title: Subclinical hypothyroidism and Down's syndrome; studies on myocardial structure and function.
abstract: BACKGROUND
  The management of subclinical hypothyroidism (SH) is still controversial, as the benefit to risk ratio of prolonged L-thyroxine therapy is not clear cut. Some authors have shown abnormalities of myocardial function and structure in adults with SH, which could be reversed by L-thyroxine therapy. As SH frequently affects children with Down's syndrome (DS), and almost one half of these are affected by congenital heart disease, a concomitant SH related impairment of cardiac function might further compromise their clinical condition.
  
  
  OBJECTIVE
  To establish whether SH influences myocardial structure and function in children with DS.
  
  
  METHODS
  Sixteen children with DS and untreated SH and 25 matched euthyroid controls with DS underwent echocardiographic analysis of left ventricular mechanics and tissue characterisation.
  
  
  RESULTS
  None of the 16 patients had myocardial impairment.
  
  
  CONCLUSIONS
  Results suggest that children with DS who have SH are not at risk of cardiac disease. Clinicians should consider these data in the management of SH, as the benefit to risk ratio of prolonged L-thyroxine therapy is not clear cut.
authors: Department of Paediatrics, Federico II University of Naples, Italy.
authors: E
authors: E
authors: Toscano
authors: G
authors: G
authors: Pacileo
authors: G
authors: G
authors: Limongelli
authors: M
authors: M
authors: Verrengia
authors: O
authors: O
authors: Di Mita
authors: S
authors: S
authors: Di Maio
authors: M
authors: M
authors: Salerno
authors: E
authors: E
authors: Del Giudice
authors: B
authors: B
authors: Caniello
authors: R
authors: R
authors: Calabrò
authors: G
authors: G
authors: Andria
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004314:Down Syndrome / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D007223:Infant; D008297:Male; D009206:Myocardium / Q000473:pathology*; D016277:Ventricular Function, Left