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Lozano WM, Ortiz-Guzmán JE, Arias-Mutis O, Bizy A, Genovés P, Such-Miquel L, Alberola A, Chorro FJ, Zarzoso M, Calvo CJ. Modifications of long-term heart rate variability produced in an experimental model of diet-induced metabolic syndrome. Interface Focus 2023; 13:20230030. [PMID: 38106920 PMCID: PMC10722215 DOI: 10.1098/rsfs.2023.0030] [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: 07/13/2023] [Accepted: 10/13/2023] [Indexed: 12/19/2023] Open
Abstract
Metabolic syndrome (MetS) has been linked to a higher prevalence of cardiac arrhythmias, the most frequent being atrial fibrillation, but the mechanisms are not well understood. One possible underlying mechanism may be an abnormal modulation of autonomic nervous system activity, which can be quantified by analysing heart rate variability (HRV). Our aim was to investigate the modifications of long-term HRV in an experimental model of diet-induced MetS to identify the early changes in HRV and the link between autonomic dysregulation and MetS components. NZW rabbits were randomly assigned to control (n = 10) or MetS (n = 10) groups, fed 28 weeks with high-fat, high-sucrose diet. 24-hour recordings were used to analyse HRV at week 28 using time-domain, frequency-domain and nonlinear analyses. Time-domain analysis showed a decrease in RR interval and triangular index (Ti). In the frequency domain, we found a decrease in the low frequency band. Nonlinear analyses showed a decrease in DFA-α1 and DFA-α2 (detrended fluctuations analysis) and maximum multiscale entropy. The strongest association between HRV parameters and markers of MetS was found between Ti and mean arterial pressure, and Ti and left atrial diameter, which could point towards the initial changes induced by the autonomic imbalance in MetS.
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Affiliation(s)
- W. M. Lozano
- Department of Physiology, Universitat de València, Valencia, Comunitat Valenciana, Spain
- School of Physiotherapy, Universidad Industrial de Santander, Bucaramanga, Santander, Colombia
| | - J. E. Ortiz-Guzmán
- Department of Physiology, Universitat de València, Valencia, Comunitat Valenciana, Spain
| | - O. Arias-Mutis
- Department of Biomedical Sciences, CEU Cardenal Herrera, Moncada, Valenciana, Spain
- Health Research Institute - Instituto de Investigación Sanitaria del Hospital Clínico Universitario de Valencia (INCLIVA), Valencia, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBER-CV), Madrid, Spain
| | - A. Bizy
- Department of Biomedical Sciences, CEU Cardenal Herrera, Moncada, Valenciana, Spain
| | - P. Genovés
- Department of Physiology, Universitat de València, Valencia, Comunitat Valenciana, Spain
| | - L. Such-Miquel
- Department of Physiotherapy, Universitat de València, València, Spain
| | - A. Alberola
- Department of Physiology, Universitat de València, Valencia, Comunitat Valenciana, Spain
| | - F. J. Chorro
- Health Research Institute - Instituto de Investigación Sanitaria del Hospital Clínico Universitario de Valencia (INCLIVA), Valencia, Spain
- Department of Medicine, Universitat de València, València, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBER-CV), Madrid, Spain
| | - M. Zarzoso
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBER-CV), Madrid, Spain
- Department of Physiotherapy, Universitat de València, València, Spain
| | - C. J. Calvo
- Department of Physiology, Universitat de València, Valencia, Comunitat Valenciana, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBER-CV), Madrid, Spain
- CSIC-UPV, Instrumentation for Molecular Imaging Technologies Research Institute (I3M), Universitat Politècnica de València, València, Spain
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2
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Endothelin System and Ischemia-Induced Ventricular Tachyarrhythmias. Life (Basel) 2022; 12:life12101627. [PMID: 36295062 PMCID: PMC9605000 DOI: 10.3390/life12101627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 10/13/2022] [Accepted: 10/15/2022] [Indexed: 11/17/2022] Open
Abstract
Despite the contemporary treatment of acute coronary syndromes, arrhythmic complications occurring prior to medical attendance remain significant, mandating in-depth understanding of the underlying mechanisms. Sympathetic activation has long been known to play a key role in the pathophysiology of ischemia-induced arrhythmias, but the regulating factors remain under investigation. Several lines of evidence implicate the endothelin system (a family of three isopeptides and two specific receptors) as an important modulator of sympathetic activation in the setting of acute coronary syndromes. Such interaction is present in the heart and in the adrenal medulla, whereas less is known on the effects of the endothelin system on the central autonomic network. This article summarizes the current state-of-the-art, placing emphasis on early-phase arrhythmogenesis, and highlights potential areas of future research.
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Cui X, Sun G, Cao H, Liu Q, Liu K, Wang S, Zhu B, Gao X. Referred Somatic Hyperalgesia Mediates Cardiac Regulation by the Activation of Sympathetic Nerves in a Rat Model of Myocardial Ischemia. Neurosci Bull 2022; 38:386-402. [PMID: 35471719 PMCID: PMC9068860 DOI: 10.1007/s12264-022-00841-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 12/13/2021] [Indexed: 01/09/2023] Open
Abstract
Myocardial ischemia (MI) causes somatic referred pain and sympathetic hyperactivity, and the role of sensory inputs from referred areas in cardiac function and sympathetic hyperactivity remain unclear. Here, in a rat model, we showed that MI not only led to referred mechanical hypersensitivity on the forelimbs and upper back, but also elicited sympathetic sprouting in the skin of the referred area and C8-T6 dorsal root ganglia, and increased cardiac sympathetic tone, indicating sympathetic-sensory coupling. Moreover, intensifying referred hyperalgesic inputs with noxious mechanical, thermal, and electro-stimulation (ES) of the forearm augmented sympathetic hyperactivity and regulated cardiac function, whereas deafferentation of the left brachial plexus diminished sympathoexcitation. Intradermal injection of the α2 adrenoceptor (α2AR) antagonist yohimbine and agonist dexmedetomidine in the forearm attenuated the cardiac adjustment by ES. Overall, these findings suggest that sensory inputs from the referred pain area contribute to cardiac functional adjustment via peripheral α2AR-mediated sympathetic-sensory coupling.
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Affiliation(s)
- Xiang Cui
- Department of Physiology, Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Guang Sun
- Department of Physiology, Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China.,Research Center of Traditional Chinese Medicine, The Affiliated Hospital of Changchun University of Chinese Medicine, Changchun, Jilin, 130021, China
| | - Honglei Cao
- Department of Cardiology, Jining No. 1 People's Hospital, Jining, 272100, Shandong, China
| | - Qun Liu
- Department of Needling Manipulation, Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Kun Liu
- Department of Physiology, Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Shuya Wang
- Department of Physiology, Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Bing Zhu
- Department of Physiology, Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
| | - Xinyan Gao
- Department of Physiology, Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
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4
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Qi L, Hu H, Wang Y, Hu H, Wang K, Li P, Yin J, Shi Y, Wang Y, Zhao Y, Lyu H, Feng M, Xue M, Li X, Li Y, Yan S. New insights into the central sympathetic hyperactivity post-myocardial infarction: Roles of METTL3-mediated m 6 A methylation. J Cell Mol Med 2022; 26:1264-1280. [PMID: 35040253 PMCID: PMC8831944 DOI: 10.1111/jcmm.17183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 12/23/2021] [Accepted: 01/03/2022] [Indexed: 11/28/2022] Open
Abstract
Ventricular arrhythmias (VAs) triggers by sympathetic nerve hyperactivity contribute to sudden cardiac death in myocardial infarction (MI) patients. Microglia-mediated inflammation in the paraventricular nucleus (PVN) is involved in sympathetic hyperactivity after MI. N6-methyladenosine (m6 A), the most prevalent mRNA and epigenetic modification, is critical for mediating cell inflammation. We aimed to explore whether METTL3-mediated m6 A modification is involved in microglia-mediated sympathetic hyperactivity after MI in the PVN. MI model was established by left coronary artery ligation. METTL3-mediated m6 A modification was markedly increased in the PVN at 3 days after MI, and METTL3 was primarily located in microglia by immunofluorescence. RNA-seq, MeRIP-seq, MeRIP-qPCR, immunohistochemistry, ELISA, heart rate variability measurements, renal sympathetic nerve activity recording and programmed electrical stimulation confirmed that the elevated toll-like receptor 4 (TLR4) expression by m6 A modification on TLR4 mRNA 3'-UTR region combined with activated NF-κB signalling led to the overwhelming production of pro-inflammatory cytokines IL-1β and TNF-α in the PVN, thus inducing the sympathetic hyperactivity and increasing the incidence of VAs post-MI. Targeting METTL3 attenuated the inflammatory response and sympathetic hyperactivity and reduced the incidence of VAs post-MI.
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Affiliation(s)
- Lei Qi
- Department of Cardiology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Shandong Medicine and Health Key Laboratory of Cardiac Electrophysiology and Arrhythmia, Jinan, China.,Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, China
| | - Hui Hu
- Department of Cardiology, Jining No.1 People' Hospital, Jining, China
| | - Ye Wang
- Department of Cardiology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Shandong Medicine and Health Key Laboratory of Cardiac Electrophysiology and Arrhythmia, Jinan, China
| | - Hesheng Hu
- Department of Cardiology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Shandong Medicine and Health Key Laboratory of Cardiac Electrophysiology and Arrhythmia, Jinan, China
| | - Kang Wang
- Department of Cardiology, Shandong Qianfoshan Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Pingjiang Li
- Department of Cardiology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Shandong Medicine and Health Key Laboratory of Cardiac Electrophysiology and Arrhythmia, Jinan, China.,Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, China
| | - Jie Yin
- Department of Cardiology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Shandong Medicine and Health Key Laboratory of Cardiac Electrophysiology and Arrhythmia, Jinan, China
| | - Yugen Shi
- Department of Cardiology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Shandong Medicine and Health Key Laboratory of Cardiac Electrophysiology and Arrhythmia, Jinan, China
| | - Yu Wang
- Department of Cardiology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Shandong Medicine and Health Key Laboratory of Cardiac Electrophysiology and Arrhythmia, Jinan, China
| | - Yuepeng Zhao
- Department of Cardiology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Shandong Medicine and Health Key Laboratory of Cardiac Electrophysiology and Arrhythmia, Jinan, China.,Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, China
| | - Hangji Lyu
- Department of Cardiology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Shandong Medicine and Health Key Laboratory of Cardiac Electrophysiology and Arrhythmia, Jinan, China.,Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, China
| | - Meng Feng
- Department of Cardiology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Shandong Medicine and Health Key Laboratory of Cardiac Electrophysiology and Arrhythmia, Jinan, China.,Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, China
| | - Mei Xue
- Department of Cardiology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Shandong Medicine and Health Key Laboratory of Cardiac Electrophysiology and Arrhythmia, Jinan, China
| | - Xinran Li
- Department of Cardiology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Shandong Medicine and Health Key Laboratory of Cardiac Electrophysiology and Arrhythmia, Jinan, China
| | - Yan Li
- Medical Research Center, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Shandong Medicine and Health Key Laboratory of Cardiac Electrophysiology and Arrhythmia, Jinan, China
| | - Suhua Yan
- Department of Cardiology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Shandong Medicine and Health Key Laboratory of Cardiac Electrophysiology and Arrhythmia, Jinan, China
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5
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Oknińska M, Paterek A, Bierła J, Czarnowska E, Mączewski M, Mackiewicz U. Effect of age and sex on the incidence of ventricular arrhythmia in a rat model of acute ischemia. Biomed Pharmacother 2021; 142:111983. [PMID: 34392089 DOI: 10.1016/j.biopha.2021.111983] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/23/2021] [Accepted: 07/26/2021] [Indexed: 10/20/2022] Open
Abstract
BACKGROUND The impact of sex and age on the arrhythmic susceptibility within the setting of acute ischemia is masked by the fact that acute coronary events result from coronary artery disease appearing with age much earlier among men than among women. METHODS AND RESULTS LAD ligation or sham operations were performed in rats of both sexes at the age 3 and 24 months. An ECG was recorded continuously for 6 h after the operation. The number of early and late premature ventricular beats (PVBs), episodes of ventricular tachycardia (VT) and fibrillation (VF), heart rate, QRS, QT and Tpeak-Tend duration were analysed. Epicardial action potentials were recorded in vivo, Ca2+ signaling was evaluated in isolated cardiomyocytes, fibrosis and connexin-43 expression and localization were measured in the septum. PVBs, VT and VF episodes are much more common in older males than in young males and females independently from their age. Fibrosis with varying intensity in different muscle layers, hypertrophy of cardiomyocytes, reduced number of gap junctions and their appearance on the lateral myocyte membrane, QT prolongation, increase transmural dispersion of repolarisation and a decreased function of SERCA2a may increase the propensity to arrhythmia within the setting of acute ischemia. CONCLUSION We show that the male sex, especially in case of older individuals is a strong predictor of increased arrhythmic susceptibility within the acute ischemia setting regardless of its impact on the occurrence of cardiovascular diseases. A personalized sex-dependent prevention treatment is needed to reduce the mortality in acute phases of myocardial infarction.
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Affiliation(s)
- Marta Oknińska
- Department of Clinical Physiology, Centre of Postgraduate Medical Education, Marymoncka 99/103, 01-813 Warsaw, Poland
| | - Aleksandra Paterek
- Department of Clinical Physiology, Centre of Postgraduate Medical Education, Marymoncka 99/103, 01-813 Warsaw, Poland
| | - Joanna Bierła
- Department of Pathology, The Children's Memorial Health Institute, Aleja Dzieci Polskich 20, 04-730 Warsaw, Poland
| | - Elżbieta Czarnowska
- Department of Pathology, The Children's Memorial Health Institute, Aleja Dzieci Polskich 20, 04-730 Warsaw, Poland
| | - Michał Mączewski
- Department of Clinical Physiology, Centre of Postgraduate Medical Education, Marymoncka 99/103, 01-813 Warsaw, Poland
| | - Urszula Mackiewicz
- Department of Clinical Physiology, Centre of Postgraduate Medical Education, Marymoncka 99/103, 01-813 Warsaw, Poland.
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6
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Beta-blockers and Short-Term Cardiovascular Outcomes In Patients Hospitalized For Acute Coronary Syndrome and a Left Ventricular Ejection Fraction ≥40. Sci Rep 2020; 10:3520. [PMID: 32103115 PMCID: PMC7044295 DOI: 10.1038/s41598-020-60528-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 02/12/2020] [Indexed: 11/08/2022] Open
Abstract
Beta-blockers (BB) have been traditionally associated with improvement in cardiovascular disease outcomes in patients with ischemic cardiomyopathy. Whether they're still efficacious in the post-reperfusion era is currently debated in the light of recent controversial reports. In-hospital, 6-month and 12-month mortality were studied in the GULF-COAST, a prospective multicenter cohort of acute coronary syndrome (ACS), in relation to BB use: prior to admission, 24-hour post-admission and on discharge in patients with a left ventricular ejection fraction (LVEF) ≥ 40%. On admission, 50.9% of the cohort participants had a LVEF ≥ 40%, of whom 1203 (55.4%) were on BB whilst 905 (44.6%) were not. Mean age was 60 (13) years old and 66% were males. Prior BB use or its administration in 24 hours decreased in-hospital mortality (OR = 0.25, 95% CI [0.09-0.67]; OR = 0.16, 95% CI [0.08-0.35]; respectively). BB on discharge lowered 1-month mortality (OR = 0.28, 95% CI [0.11-0.72]), but had a neutral effect on mortality, reinfarction and stroke at 6 and 12 months. Results were unchanged after multivariable adjustments and further sensitivity analysis. In this retrospective cohort of ACS, BB improved in-hospital and 1-month mortality in patients with a LVEF ≥ 40% but had a neutral effect on longer-term outcome.
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7
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Lekkas P, Georgiou ES, Kontonika M, Mouchtouri ET, Mourouzis I, Pantos C, Kolettis TM. Intracerebroventricular endothelin receptor-A blockade in rats decreases phase-II ventricular tachyarrhythmias during acute myocardial infarction. Physiol Res 2019; 68:867-871. [PMID: 31424250 DOI: 10.33549/physiolres.934135] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Endothelin alters central sympathetic responses, but the resultant effects on arrhythmogenesis are unknown. We examined ventricular tachyarrhythmias after endothelin receptor-A blockade in the brain of Wistar rats with acute myocardial infarction. For this aim, BQ-123 (n=6) or phosphate-buffered saline (n=6) were injected intracerebroventricularly. After 10 min, the left coronary artery was ligated, followed by implantation of telemetry transmitters. Electrocardiography and voluntary activity (as a surrogate of acute left ventricular failure) were continuously monitored for 24 h. Infarct-size was similar in the two groups. There were fewer episodes of ventricular tachyarrhythmias of shorter average duration in treated rats, leading to markedly shorter total duration (12.3+/-8.9 s), when compared to controls (546.2+/-130.3 s). Voluntary activity increased in treated rats during the last hours of recording, but bradyarrhythmic episodes were comparable between the two groups. Endothelin receptor-A blockade in the brain of rats decreases the incidence of ventricular tachyarrhythmias post-ligation, without affecting bradyarrhythmic episodes. These findings call for further research on the pathophysiologic role of endothelin during acute myocardial infarction.
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Affiliation(s)
- P Lekkas
- Cardiovascular Research Institute, University of Ioannina, Ioannina, Greece.
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8
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Kolettis TM. Autonomic function and ventricular tachyarrhythmias during acute myocardial infarction. World J Exp Med 2018; 8:8-11. [PMID: 30191139 PMCID: PMC6125141 DOI: 10.5493/wjem.v8.i1.8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 08/05/2018] [Accepted: 08/21/2018] [Indexed: 02/07/2023] Open
Abstract
Most cases of sudden cardiac death are attributed to sustained ventricular tachyarrhythmias (VTs), triggered by acute coronary occlusion. Autonomic dysfunction, an important arrhythmogenic mechanism in this setting, is being actively investigated, aiming at the advent of preventive strategies. Recent experimental studies have shown vagal withdrawal after anterior myocardial infarction, coinciding with high incidence of VTs, followed by more gradual sympathetic activation coinciding with a second arrhythmia peak. This article summarizes recent knowledge on this intriguing topic, generating hypotheses that can be investigated in future experimental and clinical studies.
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Affiliation(s)
- Theofilos M Kolettis
- Department of Cardiology, Cardiovascular Research Institute and University of Ioannina Medical School, Ioannina 45500, Greece
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9
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Zhang D, Tu H, Wang C, Cao L, Muelleman RL, Wadman MC, Li YL. Correlation of Ventricular Arrhythmogenesis with Neuronal Remodeling of Cardiac Postganglionic Parasympathetic Neurons in the Late Stage of Heart Failure after Myocardial Infarction. Front Neurosci 2017; 11:252. [PMID: 28533740 PMCID: PMC5420597 DOI: 10.3389/fnins.2017.00252] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Accepted: 04/20/2017] [Indexed: 01/06/2023] Open
Abstract
Introduction: Ventricular arrhythmia is a major cause of sudden cardiac death in patients with chronic heart failure (CHF). Our recent study demonstrates that N-type Ca2+ currents in intracardiac ganglionic neurons are reduced in the late stage of CHF rats. Rat intracardiac ganglia are divided into the atrioventricular ganglion (AVG) and sinoatrial ganglion. Only AVG nerve terminals innervate the ventricular myocardium. In this study, we tested the correlation of electrical remodeling in AVG neurons with ventricular arrhythmogenesis in CHF rats. Methods and Results: CHF was induced in male Sprague-Dawley rats by surgical ligation of the left coronary artery. The data from 24-h continuous radiotelemetry ECG recording in conscious rats showed that ventricular tachycardia/fibrillation (VT/VF) occurred in 3 and 14-week CHF rats but not 8-week CHF rats. Additionally, as an index for vagal control of ventricular function, changes of left ventricular systolic pressure (LVSP) and the maximum rate of left ventricular pressure rise (LV dP/dtmax) in response to vagal efferent nerve stimulation were blunted in 14-week CHF rats but not 3 or 8-week CHF rats. Results from whole-cell patch clamp recording demonstrated that N-type Ca2+ currents in AVG neurons began to decrease in 8-week CHF rats, and that there was also a significant decrease in 14-week CHF rats. Correlation analysis revealed that N-type Ca2+ currents in AVG neurons negatively correlated with the cumulative duration of VT/VF in 14-week CHF rats, whereas there was no correlation between N-type Ca2+ currents in AVG neurons and the cumulative duration of VT/VF in 3-week CHF. Conclusion: Malignant ventricular arrhythmias mainly occur in the early and late stages of CHF. Electrical remodeling of AVG neurons highly correlates with the occurrence of ventricular arrhythmias in the late stage of CHF.
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Affiliation(s)
- Dongze Zhang
- Department of Emergency Medicine, University of Nebraska Medical CenterOmaha, NE, USA
| | - Huiyin Tu
- Department of Emergency Medicine, University of Nebraska Medical CenterOmaha, NE, USA
| | - Chaojun Wang
- Department of Emergency Medicine, University of Nebraska Medical CenterOmaha, NE, USA.,Department of Cardiovascular Disease, The First Affiliated Hospital of Xi'an Jiaotong UniversityXi'an, China
| | - Liang Cao
- Department of Emergency Medicine, University of Nebraska Medical CenterOmaha, NE, USA.,Department of Cardiac Surgery, Second Xiangya Hospital, Central South UniversityChangsha, China
| | - Robert L Muelleman
- Department of Emergency Medicine, University of Nebraska Medical CenterOmaha, NE, USA
| | - Michael C Wadman
- Department of Emergency Medicine, University of Nebraska Medical CenterOmaha, NE, USA
| | - Yu-Long Li
- Department of Emergency Medicine, University of Nebraska Medical CenterOmaha, NE, USA.,Department of Cellular & Integrative Physiology, University of Nebraska Medical CenterOmaha, NE, USA
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10
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Kolettis TM, Kontonika M, La Rocca V, Vlahos AP, Baltogiannis GG, Kyriakides ZS. Local conduction during acute myocardial infarction in rats: Interplay between central sympathetic activation and endothelin. J Arrhythm 2016; 33:144-146. [PMID: 28416983 PMCID: PMC5388042 DOI: 10.1016/j.joa.2016.07.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 06/23/2016] [Accepted: 07/19/2016] [Indexed: 01/01/2023] Open
Abstract
We investigated the effects of autonomic dysfunction and endothelin on local conduction and arrhythmogenesis during myocardial infarction. We recorded ventricular tachyarrhythmias, monophasic action potentials, and activation sequences in wild-type and ETB-deficient rats displaying high endothelin levels. Central sympathetic inputs were examined after clonidine administration. Clonidine mitigated early and delayed arrhythmogenesis in ETB-deficient and wild-type rats, respectively. The right ventricular activation delay increased in clonidine-treated ETB-deficient rats and slightly decreased in wild-type rats. The left ventricular voltage rise decreased in all groups, whereas the activation delay increased mainly in clonidine-treated ETB-deficient rats. Central sympathetic activation and endothelin modulate ischemia-induced arrhythmogenesis. Ischemia alters excitability, whereas endothelin impairs local conduction, an action partly counterbalanced by central sympathetic activity.
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Affiliation(s)
- Theofilos M Kolettis
- Cardiovascular Research Institute, 1 Stavrou Niarxou Ave., 45500 Ioannina, Greece
| | - Marianthi Kontonika
- Cardiovascular Research Institute, 1 Stavrou Niarxou Ave., 45500 Ioannina, Greece
| | - Vassilios La Rocca
- Cardiovascular Research Institute, 1 Stavrou Niarxou Ave., 45500 Ioannina, Greece
| | - Antonios P Vlahos
- Cardiovascular Research Institute, 1 Stavrou Niarxou Ave., 45500 Ioannina, Greece
| | | | - Zenon S Kyriakides
- Cardiovascular Research Institute, 1 Stavrou Niarxou Ave., 45500 Ioannina, Greece
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11
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Effects of central sympathetic activation on repolarization-dispersion during short-term myocardial ischemia in anesthetized rats. Life Sci 2015; 144:170-7. [PMID: 26679103 DOI: 10.1016/j.lfs.2015.12.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Revised: 11/08/2015] [Accepted: 12/07/2015] [Indexed: 12/28/2022]
Abstract
AIMS Sympathetic activation during myocardial ischemia enhances arrhythmogenesis, but the underlying pathophysiologic mechanisms remain unclear. We investigated the central sympathetic effects on ventricular repolarization during the early-period post-coronary artery occlusion. MAIN METHODS We studied 12 Wistar rats (254±2 g) for 30 min following left coronary artery ligation, with (n=6) or without (n=6) pretreatment with the central sympatholytic agent clonidine. Mapping of left and right ventricular epicardial electrograms was performed with a 32-electrode array. As an index of sympathetic activation, heart rate variability in the frequency domain was calculated. Heart rate and repolarization duration were measured with a custom-made recording and analysis software, followed by calculation of intra- and inter-ventricular dispersion of repolarization. KEY FINDINGS Heart rate and heart rate variability indicated lower sympathetic activation in clonidine-treated rats during ischemia. Repolarization duration in the left ventricle prolonged after clonidine at baseline, independently of heart rate, but no differences were present 30 min post-ligation. Dispersion of repolarization in the right ventricle remained stable during ischemia, whereas it increased in the left ventricle, equally in both groups. A similar trend was observed for inter-ventricular dispersion, without differences between groups. SIGNIFICANCE In addition to intra-ventricular repolarization-dispersion, anterior-wall myocardial ischemia may also increase inter-ventricular repolarization-dispersion. Progressive central sympathetic activation occurs during myocardial ischemia, but it does not affect intra- or inter-ventricular dispersion of ventricular repolarization during the early phase. Further research is warranted on the potential effects during subsequent time-periods.
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