered pacing conditions.
• The heart rate reduction effect was rapid (within 5 seconds), reversible, and reproducible.
• No significant difference in efficacy was observed between stimulating the right or left vagus nerve.

Conclusions:

• VNS, when coupled with an external pacing system, effectively decreases heart rate in acute settings.
• The findings support the potential of VNS for managing tachycardia.
• Future fully implantable VNS devices could offer non-pharmacological treatment for conditions involving cardiac dysfunction due to tachycardia.