scholarly journals Implantable vagus nerve stimulation system performance is not affected by internal or external defibrillation shocks

2021 ◽  
Author(s):  
Imad Libbus ◽  
Scott R. Stubbs ◽  
Scott T. Mazar ◽  
Scott Mindrebo ◽  
Bruce H. KenKnight ◽  
...  
Keyword(s):  
Vagus Nerve ◽  
Nerve Stimulation ◽  
System Performance ◽  
Vagus Nerve Stimulation ◽  
Pulse Generator ◽  
High Energy ◽  
Cardioverter Defibrillator ◽  
Histologic Evaluation ◽  
The Right

Abstract Purpose Autonomic regulation therapy (ART) for heart failure (HF) is delivered using vagus nerve stimulation (VNS), and has been associated with improvement in cardiac function and HF symptoms. VNS is delivered using an implantable pulse generator (IPG) and a lead placed around the cervical vagus nerve. Because HF patients may receive concomitant cardiac defibrillation therapy, testing was conducted to determine the effect of defibrillation (DF) on VNS system performance. Methods Normal swine (n = 4) with VNS system implants on the right cervical vagus nerve received sequential defibrillation shocks with three defibrillation systems: an implantable cardioverter defibrillator (ICD), a subcutaneous ICD (S-ICD), and an external cardioverter defibrillator (ECD). Each system delivered a series of bipolar high-energy shocks and reverse-polarity high-energy shocks. Results The specified cardiac defibrillation shocks were delivered successfully from each of the three defibrillation systems to all animals. After each shock series, interrogation of the IPG confirmed that software and data were unchanged from pre-programmed values. After all of the defibrillation shocks were delivered, the IPGs underwent and passed comprehensive electrical testing demonstrating proper system function. No shifts in IPG parameters or ART system failures were observed, and histologic evaluation of the vagus nerve revealed no anatomic changes. Conclusions Implantable VNS systems were tested in vivo for immunity to defibrillation via ICD, S-ICD, and ECD, and were found to be unaffected by a series of high-energy defibrillation shocks. These results confirm that ART systems are capable of continuing to function after defibrillation and the cervical vagus nerve is anatomically unaffected.

scholarly journals Effect of defibrillation on the performance of an implantable vagus nerve stimulation system

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Imad Libbus ◽  
Scott R. Stubbs ◽  
Scott T. Mazar ◽  
Scott Mindrebo ◽  
Bruce H. KenKnight ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Function ◽  
Vagus Nerve ◽  
Nerve Stimulation ◽  
Vagus Nerve Stimulation ◽  
Pulse Generator ◽  
High Energy ◽  
Implantable Pulse Generator ◽  
Defibrillation Pulse ◽  
Stimulation System

Abstract Background Vagus Nerve Stimulation (VNS) delivers Autonomic Regulation Therapy (ART) for heart failure (HF), and has been associated with improvement in cardiac function and heart failure symptoms. VNS is delivered using an implantable pulse generator (IPG) and lead with electrodes placed around the cervical vagus nerve. Because HF patients may receive concomitant cardiac defibrillation therapy, testing was conducted to determine the effect of defibrillation (DF) on the VNS system. Methods DF testing was conducted on three ART IPGs (LivaNova USA, Inc.) according to international standard ISO14708-1, which evaluated whether DF had any permanent effects on the system. Each IPG was connected to a defibrillation pulse generator and subjected to a series of high-energy pulses. Results The specified series of pulses were successfully delivered to each of the three devices. All three IPGs passed factory electrical tests, and interrogation confirmed that software and data were unchanged from the pre-programmed values. No shifts in parameters or failures were observed. Conclusions Implantable VNS systems were tested for immunity to defibrillation, and were found to be unaffected by a series of high-energy defibrillation pulses. These results suggest that this VNS system can be used safely and continue to function after patients have been defibrillated.

Implanted vagus nerve stimulation in 126 patients: surgical technique and complications

2020 ◽  
Vol 99 (7) ◽  
Keyword(s):  
Vagus Nerve ◽  
Vocal Cord ◽  
Nerve Stimulation ◽  
Vagus Nerve Stimulation ◽  
Pulse Generator ◽  
Operative Procedure ◽  
Intractable Epilepsy ◽  
Vagal Nerve ◽  
University Hospital ◽  
Nerve Stimulator

Introduction: Vagus nerve stimulation is a palliative treatment for patients with refractory epilepsy to reduce the frequency and intensity of seizures. A bipolar helical electrode is placed around the left vagus nerve at the cervical level and is connected to the pulse generator placed in a subcutaneous pocket, most commonly in the subclavian region. Methods: Between March 1998 and October 2019, we performed 196 procedures related to the vagal nerve stimulation at the Neurosurgery Department in Motol University Hospital. Of these, 126 patients were vagal nerve stimulator implantation surgeries for intractable epilepsy. The cases included 69 female and 57 male patients with mean age at the time of the implantation surgery 22±12.4 years (range 2.1−58.4 years). Results: Nine patients (7.1%) were afflicted by complications related to implantation. Surgical complications included postoperative infection in 1.6%, VNS-associated arrhythmias in 1.6%, jugular vein bleeding in 0.8% and vocal cord paresis in 2.4%. One patient with vocal cord palsy also suffered from severe dysphagia. One patient (0.8%) did not tolerate extra stimulation with magnet due to a prolonged spasm in his throat. The extra added benefit of vagus stimulation in one patient was a significant reduction of previously regular severe headaches. Conclusion: Vagus nerve stimulation is an appropriate treatment for patients with drug-resistant epilepsy who are not candidates for focal resective surgery. Implantation of the vagus nerve stimulator is a relatively safe operative procedure.

scholarly journals Central-peripheral neural network interactions evoked by vagus nerve stimulation: functional consequences on control of cardiac function

2015 ◽  
Vol 309 (10) ◽  
pp. H1740-H1752 ◽  
Author(s):  
Jeffrey L. Ardell ◽  
Pradeep S. Rajendran ◽  
Heath A. Nier ◽  
Bruce H. KenKnight ◽  
J. Andrew Armour
Keyword(s):  
Cardiac Function ◽  
Vagus Nerve ◽  
Nerve Stimulation ◽  
Vagus Nerve Stimulation ◽  
Vagal Afferents ◽  
Intact State ◽  
Mediated Effects ◽  
Functional Consequences ◽  
Anesthetized Dogs ◽  
The Right

Using vagus nerve stimulation (VNS), we sought to determine the contribution of vagal afferents to efferent control of cardiac function. In anesthetized dogs, the right and left cervical vagosympathetic trunks were stimulated in the intact state, following ipsilateral or contralateral vagus nerve transection (VNTx), and then following bilateral VNTx. Stimulations were performed at currents from 0.25 to 4.0 mA, frequencies from 2 to 30 Hz, and a 500-μs pulse width. Right or left VNS evoked significantly greater current- and frequency-dependent suppression of chronotropic, inotropic, and lusitropic function subsequent to sequential VNTx. Bradycardia threshold was defined as the current first required for a 5% decrease in heart rate. The threshold for the right vs. left vagus-induced bradycardia in the intact state (2.91 ± 0.18 and 3.47 ± 0.20 mA, respectively) decreased significantly with right VNTx (1.69 ± 0.17 mA for right and 3.04 ± 0.27 mA for left) and decreased further following bilateral VNTx (1.29 ± 0.16 mA for right and 1.74 ± 0.19 mA for left). Similar effects were observed following left VNTx. The thresholds for afferent-mediated effects on cardiac parameters were 0.62 ± 0.04 and 0.65 ± 0.06 mA with right and left VNS, respectively, and were reflected primarily as augmentation. Afferent-mediated tachycardias were maintained following β-blockade but were eliminated by VNTx. The increased effectiveness and decrease in bradycardia threshold with sequential VNTx suggest that 1) vagal afferents inhibit centrally mediated parasympathetic efferent outflow and 2) the ipsilateral and contralateral vagi exert a substantial buffering capacity. The intact threshold reflects the interaction between multiple levels of the cardiac neural hierarchy.

Airway neutral endopeptidase-like enzyme modulates tachykinin-induced bronchoconstriction in vivo

1988 ◽  
Vol 65 (6) ◽  
pp. 2585-2591 ◽  
Author(s):  
D. J. Dusser ◽  
E. Umeno ◽  
P. D. Graf ◽  
T. Djokic ◽  
D. B. Borson ◽  
...  
Keyword(s):  
Substance P ◽  
Guinea Pig ◽  
Vagus Nerve ◽  
Nerve Stimulation ◽  
Guinea Pigs ◽  
Vagus Nerve Stimulation ◽  
Neutral Endopeptidase ◽  
Base Line ◽  
Pulmonary Resistance

To determine whether neutral endopeptidase (NEP), also called enkephalinase (EC 3.4.24.11), modulates the effects of exogenous and endogenous tachykinins in vivo, we studied the effects of aerosolized phosphoramidon, a specific NEP inhibitor, on the responses to aerosolized substance P (SP) and on the atropine-resistant response to vagus nerve stimulation (10 V, 5 ms for 20 s) in guinea pigs. SP alone (10(-7) to 10(-4) M; each concentration, 7 breaths) caused no change in total pulmonary resistance (RL, P greater than 0.5). Phosphoramidon (10(-4) M, 90 breaths) caused no change either in base-line RL (P greater than 0.5) or in the response to aerosolized acetylcholine (P greater than 0.5). However, in the presence of phosphoramidon, SP (7 breaths) produced a concentration-dependent increase in RL at concentrations greater than or equal to 10(-5) M (P less than 0.001). Phosphoramidon (10(-7) to 10(-4) M; each concentration, 90 breaths) induced a concentration-dependent potentiation of SP-induced bronchoconstriction (10(-4) M, 7 breaths; P less than 0.01). Vagus nerve stimulation (0.5-3 Hz), in the presence of atropine, induced a frequency-dependent increase in RL (P less than 0.001). Phosphoramidon potentiated the atropine-resistant responses to vagus nerve stimulation (P less than 0.001) at frequencies greater than 0.5 Hz. The tachykinin antagonist [D-Arg1,D-Pro2,D-Trp7,9,Leu11]-substance P abolished the effects of phosphoramidon on the atropine-resistant response to vagus nerve stimulation (2 Hz, P less than 0.005). NEP-like activity in tracheal homogenates of guinea pig was inhibited by phosphoramidon with a concentration producing 50% inhibition of 5.3 +/- 0.8 nM.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Vagus Nerve Stimulation Alleviates Hepatic Ischemia and Reperfusion Injury by Regulating Glutathione Production and Transformation

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Haoyang Xia ◽  
Zhongzhong Liu ◽  
Wenjin Liang ◽  
Xianpeng Zeng ◽  
Yi Yang ◽  
...  
Keyword(s):  
Vagus Nerve ◽  
Reperfusion Injury ◽  
Nerve Stimulation ◽  
Vagus Nerve Stimulation ◽  
Hepatic Function ◽  
Glutathione Synthetase ◽  
Ischemia And Reperfusion ◽  
Ischemia And Reperfusion Injury ◽  
Hepatic Ischemia

Inflammation and oxidative stress are pivotal mechanisms for the pathogenesis of ischemia and reperfusion injury (IRI). Vagus nerve stimulation (VNS) may participate in maintaining oxidative homeostasis and response to external stimulus or injury. We investigated whether the in vivo VNS can protect the liver from IRI. In this study, hepatic IRI were induced by ligating the vessels supplying the left and middle lobes of the liver, which underwent 1 h occlusion followed with 24 h reperfusion. VNS was initiated 15 min after ischemia and continued 30 min. Hepatic function, histology, and apoptosis rates were evaluated after 24 h reperfusion. Compared with the IRI group, VNS significantly improved hepatic function. The protective effect was accompanied by a reduction in histological damage in the ischemic area, and the apoptosis rate of hepatocytes has considerable reduction. To find the underlying mechanism, proteomic analysis was performed and differential expression of glutathione synthetase (GSS) and glutathione S-transferase (GST) was observed. Subsequently, test results indicated that VNS upregulated the expression of mRNA and protein of GSS and GST. Meanwhile, VNS increased the plasma levels of glutathione and glutathione peroxidases. We found that VNS alleviated hepatic IRI by upregulating the antioxidant glutathione via the GSS/glutathione/GST signaling pathway.

Noninvasive vagus nerve stimulation and the trigeminal autonomic reflex

Neurology ◽  
2020 ◽  
Vol 94 (10) ◽  
pp. e1085-e1093 ◽  
Author(s):  
Maike Möller ◽  
Jan Mehnert ◽  
Celina F. Schroeder ◽  
Arne May
Keyword(s):  
Functional Connectivity ◽  
Vagus Nerve ◽  
Nerve Stimulation ◽  
Vagus Nerve Stimulation ◽  
Parahippocampal Gyrus ◽  
Pontine Nucleus ◽  
Fmri Session ◽  
Autonomic Reflex ◽  
The Right ◽  
Healthy Participants

ObjectiveThe trigeminal autonomic reflex is a physiologic reflex that plays a crucial role in primary headache and particularly in trigeminal autonomic cephalalgias, such as cluster headache. Previous studies have shown that this reflex can be modulated by the vagus nerve, leading to an inhibition of the parasympathetic output of the reflex in healthy participants. The aim of the present study was to characterize neural correlates of the modulatory effect of noninvasive vagus nerve stimulation (nVNS) on the trigeminal autonomic reflex.MethodsTwenty-one healthy participants were included in a 2-day, randomized, single-blind, within-subject design. The reflex was activated inside the MRI scanner using kinetic oscillation stimulation placed in the left nostril, resulting in an increase in lacrimation. After the first fMRI session, the participants received either sham vagus nerve stimulation or nVNS outside the scanner and underwent a subsequent fMRI session.ResultsnVNS prompted an increase in activation of the left pontine nucleus and a decreased activation of the right parahippocampal gyrus. Psychophysiologic interaction analyses revealed an increased functional connectivity between the left pontine nucleus and the right hypothalamus and a decreased functional connectivity between the right parahippocampal gyrus and the bilateral spinal trigeminal nuclei (sTN).ConclusionsThese findings indicate a complex network involved in the modulatory effect of nVNS including the hypothalamus, the sTN, the pontine nucleus, and the parahippocampal gyrus.

Preservation of a subcutaneous pocket for vagus nerve stimulation pulse generator during magnetoencephalography

2007 ◽  
Vol 107 (6) ◽  
pp. 519-520
Author(s):  
David Donahue ◽  
Rosa Sanchez ◽  
Angel Hernandez ◽  
Saleem Malik ◽  
C. Thomas Black ◽  
...  
Keyword(s):  
Vagus Nerve ◽  
Nerve Stimulation ◽  
Vagus Nerve Stimulation ◽  
Pulse Generator ◽  
Stimulation Pulse

Self-inflicted vocal cord paralysis in two patients with vagus nerve stimulators

2002 ◽  
Vol 96 (5) ◽  
pp. 949-951 ◽  
Author(s):  
James G. Kalkanis ◽  
Priya Krishna ◽  
Jose A. Espinosa ◽  
Dean K. Naritoku
Keyword(s):  
Vagus Nerve ◽  
Vocal Cord ◽  
Nerve Stimulation ◽  
Vagus Nerve Stimulation ◽  
Pulse Generator ◽  
Vocal Cord Paralysis ◽  
Cardiac Pacemakers ◽  
Content Type ◽  
Vagus Nerve Stimulator ◽  
Disabled Patients

✓ Vagus nerve stimulation for treatment of epilepsy is considered safe; reports of severe complications are rare. The authors report on two developmentally disabled patients who experienced vocal cord paralysis weeks after placement of a vagus nerve stimulator. In both cases, traction injury to the vagus nerve resulting in vocal cord paralysis was caused by rotation of the pulse generator at the subclavicular pocket by the patient. Traumatic vagus nerve injury caused by patients tampering with their device has never been reported and may be analogous to a similar phenomenon reported for cardiac pacemakers in the literature. As the use of vagus nerve stimulation becomes widespread it is important to consider the potential for this adverse event.

scholarly journals REFRACTORY EPILEPSY AND VAGUS NERVE STIMULATION: THE WAY FORWARD

2021 ◽  
Vol 5 (3) ◽  
Author(s):  
Bhupendra Chaudhary ◽  
Ansh Chaudhary
Keyword(s):  
Vagus Nerve ◽  
Nerve Stimulation ◽  
Vagus Nerve Stimulation ◽  
Pulse Generator ◽  
Refractory Epilepsy ◽  
Cardiac Innervation ◽  
On Demand ◽  
The Poor ◽  
Us Fda ◽  
Left Vagus

Vagus Nerve Stimulation (VNS) an efficacious neurophysiological modality of treatment for both medically & surgically refractory epilepsy was first implanted in 1988 & later approved by US FDA in 1997. In clinical practice, trains of current are applied intermittently to the left vagus using a pacemaker or AICD like device 'the VNS device'. The device has four components pulse generator, lead, spiral electrodes & a magnet. The pulse generator is implanted beneath left clavicle by a simple surgical method & attached to left vagus nerve via lead & spiral electrodes.[1] The magnet provides an extra edge to control the aura or impending seizure by providing 'On Demand' stimulations. The poor cardiac innervation by left vagus helps to minimize the unwanted or at time dangerous side effects like severe bradycardia, brady arrythmia, or even cardiac asystole.[2]  

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