Analysis of Athlete QT Intervals by Age: Fridericia and Hodges Heart Rate Correction Methods Outperform the Bazett's Method for Athlete ECG Screening

Cardiac screening of elite athletes including a 12-lead electrocardiogram (ECG) is recommended by international bodies. Current guidelines recommend use of Bazett’s correction for QT interval. Cricket Australia regularly screens elite players using these criteria. To determine normative QTc changes by age using athlete’s screening ECG and compare performance of various correction methods. 1,297 initial screening ECGs from an existing database of elite Australian cricketers (male n=859; female n=438) aged 14–35 years were examined. QT interval, QTcB (corrected QT–Bazett’s), QTcF (corrected QT–Fridericia), QTcH (corrected QT–Hodges), and heart rate (HR) were analysed by age and sex. A best fit trendline (second order polynomial) was used to calculate the relationship between these parameters and age for males (M) and females (F). Average HR decreased from adolescent to adult ages (R2=0.56(M), R2=0.67(F)). Average absolute QT interval increased over the same time period (R2=0.55 (M), R2=0.64(F)), but less than the HR decrease. This meant that average QTcB decreased from adolescent ages to early adulthood, then increased again (R2=0.16(M); R2=0.20(F)). The expected linear shifts upwards in age were seen with both QTcF (R2=0.22(M); R2=0.13(F)) and QTcH (R2=0.30(M); R2=0.21(F)). Although QT increases slightly with age, in elite cricketers QTcB decreases from adolescence to earlier adulthood, driven by HR decreases. By comparison, QTcF and QTcH increase slowly with age and these alternatives may be a better fit for calculating QTc for athletes with a tendency towards sinus bradycardia.