alveolar capillary dysplasia should be ruled out in all newborn infants presenting severe idiopathic pulmonary hypertension associated with malformations. Open lung biopsy may prevent from using costly, invasive and probably ineffective procedures such as extracorporeal membrane oxygenation.

Background: Cardiac troponin T (cTnT) has been proposed as specific biochemical marker for myocardial infarction in adults. Cardiac function in neonates could be influenced by the severity of respiratory distress and its ventilatory management. Objectives: To establish a normal range of cTnT in healthy neonates, compare troponin concentrations among healthy neonates and those in respiratory distress (sick) and detect whether any correlation occurs between severity of respiratory distress and troponin concentrations. Methods: Concentrations of cTnT were compared between sick and healthy infants, accountingfor confounding variables in a prospective investigation manner. Age at sampling, need for ventilation, durationof respiratory support, and inotropic use in addition to neonatal and maternal characteristics were assessed. Results: Samples were collected from164 neonates (116 healthy and 48 sick).The medians [interquartile ranges] of cTnT in healthy and sick infants were 0.044 [0.027–0.073]µg/l and 0.121 [0.065–0.238] µg/l, respectively, with p < 0.0001. The 99th percentile for healthy neonates was 0.244 µg/l. Comparing both groups, there were significantdifferences concerning gestation, birth weight, Apgar at 5 min and admission to neonatal intensive care unit. Troponin concentrations in subgroups of sick infants including hypotensive, ventilated and dead infants were higher than other infants of the same subgroup. CTnT was positively correlated to the duration of respiratory support in ventilated neonates. Conclusion: CTnT may prove to be a useful early marker for cardiac and respiratory dysfunction in newborns.