title: Electrocardiographic RR and QT Interval Variability in Patients with Atrial Septal Defect and Healthy Children.
abstract: Atrial septal defect is a common congenital heart disease. In patients with atrial septal defect, left-to-right shunting increases the right atrial and right ventricular preload. This pathological change affects sinus node automaticity and myocardial depolarization and repolarization, and has the potential to evoke arrhythmogenic substrates. We examined the effect of atrial septal defect on sinus node automaticity and myocardial repolarization by investigating the variability in the repolarization interval, namely the QT variability index (QTVI) and variability ratio (VR). This retrospective study included 38 patients (mean age, 2.2 ± 1.9 years; mean left-to-right shunt ratio, 2.1 ± 0.70) and 40 age-matched healthy control subjects evaluated from 2008 to 2015. QTVI was calculated using the ratio of the repolarization parameter variance to heart rate variance, and VR was calculated as the ratio of the standard deviation (SD) of QT intervals to the SD of RR intervals on electrocardiography. There was a significant difference in the SD of all normal RR intervals, heart rate variance, VR, and QTVI of control subjects or patients with low shunt ratio compared with patients with high shunt ratio (all P < 0.05). Linear regression analysis revealed strong positive correlations between the left-to-right shunt ratio and VR (r = 0.662, P < 0.0001) or QTVI (r = 0.808, P < 0.0001). These repolarization indices provide information on alteration of sinus node autonomic control and the pathophysiology of myocardial repolarization, and could be used as a noninvasive indicator of the shunt ratio in children with atrial septal defect.
authors.affiliation: Department of Pediatrics, School of Medicine, Fujita Health University, Toyoake, Japan.
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Eryu
authors.affiliation: Department of Pediatrics, School of Medicine, Fujita Health University, Toyoake, Japan. thata@fujita-hu.ac.jp.|Graduate School of Health Sciences, Fujita Health University, Toyoake, Japan. thata@fujita-hu.ac.jp.
authors.forename: Tadayoshi
authors.initials: T
authors.lastname: Hata
authors.affiliation: Department of Pediatrics, School of Medicine, Fujita Health University, Toyoake, Japan.
authors.forename: Arisa
authors.initials: A
authors.lastname: Nagatani
authors.affiliation: Department of Pediatrics, School of Medicine, Fujita Health University, Toyoake, Japan.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Funamoto
authors.affiliation: Department of Pediatrics, School of Medicine, Fujita Health University, Toyoake, Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Uchida
authors.affiliation: Department of Pediatrics, School of Medicine, Fujita Health University, Toyoake, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Fujino
authors.affiliation: Department of Pediatrics, School of Medicine, Fujita Health University, Toyoake, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Boda
authors.affiliation: Department of Pediatrics, School of Medicine, Fujita Health University, Toyoake, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Miyata
authors.affiliation: Department of Pediatrics, School of Medicine, Fujita Health University, Toyoake, Japan.
authors.forename: Tetsushi
authors.initials: T
authors.lastname: Yoshikawa
mesh_terms: D001145:Arrhythmias, Cardiac / Q000503:physiopathology*; D001341:Autonomic Nervous System / Q000503:physiopathology*; D016022:Case-Control Studies; D002675:Child, Preschool; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006344:Heart Septal Defects, Atrial / Q000503:physiopathology*; D006801:Humans; D007223:Infant; D007564:Japan; D016014:Linear Models; D008297:Male; D012189:Retrospective Studies
keywords: Atrial septal defect; Left-to-right shunting ratio; QT variability index; Repolarization characteristics; Variability ratio