title: The Evaluation of a Borderline Long QT Interval in an Asymptomatic Patient.
abstract: QT prolongation on resting electrocardiography (ECG) is common, and the clinician is often challenged by the dilemma of excluding acquired causes and recognizing potential congenital long QT syndrome (LQTS). The hallmark of LQTS is an abnormally long QT interval. However, a normal or borderline long QT interval may be observed in up to 50% of patients with LQTS because of the intermittent nature of QT prolongation. This review presents an approach to evaluating the asymptomatic patient with a borderline long QT interval, which incorporates a comprehensive clinical assessment, rest and provocative ECG testing, and genetic testing when appropriate.
authors.affiliation: Division of Cardiology, The University of Western Ontario, 339 Windermere Road, London, Ontario N6A 5A5, Canada.
authors.forename: Manoj N
authors.initials: MN
authors.lastname: Obeyesekere
authors.forename: Peter
authors.initials: P
authors.lastname: Leong-Sit
authors.forename: Lorne J
authors.initials: LJ
authors.lastname: Gula
authors.forename: Raymond
authors.initials: R
authors.lastname: Yee
authors.forename: Allan C
authors.initials: AC
authors.lastname: Skanes
authors.forename: George J
authors.initials: GJ
authors.lastname: Klein
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Krahn