Patency of foramen ovale--does it influence haemodynamics in newborn infants?

Colour-coded Doppler ultrasound examination was carried out in 37 healthy newborns at 24 h of age to determine the patency of the foramen ovale. In addition, Doppler-derived cardiac output was measured 5 times during the first 2 days of life in the same infants. Our aim was to examine the influence of foramen ovale on Doppler-derived cardiac output and its association with left-to-right shunting through the ductus arteriosus. In 22 infants the foramen ovale was patent at 24 h of age and in 15 it was closed. Haemodynamic variables measured using non-imaging Doppler-ultrasonic methods did not differ between these two groups. The closure of left-to-right shunt at the ductus was similar in both groups. In a follow-up examination at the age of 1 year, one child had an open foramen ovale without haemodynamic consequences. This study provides evidence that patency of foramen ovale does not influence hemodynamics in early infancy.