Diastolic flow velocity of the left pulmonary artery of patent ductus arteriosus in preterm infants

BACKGROUND: The usefulness of diastolic pulmonary flow velocity determined by echocardiography in the assessment of symptomatic patent ductus arteriosus (sPDA) in preterm infants has not been confirmed. METHODS: Echocardiography was performed daily in infants ranging from 23 to 31 gestational weeks of age, and diastolic flow velocity of the left pulmonary artery (DFLPA) was measured. The DFLPA data before indomethacin administration for sPDA were compared with data obtained after indomethacin administration. The normal range of DFLPA was also determined from serial measurements performed in infants who did not develop sPDA during the first 7 days of life. Then, this range was compared with data from infants who did develop sPDA during this time. RESULTS: In infants who underwent indomethacin treatment, DFLPA increased with the development of sPDA and decreased when the symptoms of sPDA disappeared. On the basis of results from serial DFLPA measurement, the sensitivity and specificity of DFLPA for assessing sPDA was found to be 0.82 and 0.83, respectively. CONCLUSIONS: Measurement of DFLPA by echocardiography is a useful method for assessing sPDA in preterm infants.