51
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Ang R, Marina N. Low-Frequency Oscillations in Cardiac Sympathetic Neuronal Activity. Front Physiol 2020; 11:236. [PMID: 32256390 PMCID: PMC7093552 DOI: 10.3389/fphys.2020.00236] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 03/02/2020] [Indexed: 12/25/2022] Open
Abstract
Sudden cardiac death caused by ventricular arrhythmias is among the leading causes of mortality, with approximately half of all deaths attributed to heart disease worldwide. Periodic repolarization dynamics (PRD) is a novel marker of repolarization instability and strong predictor of death in patients post-myocardial infarction that is believed to occur in association with low-frequency oscillations in sympathetic nerve activity. However, this hypothesis is based on associations of PRD with indices of sympathetic activity that are not directly linked to cardiac function, such as muscle vasoconstrictor activity and the variability of cardiovascular autospectra. In this review article, we critically evaluate existing scientific evidence obtained primarily in experimental animal models, with the aim of identifying the neuronal networks responsible for the generation of low-frequency sympathetic rhythms along the neurocardiac axis. We discuss the functional significance of rhythmic sympathetic activity on neurotransmission efficacy and explore its role in the pathogenesis of ventricular repolarization instability. Most importantly, we discuss important gaps in our knowledge that require further investigation in order to confirm the hypothesis that low frequency cardiac sympathetic oscillations play a causative role in the generation of PRD.
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Affiliation(s)
- Richard Ang
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Nephtali Marina
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom.,Division of Medicine, University College London, London, United Kingdom
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52
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Verrier RL, Pang TD, Nearing BD, Schachter SC. The Epileptic Heart: Concept and clinical evidence. Epilepsy Behav 2020; 105:106946. [PMID: 32109857 DOI: 10.1016/j.yebeh.2020.106946] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 01/07/2020] [Accepted: 01/23/2020] [Indexed: 12/18/2022]
Abstract
Sudden unexpected death in epilepsy (SUDEP) is generally considered to result from a seizure, typically convulsive and usually but not always occurring during sleep, followed by a sequence of events in the postictal period starting with respiratory distress and progressing to eventual cardiac asystole and death. Yet, recent community-based studies indicate a 3-fold greater incidence of sudden cardiac death in patients with chronic epilepsy than in the general population, and that in 66% of cases, the cardiac arrest occurred during routine daily activity and without a temporal relationship with a typical seizure. To distinguish a primarily cardiac cause of death in patients with epilepsy from the above description of SUDEP, we propose the concept of the "Epileptic Heart" as "a heart and coronary vasculature damaged by chronic epilepsy as a result of repeated surges in catecholamines and hypoxemia leading to electrical and mechanical dysfunction." This review starts with an overview of the pathophysiological and other lines of evidence supporting the biological plausibility of the Epileptic Heart, followed by a description of tools that have been used to generate new electrocardiogram (EKG)-derived data in patients with epilepsy that strongly support the Epileptic Heart concept and its propensity to cause sudden cardiac death in patients with epilepsy independent of an immediately preceding seizure.
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Affiliation(s)
- Richard L Verrier
- Harvard Medical School, Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine and Department of Neurology, Boston, MA United States of America.
| | - Trudy D Pang
- Harvard Medical School, Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine and Department of Neurology, Boston, MA United States of America
| | - Bruce D Nearing
- Harvard Medical School, Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine and Department of Neurology, Boston, MA United States of America
| | - Steven C Schachter
- Harvard Medical School, Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine and Department of Neurology, Boston, MA United States of America
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53
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Chan SA, Vaseghi M, Kluge N, Shivkumar K, Ardell JL, Smith C. Fast in vivo detection of myocardial norepinephrine levels in the beating porcine heart. Am J Physiol Heart Circ Physiol 2020; 318:H1091-H1099. [PMID: 32216617 PMCID: PMC7346543 DOI: 10.1152/ajpheart.00574.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The sympathetic nervous system modulates cardiac function by controlling key parameters such as chronotropy and inotropy. Sympathetic control of ventricular function occurs through extrinsic innervation arising from the stellate ganglia and thoracic sympathetic chain. In the healthy heart, sympathetic release of norepinephrine (NE) results in positive modulation of chronotropy, inotropy, and dromotropy, significantly increasing cardiac output. However, in the setting of myocardial infarction or injury, sympathetic activation persists, contributing to heart failure and increasing the risk of arrhythmias, including sudden cardiac death. Methodologies for detection of norepinephrine in cardiac tissue are limited. Present techniques rely on microdialysis for analysis by high-performance liquid chromatography coupled to electrochemical detection (HPLC-ED), radioimmunoassay, or other immunoassays, such as enzyme-linked immunosorbent assay (ELISA). Although significant information about the release and action of norepinephrine has been obtained with these methodologies, they are limited in temporal resolution, require large sample volumes, and provide results with a significant delay after sample collection (hours to weeks). In this study, we report a novel approach for measurement of interstitial cardiac norepinephrine, using minimally invasive, electrode-based, fast-scanning cyclic voltammetry (FSCV) applied in a beating porcine heart. The first multispatial and high temporal resolution, multichannel measurements of NE release in vivo are provided. Our data demonstrate rapid changes in interstitial NE profiles with regional differences in response to coronary ischemia, sympathetic nerve stimulation, and alterations in preload/afterload. NEW & NOTEWORTHY Pharmacological, electrical, or surgical regulation of sympathetic neuronal control can be used to modulate cardiac function and treat arrhythmias. However, present methods for monitoring sympathetic release of norepinephrine in the heart are limited in spatial and temporal resolution. Here, we provide for the first time a methodology and demonstration of practice and rapid measures of individualized regional autonomic neurotransmitter levels in a beating heart. We show dynamic, spatially resolved release profiles under normal and pathological conditions.
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Affiliation(s)
- Shyue-An Chan
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio
| | - Marmar Vaseghi
- UCLA Cardiac Arrhythmia Center, UCLA Health System, University of California Los Angeles, Los Angeles, California.,UCLA Neurocardiology Research Program of Excellence, University of California Los Angeles, Los Angeles, California
| | - Nicholas Kluge
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio
| | - Kalyanam Shivkumar
- UCLA Cardiac Arrhythmia Center, UCLA Health System, University of California Los Angeles, Los Angeles, California.,UCLA Neurocardiology Research Program of Excellence, University of California Los Angeles, Los Angeles, California
| | - Jeffrey L Ardell
- UCLA Cardiac Arrhythmia Center, UCLA Health System, University of California Los Angeles, Los Angeles, California.,UCLA Neurocardiology Research Program of Excellence, University of California Los Angeles, Los Angeles, California
| | - Corey Smith
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio
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54
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Aydin MD, Acikel M, Aydin N, Aydin ME, Ahiskalioglu A, Atalay C, Ahiskalioglu EO, Erdogan F, Sipal S. Predestinating Role of Cardiac Ganglia on Heart Life Expectancy in Rabbits After Brain Death Following Subarachnoid Hemorrhage: An Experimental Study. Transplant Proc 2019; 52:61-66. [PMID: 31837820 DOI: 10.1016/j.transproceed.2019.09.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 07/11/2019] [Accepted: 09/26/2019] [Indexed: 10/25/2022]
Abstract
BACKGROUND Cardiac ganglia are rechargeable batteries of the heart. The essential role of cardiac ganglia on cardiac life expectancy has not been examined following brain death. The aim of this study was to determine cardiac ganglia numbers and neuron density following subarachnoid hemorrhage (SAH). METHODS Twenty-five hybrid rabbits were grouped as control (n = 5), sham (n = 5), and SAH (n = 15). The SAH groups' animals were subjected to injections of lethal dose of 2.00 cc autologous blood into their cisterna magna until linear EEG was obtained. The hearts of all animals were extracted following intracardiac formalin injection and examined. Cardiac ganglia and normal/degenerated neuron densities of cardiac neurons were recorded. RESULTS The mean volume of normal neuron density of ganglia was 6.980 ± 830/mm3, and the degenerated neuron density of ganglia was 3 ± 1/mm3 in the control group, 6134 ± 712/mm3; 23 ± 9/mm3 in the sham group, 3456 ± 589; 1161 ± 72/mm3 in the surviving group; and 1734 ± 341/mm3, 4259 ± 865/mm3 in the dead animals in the SAH group. The algebraic results of heart work capacity (Wh) were estimated as 1375 ± 210 Wh in the control group, 1036 ± 225 in the sham group, 800 ± 110 Wh in the surviving group, and < 100 ± 20 in the dead animals in the SAH group. Degenerated cardiac neuron density/Wh correlation is statistically meaningful between the dead in the SAH group versus the SAH-surviving, sham, and control groups (P < .0005). CONCLUSIONS Normal cardiac ganglia numbers and/or cardiac ganglia neuron density may be related to cardiac survival following brain death after subarachnoid hemorrhage.
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Affiliation(s)
- Mehmet Dumlu Aydin
- Ataturk University, Medical Faculty, Department of Neurosurgery, Erzurum, Turkey.
| | - Mahmut Acikel
- Ankara Higher Education and Research Hospital, Department of Cardiology, Ankara, Turkey
| | - Nazan Aydin
- Uskudar University, Medical Faculty, Department of Psychiatri, Erzurum, Turkey
| | - Muhammed Enes Aydin
- Ataturk University, Medical Faculty, Department of Anesthesiology and Reanimation, Erzurum, Turkey
| | - Ali Ahiskalioglu
- Ataturk University, Medical Faculty, Department of Anesthesiology and Reanimation, Erzurum, Turkey
| | - Canan Atalay
- Ataturk University, Medical Faculty, Department of Anesthesiology and Reanimation, Erzurum, Turkey
| | - Elif Oral Ahiskalioglu
- Ataturk University, Medical Faculty, Department of Anesthesiology and Reanimation, Erzurum, Turkey
| | - Fazlı Erdogan
- Ataturk Training and Research Hospital, Department of Pathology Ankara, Turkey
| | - Sare Sipal
- Ataturk University, Medical Faculty, Department of Pathology, Erzurum, Turkey
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55
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Ardell JL, Foreman RD, Armour JA, Shivkumar K. Cardiac sympathectomy and spinal cord stimulation attenuate reflex-mediated norepinephrine release during ischemia preventing ventricular fibrillation. JCI Insight 2019; 4:131648. [PMID: 31671074 DOI: 10.1172/jci.insight.131648] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 10/23/2019] [Indexed: 12/15/2022] Open
Abstract
The purpose of this study was to define the mechanism by which cardiac neuraxial decentralization or spinal cord stimulation (SCS) reduces ischemia-induced ventricular fibrillation (VF). Direct measurements of norepinephrine (NE) levels in the left ventricular interstitial fluid (ISF) by microdialysis, in response to transient (15-minute) coronary artery occlusion (CAO), were performed in anesthetized canines. Responses were studied in animals with intact neuraxes and were compared with those in which the intrathoracic component of the cardiac neuraxes (stellate ganglia) or the intrinsic cardiac neuronal (ICN) system was surgically delinked from the central nervous system and those with intact neuraxes with preemptive SCS (T1-T3). With intact neuraxes, animals with exaggerated NE release due to CAO were at increased risk for VF. During CAO, there was a 152% increase in NE when the neuraxes were intact compared with 114% following stellate decentralization and 16% following ICN decentralization. During SCS, CAO NE levels increased by 59%. Risk for CAO-induced VF was 38% in controls, 8% following decentralization, and 11% following SCS. These data indicate that ischemia-related afferent neuronal transmission differentially engages central and intrathoracic sympathetic reflexes and amplifies sympathoexcitation. Differences in regional ventricular NE release are associated with increased risk for VF. Surgical decentralization or SCS reduced NE release and VF.
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Affiliation(s)
- Jeffrey L Ardell
- UCLA Cardiac Arrhythmia Center, UCLA Health System, Los Angeles, California, USA.,Neurocardiology Research Program of Excellence and.,Molecular Cellular and Integrative Physiology, UCLA, Los Angeles, California, USA.,Department of Biomedical Sciences, East Tennessee State University, Johnson City, Tennessee, USA
| | - Robert D Foreman
- Department of Physiology, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma, USA
| | - J Andrew Armour
- UCLA Cardiac Arrhythmia Center, UCLA Health System, Los Angeles, California, USA.,Neurocardiology Research Program of Excellence and
| | - Kalyanam Shivkumar
- UCLA Cardiac Arrhythmia Center, UCLA Health System, Los Angeles, California, USA.,Neurocardiology Research Program of Excellence and.,Molecular Cellular and Integrative Physiology, UCLA, Los Angeles, California, USA.,Neuroscience Interdepartmental Programs, UCLA, Los Angeles, California, USA
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Konstam MA, Udelson JE, Butler J, Klein HU, Parker JD, Teerlink JR, Wedge PM, Saville BR, Ardell JL, Libbus I, DiCarlo LA. Impact of Autonomic Regulation Therapy in Patients with Heart Failure. Circ Heart Fail 2019; 12:e005879. [DOI: 10.1161/circheartfailure.119.005879] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Background:
The ANTHEM-HFrEF (Autonomic Regulation Therapy to Enhance Myocardial Function and Reduce Progression of Heart Failure with Reduced Ejection Fraction) pivotal study is an adaptive, open-label, randomized, controlled study evaluating whether autonomic regulation therapy will benefit patients with advanced HFrEF. While early-phase studies have supported potential use of vagus nerve stimulation to deliver autonomic regulation therapy for HFrEF, results of larger clinical trials have been inconsistent. The ANTHEM-HFrEF study uses a novel design, with adaptive sample size selection, evaluating effects on morbidity and mortality as well as symptoms and function.
Methods:
The ANTHEM-HFrEF study will randomize patients (2:1) to autonomic regulation therapy plus guideline-directed medical therapy, or guideline-directed medical therapy alone. The morbidity and mortality trial utilizes a conventional frequentist approach for analysis of the primary outcome end point—reduction in the composite of cardiovascular death or first HF hospitalization—and a Bayesian adaptive approach toward sample size selection. Embedded within the ANTHEM-HFrEF study is a second trial evaluating improvement in symptoms and function. Symptom/function success will require meeting 2 risk-related conditions (trend for reduced cardiovascular death/HF hospitalization and sufficient freedom from device-related serious adverse events) and 3 efficacy end point components (changes in left ventricular EF, 6-minute walk distance, and Kansas City Cardiomyopathy Questionnaire overall score).
Conclusions:
Vagus nerve stimulation remains a promising, yet unproven treatment in HFrEF. A successful ANTHEM-HFrEF pivotal study would provide an important advance in HFrEF treatment and offer a model for expediting evaluation of new therapies.
Clinical Trial Registration:
URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT03425422.
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Affiliation(s)
- Marvin A. Konstam
- The CardioVascular Center at Tufts Medical Center, Boston, MA (M.A.K., J.E.U.)
| | - James E. Udelson
- The CardioVascular Center at Tufts Medical Center, Boston, MA (M.A.K., J.E.U.)
| | - Javed Butler
- Department of Medicine, University of Mississippi Medical Center, Jackson, MS (J.B.)
| | - Helmut U. Klein
- Department of Medicine, University of Rochester Medical Center, NY (H.U.K.)
| | - John D. Parker
- University of Toronto, Mount Sinai Hospital, Division of Cardiology, Sinai Health Systems and University Health Network, Toronto, Canada (J.D.P.)
| | - John R. Teerlink
- Section of Cardiology, San Francisco Veterans Affairs Medical Center and School of Medicine, University of California (J.R.T.)
| | | | - Benjamin R. Saville
- Berry Consultants LLC, Austin TX and Department of Biostatistics, Vanderbilt University, Nashville TN (B.R.S.)
| | - Jeffrey L. Ardell
- Neurocardiology Center, University of California, Los Angeles (J.L.A.)
| | - Imad Libbus
- LivaNova USA Incorporated, Houston, TX (I.L., L.A.D.)
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Salavatian S, Ardell SM, Hammer M, Gibbons D, Armour JA, Ardell JL. Thoracic spinal cord neuromodulation obtunds dorsal root ganglion afferent neuronal transduction of the ischemic ventricle. Am J Physiol Heart Circ Physiol 2019; 317:H1134-H1141. [PMID: 31538809 DOI: 10.1152/ajpheart.00257.2019] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Aberrant afferent signaling drives adverse remodeling of the cardiac nervous system in ischemic heart disease. The study objective was to determine whether thoracic spinal dorsal column stimulation (SCS) modulates cardiac afferent sensory transduction of the ischemic ventricle. In anesthetized canines (n = 16), extracellular activity generated by 62 dorsal root ganglia (DRG) soma (T1-T3), with verified myocardial ischemic (MI) sensitivity, were evaluated with and without 20-min preemptive SCS (T1-T3 spinal level; 50 Hz, 90% motor threshold). Transient MI was induced by 1-min coronary artery occlusion (CAO) of the left anterior descending (LAD) or circumflex (LCX) artery, randomized as to sequence. LAD and LCX CAO activated cardiac-related DRG neurons (LAD: 0.15 ± 0.04-1.05 ± 0.20 Hz, P < 0.00002; LCX: 0.08 ± 0.02-1.90 ± 0.45 Hz, P < 0.0003). SCS decreased basal neuronal activity of neurons that responded to LAD (0.15 ± 0.04 to 0.02 ± 0.01 Hz, P < 0.006) and LCX (0.08 ± 0.02 to 0.02 ± 0.01 Hz, P < 0.003). SCS suppressed responsiveness to transient MI (LAD: 1.05 ± 0.20-0.03 ± 0.01 Hz; P < 0.0001; LCX: 1.90 ± 0.45-0.03 ± 0.01 Hz; P < 0.001). Suprathreshold SCS (1 Hz) did not activate DRG neurons antidromically (n = 10 animals). Ventricular fibrillation (VF) was associated with a rapid increase in DRG activity to a maximum of 4.39 ± 1.07 Hz at 20 s after VF induction and a return to 90% of baseline within 10 s thereafter. SCS obtunds the capacity of DRG ventricular neurites to transduce the ischemic myocardium to second-order spinal neurons, a mechanism that would blunt reflex sympathoexcitation to myocardial ischemic stress, thereby contributing to its capacity to cardioprotect.NEW & NOTEWORTHY Aberrant afferent signaling drives adverse remodeling of the cardiac nervous system in ischemic heart disease. This study determined that thoracic spinal column stimulation (SCS) obtunds the capacity of dorsal root ganglia ventricular afferent neurons to transduce the ischemic myocardium to second-order spinal neurons, a mechanism that would blunt reflex sympathoexcitation to myocardial ischemic stress. This modulation does not reflect antidromic actions of SCS but likely reflects efferent-mediated changes at the myocyte-sensory neurite interface.
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Affiliation(s)
- Siamak Salavatian
- Neurocardiology Research Program of Excellence, University of California, Los Angeles, California.,Cardiac Arrhythmia Center, University of California, Los Angeles, California
| | - Sarah M Ardell
- Neurocardiology Research Program of Excellence, University of California, Los Angeles, California.,Cardiac Arrhythmia Center, University of California, Los Angeles, California
| | - Mathew Hammer
- Neurocardiology Research Program of Excellence, University of California, Los Angeles, California.,Cardiac Arrhythmia Center, University of California, Los Angeles, California
| | - David Gibbons
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, Tennessee
| | - J Andrew Armour
- Neurocardiology Research Program of Excellence, University of California, Los Angeles, California.,Cardiac Arrhythmia Center, University of California, Los Angeles, California
| | - Jeffrey L Ardell
- Neurocardiology Research Program of Excellence, University of California, Los Angeles, California.,Cardiac Arrhythmia Center, University of California, Los Angeles, California
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Osório TG, Coutiño HE, Brugada P, Chierchia GB, De Asmundis C. Recent advances in cryoballoon ablation for atrial fibrillation. Expert Rev Med Devices 2019; 16:799-808. [PMID: 31389263 DOI: 10.1080/17434440.2019.1653181] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Introduction: Pulmonary vein isolation (PVI), by catheter ablation, represents the current treatment for drug-resistant atrial fibrillation (AF). Nowadays cryoballoon (CB) is a recognized ablation method in patients with atrial fibrillation, mainly due to its ease of use, leading to reproducible and fast procedures. This novel single shot technology literally revolutionized the approach to AF ablation. Areas covered: The historical development of the cryoballoon, ablation techniques and new approaches beyond the ordinary PVI and complications are summarized here. Expert opinion: Although cryoballoon ablation has greatly standardized the approach to PVI a few critical points still need to be clarified scientifically in order to further uniform this procedure in cath labs worldwide. Duration and dosage of the cryoapplication is undoubtedly a topic of great interest.
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Affiliation(s)
- Thiago Guimarães Osório
- Heart Rhythm Management Centre, Postgraduate course in Cardiac Electrophysiology and Pacing, Vrije Universiteit Brussel, Universitair Ziekenhuis Brussel , Brussels , Belgium
| | - Hugo-Enrique Coutiño
- Heart Rhythm Management Centre, Postgraduate course in Cardiac Electrophysiology and Pacing, Vrije Universiteit Brussel, Universitair Ziekenhuis Brussel , Brussels , Belgium
| | - Pedro Brugada
- Heart Rhythm Management Centre, Postgraduate course in Cardiac Electrophysiology and Pacing, Vrije Universiteit Brussel, Universitair Ziekenhuis Brussel , Brussels , Belgium
| | - Gian-Battista Chierchia
- Heart Rhythm Management Centre, Postgraduate course in Cardiac Electrophysiology and Pacing, Vrije Universiteit Brussel, Universitair Ziekenhuis Brussel , Brussels , Belgium
| | - Carlo De Asmundis
- Heart Rhythm Management Centre, Postgraduate course in Cardiac Electrophysiology and Pacing, Vrije Universiteit Brussel, Universitair Ziekenhuis Brussel , Brussels , Belgium
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Osório TG, Coutiño HE, Iacopino S, Sieira J, Ströker E, Martín-Sierra C, Salghetti F, Paparella G, Aryana A, Varnavas V, Terasawa M, Brugada P, de Asmundis C, Chierchia GB. Quantification of acute parasympathetic denervation during cryoballoon ablation by using extracardiac vagal stimulation. J Cardiovasc Med (Hagerstown) 2019; 20:107-113. [DOI: 10.2459/jcm.0000000000000760] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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60
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Kim MY, Sikkel MB, Hunter RJ, Haywood GA, Tomlinson DR, Tayebjee MH, Ali RL, Cantwell CD, Gonna H, Sandler BC, Lim E, Furniss G, Panagopoulos D, Begg G, Dhillon G, Hill NJ, O'Neill J, Francis DP, Lim PB, Peters NS, Linton NWF, Kanagaratnam P. A novel approach to mapping the atrial ganglionated plexus network by generating a distribution probability atlas. J Cardiovasc Electrophysiol 2018; 29:1624-1634. [PMID: 30168232 PMCID: PMC6369684 DOI: 10.1111/jce.13723] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 08/16/2018] [Accepted: 08/23/2018] [Indexed: 11/27/2022]
Abstract
Introduction The ganglionated plexuses (GPs) of the intrinsic cardiac autonomic system are implicated in arrhythmogenesis. GP localization by stimulation of the epicardial fat pads to produce atrioventricular dissociating (AVD) effects is well described. We determined the anatomical distribution of the left atrial GPs that influence atrioventricular (AV) dissociation. Methods and Results High frequency stimulation was delivered through a Smart‐Touch catheter in the left atrium of patients undergoing atrial fibrillation (AF) ablation. Three dimensional locations of points tested throughout the entire chamber were recorded on the CARTO™ system. Impact on the AV conduction was categorized as ventricular asystole, bradycardia, or no effect. CARTO maps were exported, registered, and transformed onto a reference left atrial geometry using a custom software, enabling data from multiple patients to be overlaid. In 28 patients, 2108 locations were tested and 283 sites (13%) demonstrated (AVD‐GP) effects. There were 10 AVD‐GPs (interquartile range, 11.5) per patient. Eighty percent (226) produced asystole and 20% (57) showed bradycardia. The distribution of the two groups was very similar. Highest probability of AVD‐GPs (>20%) was identified in: inferoseptal portion (41%) and right inferior pulmonary vein base (30%) of the posterior wall, right superior pulmonary vein antrum (31%). Conclusion It is feasible to map the entire left atrium for AVD‐GPs before AF ablation. Aggregated data from multiple patients, producing a distribution probability atlas of AVD‐GPs, identified three regions with a higher likelihood for finding AVD‐GPs and these matched the histological descriptions. This approach could be used to better characterize the autonomic network.
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Affiliation(s)
- Min-Young Kim
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Markus B Sikkel
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK
| | - Ross J Hunter
- Department of Cardiology, The Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, UK
| | - Guy A Haywood
- Department of Cardiology, Derriford Hospital, Plymouth Hospitals NHS Trust, Plymouth, UK
| | - David R Tomlinson
- Department of Cardiology, Derriford Hospital, Plymouth Hospitals NHS Trust, Plymouth, UK
| | - Muzahir H Tayebjee
- Department of Cardiology, Leeds General Infirmary, Leeds Teaching Hospitals NHS Trust, Leeds, UK
| | - Rheeda L Ali
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Chris D Cantwell
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Hanney Gonna
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Belinda C Sandler
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Elaine Lim
- Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK
| | - Guy Furniss
- Department of Cardiology, Derriford Hospital, Plymouth Hospitals NHS Trust, Plymouth, UK
| | - Dimitrios Panagopoulos
- Department of Cardiology, Derriford Hospital, Plymouth Hospitals NHS Trust, Plymouth, UK
| | - Gordon Begg
- Department of Cardiology, Derriford Hospital, Plymouth Hospitals NHS Trust, Plymouth, UK
| | - Gurpreet Dhillon
- Department of Cardiology, The Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, UK
| | - Nicola J Hill
- Department of Cardiology, Leeds General Infirmary, Leeds Teaching Hospitals NHS Trust, Leeds, UK
| | - James O'Neill
- Department of Cardiology, Leeds General Infirmary, Leeds Teaching Hospitals NHS Trust, Leeds, UK
| | - Darrel P Francis
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK
| | - Phang Boon Lim
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK
| | - Nicholas S Peters
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK
| | - Nick W F Linton
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK
| | - Prapa Kanagaratnam
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK
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Fioranelli M, Bottaccioli AG, Bottaccioli F, Bianchi M, Rovesti M, Roccia MG. Stress and Inflammation in Coronary Artery Disease: A Review Psychoneuroendocrineimmunology-Based. Front Immunol 2018; 9:2031. [PMID: 30237802 PMCID: PMC6135895 DOI: 10.3389/fimmu.2018.02031] [Citation(s) in RCA: 166] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 08/17/2018] [Indexed: 01/08/2023] Open
Abstract
Recent findings have deeply changed the current view of coronary heart disease, going beyond the simplistic model of atherosclerosis as a passive process involving cholesterol build-up in the subintimal space of the arteries until their final occlusion and/or thrombosis and instead focusing on the key roles of inflammation and the immune system in plaque formation and destabilization. Chronic inflammation is a typical hallmark of cardiac disease, worsening outcomes irrespective of serum cholesterol levels. Low-grade chronic inflammation correlates with higher incidence of several non-cardiac diseases, including depression, and chronic depression is now listed among the most important cardiovascular risk factors for poor prognosis among patients with myocardial infarction. In this review, we include recent evidence describing the immune and endocrine properties of the heart and their critical roles in acute ischaemic damage and in post-infarct myocardial remodeling. The importance of the central and autonomic regulation of cardiac functions, namely, the neuro-cardiac axis, is extensively explained, highlighting the roles of acute and chronic stress, circadian rhythms, emotions and the social environment in triggering acute cardiac events and worsening heart function and metabolism in chronic cardiovascular diseases. We have also included specific sections related to stress-induced myocardial ischaemia measurements and stress cardiomyopathy. The complex network of reciprocal interconnections between the heart and the main biological systems we have presented in this paper provides a new vision of cardiovascular science based on psychoneuroendocrineimmunology.
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Affiliation(s)
- Massimo Fioranelli
- Department of Nuclear Physics, Sub-Nuclear and Radiation, Guglielmo Marconi University, Rome, Italy
- Società Italiana di Psiconeuroendocrinoimmunologia, Rome, Italy
| | - Anna G. Bottaccioli
- Società Italiana di Psiconeuroendocrinoimmunologia, Rome, Italy
- Department of Internal Medicine, Sapienza University, Rome, Italy
| | - Francesco Bottaccioli
- Società Italiana di Psiconeuroendocrinoimmunologia, Rome, Italy
- Department of Clinical Medicine, University of l'Aquila, L'Aquila, Italy
- Department of Neurosciences “Rita Levi Montalcini”, University of Turin, Rome, Italy
| | - Maria Bianchi
- Department of Nuclear Physics, Sub-Nuclear and Radiation, Guglielmo Marconi University, Rome, Italy
| | - Miriam Rovesti
- Department of Dermatology, University of Parma, Parma, Italy
| | - Maria G. Roccia
- Department of Nuclear Physics, Sub-Nuclear and Radiation, Guglielmo Marconi University, Rome, Italy
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Chauhan RA, Coote J, Allen E, Pongpaopattanakul P, Brack KE, Ng GA. Functional selectivity of cardiac preganglionic sympathetic neurones in the rabbit heart. Int J Cardiol 2018; 264:70-78. [PMID: 29657079 PMCID: PMC5968349 DOI: 10.1016/j.ijcard.2018.03.119] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 03/21/2018] [Accepted: 03/26/2018] [Indexed: 01/26/2023]
Abstract
BACKGROUND Studies have shown regional and functional selectivity of cardiac postganglionic neurones indicating there might exist a similar heterogeneity in spinal segmental preganglionic neurones, which requires further investigation. METHODS Right and left sympathetic chains were electrically stimulated from T6 to T1 in the innervated isolated rabbit heart preparation (n = 18). Sinus rate, left ventricular pressure, retrograde ventriculo-atrial conduction, monophasic action potential duration, effective refractory period, ventricular fibrillation threshold and electrical restitution were measured. RESULTS Right sympathetic stimulation had a greater influence on heart rate (T1-T2: right; 59.9 ± 6.0%, left; 41.1 ± 5.6% P < 0.001) and left stimulation had greater effects on left ventricular pressure (T1-T2: right; 20.7 ± 3.2%, left; 40.3 ± 5.4%, P < 0.01) and ventriculo-atrial conduction (T1-T2: right; -6.8 ± 1.1%, left; -15.5 ± 0.2%) at all levels, with greater effects at rostral levels (T1-T3). Left sympathetic stimulation caused shorter monophasic action potentials at the base (T4-T5: right; 119.3 ± 2.7 ms, left; 114.7 ± 2.5 ms. P < 0.05) and apex (T4-T5: right; 118.8 ± 1.2 ms, left; 114.6 ± 2.6 ms. P < 0.05), greater shortening of effective refractory period (T4-T5: right; -3.6 ± 1.3%, left; -7.7 ± 1.8%. P < 0.05), a steeper maximum slope of restitution (T4-T5 base: right; 1.3 ± 0.2, left; 1.8 ± 0.2. P < 0.01. T4-T5 apex: right; 1.0 ± 0.2, left; 1.6 ± 0.3. P < 0.05) and a greater decrease in ventricular fibrillation threshold (T4-T5: right; -22.3 ± 6.8%, left;-39.0 ± 1.7%), with dominant effects at caudal levels (T4-T6). CONCLUSIONS The preganglionic sympathetic efferent axons show functionally distinct pathways to the heart. The caudal segments (T4-T6) of the left sympathetic chain had a greater potential for arrhythmia generation and hence could pose a target for more focused clinical treatments for impairments in cardiac function.
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Affiliation(s)
- Reshma A Chauhan
- Department of Cardiovascular Sciences, University of Leicester, UK
| | - John Coote
- Department of Cardiovascular Sciences, University of Leicester, UK; University of Birmingham, UK
| | - Emily Allen
- Department of Cardiovascular Sciences, University of Leicester, UK
| | | | - Kieran E Brack
- Department of Cardiovascular Sciences, University of Leicester, UK
| | - G Andre Ng
- Department of Cardiovascular Sciences, University of Leicester, UK; NIHR Leicester Biomedical Research Centre, Leicester, UK; University Hospitals of Leicester NHS Trust, Leicester, UK.
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63
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Garabelli P, Stavrakis S, Kenney JFA, Po SS. Effect of 28-mm Cryoballoon Ablation on Major Atrial Ganglionated Plexi. JACC Clin Electrophysiol 2018; 4:831-838. [PMID: 29929678 DOI: 10.1016/j.jacep.2017.12.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 12/29/2017] [Accepted: 12/29/2017] [Indexed: 11/18/2022]
Abstract
OBJECTIVES The authors intended to investigate if 28-mm cryoballoon (CB) ablation also modifies the 4 major atrial ganglionaated plexi (GP). BACKGROUND The major atrial GP facilitate the initiation and maintenance of atrial fibrillation (AF). The 28-mm CB covers a large surface area of the left atrium and probably the GP areas. METHODS High-frequency stimulation (20 Hz) was delivered to the area of anterior right GP (ARGP), inferior right GP, superior left (SLGP), and inferior left GP (ILGP). Positive GP sites were defined as a prolongation of R-wave to R-wave (RR) interval during AF by >50%. The area of each GP before and after CB ablation was compared. RESULTS A total of 18 patients with paroxysmal AF who underwent CB and radiofrequency ablation and had positive GP sites were reviewed. The Wilcoxon signed-rank test was used to assess the effects of CB ablation on each GP. There was a statistically significant difference in the area of all 4 GP after CB ablation: 1) ARGP area: 2.9 cm2 (interquartile range [IQR]: 2.1 to 3.5 cm2) pre-CB, 0.1 cm2 (IQR: 0 to 0.6 cm2) post-CB, p = 0.0002; 2) inferior right GP area: 2.1 cm2 (IQR: 0.9 to 2.9 cm2) pre-CB, 0.5 cm2 (IQR: 0 to 1.7 cm2) post-CB, p = 0.001; 3) SLGP area: 1.4 cm2 (IQR: 0.6 to 2.4 cm2) pre-CB, 0 cm2 (IQR: 0 to 0 cm2) post-CB, p = 0.0002; and 4) ILGP area: 1.3 cm2 (IQR: 0.3 to 2.2 cm2) pre-CB, 0.3 cm2 (IQR: 0 to 1.6 cm2) post-CB, p = 0.008. CONCLUSIONS The surface area of all 4 of the major atrial GP was substantially reduced by CB ablation. The SLGP and ARGP had the largest, whereas the ILGP had the least percent of reduction following CB ablation. Part of the therapeutic effects of CB ablation may result from modifying the 4 major atrial GP.
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Affiliation(s)
- Paul Garabelli
- Section of Cardiovascular Diseases and Heart Rhythm Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Stavros Stavrakis
- Section of Cardiovascular Diseases and Heart Rhythm Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - John F A Kenney
- Section of Cardiovascular Diseases and Heart Rhythm Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Sunny S Po
- Section of Cardiovascular Diseases and Heart Rhythm Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
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Basalay MV, Davidson SM, Gourine AV, Yellon DM. Neural mechanisms in remote ischaemic conditioning in the heart and brain: mechanistic and translational aspects. Basic Res Cardiol 2018; 113:25. [PMID: 29858664 PMCID: PMC5984640 DOI: 10.1007/s00395-018-0684-z] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 05/02/2018] [Accepted: 05/23/2018] [Indexed: 12/13/2022]
Abstract
Remote ischaemic conditioning (RIC) is a promising method of cardioprotection, with numerous clinical studies having demonstrated its ability to reduce myocardial infarct size and improve prognosis. On the other hand, there are several clinical trials, in particular those conducted in the setting of elective cardiac surgery, that have failed to show any benefit of RIC. These contradictory data indicate that there is insufficient understanding of the mechanisms underlying RIC. RIC is now known to signal indiscriminately, protecting not only the heart, but also other organs. In particular, experimental studies have demonstrated that it is able to reduce infarct size in an acute ischaemic stroke model. However, the mechanisms underlying RIC-induced neuroprotection are even less well understood than for cardioprotection. The existence of bidirectional feedback interactions between the heart and the brain suggests that the mechanisms of RIC-induced neuroprotection and cardioprotection should be studied as a whole. This review, therefore, addresses the topic of the neural component of the RIC mechanism.
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Affiliation(s)
- Marina V Basalay
- The Hatter Cardiovascular Institute, University College London, 67 Chenies Mews, London, WC1E 6HX, UK
| | - Sean M Davidson
- The Hatter Cardiovascular Institute, University College London, 67 Chenies Mews, London, WC1E 6HX, UK
| | - Andrey V Gourine
- Department of Cardiology, Karolinska University Hospital, 171 76, Stockholm, Sweden
| | - Derek M Yellon
- The Hatter Cardiovascular Institute, University College London, 67 Chenies Mews, London, WC1E 6HX, UK.
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65
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Shivkumar K, Ardell JL. Vagal Neuromodulation for Atrial Arrhythmias. JACC Clin Electrophysiol 2018; 3:939-941. [PMID: 29759718 DOI: 10.1016/j.jacep.2017.06.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 06/13/2017] [Accepted: 06/30/2017] [Indexed: 12/21/2022]
Affiliation(s)
- Kalyanam Shivkumar
- University of California-Los Angeles Cardiac Arrhythmia Center, David Geffen School of Medicine, Los Angeles, California; University of California-Los Angeles Neurocardiology Research Center of Excellence, David Geffen School of Medicine, Los Angeles, California.
| | - Jeffrey L Ardell
- University of California-Los Angeles Cardiac Arrhythmia Center, David Geffen School of Medicine, Los Angeles, California; University of California-Los Angeles Neurocardiology Research Center of Excellence, David Geffen School of Medicine, Los Angeles, California
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66
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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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67
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Zaglia T, Mongillo M. Cardiac sympathetic innervation, from a different point of (re)view. J Physiol 2018; 595:3919-3930. [PMID: 28240352 DOI: 10.1113/jp273120] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 02/23/2017] [Indexed: 12/25/2022] Open
Abstract
The audience of basic and clinical scientists is familiar with the notion that the sympathetic nervous system controls heart function during stresses. However, evidence indicates that the neurogenic control of the heart spans from the maintenance of housekeeping functions in resting conditions to the recruitment of maximal performance, in the fight-or-flight responses, across a whole range of intermediate states. To perform such sophisticated functions, sympathetic ganglia integrate both peripheral and central inputs, and transmit information to the heart via 'motor' neurons, directly interacting with target cardiomyocytes. To date, the dynamics and mode of communication between these two cell types, which determine how neuronal information is adequately translated into the wide spectrum of cardiac responses, are still blurry. By combining the anatomical and structural information brought to light by recent imaging technologies and the functional evidence in cellular systems, we focus on the interface between neurons and cardiomyocytes, and advocate the existence of a specific 'neuro-cardiac junction', where sympathetic neurotransmission occurs in a 'quasi-synaptic' way. The properties of such junctional-type communication fit well with those of the physiological responses elicited by the cardiac sympathetic nervous system, and explain its ability to tune heart function with precision, specificity and elevated temporal resolution.
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Affiliation(s)
- Tania Zaglia
- Department of Cardiac, Thoracic and Vascular Sciences, via Giustiniani 2, 35128, University of Padova, Padova, Italy.,Department of Biomedical Sciences, via Ugo Bassi 58/B, 35131, University of Padova, Padova, Italy.,Venetian Institute of Molecular Medicine, via G.Orus, 2, 35129, Padova, Italy
| | - Marco Mongillo
- Department of Biomedical Sciences, via Ugo Bassi 58/B, 35131, University of Padova, Padova, Italy.,Venetian Institute of Molecular Medicine, via G.Orus, 2, 35129, Padova, Italy.,CNR institute of Neurosciences, viale Colombo 3, 35133, Padova, Italy
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68
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Autonomic Control of the Heart. Neuromodulation 2018. [DOI: 10.1016/b978-0-12-805353-9.00104-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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69
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Neuromodulation Therapies for Cardiac Disease. Neuromodulation 2018. [DOI: 10.1016/b978-0-12-805353-9.00129-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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70
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Ardell JL, Nier H, Hammer M, Southerland EM, Ardell CL, Beaumont E, KenKnight BH, Armour JA. Defining the neural fulcrum for chronic vagus nerve stimulation: implications for integrated cardiac control. J Physiol 2017; 595:6887-6903. [PMID: 28862330 PMCID: PMC5685838 DOI: 10.1113/jp274678] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 08/14/2017] [Indexed: 12/12/2022] Open
Abstract
KEY POINTS The evoked cardiac response to bipolar cervical vagus nerve stimulation (VNS) reflects a dynamic interaction between afferent mediated decreases in central parasympathetic drive and suppressive effects evoked by direct stimulation of parasympathetic efferent axons to the heart. The neural fulcrum is defined as the operating point, based on frequency-amplitude-pulse width, where a null heart rate response is reproducibly evoked during the on-phase of VNS. Cardiac control, based on the principal of the neural fulcrum, can be elicited from either vagus. Beta-receptor blockade does not alter the tachycardia phase to low intensity VNS, but can increase the bradycardia to higher intensity VNS. While muscarinic cholinergic blockade prevented the VNS-induced bradycardia, clinically relevant doses of ACE inhibitors, beta-blockade and the funny channel blocker ivabradine did not alter the VNS chronotropic response. While there are qualitative differences in VNS heart control between awake and anaesthetized states, the physiological expression of the neural fulcrum is maintained. ABSTRACT Vagus nerve stimulation (VNS) is an emerging therapy for treatment of chronic heart failure and remains a standard of therapy in patients with treatment-resistant epilepsy. The objective of this work was to characterize heart rate (HR) responses (HRRs) during the active phase of chronic VNS over a wide range of stimulation parameters in order to define optimal protocols for bidirectional bioelectronic control of the heart. In normal canines, bipolar electrodes were chronically implanted on the cervical vagosympathetic trunk bilaterally with anode cephalad to cathode (n = 8, 'cardiac' configuration) or with electrode positions reversed (n = 8, 'epilepsy' configuration). In awake state, HRRs were determined for each combination of pulse frequency (2-20 Hz), intensity (0-3.5 mA) and pulse widths (130-750 μs) over 14 months. At low intensities and higher frequency VNS, HR increased during the VNS active phase owing to afferent modulation of parasympathetic central drive. When functional effects of afferent and efferent fibre activation were balanced, a null HRR was evoked (defined as 'neural fulcrum') during which HRR ≈ 0. As intensity increased further, HR was reduced during the active phase of VNS. While qualitatively similar, VNS delivered in the epilepsy configuration resulted in more pronounced HR acceleration and reduced HR deceleration during VNS. At termination, under anaesthesia, transection of the vagi rostral to the stimulation site eliminated the augmenting response to VNS and enhanced the parasympathetic efferent-mediated suppressing effect on electrical and mechanical function of the heart. In conclusion, VNS activates central then peripheral aspects of the cardiac nervous system. VNS control over cardiac function is maintained during chronic therapy.
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Affiliation(s)
- Jeffrey L. Ardell
- UCLA Neurocardiology Research Center of Excellence and UCLA Cardiac Arrhythmia Center, Los AngelesLos AngelesCAUSA
| | - Heath Nier
- Biomedical SciencesEast Tennessee State UniversityJohnson CityTNUSA
| | - Matthew Hammer
- UCLA Neurocardiology Research Center of Excellence and UCLA Cardiac Arrhythmia Center, Los AngelesLos AngelesCAUSA
| | | | | | - Eric Beaumont
- Biomedical SciencesEast Tennessee State UniversityJohnson CityTNUSA
| | | | - J. Andrew Armour
- UCLA Neurocardiology Research Center of Excellence and UCLA Cardiac Arrhythmia Center, Los AngelesLos AngelesCAUSA
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71
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Salavatian S, Beaumont E, Gibbons D, Hammer M, Hoover DB, Armour JA, Ardell JL. Thoracic spinal cord and cervical vagosympathetic neuromodulation obtund nodose sensory transduction of myocardial ischemia. Auton Neurosci 2017; 208:57-65. [PMID: 28919363 DOI: 10.1016/j.autneu.2017.08.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 08/07/2017] [Accepted: 08/16/2017] [Indexed: 12/01/2022]
Abstract
BACKGROUND Autonomic regulation therapy involving either vagus nerve stimulation (VNS) or spinal cord stimulation (SCS) represents emerging bioelectronic therapies for heart disease. The objective of this study was to determine if VNS and/or SCS modulate primary cardiac afferent sensory transduction of the ischemic myocardium. METHODS Using extracellular recordings in 19 anesthetized canines, of 88 neurons evaluated, 36 ventricular-related nodose ganglia sensory neurons were identified by their functional activity responses to epicardial touch, chemical activation of their sensory neurites (epicardial veratridine) and great vessel (descending aorta or inferior vena cava) occlusion. Neural responses to 1min left anterior descending (LAD) coronary artery occlusion (CAO) were then evaluated. These interventions were then studied following either: i) SCS [T1-T3 spinal level; 50Hz, 90% motor threshold] or ii) cervical VNS [15-20Hz; 1.2× threshold]. RESULTS LAD occlusion activated 66% of identified nodose ventricular sensory neurons (0.33±0.08-0.79±0.20Hz; baseline to CAO; p<0.002). Basal activity of cardiac-related nodose neurons was differentially reduced by VNS (0.31±0.11 to 0.05±0.02Hz; p<0.05) as compared to SCS (0.36±0.12 to 0.28±0.14, p=0.59), with their activity response to transient LAD CAO being suppressed by either SCS (0.85±0.39-0.11±0.04Hz; p<0.03) or VNS (0.75±0.27-0.12±0.05Hz; p<0.04). VNS did not alter evoked neural responses of cardiac-related nodose neurons to great vessel occlusion. CONCLUSIONS Both VNS and SCS obtund ventricular ischemia induced enhancement of nodose afferent neuronal inputs to the medulla.
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Affiliation(s)
- Siamak Salavatian
- UCLA Neurocardiology Research Program of Excellence, Los Angeles, CA, United States; UCLA Cardiac Arrhythmia Center, Los Angeles, CA, United States
| | - Eric Beaumont
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, TN, United States; Center of Excellence in Inflammation, Infectious Disease and Immunity, East Tennessee State University, Johnson City, TN, United States
| | - David Gibbons
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, TN, United States
| | - Matthew Hammer
- UCLA Neurocardiology Research Program of Excellence, Los Angeles, CA, United States
| | - Donald B Hoover
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, TN, United States; Center of Excellence in Inflammation, Infectious Disease and Immunity, East Tennessee State University, Johnson City, TN, United States
| | - J Andrew Armour
- UCLA Neurocardiology Research Program of Excellence, Los Angeles, CA, United States; UCLA Cardiac Arrhythmia Center, Los Angeles, CA, United States
| | - Jeffrey L Ardell
- UCLA Neurocardiology Research Program of Excellence, Los Angeles, CA, United States; UCLA Cardiac Arrhythmia Center, Los Angeles, CA, United States.
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MacDonald EA, Stoyek MR, Rose RA, Quinn TA. Intrinsic regulation of sinoatrial node function and the zebrafish as a model of stretch effects on pacemaking. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2017; 130:198-211. [PMID: 28743586 DOI: 10.1016/j.pbiomolbio.2017.07.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 07/17/2017] [Accepted: 07/21/2017] [Indexed: 12/18/2022]
Abstract
Excitation of the heart occurs in a specialised region known as the sinoatrial node (SAN). Tight regulation of SAN function is essential for the maintenance of normal heart rhythm and the response to (patho-)physiological changes. The SAN is regulated by extrinsic (central nervous system) and intrinsic (neurons, peptides, mechanics) factors. The positive chronotropic response to stretch in particular is essential for beat-by-beat adaptation to changes in hemodynamic load. Yet, the mechanism of this stretch response is unknown, due in part to the lack of an appropriate experimental model for targeted investigations. We have been investigating the zebrafish as a model for the study of intrinsic regulation of SAN function. In this paper, we first briefly review current knowledge of the principal components of extrinsic and intrinsic SAN regulation, derived primarily from experiments in mammals, followed by a description of the zebrafish as a novel experimental model for studies of intrinsic SAN regulation. This mini-review is followed by an original investigation of the response of the zebrafish isolated SAN to controlled stretch. Stretch causes an immediate and continuous increase in beating rate in the zebrafish isolated SAN. This increase reaches a maximum part way through a period of sustained stretch, with the total change dependent on the magnitude and direction of stretch. This is comparable to what occurs in isolated SAN from most mammals (including human), suggesting that the zebrafish is a novel experimental model for the study of mechanisms involved in the intrinsic regulation of SAN function by mechanical effects.
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Affiliation(s)
- Eilidh A MacDonald
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Canada
| | - Matthew R Stoyek
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Canada
| | - Robert A Rose
- Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada
| | - T Alexander Quinn
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Canada; School of Biomedical Engineering, Dalhousie University, Halifax, Canada.
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Kember G, Ardell JL, Shivkumar K, Armour JA. Recurrent myocardial infarction: Mechanisms of free-floating adaptation and autonomic derangement in networked cardiac neural control. PLoS One 2017; 12:e0180194. [PMID: 28692680 PMCID: PMC5503241 DOI: 10.1371/journal.pone.0180194] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 06/12/2017] [Indexed: 12/20/2022] Open
Abstract
The cardiac nervous system continuously controls cardiac function whether or not pathology is present. While myocardial infarction typically has a major and catastrophic impact, population studies have shown that longer-term risk for recurrent myocardial infarction and the related potential for sudden cardiac death depends mainly upon standard atherosclerotic variables and autonomic nervous system maladaptations. Investigative neurocardiology has demonstrated that autonomic control of cardiac function includes local circuit neurons for networked control within the peripheral nervous system. The structural and adaptive characteristics of such networked interactions define the dynamics and a new normal for cardiac control that results in the aftermath of recurrent myocardial infarction and/or unstable angina that may or may not precipitate autonomic derangement. These features are explored here via a mathematical model of cardiac regulation. A main observation is that the control environment during pathology is an extrapolation to a setting outside prior experience. Although global bounds guarantee stability, the resulting closed-loop dynamics exhibited while the network adapts during pathology are aptly described as 'free-floating' in order to emphasize their dependence upon details of the network structure. The totality of the results provide a mechanistic reasoning that validates the clinical practice of reducing sympathetic efferent neuronal tone while aggressively targeting autonomic derangement in the treatment of ischemic heart disease.
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Affiliation(s)
- Guy Kember
- Dept. of Engineering Mathematics and Internetworking/Faculty of Engineering/Dalhousie University, Halifax, NS, Canada
- * E-mail:
| | - Jeffrey L. Ardell
- David Geffen School of Medicine/Cardiac Arrhythmia Center, University of California – Los Angeles (UCLA), Los Angeles, CA, United States of America
| | - Kalyanam Shivkumar
- David Geffen School of Medicine/Cardiac Arrhythmia Center, University of California – Los Angeles (UCLA), Los Angeles, CA, United States of America
| | - J. Andrew Armour
- David Geffen School of Medicine/Cardiac Arrhythmia Center, University of California – Los Angeles (UCLA), Los Angeles, CA, United States of America
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