title: Heterogeneity of ventricular repolarization in newborns with intrauterine growth restriction.
abstract: BACKGROUND
  Intrauterine growth restriction (IUGR) is associated with structural and functional cardiac alterations but the electrophysiological consequences of these disturbances remain unknown.
  
  
  OBJECTIVE
  To explore the distribution of ventricular repolarization and its relation to myocardial mechanics in newborns with IUGR. STUDY DESIGN, SUBJECTS AND OUTCOME MEASUREMENTS: Conventional and tissue Doppler echocardiographic data, and electrocardiographic parameters used to describe the distribution of ventricular repolarization (dispersion of QT [QTd] and JT [JTd]), were obtained on the second (D2) and fifth (D5) postnatal day and compared between 25 IUGR newborns and 25 matched-for-gestational age controls.
  
  
  RESULTS
  IUGR was associated with relative interventricular septum hypertrophy, increased left ventricular (LV) E/E' ratio and higher LV myocardial performance index (MPI). On both study days, the IUGR infants presented higher QTd and JTd compared to controls (QTd-D2: 66±20 ms vs. 36±12 ms, P<0.001; JTd-D2: 54±13 ms vs. 34±9 ms, P<0.001; QTd-D5: 61±14 ms vs. 27±12 ms, P<0.001; JTd-D5: 54±13 ms vs. 27±9 ms, P<0.001). The association between QTd and LV E/E' (D2: regression coefficient beta 0.747, R(2) 0.585; D5: beta 0.843, R(2) 0.646) and QTd and MPI (D2: beta 0.680, R(2) 0.576; D5: beta 0.698, R(2) 0.650) was also significant (P<0.001 for all analyses).
  
  
  CONCLUSIONS
  Our findings suggest that IUGR is associated with electrophysiological remodeling of the neonatal heart, a process which is closely related to the underlying alterations in ventricular mechanics and might predispose to adverse electrophysiological events.
authors.affiliation: Neonatal Intensive Care Unit, University Hospital of Patras and University of Patras Medical School, Patras, Greece; Department of Pediatrics, University Hospital of Patras and University of Patras Medical School, Patras, Greece. Electronic address: sfouzas@gmail.com.
authors.forename: Sotirios
authors.initials: S
authors.lastname: Fouzas
authors.affiliation: Neonatal Intensive Care Unit, University Hospital of Patras and University of Patras Medical School, Patras, Greece; Department of Pediatrics, University Hospital of Patras and University of Patras Medical School, Patras, Greece; Pediatric Cardiology Unit, University Hospital of Patras and University of Patras Medical School, Patras, Greece.
authors.forename: Ageliki A
authors.initials: AA
authors.lastname: Karatza
authors.affiliation: Department of Cardiology, University Hospital of Patras and University of Patras Medical School, Patras, Greece.
authors.forename: Periklis A
authors.initials: PA
authors.lastname: Davlouros
authors.affiliation: Department of Pediatrics, University Hospital of Patras and University of Patras Medical School, Patras, Greece.
authors.forename: Dionisios
authors.initials: D
authors.lastname: Chrysis
authors.affiliation: Department of Cardiology, University Hospital of Patras and University of Patras Medical School, Patras, Greece.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Alexopoulos
authors.affiliation: Neonatal Intensive Care Unit, University Hospital of Patras and University of Patras Medical School, Patras, Greece; Department of Pediatrics, University Hospital of Patras and University of Patras Medical School, Patras, Greece.
authors.forename: Stefanos
authors.initials: S
authors.lastname: Mantagos
authors.affiliation: Neonatal Intensive Care Unit, University Hospital of Patras and University of Patras Medical School, Patras, Greece; Department of Pediatrics, University Hospital of Patras and University of Patras Medical School, Patras, Greece.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Dimitriou
mesh_terms: D016022:Case-Control Studies; D004562:Electrocardiography; D005260:Female; D005317:Fetal Growth Retardation / Q000503:physiopathology*; D005318:Fetal Heart / Q000254:growth & development / Q000473:pathology / Q000503:physiopathology; D006321:Heart / Q000254:growth & development / Q000503:physiopathology*; D006330:Heart Defects, Congenital / Q000150:complications; D006801:Humans; D007231:Infant, Newborn; D008297:Male
keywords: Intrauterine growth restriction; Neonates; QT dispersion; Ventricular repolarization