Overview

• a form of congenital heart defect
• generally classed as 'acyanotic'. However, uncorrected can eventually result in late cyanosis in the lower extremities, termed differential cyanosis
• connection between the pulmonary trunk and descending aorta
• usually, the ductus arteriosus closes with the first breaths due to increased pulmonary flow which enhances prostaglandins clearance
• more common in premature babies, born at high altitude or maternal rubella infection in the first trimester

Features

• left subclavicular thrill
• continuous 'machinery' murmur
• large volume, bounding, collapsing pulse
• wide pulse pressure
• heaving apex beat

Management

• Treatment of a persistent ductus arteriosus is only required if the baby is symptomatic
• 1/3 of patients with a PDA require treatment with an NSAID
• indomethacin or ibuprofen
  • given to the neonate
  • inhibits prostaglandin synthesis
  • closes the connection in the majority of cases
• if associated with another congenital heart defect amenable to surgery then prostaglandin E1 is useful to keep the duct open until after surgical repair