Abstract
The cervical vagus nerve (VN) conducts efferent and afferent signals involved in neurocardiogenic syncope. We investigated whether direct current impulses (DCI) block effects of VN stimulation (VNS). Methods In anesthetized dogs (n=7) VN were instrumented with bipolar electrode proximally and distally, to do VNS and DCI. We measured changes in heart rate (HR) and mean arterial blood pressure (BP). Results Proximal efferent VNS (20Hz, 0.9–2.5V) reduced the resting HR by 57–71%. Distal DCI (2.2–4.5V) restored HR to 82–94% of baseline rate within 1–2 seconds and was sustained over the duration of the stimulus (15–30 seconds). BP dropped substantially with bradycardia (34–35% of baseline) but no significant changes in BP occurred while HR was maintained by pacing. Distal R-VNS produced a moderate decrease 9–18 mmHg in BP while L-VNS produced an increase of 20–48 mmHg. which was also attenuated by by proximal DCI. Conclusion It is feasible to interrupt vagal-mediated bradycardia and hypotension with appropriately delivered electrical impulses. Further study is needed to evaluate the long-term effects of DCI before translation into viable therapy.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
