Corrected QT Interval (QTc)
When you enter QT or RR in millimeters, it is assumed that the ECG is recorded at a speed of 25mm/sec.
With QT expressed in seconds, and Heart Rate (HR) in beats per minute:
RR interval (sec) = 60 / HR.
- Bazett HC (1920) An analysis of the time-relations of electrocardiograms. Heart 7:353-370.
- Fridericia LS (1920) Die Systolendauer im Elektrokardiogramm bei normalen Menschen und bei Herzkranken. [The duration of systole in the electrocardiogram of normal subjects and of patients with heart disease.] Acta Medica Scandinavica 53:469–486.
- Hodges M, Salerno D, Erlien D (1983) Bazett's QT correction reviewed. Evidence that a linear QT correction for heart is better. J Am Coll Cardiol 1:694.
- Sagie A, Larson MG, Goldberg RJ, Bengtson JR, Levy D (1992) An improved method for adjusting the QT interval for heart rate (the Framingham Heart Study). Am J Cardiol 70:797–801.
- QT interval on Wikipedia
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