Vol 13, No 4 (2006): Folia Cardiologica
Original articles
Published online: 2006-04-24
QTc and dispersion of QT in neonates babies with cardiac arrhythmias
Folia Cardiol 2006;13(4):302-306.
Abstract
Background: The aim of the study was to assess the QTc interval and the dispersion of QT
interval (dQT) in neonates with cardiac arrhythmias.
Material and methods: The study group consisted of 109 neonates with arrhythmias, divided into three groups according to ECG result: group I - 56 babies with premature beats, group II - 35 with bradycardia (heart rate below 80/min) and group III - 18 with tachyarrhythmia (heart rate above 180/min). The control group consisted of 35 healthy neonates.
Results: QTc in the neonates with arrhythmias was calculated from 0.280 s to 0.474 s, with a mean of 0.39 s. In 8 babies it was longer than 0.44 s. The dispersion of QT interval ranged from 10 ms to 80 ms, with a mean of 31 ms. In the control group QTc ranged from 0.324 to 0.432, with a mean of 0.382 s, and dQT from 10 ms to 30 ms, with a mean of 19 ms. The neonates with arrhythmias had significantly longer (p < 0.05) mean values of QTc and dQT compared with the control group. QTc and dQT were also significantly (p < 0.05) longer in the neonates with myocarditis. At the time of discharge from hospital, when the children were aged nearly one month, only 14% had cardiac arrhythmias. After one year follow-up arrhythmias were detected in 8% of them and the mean dispersion of QT was significantly lower (p < 0.05) at this time.
Conclusions: Cardiac arrhythmias in neonates are fairly benign and may disappear during the neonatal period. Greater values of the dispersion of the QT interval in the neonates can be a predisposing factor for arrhythmia. The neonates with myocarditis had greater values of QTc and the dispersion of QT. The neonates with myocarditis had increased values of QTc and QT dispersion.
Material and methods: The study group consisted of 109 neonates with arrhythmias, divided into three groups according to ECG result: group I - 56 babies with premature beats, group II - 35 with bradycardia (heart rate below 80/min) and group III - 18 with tachyarrhythmia (heart rate above 180/min). The control group consisted of 35 healthy neonates.
Results: QTc in the neonates with arrhythmias was calculated from 0.280 s to 0.474 s, with a mean of 0.39 s. In 8 babies it was longer than 0.44 s. The dispersion of QT interval ranged from 10 ms to 80 ms, with a mean of 31 ms. In the control group QTc ranged from 0.324 to 0.432, with a mean of 0.382 s, and dQT from 10 ms to 30 ms, with a mean of 19 ms. The neonates with arrhythmias had significantly longer (p < 0.05) mean values of QTc and dQT compared with the control group. QTc and dQT were also significantly (p < 0.05) longer in the neonates with myocarditis. At the time of discharge from hospital, when the children were aged nearly one month, only 14% had cardiac arrhythmias. After one year follow-up arrhythmias were detected in 8% of them and the mean dispersion of QT was significantly lower (p < 0.05) at this time.
Conclusions: Cardiac arrhythmias in neonates are fairly benign and may disappear during the neonatal period. Greater values of the dispersion of the QT interval in the neonates can be a predisposing factor for arrhythmia. The neonates with myocarditis had greater values of QTc and the dispersion of QT. The neonates with myocarditis had increased values of QTc and QT dispersion.
Keywords: arrhythmianeonatesQTcdQTmyocarditis
