Format

Send to:

Choose Destination
See comment in PubMed Commons below
J Electrocardiol. 2011 Mar-Apr;44(2):96-104. doi: 10.1016/j.jelectrocard.2010.11.010. Epub 2011 Jan 15.

Comparison of 5 methods of QT interval measurements on electrocardiograms from a thorough QT/QTc study: effect on assay sensitivity and categorical outliers.

Author information

  • 1Research Section, Quintiles Cardiac Safety Services, Mumbai, India. vaibhav.salvi@quintiles.com

Abstract

INTRODUCTION:

We studied moxifloxacin-induced QT prolongation and proportion of categorical QTc outliers when 5 methods of QT measurement were used to analyze electrocardiograms (ECGs) from a thorough QT study.

METHODS:

QT interval was measured by the threshold, tangent, superimposed median beat, automated global median beat, and longest QT methods in a central ECG laboratory in 2730 digital ECGs from 39 subjects during placebo and moxifloxacin treatment.

RESULTS:

All 5 methods were able to demonstrate statistically significant moxifloxacin-induced QTcF prolongation. However, lower bound of 95% 1-sided confidence interval of QTcF prolongation did not exceed 5 milliseconds with the longest QT method. More QTcF outliers were observed with the longest QT and tangent methods, whereas the other 3 methods were comparable. QTcF values greater than 500 milliseconds were observed only with moxifloxacin by the tangent method, and with moxifloxacin and placebo by the longest QT method.

CONCLUSION:

The method of QT measurement must be considered when interpreting individual thorough QT/QTc studies.

Copyright © 2011 Elsevier Inc. All rights reserved.

PMID:
21238976
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Write to the Help Desk