1
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Oh S. Neuromodulation for Atrial Fibrillation Control. Korean Circ J 2024; 54:223-232. [PMID: 38654454 PMCID: PMC11109834 DOI: 10.4070/kcj.2024.0050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 02/13/2024] [Indexed: 04/26/2024] Open
Abstract
Trigger and functional substrate are related to the tone of autonomic nervous system, and the role of the autonomic nerve is more significant in paroxysmal atrial fibrillation (AF) compared to non-paroxysmal AF. We have several options for neuromodulation to help to manage patients with AF. Neuromodulation targets can be divided into efferent and afferent pathways. On the efferent side, block would be an intuitive approach. However, permanent block is hard to achieve due to completeness of the procedure and reinnervation issues. Temporary block such as botulinum toxin injection into ganglionated plexi would be a possible option for post-cardiac surgery AF. Low-level subthreshold stimulation could also prevent AF, but the invasiveness of the procedure is the barrier for the general use. On the afferent side, block is also an option. Various renal denervation approaches are currently under investigation. Auditory vagus nerve stimulation is one of the representative low-level afferent stimulation methods. This technique is noninvasive and easy to apply, so it has the potential to be widely utilized if its efficacy is confirmed.
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Affiliation(s)
- Seil Oh
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
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2
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Rajendran PS, Hadaya J, Khalsa SS, Yu C, Chang R, Shivkumar K. The vagus nerve in cardiovascular physiology and pathophysiology: From evolutionary insights to clinical medicine. Semin Cell Dev Biol 2024; 156:190-200. [PMID: 36641366 PMCID: PMC10336178 DOI: 10.1016/j.semcdb.2023.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 01/01/2023] [Accepted: 01/03/2023] [Indexed: 01/13/2023]
Abstract
The parasympathetic nervous system via the vagus nerve exerts profound influence over the heart. Together with the sympathetic nervous system, the parasympathetic nervous system is responsible for fine-tuned regulation of all aspects of cardiovascular function, including heart rate, rhythm, contractility, and blood pressure. In this review, we highlight vagal efferent and afferent innervation of the heart, with a focus on insights from comparative biology and advances in understanding the molecular and genetic diversity of vagal neurons, as well as interoception, parasympathetic dysfunction in heart disease, and the therapeutic potential of targeting the parasympathetic nervous system in cardiovascular disease.
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Affiliation(s)
| | - Joseph Hadaya
- University of California, Los Angeles (UCLA) Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; UCLA Molecular, Cellular, and Integrative Physiology Program, Los Angeles, CA, USA
| | - Sahib S Khalsa
- Laureate Institute for Brain Research, Tulsa, Ok, USA; Oxley College of Health Sciences, University of Tulsa, Tulsa, Ok, USA
| | - Chuyue Yu
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA; Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA
| | - Rui Chang
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA; Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA
| | - Kalyanam Shivkumar
- University of California, Los Angeles (UCLA) Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; UCLA Molecular, Cellular, and Integrative Physiology Program, Los Angeles, CA, USA.
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3
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Wu Z, Liao J, Liu Q, Zhou S, Chen M. Chronic vagus nerve stimulation in patients with heart failure: challenge or failed translation? Front Cardiovasc Med 2023; 10:1052471. [PMID: 37534273 PMCID: PMC10390725 DOI: 10.3389/fcvm.2023.1052471] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Accepted: 05/31/2023] [Indexed: 08/04/2023] Open
Abstract
Autonomic imbalance between the sympathetic and parasympathetic nervous systems contributes to the progression of chronic heart failure (HF). Preclinical studies have demonstrated that various neuromodulation strategies may exert beneficial cardioprotective effects in preclinical models of HF. Based on these encouraging experimental data, vagus nerve stimulation (VNS) has been assessed in patients with HF with a reduced ejection fraction. Nevertheless, the main trials conducted thus far have yielded conflicting findings, questioning the clinical efficacy of VNS in this context. This review will therefore focus on the role of the autonomic nervous system in HF pathophysiology and VNS therapy, highlighting the potential reasons behind the discrepancy between preclinical and clinical studies.
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Affiliation(s)
- Zhihong Wu
- Department of Cardiovascular, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Jiaying Liao
- Department of Nephrology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Qiming Liu
- Department of Cardiovascular, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Shenghua Zhou
- Department of Cardiovascular, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Mingxian Chen
- Department of Cardiovascular, The Second Xiangya Hospital of Central South University, Changsha, China
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4
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Takla M, Saadeh K, Tse G, Huang CLH, Jeevaratnam K. Ageing and the Autonomic Nervous System. Subcell Biochem 2023; 103:201-252. [PMID: 37120470 DOI: 10.1007/978-3-031-26576-1_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
The vertebrate nervous system is divided into central (CNS) and peripheral (PNS) components. In turn, the PNS is divided into the autonomic (ANS) and enteric (ENS) nervous systems. Ageing implicates time-related changes to anatomy and physiology in reducing organismal fitness. In the case of the CNS, there exists substantial experimental evidence of the effects of age on individual neuronal and glial function. Although many such changes have yet to be experimentally observed in the PNS, there is considerable evidence of the role of ageing in the decline of ANS function over time. As such, this chapter will argue that the ANS constitutes a paradigm for the physiological consequences of ageing, as well as for their clinical implications.
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Affiliation(s)
| | | | - Gary Tse
- Kent and Medway Medical School, Canterbury, UK
- University of Surrey, Guildford, UK
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5
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Giannoni A, Gentile F, Buoncristiani F, Borrelli C, Sciarrone P, Spiesshoefer J, Bramanti F, Iudice G, Javaheri S, Emdin M, Passino C. Chemoreflex and Baroreflex Sensitivity Hold a Strong Prognostic Value in Chronic Heart Failure. JACC: HEART FAILURE 2022; 10:662-676. [DOI: 10.1016/j.jchf.2022.02.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 02/07/2022] [Accepted: 02/11/2022] [Indexed: 02/07/2023]
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6
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Harper AA, Adams DJ. Electrical properties and synaptic transmission in mouse intracardiac ganglion neurons in situ. Physiol Rep 2021; 9:e15056. [PMID: 34582125 PMCID: PMC8477906 DOI: 10.14814/phy2.15056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 08/25/2021] [Accepted: 09/08/2021] [Indexed: 12/19/2022] Open
Abstract
The intrinsic cardiac nervous system represents the final site of signal integration for neurotransmission to the myocardium to enable local control of cardiac performance. The electrophysiological characteristics and ganglionic transmission of adult mouse intrinsic cardiac ganglion (ICG) neurons were investigated using a whole-mount ganglion preparation of the excised right atrial ganglion plexus and intracellular microelectrode recording techniques. The passive and active electrical properties of ICG neurons and synaptic transmission including synaptic response strength and efficacy as a function of stimulation frequency were examined. The resting membrane potential and input resistance of ICG neurons were -47.9 ± 4.0 mV and 197.2 ± 81.5 MΩ, respectively. All neurons had somatic action potentials with overshoots of >+15 mV and after-hyperpolarizations having an average of 10 mV amplitude and ~45 ms half duration. Phasic discharge activities were recorded from the majority of neurons studied and several types of excitatory synaptic responses were recorded following inputs from the vagus or interganglionic nerve trunk(s). Most postganglionic neurons (>75%) received a strong, suprathreshold synaptic input and reliably followed high-frequency repetitive nerve stimulation up to at least 50 Hz. Nerve-evoked synaptic transmission was blocked by extracellular Cd2+ , ω-conotoxin CVIE, or α-conotoxin RegIIA, a selective α3-containing nicotinic acetylcholine receptor antagonist. Synaptic transmission and the electrical properties of murine ICG neurons contribute to the pattern of discharge which regulates chronotropic, dromotropic, and inotropic elements of cardiac function.
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Affiliation(s)
- Alexander A. Harper
- Illawarra Health and Medical Research Institute (IHMRI)University of WollongongWollongongNew South WalesAustralia
| | - David J. Adams
- Illawarra Health and Medical Research Institute (IHMRI)University of WollongongWollongongNew South WalesAustralia
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7
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Floras JS. The 2021 Carl Ludwig Lecture. Unsympathetic autonomic regulation in heart failure: patient-inspired insights. Am J Physiol Regul Integr Comp Physiol 2021; 321:R338-R351. [PMID: 34259047 DOI: 10.1152/ajpregu.00143.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Defined as a structural or functional cardiac abnormality accompanied by symptoms, signs, or biomarkers of altered ventricular pressures or volumes, heart failure also is a state of autonomic disequilibrium. A large body of evidence affirms that autonomic disturbances are intrinsic to heart failure; basal or stimulated sympathetic nerve firing or neural norepinephrine (NE) release more often than not exceed homeostatic need, such that an initially adaptive adrenergic or vagal reflex response becomes maladaptive. The magnitude of such maladaptation predicts prognosis. This Ludwig lecture develops two theses: the elucidation and judiciously targeted amelioration of maladaptive autonomic disturbances offers opportunities to complement contemporary guideline-based heart failure therapy, and serendipitous single-participant insights, acquired in the course of experimental protocols with entirely different intent, can generate novel insight, inform mechanisms, and launch entirely new research directions. I précis six elements of our current synthesis of the causes and consequences of maladaptive sympathetic disequilibrium in heart failure, shaped by patient-inspired epiphanies: arterial baroreceptor reflex modulation, excitation stimulated by increased cardiac filling pressure, paradoxical muscle sympathetic activation as a peripheral neurogenic constraint on exercise capacity, renal sympathetic restraint of natriuresis, coexisting sleep apnea, and augmented chemoreceptor reflex sensitivity and then conclude by envisaging translational therapeutic opportunities.
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Affiliation(s)
- John S Floras
- University Health Network and Sinai Health Division of Cardiology, Toronto General Hospital Research Institute and Department of Medicine, University of Toronto, Toronto, Ontario, Canada
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8
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Pachen M, Abukar Y, Shanks J, Lever N, Ramchandra R. Regulation of Coronary Blood Flow by the Carotid Body Chemoreceptors in Ovine Heart Failure. Front Physiol 2021; 12:681135. [PMID: 34122147 PMCID: PMC8195281 DOI: 10.3389/fphys.2021.681135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 04/26/2021] [Indexed: 11/17/2022] Open
Abstract
Carotid bodies (CBs) are peripheral chemoreceptors, which are primary sensors of systemic hypoxia and their activation produces respiratory, autonomic, and cardiovascular adjustments critical for body homeostasis. We have previously shown that carotid chemoreceptor stimulation increases directly recorded cardiac sympathetic nerve activity (cardiac SNA) which increases coronary blood flow (CoBF) in conscious normal sheep. Previous studies have shown that chemoreflex sensitivity is augmented in heart failure (HF). We hypothesized that carotid chemoreceptor stimulation would increase CoBF to a greater extent in HF than control sheep. Experiments were conducted in conscious HF sheep and control sheep (n = 6/group) implanted with electrodes to record diaphragmatic electromyography (dEMG), flow probes to record CoBF as well as arterial pressure. There was a significant increase in mean arterial pressure (MAP), CoBF and coronary vascular conductance (CVC) in response to potassium cyanide (KCN) in both groups of sheep. To eliminate the effects of metabolic vasodilation, the KCN was repeated while the heart was paced at a constant level. In this paradigm, the increase in CoBF and CVC was augmented in the HF group compared to the control group. Pre-treatment with propranolol did not alter the CoBF or the CVC increase in the HF group indicating this was not mediated by an increase in cardiac sympathetic drive. The pressor response to CB activation was abolished by pre-treatment with intravenous atropine in both groups, but there was no change in the CoBF and vascular conductance responses. Our data suggest that in an ovine model of HF, carotid body (CB) mediated increases in CoBF and CVC are augmented compared to control animals. This increase in CoBF is mediated by an increase in cardiac SNA in the control group but not the HF group.
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Affiliation(s)
- Mridula Pachen
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Yonis Abukar
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Julia Shanks
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Nigel Lever
- Department of Medicine, University of Auckland and Green Lane Cardiovascular Service, Auckland City Hospital, Auckland, New Zealand
| | - Rohit Ramchandra
- Department of Physiology, University of Auckland, Auckland, New Zealand
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9
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Pius-Sadowska E, Machaliński B. Pleiotropic activity of nerve growth factor in regulating cardiac functions and counteracting pathogenesis. ESC Heart Fail 2021; 8:974-987. [PMID: 33465292 PMCID: PMC8006610 DOI: 10.1002/ehf2.13138] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 11/05/2020] [Accepted: 11/11/2020] [Indexed: 12/30/2022] Open
Abstract
Cardiac innervation density generally reflects the levels of nerve growth factor (NGF) produced by the heart—changes in NGF expression within the heart and vasculature contribute to neuronal remodelling (e.g. sympathetic hyperinnervation or denervation). Its synthesis and release are altered under different pathological conditions. Although NGF is well known for its survival effects on neurons, it is clear that these effects are more wide ranging. Recent studies reported both in vitro and in vivo evidence for beneficial actions of NGF on cardiomyocytes in normal and pathological hearts, including prosurvival and antiapoptotic effects. NGF also plays an important role in the crosstalk between the nervous and cardiovascular systems. It was the first neurotrophin to be implicated in postnatal angiogenesis and vasculogenesis by autocrine and paracrine mechanisms. In connection with these unique cardiovascular properties of NGF, we have provided comprehensive insight into its function and potential effect of NGF underlying heart sustainable/failure conditions. This review aims to summarize the recent data on the effects of NGF on various cardiovascular neuronal and non‐neuronal functions. Understanding these mechanisms with respect to the diversity of NGF functions may be crucial for developing novel therapeutic strategies, including NGF action mechanism‐guided therapies.
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Affiliation(s)
- Ewa Pius-Sadowska
- Department of General Pathology, Pomeranian Medical University, Powstańców Wlkp. 72, Szczecin, 70111, Poland
| | - Bogusław Machaliński
- Department of General Pathology, Pomeranian Medical University, Powstańców Wlkp. 72, Szczecin, 70111, Poland
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10
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Tedoldi A, Argent L, Montgomery JM. The role of the tripartite synapse in the heart: how glial cells may contribute to the physiology and pathophysiology of the intracardiac nervous system. Am J Physiol Cell Physiol 2020; 320:C1-C14. [PMID: 33085497 DOI: 10.1152/ajpcell.00363.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
One of the major roles of the intracardiac nervous system (ICNS) is to act as the final site of signal integration for efferent information destined for the myocardium to enable local control of heart rate and rhythm. Multiple subtypes of neurons exist in the ICNS where they are organized into clusters termed ganglionated plexi (GP). The majority of cells in the ICNS are actually glial cells; however, despite this, ICNS glial cells have received little attention to date. In the central nervous system, where glial cell function has been widely studied, glia are no longer viewed simply as supportive cells but rather have been shown to play an active role in modulating neuronal excitability and synaptic plasticity. Pioneering studies have demonstrated that in addition to glia within the brain stem, glial cells within multiple autonomic ganglia in the peripheral nervous system, including the ICNS, can also act to modulate cardiovascular function. Clinically, patients with atrial fibrillation (AF) undergoing catheter ablation show high plasma levels of S100B, a protein produced by cardiac glial cells, correlated with decreased AF recurrence. Interestingly, S100B also alters GP neuron excitability and neurite outgrowth in the ICNS. These studies highlight the importance of understanding how glial cells can affect the heart by modulating GP neuron activity or synaptic inputs. Here, we review studies investigating glia both in the central and peripheral nervous systems to discuss the potential role of glia in controlling cardiac function in health and disease, paying particular attention to the glial cells of the ICNS.
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Affiliation(s)
- Angelo Tedoldi
- Department of Physiology, University of Auckland, Auckland, New Zealand.,Manaaki Mānawa Centre for Heart Research, University of Auckland, Auckland, New Zealand
| | - Liam Argent
- Department of Physiology, University of Auckland, Auckland, New Zealand.,Manaaki Mānawa Centre for Heart Research, University of Auckland, Auckland, New Zealand
| | - Johanna M Montgomery
- Department of Physiology, University of Auckland, Auckland, New Zealand.,Manaaki Mānawa Centre for Heart Research, University of Auckland, Auckland, New Zealand
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11
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Dyavanapalli J. Novel approaches to restore parasympathetic activity to the heart in cardiorespiratory diseases. Am J Physiol Heart Circ Physiol 2020; 319:H1153-H1161. [PMID: 33035444 DOI: 10.1152/ajpheart.00398.2020] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Neural control of the heart is regulated by sympathetic and parasympathetic divisions of the autonomic nervous system, both opposing each other to maintain cardiac homeostasis via regulating heart rate, conduction velocity, force of contraction, and coronary blood flow. Sympathetic hyperactivity and diminished parasympathetic activity are the characteristic features of many cardiovascular disease states including hypertension, myocardial ischemia, and arrhythmias that result in heart failure. Restoring parasympathetic activity to the heart has recently been identified as the promising approach to treat such conditions. However, approaches that used vagal nerve stimulation have been shown to be unsuccessful in heart failure. This review focuses on novel chemogenetic approaches used to identify the cardioprotective nature of activating neural points along the vagal pathway (both central and peripheral) while being selectively therapeutic in heart failure and obstructive sleep apnea.
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Affiliation(s)
- Jhansi Dyavanapalli
- Department of Pharmacology and Physiology, George Washington University, Washington, District of Columbia
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12
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Sobowale CO, Hori Y, Ajijola OA. Neuromodulation Therapy in Heart Failure: Combined Use of Drugs and Devices. J Innov Card Rhythm Manag 2020; 11:4151-4159. [PMID: 32724706 PMCID: PMC7377644 DOI: 10.19102/icrm.2020.110705] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 05/20/2020] [Indexed: 12/11/2022] Open
Abstract
Heart failure (HF) is the fastest-growing cardiovascular disease globally. The autonomic nervous system plays an important role in the regulation and homeostasis of cardiac function but, once there is HF, it takes on a detrimental role in cardiac function that makes it a rational target. In this review, we cover the remodeling of the autonomic nervous system in HF and the latest treatments available targeting it.
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Affiliation(s)
- Christopher O Sobowale
- UCLA Cardiac Arrhythmia Center, UCLA Neurocardiology Research Center, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Yuichi Hori
- UCLA Cardiac Arrhythmia Center, UCLA Neurocardiology Research Center, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.,Department of Cardiology, Dokkyo Medical University Saitama Medical Center, Saitama, Japan
| | - Olujimi A Ajijola
- UCLA Cardiac Arrhythmia Center, UCLA Neurocardiology Research Center, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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13
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Ashton JL, Argent L, Smith JEG, Jin S, Sands GB, Smaill BH, Montgomery JM. Evidence of structural and functional plasticity occurring within the intracardiac nervous system of spontaneously hypertensive rats. Am J Physiol Heart Circ Physiol 2020; 318:H1387-H1400. [DOI: 10.1152/ajpheart.00020.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
We have developed intracardiac neuron whole cell recording techniques in atrial preparations from control and spontaneous hypertensive rats. This has enabled the identification of significant synaptic plasticity in the intracardiac nervous system, including enhanced postsynaptic current frequency, increased synaptic terminal density, and altered postsynaptic receptors. This increased synaptic drive together with altered cardiac neuron electrophysiology could increase intracardiac nervous system excitability and contribute to the substrate for atrial arrhythmia in hypertensive heart disease.
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Affiliation(s)
- Jesse L. Ashton
- Department of Physiology, Manaaki Mānawa Centre for Heart Research, University of Auckland, Auckland, New Zealand
| | - Liam Argent
- Department of Physiology, Manaaki Mānawa Centre for Heart Research, University of Auckland, Auckland, New Zealand
| | - Joscelin E. G. Smith
- Department of Physiology, Manaaki Mānawa Centre for Heart Research, University of Auckland, Auckland, New Zealand
| | - Sangjun Jin
- Department of Physiology, Manaaki Mānawa Centre for Heart Research, University of Auckland, Auckland, New Zealand
| | - Gregory B. Sands
- Department of Physiology, Manaaki Mānawa Centre for Heart Research, University of Auckland, Auckland, New Zealand
- Bioengineering Institute, Manaaki Mānawa Centre for Heart Research, University of Auckland, Auckland, New Zealand
| | - Bruce H. Smaill
- Department of Physiology, Manaaki Mānawa Centre for Heart Research, University of Auckland, Auckland, New Zealand
- Bioengineering Institute, Manaaki Mānawa Centre for Heart Research, University of Auckland, Auckland, New Zealand
| | - Johanna M. Montgomery
- Department of Physiology, Manaaki Mānawa Centre for Heart Research, University of Auckland, Auckland, New Zealand
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14
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Dyavanapalli J, Hora AJ, Escobar JB, Schloen J, Dwyer MK, Rodriguez J, Spurney CF, Kay MW, Mendelowitz D. Chemogenetic activation of intracardiac cholinergic neurons improves cardiac function in pressure overload-induced heart failure. Am J Physiol Heart Circ Physiol 2020; 319:H3-H12. [PMID: 32412778 DOI: 10.1152/ajpheart.00150.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Heart failure (HF) is characterized by autonomic imbalance with sympathetic hyperactivity and loss of parasympathetic tone. Intracardiac ganglia (ICG) neurons represent the final common pathway for vagal innervation of the heart and strongly regulate cardiac functions. This study tests whether ICG cholinergic neuron activation mitigates the progression of cardiac dysfunction and reduces mortality that occurs in HF. HF was induced by transaortic constriction (TAC) in male transgenic Long-Evans rats expressing Cre recombinase within choline acetyltransferase (ChAT) neurons. ChAT neurons were selectively activated by expression and activation of excitatory designer receptors exclusively activated by designer receptors (DREADDs) by clozapine-N-oxide (TAC + treatment and sham-treated groups). Control animals expressed DREADDs but received saline (sham and TAC groups). A separate set of animals were telemetry instrumented to record blood pressure (BP) and heart rate (HR). Acute activation of ICG neurons resulted in robust reductions in BP (∼20 mmHg) and HR (∼100 beats/min). All groups of animals were subjected to weekly echocardiography and treadmill stress tests from 3 to 6 wk post-TAC/sham surgery. Activation of ICG cholinergic neurons reduced the left ventricular systolic dysfunction (reductions in ejection fraction, fractional shortening, stroke volume, and cardiac output) and cardiac autonomic dysfunction [reduced HR recovery (HRR) post peak effort] observed in TAC animals. Additionally, activation of ICG ChAT neurons reduced mortality by 30% compared with untreated TAC animals. These data suggest that ICG cholinergic neuron activation reduces cardiac dysfunction and improves survival in HF, indicating that ICG neuron activation could be a novel target for treating HF.NEW & NOTEWORTHY Intracardiac ganglia form the final common pathway for the parasympathetic innervation of the heart. This study has used a novel chemogenetic approach within transgenic ChAT-Cre rats [expressing only Cre-recombinase in choline acetyl transferase (ChAT) neurons] to selectively increase intracardiac cholinergic parasympathetic activity to the heart in a pressure overload-induced heart failure model. The findings from this study confirm that selective activation of intracardiac cholinergic neurons lessens cardiac dysfunction and mortality seen in heart failure, identifying a novel downstream cardiac-selective target for increasing cardioprotective parasympathetic activity in heart failure.
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Affiliation(s)
- Jhansi Dyavanapalli
- Department of Pharmacology and Physiology, George Washington University, Washington, District of Columbia
| | - Aloysius James Hora
- Department of Pharmacology and Physiology, George Washington University, Washington, District of Columbia
| | - Joan B Escobar
- Department of Pharmacology and Physiology, George Washington University, Washington, District of Columbia
| | - John Schloen
- Department of Biomedical Engineering, George Washington University, Washington, District of Columbia
| | - Mary Kate Dwyer
- Department of Biomedical Engineering, George Washington University, Washington, District of Columbia
| | - Jeannette Rodriguez
- Department of Biomedical Engineering, George Washington University, Washington, District of Columbia
| | - Christopher F Spurney
- Children's National Heart Institute, Center for Genetic Medicine Research, Children's National Health System, Washington, District of Columbia
| | - Matthew W Kay
- Department of Biomedical Engineering, George Washington University, Washington, District of Columbia
| | - David Mendelowitz
- Department of Pharmacology and Physiology, George Washington University, Washington, District of Columbia
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15
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Radcliffe EJ, Pearman CM, Watkins A, Lawless M, Kirkwood GJ, Saxton SN, Eisner DA, Trafford AW. Chronic vagal nerve stimulation has no effect on tachycardia-induced heart failure progression or excitation-contraction coupling. Physiol Rep 2020; 8:e14321. [PMID: 31961064 PMCID: PMC6971309 DOI: 10.14814/phy2.14321] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 11/25/2019] [Accepted: 11/28/2019] [Indexed: 12/13/2022] Open
Abstract
Autonomic dysregulation plays a key role in the development and progression of heart failure (HF). Vagal nerve stimulation (VNS) may be a promising therapeutic approach. However, the outcomes from clinical trials evaluating VNS in HF have been mixed, and the mechanisms underlying this treatment remain poorly understood. Intermittent high-frequency VNS (pulse width 300 µs, 30 Hz stimulation, 30 s on, and 300 s off) was used in healthy sheep and sheep in which established HF had been induced by 4 weeks rapid ventricular pacing to assess (a) the effects of VNS on intrinsic cardiac vagal tone, (b) whether VNS delays the progression of established HF, and (c) whether high-frequency VNS affects the regulation of cardiomyocyte calcium handling in health and disease. VNS had no effect on resting heart rate or intrinsic vagal tone in the healthy heart. Although fewer VNS-treated animals showed subjective signs of heart failure at 6 weeks, overall VNS did not slow the progression of clinical or echocardiographic signs of HF. Chronic VNS did not affect left ventricular cardiomyocyte calcium handling in healthy sheep. Rapid ventricular pacing decreased the L-type calcium current and calcium transient amplitude, but chronic VNS did not rescue dysfunctional calcium handling. Overall, high-frequency VNS did not prevent progression of established HF or influence cellular excitation-contraction coupling. However, a different model of HF or selection of different stimulation parameters may have yielded different results. These results highlight the need for greater insight into VNS dosing and parameter selection and a deeper understanding of its physiological effects.
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Affiliation(s)
- Emma J. Radcliffe
- Unit of Cardiac PhysiologyInstitute of Cardiovascular SciencesManchester Academic Health Sciences CentreThe University of ManchesterManchesterUK
| | - Charles M. Pearman
- Unit of Cardiac PhysiologyInstitute of Cardiovascular SciencesManchester Academic Health Sciences CentreThe University of ManchesterManchesterUK
| | - Amy Watkins
- Unit of Cardiac PhysiologyInstitute of Cardiovascular SciencesManchester Academic Health Sciences CentreThe University of ManchesterManchesterUK
| | - Michael Lawless
- Unit of Cardiac PhysiologyInstitute of Cardiovascular SciencesManchester Academic Health Sciences CentreThe University of ManchesterManchesterUK
| | - Graeme J. Kirkwood
- Unit of Cardiac PhysiologyInstitute of Cardiovascular SciencesManchester Academic Health Sciences CentreThe University of ManchesterManchesterUK
| | - Sophie N. Saxton
- Unit of Cardiac PhysiologyInstitute of Cardiovascular SciencesManchester Academic Health Sciences CentreThe University of ManchesterManchesterUK
| | - David A. Eisner
- Unit of Cardiac PhysiologyInstitute of Cardiovascular SciencesManchester Academic Health Sciences CentreThe University of ManchesterManchesterUK
| | - Andrew W. Trafford
- Unit of Cardiac PhysiologyInstitute of Cardiovascular SciencesManchester Academic Health Sciences CentreThe University of ManchesterManchesterUK
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16
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Abukar Y, Lever N, Pachen M, LeGrice IJ, Ramchandra R. Impaired Baroreflex Function in an Ovine Model of Chronic Heart Failure Induced by Multiple Coronary Microembolizations. Front Physiol 2019; 10:1420. [PMID: 31824334 PMCID: PMC6882935 DOI: 10.3389/fphys.2019.01420] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 11/04/2019] [Indexed: 12/12/2022] Open
Abstract
Testing new therapies in heart failure (HF) requires a chronic stable model of HF in large animals. Microembolization of the coronary arteries has been used to model HF previously; however, neural control has not been previously explored in this model. Thus the aim of this study was to further characterize neural control in this model of HF. HF was induced by infusion of microspheres (45 micron; 1.3 ml) into the proximal left coronary artery or left descending coronary arteries, with three sequential embolizations over 3 weeks. Twelve to 14 weeks after the final embolization, and when ejection fraction had decreased below 45%, animals were instrumented to record blood pressure and heart rate. Baroreflex control of heart rate was investigated in conscious animals. Additionally, pressure-volume loops were constructed under anesthesia. Embolization-induced HF was associated with a decrease in mean arterial pressure (67 ± 2 vs. 85 ± 4 mmHg, p < 0.05), an increase in heart rate (108 ± 4 vs. 94 ± 4 bpm, p < 0.05), and a significant increase in left ventricular end-diastolic pressure (11.4 ± 2 vs. 6.2 ± 1 mmHg, p < 0.01). Under conscious conditions, there was a significant decrease in the gain (-8.2 ± 2 vs. -4.1 ± 1 beats/min/mmHg, p < 0.05) as well as the lower plateau of the baroreflex in HF compared to control animals. HF was also associated with significantly increased respiratory rate (107 ± 4 vs. 87 ± 4 breaths/min, p < 0.01) and incidence of apneas (520 ± 24 vs. 191 ± 8 apnea periods >4 s, p < 0.05), compared to control sheep. The microembolization model of heart failure is associated with an increase in left ventricular end-diastolic pressure, impaired cardiac function, and altered baroreflex control of the heart. These findings suggest this chronic model of HF is appropriate to use for investigating interventions aimed at improving neural control in HF.
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Affiliation(s)
- Yonis Abukar
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Nigel Lever
- Department of Cardiology, Auckland District Health Board, Auckland, New Zealand
| | - Mridula Pachen
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Ian J LeGrice
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Rohit Ramchandra
- Department of Physiology, University of Auckland, Auckland, New Zealand
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17
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Ashton JL, Burton RAB, Bub G, Smaill BH, Montgomery JM. Synaptic Plasticity in Cardiac Innervation and Its Potential Role in Atrial Fibrillation. Front Physiol 2018; 9:240. [PMID: 29615932 PMCID: PMC5869186 DOI: 10.3389/fphys.2018.00240] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 03/06/2018] [Indexed: 12/30/2022] Open
Abstract
Synaptic plasticity is defined as the ability of synapses to change their strength of transmission. Plasticity of synaptic connections in the brain is a major focus of neuroscience research, as it is the primary mechanism underpinning learning and memory. Beyond the brain however, plasticity in peripheral neurons is less well understood, particularly in the neurons innervating the heart. The atria receive rich innervation from the autonomic branch of the peripheral nervous system. Sympathetic neurons are clustered in stellate and cervical ganglia alongside the spinal cord and extend fibers to the heart directly innervating the myocardium. These neurons are major drivers of hyperactive sympathetic activity observed in heart disease, ventricular arrhythmias, and sudden cardiac death. Both pre- and postsynaptic changes have been observed to occur at synapses formed by sympathetic ganglion neurons, suggesting that plasticity at sympathetic neuro-cardiac synapses is a major contributor to arrhythmias. Less is known about the plasticity in parasympathetic neurons located in clusters on the heart surface. These neuronal clusters, termed ganglionated plexi, or “little brains,” can independently modulate neural control of the heart and stimulation that enhances their excitability can induce arrhythmia such as atrial fibrillation. The ability of these neurons to alter parasympathetic activity suggests that plasticity may indeed occur at the synapses formed on and by ganglionated plexi neurons. Such changes may not only fine-tune autonomic innervation of the heart, but could also be a source of maladaptive plasticity during atrial fibrillation.
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Affiliation(s)
- Jesse L Ashton
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | | | - Gil Bub
- Department of Physiology, McGill University, Montreal, QC, Canada
| | - Bruce H Smaill
- Department of Physiology, University of Auckland, Auckland, New Zealand.,Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
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18
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van Bilsen M, Patel HC, Bauersachs J, Böhm M, Borggrefe M, Brutsaert D, Coats AJS, de Boer RA, de Keulenaer GW, Filippatos GS, Floras J, Grassi G, Jankowska EA, Kornet L, Lunde IG, Maack C, Mahfoud F, Pollesello P, Ponikowski P, Ruschitzka F, Sabbah HN, Schultz HD, Seferovic P, Slart RHJA, Taggart P, Tocchetti CG, Van Laake LW, Zannad F, Heymans S, Lyon AR. The autonomic nervous system as a therapeutic target in heart failure: a scientific position statement from the Translational Research Committee of the Heart Failure Association of the European Society of Cardiology. Eur J Heart Fail 2017; 19:1361-1378. [PMID: 28949064 DOI: 10.1002/ejhf.921] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 04/23/2017] [Accepted: 05/24/2017] [Indexed: 12/20/2022] Open
Abstract
Despite improvements in medical therapy and device-based treatment, heart failure (HF) continues to impose enormous burdens on patients and health care systems worldwide. Alterations in autonomic nervous system (ANS) activity contribute to cardiac disease progression, and the recent development of invasive techniques and electrical stimulation devices has opened new avenues for specific targeting of the sympathetic and parasympathetic branches of the ANS. The Heart Failure Association of the European Society of Cardiology recently organized an expert workshop which brought together clinicians, trialists and basic scientists to discuss the ANS as a therapeutic target in HF. The questions addressed were: (i) What are the abnormalities of ANS in HF patients? (ii) What methods are available to measure autonomic dysfunction? (iii) What therapeutic interventions are available to target the ANS in patients with HF, and what are their specific strengths and weaknesses? (iv) What have we learned from previous ANS trials? (v) How should we proceed in the future?
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Affiliation(s)
- Marc van Bilsen
- Department of Cardiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Hospital, Maastricht, the Netherlands
| | - Hitesh C Patel
- National Institute for Health Research (NIHR) Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK.,National Heart and Lung Institute, Imperial College London, London, UK.,Baker Heart and Diabetes Institute, Melbourne, Vic, Australia
| | - Johann Bauersachs
- Department of Cardiology and Angiology, Medical School Hannover, Hannover, Germany
| | - Michael Böhm
- Clinic for Internal Medicine III, Cardiology, Angiology and Intensive Internal Medicine, Homburg, Germany
| | - Martin Borggrefe
- First Department of Medicine, Cardiology Division, University Medical Centre Mannheim, Mannheim, Germany.,German Centre for Cardiovascular Research, Mannheim, Germany
| | - Dirk Brutsaert
- Department of Cardiology, Antwerp University, Antwerp, Belgium
| | - Andrew J S Coats
- Department of Medicine, Monash University, Melbourne, Vic, Australia.,Department of Medicine, University of Warwick, Coventry, UK
| | - Rudolf A de Boer
- Department of Cardiology, University Medical Centre Groningen, University of Groningen, Groningen, the Netherlands
| | | | - Gerasimos S Filippatos
- Department of Cardiology, School of Medicine, National and Kapodistrian University of Athens, Athens University Hospital Attikon, Athens, Greece
| | - John Floras
- University Health Network and Sinai Health System Division of Cardiology, Peter Munk Cardiac Centre, Toronto General and Lunenfeld-Tanenbaum Research Institutes, University of Toronto, Toronto, ON, Canada
| | - Guido Grassi
- Clinica Medica, Department of Medicine and Surgery, University of Milan-Bicocca, Milan, Italy.,IRCCS Multimedica, Milan, Italy
| | - Ewa A Jankowska
- Department of Heart Diseases, Wroclaw Medical University, Wroclaw, Poland.,Centre for Heart Diseases, Military Hospital, Wroclaw, Poland
| | - Lilian Kornet
- Medtronic, Inc., Bakken Research Centre, Maastricht, the Netherlands
| | - Ida G Lunde
- Institute for Experimental Medical Research, Oslo University Hospital, University of Oslo, Oslo, Norway
| | - Christoph Maack
- Clinic for Internal Medicine III, Cardiology, Angiology and Intensive Internal Medicine, Homburg, Germany
| | - Felix Mahfoud
- Clinic for Internal Medicine III, Cardiology, Angiology and Intensive Internal Medicine, Homburg, Germany
| | | | - Piotr Ponikowski
- Department of Heart Diseases, Wroclaw Medical University, Wroclaw, Poland.,Centre for Heart Diseases, Military Hospital, Wroclaw, Poland
| | - Frank Ruschitzka
- University Heart Centre, University Hospital Zurich, Zurich, Switzerland
| | - Hani N Sabbah
- Department of Medicine, Division of Cardiovascular Medicine, Henry Ford Hospital, Detroit, MI, USA
| | - Harold D Schultz
- Department of Cellular and Integrative Physiology, University of Nebraska College of Medicine, Omaha, NE, USA
| | - Petar Seferovic
- Department of Cardiology, Belgrade University Medical Centre, Belgrade, Serbia
| | - Riemer H J A Slart
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Centre Groningen, Groningen, the Netherlands.,Department of Biomedical Photonic Imaging, Faculty of Science and Technology, University of Twente, Enschede, the Netherlands
| | - Peter Taggart
- Department of Cardiovascular Science, University College London, Barts Heart Centre, London, UK
| | - Carlo G Tocchetti
- Department of Translational Medical Sciences, Federico II University, Naples, Italy
| | - Linda W Van Laake
- Department of Cardiology, Heart and Lungs Division, and Regenerative Medicine Centre, University Medical Centre Utrecht, Utrecht, the Netherlands
| | - Faiez Zannad
- INSERM, Centre for Clinical Investigation 9501, Unit 961, University Hospital Centre, Nancy, France.,Department of Cardiology, Nancy University, University of the Lorraine, Nancy, France
| | - Stephane Heymans
- Netherlands Heart Institute, Utrecht, the Netherlands.,Department of Cardiovascular Sciences, Leuven University, Leuven, Belgium
| | - Alexander R Lyon
- National Institute for Health Research (NIHR) Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK.,National Heart and Lung Institute, Imperial College London, London, UK
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19
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Ichige MHA, Pereira MG, Brum PC, Michelini LC. Experimental Evidences Supporting the Benefits of Exercise Training in Heart Failure. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 999:181-206. [PMID: 29022264 DOI: 10.1007/978-981-10-4307-9_11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Heart Failure (HF), a common end point for many cardiovascular diseases, is a syndrome with a very poor prognosis. Although clinical trials in HF have achieved important outcomes in reducing mortality, little is known about functional mechanisms conditioning health improvement in HF patients. In parallel with clinical studies, basic science has been providing important discoveries to understand the mechanisms underlying the pathophysiology of HF, as well as to identify potential targets for the treatment of this syndrome. In spite of being the end-point of cardiovascular derangements caused by different etiologies, autonomic dysfunction, sympathetic hyperactivity, oxidative stress, inflammation and hormonal activation are common factors involved in the progression of this syndrome. Together these causal factors create a closed link between three important organs: brain, heart and the skeletal muscle. In the past few years, we and other groups have studied the beneficial effects of aerobic exercise training as a safe therapy to avoid the progression of HF. As summarized in this chapter, exercise training, a non-pharmacological tool without side effects, corrects most of the HF-induced neurohormonal and local dysfunctions within the brain, heart and skeletal muscles. These adaptive responses reverse oxidative stress, reduce inflammation, ameliorate neurohormonal control and improve both cardiovascular and skeletal muscle function, thus increasing the quality of life and reducing patients' morbimortality.
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Affiliation(s)
- Marcelo H A Ichige
- Department of Physiology & Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Marcelo G Pereira
- Department of Biodynamics of Human Body Movement, School of Physical Education and Sport, University of Sao Paulo, Sao Paulo, Brazil
| | - Patrícia C Brum
- Department of Biodynamics of Human Body Movement, School of Physical Education and Sport, University of Sao Paulo, Sao Paulo, Brazil. .,National Institute for Science & Technology - INCT (In)activity & Exercise, CNPq - Niterói (RJ), Rio de Janeiro, Brazil.
| | - Lisete C Michelini
- Department of Physiology & Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil.,National Institute for Science & Technology - INCT (In)activity & Exercise, CNPq - Niterói (RJ), Rio de Janeiro, Brazil
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20
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Ichige MHA, Santos CR, Jordão CP, Ceroni A, Negrão CE, Michelini LC. Exercise training preserves vagal preganglionic neurones and restores parasympathetic tonus in heart failure. J Physiol 2016; 594:6241-6254. [PMID: 27444212 PMCID: PMC5088253 DOI: 10.1113/jp272730] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 07/08/2016] [Indexed: 01/01/2023] Open
Abstract
KEY POINTS Heart Failure (HF) is accompanied by reduced ventricular function, activation of compensatory neurohormonal mechanisms and marked autonomic dysfunction characterized by exaggerated sympathoexcitation and reduced parasympathetic activity. With 6 weeks of exercise training, HF-related loss of choline acetyltransferase (ChAT)-positive vagal preganglionic neurones is avoided, restoring the parasympathetic tonus to the heart, and the immunoreactivity of dopamine β-hydroxylase-positive premotor neurones that drive sympathetic outflow to the heart is reduced. Training-induced correction of autonomic dysfunction occurs even with the persistence of abnormal ventricular function. Strong positive correlation between improved parasympathetic tonus to the heart and increased ChAT immunoreactivity in vagal preganglionic neurones after training indicates this is a crucial mechanism to restore autonomic function in heart failure. ABSTRACT Exercise training is an efficient tool to attenuate sympathoexcitation, a hallmark of heart failure (HF). Although sympathetic modulation in HF is widely studied, information regarding parasympathetic control is lacking. We examined the combined effects of sympathetic and vagal tonus to the heart in sedentary (Sed) and exercise trained (ET) HF rats and the contribution of respective premotor and preganglionic neurones. Wistar rats submitted to coronary artery ligation or sham surgery were assigned to training or sedentary protocols for 6 weeks. After haemodynamic, autonomic tonus (atropine and atenolol i.v.) and ventricular function determinations, brains were collected for immunoreactivity assays (choline acetyltransferase, ChATir; dopamine β-hydroxylase, DBHir) and neuronal counting in the dorsal motor nucleus of vagus (DMV), nucleus ambiguus (NA) and rostroventrolateral medulla (RVLM). HF-Sed vs. SHAM-Sed exhibited decreased exercise capacity, reduced ejection fraction, increased left ventricle end diastolic pressure, smaller positive and negative dP/dt, decreased intrinsic heart rate (IHR), lower parasympathetic and higher sympathetic tonus, reduced preganglionic vagal neurones and ChATir in the DMV/NA, and increased RVLM DBHir. Training increased treadmill performance, normalized autonomic tonus and IHR, restored the number of DMV and NA neurones and corrected ChATir without affecting ventricular function. There were strong positive correlations between parasympathetic tonus and ChATir in NA and DMV. RVLM DBHir was also normalized by training, but there was no change in neurone number and no correlation with sympathetic tonus. Training-induced preservation of preganglionic vagal neurones is crucial to normalize parasympathetic activity and restore autonomic balance to the heart even in the persistence of cardiac dysfunction.
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Affiliation(s)
- Marcelo H A Ichige
- Department of Physiology and Biophysics, Biomedical Sciences Institute, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Carla R Santos
- Department of Physiology and Biophysics, Biomedical Sciences Institute, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Camila P Jordão
- Heart Institute, University of Sao Paulo, Medical School, Sao Paulo, SP, Brazil
| | - Alexandre Ceroni
- Department of Physiology and Biophysics, Biomedical Sciences Institute, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Carlos E Negrão
- Heart Institute, University of Sao Paulo, Medical School, Sao Paulo, SP, Brazil
- School of Physical Education and Sport, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Lisete C Michelini
- Department of Physiology and Biophysics, Biomedical Sciences Institute, University of Sao Paulo, Sao Paulo, SP, Brazil.
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21
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Delfiner MS, Siano J, Li Y, Dedkov EI, Zhang Y. Reduced epicardial vagal nerve density and impaired vagal control in a rat myocardial infarction-heart failure model. Cardiovasc Pathol 2016; 26:21-29. [PMID: 27852001 DOI: 10.1016/j.carpath.2016.10.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 10/07/2016] [Accepted: 10/17/2016] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Autonomic remodeling, characterized by sympathetic activation and vagal withdrawal, contributes to heart failure (HF) progression. However, the exact mechanism(s) responsible for vagal withdrawal in HF remain(s) unclear, and whether HF causes epicardial autonomic nerve remodeling is unknown. METHODS AND RESULTS Myocardial infarction (MI) was produced in 14 Sprague-Dawley rats, and 10 sham surgery rats served as the control. MI-HF was confirmed 2 months after the surgery by echocardiography and hemodynamic measurement. Cervical vagal nerve stimulation was delivered to examine the heart rate slowing effect. Whole heart acetylcholinesterase histochemistry was used to examine the epicardial autonomic nerve remodeling at dorsal ventricles (remote from the infarcted area). Compared with the control animals, the same vagal nerve stimulation had less heart rate slowing effect in MI-HF group. Both epicardial nerve bundle length-density (2.56±0.60 μm/mm2 versus 1.68±0.46 μm/mm2, P=.001) and branching point-density (1.24±0.25 points/mm2 versus 0.66±0.18 points/mm2, P<.001) were lower in MI-HF rats. The chemically stained epicardial nerve bundles contain both sympathetic (tyrosine hydroxylase positive) and vagal (choline acetyltransferase positive) fibers. However, within the stained nerve bundle, the chemical color corresponds mainly with the vagal fibers. CONCLUSIONS Whole heart acetylcholinesterase histochemistry revealed a decreased ventricular epicardial vagal nerve density in MI-HF rats, which may contribute to impaired cardiac vagal control in HF.
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Affiliation(s)
- Matthew S Delfiner
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY, USA
| | - John Siano
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY, USA
| | - Ying Li
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY, USA
| | - Eduard I Dedkov
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY, USA
| | - Youhua Zhang
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY, USA.
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22
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Smith FM, Vermeulen M, Cardinal R. Long-term spinal cord stimulation modifies canine intrinsic cardiac neuronal properties and ganglionic transmission during high-frequency repetitive activation. Physiol Rep 2016; 4:4/13/e12855. [PMID: 27401459 PMCID: PMC4945838 DOI: 10.14814/phy2.12855] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 06/16/2016] [Indexed: 12/28/2022] Open
Abstract
Long‐term spinal cord stimulation (SCS) applied to cranial thoracic SC segments exerts antiarrhythmic and cardioprotective actions in the canine heart in situ. We hypothesized that remodeling of intrinsic cardiac neuronal and synaptic properties occur in canines subjected to long‐term SCS, specifically that synaptic efficacy may be preferentially facilitated at high presynaptic nerve stimulation frequencies. Animals subjected to continuous SCS for 5–8 weeks (long‐term SCS: n = 17) or for 1 h (acute SCS: n = 4) were compared with corresponding control animals (long‐term: n = 15, acute: n = 4). At termination, animals were anesthetized, the heart was excised and neurones from the right atrial ganglionated plexus were identified and studied in vitro using standard intracellular microelectrode technique. Main findings were as follows: (1) a significant reduction in whole cell membrane input resistance and acceleration of the course of AHP decay identified among phasic neurones from long‐term SCS compared with controls, (2) significantly more robust synaptic transmission to rundown in long‐term SCS during high‐frequency (10–40 Hz) presynaptic nerve stimulation while recording from either phasic or accommodating postsynaptic neurones; this was associated with significantly greater posttrain excitatory postsynaptic potential (EPSP) numbers in long‐term SCS than control, and (3) synaptic efficacy was significantly decreased by atropine in both groups. Such changes did not occur in acute SCS. In conclusion, modification of intrinsic cardiac neuronal properties and facilitation of synaptic transmission at high stimulation frequency in long‐term SCS could improve physiologically modulated vagal inputs to the heart.
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Affiliation(s)
- Frank M Smith
- Department of Medical Neuroscience, Faculty of Medicine Dalhousie University, Halifax, Nova Scotia, Canada
| | - Michel Vermeulen
- Department of Pharmacology, Faculté de médecine Université de Montréal and Centre de recherche Hôpital du Sacré-Cœur de Montréal, Montréal, Quebec, Canada
| | - René Cardinal
- Department of Pharmacology, Faculté de médecine Université de Montréal and Centre de recherche Hôpital du Sacré-Cœur de Montréal, Montréal, Quebec, Canada
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23
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Ho HT, Belevych AE, Liu B, Bonilla IM, Radwański PB, Kubasov IV, Valdivia HH, Schober K, Carnes CA, Györke S. Muscarinic Stimulation Facilitates Sarcoplasmic Reticulum Ca Release by Modulating Ryanodine Receptor 2 Phosphorylation Through Protein Kinase G and Ca/Calmodulin-Dependent Protein Kinase II. Hypertension 2016; 68:1171-1178. [PMID: 27647848 DOI: 10.1161/hypertensionaha.116.07666] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Accepted: 08/21/2016] [Indexed: 01/01/2023]
Abstract
Although the effects and the underlying mechanism of sympathetic stimulation on cardiac Ca handling are relatively well established both in health and disease, the modes of action and mechanisms of parasympathetic modulation are poorly defined. Here, we demonstrate that parasympathetic stimulation initiates a novel mode of excitation-contraction coupling that enhances the efficiency of cardiac sarcoplasmic reticulum Ca store utilization. This efficient mode of excitation-contraction coupling involves reciprocal changes in the phosphorylation of ryanodine receptor 2 at Ser-2808 and Ser-2814. Specifically, Ser-2808 phosphorylation was mediated by muscarinic receptor subtype 2 and activation of PKG (protein kinase G), whereas dephosphorylation of Ser-2814 involved activation of muscarinic receptor subtype 3 and decreased reactive oxygen species-dependent activation of CaMKII (Ca/calmodulin-dependent protein kinase II). The overall effect of these changes in phosphorylation of ryanodine receptor 2 is an increase in systolic Ca release at the low sarcoplasmic reticulum Ca content and a paradoxical reduction in aberrant Ca leak. Accordingly, cholinergic stimulation of cardiomyocytes isolated from failing hearts improved Ca cycling efficiency by restoring altered ryanodine receptor 2 phosphorylation balance.
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Affiliation(s)
- Hsiang-Ting Ho
- From the Department of Physiology and Cell Biology (H.-T.H., A.E.B., B.L., P.B.R., S.G.), College of Pharmacy (I.M.B., P.B.R., C.A.C.), and College of Veterinary Medicine (K.S.), The Ohio State University, Columbus; Davis Heart and Lung Research Institute, Columbus, OH (H.-T.H., A.E.B., B.L., I.M.B., P.B.R., C.A.C., S.G.); Department of Medicine, Duke University, Durham, NC (H.-T.H.); Laboratory of Neuromuscular Physiology, I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Petersburg, Russia (I.V.K.); and Center for Arrhythmia Research, Cardiovascular Division of the Department of Internal Medicine, University of Michigan, Ann Arbor (H.H.V.)
| | - Andriy E Belevych
- From the Department of Physiology and Cell Biology (H.-T.H., A.E.B., B.L., P.B.R., S.G.), College of Pharmacy (I.M.B., P.B.R., C.A.C.), and College of Veterinary Medicine (K.S.), The Ohio State University, Columbus; Davis Heart and Lung Research Institute, Columbus, OH (H.-T.H., A.E.B., B.L., I.M.B., P.B.R., C.A.C., S.G.); Department of Medicine, Duke University, Durham, NC (H.-T.H.); Laboratory of Neuromuscular Physiology, I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Petersburg, Russia (I.V.K.); and Center for Arrhythmia Research, Cardiovascular Division of the Department of Internal Medicine, University of Michigan, Ann Arbor (H.H.V.)
| | - Bin Liu
- From the Department of Physiology and Cell Biology (H.-T.H., A.E.B., B.L., P.B.R., S.G.), College of Pharmacy (I.M.B., P.B.R., C.A.C.), and College of Veterinary Medicine (K.S.), The Ohio State University, Columbus; Davis Heart and Lung Research Institute, Columbus, OH (H.-T.H., A.E.B., B.L., I.M.B., P.B.R., C.A.C., S.G.); Department of Medicine, Duke University, Durham, NC (H.-T.H.); Laboratory of Neuromuscular Physiology, I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Petersburg, Russia (I.V.K.); and Center for Arrhythmia Research, Cardiovascular Division of the Department of Internal Medicine, University of Michigan, Ann Arbor (H.H.V.)
| | - Ingrid M Bonilla
- From the Department of Physiology and Cell Biology (H.-T.H., A.E.B., B.L., P.B.R., S.G.), College of Pharmacy (I.M.B., P.B.R., C.A.C.), and College of Veterinary Medicine (K.S.), The Ohio State University, Columbus; Davis Heart and Lung Research Institute, Columbus, OH (H.-T.H., A.E.B., B.L., I.M.B., P.B.R., C.A.C., S.G.); Department of Medicine, Duke University, Durham, NC (H.-T.H.); Laboratory of Neuromuscular Physiology, I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Petersburg, Russia (I.V.K.); and Center for Arrhythmia Research, Cardiovascular Division of the Department of Internal Medicine, University of Michigan, Ann Arbor (H.H.V.)
| | - Przemysław B Radwański
- From the Department of Physiology and Cell Biology (H.-T.H., A.E.B., B.L., P.B.R., S.G.), College of Pharmacy (I.M.B., P.B.R., C.A.C.), and College of Veterinary Medicine (K.S.), The Ohio State University, Columbus; Davis Heart and Lung Research Institute, Columbus, OH (H.-T.H., A.E.B., B.L., I.M.B., P.B.R., C.A.C., S.G.); Department of Medicine, Duke University, Durham, NC (H.-T.H.); Laboratory of Neuromuscular Physiology, I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Petersburg, Russia (I.V.K.); and Center for Arrhythmia Research, Cardiovascular Division of the Department of Internal Medicine, University of Michigan, Ann Arbor (H.H.V.)
| | - Igor V Kubasov
- From the Department of Physiology and Cell Biology (H.-T.H., A.E.B., B.L., P.B.R., S.G.), College of Pharmacy (I.M.B., P.B.R., C.A.C.), and College of Veterinary Medicine (K.S.), The Ohio State University, Columbus; Davis Heart and Lung Research Institute, Columbus, OH (H.-T.H., A.E.B., B.L., I.M.B., P.B.R., C.A.C., S.G.); Department of Medicine, Duke University, Durham, NC (H.-T.H.); Laboratory of Neuromuscular Physiology, I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Petersburg, Russia (I.V.K.); and Center for Arrhythmia Research, Cardiovascular Division of the Department of Internal Medicine, University of Michigan, Ann Arbor (H.H.V.)
| | - Héctor H Valdivia
- From the Department of Physiology and Cell Biology (H.-T.H., A.E.B., B.L., P.B.R., S.G.), College of Pharmacy (I.M.B., P.B.R., C.A.C.), and College of Veterinary Medicine (K.S.), The Ohio State University, Columbus; Davis Heart and Lung Research Institute, Columbus, OH (H.-T.H., A.E.B., B.L., I.M.B., P.B.R., C.A.C., S.G.); Department of Medicine, Duke University, Durham, NC (H.-T.H.); Laboratory of Neuromuscular Physiology, I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Petersburg, Russia (I.V.K.); and Center for Arrhythmia Research, Cardiovascular Division of the Department of Internal Medicine, University of Michigan, Ann Arbor (H.H.V.)
| | - Karsten Schober
- From the Department of Physiology and Cell Biology (H.-T.H., A.E.B., B.L., P.B.R., S.G.), College of Pharmacy (I.M.B., P.B.R., C.A.C.), and College of Veterinary Medicine (K.S.), The Ohio State University, Columbus; Davis Heart and Lung Research Institute, Columbus, OH (H.-T.H., A.E.B., B.L., I.M.B., P.B.R., C.A.C., S.G.); Department of Medicine, Duke University, Durham, NC (H.-T.H.); Laboratory of Neuromuscular Physiology, I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Petersburg, Russia (I.V.K.); and Center for Arrhythmia Research, Cardiovascular Division of the Department of Internal Medicine, University of Michigan, Ann Arbor (H.H.V.)
| | - Cynthia A Carnes
- From the Department of Physiology and Cell Biology (H.-T.H., A.E.B., B.L., P.B.R., S.G.), College of Pharmacy (I.M.B., P.B.R., C.A.C.), and College of Veterinary Medicine (K.S.), The Ohio State University, Columbus; Davis Heart and Lung Research Institute, Columbus, OH (H.-T.H., A.E.B., B.L., I.M.B., P.B.R., C.A.C., S.G.); Department of Medicine, Duke University, Durham, NC (H.-T.H.); Laboratory of Neuromuscular Physiology, I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Petersburg, Russia (I.V.K.); and Center for Arrhythmia Research, Cardiovascular Division of the Department of Internal Medicine, University of Michigan, Ann Arbor (H.H.V.)
| | - Sándor Györke
- From the Department of Physiology and Cell Biology (H.-T.H., A.E.B., B.L., P.B.R., S.G.), College of Pharmacy (I.M.B., P.B.R., C.A.C.), and College of Veterinary Medicine (K.S.), The Ohio State University, Columbus; Davis Heart and Lung Research Institute, Columbus, OH (H.-T.H., A.E.B., B.L., I.M.B., P.B.R., C.A.C., S.G.); Department of Medicine, Duke University, Durham, NC (H.-T.H.); Laboratory of Neuromuscular Physiology, I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Petersburg, Russia (I.V.K.); and Center for Arrhythmia Research, Cardiovascular Division of the Department of Internal Medicine, University of Michigan, Ann Arbor (H.H.V.).
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24
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Abstract
Cardiac control is mediated via a series of reflex control networks involving somata in the (i) intrinsic cardiac ganglia (heart), (ii) intrathoracic extracardiac ganglia (stellate, middle cervical), (iii) superior cervical ganglia, (iv) spinal cord, (v) brainstem, and (vi) higher centers. Each of these processing centers contains afferent, efferent, and local circuit neurons, which interact locally and in an interdependent fashion with the other levels to coordinate regional cardiac electrical and mechanical indices on a beat-to-beat basis. This control system is optimized to respond to normal physiological stressors (standing, exercise, and temperature); however, it can be catastrophically disrupted by pathological events such as myocardial ischemia. In fact, it is now recognized that autonomic dysregulation is central to the evolution of heart failure and arrhythmias. Autonomic regulation therapy is an emerging modality in the management of acute and chronic cardiac pathologies. Neuromodulation-based approaches that target select nexus points of this hierarchy for cardiac control offer unique opportunities to positively affect therapeutic outcomes via improved efficacy of cardiovascular reflex control. As such, understanding the anatomical and physiological basis for such control is necessary to implement effectively novel neuromodulation therapies. © 2016 American Physiological Society. Compr Physiol 6:1635-1653, 2016.
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Affiliation(s)
- Jeffrey L Ardell
- Los Angeles (UCLA) Cardiac Arrhythmia Center, David Geffen School of Medicine, University of California, Los Angeles, California, USA.,UCLA Neurocardiology Research Center of Excellence, David Geffen School of Medicine, Los Angeles, California, USA
| | - John Andrew Armour
- Los Angeles (UCLA) Cardiac Arrhythmia Center, David Geffen School of Medicine, University of California, Los Angeles, California, USA.,UCLA Neurocardiology Research Center of Excellence, David Geffen School of Medicine, Los Angeles, California, USA
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25
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Ardell JL, Andresen MC, Armour JA, Billman GE, Chen PS, Foreman RD, Herring N, O'Leary DS, Sabbah HN, Schultz HD, Sunagawa K, Zucker IH. Translational neurocardiology: preclinical models and cardioneural integrative aspects. J Physiol 2016; 594:3877-909. [PMID: 27098459 DOI: 10.1113/jp271869] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 03/14/2016] [Indexed: 12/15/2022] Open
Abstract
Neuronal elements distributed throughout the cardiac nervous system, from the level of the insular cortex to the intrinsic cardiac nervous system, are in constant communication with one another to ensure that cardiac output matches the dynamic process of regional blood flow demand. Neural elements in their various 'levels' become differentially recruited in the transduction of sensory inputs arising from the heart, major vessels, other visceral organs and somatic structures to optimize neuronal coordination of regional cardiac function. This White Paper will review the relevant aspects of the structural and functional organization for autonomic control of the heart in normal conditions, how these systems remodel/adapt during cardiac disease, and finally how such knowledge can be leveraged in the evolving realm of autonomic regulation therapy for cardiac therapeutics.
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Affiliation(s)
- J L Ardell
- University of California - Los Angeles (UCLA) Cardiac Arrhythmia Center, David Geffen School of Medicine, Los Angeles, CA, USA.,UCLA Neurocardiology Research Center of Excellence, David Geffen School of Medicine, Los Angeles, CA, USA
| | - M C Andresen
- Department of Physiology and Pharmacology, Oregon Health and Science University, Portland, OR, USA
| | - J A Armour
- University of California - Los Angeles (UCLA) Cardiac Arrhythmia Center, David Geffen School of Medicine, Los Angeles, CA, USA.,UCLA Neurocardiology Research Center of Excellence, David Geffen School of Medicine, Los Angeles, CA, USA
| | - G E Billman
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA
| | - P-S Chen
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - R D Foreman
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - N Herring
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - D S O'Leary
- Department of Physiology, Wayne State University, Detroit, MI, USA
| | - H N Sabbah
- Department of Medicine, Henry Ford Hospital, Detroit, MI, USA
| | - H D Schultz
- Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - K Sunagawa
- Department of Cardiovascular Medicine, Kyushu University, Fukuoka, Japan
| | - I H Zucker
- Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, USA
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26
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Pinto TOCT, Lataro RM, Castania JA, Durand MT, Silva CAA, Patel KP, Fazan R, Salgado HC. Electrical stimulation of the aortic depressor nerve in conscious rats overcomes the attenuation of the baroreflex in chronic heart failure. Am J Physiol Regul Integr Comp Physiol 2016; 310:R612-8. [DOI: 10.1152/ajpregu.00392.2015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 01/14/2016] [Indexed: 11/22/2022]
Abstract
Chronic heart failure (CHF) is characterized by autonomic dysfunction combined with baroreflex attenuation. The hypotensive and bradycardic responses produced by electrical stimulation of the aortic depressor nerve (ADN) were examined in conscious CHF and control male Wistar rats (12–13 wk old). Furthermore, the role of parasympathetic and sympathetic nervous system in mediating the cardiovascular responses to baroreflex activation was evaluated by selective β1-adrenergic and muscarinic receptor antagonists. CHF was induced by myocardial infarction. After 6 wk, the subjects were implanted with electrodes for ADN stimulation. Twenty-four hours later, electrical stimulation of the ADN was applied for 20 s using five different frequencies (5, 15, 30, 60, and 90 Hz), while the arterial pressure was recorded by a catheter implanted into the femoral artery. Electrical stimulation of the ADN elicited progressive and similar hypotensive and bradycardic responses in control ( n = 12) and CHF ( n = 11) rats, while the hypotensive response was not affected by methylatropine. Nevertheless, the reflex bradycardia was attenuated by methylatropine in control, but not in CHF rats. Atenolol did not affect the hypotensive or bradycardic response in either group. The ADN function was examined under anesthesia through electroneurographic recordings. The arterial pressure-ADN activity relationship was attenuated in CHF rats. In conclusion, despite the attenuation of baroreceptor function in CHF rats, the electrical stimulation of the ADN elicited a stimulus-dependent hypotension and bradycardia of similar magnitude as observed in control rats. Therefore, electrical activation of the aortic baroreflex overcomes both the attenuation of parasympathetic function and the sympathetic overdrive.
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Affiliation(s)
- Tomás O. C. Teixeira Pinto
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Renata M. Lataro
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Jaci A. Castania
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Marina T. Durand
- Department of Medicine, University of Ribeirão Preto, Ribeirão Preto, São Paulo, Brazil; and
| | - Carlos A. A. Silva
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Kaushik P. Patel
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska
| | - Rubens Fazan
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Helio C. Salgado
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
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27
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O'Callaghan EL, Chauhan AS, Zhao L, Lataro RM, Salgado HC, Nogaret A, Paton JFR. Utility of a Novel Biofeedback Device for Within-Breath Modulation of Heart Rate in Rats: A Quantitative Comparison of Vagus Nerve vs. Right Atrial Pacing. Front Physiol 2016; 7:27. [PMID: 26869940 PMCID: PMC4740386 DOI: 10.3389/fphys.2016.00027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 01/18/2016] [Indexed: 12/04/2022] Open
Abstract
In an emerging bioelectronics era, there is a clinical need for physiological devices incorporating biofeedback that permits natural and demand-dependent control in real time. Here, we describe a novel device termed a central pattern generator (CPG) that uses cutting edge analog circuitry producing temporally controlled, electrical stimulus outputs based on the real time integration of physiological feedback. Motivated by the fact that respiratory sinus arrhythmia (RSA), which is the cyclical changes in heart rate every breath, is an essential component of heart rate variability (HRV) (an indicator of cardiac health), we have explored the versatility and efficiency of the CPG for producing respiratory modulation of heart rate in anesthetized, spontaneously breathing rats. Diaphragmatic electromyographic activity was used as the input to the device and its output connected to either the right cervical vagus nerve or the right atrium for pacing heart rate. We found that the CPG could induce respiratory related heart rate modulation that closely mimicked RSA. Whether connected to the vagus nerve or right atrium, the versatility of the device was demonstrated by permitting: (i) heart rate modulation in any phase of the respiratory cycle, (ii) control of the magnitude of heart rate modulation, and (iii) instant adaptation to changes in respiratory frequency. Vagal nerve pacing was only possible following transection of the nerve limiting its effective use chronically. Pacing via the right atrium permitted better flexibility and control of heart rate above its intrinsic level. This investigation now lays the foundation for future studies using this biofeedback technology permitting closer analysis of both the function and dysfunction of RSA.
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Affiliation(s)
- Erin L O'Callaghan
- School of Physiology, Pharmacology and Neuroscience, University of Bristol Bristol, UK
| | | | - Le Zhao
- Department of Physics, University of Bath Bath, UK
| | - Renata M Lataro
- School of Physiology, Pharmacology and Neuroscience, University of BristolBristol, UK; Department of Physiology, School of Medicine of Ribeirão Preto, University of São PauloSão Paulo, Brazil
| | - Helio C Salgado
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo São Paulo, Brazil
| | | | - Julian F R Paton
- School of Physiology, Pharmacology and Neuroscience, University of Bristol Bristol, UK
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28
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Hartnett S, Gao H, Schnack S, Li Y. Reduced vagal control of the heart in high-fat diet mice: a potential role of increased butyrylcholinesterase. Physiol Rep 2015; 3:3/11/e12609. [PMID: 26537347 PMCID: PMC4673638 DOI: 10.14814/phy2.12609] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Suppressed parasympathetic function is commonly present in cardiovascular diseases, aging, obesity, and various other health conditions. Impaired parasympathetic action is known as a detrimental factor and contributes to the adverse outcomes in these conditions. However, the underlying mechanisms remain to be fully addressed. In this study, using high-fat diet (HFD)-induced obese mice as a model, the potential peripheral mechanisms underlying the impaired parasympathetic vagal control of the heart was examined. The HFD induced obesity and metabolic disorder in mice. These obese mice exhibited an attenuated response in heart rate to vagal stimulation, indicating impairment of peripheral parasympathetic activity in the heart. In cholinergic function-related proteins in the atria, protein levels of choline transporter and vesicular acetylcholine transporter were not decreased but increased, and type 2 muscarinic receptors showed a trend toward a reduction in HFD mice atria as compared with regular diet (RD) mice controls. While the protein level of acetylcholinesterase was not different, butyrylcholinesterase (BChE) protein level showed a twofold increase in HFD mice atria as compared with RD mice. Functionally, inhibition of BChE activity partially and significantly improved the attenuated response in heart rate to vagal stimulation in HFD mice. Collectively, these data suggest that increased BChE activity in the atria may contribute to the decreased parasympathetic function in HFD-induced obese mice.
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Affiliation(s)
- Sigurd Hartnett
- Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, South Dakota
| | - Hongbo Gao
- Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, South Dakota
| | - Sabrina Schnack
- Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, South Dakota
| | - Yifan Li
- Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, South Dakota
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29
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Abstract
OPINION STATEMENT Despite major advances that have led to effective therapeutic modalities for the treatment of heart failure (HF), this syndrome has continued to be a staggering health problem associated with significant mortality and morbidity. The increasing number of hospital admissions and readmissions related to acute HF continues to pose a fiscal challenge leading to constant interest in development of novel approaches. These point to multiple areas of unmet needs especially in acute HF, thus, necessitating further efforts to develop novel strategies for prevention and treatment of acute HF. One area of continuing focus is targeting the role of autonomic imbalance associated with the development of HF. Autonomic dysregulation, manifested by increased sympathetic drive and reduced parasympathetic activity, has been recognized as a mediator of increased mortality and morbidity in HF and myocardial infarction. Furthermore, vagal withdrawal has been shown to precede acute decompensation, though whether this represents cause or effect is unknown. This review discusses the potential role of autonomic dysregulation as a therapeutic modality for patients with acute decompensated HF.
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30
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Floras JS, Ponikowski P. The sympathetic/parasympathetic imbalance in heart failure with reduced ejection fraction. Eur Heart J 2015; 36:1974-82b. [PMID: 25975657 DOI: 10.1093/eurheartj/ehv087] [Citation(s) in RCA: 168] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 03/06/2015] [Indexed: 12/20/2022] Open
Abstract
Cardiovascular autonomic imbalance, a cardinal phenotype of human heart failure, has adverse implications for symptoms during wakefulness and sleep; for cardiac, renal, and immune function; for exercise capacity; and for lifespan and mode of death. The objectives of this Clinical Review are to summarize current knowledge concerning mechanisms for disturbed parasympathetic and sympathetic circulatory control in heart failure with reduced ejection fraction and its clinical and prognostic implications; to demonstrate the patient-specific nature of abnormalities underlying this common phenotype; and to illustrate how such variation provides opportunities to improve or restore normal sympathetic/parasympathetic balance through personalized drug or device therapy.
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Affiliation(s)
- John S Floras
- University Health Network and Mount Sinai Hospital Division of Cardiology, University of Toronto, Suite 1614, 600 University Avenue, Toronto, Ontario, Canada M5G 1X5
| | - Piotr Ponikowski
- Department for Heart Disease, Medical University, Clinical Military Hospital, Wroclaw, Poland
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31
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Innovative devices for advanced heart failure: exploring the current state and future direction of device therapies. Curr Opin Cardiol 2015; 30:267-76. [PMID: 25807225 DOI: 10.1097/hco.0000000000000169] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE OF REVIEW Despite improvements in medical and device therapies for the treatment of heart failure, the incidence and prevalence of heart failure continue to increase. Given the relative stagnation in new pharmacologic therapies, considerable attention has been given in recent years to device therapies to supplement care in patients with advanced heart failure. Recent successful clinical trial results with an angiotensin-neprilysin inhibitor are not expected to change this situation significantly; the drug has been shown to delay, not eliminate, the progression of heart failure. This review focuses on the technologies that are currently in development for the treatment of advanced heart failure. RECENT FINDINGS Novel devices that involve electrical, neurohormonal or structural remodeling of the heart that can be inserted either percutaneously or with a minimally invasive surgery are currently at various stages of clinical development. All, however, have shown promising clinical results in preclinical and early clinical studies. SUMMARY Novel device therapies for advanced heart failure continue to show promising clinical results. Randomized controlled trials are still needed to better evaluate their efficacy. Nevertheless, it can be anticipated that at least several of these devices will be among the armamentarium of treatment options for advanced heart failure in the future.
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32
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Moss E, Cardinal R, Yin Y, Pagé P. Biatrial neuroablation attenuates atrial remodeling and vulnerability to atrial fibrillation in canine chronic rapid atrial pacing. Auton Neurosci 2015; 189:43-9. [PMID: 25746009 DOI: 10.1016/j.autneu.2015.02.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 12/24/2014] [Accepted: 02/17/2015] [Indexed: 11/26/2022]
Abstract
AIMS We investigated the proposition that an intact cardiac nervous system may contribute to electrophysiological remodeling and increased vulnerability to atrial fibrillation (AF) following chronic rapid atrial pacing (RAP). METHODS AND RESULTS Baseline study was conducted prior to ablating right and left ganglionated plexuses (RAGP, LAGP) in 11 anesthetized canines (Neuroablation group) and in 11 canines without neuroablation (Intact GP). After being subjected to RAP (400 beats/min) for 6 weeks, animals were reanesthetized for terminal study. The ERP shortening typical of chronic RAP was significantly more pronounced in the Intact GP (baseline: 112 ± 12 to terminal: 80 ± 11 ms) than in the Neuroablation group (113 ± 18 to 102 ± 21 ms, p < .001), and AF inducibility (extrastimulus protocol) showed significantly greater increment in the Intact GP (baseline: 23 ± 19% to terminal: 60 ± 17% of trials) than in the Neuroablation group (18 ± 15% to 27 ± 17%, p = 0.029). Negative chronotropic responses to right vagus nerve stimulation were markedly reduced immediately after the neuroablation procedure but had recovered at terminal study. Vagally-evoked repolarization changes (from 191 unipolar electrograms) occurred in a majority of Intact GP animals in the superior, middle and inferior RA free wall, and in the LA appendage. In the Neuroablation group, repolarization changes were restricted to the superior RA free wall but none occurred in the inferior RA and only infrequently in the LA appendage, yielding significantly smaller affected areas in Neuroablation than in Intact GP animals. CONCLUSION Persistent functional denervation in LA and RA regions other than RA pacemaker areas may contribute to prevent the development of a tachycardia-dependent AF substrate.
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Affiliation(s)
- Emmanuel Moss
- Centre de recherche, Hôpital du Sacré-Cœur de Montréal, Montréal, Canada; Department of Surgery, Université de Montréal, Montreal, Canada
| | - René Cardinal
- Centre de recherche, Hôpital du Sacré-Cœur de Montréal, Montréal, Canada; Department of Pharmacology, Université de Montréal, Montreal, Canada
| | - Yalin Yin
- Centre de recherche, Hôpital du Sacré-Cœur de Montréal, Montréal, Canada
| | - Pierre Pagé
- Centre de recherche, Hôpital du Sacré-Cœur de Montréal, Montréal, Canada; Department of Surgery, Université de Montréal, Montreal, Canada.
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33
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Nogaret A, O'Callaghan EL, Lataro RM, Salgado HC, Meliza CD, Duncan E, Abarbanel HDI, Paton JFR. Silicon central pattern generators for cardiac diseases. J Physiol 2015; 593:763-74. [PMID: 25433077 DOI: 10.1113/jphysiol.2014.282723] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 11/16/2014] [Indexed: 11/08/2022] Open
Abstract
Cardiac rhythm management devices provide therapies for both arrhythmias and resynchronisation but not heart failure, which affects millions of patients worldwide. This paper reviews recent advances in biophysics and mathematical engineering that provide a novel technological platform for addressing heart disease and enabling beat-to-beat adaptation of cardiac pacing in response to physiological feedback. The technology consists of silicon hardware central pattern generators (hCPGs) that may be trained to emulate accurately the dynamical response of biological central pattern generators (bCPGs). We discuss the limitations of present CPGs and appraise the advantages of analog over digital circuits for application in bioelectronic medicine. To test the system, we have focused on the cardio-respiratory oscillators in the medulla oblongata that modulate heart rate in phase with respiration to induce respiratory sinus arrhythmia (RSA). We describe here a novel, scalable hCPG comprising physiologically realistic (Hodgkin-Huxley type) neurones and synapses. Our hCPG comprises two neurones that antagonise each other to provide rhythmic motor drive to the vagus nerve to slow the heart. We show how recent advances in modelling allow the motor output to adapt to physiological feedback such as respiration. In rats, we report on the restoration of RSA using an hCPG that receives diaphragmatic electromyography input and use it to stimulate the vagus nerve at specific time points of the respiratory cycle to slow the heart rate. We have validated the adaptation of stimulation to alterations in respiratory rate. We demonstrate that the hCPG is tuneable in terms of the depth and timing of the RSA relative to respiratory phase. These pioneering studies will now permit an analysis of the physiological role of RSA as well as its any potential therapeutic use in cardiac disease.
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Affiliation(s)
- Alain Nogaret
- Department of Physics, University of Bath, Bath, BA2 7AY, UK
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34
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Roy A, Guatimosim S, Prado VF, Gros R, Prado MAM. Cholinergic activity as a new target in diseases of the heart. Mol Med 2015; 20:527-37. [PMID: 25222914 DOI: 10.2119/molmed.2014.00125] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 09/09/2014] [Indexed: 12/21/2022] Open
Abstract
The autonomic nervous system is an important modulator of cardiac signaling in both health and disease. In fact, the significance of altered parasympathetic tone in cardiac disease has recently come to the forefront. Both neuronal and nonneuronal cholinergic signaling likely play a physiological role, since modulating acetylcholine (ACh) signaling from neurons or cardiomyocytes appears to have significant consequences in both health and disease. Notably, many of these effects are solely due to changes in cholinergic signaling, without altered sympathetic drive, which is known to have significant adverse effects in disease states. As such, it is likely that enhanced ACh-mediated signaling not only has direct positive effects on cardiomyocytes, but it also offsets the negative effects of hyperadrenergic tone. In this review, we discuss recent studies that implicate ACh as a major regulator of cardiac remodeling and provide support for the notion that enhancing cholinergic signaling in human patients with cardiac disease can reduce morbidity and mortality. These recent results support the idea of developing large clinical trials of strategies to increase cholinergic tone, either by stimulating the vagus or by increased availability of Ach, in heart failure.
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Affiliation(s)
- Ashbeel Roy
- Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada.,Department of Physiology and Pharmacology, The University of Western Ontario, London, Ontario, Canada
| | - Silvia Guatimosim
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Vania F Prado
- Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada.,Department of Physiology and Pharmacology, The University of Western Ontario, London, Ontario, Canada.,Department of Anatomy and Cell Biology, The University of Western Ontario, London, Ontario, Canada
| | - Robert Gros
- Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada.,Department of Physiology and Pharmacology, The University of Western Ontario, London, Ontario, Canada.,Department of Medicine, University of Western Ontario, London, Ontario, Canada
| | - Marco A M Prado
- Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada.,Department of Physiology and Pharmacology, The University of Western Ontario, London, Ontario, Canada.,Department of Anatomy and Cell Biology, The University of Western Ontario, London, Ontario, Canada
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35
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Brack KE. The heart's 'little brain' controlling cardiac function in the rabbit. Exp Physiol 2014; 100:348-53. [PMID: 25833107 PMCID: PMC4409095 DOI: 10.1113/expphysiol.2014.080168] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 09/19/2014] [Indexed: 12/31/2022]
Abstract
NEW FINDINGS What is the topic of this review? The topic of the review is the intrinsic cardiac nervous system in the rabbit. What advances does it highlight? The anatomy of rabbit intrinsic ganglia is similar to that of other species, including humans. Immunohistochemistry confirms the presence of cholinergic and adrenergic neurones, with a striking arrangement of neuronal nitric oxide synthase-positive cell bodies. Activation of atrial ganglia produces effects on local and remote regions. Heart disease is a primary cause of mortality in the developed world, and it is well recognized that neural mechanisms play an important role in many cardiac pathologies. The role of extrinsic autonomic nerves has traditionally attracted the most attention. However, there is a rich intrinsic innervation of the heart, including numerous cardiac ganglia (ganglionic plexuses), that has the potential to affect cardiac function independently as well as to influence the actions of the extrinsic nerves. To investigate this, an isolated, perfused, innervated rabbit Langendorff heart preparation was considered the best option. Although ganglionic plexuses have been well described for several species, there was no full description of the anatomy and histochemistry of rabbit hearts. To this end, rabbit intrinsic ganglia were located using acetylcholinesterase histology (n = 33 hearts). This revealed six generalized ganglionic regions, defined as a left neuronal complex above the left pulmonary vein, a right neuronal complex around the base of right cranial vein, three scattered in the dorsal right atrium and a region containing numerous ventricular ganglia located on the conus arteriosus. Using immunohistochemistry, neurons were found to contain choline acetyltransferase or tyrosine hydroxylase and/or neuronal nitric oxide synthase in differing amounts (choline acetyltransferase > tyrosine hydroxylase > neuronal nitric oxide synthase). The function of rabbit intrinsic ganglia was investigated using a bolus application of nicotine or electrical stimulation at each of the above sites whilst measuring heart rate and atrioventricular conduction. Nicotine applied to different ganglionic plexuses caused a bradycardia, a tachycardia or a mixture of the two, with the right atrial plexus producing the largest chronotropic responses. Electrical stimulation at these sites induced only a bradycardia. Atrioventricular conduction was modestly changed by nicotine, the main response being a prolongation. Electrical stimulation produced significant prolongation of atrioventricular conduction, particularly when the right neuronal complex was stimulated. These studies show that the intrinsic plexuses of the heart are important and could be crucial for understanding impairments of cardiac function. Additionally, they provide a strong basis from which to progress using the isolated, innervated rabbit heart preparation.
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Affiliation(s)
- Kieran E Brack
- Department of Cardiovascular Sciences, Cardiology Group, Glenfield Hospital, University of Leicester, UK; Leicester NIHR Biomedical Research Unit in Cardiovascular Disease, Glenfield Hospital, Leicester, UK
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Schwartz PJ. Can we Modulate the Autonomic Nervous System to Improve the Life of Patients with Heart Failure? The Case of Vagal Stimulation. Arrhythm Electrophysiol Rev 2014; 3:120-2. [PMID: 26835078 PMCID: PMC4711534 DOI: 10.15420/aer.2014.3.2.120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2014] [Accepted: 07/29/2014] [Indexed: 01/08/2023] Open
Abstract
An imbalance of the autonomic nervous system, with reduced vagal and increased sympathetic activity, contributes to pathogenesis and clinical deterioration in heart failure (HF). Experimental studies have demonstrated that vagal stimulation (VS) has an antifibrillatory effect that has proved beneficial in animal models of HF. The potential value of chronic VS in man was first investigated with an implantable neuro-stimulator capable of delivering low current pulses with adjustable parameters to stimulate the right vagus. The results of a pilot study and a small multicentre clinical trial of VS in HF patients appeared to show a favourable clinical effect, and feasibility and safety data were encouraging. An ongoing pivotal clinical trial will provide a definitive assessment of the efficacy and usefulness of chronic VS in HF patients.This approach represents a new and exciting possibility for the management of HF that will provide clinicians with a novel tool to modulate non-pharmacologically the autonomic nervous system in patients with moderate-to-advanced HF.
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Affiliation(s)
- Peter J Schwartz
- Professor and Head, Centre for Cardiac Arrhythmias of Genetic Origin, IRCCS Istituto Auxologico Italiano, Milan, Italy
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Mechanisms underlying the autonomic modulation of ventricular fibrillation initiation--tentative prophylactic properties of vagus nerve stimulation on malignant arrhythmias in heart failure. Heart Fail Rev 2014; 18:389-408. [PMID: 22678767 PMCID: PMC3677978 DOI: 10.1007/s10741-012-9314-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Classical physiology teaches that vagal post-ganglionic nerves modulate the heart via acetylcholine acting at muscarinic receptors, whilst it is accepted that vagus nerve stimulation (VNS) slows heart rate, atrioventricular conduction and decreases atrial contraction; there is continued controversy as to whether the vagus has any significant direct effect on ventricular performance. Despite this, there is a significant body of evidence from experimental and clinical studies, demonstrating that the vagus nerve has an anti-arrhythmic action, protecting against induced and spontaneously occurring ventricular arrhythmias. Over 100 years ago Einbrodt first demonstrated that direct cervical VNS significantly increased the threshold for experimentally induced ventricular fibrillation. A large body of evidence has subsequently been collected supporting the existence of an anti-arrhythmic effect of the vagus on the ventricle. The development of prognostic indicators of heart rate variability and baroreceptor reflex sensitivity—measures of parasympathetic tone and reflex activation respectively—and the more recent interest in chronic VNS therapy are a direct consequence of the earlier experimental studies. Despite this, mechanisms underlying the anti-arrhythmic actions of the vagus nerve have not been fully characterised and are not well understood. This review summarises historical and recently published data to highlight the importance of this powerful endogenous protective phenomenon.
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Kuck KH, Bordachar P, Borggrefe M, Boriani G, Burri H, Leyva F, Schauerte P, Theuns D, Thibault B, Kirchhof P, Hasenfuss G, Dickstein K, Leclercq C, Linde C, Tavazzi L, Ruschitzka F. New devices in heart failure: an European Heart Rhythm Association report: Developed by the European Heart Rhythm Association; Endorsed by the Heart Failure Association. Europace 2013; 16:109-28. [DOI: 10.1093/europace/eut311] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Cuevas J. Molecular mechanisms of dysautonomia during heart failure. Focus on "Heart failure-induced changes of voltage-gated Ca2+ channels and cell excitability in rat cardiac postganglionic neurons". Am J Physiol Cell Physiol 2013; 306:C121-2. [PMID: 24108866 DOI: 10.1152/ajpcell.00311.2013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Javier Cuevas
- Department of Molecular Pharmacology and Physiology, College of Medicine, University of South Florida, Tampa, Florida
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Tomaszek A, Kiczak L, Bania J, Krupa P, Pasławska U, Zacharski M, Janiszewski A, Stefaniak T, Zyśko D, Ardehali H, Jankowska EA, Ponikowski P. Changes in parasympathetic system in medulla oblongata in male pigs in the course of tachycardia-induced cardiomyopathy. Auton Neurosci 2013; 177:253-9. [DOI: 10.1016/j.autneu.2013.05.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 04/30/2013] [Accepted: 05/20/2013] [Indexed: 01/14/2023]
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Tu H, Liu J, Zhang D, Zheng H, Patel KP, Cornish KG, Wang WZ, Muelleman RL, Li YL. Heart failure-induced changes of voltage-gated Ca2+ channels and cell excitability in rat cardiac postganglionic neurons. Am J Physiol Cell Physiol 2013; 306:C132-42. [PMID: 24025863 DOI: 10.1152/ajpcell.00223.2013] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Chronic heart failure (CHF) is characterized by decreased cardiac parasympathetic and increased cardiac sympathetic nerve activity. This autonomic imbalance increases the risk of arrhythmias and sudden death in patients with CHF. We hypothesized that the molecular and cellular alterations of cardiac postganglionic parasympathetic (CPP) neurons located in the intracardiac ganglia and sympathetic (CPS) neurons located in the stellate ganglia (SG) possibly link to the cardiac autonomic imbalance in CHF. Rat CHF was induced by left coronary artery ligation. Single-cell real-time PCR and immunofluorescent data showed that L (Ca(v)1.2 and Ca(v)1.3), P/Q (Ca(v)2.1), N (Ca(v)2.2), and R (Ca(v)2.3) types of Ca2+ channels were expressed in CPP and CPS neurons, but CHF decreased the mRNA and protein expression of only the N-type Ca2+ channels in CPP neurons, and it did not affect mRNA and protein expression of all Ca2+ channel subtypes in the CPS neurons. Patch-clamp recording confirmed that CHF reduced N-type Ca2+ currents and cell excitability in the CPP neurons and enhanced N-type Ca2+ currents and cell excitability in the CPS neurons. N-type Ca2+ channel blocker (1 μM ω-conotoxin GVIA) lowered Ca2+ currents and cell excitability in the CPP and CPS neurons from sham-operated and CHF rats. These results suggest that CHF reduces the N-type Ca2+ channel currents and cell excitability in the CPP neurons and enhances the N-type Ca2+ currents and cell excitability in the CPS neurons, which may contribute to the cardiac autonomic imbalance in CHF.
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Affiliation(s)
- Huiyin Tu
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, Nebraska
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Singh S, Sayers S, Walter JS, Thomas D, Dieter RS, Nee LM, Wurster RD. Hypertrophy of neurons within cardiac ganglia in human, canine, and rat heart failure: the potential role of nerve growth factor. J Am Heart Assoc 2013; 2:e000210. [PMID: 23959444 PMCID: PMC3828807 DOI: 10.1161/jaha.113.000210] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background Autonomic imbalances including parasympathetic withdrawal and sympathetic overactivity are cardinal features of heart failure regardless of etiology; however, mechanisms underlying these imbalances remain unknown. Animal model studies of heart and visceral organ hypertrophy predict that nerve growth factor levels should be elevated in heart failure; whether this is so in human heart failure, though, remains unclear. We tested the hypotheses that neurons in cardiac ganglia are hypertrophied in human, canine, and rat heart failure and that nerve growth factor, which we hypothesize is elevated in the failing heart, contributes to this neuronal hypertrophy. Methods and Results Somal morphology of neurons from human (579.54±14.34 versus 327.45±9.17 μm2; P<0.01) and canine hearts (767.80±18.37 versus 650.23±9.84 μm2; P<0.01) failing secondary to ischemia and neurons from spontaneously hypertensive rat hearts (327.98±3.15 versus 271.29±2.79 μm2; P<0.01) failing secondary to hypertension reveal significant hypertrophy of neurons in cardiac ganglia compared with controls. Western blot analysis shows that nerve growth factor levels in the explanted, failing human heart are 250% greater than levels in healthy donor hearts. Neurons from cardiac ganglia cultured with nerve growth factor are significantly larger and have greater dendritic arborization than neurons in control cultures. Conclusions Hypertrophied neurons are significantly less excitable than smaller ones; thus, hypertrophy of vagal postganglionic neurons in cardiac ganglia would help to explain the parasympathetic withdrawal that accompanies heart failure. Furthermore, our observations suggest that nerve growth factor, which is elevated in the failing human heart, causes hypertrophy of neurons in cardiac ganglia.
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Affiliation(s)
- Sanjay Singh
- Research Services, Hines VA Medical Center, Hines, IL
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Sabino JPJ, da Silva CAA, Giusti H, Glass ML, Salgado HC, Fazan R. Parasympathetic activation by pyridostigmine on chemoreflex sensitivity in heart-failure rats. Auton Neurosci 2013; 179:43-8. [PMID: 23911533 DOI: 10.1016/j.autneu.2013.07.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 07/02/2013] [Accepted: 07/03/2013] [Indexed: 10/26/2022]
Abstract
We evaluated the effects of parasympathetic activation by pyridostigmine (PYR) on chemoreflex sensitivity in a rat model of heart failure (HF rats). HF rats demonstrated higher pulmonary ventilation (PV), which was not affected by PYR. When HF and control rats treated or untreated with PYR were exposed to 15% O2, all groups exhibited prompt increases in respiratory frequency (RF), tidal volume (TV) and PV. When HF rats were exposed to 10% O2 they showed greater PV response which was prevented by PYR. The hypercapnia triggered by either 5% CO2 or 10% CO2 promoted greater RF and PV responses in HF rats. PYR blunted the RF response in HF rats but did not affect the PV response. In conclusion, PYR prevented increased peripheral chemoreflex sensitivity, partially blunted central chemoreflex sensitivity and did not affect basal PV in HF rats.
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Affiliation(s)
- João Paulo J Sabino
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
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Kawada T, Li M, Shimizu S, Kamiya A, Uemura K, Turner MJ, Mizuno M, Sugimachi M. High-frequency dominant depression of peripheral vagal control of heart rate in rats with chronic heart failure. Acta Physiol (Oxf) 2013; 207:494-502. [PMID: 23279751 DOI: 10.1111/apha.12055] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 12/02/2012] [Accepted: 12/15/2012] [Indexed: 12/13/2022]
Abstract
AIM To examine whether dynamic characteristics of the peripheral vagal control of heart rate (HR) are altered in chronic heart failure (CHF). METHODS The right vagal nerve was electrically stimulated according to a binary white noise signal, and the transfer function from vagal nerve stimulation (VNS) to HR was estimated in the frequency range from 0.01 to 1 Hz in five control rats and five CHF rats under anaesthetized conditions. The rate of VNS was changed among 10, 20 and 40 Hz. RESULTS A multiple linear regression analysis indicated that the increase in the VNS rate augmented the ratio of the high-frequency (HF) gain to the steady-state gain in the control group but not in the CHF group. As a result, the dynamic gain of the transfer function in the frequencies near 1 Hz decreased more in the CHF group than in the control group. CONCLUSION Changes in the dynamic characteristics of the peripheral vagal control of HR may contribute to the manifestation of decreased HF components of HR variability observed in CHF.
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Affiliation(s)
- T. Kawada
- Department of Cardiovascular Dynamics; National Cerebral and Cardiovascular Center; Osaka; Japan
| | - M. Li
- Department of Cardiovascular Dynamics; National Cerebral and Cardiovascular Center; Osaka; Japan
| | - S. Shimizu
- Department of Cardiovascular Dynamics; National Cerebral and Cardiovascular Center; Osaka; Japan
| | - A. Kamiya
- Department of Cardiovascular Dynamics; National Cerebral and Cardiovascular Center; Osaka; Japan
| | - K. Uemura
- Department of Cardiovascular Dynamics; National Cerebral and Cardiovascular Center; Osaka; Japan
| | - M. J. Turner
- Department of Cardiovascular Dynamics; National Cerebral and Cardiovascular Center; Osaka; Japan
| | - M. Mizuno
- Department of Health Care Sciences; University of Texas Southwestern Medical Center; Dallas; TX; USA
| | - M. Sugimachi
- Department of Cardiovascular Dynamics; National Cerebral and Cardiovascular Center; Osaka; Japan
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The treatment with pyridostigmine improves the cardiocirculatory function in rats with chronic heart failure. Auton Neurosci 2013; 173:58-64. [DOI: 10.1016/j.autneu.2012.11.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Revised: 10/26/2012] [Accepted: 11/12/2012] [Indexed: 11/24/2022]
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Zhang Y, Popović ZB, Kusunose K, Mazgalev TN. Therapeutic effects of selective atrioventricular node vagal stimulation in atrial fibrillation and heart failure. J Cardiovasc Electrophysiol 2012; 24:86-91. [PMID: 22913453 DOI: 10.1111/j.1540-8167.2012.02405.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Atrial fibrillation (AF) and heart failure (HF) frequently coexist. We have previously demonstrated that selective atrioventricular node (AVN) vagal stimulation (AVN-VS) can be used to control ventricular rate during AF. Due to withdrawal of vagal activity in HF, the therapeutic effects of AVN-VS may be compromised in the combined condition of AF and HF. Accordingly, this study was designed to evaluate the therapeutic effects of AVN-VS to control ventricular rate in AF and HF. METHODS AND RESULTS A combined model of AF and HF was created by implanting a dual chamber pacemaker in 24 dogs. A newly designed bipolar electrode was inserted into the ganglionic AVN fat pad and connected to a nerve stimulator for delivering AVN-VS. In all dogs, HF was induced by high rate ventricular pacing at 220 bpm for 4 weeks. AF was then induced and maintained by rapid atrial pacing at 600 bpm after discontinuation of ventricular pacing. These HF + AF dogs were randomized into control (n = 9) and AVN-VS (n = 15) groups. In the latter group, vagal stimulation (310 μs, 20 Hz, 3-7 mA) was delivered continuously for 6 months. Compared with the control, AVN-VS had a consistent effect on ventricular rate slowing (by >50 bpm, all P < 0.001) during the entire 6-month observation period that was associated with left ventricular functional improvement. Moreover, AVN-VS was well tolerated by the treated animals. CONCLUSIONS AVN-VS achieved consistent rate slowing, which was associated with improved ventricular function in a canine AF and HF model. Thus, AVN-VS may be a novel, effective therapeutic option in the combined condition of AF and HF.
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Affiliation(s)
- Youhua Zhang
- Department of Molecular Cardiology, The Cleveland Clinic, Cleveland, Ohio, USA.
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Notarius CF, Floras JS. Caffeine Enhances Heart Rate Variability in Middle-Aged Healthy, But Not Heart Failure Subjects. JOURNAL OF CAFFEINE RESEARCH 2012; 2:77-82. [PMID: 24761268 DOI: 10.1089/jcr.2012.0010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND In chronic heart failure (CHF) due to left ventricular dysfunction, diminished heart rate variability (HRV) is an independent predictor of poor prognosis. Caffeine has been shown to increase HRV in young healthy subjects. Such an increase may be of potential benefit to patients with CHF. OBJECTIVE We hypothesized that intravenous infusion of caffeine would increase HRV in CHF, and in age-matched healthy control subjects. METHODS On two separate days, 11 patients (1F) with CHF (age=51.3±4.6 years; left ventricular ejection fraction=18.6±2.7%; mean±standard error) and 10 healthy control subjects (age=48.0±4.0) according to a double-blind randomization design, received either saline or caffeine (4 mg/kg) infusion. We assessed HRV over 7 minutes of supine rest (fast Fourier Transform analysis) to determine total spectral power as well as its high-frequency (HF) (0.15-0.50 Hz) and low-frequency (LF) (0.05-0.15 Hz) components, and recorded muscle sympathetic nerve activity (MSNA) directly from the peroneal nerve (microneurography). RESULTS In healthy control subjects, compared with saline, caffeine reduced both heart rate and sympathetic nerve traffic (p≤0.003) and increased the ratio of HF/total power (p≤0.05). Baseline LF power and the ratio LF/HF were significantly lower in CHF compared with controls (p=0.02), but caffeine had no effect on any element of HRV. CONCLUSIONS Caffeine increases cardiac vagal heart rate modulation and reduces MSNA in middle-aged healthy subjects, but not in those with CHF.
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Affiliation(s)
- Catherine F Notarius
- Division of Cardiology, University Health Network and Mount Sinai Hospital, University of Toronto , Toronto, ON, Canada
| | - John S Floras
- Division of Cardiology, University Health Network and Mount Sinai Hospital, University of Toronto , Toronto, ON, Canada
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Cutler MJ, Kaufman ES. Breakdown of the integration center: right atrial ganglionated plexus dysfunction in heart failure. J Cardiovasc Electrophysiol 2011; 23:413-4. [PMID: 22081945 DOI: 10.1111/j.1540-8167.2011.02222.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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McAllen RM, Salo LM, Paton JFR, Pickering AE. Processing of central and reflex vagal drives by rat cardiac ganglion neurones: an intracellular analysis. J Physiol 2011; 589:5801-18. [PMID: 22005679 DOI: 10.1113/jphysiol.2011.214320] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Cardiac vagal tone is an important indicator of cardiovascular health, and its loss is an independent risk factor for arrhythmias and mortality. Several studies suggest that this loss of vagal tone can occur at the cardiac ganglion but the factors affecting ganglionic transmission in vivo are poorly understood. We have employed a novel approach allowing intracellular recordings from functionally connected cardiac vagal ganglion cells in the working heart-brainstem preparation. The atria were stabilised in situ preserving their central neural connections, and ganglion cells (n = 32) were impaled with sharp microelectrodes. Cardiac ganglion cells with vagal synaptic inputs (spontaneous, n = 10; or electrically evoked from the vagus, n = 3) were identified as principal neurones and showed tonic firing responses to current injected to their somata. Cells lacking vagal inputs (n = 19, presumed interneurones) were quiescent but showed phasic firing responses to depolarising current. In principal cells the ongoing action potentials and EPSPs exhibited respiratory modulation, with peak frequency in post-inspiration. Action potentials arose from unitary EPSPs and autocorrelation of those events showed that each ganglion cell received inputs from a single active preganglionic source. Peripheral chemoreceptor, arterial baroreceptor and diving response activation all evoked high frequency synaptic barrages in these cells, always from the same single preganglionic source. EPSP amplitudes showed frequency dependent depression, leading to more spike failures at shorter inter-event intervals. These findings indicate that rather than integrating convergent inputs, cardiac vagal postganglionic neurones gate preganglionic inputs, so regulating the proportion of central parasympathetic tone that is transmitted on to the heart.
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Affiliation(s)
- Robin M McAllen
- Florey Neuroscience Institutes and Department of Anatomy & Cell Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
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Abstract
Parasympathetic control of the heart via the vagus nerve is the primary mechanism that regulates beat-to-beat control of heart rate. Additionally, the vagus nerve exerts significant effects at the AV node, as well as effects on both atrial and ventricular myocardium. Vagal control is abnormal in heart failure, occurring at early stages of left ventricular dysfunction, and this reduced vagal function is associated with worse outcomes in patients following myocardial infarction and with heart failure. While central control mechanisms are abnormal, one of the primary sites of attenuated vagal control is at the level of the parasympathetic ganglion. It remains to be seen whether or not preventing or treating abnormal vagal control of the heart improves prognosis.
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Affiliation(s)
- Steve Bibevski
- Department of Cardiothoracic Surgery, University of Michigan Cardiovascular Center, 5144 Cardiovascular Center, 1500 E. Medical Center Drive SPC 5864, Ann Arbor, MI 48109, USA
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