Progressive obstruction of the foramen ovale in patients with left atrioventricular valve atresia.

Thirteen patients with left atrioventricular (AV) valve atresia and a normal aortic root were studied to evaluate the status of the interatrial communication with advancing age. Six patients had cardiac catheterization within the first 2 weeks of age; of these, five had repeat studies before 7 months of age. The seven other patients initially underwent catheterization after 2 weeks of age. In the group with catheterization before 2 weeks of age, the mean left atrial pressure was 7.8 +/- 5.5 mm Hg and the left atrial-right atrial mean pressure gradient was 1.7 +/- 2.4 mm Hg. In the combined group of patients with catheterization after 2 weeks of age, the mean left atrial pressure was 25.9 +/- 5.6 mm Hg and the mean left atrial-right atrial pressure gradient was 21.1 +/- 5.1 mm Hg. Seven of the 13 patients have survived and have now reached a median age of 6.5 years. Balloon atrial septostomy was adequate for long-term survival in one patient; all of the others have required surgical atrial septectomy. Progressive obstruction of the foramen ovale is part of the natural history of left AV valve atresia, and obstruction develops despite the absence of a left atrial-right atrial gradient during newborn study. Balloon atrial septostomy is recommended during the neonatal period in all patients with left AV valve atresia, even in the absence of an interatrial gradient. Because early surgical atrial septectomy is usually necessary for long-term survival, these patients should have serial noninvasive evaluation of the patency of the interatrial communication.