An unusual encounter of a "cobra" in the heart: rare appearance of an Amplatzer Septal Occluder.

This article presents the unusual appearance of a "cobra" due to "acute bending" of the proximal part and partial opening of the distal part of the left atrial disk of an Amplatzer Septal Occluder during the process of transcatheter closure of a secundum atrial septal defect in a 6-year-old boy. The possible reasons and method to overcome this technical problem, which resulted in successful occlusion of the atrial septal defect, are discussed.