CLINICAL RESOURCES
Corrected QT Interval
Calculate the corrected QT interval using various formulas
Heart Rate (bpm)
QT Interval (ms)
QRS
Normal
LBBB
RBBB
Formula
Bazett
Fridericia
Framingham
Hodges
Rautaharju
Calculate
Results
QTc:
Reset
References
Bazett HC. An analysis of the time relationships of electrocardiograms. Heart 1920; 7:355.
Fridericia L. Die systolendauer im Elektrokardiogramm bei normalen menschen und bei herzkranken. Acta Med Scand 1920; 53:469.
Sagie A, Larson MG, Goldberg RJ, et al. An improved method for adjusting the QT interval for heart rate (the Framingham Heart Study). Am J Cardiol 1992; 70:797.
Hodges MS, Salerno D, Erlinen D. Bazett's QT correction reviewed: evidence that a linear QT correction for heart rate is better. J Am Coll Cardiol 1983; 1:694.
Rautaharju PM, Mason JW, Akiyama T. New age- and sex-specific criteria for QT prolongation based on rate correction formulas that minimize bias at the upper normal limits. Int J Cardiol. 2014;174(3):535-540.
Alizadeh A, Shahrbaf MA, Khorgami M, et al. QTc interval measurement in patients with right bundle branch block: A practical method. Ann Noninvasive Electrocardiol. 2023;28(2):e13047.
Bogossian H, Frommeyer G, Ninios I, et al. New formula for evaluation of the QT interval in patients with left bundle branch block. Heart Rhythm. 2014;11(12):2273-2277.