Corrected QT Interval (QT)

  • D. John Doyle


The QT interval of the electrocardiogram (ECG) is measured from the onset of ventricular activity to the end of the T wave. Because the QT interval varies with heart rate in normal individuals a “corrected” QT interval is sometimes calculated to factor out heart rate-dependent effects to provide a measure that is independent of rate effects. A normal corrected QT interval should not exceed 440 msec.


Doyle Quinidine 


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  1. 1.
    Wyngaarden JB, et al: Cecil Textbook of Medicine, ed. 17. Philadelphia, WB 1985, Saunders Co, p 173.Google Scholar

Copyright information

© Springer-Verlag New York Inc. 1989

Authors and Affiliations

  • D. John Doyle
    • 1
  1. 1.Institute of Biomedical Engineering and Department of AnaesthesiaUniversity of TorontoTorontoCanada

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