title: The prevalence and significance of a short QT interval in 18,825 low-risk individuals including athletes.
abstract: OBJECTIVE
  The short QT syndrome is a cardiac channelopathy characterised by accelerated repolarisation which manifests as a short QT interval on the ECG. The definition of a short QT interval is debated, ranging from <390 to ≤320 ms, and its clinical significance in healthy young individuals is unknown. We assessed the prevalence and medium-term significance of an isolated short QT interval in a diverse young British population.
  
  
  METHODS
  Between 2005 and 2013, 18 825 apparently healthy people aged 14-35 years underwent cardiovascular evaluation with history, physical examination and ECG. QT intervals were measured by cardiologists using 4 recommended guidelines (Seattle 2013, Heart Rhythm Society 2013, European Society of Cardiology 2010 and American Heart Association 2009).
  
  
  RESULTS
  The prevalence of a short QT interval was 0.1% (26 patients, ≤320 ms), 0.2% (44 patients, ≤330 ms), 7.9% (1478 patients, <380 ms), 15.8% (2973 patients, <390 ms). Male gender and Afro-Caribbean ethnicity had the strongest association with short QT intervals. Athletes had shorter QT intervals than non-athletes but athletic status did not predict short QT intervals. Individuals with short QT intervals ≤320 ms did not report syncope or a sinister family history, and during a follow-up period of 5.3±1.2 years, there were no deaths in this group.
  
  
  CONCLUSIONS
  The prevalence of a short QT interval depends on the recommended cut-off value. Even at values ≤320 ms, there was an excellent medium-term prognosis among 14 people followed. We conclude that a definition of ≤320 ms is realistic to prevent overdiagnosis and excessive investigations.
authors.affiliation: Division of Cardiovascular Sciences, St. George's University of London, London, UK.
authors.forename: Harshil
authors.initials: H
authors.lastname: Dhutia
authors.affiliation: Division of Cardiovascular Sciences, St. George's University of London, London, UK.
authors.forename: Aneil
authors.initials: A
authors.lastname: Malhotra
authors.affiliation: Ontario Clinical Oncology Group, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Sameer
authors.initials: S
authors.lastname: Parpia
authors.affiliation: Division of Cardiovascular Sciences, St. George's University of London, London, UK.
authors.forename: Vincent
authors.initials: V
authors.lastname: Gabus
authors.affiliation: Division of Cardiovascular Sciences, St. George's University of London, London, UK.
authors.forename: Gherardo
authors.initials: G
authors.lastname: Finocchiaro
authors.affiliation: Division of Cardiovascular Sciences, St. George's University of London, London, UK.
authors.forename: Greg
authors.initials: G
authors.lastname: Mellor
authors.affiliation: Division of Cardiovascular Sciences, St. George's University of London, London, UK.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Merghani
authors.affiliation: Division of Cardiovascular Sciences, St. George's University of London, London, UK.
authors.forename: Lynne
authors.initials: L
authors.lastname: Millar
authors.affiliation: Division of Cardiovascular Sciences, St. George's University of London, London, UK.
authors.forename: Rajay
authors.initials: R
authors.lastname: Narain
authors.affiliation: Division of Cardiovascular Sciences, St. George's University of London, London, UK.
authors.forename: Nabeel
authors.initials: N
authors.lastname: Sheikh
authors.affiliation: Division of Cardiovascular Sciences, St. George's University of London, London, UK.
authors.forename: Elijah R
authors.initials: ER
authors.lastname: Behr
authors.affiliation: Division of Cardiovascular Sciences, St. George's University of London, London, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Papadakis
authors.affiliation: Division of Cardiovascular Sciences, St. George's University of London, London, UK.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Sharma
mesh_terms: D000293:Adolescent; D000328:Adult; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000453:epidemiology*; D053447:Channelopathies / Q000175:diagnosis / Q000453:epidemiology*; D015331:Cohort Studies; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D015995:Prevalence; D012307:Risk Factors; D013177:Sports / Q000502:physiology*; D006113:United Kingdom / Q000453:epidemiology; D055815:Young Adult
keywords: Cardiology