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Li P, Kim JK. Circadian regulation of sinoatrial nodal cell pacemaking function: Dissecting the roles of autonomic control, body temperature, and local circadian rhythmicity. PLoS Comput Biol 2024; 20:e1011907. [PMID: 38408116 PMCID: PMC10927146 DOI: 10.1371/journal.pcbi.1011907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 03/11/2024] [Accepted: 02/12/2024] [Indexed: 02/28/2024] Open
Abstract
Strong circadian (~24h) rhythms in heart rate (HR) are critical for flexible regulation of cardiac pacemaking function throughout the day. While this circadian flexibility in HR is sustained in diverse conditions, it declines with age, accompanied by reduced maximal HR performance. The intricate regulation of circadian HR involves the orchestration of the autonomic nervous system (ANS), circadian rhythms of body temperature (CRBT), and local circadian rhythmicity (LCR), which has not been fully understood. Here, we developed a mathematical model describing ANS, CRBT, and LCR in sinoatrial nodal cells (SANC) that accurately captures distinct circadian patterns in adult and aged mice. Our model underscores how the alliance among ANS, CRBT, and LCR achieves circadian flexibility to cover a wide range of firing rates in SANC, performance to achieve maximal firing rates, while preserving robustness to generate rhythmic firing patterns irrespective of external conditions. Specifically, while ANS dominates in promoting SANC flexibility and performance, CRBT and LCR act as primary and secondary boosters, respectively, to further enhance SANC flexibility and performance. Disruption of this alliance with age results in impaired SANC flexibility and performance, but not robustness. This unexpected outcome is primarily attributed to the age-related reduction in parasympathetic activities, which maintains SANC robustness while compromising flexibility. Our work sheds light on the critical alliance of ANS, CRBT, and LCR in regulating time-of-day cardiac pacemaking function and dysfunction, offering insights into novel therapeutic targets for the prevention and treatment of cardiac arrhythmias.
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Affiliation(s)
- Pan Li
- Biomedical Mathematics Group, Pioneer Research Center for Mathematical and Computational Sciences, Institute for Basic Science, Daejeon, Republic of Korea
| | - Jae Kyoung Kim
- Biomedical Mathematics Group, Pioneer Research Center for Mathematical and Computational Sciences, Institute for Basic Science, Daejeon, Republic of Korea
- Department of Mathematical Sciences, KAIST, Daejeon, Republic of Korea
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2
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Goodman MO, Dashti HS, Lane JM, Windred DP, Burns A, Jones SE, Sofer T, Purcell SM, Zhu X, Ollila HM, Kyle SD, Spiegelhalder K, Peker Y, Huang T, Cain SW, Phillips AJK, Saxena R, Rutter MK, Redline S, Wang H. Causal Association Between Subtypes of Excessive Daytime Sleepiness and Risk of Cardiovascular Diseases. J Am Heart Assoc 2023; 12:e030568. [PMID: 38084713 PMCID: PMC10863774 DOI: 10.1161/jaha.122.030568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 10/03/2023] [Indexed: 12/20/2023]
Abstract
BACKGROUND Excessive daytime sleepiness (EDS), experienced in 10% to 20% of the population, has been associated with cardiovascular disease and death. However, the condition is heterogeneous and is prevalent in individuals having short and long sleep duration. We sought to clarify the relationship between sleep duration subtypes of EDS with cardiovascular outcomes, accounting for these subtypes. METHODS AND RESULTS We defined 3 sleep duration subtypes of excessive daytime sleepiness: normal (6-9 hours), short (<6 hours), and long (>9 hours), and compared these with a nonsleepy, normal-sleep-duration reference group. We analyzed their associations with incident myocardial infarction (MI) and stroke using medical records of 355 901 UK Biobank participants and performed 2-sample Mendelian randomization for each outcome. Compared with healthy sleep, long-sleep EDS was associated with an 83% increased rate of MI (hazard ratio, 1.83 [95% CI, 1.21-2.77]) during 8.2-year median follow-up, adjusting for multiple health and sociodemographic factors. Mendelian randomization analysis provided supporting evidence of a causal role for a genetic long-sleep EDS subtype in MI (inverse-variance weighted β=1.995, P=0.001). In contrast, we did not find evidence that other subtypes of EDS were associated with incident MI or any associations with stroke (P>0.05). CONCLUSIONS Our study suggests the previous evidence linking EDS with increased cardiovascular disease risk may be primarily driven by the effect of its long-sleep subtype on higher risk of MI. Underlying mechanisms remain to be investigated but may involve sleep irregularity and circadian disruption, suggesting a need for novel interventions in this population.
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Affiliation(s)
- Matthew O. Goodman
- Division of Sleep and Circadian DisordersBrigham and Women’s HospitalBostonMA
- Department of Neurology and MedicineHarvard Medical School, Brigham and Women’s HospitalBostonMA
- Broad InstituteCambridgeMA
| | - Hassan S. Dashti
- Broad InstituteCambridgeMA
- Center for Genomic MedicineMassachusetts General Hospital and Harvard Medical SchoolBostonMA
- Department of Anesthesia, Critical Care and Pain MedicineMassachusetts General HospitalBostonMA
| | - Jacqueline M. Lane
- Division of Sleep and Circadian DisordersBrigham and Women’s HospitalBostonMA
- Department of Neurology and MedicineHarvard Medical School, Brigham and Women’s HospitalBostonMA
- Broad InstituteCambridgeMA
- Center for Genomic MedicineMassachusetts General Hospital and Harvard Medical SchoolBostonMA
| | - Daniel P. Windred
- School of Psychological SciencesTurner Institute for Brain and Mental Health, Monash UniversityMelbourneVictoriaAustralia
| | - Angus Burns
- Broad InstituteCambridgeMA
- Center for Genomic MedicineMassachusetts General Hospital and Harvard Medical SchoolBostonMA
- School of Psychological SciencesTurner Institute for Brain and Mental Health, Monash UniversityMelbourneVictoriaAustralia
| | - Samuel E. Jones
- Institute for Molecular Medicine Finland (FIMM)University of HelsinkiFinland
- University of Exeter Medical SchoolExeterUnited Kingdom
| | - Tamar Sofer
- Division of Sleep and Circadian DisordersBrigham and Women’s HospitalBostonMA
- Department of Neurology and MedicineHarvard Medical School, Brigham and Women’s HospitalBostonMA
- Department of BiostatisticsHarvard T.H. Chan School of Public HealthBostonMA
| | - Shaun M. Purcell
- Division of Sleep and Circadian DisordersBrigham and Women’s HospitalBostonMA
- Department of Neurology and MedicineHarvard Medical School, Brigham and Women’s HospitalBostonMA
- Broad InstituteCambridgeMA
- Department of PsychiatryBrigham and Women’s HospitalBostonMA
| | - Xiaofeng Zhu
- Department of Population and Quantitative Health SciencesCase Western Reserve UniversityClevelandOH
| | - Hanna M. Ollila
- Broad InstituteCambridgeMA
- Center for Genomic MedicineMassachusetts General Hospital and Harvard Medical SchoolBostonMA
- Department of Anesthesia, Critical Care and Pain MedicineMassachusetts General HospitalBostonMA
- Institute for Molecular Medicine Finland (FIMM)University of HelsinkiFinland
| | - Simon D. Kyle
- Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical NeurosciencesUniversity of OxfordUnited Kingdom
| | - Kai Spiegelhalder
- Department of Psychiatry and PsychotherapyMedical Centre–University of Freiburg, Faculty of Medicine, University of FreiburgFreiburgGermany
| | - Yuksel Peker
- Division of Sleep and Circadian DisordersBrigham and Women’s HospitalBostonMA
- Department of Neurology and MedicineHarvard Medical School, Brigham and Women’s HospitalBostonMA
- Department of Pulmonary MedicineKoç University School of MedicineIstanbulTurkey
- Sahlgrenska AcademyUniversity of GothenburgSweden
- Department of Clinical Sciences, Respiratory Medicine and Allergology, Faculty of MedicineLund UniversityLundSweden
- Division of Pulmonary, Allergy, and Critical Care MedicineUniversity of Pittsburgh School of MedicinePittsburghPA
| | - Tianyi Huang
- Department of Neurology and MedicineHarvard Medical School, Brigham and Women’s HospitalBostonMA
- Channing Division of Network MedicineBrigham and Women’s Hospital, Harvard Medical SchoolBostonMA
| | - Sean W. Cain
- School of Psychological SciencesTurner Institute for Brain and Mental Health, Monash UniversityMelbourneVictoriaAustralia
| | - Andrew J. K. Phillips
- School of Psychological SciencesTurner Institute for Brain and Mental Health, Monash UniversityMelbourneVictoriaAustralia
| | - Richa Saxena
- Broad InstituteCambridgeMA
- Center for Genomic MedicineMassachusetts General Hospital and Harvard Medical SchoolBostonMA
- Department of Anesthesia, Critical Care and Pain MedicineMassachusetts General HospitalBostonMA
| | - Martin K. Rutter
- Division of Endocrinology, Diabetes & Gastroenterology, School of Medical Sciences, Faculty of Biology, Medicine and HealthUniversity of ManchesterManchesterUnited Kingdom
- Diabetes, Endocrinology and Metabolism CentreManchester University NHS Foundation Trust, NIHR Manchester Biomedical Research Centre, Manchester Academic Health Science CentreManchesterUnited Kingdom
| | - Susan Redline
- Division of Sleep and Circadian DisordersBrigham and Women’s HospitalBostonMA
- Department of Neurology and MedicineHarvard Medical School, Brigham and Women’s HospitalBostonMA
| | - Heming Wang
- Division of Sleep and Circadian DisordersBrigham and Women’s HospitalBostonMA
- Department of Neurology and MedicineHarvard Medical School, Brigham and Women’s HospitalBostonMA
- Broad InstituteCambridgeMA
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3
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Weiser-Bitoun I, Mori H, Nabeshima T, Tanaka N, Kudo D, Sasaki W, Narita M, Matsumoto K, Ikeda Y, Arai T, Nakano S, Sumitomo N, Senbonmatsu TA, Matsumoto K, Kato R, Morrell CH, Tsutsui K, Yaniv Y. Age-dependent contribution of intrinsic mechanisms to sinoatrial node function in humans. Sci Rep 2023; 13:18875. [PMID: 37914708 PMCID: PMC10620402 DOI: 10.1038/s41598-023-45101-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 10/16/2023] [Indexed: 11/03/2023] Open
Abstract
Average beat interval (BI) and beat interval variability (BIV) are primarily determined by mutual entrainment between the autonomic-nervous system (ANS) and intrinsic mechanisms that govern sinoatrial node (SAN) cell function. While basal heart rate is not affected by age in humans, age-dependent reductions in intrinsic heart rate have been documented even in so-called healthy individuals. The relative contributions of the ANS and intrinsic mechanisms to age-dependent deterioration of SAN function in humans are not clear. We recorded ECG on patients (n = 16 < 21 years and n = 23 41-78 years) in the basal state and after ANS blockade (propranolol and atropine) in the presence of propofol and dexmedetomidine anesthesia. Average BI and BIV were analyzed. A set of BIV features were tested to designated the "signatures" of the ANS and intrinsic mechanisms and also the anesthesia "signature". In young patients, the intrinsic mechanisms and ANS mainly contributed to long- and short-term BIV, respectively. In adults, both ANS and intrinsic mechanisms contributed to short-term BIV, while the latter also contributed to long-term BIV. Furthermore, anesthesia affected ANS function in young patients and both mechanisms in adult. The work also showed that intrinsic mechanism features can be calculated from BIs, without intervention.
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Affiliation(s)
- Ido Weiser-Bitoun
- Faculty of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
- Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Hitoshi Mori
- Saitama Medical University International Medical Center, Saitama, Japan
| | - Taisuke Nabeshima
- Saitama Medical University International Medical Center, Saitama, Japan
| | - Naomichi Tanaka
- Saitama Medical University International Medical Center, Saitama, Japan
| | - Daisuke Kudo
- Saitama Medical University International Medical Center, Saitama, Japan
| | - Wataru Sasaki
- Saitama Medical University International Medical Center, Saitama, Japan
| | - Masataka Narita
- Saitama Medical University International Medical Center, Saitama, Japan
| | | | - Yoshifumi Ikeda
- Saitama Medical University International Medical Center, Saitama, Japan
| | - Takahide Arai
- Saitama Medical University International Medical Center, Saitama, Japan
| | - Shintaro Nakano
- Saitama Medical University International Medical Center, Saitama, Japan
| | - Naokata Sumitomo
- Saitama Medical University International Medical Center, Saitama, Japan
| | | | - Kazuo Matsumoto
- Saitama Medical University International Medical Center, Saitama, Japan
| | - Ritsushi Kato
- Saitama Medical University International Medical Center, Saitama, Japan
| | - Christopher H Morrell
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Kenta Tsutsui
- Saitama Medical University International Medical Center, Saitama, Japan.
- Department of Cardiovascular Medicine, Saitama Medical University International Medical Center, Saitama, Japan.
| | - Yael Yaniv
- Faculty of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel.
- Laboratory of Bioenergetic and Bioelectric Systems, The Faculty of Biomedical Engineering Technion-IIT, Haifa, Israel.
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4
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Morelli D, Rossi A, Bartoloni L, Cairo M, Clifton DA. SDNN24 Estimation from Semi-Continuous HR Measures. SENSORS (BASEL, SWITZERLAND) 2021; 21:1463. [PMID: 33672456 PMCID: PMC7923410 DOI: 10.3390/s21041463] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/12/2021] [Accepted: 02/15/2021] [Indexed: 12/31/2022]
Abstract
The standard deviation of the interval between QRS complexes recorded over 24 h (SDNN24) is an important metric of cardiovascular health. Wrist-worn fitness wearable devices record heart beats 24/7 having a complete overview of users' heart status. Due to motion artefacts affecting QRS complexes recording, and the different nature of the heart rate sensor used on wearable devices compared to ECG, traditionally used to compute SDNN24, the estimation of this important Heart Rate Variability (HRV) metric has never been performed from wearable data. We propose an innovative approach to estimate SDNN24 only exploiting the Heart Rate (HR) that is normally available on wearable fitness trackers and less affected by data noise. The standard deviation of inter-beats intervals (SDNN24) and the standard deviation of the Average inter-beats intervals (ANN) derived from the HR (obtained in a time window with defined duration, i.e., 1, 5, 10, 30 and 60 min), i.e., ANN=60HR (SDANNHR24), were calculated over 24 h. Power spectrum analysis using the Lomb-Scargle Peridogram was performed to assess frequency domain HRV parameters (Ultra Low Frequency, Very Low Frequency, Low Frequency, and High Frequency). Due to the fact that SDNN24 reflects the total power of the power of the HRV spectrum, the values estimated from HR measures (SDANNHR24) underestimate the real values because of the high frequencies that are missing. Subjects with low and high cardiovascular risk show different power spectra. In particular, differences are detected in Ultra Low and Very Low frequencies, while similar results are shown in Low and High frequencies. For this reason, we found that HR measures contain enough information to discriminate cardiovascular risk. Semi-continuous measures of HR throughout 24 h, as measured by most wrist-worn fitness wearable devices, should be sufficient to estimate SDNN24 and cardiovascular risk.
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Affiliation(s)
- Davide Morelli
- Huma Therapeutics Limited, London SW1P 4QP, UK; (L.B.); (M.C.)
- Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford OX1 2JD, UK;
| | - Alessio Rossi
- Department of Computer Science, University of Pisa, 56126 Pisa, Italy;
| | | | - Massimo Cairo
- Huma Therapeutics Limited, London SW1P 4QP, UK; (L.B.); (M.C.)
| | - David A. Clifton
- Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford OX1 2JD, UK;
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5
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Monfredi O, Lakatta EG. Complexities in cardiovascular rhythmicity: perspectives on circadian normality, ageing and disease. Cardiovasc Res 2020; 115:1576-1595. [PMID: 31150049 DOI: 10.1093/cvr/cvz112] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 02/06/2019] [Accepted: 05/25/2019] [Indexed: 12/13/2022] Open
Abstract
Biological rhythms exist in organisms at all levels of complexity, in most organs and at myriad time scales. Our own biological rhythms are driven by energy emitted by the sun, interacting via our retinas with brain stem centres, which then send out complex messages designed to synchronize the behaviour of peripheral non-light sensing organs, to ensure optimal physiological responsiveness and performance of the organism based on the time of day. Peripheral organs themselves have autonomous rhythmic behaviours that can act independently from central nervous system control but is entrainable. Dysregulation of biological rhythms either through environment or disease has far-reaching consequences on health that we are only now beginning to appreciate. In this review, we focus on cardiovascular rhythms in health, with ageing and under disease conditions.
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Affiliation(s)
- Oliver Monfredi
- Division of Medicine, Department of Cardiology, The Johns Hopkins Hospital, 1800 Orleans Street, Baltimore, MD, USA.,Laboratory of Cardiovascular Sciences, Intramural Research Program, National Institute on Aging, National Institutes of Health, 251 Bayview Blvd, Baltimore, MD, USA
| | - Edward G Lakatta
- Laboratory of Cardiovascular Sciences, Intramural Research Program, National Institute on Aging, National Institutes of Health, 251 Bayview Blvd, Baltimore, MD, USA
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6
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Signatures of the autonomic nervous system and the heart's pacemaker cells in canine electrocardiograms and their applications to humans. Sci Rep 2020; 10:9971. [PMID: 32561798 PMCID: PMC7305326 DOI: 10.1038/s41598-020-66709-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 03/13/2020] [Indexed: 01/21/2023] Open
Abstract
Heart rate and heart rate variability (HRV) are mainly determined by the autonomic nervous system (ANS), which interacts with receptors on the sinoatrial node (SAN; the heart’s primary pacemaker), and by the “coupled-clock” system within the SAN cells. HRV changes are associated with cardiac diseases. However, the relative contributions of the ANS and SAN to HRV are not clear, impeding effective treatment. To discern the SAN’s contribution, we performed HRV analysis on canine electrocardiograms containing basal and ANS-blockade segments. We also analyzed human electrocardiograms of atrial fibrillation and heart failure patients, as well as healthy aged subjects. Finally, we used a mathematical model to simulate HRV under decreased “coupled-clock” regulation. We found that (a) in canines, the SAN and ANS contribute mainly to long- and short-term HRV, respectively; (b) there is evidence suggesting a similar relative SAN contribution in humans; (c) SAN features can be calculated from beat-intervals obtained in-vivo, without intervention; (d) ANS contribution can be modeled by sines embedded in white noise; (e) HRV changes associated with cardiac diseases and aging can be interpreted as deterioration of both SAN and ANS; and (f) SAN clock-coupling can be estimated from changes in HRV. This may enable future non-invasive diagnostic applications.
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7
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Catai AM, Pastre CM, Godoy MFD, Silva ED, Takahashi ACDM, Vanderlei LCM. Heart rate variability: are you using it properly? Standardisation checklist of procedures. Braz J Phys Ther 2019; 24:91-102. [PMID: 30852243 DOI: 10.1016/j.bjpt.2019.02.006] [Citation(s) in RCA: 152] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 02/11/2019] [Accepted: 02/14/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Heart rate variability is used as an assessment method for cardiac autonomic modulation. Since the Task Force's publication on heart rate variability in 1996, the European Heart Rhythm Association Position Paper in 2015 and a recent publication in 2017, attention has been paid to recommendations on using heart rate variability analysis methods, as well as their applications in different physiological conditions and clinical studies. This analysis has proved to be useful as a complementary tool for clinical evaluation and to assess the effect of non-pharmacological therapeutic interventions, such as physical exercise programmes, on cardiac autonomic modulation. OBJECTIVE The aim of this article is to make recommendations and to develop a checklist of normalisation procedures regarding the use of heart rate variability data collection and analysis methodology, focusing on the cardiology area and cardiac rehabilitation. METHODS Based on previous heart rate variability publications, this paper provides a description of the most common shortcomings of using the analysis methods and considers recommendations and suggestions on how to minimise these occurrences by using a specific checklist. CONCLUSIONS This article includes recommendations and a checklist regarding the use of heart rate variability collection and analysis methods. This work could help improve reporting on clinical evaluation and therapeutic intervention results and consequently, disseminate heart rate variability knowledge.
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Affiliation(s)
- Aparecida Maria Catai
- Cardiovascular Physical Therapy Laboratory, Department of Physical Therapy, Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil.
| | - Carlos Marcelo Pastre
- School of Technology and Sciences, São Paulo State University (UNESP), Presidente Prudente, SP, Brazil
| | - Moacir Fernades de Godoy
- Department of Cardiology and Cardiovascular Surgery, Faculdade de Medicina de São José do Rio Preto (FAMERP), São José do Rio Preto, SP, Brazil
| | - Ester da Silva
- Cardiovascular Physical Therapy Laboratory, Department of Physical Therapy, Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil
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8
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Karimi F, Rafati A, Noorafshan A, Hosseini L, Karbalay-Doust S. Sinoatrial node remodels in chronic sleep-restricted rats. Chronobiol Int 2019; 36:510-516. [PMID: 30676106 DOI: 10.1080/07420528.2018.1563900] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Chronic Sleep Restriction (CSR) is known as a risk factor for cardiovascular diseases. However, the structural changes of Sinoatrial (SA) node cells have received less attention. This study aimed to evaluate the effects of CSR on SA node in an animal model using stereological methods. Adult male Sprague-Dawley rats were randomly divided into CSR, grid-floor, and control groups. The CSR procedure was designed such a way that the animals had a full cycle of sleep (6 hours) per day, while they were unable to have a Rapid Eye Movement (REM) sleep during the remaining 18 hours. This was induced by a multiplatform box containing water. The grid-floor animals were placed in the same multiplatform box with a grid-floor covering to prevent falling in water. After 21 days, the right atria were dissected out. Then, the location of the SA node was determined and evaluated by stereological techniques. The total volume of the SA node, the total volume of the main node cells, the volume of the connective tissue, and mean volume of the node cells were respectively enlarged by 60%, 47%, 68%, and 51% in the CSR animals compared to the grid-floor rats (p < 0.05). However, no significant changes were detected in these parameters in the control and grid-floor animals. The population of the main node cells remained constant in all animal groups. In addition, the three-dimensional reconstruction of the SA node in the CSR group showed a hypertrophied appearance. In conclusion, CSR induced hypertrophic changes in the rats' SA node structures without alteration in the number of main node cells.
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Affiliation(s)
- Fatemeh Karimi
- a Histomorphometry and Stereology Research Center , Shiraz University of Medical Sciences , Shiraz , Iran.,b Department of Anatomy , Shiraz University of Medical Sciences , Shiraz , Iran
| | - Ali Rafati
- a Histomorphometry and Stereology Research Center , Shiraz University of Medical Sciences , Shiraz , Iran.,c Department of Physiology , Shiraz University of Medical Sciences , Shiraz , Iran
| | - Ali Noorafshan
- a Histomorphometry and Stereology Research Center , Shiraz University of Medical Sciences , Shiraz , Iran.,b Department of Anatomy , Shiraz University of Medical Sciences , Shiraz , Iran
| | - Leila Hosseini
- d Department of Traditional Medicine , School of Medicine, Shiraz University of Medical Sciences , Shiraz , Iran
| | - Saied Karbalay-Doust
- a Histomorphometry and Stereology Research Center , Shiraz University of Medical Sciences , Shiraz , Iran.,b Department of Anatomy , Shiraz University of Medical Sciences , Shiraz , Iran
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9
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Very Low Frequency Heart Rate Variability Predicts the Development of Post-Stroke Infections. Transl Stroke Res 2019; 10:607-619. [DOI: 10.1007/s12975-018-0684-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 12/03/2018] [Accepted: 12/28/2018] [Indexed: 10/27/2022]
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10
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Täubel J, Ferber G, Fernandes S, Camm AJ. Diurnal Profile of the QTc Interval Following Moxifloxacin Administration. J Clin Pharmacol 2018; 59:35-44. [PMID: 30040135 DOI: 10.1002/jcph.1283] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 06/21/2018] [Indexed: 12/13/2022]
Abstract
Understanding the physiological fluctuations in the corrected QT (QTc) interval is important to accurately interpret the variations in drug-induced prolongation. The present study aimed to define the time course of the effect of moxifloxacin on the QT interval to understand the duration of the responses to moxifloxacin. This retrospective analysis was performed on data taken from a thorough QT 4-way crossover study with 40 subjects. Each period consisted of a baseline electrocardiogram (ECG) day (day -1) and a treatment day (day 1). On both days, ECGs were recorded simultaneously using 2 different systems operating in parallel: a bedside ECG and a continuous Holter recording. The subjects were randomized to 1 of 4 treatments: 5 mg and 40 mg of intravenous amisulpride, a single oral dose of moxifloxacin (400 mg), or placebo. Standardized meals, identical in all 4 periods, with similar nutritional value were served. Bedside ECG results confirmed that the moxifloxacin peak effect was delayed in the fed state and showed that the Fridericia corrected QT prolongation induced by moxifloxacin persisted until the end of the 24-hour measurement period. The use of continuous Holter monitoring provided further insight, as it revealed that the moxifloxacin effect on QTc was influenced by diurnal and nocturnal environmental factors, and hysteresis effects were noticeable. The findings suggested that moxifloxacin prolongs QTc beyond its elimination from the blood circulation. This is of relevance to current concentration-effect modeling approaches, which presume the absence of hysteresis effects.
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Affiliation(s)
- Jörg Täubel
- Richmond Pharmacology Ltd., St George's University of London, London, UK.,Cardiovascular and Cell Sciences Research Institute, St George's University of London, London, UK
| | - Georg Ferber
- Statistik Georg Ferber GmbH, Riehen, Switzerland
| | - Sara Fernandes
- Richmond Pharmacology Ltd., St George's University of London, London, UK
| | - A John Camm
- Cardiovascular and Cell Sciences Research Institute, St George's University of London, London, UK
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11
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Wang Q, Cui Y, Yogendranath P, Wang N. Blood pressure and heart rate variability are linked with hyperphosphatemia in chronic kidney disease patients. Chronobiol Int 2018; 35:1329-1334. [PMID: 29947550 DOI: 10.1080/07420528.2018.1486850] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Hyperphosphatemia is a common complication of chronic kidney disease (CKD) and is associated with cardiovascular disease (CVD), which has contributed to an increase in mortality of CKD patients. The onset of CVD often varies by time-of-day. Acute myocardial infarction or ventricular arrhythmia occurs most frequently during early morning. Blood pressure (BP) and heart rate circadian rhythms account for the diurnal variations in CVD. Preservation of normal circadian time structure from the cardiomyocyte level to the whole organ system is essential for cardiovascular health and CVD prevention. Independent risk factors, such as reduced heart rate variability (HRV) and increased BP variability (BPV), are particularly prevalent in patients with CKD. Analysis of HRV is an important clinical tool for characterizing cardiac autonomic status, and reduced HRV has prognostic significance for various types of CVD. Circadian BP rhythms are classified as extreme dipper, dipper, non-dipper or riser. It has been reported that nocturnal riser BP pattern contributes to cardiovascular threats. Previous studies have indicated that the circadian rhythm of serum phosphate in CKD patients is consistent with the general population, with the highest diurnal value observed in the early morning hours, followed by a progressive decrease to the lowest value of the day, which occurs around 11:00 am. Rhythm abnormalities have become the main therapeutic target for treating CVD in CKD patients. It has been reported that high levels of serum phosphate are associated with reduced HRV and increased BPV in CKD patients. However, the mechanisms related to interactions between hyperphosphatemia, HRV and BPV have not been fully elucidated. This review focuses on the evidence and discusses the potential mechanisms related to the effects of hyperphosphatemia on HRV and BPV.
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Affiliation(s)
- Qingting Wang
- a Department of Nephrology , the First Affiliated Hospital of Nanjing Medical University , Nanjing , China
| | - Ying Cui
- a Department of Nephrology , the First Affiliated Hospital of Nanjing Medical University , Nanjing , China
| | - Purrunsing Yogendranath
- a Department of Nephrology , the First Affiliated Hospital of Nanjing Medical University , Nanjing , China
| | - Ningning Wang
- a Department of Nephrology , the First Affiliated Hospital of Nanjing Medical University , Nanjing , China
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Kozasa Y, Nakashima N, Ito M, Ishikawa T, Kimoto H, Ushijima K, Makita N, Takano M. HCN4 pacemaker channels attenuate the parasympathetic response and stabilize the spontaneous firing of the sinoatrial node. J Physiol 2018; 596:809-825. [PMID: 29315578 PMCID: PMC5830425 DOI: 10.1113/jp275303] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Accepted: 01/02/2018] [Indexed: 01/01/2023] Open
Abstract
Key points The contribution of HCN4 pacemaker channels in the autonomic regulation of the sino‐atrial node (SAN) has been a matter of debate. The transgenic overexpression of HCN4 did not induce tachycardia, but reduced heart rate variability, while the conditional knockdown of HCN4 gave rise to sinus arrhythmia. The response of the SAN to β‐adrenergic stimulation was not affected by overexpression or knockdown of HCN4 channels. When HCN4 channels were knocked down, the parasympathetic response examined by cervical vagus nerve stimulation (CVNS) was enhanced; the CVNS induced complete sinus pause. The overexpression of HCN4 attenuated bradycardia induced by CVNS only during β‐adrenergic stimulation. We concluded that HCN4 pacemaker channels stabilize the spontaneous firing by attenuating the parasympathetic response of the SAN.
Abstract The heart rate is dynamically controlled by the sympathetic and parasympathetic nervous systems that regulate the sinoatrial node (SAN). HCN4 pacemaker channels are the well‐known causative molecule of congenital sick sinus syndrome. Although HCN4 channels are activated by cAMP, the sympathetic response of the SAN was preserved in patients carrying loss‐of‐function mutations of the HCN4 gene. In order to clarify the contribution of HCN4 channels in the autonomic regulation of the SAN, we developed novel gain‐of‐function mutant mice in which the expression level of HCN4 channels could be reversibly changed from zero to ∼3 times that in wild‐type mice, using tetracycline transactivator and the tetracycline responsive element. We recorded telemetric ECGs in freely moving conscious mice and analysed the heart rate variability. We also evaluated the response of the SAN to cervical vagus nerve stimulation (CVNS). The conditional overexpression of HCN4 did not induce tachycardia, but reduced heart rate variability. The HCN4 overexpression also attenuated bradycardia induced by the CVNS only during the β‐adrenergic stimulation. In contrast, the knockdown of HCN4 gave rise to sinus arrhythmia, and enhanced the parasympathetic response; complete sinus pause was induced by the CVNS. In vitro, we compared the effects of acetylcholine on the spontaneous action potentials of single pacemaker cells, and found that similar phenotypic changes were induced by genetic manipulation of HCN4 expression both in the presence and absence of β‐adrenergic stimulation. Our study suggests that HCN4 channels attenuate the vagal response of the SAN, and thereby stabilize the spontaneous firing of the SAN. The contribution of HCN4 pacemaker channels in the autonomic regulation of the sino‐atrial node (SAN) has been a matter of debate. The transgenic overexpression of HCN4 did not induce tachycardia, but reduced heart rate variability, while the conditional knockdown of HCN4 gave rise to sinus arrhythmia. The response of the SAN to β‐adrenergic stimulation was not affected by overexpression or knockdown of HCN4 channels. When HCN4 channels were knocked down, the parasympathetic response examined by cervical vagus nerve stimulation (CVNS) was enhanced; the CVNS induced complete sinus pause. The overexpression of HCN4 attenuated bradycardia induced by CVNS only during β‐adrenergic stimulation. We concluded that HCN4 pacemaker channels stabilize the spontaneous firing by attenuating the parasympathetic response of the SAN.
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Affiliation(s)
- Yuko Kozasa
- Department of Physiology, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, 830-0011, Japan.,Department of Anesthesiology, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, 830-0011, Japan
| | - Noriyuki Nakashima
- Department of Physiology, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, 830-0011, Japan
| | - Masayuki Ito
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan
| | - Taisuke Ishikawa
- Department of Molecular Physiology, Nagasaki University, Graduate School of Biomedical Sciences, 1-12-4, Sakamoto, Nagasaki, 852-8523, Japan
| | - Hiroki Kimoto
- Department of Molecular Physiology, Nagasaki University, Graduate School of Biomedical Sciences, 1-12-4, Sakamoto, Nagasaki, 852-8523, Japan
| | - Kazuo Ushijima
- Department of Anesthesiology, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, 830-0011, Japan
| | - Naomasa Makita
- Department of Molecular Physiology, Nagasaki University, Graduate School of Biomedical Sciences, 1-12-4, Sakamoto, Nagasaki, 852-8523, Japan
| | - Makoto Takano
- Department of Physiology, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, 830-0011, Japan
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The Effects of Pharmacological Compounds on Beat Rate Variations in Human Long QT-Syndrome Cardiomyocytes. Stem Cell Rev Rep 2017; 12:698-707. [PMID: 27646833 PMCID: PMC5106508 DOI: 10.1007/s12015-016-9686-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Healthy human heart rate fluctuates overtime showing long-range fractal correlations. In contrast, various cardiac diseases and normal aging show the breakdown of fractal complexity. Recently, it was shown that human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) intrinsically exhibit fractal behavior as in humans. Here, we investigated the fractal complexity of hiPSC-derived long QT-cardiomyocytes (LQT-CMs). We recorded extracellular field potentials from hiPSC-CMs at baseline and under the effect of various compounds including β-blocker bisoprolol, ML277, a specific and potent IKs current activator, as well as JNJ303, a specific IKs blocker. From the peak-to-peak-intervals, we determined the long-range fractal correlations by using detrended fluctuation analysis. Electrophysiologically, the baseline corrected field potential durations (cFPDs) were more prolonged in LQT-CMs than in wildtype (WT)-CMs. Bisoprolol did not have significant effects to the cFPD in any CMs. ML277 shortened cFPD in a dose-dependent fashion by 11 % and 5–11 % in WT- and LQT-CMs, respectively. JNJ303 prolonged cFPD in a dose-dependent fashion by 22 % and 7–13 % in WT- and LQT-CMs, respectively. At baseline, all CMs showed fractal correlations as determined by short-term scaling exponent α. However, in all CMs, the α was increased when pharmacological compounds were applied indicating of breakdown of fractal complexity. These findings suggest that the intrinsic mechanisms contributing to the fractal complexity are not altered in LQT-CMs. The modulation of IKs channel and β1-adrenoreceptors by pharmacological compounds may affect the fractal complexity of the hiPSC-CMs.
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Neonatal rat cardiomyocytes as an in vitro model for circadian rhythms in the heart. J Mol Cell Cardiol 2017; 112:58-63. [DOI: 10.1016/j.yjmcc.2017.08.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 08/13/2017] [Accepted: 08/16/2017] [Indexed: 02/03/2023]
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Yaniv Y, Ahmet I, Tsutsui K, Behar J, Moen JM, Okamoto Y, Guiriba T, Liu J, Bychkov R, Lakatta EG. Deterioration of autonomic neuronal receptor signaling and mechanisms intrinsic to heart pacemaker cells contribute to age-associated alterations in heart rate variability in vivo. Aging Cell 2016; 15:716-24. [PMID: 27168363 PMCID: PMC4933656 DOI: 10.1111/acel.12483] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/18/2016] [Indexed: 12/19/2022] Open
Abstract
We aimed to determine how age‐associated changes in mechanisms extrinsic and intrinsic to pacemaker cells relate to basal beating interval variability (BIV) reduction in vivo. Beating intervals (BIs) were measured in aged (23–25 months) and adult (3–4 months) C57BL/6 male mice (i) via ECG in vivo during light anesthesia in the basal state, or in the presence of 0.5 mg mL−1 atropine + 1 mg mL−1 propranolol (in vivo intrinsic conditions), and (ii) via a surface electrogram, in intact isolated pacemaker tissue. BIV was quantified in both time and frequency domains using linear and nonlinear indices. Although the average basal BI did not significantly change with age under intrinsic conditions in vivo and in the intact isolated pacemaker tissue, the average BI was prolonged in advanced age. In vivo basal BIV indices were found to be reduced with age, but this reduction diminished in the intrinsic state. However, in pacemaker tissue BIV indices increased in advanced age vs. adults. In the isolated pacemaker tissue, the sensitivity of the average BI and BIV in response to autonomic receptor stimulation or activation of mechanisms intrinsic to pacemaker cells by broad‐spectrum phosphodiesterase inhibition declined in advanced age. Thus, changes in mechanisms intrinsic to pacemaker cells increase the average BIs and BIV in the mice of advanced age. Autonomic neural input to pacemaker tissue compensates for failure of molecular intrinsic mechanisms to preserve average BI. But this compensation reduces the BIV due to both the imbalance of autonomic neural input to the pacemaker cells and altered pacemaker cell responses to neural input.
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Affiliation(s)
- Yael Yaniv
- Biomedical Engineering Faculty Technion‐IIT Haifa Israel
| | - Ismayil Ahmet
- Laboratory of Cardiovascular Science Biomedical Research Center Intramural Research Program National Institute on Aging NIH Baltimore MD USA
| | - Kenta Tsutsui
- Laboratory of Cardiovascular Science Biomedical Research Center Intramural Research Program National Institute on Aging NIH Baltimore MD USA
| | - Joachim Behar
- Biomedical Engineering Faculty Technion‐IIT Haifa Israel
| | - Jack M. Moen
- Laboratory of Cardiovascular Science Biomedical Research Center Intramural Research Program National Institute on Aging NIH Baltimore MD USA
| | - Yosuke Okamoto
- Laboratory of Cardiovascular Science Biomedical Research Center Intramural Research Program National Institute on Aging NIH Baltimore MD USA
| | - Toni‐Rose Guiriba
- Laboratory of Cardiovascular Science Biomedical Research Center Intramural Research Program National Institute on Aging NIH Baltimore MD USA
| | - Jie Liu
- Laboratory of Cardiovascular Science Biomedical Research Center Intramural Research Program National Institute on Aging NIH Baltimore MD USA
| | - Rostislav Bychkov
- Laboratory of Cardiovascular Science Biomedical Research Center Intramural Research Program National Institute on Aging NIH Baltimore MD USA
| | - Edward G. Lakatta
- Laboratory of Cardiovascular Science Biomedical Research Center Intramural Research Program National Institute on Aging NIH Baltimore MD USA
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