title: Cardiac Function in Newborns with Congenital Hypothyroidism: Association with Thyroid-Stimulating Hormone Levels.
abstract: OBJECTIVE
  The aims of this study were to demonstrate ventricular function changes in patients with congenital hypothyroidism and to investigate whether there is an association between any such changes and thyroid-stimulating hormone (TSH) levels using M-mode and Doppler electrocardiography (ECG) and tissue Doppler imaging (TDI).
  
  
  METHODS
  Twenty-seven patients 5-30 days of age with congenital hypothyroidism who were scheduled to receive L-thyroxine treatment and 20 healthy newborns were included in this study. Twelve-lead ECG and M-mode TDI recordings of the patient and healthy groups were obtained. The patient group was divided into two subgroups according to TSH level (>100 uIU/mL or <100 uIU/mL), which were then compared on all parameters.
  
  
  RESULTS
  Decreases were observed in the ejection fraction (EF), shortening fraction (SF), and mitral lateral annulus, mitral septal annulus, and tricuspid lateral annulus systolic velocity (Sa) on TDI, whereas left ventricular end-systolic diameter (LVESd) and corrected QT interval (QTc) dispersion were significantly increased in the patient group compared with the control group. No significant differences between the groups were found in left ventricular end-diastolic diameter (LVEDd) or heart rate. When the two patient subgroups (TSH >100 uIU/mL and <100 uIU/mL) were compared, TDI septal annulus Sa wave length and heart rate were significantly lower in the TSH >100 group.
  
  
  CONCLUSIONS
  Impairment in left ventricular systolic function and increased risk of arrhythmia were observed in newborn infants with congenital hypothyroidism. TSH level was associated with heart rate and interventricular septum velocity.
authors.forename: Taliha
authors.initials: T
authors.lastname: Öner
authors.affiliation: Dr. Behçet Uz Children's Hospital, Clinic of Pediatric Cardiology, İzmir, Turkey E-mail: rahmiozdemir35@gmail.com.
authors.forename: Rahmi
authors.initials: R
authors.lastname: Özdemir
authors.forename: Önder
authors.initials: Ö
authors.lastname: Doksöz
authors.forename: Yılmaz
authors.initials: Y
authors.lastname: Yozgat
authors.forename: Cem
authors.initials: C
authors.lastname: Karadeniz
authors.forename: Savaş
authors.initials: S
authors.lastname: Demirpençe
authors.forename: Murat Muhtar
authors.initials: MM
authors.lastname: Yılmazer
authors.forename: Muammer
authors.initials: M
authors.lastname: Büyükinan
authors.forename: Timur
authors.initials: T
authors.lastname: Meşe
authors.forename: Vedide
authors.initials: V
authors.lastname: Tavlı
mesh_terms: D003409:Congenital Hypothyroidism / Q000097:blood* / Q000000981:diagnostic imaging*; D006334:Heart Function Tests; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases; D013972:Thyrotropin / Q000097:blood*; D014463:Ultrasonography; D016277:Ventricular Function, Left / Q000502:physiology*
chemical_list: D013972:Thyrotropin