Spontaneous closure of interatrial septal openings in infants: an echocardiographic study.

Four-hundred-and-fifteen neonates were evaluated by echocardiographic means in order to detect interatrial septal openings and were followed for a maximum time of 18 months. In 68.67% of them, interatrial septal openings were present at the first week of life. The defects were larger than 3 mm in 50.18% of these infants. At the end of the 18th month, openings persisted in 3 cases. The statistical analyses showed significant difference about the percent of closing between the groups with initial opening sizes lesser and bigger than 3 mm. Also, there was a positive correlation between the initial size and the spontaneous closure time. Spontaneous closure incidences were not different in boys and girls. In a small group of infants (4.64%), interatrial openings close forming septal aneurysms. In 12.3% of the newborns without an opening, septal aneurysms were detected during the initial evaluation.