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Siland JE, Geelhoed B, Roselli C, Wang B, Lin HJ, Weiss S, Trompet S, van den Berg ME, Soliman EZ, Chen LY, Ford I, Jukema JW, Macfarlane PW, Kornej J, Lin H, Lunetta KL, Kavousi M, Kors JA, Ikram MA, Guo X, Yao J, Dörr M, Felix SB, Völker U, Sotoodehnia N, Arking DE, Stricker BH, Heckbert SR, Lubitz SA, Benjamin EJ, Alonso A, Ellinor PT, van der Harst P, Rienstra M. Resting heart rate and incident atrial fibrillation: A stratified Mendelian randomization in the AFGen consortium. PLoS One 2022; 17:e0268768. [PMID: 35594314 PMCID: PMC9122202 DOI: 10.1371/journal.pone.0268768] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 05/06/2022] [Indexed: 12/02/2022] Open
Abstract
Background Both elevated and low resting heart rates are associated with atrial fibrillation (AF), suggesting a U-shaped relationship. However, evidence for a U-shaped causal association between genetically-determined resting heart rate and incident AF is limited. We investigated potential directional changes of the causal association between genetically-determined resting heart rate and incident AF. Method and results Seven cohorts of the AFGen consortium contributed data to this meta-analysis. All participants were of European ancestry with known AF status, genotype information, and a heart rate measurement from a baseline electrocardiogram (ECG). Three strata of instrumental variable-free resting heart rate were used to assess possible non-linear associations between genetically-determined resting heart rate and the logarithm of the incident AF hazard rate: <65; 65–75; and >75 beats per minute (bpm). Mendelian randomization analyses using a weighted resting heart rate polygenic risk score were performed for each stratum. We studied 38,981 individuals (mean age 59±10 years, 54% women) with a mean resting heart rate of 67±11 bpm. During a mean follow-up of 13±5 years, 4,779 (12%) individuals developed AF. A U-shaped association between the resting heart rate and the incident AF-hazard ratio was observed. Genetically-determined resting heart rate was inversely associated with incident AF for instrumental variable-free resting heart rates below 65 bpm (hazard ratio for genetically-determined resting heart rate, 0.96; 95% confidence interval, 0.94–0.99; p = 0.01). Genetically-determined resting heart rate was not associated with incident AF in the other two strata. Conclusions For resting heart rates below 65 bpm, our results support an inverse causal association between genetically-determined resting heart rate and incident AF.
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Affiliation(s)
- J. E. Siland
- Department of Cardiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - B. Geelhoed
- Department of Cardiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - C. Roselli
- Department of Cardiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Cardiovascular Disease Initiative, The Broad Institute of MIT and Harvard, Cambridge, MA, United States of America
| | - B. Wang
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, United States of America
| | - H. J. Lin
- Institute for Translational Genomics and Population Sciences, The Lundquist Institute at Harbor-UCLA Medical Center, Torrance, CA, United States of America
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States of America
| | - S. Weiss
- Interfaculty Institute for Genetics and Functional Genomics; Department of Functional Genomics; University Medicine Greifswald, Greifswald, Germany
- DZHK (German Centre for Cardiovascular Research); partner site Greifswald, Greifswald, Germany
| | - S. Trompet
- Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands
- Department of Internal Medicine, Section of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, The Netherlands
| | - M. E. van den Berg
- Department of Epidemiology, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - E. Z. Soliman
- Division of Public Health Sciences and Department of Medicine, Epidemiological Cardiology Research Center, Department of Epidemiology and Prevention, Section on Cardiology, Wake Forest School of Medicine, Winston-Salem, NC, United States of America
| | - L. Y. Chen
- Cardiovascular Division, Department of Medicine, University of Minnesota Medical School, Minneapolis, MN, United States of America
| | - I. Ford
- Robertson Centre for Biostatistics, University of Glasgow, Glasgow, United Kingdom
| | - J. W. Jukema
- DZHK (German Centre for Cardiovascular Research); partner site Greifswald, Greifswald, Germany
- Einthoven Laboratory for Experimental Vascular Medicine, LUMC, Leiden, The Netherlands
- Netherlands Heart Institute, Utrecht, The Netherlands
| | - P. W. Macfarlane
- Institute of Health and Wellbeing, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - J. Kornej
- National Heart, Lung, and Blood Institute’s and Boston University’s Framingham Heart Study, Framingham, MA, United States of America
| | - H. Lin
- National Heart Lung and Blood Institute’s and Boston University’s Framingham Heart Study, Framingham, MA, United States of America
- Section of Computational Biomedicine, Department of Medicine, Boston University School of Medicine, Boston, MA, Unites States of America
| | - K. L. Lunetta
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, United States of America
- National Heart, Lung, and Blood Institute’s and Boston University’s Framingham Heart Study, Framingham, MA, United States of America
| | - M. Kavousi
- Department of Epidemiology, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - J. A. Kors
- Department of Medical Informatics, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - M. A. Ikram
- Department of Epidemiology, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - X. Guo
- Institute for Translational Genomics and Population Sciences, The Lundquist Institute at Harbor-UCLA Medical Center, Torrance, CA, United States of America
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States of America
| | - J. Yao
- Institute for Translational Genomics and Population Sciences, Department of Pediatrics, The Lundquist Institute at Harbor-UCLA Medical Center, Torrance, CA, United States of America
| | - M. Dörr
- DZHK (German Centre for Cardiovascular Research); partner site Greifswald, Greifswald, Germany
- Department of Internal Medicine B-Cardiology, Pneumology, Infectious Diseases, Intensive Care Medicine, University Medicine Greifswald, Greifswald, Germany
| | - S. B. Felix
- DZHK (German Centre for Cardiovascular Research); partner site Greifswald, Greifswald, Germany
- Department of Internal Medicine B-Cardiology, Pneumology, Infectious Diseases, Intensive Care Medicine, University Medicine Greifswald, Greifswald, Germany
| | - U. Völker
- Interfaculty Institute for Genetics and Functional Genomics; Department of Functional Genomics; University Medicine Greifswald, Greifswald, Germany
- DZHK (German Centre for Cardiovascular Research); partner site Greifswald, Greifswald, Germany
| | - N. Sotoodehnia
- Cardiovascular Health Research Unit, Division of Cardiology, Departments of Medicine and Epidemiology, University of Washington, Seattle, WA, Unites States of America
| | - D. E. Arking
- McKusick-Nathans Institute, Department of Genetic Medicine, Johns Hopkins University SOM, Baltimore, MD, Unites States of America
| | - B. H. Stricker
- Department of Epidemiology, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - S. R. Heckbert
- Cardiovascular Health Research Unit and the Department of Epidemiology, University of Washington, Seattle, WA, Unites States of America
| | - S. A. Lubitz
- Cardiovascular Disease Initiative, The Broad Institute of MIT and Harvard, Cambridge, MA, United States of America
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA, Unites States of America
- Cardiac Arrhythmia Service, Massachusetts General Hospital, Boston, MA, Unites States of America
| | - E. J. Benjamin
- Institute of Health and Wellbeing, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- Department of Medicine, Boston University School of Medicine, Boston, MA, Unites States of America
- Department of Epidemiology, Boston University School of Public Health, Boston, MA, Unites States of America
| | - A. Alonso
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, Unites States of America
| | - P. T. Ellinor
- Cardiovascular Disease Initiative, The Broad Institute of MIT and Harvard, Cambridge, MA, United States of America
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA, Unites States of America
- Cardiac Arrhythmia Service, Massachusetts General Hospital, Boston, MA, Unites States of America
| | - P. van der Harst
- Department of Cardiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- University of Groningen, University Medical Center Groningen, Department of Genetics, Groningen, The Netherlands
- University Medical Center Utrecht, Department of Heart and Lungs, University of Utrecht, Utrecht, The Netherlands
| | - M. Rienstra
- Department of Cardiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- * E-mail:
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Seyerle AA, Sitlani CM, Noordam R, Gogarten SM, Li J, Li X, Evans DS, Sun F, Laaksonen MA, Isaacs A, Kristiansson K, Highland HM, Stewart JD, Harris TB, Trompet S, Bis JC, Peloso GM, Brody JA, Broer L, Busch EL, Duan Q, Stilp AM, O'Donnell CJ, Macfarlane PW, Floyd JS, Kors JA, Lin HJ, Li-Gao R, Sofer T, Méndez-Giráldez R, Cummings SR, Heckbert SR, Hofman A, Ford I, Li Y, Launer LJ, Porthan K, Newton-Cheh C, Napier MD, Kerr KF, Reiner AP, Rice KM, Roach J, Buckley BM, Soliman EZ, de Mutsert R, Sotoodehnia N, Uitterlinden AG, North KE, Lee CR, Gudnason V, Stürmer T, Rosendaal FR, Taylor KD, Wiggins KL, Wilson JG, Chen YD, Kaplan RC, Wilhelmsen K, Cupples LA, Salomaa V, van Duijn C, Jukema JW, Liu Y, Mook-Kanamori DO, Lange LA, Vasan RS, Smith AV, Stricker BH, Laurie CC, Rotter JI, Whitsel EA, Psaty BM, Avery CL. Pharmacogenomics study of thiazide diuretics and QT interval in multi-ethnic populations: the cohorts for heart and aging research in genomic epidemiology. Pharmacogenomics J 2018; 18:215-226. [PMID: 28719597 PMCID: PMC5773415 DOI: 10.1038/tpj.2017.10] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 01/14/2017] [Accepted: 03/09/2017] [Indexed: 12/23/2022]
Abstract
Thiazide diuretics, commonly used antihypertensives, may cause QT interval (QT) prolongation, a risk factor for highly fatal and difficult to predict ventricular arrhythmias. We examined whether common single-nucleotide polymorphisms (SNPs) modified the association between thiazide use and QT or its component parts (QRS interval, JT interval) by performing ancestry-specific, trans-ethnic and cross-phenotype genome-wide analyses of European (66%), African American (15%) and Hispanic (19%) populations (N=78 199), leveraging longitudinal data, incorporating corrected standard errors to account for underestimation of interaction estimate variances and evaluating evidence for pathway enrichment. Although no loci achieved genome-wide significance (P<5 × 10-8), we found suggestive evidence (P<5 × 10-6) for SNPs modifying the thiazide-QT association at 22 loci, including ion transport loci (for example, NELL1, KCNQ3). The biologic plausibility of our suggestive results and simulations demonstrating modest power to detect interaction effects at genome-wide significant levels indicate that larger studies and innovative statistical methods are warranted in future efforts evaluating thiazide-SNP interactions.
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Affiliation(s)
- A A Seyerle
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA
- Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, MN, USA
| | - C M Sitlani
- Department of Medicine, University of Washington, Seattle, WA, USA
| | - R Noordam
- Department of Epidemiology, Erasmus MC-University Medical Center Rotterdam, Rotterdam, The Netherlands
- Department of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, The Netherlands
| | - S M Gogarten
- Department of Biostatistics, University of Washington, Seattle, WA, USA
| | - J Li
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Palo Alto, CA, USA
| | - X Li
- Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - D S Evans
- California Pacific Medical Center Research Institute, San Francisco, CA, USA
| | - F Sun
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - M A Laaksonen
- Department of Health, THL-National Institute for Health and Welfare, Helsinki, Finland
| | - A Isaacs
- Department of Epidemiology, Erasmus MC-University Medical Center Rotterdam, Rotterdam, The Netherlands
- CARIM School of Cardiovascular Diseases, Maastricht Centre for Systems Biology (MaCSBio), and Department of Biochemistry, Maastricht University, Maastricht, The Netherlands
| | - K Kristiansson
- Department of Health, THL-National Institute for Health and Welfare, Helsinki, Finland
| | - H M Highland
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA
| | - J D Stewart
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA
- Carolina Population Center, University of North Carolina, Chapel Hill, NC, USA
| | - T B Harris
- Laboratory of Epidemiology, Demography, and Biometry, National Institute on Aging, Bethesda, MD, USA
| | - S Trompet
- Department of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, The Netherlands
- Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands
| | - J C Bis
- Department of Medicine, University of Washington, Seattle, WA, USA
| | - G M Peloso
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - J A Brody
- Department of Medicine, University of Washington, Seattle, WA, USA
| | - L Broer
- Department of Internal Medicine, Erasmus MC-University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - E L Busch
- Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Q Duan
- Department of Genetics, University of North Carolina, Chapel Hill, NC, USA
| | - A M Stilp
- Department of Biostatistics, University of Washington, Seattle, WA, USA
| | - C J O'Donnell
- Department of Medicine, Harvard University, Boston, MA, USA
- National Heart, Lung, and Blood Institute Framingham Heart Study, Framingham, MA, USA
- Cardiology Section, Boston Veterans Administration Healthcare, Boston, MA, USA
| | - P W Macfarlane
- Institute of Health and Wellbeing, University of Glasgow, Glasgow, UK
| | - J S Floyd
- Department of Medicine, University of Washington, Seattle, WA, USA
- Department of Epidemiology, University of Washington, Seattle, WA, USA
| | - J A Kors
- Department of Medical Informatics, Erasmus MC-University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - H J Lin
- Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
- Division of Medical Genetics, Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, CA, USA
| | - R Li-Gao
- Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands
| | - T Sofer
- Department of Medicine, University of Washington, Seattle, WA, USA
| | - R Méndez-Giráldez
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA
| | - S R Cummings
- California Pacific Medical Center Research Institute, San Francisco, CA, USA
| | - S R Heckbert
- Department of Epidemiology, University of Washington, Seattle, WA, USA
| | - A Hofman
- Department of Epidemiology, Erasmus MC-University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - I Ford
- Robertson Center for Biostatistics, University of Glasgow, Glasgow, UK
| | - Y Li
- Department of Genetics, University of North Carolina, Chapel Hill, NC, USA
- Department of Biostatistics, University of North Carolina, Chapel Hill, NC, USA
- Department of Computer Science, University of North Carolina, Chapel Hill, NC, USA
| | - L J Launer
- Laboratory of Epidemiology, Demography, and Biometry, National Institute on Aging, Bethesda, MD, USA
| | - K Porthan
- Division of Cardiology, Heart and Lung Center, Helsinki University Central Hospital, Helsinki, Finland
| | - C Newton-Cheh
- Institute of Health and Wellbeing, University of Glasgow, Glasgow, UK
- Center for Human Genetic Research, Massachusetts General Hospital, Boston, MA, USA
- Program in Medical and Population Genetics, Broad Institute, Cambridge, MA, USA
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA, USA
| | - M D Napier
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA
| | - K F Kerr
- Department of Biostatistics, University of Washington, Seattle, WA, USA
| | - A P Reiner
- Department of Epidemiology, University of Washington, Seattle, WA, USA
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - K M Rice
- Department of Biostatistics, University of Washington, Seattle, WA, USA
| | - J Roach
- Research Computing Center, University of North Carolina, Chapel Hill, NC, USA
| | - B M Buckley
- Department of Pharmacology and Therapeutics, University College Cork, Cork, Ireland
| | - E Z Soliman
- Epidemiology Cardiology Research Center (EPICARE), Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - R de Mutsert
- Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands
| | - N Sotoodehnia
- Department of Epidemiology, University of Washington, Seattle, WA, USA
- Division of Cardiology, University of Washington, Seattle, WA, USA
- Cardiovascular Health Research Unit, Department of Medicine, University of Washington, Seattle, WA, USA
| | - A G Uitterlinden
- Department of Internal Medicine, Erasmus MC-University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - K E North
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA
| | - C R Lee
- Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - V Gudnason
- Icelandic Heart Association, Kopavogur, Iceland
- Department of Medicine, University of Iceland, Reykjavik, Iceland
| | - T Stürmer
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA
- Center for Pharmacoepidemiology, University of North Carolina, Chapel Hill, NC, USA
| | - F R Rosendaal
- Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands
| | - K D Taylor
- Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - K L Wiggins
- Department of Medicine, University of Washington, Seattle, WA, USA
| | - J G Wilson
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, USA
| | - Y-Di Chen
- Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - R C Kaplan
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY, USA
| | - K Wilhelmsen
- Department of Genetics, University of North Carolina, Chapel Hill, NC, USA
- The Renaissance Computing Institute, Chapel Hill, NC, USA
| | - L A Cupples
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
- National Heart, Lung, and Blood Institute Framingham Heart Study, Framingham, MA, USA
| | - V Salomaa
- Department of Health, THL-National Institute for Health and Welfare, Helsinki, Finland
| | - C van Duijn
- Department of Epidemiology, Erasmus MC-University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - J W Jukema
- Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands
- Durrer Center for Cardiogenetic Research, Amsterdam, The Netherlands
- Interuniversity Cardiology Institute of the Netherlands, Utrecht, The Netherlands
| | - Y Liu
- Department of Epidemiology and Prevention, Division of Public Health Sciences, Wake Forest University, Winston-Salem, NC, USA
| | - D O Mook-Kanamori
- Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands
- Department of Public Health and Primary Care, Leiden University Medical Center, Leiden, the Netherlands
- Department of BESC, Epidemiology Section, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - L A Lange
- Department of Genetics, University of North Carolina, Chapel Hill, NC, USA
| | - R S Vasan
- National Heart, Lung, and Blood Institute Framingham Heart Study, Framingham, MA, USA
- Division of Preventive Medicine and Epidemiology, Department of Epidemiology, Boston University School of Medicine, Boston, MA, USA
| | - A V Smith
- Icelandic Heart Association, Kopavogur, Iceland
- Department of Medicine, University of Iceland, Reykjavik, Iceland
| | - B H Stricker
- Department of Epidemiology, Erasmus MC-University Medical Center Rotterdam, Rotterdam, The Netherlands
- Inspectorate of Health Care, Utrecht, The Netherlands
| | - C C Laurie
- Department of Biostatistics, University of Washington, Seattle, WA, USA
| | - J I Rotter
- Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - E A Whitsel
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA
- Department of Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - B M Psaty
- Department of Medicine, University of Washington, Seattle, WA, USA
- Department of Epidemiology, University of Washington, Seattle, WA, USA
- Department of Health Services, University of Washington, Seattle, WA, USA
- Group Health Research Institute, Group Health Cooperative, Seattle, WA, USA
| | - C L Avery
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA
- Carolina Population Center, University of North Carolina, Chapel Hill, NC, USA
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Abstract
Abstract:Statistically-based smoothing techniques are described which have been applied to the existing framework of the Glasgow ECG Analysis program. These methods have been designed with the aim of improving repeatability in the computer interpretation of ECGs which have been recorded either several minutes or 24 hours apart from patients in a clinically stable condition. With respect to the ECG diagnosis of Left Ventricular Hypertrophy (LVH), these flexible methods have the effect of reducing the number of inconsistent day-to-day interpretations by 36% from 33 to 21 in330 pairs of ECGs recorded one day apart. Similarly, when comparing agreement in the diagnosis of LVH in 249 pairs of ECGs which were recorded several minutes apart, the number of discordant computer interpretations was 6 using the new methodology, compared with 13 using conventional criteria, i. e. there was a 54% reduction in disagreements.
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Abstract
AbstractThis paper reviews the history of the development of computer methods for ECG interpretation. Selected highlights are presented which indicate how technological advances have paralleled the growth of the application of the technique to a point where globally over 100 million ECGs per annum are now interpreted by computer.
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Arnaud P, van Bemmel JH, Degani R, Macfarlane PW, Zywietz C, Willems JL. Common Standards for Quantitative Electrocardiography: Goals and Main Results. Methods Inf Med 2018. [DOI: 10.1055/s-0038-1634793] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
AbstractComputer processing of electrocardiograms (ECGs) has over the last 15 years increased rapidly. Still, there are at present no standards for computer ECG interpretation. Different techniques are used not only for measurement and interpretation, but also for transmission and storage of data. In order to fill these gaps, a large international project, sponsored by the European Commission, was launched in 1980 to develop “Common Standards for Quantitative Electrocardiography (CSE)”. The main objective of the first CSE study was to reduce the wide variation in wave measurements currently obtained by ECG computer programs. The second study was started in 1985 and aimed at the assessment and improvement of diagnostic classification of ECG interpretation programs. To this end reference libraries of well documented ECGs have been developed and comprehensive reviewing schemes devised for the visual and computer analysis of ECGs. This task was performed by a board of cardiologists in a Delphi review process, and by 9 VCG and 10 standard 12-lead programs developed by university research groups and by industry. A third action was started in June 1989 to harmonize acquisition, encoding, interchange and storing of digital ECG data. The action thus performed have become internationally recognized milestones for the standardization of quantitative electrocardiography.
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Abstract
AbstractThis paper describes the methods currently used in Glasgow Royal Infirmary for computer analysis of electrocardiograms. The software is designed to analyse from 3 to 15 simultaneously recorded leads, with facilities for analysis of rhythm and serial changes. Options for Minnesota Code (with serial comparison) and XYZ lead interpretation are available.
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Dunn FG, Baxter RH, Macfarlane PW, Lawrie TD. The relation of left atrial electrical activity and pressure in myocardial infarction. Adv Cardiol 2015; 16:376-81. [PMID: 1274744 DOI: 10.1159/000398427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Avery CL, Sitlani CM, Arking DE, Arnett DK, Bis JC, Boerwinkle E, Buckley BM, Ida Chen YD, de Craen AJM, Eijgelsheim M, Enquobahrie D, Evans DS, Ford I, Garcia ME, Gudnason V, Harris TB, Heckbert SR, Hochner H, Hofman A, Hsueh WC, Isaacs A, Jukema JW, Knekt P, Kors JA, Krijthe BP, Kristiansson K, Laaksonen M, Liu Y, Li X, Macfarlane PW, Newton-Cheh C, Nieminen MS, Oostra BA, Peloso GM, Porthan K, Rice K, Rivadeneira FF, Rotter JI, Salomaa V, Sattar N, Siscovick DS, Slagboom PE, Smith AV, Sotoodehnia N, Stott DJ, Stricker BH, Stürmer T, Trompet S, Uitterlinden AG, van Duijn C, Westendorp RGJ, Witteman JC, Whitsel EA, Psaty BM. Drug-gene interactions and the search for missing heritability: a cross-sectional pharmacogenomics study of the QT interval. Pharmacogenomics J 2014; 14:6-13. [PMID: 23459443 PMCID: PMC3766418 DOI: 10.1038/tpj.2013.4] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 12/07/2012] [Accepted: 01/03/2013] [Indexed: 01/18/2023]
Abstract
Variability in response to drug use is common and heritable, suggesting that genome-wide pharmacogenomics studies may help explain the 'missing heritability' of complex traits. Here, we describe four independent analyses in 33 781 participants of European ancestry from 10 cohorts that were designed to identify genetic variants modifying the effects of drugs on QT interval duration (QT). Each analysis cross-sectionally examined four therapeutic classes: thiazide diuretics (prevalence of use=13.0%), tri/tetracyclic antidepressants (2.6%), sulfonylurea hypoglycemic agents (2.9%) and QT-prolonging drugs as classified by the University of Arizona Center for Education and Research on Therapeutics (4.4%). Drug-gene interactions were estimated using covariable-adjusted linear regression and results were combined with fixed-effects meta-analysis. Although drug-single-nucleotide polymorphism (SNP) interactions were biologically plausible and variables were well-measured, findings from the four cross-sectional meta-analyses were null (Pinteraction>5.0 × 10(-8)). Simulations suggested that additional efforts, including longitudinal modeling to increase statistical power, are likely needed to identify potentially important pharmacogenomic effects.
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Affiliation(s)
- C L Avery
- Department of Epidemiology, Bank of America Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - C M Sitlani
- Cardiovascular Health Research Unit, University of Washington, Seattle, WA, USA
| | - D E Arking
- McKusick-Nathans Institute of Genetic Medicine and Department of Medicine, Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - D K Arnett
- Department of Epidemiology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - J C Bis
- Cardiovascular Health Research Unit, University of Washington, Seattle, WA, USA
| | - E Boerwinkle
- Division of Epidemiology and Center for Human Genetics, The University of Texas Health Science Center, Houston, TX, USA
| | - B M Buckley
- Department of Pharmacology and Therapeutics, University College Cork, Cork, UK
| | - Y-D Ida Chen
- Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - A J M de Craen
- Department of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, The Netherlands
| | - M Eijgelsheim
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - D Enquobahrie
- Cardiovascular Health Research Unit, University of Washington, Seattle, WA, USA
| | - D S Evans
- California Pacific Medical Center Research Institute, San Francisco, CA, USA
| | - I Ford
- Robertson Centre for Biostatistics, University of Glasgow, Glasgow, UK
| | - M E Garcia
- Laboratory of Epidemiology, Demography, and Biometry, Intramural Research Program, National Institute on Aging, Bethesda, MD, USA
| | - V Gudnason
- Icelandic Heart Association, Kopavogur, Iceland
| | - T B Harris
- Laboratory of Epidemiology, Demography, and Biometry, Intramural Research Program, National Institute on Aging, Bethesda, MD, USA
| | - S R Heckbert
- 1] Cardiovascular Health Research Unit, University of Washington, Seattle, WA, USA [2] Department of Epidemiology, University of Washington, Seattle, WA, USA
| | - H Hochner
- Cardiovascular Health Research Unit, University of Washington, Seattle, WA, USA
| | - A Hofman
- 1] Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands [2] Netherlands Consortium for Healthy Aging (NCHA), Leiden, The Netherlands
| | - W-C Hsueh
- Department of Medicine, University of California, San Francisco, CA, USA
| | - A Isaacs
- 1] Genetic Epidemiology Unit, Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands [2] Centre for Medical Systems Biology, Leiden, The Netherlands
| | - J W Jukema
- Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands
| | - P Knekt
- THL-National Institute for Health and Welfare, Helsinki, Finland
| | - J A Kors
- 1] Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands [2] Department of Medical Informatics, Erasmus Medical Center, Rotterdam, The Netherlands
| | - B P Krijthe
- 1] Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands [2] Netherlands Consortium for Healthy Aging (NCHA), Leiden, The Netherlands
| | - K Kristiansson
- THL-National Institute for Health and Welfare, Helsinki, Finland
| | - M Laaksonen
- THL-National Institute for Health and Welfare, Helsinki, Finland
| | - Y Liu
- Department of Epidemiology and Prevention, Division of Public Health Sciences, Wake Forest University, Winston-Salem, NC, USA
| | - X Li
- Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - P W Macfarlane
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK
| | - C Newton-Cheh
- 1] Program in Medical and Population Genetics, Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA, USA [2] Center for Human Genetic Research, Cardiovascular Research Center, Harvard Medical School, Boston, MA, USA [3] Massachusetts General Hospital, Boston, MA, USA
| | - M S Nieminen
- Division of Cardiology, Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland
| | - B A Oostra
- 1] Genetic Epidemiology Unit, Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands [2] Centre for Medical Systems Biology, Leiden, The Netherlands
| | - G M Peloso
- 1] National Heart Lung and Blood Institute's Framingham Heart Study, Framingham, MA, USA [2] Center for Human Genetic Research, Massachusetts General Hospital, Boston, MA, USA
| | - K Porthan
- Division of Cardiology, Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland
| | - K Rice
- Department of Biostatistics, University of Washington, Seattle, WA, USA
| | - F F Rivadeneira
- 1] Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands [2] Netherlands Consortium for Healthy Aging (NCHA), Leiden, The Netherlands [3] Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - J I Rotter
- Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - V Salomaa
- THL-National Institute for Health and Welfare, Helsinki, Finland
| | - N Sattar
- BHF Glasgow Cardiovascular Research Centre, Faculty of Medicine, Glasgow, UK
| | - D S Siscovick
- 1] Cardiovascular Health Research Unit, University of Washington, Seattle, WA, USA [2] Department of Epidemiology, University of Washington, Seattle, WA, USA
| | - P E Slagboom
- Department of Molecular Epidemiology, Leiden University Medical Center, Leiden, The Netherlands
| | - A V Smith
- Icelandic Heart Association, Kopavogur, Iceland
| | - N Sotoodehnia
- Division of Cardiology, University of Washington, Seattle, WA, USA
| | - D J Stott
- Academic Section of Geriatric Medicine, Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK
| | - B H Stricker
- 1] Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands [2] Netherlands Consortium for Healthy Aging (NCHA), Leiden, The Netherlands [3] Department of Medical Informatics, Erasmus Medical Center, Rotterdam, The Netherlands [4] Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - T Stürmer
- Department of Epidemiology, Bank of America Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - S Trompet
- Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands
| | - A G Uitterlinden
- 1] Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands [2] Netherlands Consortium for Healthy Aging (NCHA), Leiden, The Netherlands [3] Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - C van Duijn
- 1] Genetic Epidemiology Unit, Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands [2] Centre for Medical Systems Biology, Leiden, The Netherlands
| | - R G J Westendorp
- Department of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, The Netherlands
| | - J C Witteman
- 1] Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands [2] Netherlands Consortium for Healthy Aging (NCHA), Leiden, The Netherlands
| | - E A Whitsel
- 1] Department of Epidemiology, Bank of America Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA [2] Departments of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - B M Psaty
- 1] Cardiovascular Health Research Unit, University of Washington, Seattle, WA, USA [2] Department of Epidemiology, University of Washington, Seattle, WA, USA [3] Departments of Medicine, University of Washington, Seattle, WA, USA [4] Department of Health Services, University of Washington, Seattle, WA, USA [5] Group Health Research Institute, Group Health Cooperative, Seattle, WA, USA
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11
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Sattar N, Murray HM, Welsh P, Blauw GJ, Buckley BM, de Craen AJ, Ford I, Forouhi NG, Freeman DJ, Jukema JW, Macfarlane PW, Murphy MB, Packard CJ, Stott DJ, Westendorp RGJ, Shepherd J. Are elevated circulating intercellular adhesion molecule 1 levels more strongly predictive of diabetes than vascular risk? Outcome of a prospective study in the elderly. Diabetologia 2009; 52:235-9. [PMID: 19030842 DOI: 10.1007/s00125-008-1217-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2008] [Accepted: 10/28/2008] [Indexed: 11/29/2022]
Abstract
AIMS/HYPOTHESIS The aim of this prospective study was to determine whether circulating intercellular adhesion molecule (ICAM) 1, as a potential surrogate of 'endothelial activation', is more strongly associated with risk of vascular events than with incident diabetes. METHODS We related baseline ICAM-1 levels to vascular events (866 CHD and stroke events in 5,685 participants) and incident diabetes (292 in 4,945 without baseline diabetes) in the elderly over 3.2 years of follow-up. RESULTS ICAM-1 levels correlated positively with triacylglycerol but negatively with LDL- and HDL-cholesterol. ICAM-1 levels were higher in those who developed diabetes (388.6 +/- 1.42 vs 369.4 +/- 1.39 ng/ml [mean+/-SD], p = 0.011) and remained independently associated with new-onset diabetes (HR 1.84, 95% CI 1.26-2.69, p = 0.0015 per unit increase in log[ICAM-1] after adjusting for classical risk factors and C-reactive protein). By contrast, ICAM-1 levels were not significantly (p = 0.40) elevated in those who had an incident vascular event compared with those who remained event-free, and corresponding adjusted risk associations were null (HR 0.98, 95% CI 0.80-1.22, p = 0.89) in analyses adjusted for other risk factors. CONCLUSIONS/INTERPRETATION We show that elevated ICAM-1 levels are associated with risk of incident diabetes in the elderly at risk, despite no association with incident cardiovascular disease risk. We suggest that perturbations in circulating ICAM-1 levels are aligned more towards diabetes risk.
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Affiliation(s)
- N Sattar
- Faculty of Medicine, BHF Glasgow Cardiovascular Research Centre, University of Glasgow, University Place, Glasgow G12 8TA, UK.
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12
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Trompet S, de Craen AJM, Slagboom P, Shepherd J, Blauw GJ, Murphy MB, Bollen ELEM, Buckley BM, Ford I, Gaw A, Macfarlane PW, Packard CJ, Stott DJ, Westendorp RGJ, Jukema JW. Lymphotoxin-alpha C804A polymorphism is a risk factor for stroke. The PROSPER study. Exp Gerontol 2008; 43:801-5. [PMID: 18504081 DOI: 10.1016/j.exger.2008.04.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2008] [Revised: 04/08/2008] [Accepted: 04/15/2008] [Indexed: 11/30/2022]
Abstract
Inflammation plays a prominent role in the development of atherosclerosis, which is the most important risk factor for vascular events. Lymphotoxin-alpha (LTA) is a pro-inflammatory cytokine and is found to be expressed in atherosclerotic lesions. We investigated the association between the C804A polymorphism within the LTA gene and coronary and cerebrovascular events in 5804 participants of the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER). The primary endpoint was the combined endpoint of death from coronary heart disease, non-fatal myocardial infarction, and clinical stroke. Secondary endpoints were the coronary and cerebrovascular components separately. All associations were assessed with a Cox-proportional hazards model adjusted for sex, age, pravastatin use, and country. Our overall analysis showed a significant association between the C804A polymorphism and the primary endpoint (p = 0.03). After stratification for gender, this association was found only in males. Furthermore, we found that the association between the C804A polymorphism and the primary endpoint was mainly attributable to clinical strokes (p = 0.02). The C804A polymorphism in the LTA gene associates with clinical stroke, especially in men. But further research is warranted to confirm our results.
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Affiliation(s)
- S Trompet
- Department of Cardiology, Leiden University Medical Centre, Leiden, The Netherlands.
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13
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Trompet S, de Craen AJM, Slagboom P, Shepherd J, Blauw GJ, Murphy MB, Bollen ELEM, Buckley BM, Ford I, Gaw A, Macfarlane PW, Packard CJ, Stott DJ, Jukema JW, Westendorp RGJ. Genetic variation in the interleukin-1 beta-converting enzyme associates with cognitive function. The PROSPER study. Brain 2008; 131:1069-77. [PMID: 18304957 DOI: 10.1093/brain/awn023] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Inflammation is thought to play an important role in the development of cognitive decline and dementia in old age. The interleukin-1 signalling pathway may play a prominent role in this process. The gene encoding for interleukin-1 beta-converting enzyme (ICE) is likely to influence IL-1 beta levels. Inhibition of ICE decreases the age-related increase in IL-1 beta levels and may therefore improve memory function. We assessed whether genetic variation in the ICE gene associates with cognitive function in an elderly population. All 5804 participants of the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER) were genotyped for the 10643GC, 9323GA, 8996AG and 5352GA polymorphisms in the ICE gene. Cross-sectional associations between the polymorphisms and cognitive function were assessed with linear regression. Longitudinal associations between polymorphisms, haplotypes and cognitive function were assessed with linear mixed models. All associations were adjusted for sex, age, education, country, treatment with pravastatin and version of test where appropriate. Subjects carrying the variants 10643C and 5352A allele had significantly lower IL-1 beta production levels (P < 0.01). Furthermore, we demonstrated that homozygous carriers of the 10643C and the 5352A allele performed better on all executive function tests at baseline and during follow-up compared to homozygous carriers of the wild-type allele (all P < 0.02). The haplotype with two variants present (10643C and 5352A) was associated with better executive function (all P < 0.02) compared to the reference haplotype without variants. For memory function the same trend was observed, although not significant. Genetic variation in the ICE gene is associated with better performance on cognitive function and lower IL-1 beta production levels. This suggests that low levels of IL-1 beta are protective for memory and learning deficits. Inhibition of ICE may therefore be an important therapeutic target for maintaining cognitive function in old age.
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Affiliation(s)
- S Trompet
- Department of Gerontology and Geriatrics, C-2-R, Leiden University Medical Center, PO Box 9600, 2300 RC, Leiden, The Netherlands.
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14
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Trompet S, Pons D, DE Craen AJM, Slagboom P, Shepherd J, Blauw GJ, Murphy MB, Cobbe SM, Bollen ELEM, Buckley BM, Ford I, Hyland M, Gaw A, Macfarlane PW, Packard CJ, Norrie J, Perry IJ, Stott DJ, Sweeney BJ, Twomey C, Westendorp RGJ, Jukema JW. Genetic Variation in the Interleukin-10 Gene Promoter and Risk of Coronary and Cerebrovascular Events: The PROSPER Study. Ann N Y Acad Sci 2007; 1100:189-98. [PMID: 17460178 DOI: 10.1196/annals.1395.018] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Proinflammatory cytokines, like interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha), are implicated in the development of atherosclerosis. The role of anti-inflammatory cytokines, like IL-10, is largely unknown. We investigated the association of four single nucleotide polymorphisms (SNPs) in the promoter region of the IL-10 gene (4259AG, -1082GA, -592CA, and -2849GA), with coronary and cerebrovascular disease in participants of the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER) trial. All associations were assessed with Cox proportional hazards models adjusted for sex, age, pravastatin use, and country. Haplotype analysis of the four SNPs showed a significant association between haplotype 4 (containing the -592A variant allele) and risk of coronary events (P = 0.019). Moreover, analysis of separate SNPs found a significant association between -2849AA carriers with incident stroke (HR (95%CI) 1.50 (1.04-2.17), P value = 0.02). Our study suggests that not only proinflammatory processes contribute to atherosclerosis, but that also anti-inflammatory cytokines may play an important role.
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Affiliation(s)
- S Trompet
- Department of Gerontology and Geriatrics, C-2-R, Leiden University Medical Center, P.O. Box 9600, 2300 RC, Leiden, The Netherlands.
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15
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Barber M, Morton JJ, Macfarlane PW, Barlow N, Roditi G, Stott DJ. Elevated Troponin Levels Are Associated with Sympathoadrenal Activation in Acute Ischaemic Stroke. Cerebrovasc Dis 2006; 23:260-6. [PMID: 17199083 DOI: 10.1159/000098325] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2006] [Accepted: 08/22/2006] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND It has been hypothesised that elevated serum troponin levels in acute stroke are due to myocardial damage caused by sympathoadrenal activation, which, in turn, may be due particularly to insular damage. We aimed to determine the factors associated with troponin elevation in ischaemic stroke and the prognostic value of this finding. METHODS We studied 222 consecutive acute ischaemic stroke admissions. Serum troponin I and catecholamines were measured. Ischaemic damage on brain computed tomography (CT) scan was graded using the Alberta Stroke Program Early CT Score (ASPECTS). Electrocardiograms were classified using the Minnesota Code and the European Society of Cardiology/American College of Cardiology criteria for acute myocardial infarction. The Rankin scale was recorded at 30 days. RESULTS Forty-five patients (20%) had troponin I >0.2 microg/l. These troponin-positive patients had higher epinephrine levels (median 0.27 vs. 0.17 nmol/l; p = 0.0002) and were more likely to have electrocardiograms coded as definite or possible acute myocardial infarction (odds ratio 3.35; 95% CI 1.26-8.93), compared with those with troponin < or = 0.2 microg/l, in univariate analysis. There were no significant associations between troponin I score and ASPECTS or insular damage on brain CT. In logistic regression analyses, elevated troponin was significantly associated with age, elevated serum creatinine and epinephrine; however, increased troponin was not an independent predictor of death or dependency (Rankin >2) at 30 days. CONCLUSIONS Raised troponin I is associated with elevation of circulating epinephrine in acute ischaemic stroke. Activation of the sympathoadrenal system may be an important contributor to myocardial damage in these patients. Increased troponin is not associated with insular damage and does not independently predict poor outcome.
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Affiliation(s)
- M Barber
- University Division of Cardiovascular and Medical Sciences, Royal Infirmary, Glasgow, UK.
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16
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Macfarlane PW, Norrie J. The value of the electrocardiogram in risk assessment in primary prevention: experience from the West of Scotland Coronary Prevention Study. J Electrocardiol 2006; 40:101-9. [PMID: 17069838 DOI: 10.1016/j.jelectrocard.2006.05.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2005] [Accepted: 05/08/2006] [Indexed: 11/25/2022]
Abstract
Electrocardiograms (ECGs) were recorded at baseline, annually thereafter, and at run-out in the West of Scotland Coronary Prevention Study to which 6595 men aged from 45 to 65 years on entry were recruited. The baseline ECGs were analyzed with respect to (a) the primary end point of the study, namely, fatal or nonfatal myocardial infarction (MI) and (b) all-cause mortality. In addition, incident MIs were reviewed to determine those detected by ECG only. Heart rate, indexed left ventricular mass, frontal T axis, and T amplitude in lead I were all significantly predictive with respect to the primary end point in a multivariate analysis. With respect to all-cause mortality, minor ST-T changes, 10-second heart rate variability, and frontal T axis were similarly predictive. Of 355 incident MIs, 47.3% were silent or unrecognized and detected by ECG only. A simple ECG-based risk prediction equation for fatal and nonfatal MI is introduced.
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Affiliation(s)
- P W Macfarlane
- Division of Cardiovascular and Medical Sciences, University of Glasgow, Scotland, UK.
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17
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Abstract
BACKGROUND Physicians' diagnoses are often used as the gold standard for evaluating computer electrocardiogram (ECG) interpretation programs. As part of a larger study to evaluate the Glasgow pediatric ECG analysis program, inter- and intraobserver variability in the ECG reporting of two pediatric cardiologists was examined. METHODS The ECGs of 984 children were sent for reporting independently by two cardiologists with all identifying information except age and sex removed. Three hundred twenty ECGs had no clinical indication available, and they were thus reported "blind." For 664 ECGs, the clinical indication was known and included with the ECG trace. All ECGs reported as right ventricular hypertrophy (RVH) or left ventricular hypertrophy (LVH) were returned to the cardiologists without their knowledge for reporting a second time "blind" as to the clinical indication. RESULTS When the cardiologists' reports were compared with each other, the provision of clinical information led to greater agreement between them for the diagnosis of LVH (kappa increased from 0.44 to 0.52) but did not substantially affect their agreement in diagnosing RVH (kappa fell from 0.66 to 0.63). Intraindividual comparisons in 166 ECGs revealed that one cardiologist was more consistent in diagnosing RVH and the other more consistent in diagnosing LVH. CONCLUSIONS This study has demonstrated the difficulties in using cardiologists' diagnoses as the gold standard with which to evaluate pediatric ECGs.
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Affiliation(s)
- R. M. Hamilton
- University Department of Medical Cardiology, Glasgow G31 2ER, UK
| | - K. McLeod
- Department of Cardiology, Royal Hospital for Sick Children, Glasgow G3 8SJ, UK
| | - A. B. Houston
- Department of Cardiology, Royal Hospital for Sick Children, Glasgow G3 8SJ, UK
| | - P. W. Macfarlane
- University Department of Medical Cardiology, Glasgow G31 2ER, UK
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18
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Hamilton RM, Houston AB, McLeod K, Macfarlane PW. Evaluation of pediatric electrocardiogram diagnosis of ventricular hypertrophy by computer program compared with cardiologists. Pediatr Cardiol 2005; 26:373-8. [PMID: 15654572 DOI: 10.1007/s00246-004-0748-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
This study aimed to evaluate the diagnosis of pediatric left ventricular hypertrophy (LVH) and right ventricular hypertrophy (RVH) by the Glasgow electrocardiogram (ECG) interpretation program compared to interpretations provided by two pediatric cardiologists. ECGs had all identifying information removed and were sent to the cardiologists independently with the patient's age and sex and the clinical indication for the ECG, if known. A total of 984 ECGs were included in the study, of which 664 were reported "with clinical indication" and 320 were reported "blind." With respect to an averaged diagnosis of the two cardiologists, the sensitivity of the program for RVH was better when the cardiologists reported blind (73.3%) than with the clinical indication (53.5%), with the same trend for the program compared with individual cardiologists. The specificity of the program was at least 94.4% in all cases. For LVH, the program had high specificity (=95.8%) for "reported blind" and "with clinical indication" cases but low sensitivities throughout (the highest was 44.4% with respect to an averaged diagnosis of the two cardiologists reporting with the clinical indication). Subsequent discussion revealed that if the cardiologists had disagreed with one another initially, their consensus opinion was twice as likely to be in agreement with the program.
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Affiliation(s)
- R M Hamilton
- University Section of Cardiology, Division of Cardiovascular and Medical Sciences, Queen Elizabeth Building, Glasgow Royal Infirmary, 10 Alexandra Parade, Glasgow, G31 2ER UK
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19
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van Exel E, de Craen AJM, Remarque EJ, Gussekloo J, Houx P, Bootsma-van der Wiel A, Frölich M, Macfarlane PW, Blauw GJ, Westendorp RGJ. Interaction of atherosclerosis and inflammation in elderly subjects with poor cognitive function. Neurology 2003; 61:1695-701. [PMID: 14694032 DOI: 10.1212/01.wnl.0000098877.07653.7c] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To test the hypothesis that a pro-inflammatory response is associated with cognitive impairment among individuals with cardiovascular disease. METHOD All 85-year-old inhabitants of Leiden (n = 599) were visited at their place of residence. A history of cardiovascular disease and an EKG were used as indicators of atherosclerosis. Production of the pro-inflammatory cytokine tumor necrosis factor-alpha and the anti-inflammatory cytokine interleukin-10 was assessed in a whole-blood assay using lipopolysaccharide as a stimulus. Global cognitive functioning was determined with the Mini-Mental State Examination (MMSE); attention, cognitive speed, and memory were determined with four neuropsychological tests; and a history of dementia was obtained. RESULTS In subjects with cardiovascular disease, median MMSE scores were lower in those with a pro-inflammatory response when compared with those with an anti-inflammatory response (p = 0.02). Similar associations were found for the Stroop Test, measuring attention (p < 0.01), the Coding Test measuring cognitive speed (p = 0.02), the Word Learning Test measuring memory (p < 0.01), and the presence of dementia (p = 0.04). The associations remained unaltered after adjustments for possible confounders such as gender, level of education, use of nonsteroidal anti-inflammatory drugs, use of cardiovascular drugs, and cardiovascular risk factors. In contrast, outcomes of the cognitive tests and presence of dementia were not dependent on the inflammatory response when cardiovascular disease was absent. CONCLUSION The combination of cardiovascular disease and a pro-inflammatory cytokine response may be associated with cognitive impairment and dementia.
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Affiliation(s)
- E van Exel
- Section of Gerontology and Geriatrics, Department of General Internal Medicine, Leiden University Medical Center, the Netherlands
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20
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Corlan AD, Macfarlane PW, De Ambroggi L. Gender differences in stability of the instantaneous patterns of body surface potentials during ventricular repolarisation. Med Biol Eng Comput 2003; 41:536-42. [PMID: 14572003 DOI: 10.1007/bf02345315] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Women have a higher risk of developing torsade de pointes under OT-prolonging conditions. The electrophysiological differences between the sexes that could account for this are largely unknown. The objective of the work was to evaluate gender differences in repolarisation potentials using a method that is independent of the specific electrical properties of the thorax. 1410 normal recordings from the Glasgow 12-lead ECG database and 52 normal ECG maps obtained separately in Milan were analysed. The average difference between 1 and the correlation coefficient of the instantaneous pattern at the peak of T with that at every other instant is called the early repolarisation deviation index (ERDI) for J-T peak and the late repolarisation deviation index (LRDI) for T peak-T end. In standard ECG recordings, the ERDI was 0.42 +/- 0.22 in females compared with 0.19 +/- 0.16 in males (p < 10(-6)). The LRDI was higher in males under the age of 50. In body surface maps, the ERDI was 0.32 +/- 0.21 in females against 0.16 +/- 0.17 in males (p < 0.01), and the LRDI was non-significantly higher in males. The pattern of instantaneous body surface potentials showed gender differences during repolarisation with a method that is independent of the electrical properties of the thorax.
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Affiliation(s)
- A D Corlan
- Cardiology Department, University Hospital of Bucharest, Academy of Medical Sciences, Romania
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21
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de Craen AJM, Gussekloo J, Teng YKO, Macfarlane PW, Westendorp RGJ. Prevalence of five common clinical abnormalities in very elderly people: population based cross sectional study. BMJ 2003; 327:131-2. [PMID: 12869453 PMCID: PMC165698 DOI: 10.1136/bmj.327.7407.131] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/10/2003] [Indexed: 11/03/2022]
Affiliation(s)
- A J M de Craen
- Section of Gerontology and Geriatrics, Department of General Internal Medicine, Leiden University Medical Centre, PO Box 9600, 2300 RC, Leiden, Netherlands.
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Cleland JGF, Pennell DJ, Ray SG, Coats AJ, Macfarlane PW, Murray GD, Mule JD, Vered Z, Lahiri A. Myocardial viability as a determinant of the ejection fraction response to carvedilol in patients with heart failure (CHRISTMAS trial): randomised controlled trial. Lancet 2003; 362:14-21. [PMID: 12853194 DOI: 10.1016/s0140-6736(03)13801-9] [Citation(s) in RCA: 215] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND The improvement in left-ventricular ejection fraction (LVEF) in response to beta blockers is heterogeneous in patients with heart failure due to ischaemic heart disease, possibly indicating variations in the myocardial substrate underlying left-ventricular dysfunction. We investigated whether improvement in LVEF was associated with the volume of hibernating myocardium (viable myocardium with contractile failure). METHODS We did a double-blind, randomised trial to compare placebo and carvedilol for 6 months in individuals with stable, chronic heart failure due to ischaemic left-ventricular systolic dysfunction. We enrolled 489 patients, of whom 387 were randomised. Patients were designated hibernators or non-hibernators according to the volume of hibernating myocardium. The primary endpoint was change in LVEF, measured by radionuclide ventriculography, in hibernators versus non-hibernators, on carvedilol compared with placebo. Analysis was by intention to treat. RESULTS 82 patients dropped out of the study because of adverse events, withdrawal of consent, or failure to complete the investigation. Thus, 305 (79%) were analysed. LVEF was unchanged with placebo (mean change -0.4 [SE 0.9] and -0.4 [0.8] for non-hibernators and hibernators, respectively) but increased with carvedilol (2.5 [0.9] and 3.2 [0.8], respectively; p<0.0001 compared with baseline). Mean placebo-subtracted change in LVEF was 3.2% (95% CI 1.8-4.7; p=0.0001) overall, and 2.9% (0.7-5.1; p=0.011) and 3.6% (1.7-5.4; p=0.0002) in non-hibernators and hibernators, respectively. Effect of hibernator status on response of LVEF to carvedilol was not significant (0.7 [-2.2 to 3.5]; p=0.644). However, patients with more myocardium affected by hibernation or by hibernation and ischaemia had a greater increase in LVEF on carvedilol (p=0.0002 and p=0.009, respectively). INTERPRETATION Some of the effect of carvedilol on LVEF might be mediated by improved function of hibernating or ischaemic myocardium, or both. Medical treatment might be an important adjunct or alternative to revascularisation for patients with hibernating myocardium.
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Macfarlane PW, Colaco R, Stevens K, Reay P, Beckett C, Aitchison T. Precordial electrode placement in women. Neth Heart J 2003; 11:118-122. [PMID: 25696193 PMCID: PMC2499893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023] Open
Abstract
BACKGROUND Precordial ECG electrode positioning was standardised in the early 1940s. However, it has been customary for the V3 to V6 electrodes to be placed under the left breast in women rather than in the correct anatomical positions relating to the 4th and 5th interspaces. For this reason, a comparison between the two approaches to chest electrode positioning in women was undertaken. METHODS In total 84 women were recruited and ECGs recorded with electrodes in the correct anatomical position and also in the more commonly used positions under the breast. As a separate study, 299 healthy women were recruited to study normal limits of leads V3 to V6 recorded with electrodes in the correct anatomical positions and compare them with published normal limits with electrodes in the more commonly used locations. RESULTS It was shown that there was less variability with electrodes in the correct anatomical positions and that there were significant differences between the new limits of normality compared with the old established limits. CONCLUSION Expansion of the database and further analysis of the data is required to make a definitive recommendation with respect to precordial electrode placement in women.
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van Exel E, Gussekloo J, Houx P, de Craen AJM, Macfarlane PW, Bootsma-van der Wiel A, Blauw GJ, Westendorp RGJ. Atherosclerosis and cognitive impairment are linked in the elderly. The Leiden 85-plus Study. Atherosclerosis 2002; 165:353-9. [PMID: 12417287 DOI: 10.1016/s0021-9150(02)00253-8] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Post-mortem analyses suggest that atherosclerosis more often contributes to late-onset dementia than hitherto expected. We set out to further unravel the relation between atherosclerosis and cognitive impairment. We therefore tested the hypothesis that the number of cardiovascular pathologies is positively associated with cognitive impairment in elderly subjects, and that the smaller number of cardiovascular pathologies in women explains the better cognitive function of elderly women. Within the Leiden 85-plus Study, we assessed the atherosclerotic burden by counting the number of cardiovascular pathologies in the medical histories of a population-based sample of 599 subjects aged 85 years (response 87%). Significantly more men than women had a history of cardiovascular pathologies (67% compared to 59%, P<0.001). In addition, cognitive function was assessed. All subjects completed the Mini-Mental State Examination (MMSE). Cognitive speed and memory were determined with specific neuro-psychological tests in those with a MMSE-score above 18 points. There was a highly significant dose-response relationship between the number of cardiovascular pathologies and cognitive impairment for both men and women. The median MMSE-score was 26 points in subjects without cardiovascular disease and decreased to 25 points for subjects who had two or more cardiovascular pathologies (P for trend =0.003). Similar associations were found for cognitive speed but not for memory. Our data confirm that in old age atherosclerosis significantly contributes to cognitive impairment. Since treatments for atherosclerosis appear to be particularly effective in elderly people, we consider our finding of utmost clinical importance in possibly preventing cognitive impairment and late-onset dementia.
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Affiliation(s)
- E van Exel
- Leiden 85-plus Study, Section of Gerontology and Geriatrics, Department of General Internal Medicine, Leiden University Medical Center, C2-R, PO Box 9600, 2300 RC, Leiden, Netherlands
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Abstract
Electrocardiograms (ECGs) from 1,338 apparently healthy adults were analyzed to calculate limits of normality of a variety of ECG measurements. A second set of ECGs from 503 healthy Chinese individuals was also available for comparison of selected normal ranges. It was found that the normal limits of the ST amplitude in healthy individuals decrease with increasing age and, in general terms, are lower in women than in men, particularly in the precordial leads. For example, the upper limit of normal ST amplitude in V3 in a 25-year-old man is 0.31mV but is only 0.11 mV in a woman of the same age. On the other hand, the age-dependent contribution to variation in the upper limit of normal of ST amplitude is effectively confined to men. The one exception to this appears to be the mean ST slope in V2, which decreases with increasing age in both men and women and is higher in the former compared to the latter. Recommended ECG related criteria, particularly in V1, for administration of thrombolytic therapy appear to be neither age nor sex dependent, which is a significant shortcoming given the foregoing information.
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Affiliation(s)
- P W Macfarlane
- University Department of Medical Cardiology, Royal Infirmary, Glasgow, Scotland.
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Jacobsen MD, Wagner GS, Holmvang L, Macfarlane PW, Näslund U, Grande P, Clemmensen P. Clinical significance of abnormal T waves in patients with non-ST-segment elevation acute coronary syndromes. Am J Cardiol 2001; 88:1225-9. [PMID: 11728347 DOI: 10.1016/s0002-9149(01)02081-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
T-wave abnormalities are common electrocardiographic occurrences in patients with non-ST-segment elevation acute coronary syndromes. Although these abnormalities are considered relatively benign, physicians use them to guide therapies. The study objective was to examine the prognostic predictive information of T-wave abnormalities in the setting of unstable coronary artery disease. The T-wave abnormality criterion was based on a new set of normal T-wave amplitude limits differentiated by gender, age, electrocardiographic lead, and QRS axis. Four hundred sixty-eight patients suspected of an acute ischemic incident and considered ineligible for reperfusion therapy were included. Thirteen categories of T-wave abnormalities were tested prospectively. The primary 30-day end point was the combination of refractory angina, myocardial infarction, or death. Quantitative T-wave analysis in an electrocardiographic core laboratory revealed 6 of 13 prespecified categories of T-wave abnormalities that were significantly associated with an adverse outcome. T-wave abnormalities had no prognostic value when ST-segment depression was also present, but this occurred in only 7.9% of patients. T-wave abnormalities as the sole manifestation of ischemia were common (74.4%). Patients with abnormal T waves in > or =1 of 6 selected abnormality categories (70.3%) had a significantly higher risk of death, acute myocardial infarction, and refractory angina (11% vs 3%; p = 0.018). Thus, T-wave abnormalities in patients presenting with non-ST-segment elevation acute coronary syndromes are common and should not automatically be regarded as benign phenomena. Quantitative T- wave analysis provides optimal risk stratification.
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Affiliation(s)
- M D Jacobsen
- The Heart Center, Department of Medicine, Copenhagen University Hospital, Copenhagen, Denmark.
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Mamode N, Docherty G, Lowe GD, Macfarlane PW, Martin W, Pollock JG, Cobbe SM. The role of myocardial perfusion scanning, heart rate variability and D-dimers in predicting the risk of perioperative cardiac complications after peripheral vascular surgery. Eur J Vasc Endovasc Surg 2001; 22:499-508. [PMID: 11735198 DOI: 10.1053/ejvs.2001.1529] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVES To study the value of a number of proposed prognostic factors in prediction of the risk of perioperative cardiac events after vascular surgery. DESIGN AND METHODS Two hundred and ninety-seven patients undergoing peripheral vascular surgery were prospectively studied. Patients underwent preoperative 24 h ambulatory electrocardiography, measurement of haemostatic variables, myocardial assessment of perfusion by dipyridamole-thallium scintigraphy and radionuclide ventriculography. The primary endpoint was cardiac death or nonfatal myocardial infarction within 30 days of surgery. A combined endpoint included the primary endpoint plus occurrence of cardiac failure, unstable angina or serious arrhythmias. RESULTS The primary endpoint occurred in 21 (7%), and the combined endpoint in 41 (14%) of patients. On multivariate analysis, increased age, previous myocardial infarction, aortic surgery, impaired heart rate variability and a positive thallium scan were independent predictors of primary end-points. Preoperative atrial fibrillation and increased fibrin D-dimer were additional predictors of the combined endpoint. Construction of receiver-operator characteristic curves to examine the incremental value of predictive models showed that sensitivity and specificity of clinical data alone for primary endpoints was 71% and 72% respectively, while for the full model (incorporating heart rate variability and thallium data) this rose to 84% and 80% (p=0.0001). CONCLUSIONS Preliminary screening using clinical data has limited value in risk assessment prior to vascular surgery but preoperative heart rate variability, D-dimers and thallium scanning provide modest incremental predictive value.
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Affiliation(s)
- N Mamode
- Department of Vascular Surgery, Medical Cardiology and Medicine, Glasgow, UK
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Abstract
The NeuroScope is a new device which produces a continuous real-time index of cardiac parasympathetic activity (the CIPA) and accurately measures RR intervals. The reproducibility of the CIPA has not yet been assessed. This study was designed to assess the reproducibility of a 5 minute recording of the CIPA using the NeuroScope and compare it with that of conventional heart rate variability (HRV) measures. 50 subjects (31 male, 19 female) aged 21-77 years were recruited. 11 of these were apparently healthy and 39 were patients with a variety of cardiological problems. Two 5 minute recordings of CIPA and RR intervals for each subject were made with a 2-3 minute break between recordings. The limits of agreement for the CIPA were such that the second estimate was between 72 and 140% of the first estimate, 95% of the time. The limits of agreement for other indices of HRV, namely SDNN, rMSSD, In low-frequency HRV and In high-frequency HRV, were 61-157%, 68-153%, 77-131% and 76-133%. The short-term reproducibility of a 5 minute recording of CIPA is moderate and better than simple time-domain but not frequency-domain measures of HRV.
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Affiliation(s)
- P G Murray
- University Department of Medical Cardiology, Glasgow Royal Infirmary, UK
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Freeman DJ, Norrie J, Sattar N, Neely RD, Cobbe SM, Ford I, Isles C, Lorimer AR, Macfarlane PW, McKillop JH, Packard CJ, Shepherd J, Gaw A. Pravastatin and the development of diabetes mellitus: evidence for a protective treatment effect in the West of Scotland Coronary Prevention Study. Circulation 2001; 103:357-62. [PMID: 11157685 DOI: 10.1161/01.cir.103.3.357] [Citation(s) in RCA: 580] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND We examined the development of new diabetes mellitus in men aged 45 to 64 years during the West of Scotland Coronary Prevention Study. METHODS AND RESULTS Our definition of diabetes mellitus was based on the American Diabetic Association threshold of a blood glucose level of >/=7.0 mmol/L. Subjects who self-reported diabetes at baseline or had a baseline glucose level of >/=7.0 mmol/L were excluded from the analyses. A total of 5974 of the 6595 randomized subjects were included in the analysis, and 139 subjects became diabetic during the study. The baseline predictors of the transition from normal glucose control to diabetes were studied. In the univariate model, body mass index, log triglyceride, log white blood cell count, systolic blood pressure, total and HDL cholesterol, glucose, and randomized treatment assignment to pravastatin were significant predictors. In a multivariate model, body mass index, log triglyceride, glucose, and pravastatin therapy were retained as predictors of diabetes in this cohort. CONCLUSIONS We concluded that the assignment to pravastatin therapy resulted in a 30% reduction (P:=0.042) in the hazard of becoming diabetic. By lowering plasma triglyceride levels, pravastatin therapy may favorably influence the development of diabetes, but other explanations, such as the anti-inflammatory properties of this drug in combination with its endothelial effects, cannot be excluded with these analyses.
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Affiliation(s)
- D J Freeman
- Department of Biological Sciences, University of Durham, Durham, UK
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Clark LJ, Watson J, Cobbe SM, Reeve W, Swann IJ, Macfarlane PW. CPR '98: a practical multimedia computer-based guide to cardiopulmonary resuscitation for medical students. Resuscitation 2000; 44:109-17. [PMID: 10767498 DOI: 10.1016/s0300-9572(99)00171-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This paper describes an initiative to build a multimedia computer-based teaching package for cardiopulmonary resuscitation. The project resulted from a perceived gap in the undergraduate medical curriculum allied to concern from medical students. The software application was designed to be networked and used as an adjunct to taught life support courses for undergraduate medical students. The package comprises tutorials and test questions in basic and advanced life support. It incorporates sound, video, graphics and animation to illustrate the techniques involved and is distributed on CD ROM for the PC. The content is based on the 'Advanced Life Support Manual', produced by the Resuscitation Council (UK) and incorporates all changes to the guidelines made during 1997 and 1998. The basic life support section has been networked locally, and has been tested on more than 60 third year medical students attending a local basic life support course. It was found that students who used the package performed significantly better in theoretical assessments than those who did not.
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Affiliation(s)
- L J Clark
- The Microcomputer Cluster, Level 1, Glasgow Royal Infirmary, Glasgow, UK
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32
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Shepherd J, Blauw GJ, Murphy MB, Cobbe SM, Bollen EL, Buckley BM, Ford I, Jukema JW, Hyland M, Gaw A, Lagaay AM, Perry IJ, Macfarlane PW, Meinders AE, Sweeney BJ, Packard CJ, Westendorp RG, Twomey C, Stott DJ. The design of a prospective study of Pravastatin in the Elderly at Risk (PROSPER). PROSPER Study Group. PROspective Study of Pravastatin in the Elderly at Risk. Am J Cardiol 1999; 84:1192-7. [PMID: 10569329 DOI: 10.1016/s0002-9149(99)00533-0] [Citation(s) in RCA: 209] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
The PROspective Study of Pravastatin in the Elderly at Risk (PROSPER) is a randomized, double-blind, placebo-controlled trial designed to test the hypothesis that treatment with pravastatin will diminish risk of subsequent major vascular events in a cohort of men and women (70 to 82 years old) with preexisting vascular disease or significant risk of developing this condition. Five thousand eight hundred four men and women in addition to receiving advice on diet and smoking, have been randomized equally to treatment with 40 mg pravastatin/day or matching placebo in 3 centers (Cork, Ireland, Glasgow, Scotland, and Leiden, The Netherlands). Following an average 3.5-year intervention period, a primary assessment will be made of the influence of this therapy on major vascular events (a combination of coronary heart disease, death, nonfatal myocardial infarction, and fatal and nonfatal stroke). A number of additional analyses will also be conducted on the individual components of the primary end point, on men, on women, and on subjects with and without previous evidence of vascular disease. Finally, an assessment will be made of the effects of treatment on cognitive function, disability, hospitalization or institutionalization, vascular mortality, and all-cause mortality.
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Løchen ML, Rasmussen K, Macfarlane PW, Arnesen E. Can single-lead computerized electrocardiography predict myocardial infarction in young and middle-aged men? The Tromsø study. J Cardiovasc Risk 1999; 6:273-8. [PMID: 10501281 DOI: 10.1177/204748739900600414] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND In epidemiological studies, the electrocardiogram has often been interpreted by means of a categorical classification. Computerized recording offers the possibility of analysing electrocardiographic measurements as continuous variables. OBJECTIVE To test the hypothesis that duration of QRS complex and T-wave inversion would be independent predictors of myocardial infarction. METHODS In a population-based study, we prospectively investigated the risk of developing myocardial infarction according to duration of ORS complex and peak-to-peak T-wave amplitude measured from lead I of the 12-lead electrocardiogram by computerized electrocardiography. In total 6628 men aged 25-61 years who had not previously suffered a myocardial infarction were followed up for 3.9 years. RESULTS Eighty-two first myocardial infarctions (55 non-fatal and 24 fatal myocardial infarctions and three sudden deaths) were identified. The risk of myocardial infarction increased with duration of ORS complex and with decreasing T-wave amplitude. A proportional hazards model with adjustment for possible confounders yielded a relative risk of myocardial infarction of 3.74 (P for linear trend 0.015) for duration of QRS complex > or = 120 ms compared with duration of QRS complex <80 ms. The multivariate relative risk for T-wave amplitude > or = 0.35 mV compared with T-wave amplitude < 0.20 mV was 0.55 (P for linear trend 0.036). When both duration of ORS complex and T-wave amplitude were included in the multivariate model, T-wave amplitude retained its predictive power, whereas duration of ORS complex became marginally no longer significant (P=0.067). CONCLUSIONS Peak-to-peak T-wave amplitude from lead I is an independent predictor of myocardial infarction in men who have not previously suffered a myocardial infarction. Greater duration of ORS complex clearly indicates a higher risk of myocardial infarction. However, when T-wave amplitude is included as a covariate, the predictive power of duration of QRS complex does not remain significant. Single-lead electrocardiography is a feasible method for improving the assessment of the relative risk of myocardial infarction.
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Affiliation(s)
- M L Løchen
- Institute of Community Medicine, University of Tromsø, Norway.
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Affiliation(s)
- P W Macfarlane
- University Department of Medical Cardiology, Royal Infirmary, Glasgow, UK
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van Bemmel JH, van Ginneken AM, Stam H, Assanelli D, Macfarlane PW, Maglaveras N, Rubel P, Zeelenberg C, Zywietz C. Integration and communication for the continuity of cardiac care (I4C). J Electrocardiol 1999; 31 Suppl:60-8. [PMID: 9988007 DOI: 10.1016/s0022-0736(98)90290-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The project I4C (Integration and Communication for the Continuity of Cardiac Care) is carried out for the advancement of cardiac care, from prevention to follow-up. The goals of I4C are: (1) integrated access to patient data, wherever they are stored; (2) support of evidence-based care; (3) consistent recording of patient data (eg, patient history, electrocardiograms IECGs] or cine-angios) in a multimedia patient record; and (4) a documented reference data set for research. In several clinics, workstations are being installed to serve the four goals. Integration with other information systems in clinical care is realized by encapsulation. A computer-based patient record (ORCA) has been developed to support the collection, consultation, and sharing of patient data. In I4C, ORCA is intended for use in a research setting as well as routine patient care. The functionality of ORCA covers the collection of patient history data in a highly structured manner, the recording of drug prescriptions, an overview of laboratory test results, and viewers for ECGs and angiographic images. At present, structured data entry and consultation is supported in six European languages.
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Affiliation(s)
- J H van Bemmel
- Dept of Medical Informatics, Erasmus University, Rotterdam, The Netherlands
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Abstract
BACKGROUND The study of QT dispersion (QTd) is of increasing clinical interest, but there are very few data in large healthy populations. Furthermore, there is still discussion on the extent to which QTd reflects dispersion of measurement. This study addresses these problems. METHODS AND RESULTS Twelve-lead ECGs recorded on 1501 apparently healthy adults and 1784 healthy neonates, infants, and children were used to derive normal limits of QTd and QT intervals by use of a fully automated approach. No age gradient or sex differences in QTd were seen and it was found that an upper limit of 50 ms was highly specific. Three-orthogonal-lead ECGs (n=1220) from the Common Standards for Quantitative Electrocardiography database were used to generate derived 12-lead ECGs, which had a significant increase in QTd of 10.1+/-13.1 ms compared with the original orthogonal-lead ECG but a mean difference of only 1.63+/-12.2 ms compared with the original 12-lead ECGs. In a population of 361 patients with old myocardial infarction, there was a statistically significant increase in mean QTd compared with that of the adult normal group (32.7+/-10.0 versus 24.53+/-8.2 ms; P<0. 0001). An estimate of computer measurement error was also obtained by creating 2 sets of 1220 ECGs from the original set of 1220. The mean error (difference in QTd on a paired basis) was found to be 0. 28+/-9.7 ms. CONCLUSIONS These data indicate that QTd is age and sex independent, has a highly specific upper normal limit of 50 ms, is significantly lower in the 3-orthogonal-lead than in the 12-lead ECG, and is longer in patients with a previous myocardial infarction than in normal subjects.
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Macfarlane PW. Evolution of the Glasgow program for computer-assisted reporting of electrocardiograms--1964/1998. Acta Cardiol 1998; 53:117-20. [PMID: 9684035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- P W Macfarlane
- University Dept. of Medical Cardiology, Royal Infirmary, Glasgow, Scotland
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Abstract
AIMS The coefficient of variation is a popular measure for describing the amount of repeat variability present in ECG measurements from recording to recording. However, it can be misleading. The aim of the present study was to assess repeat variation (reclassification) in computer measured ECG criteria, i.e. positive to negative or vice versa, and compare this with the coefficient of variability. METHODS AND RESULTS Two ECGs were obtained from each of 295 patients, one day apart, and separately from a further 364 patients, several minutes apart. All patients were considered to be in a stable condition. Estimates of the coefficients of variation were obtained for a number of ECG parameters used in the diagnosis of left ventricular hypertrophy. Corresponding reclassification rates of relevant ECG criteria were also calculated. Large coefficients of variation were observed in voltage parameters, e.g. R in V5 (20% for day-to-day recordings and 6% for minute-to-minute recordings) while the corresponding reclassification rates were 8% and 0% respectively. The repeat variation in the diagnosis of left ventricular hypertrophy was up to 5% for day-to-day recordings and up to 3% for minute-to-minute recordings based on several different criteria. CONCLUSION A large coefficient of variation in a particular variable does not necessarily correspond to a high reclassification rate. A better measure of the impact of ECG variability for a particular measurement is obtained from its reclassification rate. In turn, this may have a minimal effect on the overall diagnosis of a particular abnormality.
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Affiliation(s)
- S C McLaughlin
- Department of Medical Cardiology, University of Glasgow, Scotland, U.K
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van der Hofstede JW, Quak AB, van Ginneken AM, Macfarlane PW, Watson J, Hendriks PR, Zeelenberg C. Evaluation plan for a cardiological multi-media workstation (I4C project). Stud Health Technol Inform 1996; 43 Pt B:751-5. [PMID: 10179768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
The goal of the I4C project (Integration and Communication for the Continuity of Cardiac Care) is to build a multi-media workstation for cardiac care and to assess its impact in the clinical setting. This paper describes the technical evaluation plan for the prototype.
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Affiliation(s)
- J W van der Hofstede
- Division of Technology in Health Care, TNO Prevention and Health, Leiden, The Netherlands
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41
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Abstract
The techniques that improve the overall repeatability of computer interpretation of electrocardiograms (ECGs) that have been recorded several minutes apart from patients in a clinically stable condition are described. Estimates of the normal amounts of variability present in many ECG parameters that are used in the identification of a variety of cardiac abnormalities have been adopted in conjunction with smoothing techniques to form the basis of the new methodology. When applied to the Glasgow ECG analysis program, these new methods improve overall repeatability by about 31% when tested on a set of 263 pairs of ECGs. Randomly generated noise was added to the test set and an additional technique aimed at removing noise from the ECG tracings was used in conjunction with the smoothing methods. The observed improvement over the original repeatability was 63%.
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Affiliation(s)
- S C McLaughlin
- University Department of Medical Cardiology, Royal Infirmary, Glasgow, Scotland
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42
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Abstract
The Megacare Electrocardiographic (ECG) Management System (Siemens-Elema, Stockholm, Sweden) incorporates methods for serial comparison of the 12-lead ECG based on the Glasgow interpretation program. While a computer is obviously useful for reporting serial changes following myocardial infarction, it was believed helpful to produce a summary serial comparison statement that would take into account the fact that ECG appearances may normally fluctuate from day to day for a variety of reasons. Thus, five additional summary statements were added to the Glasgow program to indicate the extent of change globally compared to the previous ECG recording. In an ECG management system, an important facility that can potentially cause difficulties with serial comparison is overreading. When a statement has been altered by a reviewer, the changes are required to be incorporated into the ECG file so that in any subsequent serial comparison, the modified report is available for comparison with the next ECG. The Megacare system allows for this, and its methodology is described in this article.
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Abstract
The Minnesota code was introduced in 1960, and since then, a number of computer programs have been written for classifying electrocardiograms according to the rules of the code. However, in 1982, extended rules for serial comparison based on the Minnesota code were published. This article presents the details of implementation of automated serial electrocardiographic comparison using the code. Its application in the West of Scotland Coronary Prevention Study, which was a double-blind trial of lipid lowering in 6.595 men, is also discussed.
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Affiliation(s)
- P W Macfarlane
- University of Glasgow Department of Medical Cardiology, Royal Infirmary, Scotland
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Whincup PH, Wannamethee G, Macfarlane PW, Walker M, Shaper AG. Resting electrocardiogram and risk of coronary heart disease in middle-aged British men. J Cardiovasc Risk 1995; 2:533-43. [PMID: 8665372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE To examine the relation between resting electrocardiographic (ECG) abnormalities and risk of coronary heart disease (CHD). DESIGN AND SETTING This was a prospective study of 7735 middle-aged men aged 40-59 years at entry (British Regional Heart Study). At baseline assessment each man completed a modified World Health Organization (WHO) (Rose) chest-pain questionnaire, gave details of his medical history and had a three-lead orthogonal electrocardiogram recorded. "Symptomatic CHD' refers to a history of anginal chest pain and/or a prolonged episode of central chest pain on WHO questionnaire and/or recall of a doctor diagnosis of CHD (angina or myocardial infarction). MAIN OUTCOME MEASURES These were the first major CHD events, i.e. fatal CHD and non-fatal myocardial infarction, occurring during 9.5 years of follow-up. RESULTS Of 611 first major CHD events during follow-up, 243 (40%) were fatal. After adjustment for age, other ECG abnormalities and symptomatic CHD, the ECG abnormalities most strongly associated with risk of a major CHD event were definite myocardial infarction (relative risk 2.5; 95% confidence interval 1.8-7.5) and definite myocardial ischaemia (1.9; 1.1-2.9). Other ECG abnormalities independently associated with a statistically significant increase in risk were left ventricular hypertrophy (2.2; 1.5-3.3), left axis deviation (1.3; 1.1-1.6) and ectopic beats, particularly if these were ventricular (1.6; 1.1-2.4). Three ECG abnormalities associated with a marked increase in CHD case-fatality rate were pre-existing myocardial infarction (67%), major conduction defect (71%) and arrhythmia (67%); the rate in men with none of these abnormalities was 32%. The relative risks associated with each ECG abnormality were similar in men with and without symptomatic CHD. The increase in risk in the presence of symptomatic CHD (2.4-fold) and ECG evidence of definite myocardial infarction (2.5-fold) was similar; the presence of both factors increased risk more than six-fold. The most serious ECG abnormalities-definite myocardial infarction and ischaemia-were useful predictors of future major CHD events only in men with symptomatic CHD. CONCLUSION The prognostic importance of major ECG abnormalities is strongly influenced by the presence of symptomatic CHD. In men with symptomatic CHD the resting electrocardiogram may help to define a group at high risk who may benefit from intervention. However, it has little or no value as a screening tool in middle-aged men without symptomatic CHD.
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Affiliation(s)
- P H Whincup
- Department of Primary Care and Population Sciences, Royal Free Hospital School of Medicine, London, UK
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McLaughlin SC, Aitchison TC, Macfarlane PW. Methods for improving the repeatability of automated ECG analysis. Methods Inf Med 1995; 34:272-82. [PMID: 7666806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Statistically-based smoothing techniques are described which have been applied to the existing framework of the Glasgow ECG Analysis program. These methods have been designed with the aim of improving repeatability in the computer interpretation of ECGs which have been recorded either several minutes or 24 hours apart from patients in a clinically stable condition. With respect to the ECG diagnosis of Left Ventricular Hypertrophy (LVH), these flexible methods have the effect to reducing the number of inconsistent day-to-day interpretations by 36% from 33 to 21 in 330 pairs of ECGs recorded one day apart. Similarly, when comparing agreement in the diagnosis of LVH in 249 pairs of ECGs which were recorded several minutes apart, the number of discordant computer interpretations was 6 using the new methodology, compared with 13 using conventional criteria, i.e. there was a 54% reduction in disagreements.
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Affiliation(s)
- S C McLaughlin
- Dept. of Medical Cardiology, University of Glasgow, Scotland
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Abstract
BACKGROUND Risk factors specific to sudden cardiac death (SCD), ie, death within 1 hour after onset of symptoms, have been poorly identified, although recent findings from the present study incriminate heavy drinking and elevated heart rate. This paper examines the relations between a wide range of established and potential risk factors for ischemic heart disease (IHD) and SCD to identify independent risk factors for SCD and factors that might particularly or specifically relate to SCD. METHODS AND RESULTS We present a prospective study of a cohort that was drawn from general practices in 24 British towns of 7735 middle-aged men who were followed up for 8 years. During 8 years of follow-up, the men experienced 488 major IHD events (nonfatal and fatal), of which 117 (24%) were classified as SCD. Age, preexisting IHD, arrhythmia, systolic blood pressure, blood cholesterol, elevated heart rate (> or = 90 beats per minute), physical activity (all, P < .05), and, to a lesser extent, smoking (P = .06), HDL cholesterol (P < .07), and elevated hematocrit (> or = 46%, P < .09) emerged as independent risk factors for SCD after adjustment for a wide range of factors. Diabetes was not found to be associated with SCD, and forced expiratory volume in 1 second, body mass index, white blood cell count, and antihypertensive drugs were not associated with risk of SCD after adjustment. When examined in relation to non-sudden IHD deaths and nonfatal myocardial infarction, elevated heart rate, heavy drinking, and arrhythmia emerged as factors that appear to be specific or particular to SCD. These three factors and age and blood cholesterol were associated with an increased risk of SCD in men both with and without preexisting IHD. Physical activity, systolic blood pressure, and current smoking were associated with SCD only in men without preexisting IHD. HDL cholesterol and hematocrit were strong predictors of SCD only in men with preexisting IHD. CONCLUSIONS Three risk factors appear to be specific or particular to the risk of SCD, and these and other risk factors operate differently in patients with versus those without preexisting IHD. These findings have implications for the causes and prevention of SCD.
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Affiliation(s)
- G Wannamethee
- University Department of Public Health, Royal Free Hospital School of Medicine, Glasgow, Scotland
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Mandawat MK, Wallbridge DR, Pringle SD, Riyami AA, Latif S, Macfarlane PW, Lorimer AR, Cobbe SM. Heart rate variability in left ventricular hypertrophy. Br Heart J 1995; 73:139-44. [PMID: 7696023 PMCID: PMC483780 DOI: 10.1136/hrt.73.2.139] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND Electrocardiographic left ventricular hypertrophy and strain are associated with increased cardiac morbidity and mortality. Impaired cardiac autonomic function, assessed non-invasively by spontaneous heart rate variability on Holter monitoring, is associated with an increased risk of sudden death after myocardial infarction. AIM To study the effect of left ventricular hypertrophy on heart rate variability. PATIENTS 36 controls and 154 patients with left ventricular hypertrophy (94 with hypertension and 60 with aortic valve disease). SETTING Tertiary referral centre. METHODS Heart rate variability was measured on 24 h Holter recordings by non-spectral methods. Left ventricular mass index and fractional shortening were measured by echocardiography. RESULTS Patients with left ventricular hypertrophy had a higher left ventricular mass index (P < 0.001) and reduced heart rate variability (P < 0.001) compared with those of the controls. A continuous inverse relation was apparent between heart rate variability and left ventricular mass index (r = -0.478, P < 0.001). Heart rate variability was not affected by age, the presence of coronary artery disease in patients with left ventricular hypertrophy, or beta blocker treatment for hypertension. Multivariate analysis showed that left ventricular mass index is the most important determinant of heart rate variability. CONCLUSION Heart rate variability is significantly reduced in patients with left ventricular hypertrophy secondary to hypertension or aortic valve disease. A continuous inverse relation exists between heart rate variability and left ventricular mass index. Impaired cardiac autonomic function in left ventricular hypertrophy may contribute to the mechanism of sudden death.
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Affiliation(s)
- M K Mandawat
- Department of Medical Cardiology, Royal Infirmary, Glasgow
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Abstract
The derived vectorcardiogram (dVCG) can be obtained from three orthogonal leads X, Y, Z, which are synthesized from the conventional 12-lead ECG by one of a number of mathematical techniques. The application of the dVCG in routine cardiological practice has the advantage of not requiring extra recording electrode other than those used for the conventional 12 electrocardiographic leads, and offers the simultaneous availability of additional dVCG diagnostic information. In this study, the dVCGs were obtained using the inverse Dower method from 1555 apparently healthy Caucasian individuals (884 men and 671 women) and were analysed to determine the age and sex dependent normal ranges of vector measurements in a Caucasian population. The vectorcardiographic parameters measured included the directions of inscription of the QRS vector loops, the magnitude of initial 20 and 30 ms QRS vectors and the direction of the initial 20 ms QRS vector. The maximal spatial QRS vector magnitude, as well as the maximal QRS and T vector magnitudes in the frontal, horizontal, and right sagittal planes, were observed to decrease significantly with advancing age in both sexes (P < 0.001) and were significantly larger in men in all age groups (P < 0.001). The observations from the current study illustrate the significant age and sex dependent differences in the normal ranges of dVCG parameters. These are of potential importance for diagnostic applications.
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Affiliation(s)
- T F Yang
- Department of Medical Cardiology, Glasgow Royal Infirmary, UK
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Abstract
Different forms of artificial intelligence have been applied to pattern recognition in medicine. Recently, however, a relatively new technique involving software-based neural networks has become more readily available. Deterministic logic is currently applied to rhythm analysis in computer-assisted ECG interpretation methods developed in the University of Glasgow. The aim of the present study is to compare an artificial neural network with deterministic logic for separating sinus rhythm (SR) with supraventricular extrasystoles (SVEs) and/or ventricular extra-systoles (VEs) from atrial fibrillation (AF) at a particular point in the diagnostic logic of the Glasgow Program. A total of 2363 ECGs with 1495 AF and 868 SR + (SVEs and/or VEs) are used for training and testing a variety of neural networks, and the optimum design is selected. Methods for combining the results of the neural-network classification and the deterministic interpretation are also developed. A further 717 ECGs are used to test the selected network. The results show that the use of an artificial neural network can improve the sensitivity of reporting AF from 88.5% using the deterministic approach to 92%, without sacrificing specificity (92.3%).
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Affiliation(s)
- T F Yang
- Department of Medical Cardiology, Glasgow Royal Infirmary, UK
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