Evaluation of QT interval correction methods in normal pediatric resting ECGs

Different methods for heart rate correction of QT intervals have been proposed, but the classic Bazett method remains widely used in current clinical practice, despite being often criticized for limitations and disadvantages. To investigate the value of commonly employed methods in pediatric patients, we evaluated four QT correction methods (Bazett, Fridericia, Framingham and Hodges formulae) in a set of 2,170 normal pediatric resting ECGs. The dataset (age 0 to 20 years) is typical of a pediatric population for age, gender and heart rate. Scatter plotting of uncorrected QT versus heart rate reveals curvilinearity not typically identified in previously reported adult normal ECG datasets. Among the four algorithms tested, corrected QT (QTc) values calculated from the Bazett formula yielded the most consistent results across different ranges of heart rate and age. Further statistical regression modeling demonstrated that the Bazett method better fits the overall curvilinear trend in QT-heart rate distribution than the other formulae. The Bazett method also has the least residual heart rate dependence after correction. This study provides support for the use of the Bazett QT correction method over others in normal pediatric resting ECGs. The Bazett method may represent a balance point of accuracy, simplicity and generalizability not yet surpassed by other commonly applied alternatives. Our analysis suggests that its use in general pediatric patients is appropriate as a current best option.