title: Biochemical markers of neonatal myocardial dysfunction.
abstract: BACKGROUND
  Cardiac ultrasounds (US) are not always available at the bedside. Cardiac Troponin I (cTnI), CK-MB and NT-proBNP may be an alternative or complementary to influence evaluation and treatment.
  
  
  OBJECTIVE
  To determine reference ranges of biochemical markers cTnI, CK-MB and NT-proBNP in normal neonates.
  
  
  METHODS
  Cord and blood samples were collected from neonates and the above biochemical markers were determined. Ultrasounds were performed blindly.
  
  
  RESULTS
  CK-MB remains constant from cord blood to the first day, declining thereafter to almost half the values (81.5 vs 52.0 U/l); cTnI increases from 0.004 to 0.058 ng/ml by 72 h falling to 0.030 by day 10; NT-proBNP peaks by 24 h (5085.5 pg/ml), subsiding to 3388.5 pg/ml by day 3, falling to 1316.0 pg/ml by day 10.
  
  
  CONCLUSIONS
  CK-MB, mostly of muscle origin and reflecting labor stress or injury, is not to recommend as a measure of myocardial damage in the neonate. The rise in cTnI may be explained by a degree of myocardial involvement, albeit physiological. The initial rise and subsequent fall of NT-proBNP represents the physiological ventricular overload of transient birth adaptation.
authors.affiliation: Faculty of Health Sciences, Fernando Pessoa University, Oporto, Portugal.
authors.forename: Cristina Maria
authors.initials: CM
authors.lastname: Almeida
authors.forename: Manuel R G
authors.initials: MR
authors.lastname: Carrapato
authors.forename: Fernando
authors.initials: F
authors.lastname: Pinto
authors.forename: Mariana
authors.initials: M
authors.lastname: Pinto
authors.forename: Sofia
authors.initials: S
authors.lastname: Ferreira
authors.forename: Denise
authors.initials: D
authors.lastname: Schmitt
authors.forename: Luis
authors.initials: L
authors.lastname: Marinho
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis / Q000097:blood* / Q000378:metabolism; D016022:Case-Control Studies; D052279:Creatine Kinase, MB Form / Q000097:blood; D005260:Female; D005312:Fetal Blood / Q000378:metabolism; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D009203:Myocardial Infarction / Q000097:blood* / Q000151:congenital* / Q000000981:diagnostic imaging; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D020097:Natriuretic Peptide, Brain / Q000097:blood; D010446:Peptide Fragments / Q000097:blood; D011247:Pregnancy; D019210:Troponin I / Q000097:blood; D016216:Ultrasonography, Prenatal; D055815:Young Adult
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; D019210:Troponin I; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D052279:Creatine Kinase, MB Form