Open AccessThe QT Intervals in Infancy and Time for Infantile ECG Screening for Long QT Syndrome
Author(s) -
Yoshinaga Masao,
Kato Yoshiaki,
Nomura Yuichi,
Hazeki Daisuke,
Yasuda Toshiaki,
Takahashi Kazuhiro,
Higaki Takashi,
Tanaka Yuji,
Wada Akihiro,
Horigome Hitoshi,
Takahashi Hideto,
Ueno Kentaro,
Suzuki Hiroshi,
Nagashima Masami
Publication year - 2011
Publication title -
journal of arrhythmia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.463
H-Index - 21
eISSN - 1883-2148
pISSN - 1880-4276
DOI - 10.1016/s1880-4276(11)80044-x
Subject(s) - medicine , qt interval , long qt syndrome , heart rate , electrocardiography , pediatrics , population , cardiology , sudden infant death syndrome , blood pressure , environmental health
Background: Electrocardiographic and molecular studies have clarified an association between sudden infant death syndrome (SIDS) and long QT syndrome (LQTS), and few data are available for the QT interval in infancy from birth to 1 year of age. Appropriate time of electrocardiographic screening is not clarified. Medical examinations during infancy are mandatory in Japan. Methods and Results: The study population included 1,058 infants. Electrocardiograms were collected with information of infants at birth and at examination. The QT intervals of three consecutive beats were measured in lead V 5 . Statistical analysis revealed that the following formula was appropriate to minimize the effect of heart rate for infants: corrected QT interval; QTc = QT interval/RR interval 0.43 . Subjects were divided into four groups as follows: 0–2, 3–6, 6–11, and 12–52 weeks of age. Tukey's multiple comparison showed that the QTc intervals were longest (p < 0:0001) in subjects who were 6–11 weeks of age. Conclusions: The QTc interval showed the highest peak at 6‐11 weeks of age in infancy. The peak period of occurrence of SIDS is at approximately 2 months of age. An appropriate time of electrocardiographic screening for QT prolongation will be one month of age, and follow‐up studies are needed.