24 Patent ductus arteriosus
Salient features
History
• Bronchitis or dyspnoea on exertion in severe cases
• Take a maternal history of rubella, particularly in the first trimester
• Determine whether the patient was a premature baby or had a low birth weight. Remember the frequency of patent ductus arteriosus (PDA) in infants weighing 501–1500 g is 31% (Pediatrics 1993;91:540–5)
• Determine whether the patient was born in a place located at a high altitude.
Examination
• Collapsing pulse (caused by an aortic diastolic run-off)
• Systolic and/or diastolic thrill in the left second interspace
• Loud, continuous ‘machinery’ murmur, i.e. pansystolic and extending into early diastole—known as Gibson murmur—is heard along the left upper sternal border and outer border of the clavicle. The murmur begins after the first heart sound, peaks with the second sound, and trails off in diastole (Edinb Med 1890;8:1) (Fig. 24.1)
