title: QT interval variability in body surface ECG: measurement, physiological basis, and clinical value: position statement and consensus guidance endorsed by the European Heart Rhythm Association jointly with the ESC Working Group on Cardiac Cellular Electrophysiology.
abstract: This consensus guideline discusses the electrocardiographic phenomenon of beat-to-beat QT interval variability (QTV) on surface electrocardiograms. The text covers measurement principles, physiological basis, and clinical value of QTV. Technical considerations include QT interval measurement and the relation between QTV and heart rate variability. Research frontiers of QTV include understanding of QTV physiology, systematic evaluation of the link between QTV and direct measures of neural activity, modelling of the QTV dependence on the variability of other physiological variables, distinction between QTV and general T wave shape variability, and assessing of the QTV utility for guiding therapy. Increased QTV appears to be a risk marker of arrhythmic and cardiovascular death. It remains to be established whether it can guide therapy alone or in combination with other risk factors. QT interval variability has a possible role in non-invasive assessment of tonic sympathetic activity.
authors.affiliation: School of Electrical and Electronic Engineering, The University of Adelaide, Adelaide, SA, Australia.
authors.forename: Mathias
authors.initials: M
authors.lastname: Baumert
authors.affiliation: Department of Biomedical Sciences for Health, University of Milan, Milan, Italy Department of Cardiothoracic, Vascular Anesthesia and Intensive Care, IRCCS Policlinico San Donato, Milan, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Porta
authors.affiliation: Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Marc A
authors.initials: MA
authors.lastname: Vos
authors.affiliation: St Paul's Cardiac Electrophysiology, University of London, and National Heart and Lung Institute, Imperial College, Dovehouse Street, London SW3 6LY, UK marek.malik@btinternet.com.
authors.forename: Marek
authors.initials: M
authors.lastname: Malik
authors.affiliation: Heart Research Follow-Up Program, University of Rochester Medical Center, Rochester, NY, USA.
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Couderc
authors.affiliation: Zaragoza University and CIBER-BBN, Zaragoza, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Laguna
authors.affiliation: Dipartimento di Scienze Cardiovascolari, Respiratorie, Nefrologiche, Anestesiologiche e Geriatriche, Università 'La Sapienza' Rome, Rome, Italy.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Piccirillo
authors.affiliation: Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK.
authors.forename: Godfrey L
authors.initials: GL
authors.lastname: Smith
authors.affiliation: Oregon Health and Science University, Knight Cardiovascular Institute, Portland, OR, USA.
authors.forename: Larisa G
authors.initials: LG
authors.lastname: Tereshchenko
authors.affiliation: Department of Cardiology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Paul G A
authors.initials: PG
authors.lastname: Volders
mesh_terms: D054849:Cardiac Electrophysiology / Q000592:standards*; D032921:Consensus; D004562:Electrocardiography / Q000379:methods*; D005060:Europe; D006801:Humans; D017410:Practice Guidelines as Topic; D012955:Societies, Medical
keywords: Autonomic nervous system; ECG; Heart rate variability; QT interval variability; Repolarization; Sympathetic activity
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