Progression to late complete atrioventricular block following amplatzer device closure of atrial septal defect in a child.

Atrial septal defect (ASD) closure by interventional catheterization techniques has been widely accepted and is considered a standard treatment for this congenital heart defect. We report the case of a 6-year-old girl who presented with progression of first-degree atrio-ventricular (AV) block to symptomatic, complete heart block after ASD closure with an Amplatzer septal occluder (ASO). Although she received steroids immediately after the procedure when second-degree AV block was seen, her AV conduction slowly deteriorated over 4 years, requiring permanent pacemaker implantation. We can only speculate that the injury to the conduction system was the result of persistent trauma, ischemia, or progressive scarring caused by the ASO on the AV nodal region. It is uncertain if early device removal would have prevented this complication. This case highlights the importance of cardiac rhythm monitoring following ASO implantation for ASD closure on long-term follow-up.