Congenital Heart Defects (acyanotic)

Patent Ductus Arteriosus (PDA)


  • Ductus arteriosus normally creates R ➔ L shunt to bypass fetal lungs. At birth: ↓ PG and bradykinin ➔ closure

  • If ductus arteriosus doesn't close ➔ PDA

    • RF: Prematurity, rubella in 1st trimester, etOH, phenytoin, prostaglandin, Down syndrome


  • Gibson Murmur is a machine-like, continuous (systole & diastole) heard in pulmonic area

    • As pulmonary HTN ↑ ➔ ↓ murmur

    • Once pulmonary pressure > aortic pressure (shunt reversal & Eisenmenger syndrome) ➔ no more murmur

      • Cyanosis in lower extremities (differential cyanosis)

      • Wide pulse pressure (systolic-diastolic difference >30-40mmHg)

  • Silent PDA only seen by ECHO

  • Small PDA - ASX with murmur

  • Moderate - large PDA can ➔ pulmonary artery hypertension, CHF


  • ECHO assesses severity

  • Large PDA shows LAD, LAE, LVH

  • Cardiac cath is definitive but probably only need it before repair


  • If premature/known PDA: NSAIDs ⊣ prostaglandin synthesis (PGE2 keeps ductus open)

    • Indomethacin > ibuprofen (↓ side effects)

  • Symptomatic PDA/heart enlargement/pulmonary HTN ➔ percutaneous catheter occlusion

  • Heart and LUNG transplant once Eisenmenger syndrome develops