Department of Cardiology, Herlev-Gentofte Hospital, Copenhagen University Hospital, Borgmester Ib Juuls Vej 1, DK-2730 Herlev, Copenhagen, Denmark.
Department of Cardiology, The Capital Regions Unit for Inherited Cardiac Diseases, The Heart Center, Rigshospitalet, Copenhagen University Hospital, Inge Lehmanns Vej 7, DK-2100 Copenhagen, Denmark.
Europace. 2021 Feb 5;23(2):278-286. doi: 10.1093/europace/euaa143.
Evaluation of the neonatal QT interval is important to diagnose arrhythmia syndromes and evaluate side effects of drugs. We aimed at describing the natural history of the QT interval duration during the first 4 weeks of life and to provide reference values from a large general population sample.
The Copenhagen Baby Heart Study is a prospective general population study that offered cardiac evaluation of newborns. Eight-lead electrocardiograms were obtained and analysed with a computerized algorithm with manual validation. We included 14 164 newborns (52% boys), aged 0-28 days, with normal echocardiograms. The median values (ms, 2-98%ile) for the corrected intervals QTc (Bazett), QTc (Hodges), QTc (Fridericia), and QTc (Framingham) were 419 (373-474), 419 (373-472), 364 (320-414), and 363 (327-405). During the 4 weeks, we observed a small decrease of QTcFramingham, and an increase of QTcHodges (both P < 0.01), while QTcBazett and QTcFridericia did not change (P > 0.05). Applying published QT interval cut-off values resulted in 5-25% of the newborns having QT prolongation. Uncorrected QT intervals decreased linearly with increasing heart rate (HR). Sex and infant size did not affect the QT interval and the gestational age (GA) only showed an effect when comparing the extreme low- vs. high GA groups (≤34 vs. ≥42 weeks, P = 0.021).
During the 4 weeks QTcFramingham and QTcHodges showed minor changes, whereas QTcBazett and QTcFridericia were stable. The QT interval was unaffected by sex and infant size and GA only showed an effect in very premature newborns. Reference values for HR-specific uncorrected QT intervals may facilitate a more accurate diagnosis of newborns with abnormal QT intervals.
评估新生儿 QT 间期对于诊断心律失常综合征和评估药物的副作用非常重要。我们旨在描述生命最初 4 周内 QT 间期持续时间的自然史，并从大量一般人群样本中提供参考值。
哥本哈根婴儿心脏研究是一项前瞻性的一般人群研究，为新生儿提供心脏评估。获得了 8 导联心电图，并使用计算机算法进行分析，同时进行了手动验证。我们纳入了 14164 名年龄在 0-28 天、超声心动图正常的新生儿。校正后的 QTc（Bazett）、QTc（Hodges）、QTc（Fridericia）和 QTc（Framingham）的中位数（ms，2-98%分位）分别为 419（373-474）、419（373-472）、364（320-414）和 363（327-405）。在 4 周内，我们观察到 QTcFramingham 略有下降，而 QTcHodges 增加（均 P<0.01），而 QTcBazett 和 QTcFridericia 没有变化（P>0.05）。应用已发表的 QT 间期截断值，导致 5-25%的新生儿出现 QT 间期延长。未校正的 QT 间期随心率（HR）的增加呈线性下降。性别和婴儿大小对 QT 间期没有影响，而胎龄（GA）仅在比较极低 GA 组与高 GA 组（≤34 周与≥42 周，P=0.021）时显示出影响。
在 4 周内，QTcFramingham 和 QTcHodges 略有变化，而 QTcBazett 和 QTcFridericia 则保持稳定。QT 间期不受性别和婴儿大小的影响，仅在非常早产儿中 GA 显示出影响。HR 特异性未校正 QT 间期的参考值可能有助于更准确地诊断 QT 间期异常的新生儿。
