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Short-term repeatability of electrocardiographic spatial T-wave axis and QT interval.

TitleShort-term repeatability of electrocardiographic spatial T-wave axis and QT interval.
Publication TypeJournal Article
Year of Publication2005
AuthorsVaidean GD, Schroeder EB, Whitsel EA, Prineas RJ, Chambless LE, Perhac SJ, Heiss G, Rautaharju PM
JournalJ Electrocardiol
Volume38
Issue2
Pagination139-47
Date Published2005 Apr
ISSN0022-0736
KeywordsElectrocardiography, Female, Humans, Long QT Syndrome, Male, Middle Aged, Models, Theoretical, Reproducibility of Results, Signal Processing, Computer-Assisted
Abstract

Although ventricular repolarization abnormalities reflect arrhythmic susceptibility, few reliable tools exist to identify their presence. We investigated the repeatability of the spatial T-wave axis and QT interval from standard 12-lead electrocardiograms in 63 asymptomatic volunteers. Certified technicians used a standardized protocol to digitally record 2 electrocardiograms per participant at each of 2 visits separated by 1 to 2 weeks. Absolute paired differences within and between visits were 0.19 degrees and 0.90 degrees for the T-wave axis and 1.08 and 1.55 milliseconds for the QT interval, respectively. The intraclass correlation coefficients for the T-wave axis and QT interval were 0.87 and 0.86, respectively. The impact of repeated measurements on the precision of the QT-interval measurements was evaluated for a hypothetical clinical trial aimed at detecting a drug-induced QT prolongation. We conclude that the spatial T-wave axis is as repeatable a measure of ventricular repolarization as the QT interval.

DOI10.1016/j.jelectrocard.2004.09.020
Alternate JournalJ Electrocardiol
PubMed ID15892024
Grant List5-T32-HL-07055 / HL / NHLBI NIH HHS / United States
N01-HC-55019 / HC / NHLBI NIH HHS / United States
RR00046 / RR / NCRR NIH HHS / United States