Usefulness of Pasma Atrial Natriuretic Peptide Concentration in the Diagnosis of Patent Ductus Arteriosus in Preterm Infants

PURPOSE: Diagnosis of a hemodynamically significant patent ductus arteriosus(PDA) that should be treated is difficult to determine by clinical and echocardiographic examinations. The aim of this study was to clarify the interrelationship of plasma atrial natriuretic peptide(ANP) concentrations and clinical signs or echocardiographic signs of PDA in preterm infants and use plasma ANP concentrations as a diagnostic indicator of a hemodynamically significant PDA. METHODS: Twenty-four preterm infants who were born at Guro Hospital, Korea Medical Center were evaluated on the 3rd day after birth. Clinical signs(cardiovascular dysfunction score 3) and echocardiographic signs[magnitude of left-to-right shunt across a PDA and left atrium(LA): Ao ratio] of a PDA and plasma ANP concentrations were measured. RESULTS: Plasma ANP concentrations and LA/Ao ratios of preterm infants with hemodynamically significant PDA were significantly higher than those of preterm infants without hemodynamically significant PDA. Plasma ANP concentrations were related to the magnitude of the left- to-right shunt across a PDA and LA: Ao ratio. Plasma ANP concentrations of LA/Ao of more than 1.3 were significantly higher than that of LA/Ao of less than 1.3. CONCLUSION: In preterm infants, high plasma ANP concentration may be a useful predictive indicator of a hemodynarnically significant PDA. Measurement of plasma ANP concentration may play a role in deciding the need for and timing of medical or surgical management of preterm infants with PDA.

Plasma Atrial Natriuretic Peptide and Hemodynamic Change of Patent Ductus Arteriosus in Healthy Low Birth Weight Infants without Clinical Evidence of PDA

PURPOSE: Atrial natriuretic peptide(ANP) is a hormone with strong vasodilating, diu-retic and natriuretic properties. The aim of this study was to clarify the interrelationship of ANP secretion and hemodynamic changes of patent ductus arteriosus(PDA) in healthy preterm and fullterm infants without clinical evidence of PDA. METHODS: Thirteen preterm infants and six full term infants who did not develop clinical evidence of PDA were studied at 6 hr, 12 hr, 24 hr, 3rd day and 4th day after birth, until their PDAs closed spontaneously. Plasma ANP concentrations and the hemodynamic changes of PDA were rneasured. RESULTS: The ANP concentrations of all infants increased from 34.1+/-10.9 pg/ml at 6 hr to 120.5+/-18.8 pg/ml at 12 hr, and declined thereafter gradually to 74.2+/-12.7 pg/ml at 4th day. The ANP concentrations, LA/Ao ratio and LAV decreased after ductal closure. The pulmonary flow velocity(PFV) of PDA correlated with ANP concentration in preterm infants(r=0.23, P<0.05). LA/Ao ratio correlated with ANP contration in all infants (r=0.28, P<0.05), especially in preterm infants(r=0.46, P<0.01 during 12 hr and 4th day after birth. LAV correlated with the ANP concentrations in preterm infants during 12 hr and 4th day after birth(r=0.34, P<0.05). CONCLUSION: The changes of ANP concentrations are probably due to the changes of the left-to-right shunt of PDA with left atrial stretch. Reduction of the ANP concentrations may serve as an indicator of spontaneous closure of PDA. Therefore ANP measurement may be useful in deciding the need and the timing of medical and surgical managernent of newbom infants without clinical evidence of PDA.