Frequency of severe pulmonary hypertension complicating "isolated" atrial septal defect in infancy.

Atrial septal defects (ASDs) are typically asymptomatic in infancy and early childhood, and elective defect closure is usually performed at ages of 4 to 6 years. Severe pulmonary hypertension (PH) complicating an ASD is seen in adulthood and has only occasionally been reported in small children. A retrospective study was undertaken to evaluate the incidence of severe PH complicating an isolated ASD and requiring early surgical correction.