Estimation of the upper limit of the reference value of the QT interval in rest electrocardiograms in healthy young Japanese men using the bootstrap method

Using this limit, we propose a criterion to discriminate cases with prolonged QT intervals. The accuracy of the estimation of the mean and the upper limit of the reference value of the QT was good within the range of the RR interval from 0.812 to 1.263 s (heart rates from 48 to 74 beats per minute). Our approach for estimation of the exponent of RR differs from the well-known exponential equations proposed by Fridericia, but the exponent of RR in our equation is very close to that of Fridericia.