Serendipitous Detection of Umbilical Venous Catheter Displacement by Cardiac Troponin I Measurement

The measurement of cardiac troponin I (cTnI) is pivotal in the biochemical diagnosis of myocardial damage in adults and in infants as well (1). cTnI could also be used in other pathologies that may affect the neonatal heart, such as birth asphyxia, primary pulmonary hypertension, sepsis, and multiple organ system failure (2)(3). A newly born term male suffered a mild episode of asphyxia at birth (Apgar scores: 3 and 9 at 1st and 5th min, respectively) and needed a short resuscitation course at our Neonatal Intensive Care Unit. Blood tests 30 min after delivery showed metabolic acidosis, an arterial lactate concentration of 4.9 mmol/L, and a cTnI concentration of 0.18 μg/L (Dimension RxL-HM; Dade Behring) (4). The cTnI was below the 99th percentile (0.73 μg/L; Fig. 1 ) (5). As part of routine care, we positioned an umbilical venous catheter (UVC) and checked the correct position of its tip in the inferior vena cava by chest x-ray. In the next few hours, both clinical and biochemical indices improved, but a marked increase of cTnI (1.03 μg/L) was detected at 80 h despite the infant’s stable clinical conditions and normal electrocardiogram. Echocardiography demonstrated a normal cardiac contractility but, unexpectedly, revealed that the UVC tip had moved through the foramen ovale into the left atrium. The catheter was immediately removed. At 120 h, a marked decrease in the cTnI concentration (0.36 μg/L) was observed, and echocardiographic and electrocardiographic findings were normal. On day 6, the patient was discharged in good clinical condition.