title: Heart-rate-corrected QT interval evolution in premature infants during the first week of life.
abstract: Automated monitoring of the QT interval is increasingly common in a variety of clinical settings. A better understanding of how the heart-rate-corrected QT interval (QTc) evolves in early postnatal life is needed before its clinical utility in neonates can be determined. This study aimed to use real-time bedside monitoring as a tool to describe the QTc evolution of premature neonates during the first week of life. All neonates born at a gestation age (GA) of 31 weeks or later and admitted to the level 2 intensive care nursery of the authors' institution between December 2012 and March 2013 were included in this study. The authors prospectively collected QTc values at 15-min intervals during the first week of life, then used two-way analysis of variance (ANOVA) to compare these data among three GA cohorts: 31 to <34 weeks (cohort A), 34 to <37 weeks (cohort B), and ≥37 weeks (cohort C). All the cohorts demonstrated a statistically significant decline in the 24-h average QTc during the first 3-4 days of life before reaching a stable baseline. No diurnal variation in the QTc was identified in any of the study patients. Marked variability and a progressive decline in the QTc of premature neonates occur during the first 3-4 days of life. Understanding this phenomenon is imperative when screening programs for the early detection of QT prolongation are considered.
authors.affiliation: Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: Timothy J B
authors.initials: TJ
authors.lastname: Ulrich
authors.forename: Marc A
authors.initials: MA
authors.lastname: Ellsworth
authors.forename: William A
authors.initials: WA
authors.lastname: Carey
authors.forename: Adeel S
authors.initials: AS
authors.lastname: Zubair
authors.forename: Brianna C
authors.initials: BC
authors.lastname: MacQueen
authors.forename: Christopher E
authors.initials: CE
authors.lastname: Colby
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Ackerman
mesh_terms: D000367:Age Factors; D000704:Analysis of Variance; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D008297:Male; D011446:Prospective Studies