Snapshot A 7-day-old infant is brought to the pediatrician’s office for poor feeding. She was born to a first time mother without any complications. The mom reports that her infant seems to tire easily when feeding to the point that she is worried about her food intake. On physical exam, the infant has lost more weight than expected. Cardiac exam reveals a grade II/VI continuous machine-like murmur in the left infraclavicular area with a widened pulse pressure. She is sent to receive an echocardiogram for further evaluation. Introduction Clinical definition a persistent opening between the aorta and pulmonary artery that fails to close in the immediate postpartum period Etiology Pathogenesis the ductus arteriosus is normal in utero and typically closes hours after birth patency of PDA is maintained by prostaglandin E2 (PGE2) synthesis and low oxygen tension if unfixed, a large PDA can cause left-to-right shunting in the heart, which increases pulmonary blood flow and causes alterations in the pulmonary vasculature shifting of blood from systemic circulation can cause cyanosis over time, with severe defects, this eventually results in pulmonary hypertension and Eisenmenger syndrome Associated conditions fetal alcohol syndrome congenital rubella neonatal respiratory distress syndrome due to persistently low oxygen tension ventricular septal defect Epidemiology Demographics female > male 2:1 most commonly in premature infants Risk factors maternal rubella infection premature infants in utero alcohol exposure Presentation Symptoms symptoms usually occur with larger defects respiratory distress poor feeding poor weight gain easy fatigability Physical exam cardiac auscultation continuous “machine-like" or "to-and-fro” murmur wide pulse pressure bounding arterial pulses cyanosis and clubbing of lower extremities signs of respiratory distress tachypnea grunting nasal flaring retractions during breathing Imaging Radiography indication for all patients views chest findings enlarged pulmonary artery increased pulmonary markings cardiomegaly Echocardiography indication performed as a diagnostic test most specific test findings ductal flow increased left atrium to aortic root Studies Labs ↑ B-type natriuretic peptide is a biomarker for PDA Electrocardiography indications to assess for arrhythmias findings left ventricular hypertrophy can occur over time Differential Ventricular septal defect distinguishing factor holosystolic murmur Diagnosis Making the diagnosis based on clinical presentation and echocardiogram Treatment Management approach many lesions may close spontaneously premature infants often need medical or surgical treatment Medical indomethacin indications first-line therapy for all patients who do not need the PDA patients with certain congenital cardiac abnormalities that result in the separation of the systemic and pulmonary circulation may require a shunt between the two systems, such as the PDA, to sustain life premature infants with PDA prostaglandin E indication for patients who require PDA to survive e.g., for patients with transposition of the great vessels Operative surgical closure indications failure of PDA to close after medical therapy term infants with large PDAs contraindications severe pulmonary vascular disease (e.g., pulmonary hypertension) Complications Heart failure Eisenmenger syndrome Infective endocarditis Prognosis Typically progresses over time