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Li XY, Liu JQ, Wang Y, Chen Y, Hu WH, Lv YX, Wu Y, Lv J, Tang JM, Kong D. VNS improves VSMC metabolism and arteriogenesis in infarcted hearts through m/n-AChR-Akt-SDF-1α in adult male rats. J Mol Histol 2024; 55:51-67. [PMID: 38165566 PMCID: PMC10830782 DOI: 10.1007/s10735-023-10171-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Accepted: 10/21/2023] [Indexed: 01/04/2024]
Abstract
Vagal nerve stimulation (VNS) provides a novel therapeutic strategy for injured hearts by activating cholinergic anti-inflammatory pathways. However, little information is available on the metabolic pattern and arteriogenesis of VSMCs after MI. VNS has been shown to stimulate the expression of CPT1α, CPT1β, Glut1, Glut4 and SDF-1α in coronary VSMCs, decreasing the number of CD68-positive macrophages while increasing CD206-positive macrophages in the infarcted hearts, leading to a decrease in TNF-α and IL-1β accompanied by a reduced ratio of CD68- and CD206-positive cells, which were dramatically abolished by atropine and mecamylamine in vivo. Knockdown of SDF-1α substantially abrogated the effect of VNS on macrophagecell alteration and inflammatory factors in infarcted hearts. Mechanistically, ACh induced SDF-1α expression in VSMCs in a dose-dependent manner. Conversely, atropine, mecamylamine, and a PI3K/Akt inhibitor completely eliminated the effect of ACh on SDF-1α expression. Functionally, VNS promoted arteriogenesis and improved left ventricular performance, which could be abolished by Ad-shSDF-1α. Thus, VNS altered the VSMC metabolism pattern and arteriogenesis to repair the infarcted heart by inducing SDF-1α expression, which was associated with the m/nAChR-Akt signaling pathway.
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Affiliation(s)
- Xing-Yuan Li
- Department of Physiology, Faculty of Basic Medical Sciences, Zunyi Medicical University, Zunyi, 563006, Guizhou, People's Republic of China
- Hubei Key Laboratory of Embryonic Stem Cell Research, Faculty of Basic Medical Sciences, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China
| | - Jia-Qi Liu
- Nursing College, Hubei Province Chinese Medicine Hospital, Hubei University of Traditional Chinese Medicine, Wuhan, 430065, Hubei, People's Republic of China
| | - Yan Wang
- Department of Physiology, Faculty of Basic Medical Sciences, Zunyi Medicical University, Zunyi, 563006, Guizhou, People's Republic of China
| | - Yan Chen
- Department of Physiology, Faculty of Basic Medical Sciences, Zunyi Medicical University, Zunyi, 563006, Guizhou, People's Republic of China
| | - Wen-Hui Hu
- Department of Physiology, Faculty of Basic Medical Sciences, Zunyi Medicical University, Zunyi, 563006, Guizhou, People's Republic of China
| | - Yan-Xia Lv
- Hubei Key Laboratory of Embryonic Stem Cell Research, Faculty of Basic Medical Sciences, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China
- Department of Physiology, Faculty of Basic Medical Sciences, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China
| | - Yan Wu
- Hubei Key Laboratory of Embryonic Stem Cell Research, Faculty of Basic Medical Sciences, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China
- Department of Physiology, Faculty of Basic Medical Sciences, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China
| | - Jing Lv
- Institute of Basic Medical Sciences, Institute of Biomedicine, Hubei University of Medicine, Hubei, 442000, People's Republic of China.
| | - Jun-Ming Tang
- Hubei Key Laboratory of Embryonic Stem Cell Research, Faculty of Basic Medical Sciences, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China.
- Department of Physiology, Faculty of Basic Medical Sciences, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China.
- Institute of Basic Medical Sciences, Institute of Biomedicine, Hubei University of Medicine, Hubei, 442000, People's Republic of China.
| | - Deying Kong
- Department of Physiology, Faculty of Basic Medical Sciences, Zunyi Medicical University, Zunyi, 563006, Guizhou, People's Republic of China.
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Libbus I, Premchand RK, Sharma K, Mittal S, Monteiro R, Amurthur B, KenKnight BH, DiCarlo LA, Anand IS. Persistent Autonomic Engagement and Cardiac Control After Four or More Years of Autonomic Regulation Therapy Using Vagus Nerve Stimulation. Front Physiol 2022; 13:853617. [PMID: 35360224 PMCID: PMC8963780 DOI: 10.3389/fphys.2022.853617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 02/16/2022] [Indexed: 11/13/2022] Open
Abstract
Introduction Although heart failure (HF) outcomes have improved dramatically with the use of guideline directed medical therapy and implantable devices, the overall prognosis of patients with HF and reduced ejection fraction (HFrEF) remains poor. Autonomic Regulation Therapy (ART) using chronic vagus nerve stimulation (VNS) has been evaluated in the ANTHEM-HF study, using changes in heart rate (HR) dynamics as a biomarker of autonomic nervous system engagement and cardiac control to guide VNS titration. ART was associated with sustained improvement in cardiac function and HF symptoms in patients with HFrEF and persistent HF symptoms despite guideline-directed medical therapy (GDMT). We sought to determine whether the responsiveness of the autonomic nervous system to ART, as reflected in HR response to vagus stimulation during the VNS duty cycle, is maintained after long-term chronic VNS administration. Methods Fifteen patients with HFrEF and implanted with a VNS systems in the ANTHEM-HF study were evaluated after 4.7 ± 0.3 years (range: 4.0-5.0 years) of chronic ART. ECG electrodes were placed on each patient's wrists, and ECG rhythm strips were recorded. Instantaneous HR time series was computed at each patient's chronically programmed VNS intensity and during progressively increasing VNS intensity. HR during active stimulation (on-time) was compared to HR just prior to initiation of each stimulation cycle (off-time). Results Persistent autonomic engagement was observed in a majority of patients (11 of 15, 73%) after chronic ART for four or more years. The average magnitude of HR reduction during ART on-time in all patients was 2.4 ± 3.2 bpm at the chronically programmed VNS pulse parameter settings. Conclusion Autonomic responsiveness to VNS persists in patients with HFrEF who received chronic ART for up to 5 years as a supplement to GDMT. This suggests that the effects of ART on autonomic engagement and cardiac control remain durable over time. Clinical Trial Registration [ClinicalTrials.gov], identifier [#NCT01823887, CTRI registration #CTRI/2012/05/002681].
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Affiliation(s)
- Imad Libbus
- LivaNova USA, Inc., Houston, TX, United States
| | | | - Kamal Sharma
- Sanjivani Super Specialty Hospitals, Ahmedabad, India
| | | | | | | | | | | | - Inder S. Anand
- Emeritus, University of Minnesota, Minneapolis, MN, United States
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3
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Abstract
Vagal nerve stimulation (VNS) has a strong pathophysiological rationale as a potentially beneficial treatment for heart failure with reduced ejection fraction. Despite several promising preclinical studies and pilot clinical studies, the two large, controlled trials—NECTAR-HF and INOVATE-HF—failed to demonstrate the expected benefit. It is likely that clinical application of VNS in phase III studies was performed before a sufficient degree of understanding of the complex pathophysiology of autonomic electrical modulation had been achieved, therefore leading to an underestimation of its potential benefit. More knowledge on the complex dose–response issue of VNS (i.e., pulse amplitude, frequency, duration and duty cycle) has been gathered since these trials and a new randomized study is currently underway with an adaptive design and a refined approach in an attempt to deliver the proper dose to a more selected group of patients.
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Affiliation(s)
- Veronica Dusi
- Division of Cardiology, Department of Medical Sciences, Citta della Salute e della Scienza Hospital, University of Turin, Corso Bramante 88, 10126, Turin, Italy.
| | - Gaetano Maria De Ferrari
- Division of Cardiology, Department of Medical Sciences, Citta della Salute e della Scienza Hospital, University of Turin, Corso Bramante 88, 10126, Turin, Italy
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Hsieh CM, Lin WC, Peng HY, Chen HC, Ho YC, Li CJ, Wu XG, Chung JY, Lee SD, Lin TB. Shoulder transcutaneous electric nerve stimulation decreases heart rate via potentiating vagal tone. Sci Rep 2021; 11:19168. [PMID: 34580404 PMCID: PMC8476641 DOI: 10.1038/s41598-021-98690-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 09/07/2021] [Indexed: 11/23/2022] Open
Abstract
By enhancing vagal activity, auricle transcutaneous electric nerve stimulation (TENS) is developed as a non-invasive therapy for heart failure. Nevertheless, though shoulder TENS used for treating adhesive capsulitis could affect vagal tone, its potential impact on heart functions remains unclear. In this study, electrocardiogram (ECG) and heart rate (HR) of subjects in response to sham, right-sided, or left-sided shoulder TENS (TENS-S, TENS-R, and TENS-L, respectively; 5 min) were recorded and analyzed. During the stimulation period, TENS-R constantly and TENS-L transiently decreased the HR of subjects; both TENS-R and TENS-L increased powers of the low- and high-frequency spectra. While TENS-R exhibiting no effect, TENS-L increased the ratio of low/high-frequency power spectrum indicating TENS-R decreased the HR through potentiating cardiac vagal tone. Collectively, these results suggest TENS could be an early and non-invasive therapy for heart failure patients before considering implant devices or devices are not feasible; moreover, therapists/physicians need to carefully monitor the potential adverse events during treatment for patient safety. Trial registration: The study protocol was registered in ClinicalTrials.gov (NCT03982472; 11/06/2019).
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Affiliation(s)
- Chun-Ming Hsieh
- Division of Physical Therapy, St. Paul's Hospital, Taoyuan, Taiwan
| | - Wan-Chen Lin
- Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, No. 250, Wu-Hsing Street, Taipei, 11031, Taiwan.,National Taiwan University Hospital, Taipei, Taiwan
| | - Hsien-Yu Peng
- Department of Medicine, Mackay Medical College, New Taipei, Taiwan
| | - Huang-Chung Chen
- Department of Rehabilitation, St. Paul's Hospital, Taoyuan, Taiwan
| | - Yu-Cheng Ho
- Department of Medicine, Mackay Medical College, New Taipei, Taiwan
| | - Chi-Jui Li
- Division of Physical Therapy, St. Paul's Hospital, Taoyuan, Taiwan
| | - Xi-Guan Wu
- Division of Physical Therapy, St. Paul's Hospital, Taoyuan, Taiwan
| | - Jen-Yi Chung
- Division of Physical Therapy, St. Paul's Hospital, Taoyuan, Taiwan
| | - Shin-Da Lee
- Department of Occupational Therapy, Asia University, Taichung, Taiwan.,Department of Physical Therapy, Graduate Institute of Rehabilitation Science, China Medical University, Taichung, Taiwan.,School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Tzer-Bin Lin
- Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, No. 250, Wu-Hsing Street, Taipei, 11031, Taiwan. .,Department of Bioinformatics and Medical Engineering, Asia University, Taichung, Taiwan. .,Department of Biotechnology, Asia University, Taichung, Taiwan. .,Cell Physiology and Molecular Image Research Center, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
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Debnath S, Levy TJ, Bellehsen M, Schwartz RM, Barnaby DP, Zanos S, Volpe BT, Zanos TP. A method to quantify autonomic nervous system function in healthy, able-bodied individuals. Bioelectron Med 2021; 7:13. [PMID: 34446089 PMCID: PMC8394599 DOI: 10.1186/s42234-021-00075-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Accepted: 07/20/2021] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND The autonomic nervous system (ANS) maintains physiological homeostasis in various organ systems via parasympathetic and sympathetic branches. ANS function is altered in common diffuse and focal conditions and heralds the beginning of environmental and disease stresses. Reliable, sensitive, and quantitative biomarkers, first defined in healthy participants, could discriminate among clinically useful changes in ANS function. This framework combines controlled autonomic testing with feature extraction during physiological responses. METHODS Twenty-one individuals were assessed in two morning and two afternoon sessions over two weeks. Each session included five standard clinical tests probing autonomic function: squat test, cold pressor test, diving reflex test, deep breathing, and Valsalva maneuver. Noninvasive sensors captured continuous electrocardiography, blood pressure, breathing, electrodermal activity, and pupil diameter. Heart rate, heart rate variability, mean arterial pressure, electrodermal activity, and pupil diameter responses to the perturbations were extracted, and averages across participants were computed. A template matching algorithm calculated scaling and stretching features that optimally fit the average to an individual response. These features were grouped based on test and modality to derive sympathetic and parasympathetic indices for this healthy population. RESULTS A significant positive correlation (p = 0.000377) was found between sympathetic amplitude response and body mass index. Additionally, longer duration and larger amplitude sympathetic and longer duration parasympathetic responses occurred in afternoon testing sessions; larger amplitude parasympathetic responses occurred in morning sessions. CONCLUSIONS These results demonstrate the robustness and sensitivity of an algorithmic approach to extract multimodal responses from standard tests. This novel method of quantifying ANS function can be used for early diagnosis, measurement of disease progression, or treatment evaluation. TRIAL REGISTRATION This study registered with Clinicaltrials.gov , identifier NCT04100486 . Registered September 24, 2019, https://www.clinicaltrials.gov/ct2/show/NCT04100486 .
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Affiliation(s)
- Shubham Debnath
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, 350 Community Dr, Manhasset, NY, 11030, USA
| | - Todd J Levy
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, 350 Community Dr, Manhasset, NY, 11030, USA
| | - Mayer Bellehsen
- Department of Psychiatry, Unified Behavioral Health Center and World Trade Center Health Program, Northwell Health, Bay Shore, NY, USA
| | - Rebecca M Schwartz
- Department of Occupational Medicine, Epidemiology and Prevention, Northwell Health, Feinstein Institutes for Medical Research, Manhasset, NY, USA
- Center for Disaster Health, Trauma, and Resilience, New York, NY, USA
- Northwell Health, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA
| | - Douglas P Barnaby
- Northwell Health, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA
- Northwell Health, Institute of Health Innovations and Outcomes Research, Feinstein Institutes for Medical Research, Manhasset, NY, USA
| | - Stavros Zanos
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, 350 Community Dr, Manhasset, NY, 11030, USA
| | - Bruce T Volpe
- Northwell Health, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA
- Northwell Health, Institute of Molecular Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, USA
| | - Theodoros P Zanos
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, 350 Community Dr, Manhasset, NY, 11030, USA.
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Stavrakis S, Kulkarni K, Singh JP, Katritsis DG, Armoundas AA. Autonomic Modulation of Cardiac Arrhythmias: Methods to Assess Treatment and Outcomes. JACC Clin Electrophysiol 2021; 6:467-483. [PMID: 32439031 DOI: 10.1016/j.jacep.2020.02.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 02/06/2020] [Accepted: 02/14/2020] [Indexed: 02/08/2023]
Abstract
The autonomic nervous system plays a central role in the pathogenesis of multiple cardiac arrhythmias, including atrial fibrillation and ventricular tachycardia. As such, autonomic modulation represents an attractive therapeutic approach in these conditions. Notably, autonomic modulation exploits the plasticity of the neural tissue to induce neural remodeling and thus obtain therapeutic benefit. Different forms of autonomic modulation include vagus nerve stimulation, tragus stimulation, renal denervation, baroreceptor activation therapy, and cardiac sympathetic denervation. This review seeks to highlight these autonomic modulation therapeutic modalities, which have shown promise in early preclinical and clinical trials and represent exciting alternatives to standard arrhythmia treatment. We also present an overview of the various methods used to assess autonomic tone, including heart rate variability, skin sympathetic nerve activity, and alternans, which can be used as surrogate markers and predictors of the treatment effect. Although the use of autonomic modulation to treat cardiac arrhythmias is supported by strong preclinical data and preliminary studies in humans, in light of the disappointing results of a number of recent randomized clinical trials of autonomic modulation therapies in heart failure, the need for optimization of the stimulation parameters and rigorous patient selection based on appropriate biomarkers cannot be overemphasized.
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Affiliation(s)
- Stavros Stavrakis
- Heart Rhythm Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA.
| | - Kanchan Kulkarni
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Jagmeet P Singh
- Cardiology Division, Cardiac Arrhythmia Service, Massachusetts General Hospital, Boston, Massachusetts, USA
| | | | - Antonis A Armoundas
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, Massachusetts, USA; Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
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7
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Yaghouby F, Jang K, Hoang U, Asgari S, Vasudevan S. Sex Differences in Vagus Nerve Stimulation Effects on Rat Cardiovascular and Immune Systems. Front Neurosci 2020; 14:560668. [PMID: 33240036 PMCID: PMC7677457 DOI: 10.3389/fnins.2020.560668] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Accepted: 09/22/2020] [Indexed: 01/09/2023] Open
Abstract
Background Investigations into the benefits of vagus nerve stimulation (VNS) through pre-clinical and clinical research have led to promising findings for treating several disorders. Despite proven effectiveness of VNS on conditions such as epilepsy and depression, understanding of off-target effects and contributing factors such as sex differences can be beneficial to optimize therapy design. New Methods In this article, we assessed longitudinal effects of VNS on cardiovascular and immune systems, and studied potential sex differences using a rat model of long-term VNS. Rats were implanted with cuff electrodes around the left cervical vagus nerve for VNS, and wireless physiological monitoring devices for continuous monitoring of cardiovascular system using electrocardiogram (ECG) signals. ECG morphology and heart rate variability (HRV) features were extracted to assess cardiovascular changes resulting from VNS in short-term and long-term timescales. We also assessed VNS effects on expression of inflammatory cytokines in blood during the course of the experiment. Statistical analysis was performed to compare results between Treatment and Sham groups, and between male and female animals from Treatment and Sham groups. Results Considerable differences between male and female rats in cardiovascular effects of VNS were observed in multiple cardiovascular features. However, the effects seemed to be transient with approximately 1-h recovery after VNS. While short-term cardiovascular effects were mainly observed in male rats, females in general showed more significant long-term effects even after VNS stopped. We did not observe notable changes or sex differences in systemic cytokine levels resulting from VNS. Comparison With Existing Methods Compared to existing methods, our study design incorporated wireless physiological monitoring and systemic blood cytokine level analysis, along with long-term VNS experiments in unanesthetized rats to study sex differences. Conclusion The contribution of sex differences for long-term VNS off-target effects on cardiovascular and immune systems was assessed using awake behaving rats. Although VNS did not change the concentration of inflammatory biomarkers in systemic circulation for male and female rats, we observed significant differences in cardiovascular effects of VNS characterized using ECG morphology and HRV analyses.
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Affiliation(s)
- Farid Yaghouby
- U.S. Food and Drug Administration, Center for Devices and Radiological Health (CDRH), Office of Science and Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD, United States
| | - Kee Jang
- U.S. Food and Drug Administration, Center for Devices and Radiological Health (CDRH), Office of Science and Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD, United States
| | - Uyen Hoang
- U.S. Food and Drug Administration, Center for Devices and Radiological Health (CDRH), Office of Science and Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD, United States
| | - Sepideh Asgari
- U.S. Food and Drug Administration, Center for Devices and Radiological Health (CDRH), Office of Science and Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD, United States
| | - Srikanth Vasudevan
- U.S. Food and Drug Administration, Center for Devices and Radiological Health (CDRH), Office of Science and Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD, United States
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Xue N, Martinez ID, Sun J, Cheng Y, Liu C. Flexible multichannel vagus nerve electrode for stimulation and recording for heart failure treatment. Biosens Bioelectron 2018; 112:114-119. [DOI: 10.1016/j.bios.2018.04.043] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 04/17/2018] [Accepted: 04/18/2018] [Indexed: 01/27/2023]
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9
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Lee SW, Kulkarni K, Annoni EM, Libbus I, KenKnight BH, Tolkacheva EG. Stochastic vagus nerve stimulation affects acute heart rate dynamics in rats. PLoS One 2018; 13:e0194910. [PMID: 29590213 PMCID: PMC5874066 DOI: 10.1371/journal.pone.0194910] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 03/13/2018] [Indexed: 01/09/2023] Open
Abstract
Vagus nerve stimulation (VNS) is an approved therapy for treatment of epilepsy and depression. While also shown to be promising in several preclinical and clinical studies to treat cardiovascular diseases, optimal therapeutic stimulation paradigms are still under investigation. Traditionally, parameters such as frequency, current, and duty cycle are used to adjust the efficacy of VNS therapy. This study explored the effect of novel stochastic VNS (S-VNS) on acute heart rate (HR) dynamics. The effect of S-VNS was evaluated in Sprague Dawley rats by comparing the acute HR and HR variability (HRV) responses to standard, periodic VNS (P-VNS) across different frequencies (FREQs, 10-30 Hz). Our results demonstrate that both S-VNS and P-VNS produced negative chronotropic effects in a FREQ-dependent manner with S-VNS inducing a significantly smaller drop in HR at 10 Hz and 20 Hz compared to P-VNS (p<0.05). S-VNS demonstrated a FREQ-dependent drop in the SD1/SD2 ratio, a measure of HRV, which was absent in P-VNS, suggesting that S-VNS may acutely modulate the nonlinear relationship between short- and long-term HRV. In conclusion, S-VNS is a novel stimulation procedure that may provide different physiological outcomes from standard P-VNS, as indicated by our analysis of HR dynamics. Our study provides a rationale for further detailed investigations into the therapeutic potential of S-VNS as a novel neuromodulation technique.
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Affiliation(s)
- Steven W Lee
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States of America
| | - Kanchan Kulkarni
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States of America
| | - Elizabeth M Annoni
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States of America
| | - Imad Libbus
- LivaNova, PLC (Cyberonics, Inc.), Houston, TX, United States of America
| | - Bruce H KenKnight
- LivaNova, PLC (Cyberonics, Inc.), Houston, TX, United States of America
| | - Elena G Tolkacheva
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States of America
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