Benatar Abraham, Feenstra Arjen
Department of Pediatric Cardiology, University Hospital UZ Brussel, Free University of Brussels (VUB), Brussels, Belgium.
Ann Noninvasive Electrocardiol. 2015 Mar;20(2):119-25. doi: 10.1111/anec.12200. Epub 2014 Sep 9.
Accurate determination of the QTc interval in children is important especially when using drugs which can prolong cardiac repolarization. Previous work suggests the most appropriate correction formula to be QTc = QT/RR(0.38) . We set out to compute the best population-derived age and gender-related QT correction formula factor in normal children.
We evaluated a cohort of 1400 healthy children. From a resting 12-lead electrocardiogram, QT and RR intervals were measured. Subjects were divided into four age and gender groups: 0-1 years (n = 540); 1-5 years (n = 281); 5-10 years (n = 277), and > 10 years (n = 302). QT/RR intervals were plotted and fitted with two regression analyses, linear regression obtaining constant α (QTc = QT + α x (1-RR)), and log-linear analysis deriving constant β (QTc = QT/RR(β) ). Furthermore, regression analysis of QTc/RR for the two formulas was performed obtaining slope and R(2) .
Correction constant α decreased steadily with increasing age, genders remained on par until 10 years of age followed by more pronounced decrease in females (range 0.24-0.18). The β constant showed a similar trend however with more pronounced decline (range 0.45-0.31). Regression slopes of QTc/RR plots (all ages and both genders) were close to zero (both formulas).
For the full range of pediatric subjects, the optimum population-based correction factors α and β decreased with increasing age and gender, digressing more so in adolescent girls. More specific correction factors, based on age and gender, are necessary in QT correction.
准确测定儿童的QTc间期非常重要，尤其是在使用可能延长心脏复极的药物时。先前的研究表明，最合适的校正公式为QTc = QT/RR(0.38)。我们着手计算正常儿童中基于人群的最佳年龄和性别相关QT校正公式因子。
我们评估了一组1400名健康儿童。从静息12导联心电图中测量QT和RR间期。受试者分为四个年龄和性别组：0 - 1岁（n = 540）；1 - 5岁（n = 281）；5 - 10岁（n = 277），以及>10岁（n = 302）。绘制QT/RR间期并通过两种回归分析进行拟合，线性回归得到常数α（QTc = QT + α x (1 - RR)），对数线性分析得出常数β（QTc = QT/RR(β)）。此外，对这两个公式的QTc/RR进行回归分析，得到斜率和R(2)。
校正常数α随着年龄的增加而稳步下降，在10岁之前男女相当，之后女性下降更为明显（范围0.24 - 0.18）。β常数呈现类似趋势，但下降更为明显（范围0.45 - 0.31）。QTc/RR图的回归斜率（所有年龄和性别）接近零（两个公式均如此）。
对于所有儿科受试者，基于人群的最佳校正因子α和β随着年龄和性别的增加而下降，在青春期女孩中偏离更为明显。在QT校正中，需要更具体的基于年龄和性别的校正因子。
